0000950170-23-041422 | 10-Q | XBRL Viewer

Research and Development Tax Credit Receivable (Tables)

6 Months Ended

Jun. 30, 2023

Research and Development Tax Credit Receivable [Abstract]

Summary of Amounts Recognized to Offset Research and Development Expense

The following table below outlines the changes to the research and development tax credit receivable, including amounts recognized as an offset to research and development expense during the periods (amounts in thousands):


	Three Months Ended					Six Months Ended
	2023		2022			2023		2022
Balance at beginning of period	$	6,844	$	16,649		$	5,942	$	30,723
Recognition of credit claims as offset to research and development expense		3,602		1,764			4,371		5,101
Receipt of credit claims		—		(1,916	)		-		(18,390	)
Foreign currency translation		180		(1,321	)		313		(2,258	)
Balance at end of period	$	10,626	$	15,176		$	10,626	$	15,176

Intangible Assets, Net

6 Months Ended

Jun. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets, Net

. Intangible assets, net

Intangible assets, net of accumulated amortization, consisted of the following (in thousands):


	As of June 30, 2023
	Cost		Accumulated Amortization			Net
License milestones	$	4,168	$	(694	)	$	3,474
Total	$	4,168	$	(694	)	$	3,474

	As of December 31, 2022
	Cost		Accumulated Amortization			Net
License milestones	$	4,069	$	(509	)	$	3,560
Total	$	4,069	$	(509	)	$	3,560

License intangibles consist of capitalized milestone payments made upon receiving regulatory approval of Libmeldy in the EU. The license intangibles are being amortized on a straight-line basis over the remaining useful life of the related patents of approximately twelve years. For the three and six months ended June 30, 2023, amortization of intangible assets totaled $0.1 million and $0.2 million, respectively. For the three and six months ended June 30, 2022, amortization of intangible assets totaled $0.1 million and $0.2 million, respectively. The effect of foreign currency translation on the net carrying value of intangible assets for the three and six months ended June 30, 2023, was $0.1 million. The effect of foreign currency translation on the net carrying value of intangible assets for each of the three and six months ended June 30, 2022, was $0.2 million. The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands):


	As of June 30, 2023
2023 (remaining six months)	$	171
2024		342
2025		342
2026		342
2027		342
Thereafter		1,935
Total	$	3,474

Product Revenue, Net - Summary as Components of Balance Sheets (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Reduction of accounts receivable, net	$ 996	$ 4,390
Component of accrued expenses and other current liabilities	4,005	2,300
Total revenue-related reserves	$ 5,001	$ 6,690

Restructuring Charges - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Restructuring Cost And Reserve [Line Items]
Research and development	$ 16,695,000	$ 21,965,000	$ 32,688,000	$ 50,199,000
Selling, general and administrative	$ 10,992,000	$ 13,730,000	22,127,000	27,029,000
Restructuring charges			$ 0	2,481,000
Neurometabolic Diseases and Early Research Programs
Restructuring Cost And Reserve [Line Items]
Research and development				1,600,000
Selling, general and administrative				400,000
Neurometabolic Diseases and Early Research Programs \| Employee-Related Termination Costs
Restructuring Cost And Reserve [Line Items]
One-time charge				$ 1,900,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Sale of voting and non-voting ordinary shares, net of allocated issuance costs	$ 953	$ 889

Intangible Assets, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Finite Lived Intangible Assets [Line Items]
Intangible asset, useful life	12 years		12 years
Amortization of intangible assets	$ 0.1	$ 0.1	$ 0.2	$ 0.2
Effect of foreign currency translation on the net carrying value of intangible assets	$ 0.1	$ 0.2	$ 0.1	$ 0.2

Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Summary Of Significant Accounting Policies [Abstract]
Cash and cash equivalents	$ 38,273	$ 68,424
Restricted cash	4,215	4,215
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 42,488	$ 72,639	$ 57,736	$ 60,178

Private Placement Transaction Share - Additional Information (Details) $ / shares in Units, $ in Thousands				3 Months Ended		6 Months Ended
	Jun. 22, 2023 USD ($) shares	Mar. 10, 2023 USD ($) shares	Mar. 06, 2023 USD ($) shares	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jan. 01, 2025 $ / shares	Dec. 31, 2024 $ / shares	Jun. 30, 2023 £ / shares	Jun. 30, 2023 USD ($) shares	Jun. 22, 2023 £ / shares	Jun. 22, 2023 USD ($) $ / shares shares	Mar. 10, 2023 £ / shares	Mar. 10, 2023 USD ($) $ / shares shares	Mar. 06, 2023 £ / shares	Mar. 06, 2023 USD ($) shares	Dec. 31, 2022 £ / shares	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares	4,250,000	56,666,900
Ordinary shares, nominal value \| £ / shares									£ 0.10		£ 0.1		£ 0.1				£ 0.10
Warrants to purchase ordinary shares \| shares												46,750,000		62,333,590
Gross proceeds of offering	$ 34,000	$ 34,000
Issuance costs						$ 889
Equity					$ 101,655					$ 109,047								$ 98,264	$ 146,272	$ 175,646	$ 209,950
Changes in fair value						$ (12,057)
Securities Purchase Agreement \| 2023 Private Placement
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares			99,166,900
Ordinary shares, nominal value \| £ / shares															£ 0.1
Warrants to purchase ordinary shares \| shares																109,083,590
Warrants expiration, description						The warrants will expire at the conclusion of the 30-day exercise period or on March 10, 2026, whichever is earlier.
Warrants exercisable term					30 days
Shares sold in fixed combinaton of warrants as units						The 2023 Private Placement consisted of two closings, referred to herein as the "First Closing" and "Second Closing". At each closing, the Shares were sold in fixed combinations with the warrants as units, with each unit consisting of 10 Shares and 1 accompanying warrant to purchase 11 shares. The warrants are contingently exercisable for 30 days following (i) the Company’s public announcement of its receipt of marketing approval of its biologics license application (“BLA”) submitted to the FDA with respect to OTL-200 (the “Vesting Event”) and (ii) receipt of shareholder approval to increase the number of authorized shares.
Fair value of financial instruments																$ 34,000
Issuance costs	1,200	1,100	$ 500
Gain on mark-to-market adjustment		3,600
Equity												$ 19,700		$ 24,000
Changes in fair value	9,700
Warants outstanding \| shares										109,083,590
Warrant exercisable \| shares										0
Securities Purchase Agreement \| 2023 Private Placement \| Scenario Forecast
Class of Stock [Line Items]
Warrants to purchase price per share \| $ / shares							$ 0.95	$ 1.1
Securities Purchase Agreement \| 2023 Private Placement \| Initial Closing
Class of Stock [Line Items]
Warrants to purchase ordinary shares \| shares														62,333,590
Warrants to purchase price per share \| $ / shares														$ 6
Gross proceeds of offering		34,000
Deducting offering expenses		900
Securities Purchase Agreement \| 2023 Private Placement \| Second Closing
Class of Stock [Line Items]
Warrants to purchase ordinary shares \| shares												46,750,000
Warrants to purchase price per share \| $ / shares												$ 8
Gross proceeds of offering	34,000
Deducting offering expenses	1,200
Securities Purchase Agreement \| 2023 Private Placement \| PIPE Warrants
Class of Stock [Line Items]
Fair value of financial instruments																6,400
Issuance costs	200	200
Warrant liability												$ 4,600
Changes in fair value				$ 1,400		$ 1,200
Securities Purchase Agreement \| 2023 Private Placement \| PIPE Units
Class of Stock [Line Items]
Fair value of financial instruments																20
Issuance costs		200
Derecognized assets												$ 9,600
Changes in fair value				$ 9,700		$ 9,600
Securities Purchase Agreement \| 2023 Private Placement \| Ordinary Shares
Class of Stock [Line Items]
Fair value of financial instruments																$ 27,500
Issuance costs	$ 1,000	$ 900
Securities Purchase Agreement \| 2023 Private Placement \| Ordinary Shares \| Initial Closing
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares		40,053,500
Securities Purchase Agreement \| 2023 Private Placement \| Ordinary Shares \| Second Closing
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares	13,408,074
Securities Purchase Agreement \| 2023 Private Placement \| Non-voting Ordinary Shares \| Initial Closing
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares		16,613,400
Securities Purchase Agreement \| 2023 Private Placement \| Non-voting Ordinary Shares \| Second Closing
Class of Stock [Line Items]
Number of ordinary shares issued and sold \| shares	29,091,926

Notes Payable - Summary of Notes Payable (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Notes and Loans, Noncurrent [Abstract]
Notes payable, net of issuance costs	$ 27,297	$ 31,970
Less: current portion	9,429	(9,429)
Notes payable, net of current portion	17,868	22,541
Accretion related to final payment	572	450
Notes payable, long term	$ 18,440	$ 22,991

Intangible Assets, Net (Tables)

6 Months Ended

Jun. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets Net of Accumulated Amortization

Intangible assets, net of accumulated amortization, consisted of the following (in thousands):


	As of June 30, 2023
	Cost		Accumulated Amortization			Net
License milestones	$	4,168	$	(694	)	$	3,474
Total	$	4,168	$	(694	)	$	3,474

	As of December 31, 2022
	Cost		Accumulated Amortization			Net
License milestones	$	4,069	$	(509	)	$	3,560
Total	$	4,069	$	(509	)	$	3,560

Schedule of Estimated Future Amortization For Intangible Assets

The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands):


	As of June 30, 2023
2023 (remaining six months)	$	171
2024		342
2025		342
2026		342
2027		342
Thereafter		1,935
Total	$	3,474

Product Revenue, Net - Schedule of Net Revenue by Product (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Net revenue	$ 7,314	$ 4,368	$ 8,551	$ 9,892
Libmeldy
Disaggregation of Revenue [Line Items]
Net revenue	6,651	3,145	7,185	8,204
Strimvelis
Disaggregation of Revenue [Line Items]
Net revenue		636		636
Product
Disaggregation of Revenue [Line Items]
Net revenue	$ 6,651	$ 3,781	$ 7,185	$ 8,840

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-4

+ Details

Product Revenue, Net (Tables)

6 Months Ended

Jun. 30, 2023

Revenue from Contract with Customer [Abstract]

Disaggregated Product Revenue

The following table presents the Company's net revenue by product (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Libmeldy	$	6,651	$	3,145	$	7,185	$	8,204
Strimvelis		—		636		—		636
Total	$	6,651	$	3,781	$	7,185	$	8,840

Summary of Activity of Product Revenue Allowance and Reserve Categories

Activity in each of the product revenue allowance and reserve categories for Libmeldy is summarized as follows (in thousands):


	Trade discounts and allowances			Government rebates		Total
Balance as of December 31, 2022	$	4,390		$	2,300	$	6,690
Provision Related to sales in the current year		3,950			1,655		5,605
Credits and payments made during the period		(7,344	)		—		(7,344	)
Foreign currency translation		—			50		50
Balance as of June 30, 2023	$	996		$	4,005	$	5,001

Summary as Components of Balance Sheets

The total reserves described above are summarized as components of the Company's condensed consolidated balance sheets as follows (in thousands):


	As of June 30, 2023		As of December 31, 2022
Reduction of accounts receivable, net	$	996	$	4,390
Component of accrued expenses and other current liabilities		4,005		2,300
Total revenue-related reserves	$	5,001	$	6,690

Product Revenue, Net - Summary of Activity of Product Revenue Allowance and Reserve Categories (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance as of December 31, 2022	$ 6,690
Provision Related to sales in the current year	5,605
Credits and payments made during the period	(7,344)
Foreign currency translation	50
Balance as of June 30, 2023	5,001
Trade Discounts and Allowances
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance as of December 31, 2022	4,390
Provision Related to sales in the current year	3,950
Credits and payments made during the period	(7,344)
Balance as of June 30, 2023	996
Government Rebates
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance as of December 31, 2022	2,300
Provision Related to sales in the current year	1,655
Foreign currency translation	50
Balance as of June 30, 2023	$ 4,005

Notes Payable

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

Notes Payable

. Notes payable

In May 2019, the Company entered into a senior term facilities agreement, which was amended in April 2020 (the “Original Credit Facility”) with MidCap Financial (Ireland) Limited (“MidCap Financial”), as agent, and additional lenders from time to time (together with MidCap Financial, the “Lenders”), to borrow up to $75.0 million in term loans.

In May 2021, the Company amended and restated the Original Credit Facility (the “Amended Credit Facility”). Under the Amended Credit Facility, the Lenders agreed to make term loans available to the Company in the aggregate amount of $100.0 million, including

increasing the principal on the initial term loan to $33.0 million, from $25.0 million. In January 2023, the Company amended and restated the credit facility to change the reference rate from the London Interbank Offered Rate ("LIBOR") to the Secured Overnight Financing Rate ("SOFR"). As of June 30, 2023, the Company has borrowed $33.0 million under the Amended Credit Facility.

In March 2023, the Company notified MidCap Financial of its voluntary cancellation of each Lender's remaining commitments under the Amended Credit Facility. As a result of this notice, the Company can no longer draw on the remaining $67.0 million that was available on the Amended Credit Facility. Additionally, MidCap agreed to waive certain restrictive covenants of the Amended Credit Facility, specifically related to restrictions on the Company's ability to dispose of intellectual property related to deprioritized products.

The Company's borrowings under the Amended Credit Facility bear interest at an annual rate equal to 5.95% plus SOFR plus a 0.10% annual increase to the annual rate. The Company was required to make interest only payments on the term loan for 18 months following the date of the Amended Credit Facility. The term loan under the Amended Credit Facility began amortizing on the 18-month anniversary of the Amended Credit Facility (December 2022), with the Company commencing equal monthly payments of principal plus interest to the Lenders to be made in consecutive monthly installments until the loan maturity date in May 2026. In addition, a final payment of 3.5% is due on the loan maturity date. The Company is accruing the final payment amount of $1.2 million associated with the Amended Credit Facility, to outstanding debt by charges to interest expense using the effective-interest method from the date of issuance through the loan maturity date.

The Amended Credit Facility includes affirmative and negative covenants. The affirmative covenants include, among others, covenants requiring the Company to maintain their legal existence and governmental approvals, deliver certain financial reports, maintain insurance coverage, maintain property, pay taxes, satisfy certain requirements regarding accounts and comply with laws and regulations. The negative covenants include, among others, restrictions on the Company transferring collateral, incurring additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions, making investments, creating liens, amending material agreements and organizational documents, selling assets, changing the nature of the business and undergoing a change in control, subject to certain exceptions.

Notes payable consist of the following (in thousands):


	June 30,			December 31,
	2023			2022
Notes payable, net of issuance costs	$	27,297		$	31,970
Less: current portion		(9,429	)		(9,429	)
Notes payable, net of current portion		17,868			22,541
Accretion related to final payment		572			450
Notes payable, long term	$	18,440		$	22,991

As of June 30, 2023, the estimated future principal payments due are as follows (in thousands):


	Aggregate Minimum Payments
2023 (remaining six months)	$	4,714
2024		9,429
2025		9,429
2026		5,084
Total		28,656
Less current portion		(9,429	)
Less unamortized portion of final payment		(584	)
Less unamortized debt issuance costs		(203	)
Notes payable, long term	$	18,440

During the three months ended June 30, 2023 and 2022, the Company recognized $0.9 million and $0.7 million of interest expense related to the term loan, respectively. During the six months ended June 30, 2023 and 2022, the Company recognized $1.9 million and $1.3 million of interest expense related to the term loan, respectively. The effective annual interest rate as of June 30, 2023, was approximately 12.38%.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Paragraph 1
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued Liabilities and Other Liabilities [Abstract]
Accrued external research and development expenses	$ 10,985	$ 11,230
Accrued payroll and related expenses	9,132	12,312
Accrued professional fees	2,588	2,263
Accrued other	3,459	2,647
Accrued governmental rebates	4,005	2,300
Strimvelis liability - current portion	3,617	3,685
Total accrued expenses and other current liabilities	$ 33,786	$ 34,437

Collaboration Revenue

6 Months Ended

Jun. 30, 2023

Collaborative Arrangement [Abstract]

Collaboration Revenue

15. Collaboration revenue

On July 1, 2021, the Company entered into a strategic collaboration with Pharming Group N.V. (“Pharming”) to research, develop, manufacture, and commercialize OTL-105, an investigational ex vivo autologous HSC gene therapy for the treatment of hereditary angioedema (HAE), a life-threatening rare disorder that causes recurring swelling attacks in the face, throat, extremities and abdomen (the “Collaboration Agreement”).

Under the terms of the Collaboration Agreement, Pharming was granted worldwide rights to OTL-105 and will be responsible for clinical development, regulatory filings and commercialization of the investigational gene therapy, including associated costs. The Company will lead the completion of IND-enabling activities and oversee manufacturing of OTL-105 during pre-clinical and clinical development, which will be funded by Pharming. In addition, both the Company and Pharming will explore the application of non-toxic conditioning regimen for use with OTL-105 administration.

The Company received an upfront payment of $10.0 million in cash from Pharming and will receive cost reimbursements for ongoing research, development, and manufacturing services to be provided under the Collaboration Agreement. The Company is also eligible to receive up to $189.5 million in development, regulatory and sales milestones as well as mid-single to low double-digit percentage royalty payments on future worldwide sales.

The Company also entered into a Share Purchase Agreement with Pharming on July 1, 2021 (the “Pharming SPA”), pursuant to which the Company issued 1,227,738 ordinary shares to Pharming for total consideration of $7.5 million. The consideration is payment for the fair value of ordinary shares with a fair value of $4.1 million plus a $3.4 million premium on the fair value of the Company’s ordinary shares. The “Collaboration Agreement” and the “Pharming SPA” are referred to together as the “Pharming Agreements.”

Accounting Analysis

At the commencement of the arrangement, two units of accounting were identified, which include: 1) the issuance of 1,227,738 of the Company’s ordinary shares as part of the Pharming SPA and 2) the license and collaboration agreement, which conveys the license and provides for the Company to provide research, development, manufacturing services for OTL-105. The Pharming Agreements were entered into concurrently as part of a single commercial objective and the Company considers them a single arrangement for accounting purposes. The total upfront payments of $17.5 million are comprised of $4.1 million attributed to the equity sold to Pharming and $13.4 million attributed to the Collaboration Agreement.

The Company accounts for the Collaboration Agreement component within the scope of ASC Topic 606, Revenue from Contracts with Customers. The Company has concluded that the conveyance of the license for the HAE program and the provision of research, development, and manufacturing services for the HAE program represent a series of distinct services that are accounted for as a single performance obligation within the Collaboration Agreement.

The Company determined that the transaction price includes: the $13.4 million attributed to the Collaboration Agreement and the variable consideration for estimated reimbursement payments at agreed upon contractual rates to be received from Pharming for the Company’s on-going research, development, and manufacturing services. There is uncertainty as to whether the future milestone payments will ultimately be achieved. Accordingly, the Company has fully constrained the variable consideration associated with the milestones. The royalty payments were also excluded from the transaction price as the Company is not required to estimate variable consideration for the royalty payments. The Company re-evaluates the transaction price as of the end of each reporting period.

The Company recognizes revenue associated with the performance obligation as the research, development, and manufacturing services are provided using an input method, based on the cumulative costs incurred compared to the total estimated costs expected to be incurred to satisfy the performance obligation. The transfer of control to the customer occurs over the time period that the research, development and manufacturing services are provided by the Company.

For the three and six months ended June 30, 2023, the Company recognized collaboration revenue under the Collaboration Agreement of $0.7 million and $1.4 million, respectively. For the three and six months ended June 30, 2022, the Company recognized collaboration revenue under the Collaboration Agreement of $0.6 million and $1.1 million, respectively. As of June 30, 2023 there is $0.8 million and $10.8 million of current and long-term deferred revenue, respectively, related to the Collaboration Agreement.

Inventory

6 Months Ended

Jun. 30, 2023

Inventory Disclosure [Abstract]

Inventory

4. Inventory

Inventory consists of the following (in thousands):


	June 30,		December 31,
	2023		2022
Raw materials	$	6,712	$	3,193
Work in process		225		207
Total inventory	$	6,937	$	3,400

The Company currently has $4.8 million of inventory capitalized related to Libmeldy in Europe that is currently in the process of regulatory review.

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 6,712	$ 3,193
Work in process	225	207
Total inventory	$ 6,937	$ 3,400

Share-based Compensation - Summary of Option Activity (Details)	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Number of Options, Outstanding at December 31, 2022 \| shares	16,424,167
Number of Options, Granted \| shares	5,085,330
Number of Options, Exercised \| shares	(332,180)
Number of Options, Forfeited \| shares	(795,167)
Number of Options, Outstanding at June 30, 2023 \| shares	20,382,150
Number of Options, Vested and expected to vest at June 30, 2023 \| shares	20,382,150
Number of Options, Exercisable, June 30, 2023 \| shares	10,452,810
Weighted Average Exercise Price, Outstanding at December 31, 2022 \| $ / shares	$ 1.56
Weighted Average Exercise Price, Granted \| $ / shares	0.49
Weighted Average Exercise Price, Exercised \| $ / shares	0.12
Weighted Average Exercise Price, Forfeited \| $ / shares	4.27
Weighted Average Exercise Price, Outstanding at June 30, 2023 \| $ / shares	1.21
Weighted Average Exercise Price, Vested and expected to vest at June 30, 2023 \| $ / shares	1.21
Weighted Average Exercise Price, Exercisable at June 30, 2023 \| $ / shares	$ 1.82

Fair Value Measurements and Marketable Securities - Schedule of Aggregate Fair Values of PIPE Warrant Liability and PIPE Unit Liability (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
PIPE Warrant Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2022	$ 0
Issuances during period	11,098
Change in fair value	1,168
Balance at March 31, 2023	12,266
PIPE Units Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2022	0
Issuances during period	25
Change in fair value	(9,668)
Settlement of PIPE Unit liability upon Second Closing	9,643
Balance at March 31, 2023	$ 0

Fair Value Measurements and Marketable Securities

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements and Marketable Securities

3. Fair value measurements and marketable securities

Fair value measurements

The following tables present information about the Company’s financial assets and liabilities that have been measured at fair value as of June 30, 2023, and December 31, 2022, and indicate hierarchy of valuation inputs utilized to determine such fair value (in thousands):


	Fair Value Measurements as of June 30, 2023
	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents
Money market funds	$	3,305	$	—	$	—	$	3,305
U.S. treasuries		—		1,995		—		1,995
Commercial paper		—		6,989		—		6,989
Total cash equivalents	$	3,305	$	8,984	$	—	$	12,289
Marketable securities
U.S. government securities	$	—	$	12,326	$	—	$	12,326
U.S. treasuries		—		14,277		—		14,277
Corporate bonds		—		16,118		—		16,118
Commercial paper		—		69,747		—		69,747
Total marketable securities	$	—	$	112,468	$	—	$	112,468
Total Assets	$	3,305	$	121,452	$	—	$	124,757

Liabilities
PIPE Warrant liability	$	—	$	—	$	12,266	$	12,266
Total Liabilities	$	—	$	—	$	12,266	$	12,266


	Fair Value Measurements as of December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents
Money market funds	$	1,239	$	—	$	—	$	1,239
U.S. treasuries		—		6,600		—		6,600
U.S. government securities		—		5,200		—		5,200
Commercial paper		—		14,122		—		14,122
Total cash equivalents	$	1,239	$	25,922	$	—	$	27,161
Marketable securities
U.S. government securities	$	—	$	1,984	$	—	$	1,984
Corporate bonds		—		25,475		—		25,475
Commercial paper		—		47,867		—		47,867
Total marketable securities	$	—	$	75,326	$	—	$	75,326
Total Assets	$	1,239	$	101,248	$	—	$	102,487

The Company classifies its money market funds as Level 1 assets since it measures fair value using quoted prices in active markets for identical assets. The Level 2 assets include commercial paper, U.S. government securities, U.S. treasuries, and corporate bonds and are valued based on quoted prices for similar assets in active markets and inputs other than quoted prices that are derived from observable market data.

The Company evaluates transfers between levels at the end of each reporting period. There were no transfers between Level 1 and Level 2 assets during the periods presented.

The PIPE Warrants (as defined in Note 12) and PIPE Units (as defined in Note 12) associated with the 2023 Private Placement did not meet the criteria for equity classification, and are therefore accounted for as liabilities at fair value. Refer to Note 12 for the accounting analysis of the PIPE Warrants and PIPE Units. The fair values of the PIPE Warrants and PIPE Units are based on significant unobservable inputs, which represent Level 3 measurements within the fair value hierarchy.

The fair value of the PIPE Warrants, inclusive of the warrants to be issued in the Second Closing and the warrants ultimately issued in the Second Closing, was estimated using the Black-Scholes option pricing model, which was then adjusted by the weighted probability of the timing of the anticipated achievement of FDA marketing approval for the sale of Libmeldy in the United States and further adjusted by the probability of the occurrence of achievement of FDA marketing approval for the sale of Libmeldy in the United States.

The fair value of the PIPE Units prior to the second closing of the 2023 Private Placement was estimated as the residual of the fair value of the share and warrant units to be sold in the second closing minus the second closing sales price of the share and warrant units to be sold. To calculate the fair value of the shares to be sold in the second closing, the Company utilized the stock price of its ADSs as of the valuation date and discounted it using a discount for lack of marketability ("DLOM").

The second closing was completed in June 2023, upon which, the Company recorded a final fair value adjustment and derecognized the value ascribed to the PIPE Units instrument. The fair value of the PIPE Units at the time of the second closing was calculated by estimating the fair value of the PIPE Warrants and the unregistered shares issued in the second closing. To calculate the fair value of the shares issued in the second closing, the Company utilized the stock price of its ADSs as of the valuation date and discounted it using a DLOM relating to the unregistered status of the shares.

The significant unobservable inputs used in the valuation models during the three months ended June 30, 2023, to measure the fair value of the PIPE Warrants and PIPE Units are as follows:


	PIPE Unit Liability		PIPE Warrant Liability
Valuation date	June 22, 2023		June 30, 2023
Expected warrant exercise date	July 30, 2024	April 30, 2025	July 30, 2024	April 30, 2025
Black-Scholes inputs
Anticipated common stock price (at exercise date)	$10.40	$10.07	$10.39	$10.07
Expected term (in years)	1.11	1.86	1.08	1.84
Expected volatility	75.0%	74.8%	75.6%	74.5%

Other significant unobservable inputs
Implied probabilities of occurrence of Second Closing and FDA Approval	30.5%		34.6%
Discount for lack of marketability	5.0%		0%

The following table provides a rollforward of the aggregate fair values of the Company’s PIPE Warrant liability and PIPE Unit liability, for which fair values are determined using Level 3 inputs (in thousands):


	PIPE Warrant Liability		PIPE Unit Liability
Balance at December 31, 2022	$	—	$	—
Issuances during period		11,098		25
Change in fair value		1,168		(9,668	)
Settlement of PIPE Unit liability upon Second Closing		—		9,643
Balance at June 30, 2023	$	12,266	$	-

Marketable securities

The following tables summarize the amortized cost and fair value of the Company's available-for-sale marketable debt securities (in thousands):


	June 30, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
U.S. government securities	$	12,338	$	1	$	(13	)	$	—	$	12,326
U.S. treasuries		16,280		—		(8	)		—	$	16,272
Corporate bonds		16,232		—		(114	)		—		16,118
Commercial paper		76,801		—		(65	)		—		76,736
Total	$	121,651	$	1	$	(200	)	$	—	$	121,452


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
U.S. government securities	$	7,188	$	1	$	(6	)	$	—	$	7,183
U.S. treasuries		6,599		1		—			—	$	6,600
Corporate bonds		25,656		—		(180	)		—	$	25,476
Commercial paper		62,038		3		(52	)		—		61,989
Total	$	101,481	$	5	$	(238	)	$	—	$	101,248

All investments in an unrealized loss position were in this position for less than 12 months. The Company evaluated its securities for potential impairment and considered the decline in market value to be primarily attributable to current economic and market conditions. Additionally, the Company does not intend to sell the securities in an unrealized loss position and does not expect it will be required to

sell the securities before recovery of the unamortized cost basis. Given the Company's intent and ability to hold such securities until recovery, and the lack of a significant change in credit risk for these investments, the Company does not consider these investments to be impaired as of June 30, 2023.

There were no realized gains or losses recognized on investments for the three or six months ended June 30, 2023.

The following table summarizes the Company’s debt securities by contractual maturity, as of June 30, 2023, and December 31, 2022 (in thousands):


	June 30, 2023		December 31, 2022
Maturities in one year or less	$	117,460	$	98,277
Maturities between one and three years		3,992		2,971
Total	$	121,452	$	101,248

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Research and Development Tax Credit Receivable - Summary of Amounts Recognized to Offset Research and Development Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Tax Credit Carryforward [Line Items]
Foreign currency translation			$ (7,500)	$ (24,300)
United Kingdom \| Research and Development Expense
Tax Credit Carryforward [Line Items]
Balance at beginning of period	$ 6,844	$ 16,649	5,942	30,723
Recognition of credit claims as offset to research and development expense	3,602	1,764	4,371	5,101
Receipt of credit claims		(1,916)		(18,390)
Foreign currency translation	180	(1,321)	313	(2,258)
Balance at end of period	$ 10,626	$ 15,176	$ 10,626	$ 15,176

Inventory (Tables)

6 Months Ended

Jun. 30, 2023

Inventory Disclosure [Abstract]

Schedule of Inventory

Inventory consists of the following (in thousands):


	June 30,		December 31,
	2023		2022
Raw materials	$	6,712	$	3,193
Work in process		225		207
Total inventory	$	6,937	$	3,400

Notes Payable - Summary of Estimated Future Principal Payments Due (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Long-Term Debt, Fiscal Year Maturity [Abstract]
2023 (remaining six months)	$ 4,714
2024	9,429
2025	9,429
2026	5,084
Total	28,656
Less: current portion	(9,429)
Less: unamortized portion of final payment	584
Less: unamortized debt issuance costs	(203)
Notes payable, long term	$ 18,440	$ 22,991

Nature of the Business and Liquidity

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of the Business and Liquidity

1. Nature of the Business and Liquidity

Orchard Therapeutics plc (the “Company”) is a global gene therapy company dedicated to transforming the lives of people affected by severe diseases through the development of innovative, potentially curative gene therapies. The Company’s ex vivo autologous hematopoietic stem cell (“HSC”) gene therapy approach harnesses the power of genetically modified blood stem cells and seeks to correct the underlying cause of disease in a single administration. The Company has a portfolio that includes a commercial-stage product and research and development-stage product candidates.

The Company is a public limited company incorporated pursuant to the laws of England and Wales. The Company has American Depositary Shares (“ADSs”) registered with the U.S. Securities and Exchange Commission (the “SEC”). The ADSs were listed on the Nasdaq Global Select Market on October 31, 2018, and were transferred to the Nasdaq Capital Market on September 13, 2022. The Company’s ADSs each represent ten ordinary shares of the Company. Each holder of ordinary shares is entitled to one vote per ordinary share and to receive dividends when and if such dividends are recommended by the board of directors and declared by the shareholders. The Company did not declare any dividends in 2023 or 2022. Share information presented in these unaudited condensed consolidated financial statements are presented on an ordinary share basis and not on an ADS converted basis unless otherwise indicated.

In January 2022, the Company began to generate revenue from product sales of Libmeldy™ in Europe following the approval of Libmeldy by the European Commission in December 2020 for the treatment of early onset metachromatic leukodystrophy (“MLD”), characterized by biallelic mutations in the arylsulfatase-A ("ARSA") gene leading to a reduction of the ARSA enzymatic activity in children with (i) late infantile or early juvenile forms, without clinical manifestations of the disease, or (ii) the early juvenile form, with early clinical manifestations of the disease, who still have the ability to walk independently and before the onset of cognitive decline.

On March 6, 2023, the Company entered into a Securities Purchase Agreement (“SPA” or “PIPE”) pursuant to which the Company agreed to sell ordinary shares, non-voting ordinary shares, and warrants to purchase ordinary shares or non-voting ordinary shares in an unregistered offering (the "2023 Private Placement"). The 2023 Private Placement consists of two closings. On March 10, 2023, the Company completed the first closing and issued and sold (i) 56,666,900 ordinary shares and non-voting ordinary shares, nominal value £0.10 per share and (ii) warrants to purchase an aggregate of 62,333,590 ordinary shares or non-voting ordinary shares, at a purchase price of $6.00 per unit, where each unit consists of ten shares and an accompanying warrant to purchase eleven shares. The initial closing of the 2023 Private Placement resulted in gross proceeds of $34.0 million.

On June 22, 2023, the Company completed the second closing of the 2023 Private Placement and sold (i) 42,500,00 ordinary shares and non-voting ordinary shares, nominal value £0.10 per share and (ii) warrants to purchase an aggregate of 46,750,000 ordinary shares or non-voting ordinary shares, at a purchase price of $8.00 per unit, where each unit consists of ten shares and an accompanying warrant to purchase eleven shares. The second closing of the 2023 Private Placement resulted in gross proceeds of $34.0 million. Refer to Note 12 for further discussion of the 2023 Private Placement.

The Company’s business is subject to risks and uncertainties common to development-stage companies in the biotechnology industry. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s technology will be obtained, that any products developed will obtain necessary government regulatory approval or that any products, if approved, will be commercially viable. The Company operates in an environment of rapid technological innovation and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, consultants and service providers. Even if the Company’s product development efforts are successful in gaining regulatory approval, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

Through June 30, 2023, the Company funded its operations primarily with proceeds from the sale of equity securities, including ADSs in the Company’s initial public offering (“IPO”) and follow-on offering, ordinary shares in the private placements, and convertible preferred shares. The Company has also financed its operations through proceeds from the Company’s senior term facilities agreement with MidCap Financial (Ireland) Limited, research grants from the California Institute of Regenerative Medicine (“CIRM”), upfront payments from the Company’s collaboration agreement and share purchase agreement with Pharming Group N.V., proceeds from the sales of the Company's Libmeldy product, and reimbursements associated with two UK research and development tax relief programs, the Small and Medium-sized Enterprises research and development tax credit (“SME”) program and the Research and Development Expenditure (“RDEC”) program. The Company has incurred recurring losses since its inception and expects to continue to generate operating losses for the foreseeable future.

The Company expects that its cash, cash equivalents, and marketable securities on hand as of June 30, 2023, of $150.7 million, together with expected proceeds from sales of Libmeldy, will be sufficient to fund its operations, capital expenditures and debt service payments for at least twelve months from the date of filing of this Form 10-Q. The Company will seek additional funding through private or public equity financings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborations or other arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company's shareholders. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. If the Company is unable

to obtain funding, the Company will be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all.

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Ordinary Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2021	$ 209,950	$ 16,253	$ 940,675	$ 3,246	$ (750,224)
Balance, Shares at Dec. 31, 2021		125,674,095
Share-based compensation expense	4,660		4,660
Exercise of share options	(1)	$ 28	(29)
Exercise of share options, Shares		222,381
Vesting of restricted stock units, net of shares withheld for taxes	(3)	$ 1	(4)
Vesting of restricted stock units, net of shares withheld for taxes, shares		3,217
Ordinary shares issued as part of a consulting agreement	1	$ 1
Ordinary shares issued as part of consulting agreement, Shares		5,252
Foreign currency translation	5,595			5,595
Unrealized loss on available for sale debt securities	(260)			(260)
Net loss attributable to ordinary shareholders	(44,296)				(44,296)
Balance at Mar. 31, 2022	175,646	$ 16,283	945,302	8,581	(794,520)
Balance, Shares at Mar. 31, 2022		125,904,945
Balance at Dec. 31, 2021	209,950	$ 16,253	940,675	3,246	(750,224)
Balance, Shares at Dec. 31, 2021		125,674,095
Foreign currency translation	23,045
Unrealized loss on available for sale debt securities	(261)
Net loss attributable to ordinary shareholders	(95,212)
Balance at Jun. 30, 2022	146,272	$ 16,353	949,325	26,030	(845,436)
Balance, Shares at Jun. 30, 2022		126,436,213
Balance at Mar. 31, 2022	175,646	$ 16,283	945,302	8,581	(794,520)
Balance, Shares at Mar. 31, 2022		125,904,945
Share-based compensation expense	3,956		3,956
Exercise of share options	1	$ 24	(23)
Exercise of share options, Shares		175,153
Issuance of ESPP shares	136	$ 46	90
Issuance of ESPP shares, Shares		356,115
Foreign currency translation	17,450			17,450
Unrealized loss on available for sale debt securities	(1)			(1)
Net loss attributable to ordinary shareholders	(50,916)				(50,916)
Balance at Jun. 30, 2022	146,272	$ 16,353	949,325	26,030	(845,436)
Balance, Shares at Jun. 30, 2022		126,436,213
Balance at Dec. 31, 2022	98,264	$ 16,419	956,711	26,018	(900,884)
Balance, Shares at Dec. 31, 2022		126,947,225
Share-based compensation expense	3,512		3,512
Exercise of share options	41	$ 43	(2)
Exercise of share options, Shares		332,209
Vesting of restricted stock units, net of shares withheld for taxes	(166)	$ 40	(206)
Vesting of restricted stock units, net of shares withheld for taxes, shares		310,025
Sale of voting and non-voting ordinary shares, net of allocated issuance costs	23,073	$ 7,369	15,704
Sale of voting and non-voting ordinary shares, net of allocated issuance costs, Shares		56,666,900
Foreign currency translation	(5,731)			(5,731)
Unrealized loss on available for sale debt securities	74			74
Net loss attributable to ordinary shareholders	(17,412)				(17,412)
Balance at Mar. 31, 2023	101,655	$ 23,871	975,719	20,361	(918,296)
Balance, Shares at Mar. 31, 2023		184,256,359
Balance at Dec. 31, 2022	$ 98,264	$ 16,419	956,711	26,018	(900,884)
Balance, Shares at Dec. 31, 2022		126,947,225
Exercise of share options, Shares	332,180
Foreign currency translation	$ (7,501)
Unrealized loss on available for sale debt securities	35
Net loss attributable to ordinary shareholders	(29,719)
Balance at Jun. 30, 2023	109,047	$ 29,456	991,642	18,552	(930,603)
Balance, Shares at Jun. 30, 2023		227,215,699
Balance at Mar. 31, 2023	101,655	$ 23,871	975,719	20,361	(918,296)
Balance, Shares at Mar. 31, 2023		184,256,359
Share-based compensation expense	2,578		2,578
Issuance of ESPP shares	169	$ 59	110
Issuance of ESPP shares, Shares		455,550
Vesting of restricted stock units, net of shares withheld for taxes		$ 1	(1)
Vesting of restricted stock units, net of shares withheld for taxes, shares		3,790
Sale of voting and non-voting ordinary shares, net of allocated issuance costs	18,761	$ 5,525	13,236
Sale of voting and non-voting ordinary shares, net of allocated issuance costs, Shares		42,500,000
Foreign currency translation	(1,770)			(1,770)
Unrealized loss on available for sale debt securities	(39)			(39)
Net loss attributable to ordinary shareholders	(12,307)				(12,307)
Balance at Jun. 30, 2023	$ 109,047	$ 29,456	$ 991,642	$ 18,552	$ (930,603)
Balance, Shares at Jun. 30, 2023		227,215,699

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid external research and development expenses	$ 378	$ 881
Other prepayments	2,998	1,817
VAT receivable	712	1,077
Non-trade receivables	419	1,851
Rent deposits	1,033	960
Total prepaid expenses and other current assets	$ 5,540	$ 6,586

Share-based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Share-based Compensation

11. Share-based compensation

The Company maintains four equity compensation plans: the Orchard Therapeutics Limited Employee Share Option Plan with Non-Employee Sub-Plan and U.S. Sub-Plan (the “2016 Plan”), the Orchard Therapeutics plc 2018 Share Option and Incentive Plan (the “2018 Plan”), the 2018 Employee Share Purchase Plan (the “ESPP”), and the 2020 Inducement Equity Plan (the “Inducement Plan”). The board of directors has determined it will not make any further awards under the 2016 plan. As of June 30, 2023, there were 12,421,580 ordinary shares available for grant under the 2018 Plan, 730,500 ordinary shares available for grant under the Inducement Plan, and 1,460,590 ordinary shares available for grant under the ESPP.

The number of options and restricted stock units, the weighted average grant date fair value per stock option and per share, and the weighted average exercise price in the tables below are all shown below on a per ordinary share basis. The Company’s ADSs that are listed on the NASDAQ Capital Market each represent ten ordinary shares.

Share option activity

The following table summarizes option activity for ordinary shares under the plans for the six months ended June 30, 2023:


	Shares			Weighted Average Exercise Price per Ordinary Share
Outstanding at December 31, 2022		16,424,167		$	1.56
Granted		5,085,330			0.49
Exercised		(332,180	)		0.12
Forfeited		(795,167	)		4.27
Outstanding at June 30, 2023		20,382,150		$	1.21
Vested and expected to vest at June 30, 2023		20,382,150		$	1.21
Exercisable at June 30, 2023		10,452,810		$	1.82

The total intrinsic value of options exercised was $0.1 million for the three and six months ended June 30, 2023. The weighted-average grant date fair value of ordinary share options granted during the six months ended June 30, 2023 and 2022, was $2.81 and $0.32 per ordinary share, respectively. As of June 30, 2023, total unrecognized compensation cost related to options was $10.4 million. This amount is expected to be recognized over a weighted average period of 2.59 years.

Restricted share units

Performance-based restricted share units

In April 2020, the Company granted 195,000 performance-based restricted share units (“RSUs”) with a total grant date fair value of $1.4 million to its Chief Executive Officer, Bobby Gaspar, M.D., Ph.D. Dr. Gaspar earns one-third of the award for each of the first three to occur of four milestones (65,000 RSUs are earned for each achieved milestone). The milestones relate to specific clinical and regulatory goals which have to be achieved before December 31, 2023 in order for the underlying RSUs to be eligible to vest. Vesting for any earned shares occurs on January 2, 2024, so long as Dr. Gaspar remains continuously employed with the Company through that date. The Company determined that two of the milestones were probable of being achieved and recognized stock-compensation expense of $0.1 million and $0.8 million for the three and six months ended June 30, 2023.

Time-based restricted share units

Time-based restricted share units generally vest in equal annual installments over a three-year period.

Restricted share unit activity

The following table summarizes award activity for the six months ended June 30, 2023:


	Performance-based RSUs		Time-based RSUs			Total RSUs			Weighted Average Grant Date Fair Value per Share
Unvested at December 31, 2022		195,000		1,868,876			2,063,876		$	0.55
Granted		—		1,700,200			1,700,200			0.46
Vested		—		(609,170	)		(609,170	)		0.52
Forfeited		—		(152,806	)		(152,806	)		0.46
Unvested at June 30, 2023		195,000		2,807,100			3,002,100		$	0.51

As of June 30, 2023, total unrecognized compensation cost related to time-based RSUs was $1.1 million. This amount is expected to be recognized over a weighted average period of 2.11 years. As of June 30, 2023, the total unrecognized compensation cost related to performance-based RSUs for which vesting was deemed probable was $0.1 million, which is expected to be recognized over a period of 0.5 years. As of June 30, 2023, the total unrecognized compensation cost related to performance-based RSUs for which vesting was deemed not probable was $0.5 million, the timing of recognition will be dependent upon achievement of remaining milestones.

Share-based compensation expense

Share-based compensation expense related to share options, restricted share unit awards, and the employee stock purchase plan was classified in the unaudited condensed consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended				Six Months Ended
	2023		2022		2023		2022
Research and development	$	1,025	$	1,744	$	2,261	$	3,706
Selling, general and administrative		1,553		2,212		3,829		4,910
Total	$	2,578	$	3,956	$	6,090	$	8,616

Total share-based compensation by award type was as follows (in thousands):


	Three Months Ended				Six Months Ended
	2023		2022		2023		2022
Share options	$	2,253	$	3,774	$	4,808	$	8,282
Restricted share units		325		182		1,282		334
Total	$	2,578	$	3,956	$	6,090	$	8,616

Intangible Assets, Net - Schedule of Intangible Assets Net of Accumulated Amortization (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]
Intangible Assets, Cost	$ 4,168	$ 4,069
Intangible Assets, Accumulated Amortized	(694)	(509)
Intangible Assets, Net	3,474	3,560
License Milestones
Finite Lived Intangible Assets [Line Items]
Intangible Assets, Cost	4,168	4,069
Intangible Assets, Accumulated Amortized	(694)	(509)
Intangible Assets, Net	$ 3,474	$ 3,560

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 25	$ (219)	$ 13	$ (161)

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Notes Payable - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended		6 Months Ended
	May 31, 2021	May 31, 2019	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Debt Instrument [Line Items]
Line of credit facility agreement date		May 31, 2019
Credit facility maximum borrowings	$ 100,000,000.0	$ 75,000,000.0
Credit facility, remaining borrowings			$ 67,000,000		$ 67,000,000
Line of credit facility amortization term	18 months
Line of credit facility interest payments term	18 months
Line of credit facility, frequency of payments					monthly payments
Line of credit facility, percentage of final payment	3.50%
Final payment amount	$ 1,200,000
Term Loan
Debt Instrument [Line Items]
Debt instrument, effective annual interest rate					12.38%
Debt instrument, interest expense			$ 900,000	$ 700,000	$ 1,900,000	$ 1,300,000
LIBOR
Debt Instrument [Line Items]
Debt instrument, annual interest rate	5.95%
Initial Term Loan
Debt Instrument [Line Items]
Credit facility maximum borrowings	$ 33,000,000.0	$ 25,000,000.0
Amended Credit Facility
Debt Instrument [Line Items]
Proceeds from lines of credit					$ 33,000,000
Amended Credit Facility \| SOFR
Debt Instrument [Line Items]
Debt instrument, effective annual interest rate	0.10%

Nature of the Business and Liquidity - Additional Information (Details)			6 Months Ended
	Jun. 22, 2023 USD ($) shares	Mar. 10, 2023 USD ($) shares	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 £ / shares	Jun. 30, 2023 USD ($)	Jun. 22, 2023 £ / shares $ / shares shares	Mar. 10, 2023 £ / shares shares	Mar. 06, 2023 $ / shares	Dec. 31, 2022 £ / shares
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Ordinary shares voting rights description			Each holder of ordinary shares is entitled to one vote per ordinary share
Ordinary shares dividends declared			$ 0	$ 0
Number of ordinary shares issued and sold \| shares	4,250,000	56,666,900
Nominal value of shares issued and sold \| £ / shares					£ 0.10		£ 0.1	£ 0.1		£ 0.10
Warrants to purchase ordinary shares \| shares							46,750,000	62,333,590
Warrants to purchase price per unit \| $ / shares							8		6
Gross proceeds of offering	$ 34,000,000	$ 34,000,000
Cash, cash equivalents and marketable securities						$ 150,700,000

Income Taxes

6 Months Ended

Jun. 30, 2023

Income Tax Disclosure [Abstract]

Income Taxes

16. Income taxes

The Company recorded an income tax expense of $13 thousand and an income tax benefit of $161 thousand for the six months ended June 30, 2023 and 2022, respectively. The Company recorded income tax expense of $25 thousand and a benefit of $219 thousand for the three months ended June 30, 2023 and 2022, respectively. The Company records no income tax benefits for the net operating losses incurred in each period in the U.K. due to the uncertainty regarding the realizability of the deferred tax asset. The Company's income tax relates to its subsidiaries in Europe and the U.S. The Company's income tax computed at its effective income tax rate for the three and six months ended June 30, 2023 differed from income taxes computed at the U.K. statutory tax rate primarily due to the U.S. deduction for foreign derived intangible income, U.S. tax credits, and share-based compensation. The Company's income tax computed at its effective income tax rate for the three and six months ended June 30, 2022 differed from income taxes computed at the U.K.

statutory tax rate primarily due to the U.S. deduction for foreign derived intangible income, U.S. tax credits, share-based compensation, and provision to return adjustments.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Prepaid Expenses and Other Current Assets

6 Months Ended

Jun. 30, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Prepaid Expenses and Other Current Assets

. Prepaid expenses and other current assets

Prepaid expenses and other current assets consist of the following (in thousands):


	June 30,		December 31,
	2023		2022
Prepaid external research and development expenses	$	378	$	881
Other prepayments		2,998		1,817
VAT receivable		712		1,077
Non-trade receivables		419		1,851
Rent deposits		1,033		960
Total prepaid expenses and other current assets	$	5,540	$	6,586

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total revenue	$ 7,314	$ 4,368	$ 8,551	$ 9,892
Costs and operating expenses:
Cost of product revenue	2,189	1,122	2,556	2,693
Research and development	16,695	21,965	32,688	50,199
Selling, general and administrative	10,992	13,730	22,127	27,029
Total costs and operating expenses	29,876	36,817	57,371	79,921
Loss from operations	(22,562)	(32,449)	(48,820)	(70,029)
Other income (expense):
Interest income	1,391	213	2,420	282
Interest expense	(975)	(672)	(1,932)	(1,347)
Changes in fair value of PIPE Warrant and PIPE Unit liabilities	8,206		12,057
Other income (expense), net	1,658	(18,227)	6,569	(24,279)
Total other income (expense), net	10,280	(18,686)	19,114	(25,344)
Net loss before income taxes	(12,282)	(51,135)	(29,706)	(95,373)
Income tax benefit (expense)	(25)	219	(13)	161
Net loss attributable to ordinary shareholders	$ (12,307)	$ (50,916)	$ (29,719)	$ (95,212)
Net loss per ordinary share attributable to ordinary shareholders, basic	$ (0.07)	$ (0.4)	$ (0.18)	$ (0.75)
Net loss per ordinary share attributable to ordinary shareholders, diluted	$ (0.07)	$ (0.4)	$ (0.18)	$ (0.75)
Weighted average ordinary shares outstanding, basic	189,286,329	127,854,596	165,482,536	127,775,132
Weighted average ordinary shares outstanding, diluted	189,286,329	127,854,596	165,482,536	127,775,132
Other comprehensive income:
Foreign currency translation adjustment	$ (1,770)	$ 17,450	$ (7,501)	$ 23,045
Unrealized gain (loss) on marketable securities	(39)	(1)	35	(261)
Total other comprehensive income (loss)	(1,809)	17,449	(7,466)	22,784
Total comprehensive loss	(14,116)	(33,467)	(37,185)	(72,428)
Product Revenue, Net [Member]
Total revenue	6,651	3,781	7,185	8,840
Collaboration Revenue [Member]
Total revenue	$ 663	$ 587	$ 1,366	$ 1,052

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Summary Of Significant Accounting Policies [Line Items]
Foreign currency transaction gain (loss)	$ (7,500,000)	$ (24,300,000)
Cash collateral associated with corporate credit cards and other leases	1,300,000		$ 1,300,000
Credit losses related to outstanding accounts receivable	0
Outstanding letter of credit associated with a lease	$ 3,000,000		$ 3,000,000
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 01, 2023
Change in accounting principle, accounting standards update, immaterial effect	true
New accounting pronouncement or change in accounting principle, description	ASU 2020-04
Minimum
Summary Of Significant Accounting Policies [Line Items]
General payment terms	30 days
Maximum
Summary Of Significant Accounting Policies [Line Items]
General payment terms	90 days
Libmeldy \| Minimum
Summary Of Significant Accounting Policies [Line Items]
General payment terms	30 days
Libmeldy \| Maximum
Summary Of Significant Accounting Policies [Line Items]
General payment terms	1 year

Commitments and Contingencies

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

17. Commitments and contingencies

Legal proceedings

The Company is not a party to any material litigation and does not have contingency reserves established for any litigation liabilities.

Manufacturing and technology development master agreement with AGC Biologics

The Company is party to an Agreement with AGC Biologic S.p.A (“AGC”) pursuant to which the Company is obligated to pay AGC for a minimum product manufacturing commitment, dedicated manufacturing and development resources, and for a lease component associated with the right of use of exclusive manufacturing suites within AGC’s existing facilities. The following table outlines the current commitments associated with the agreement, as of June 30, 2023 (amounts in thousands):


Due in:	Product manufacturing commitments		Dedicated manufacturing and development resources		Exclusive transduction suites		Total AGC Commitment
2023 (remaining six months)	$	976	$	3,236	$	—	$	4,212
2024		1,952		6,472		2,169		10,593
2025		976		3,236		1,085		5,297
Total manufacturing commitments	$	3,904	$	12,944	$	3,254	$	20,102

Tabular disclosure above has been translated to U.S. Dollar, from Euro, using the period end exchange rate of €1.00 to $1.08.

Indemnification agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and senior management that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its unaudited condensed consolidated financial statements as of June 30, 2023.

Fair Value Measurements and Marketable Securities - Schedule of Amortized Cost and Fair Value of Available-for-Sale Marketable Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 121,651	$ 101,481
Gross Unrealized Gains	1	5
Gross Unrealized Losses	(200)	(238)
Fair Value	121,452	101,248
U.S. Government Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	12,338	7,188
Gross Unrealized Gains	1	1
Gross Unrealized Losses	(13)	(6)
Fair Value	12,326	7,183
U.S. Treasuries
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	16,280	6,599
Gross Unrealized Gains		1
Gross Unrealized Losses	(8)
Fair Value	16,272	6,600
Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	16,232	25,656
Gross Unrealized Losses	(114)	(180)
Fair Value	16,118	25,476
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	76,801	62,038
Gross Unrealized Gains		3
Gross Unrealized Losses	(65)	(52)
Fair Value	$ 76,736	$ 61,989

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Schedule of Annual Commitments Associated with the Contract

The following table outlines the current commitments associated with the agreement, as of June 30, 2023 (amounts in thousands):


Due in:	Product manufacturing commitments		Dedicated manufacturing and development resources		Exclusive transduction suites		Total AGC Commitment
2023 (remaining six months)	$	976	$	3,236	$	—	$	4,212
2024		1,952		6,472		2,169		10,593
2025		976		3,236		1,085		5,297
Total manufacturing commitments	$	3,904	$	12,944	$	3,254	$	20,102

Tabular disclosure above has been translated to U.S. Dollar, from Euro, using the period end exchange rate of €1.00 to $1.08.

Net Loss per Ordinary Share (Tables)

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Securities Excluded in the Computation of Diluted Net Loss Per Ordinary Share

The following securities, presented based on amounts outstanding at each period end, are considered to be ordinary share equivalents, but were excluded from the computation of diluted net loss per ordinary share because to do so would have been anti-dilutive:


	June 30,
	2023		2022
Share options		17,034,942		13,894,428
Unvested restricted share units		3,191,423		500,989
Ordinary shares to be issued upon exercise of warrants (1)		109,083,590		—
		129,309,955		14,395,417

(1) The warrants included in the table are exercisable subject to future contingencies (See Note 12)

Prepaid Expenses and Other Current Assets (Tables)

6 Months Ended

Jun. 30, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):


	June 30,		December 31,
	2023		2022
Prepaid external research and development expenses	$	378	$	881
Other prepayments		2,998		1,817
VAT receivable		712		1,077
Non-trade receivables		419		1,851
Rent deposits		1,033		960
Total prepaid expenses and other current assets	$	5,540	$	6,586

Share-based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of share options granted				$ 2.81	$ 0.32
Total intrinsic value of share options exercised		$ 100		$ 100
Number of shares granted				1,700,200
Stock compensation expense		2,578	$ 3,956	$ 6,090	$ 8,616
RSUs vested				609,170
Total unrecognized compensation cost of stock option and time-based RSUs		10,400		$ 10,400
Compensation cost expected to be recognized weighted average period				2 years 7 months 2 days
Total unrecognized compensation cost of performance-based RSUs		$ 500		$ 500
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining shares available for issuance		12,421,580		12,421,580
Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining shares available for issuance		730,500		730,500
2018 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining shares available for issuance		1,460,590		1,460,590
Performance-based Restricted Share Units ("RSUs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation cost expected to be recognized weighted average period				6 months
Total unrecognized compensation cost of performance-based RSUs		$ 100		$ 100
Time-based Restricted Share Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted				1,700,200
RSUs vested				609,170
Award vesting period				3 years
Total unrecognized compensation cost of stock option and time-based RSUs		1,100		$ 1,100
Compensation cost expected to be recognized weighted average period				2 years 1 month 9 days
Chief Executive Officer \| Performance-based Restricted Share Units ("RSUs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted	195,000
Total grant date fair value	$ 1,400
Vesting rights				In April 2020, the Company granted 195,000 performance-based restricted share units (“RSUs”) with a total grant date fair value of $1.4 million to its Chief Executive Officer, Bobby Gaspar, M.D., Ph.D. Dr. Gaspar earns one-third of the award for each of the first three to occur of four milestones (65,000 RSUs are earned for each achieved milestone). The milestones relate to specific clinical and regulatory goals which have to be achieved before December 31, 2023 in order for the underlying RSUs to be eligible to vest.
Achievement of at Least Three of Four Milestones
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs vested				65,000
Achievement of Two Milestones
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock compensation expense		$ 100		$ 800

Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Schedule of Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents, and restricted cash were comprised of the following (in thousands):


	As of June 30,		As of December 31,
	2023		2022
Cash and cash equivalents	$	38,273	$	68,424
Restricted cash		4,215		4,215
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$	42,488	$	72,639

Notes Payable (Tables)

6 Months Ended

Jun. 30, 2023

Debt Disclosure [Abstract]

Summary of Notes Payable

Notes payable consist of the following (in thousands):


	June 30,			December 31,
	2023			2022
Notes payable, net of issuance costs	$	27,297		$	31,970
Less: current portion		(9,429	)		(9,429	)
Notes payable, net of current portion		17,868			22,541
Accretion related to final payment		572			450
Notes payable, long term	$	18,440		$	22,991

Summary of Estimated Future Principal Payments Due

As of June 30, 2023, the estimated future principal payments due are as follows (in thousands):


	Aggregate Minimum Payments
2023 (remaining six months)	$	4,714
2024		9,429
2025		9,429
2026		5,084
Total		28,656
Less current portion		(9,429	)
Less unamortized portion of final payment		(584	)
Less unamortized debt issuance costs		(203	)
Notes payable, long term	$	18,440

Commitments and Contingencies - Schedule of Annual Commitments Associated with the Contract (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Other Commitments [Line Items]
2023 (remaining six months)	$ 4,212
2024	10,593
2025	5,297
Total manufacturing commitments	20,102
Product Manufacturing Commitments
Other Commitments [Line Items]
2023 (remaining six months)	976
2024	1,952
2025	976
Total manufacturing commitments	3,904
Dedicated Manufacturing And Development Resources
Other Commitments [Line Items]
2023 (remaining six months)	3,236
2024	6,472
2025	3,236
Total manufacturing commitments	12,944
Exclusive Transduction Suites
Other Commitments [Line Items]
2024	2,169
2025	1,085
Total manufacturing commitments	$ 3,254

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 38,273	$ 68,424
Marketable securities	112,468	75,326
Accounts receivable	9,547	8,467
Inventory	6,937	3,400
Prepaid expenses and other current assets	5,540	6,586
Research and development tax credit receivable	8,525	5,942
Total current assets	181,290	168,145
Non-current assets:
Operating lease right-of-use-assets	21,018	22,774
Property and equipment, net	7,808	8,138
Research and development tax credit receivable	2,101
Restricted cash	4,215	4,215
Intangible assets, net	3,474	3,560
Other assets	12,396	12,075
Total non-current assets	51,012	50,762
Total assets	232,302	218,907
Current liabilities:
Accounts payable	6,950	9,318
Accrued expenses and other current liabilities	33,786	34,437
Deferred revenue, current	752	959
Operating lease liabilities	6,600	6,424
Notes payable, current	9,429	9,429
Total current liabilities	57,517	60,567
Notes payable, long-term	18,440	22,991
Deferred revenue, net of current portion	10,819	10,315
Operating lease liabilities, net of current portion	16,044	19,246
PIPE Warrant liabilities	12,266
Other long-term liabilities	8,169	7,524
Total liabilities	123,255	120,643
Commitments and contingencies (see Note 15)
Shareholders’ equity:
Ordinary shares (voting and non-voting), GBP 0.10 par value; Most recent authority to allot up to a maximum nominal value of GBP 33,556,809 and GBP 13,023,851.50 of shares at June 30, 2023 and December 31, 2022, respectively; Issued and outstanding - 227,215,699 and 126,947,225 shares at June 30, 2022 and December 31, 2022, respectively.	29,456	16,419
Additional paid-in capital	991,642	956,711
Accumulated other comprehensive income	18,552	26,018
Accumulated deficit	(930,603)	(900,884)
Total shareholders’ equity	109,047	98,264
Total liabilities and shareholders’ equity	$ 232,302	$ 218,907

Research and Development Tax Credit Receivable

6 Months Ended

Jun. 30, 2023

Research and Development Tax Credit Receivable [Abstract]

Research and Development Tax Credit Receivable

6. Research and development tax credit receivable


	Three Months Ended					Six Months Ended
	2023		2022			2023		2022
Balance at beginning of period	$	6,844	$	16,649		$	5,942	$	30,723
Recognition of credit claims as offset to research and development expense		3,602		1,764			4,371		5,101
Receipt of credit claims		—		(1,916	)		-		(18,390	)
Foreign currency translation		180		(1,321	)		313		(2,258	)
Balance at end of period	$	10,626	$	15,176		$	10,626	$	15,176

The Company's tax incentive receivable from the UK government was approximately $10.6 million as of the June 30, 2023. During the three months ended June 30, 2023, the Company recorded $2.3 million of additional tax credits related to a change in estimate associated with its U.K. research and development tax credit receivable claim for fiscal year 2022 ($8.5 million) and estimate of its 2023 claim through June 30, 2023 ($2.1 million). The change in estimate was based on the results of a tax credit analysis associated with the

Company’s qualified projects and research and development expenditures completed during the quarter to finalize the 2022 U.K. tax return. This amount was recorded as an offset to research and development expense.

Inventory - Additional Information (Details) $ in Millions	Jun. 30, 2023 USD ($)
Inventory Disclosure [Abstract]
Inventory capitalized	$ 4.8

Intangible Assets, Net - Schedule of Estimated Future Amortization For Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
2023 (remaining six months)	$ 171
2024	342
2025	342
2026	342
2027	342
Thereafter	1,935
Intangible Assets, Net	$ 3,474	$ 3,560

Share-based Compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation	$ 2,578	$ 3,956	$ 6,090	$ 8,616
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation	1,025	1,744	2,261	3,706
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation	1,553	2,212	3,829	4,910
Share Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation	2,253	3,774	4,808	8,282
Restricted Share Units
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation	$ 325	$ 182	$ 1,282	$ 334

Restructuring Charges

6 Months Ended

Jun. 30, 2023

Restructuring and Related Activities [Abstract]

Restructuring Charges

. Restructuring charges

On March 30, 2022, the Company announced its commitment to focus on severe neurometabolic diseases and early research programs, and to discontinue its investment in and seek strategic alternatives for the Company’s programs in rare primary immune deficiencies, including OTL-103 for treatment of Wiskott Aldrich syndrome (“WAS”), OTL-102 for treatment of X-linked chronic granulomatous disease (“X-CGD”), and Strimvelis for adenosine deaminase severe combined immunodeficiency (“ADA-SCID”). The Company recognized a one-time charge in the first six months of 2022 of approximately $1.9 million, which relates to employee-related termination costs. For the six months ended June 30, 2022, approximately $1.6 million and $0.4 million is recognized in research and development expenses and selling, general, and administrative expenses, respectively, on the Company's unaudited condensed consolidated statements of operations and comprehensive loss. The restructuring charge was included in accrued expenses and other current liabilities in the Company’s unaudited condensed consolidated balance sheets.

Activity for the six months ended June 30, 2022, is summarized as follows (in thousands):


	Three Months Ended June 30, 2022			Six Months Ended June 30, 2022
Balance at beginning of period	$	2,481		$	6
Charged to expense		-			2,481
Non-cash adjustments and foreign currency translation		(554	)		(554	)
Payments made		(1,089	)		(1,095	)
Balance at end of period	$	838		$	838

There was no restructuring activity in the six months ended June 30, 2023.

Shareholders' Equity - Additional Information (Details) - GBP (£)	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Jun. 16, 2021
Class of Stock [Line Items]
Percentage rate of excess ordinary shares	19.99%
Ordinary shares, authorized	£ 33,556,809	£ 13,023,851.5
Ordinary shares, issued	227,215,699	126,947,225
Ordinary shares, outstanding	227,215,699	126,947,225
PIPE Authority
Class of Stock [Line Items]
Ordinary shares, authorized	£ 15,158,359
Remaining ordinary shares	10,908,359
General Authority
Class of Stock [Line Items]
Ordinary shares, authorized	18,398,450
Remaining ordinary shares	£ 23,924,545.7
2021 Authority
Class of Stock [Line Items]
Ordinary shares, authorized			£ 13,023,851.5
Remaining ordinary shares			£ 5,526,095.7
Ordinary Shares
Class of Stock [Line Items]
Ordinary shares, issued	185,602,299
Ordinary shares, outstanding	185,602,299
Number of deferred share	1
Nominal value of deferred share	£ 4.89687
Non-voting Ordinary Shares
Class of Stock [Line Items]
Ordinary shares, issued	41,613,400
Ordinary shares, outstanding	41,613,400

Fair Value Measurements and Marketable Securities - Schedule of Significant Unobservable Inputs used in Valuation Model to Measure PIPE Warrants and PIPE Units Liabilities (Details)	Jun. 30, 2023 $ / shares	Jun. 22, 2023 $ / shares
PIPE Units Liability \| Implied Probabilities of Occurrence of Second Closing and FDA Approval
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input	0.305
PIPE Units Liability \| Discount for Lack of Marketability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input	0.05
PIPE Units Liability \| Expected Warrant Exercise Date July 30, 2024 \| Anticipated Common Stock Price (at Exercise Date)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input, stock price		$ 10.4
PIPE Units Liability \| Expected Warrant Exercise Date July 30, 2024 \| Expected Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input, term		1 year 1 month 9 days
PIPE Units Liability \| Expected Warrant Exercise Date July 30, 2024 \| Expected Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input		0.75
PIPE Units Liability \| Expected Warrant Exercise Date April 30, 2025 \| Anticipated Common Stock Price (at Exercise Date)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input, stock price		$ 10.07
PIPE Units Liability \| Expected Warrant Exercise Date April 30, 2025 \| Expected Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input, term		1 year 10 months 9 days
PIPE Units Liability \| Expected Warrant Exercise Date April 30, 2025 \| Expected Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input		0.748
PIPE Warrant Liability \| Implied Probabilities of Occurrence of Second Closing and FDA Approval
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input	0.346
PIPE Warrant Liability \| Discount for Lack of Marketability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Units measurement input	0
PIPE Warrant Liability \| Expected Warrant Exercise Date July 30, 2024 \| Anticipated Common Stock Price (at Exercise Date)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input, stock price	$ 10.39
PIPE Warrant Liability \| Expected Warrant Exercise Date July 30, 2024 \| Expected Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input, term	1 year 29 days
PIPE Warrant Liability \| Expected Warrant Exercise Date July 30, 2024 \| Expected Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.756
PIPE Warrant Liability \| Expected Warrant Exercise Date April 30, 2025 \| Anticipated Common Stock Price (at Exercise Date)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input, stock price	$ 10.07
PIPE Warrant Liability \| Expected Warrant Exercise Date April 30, 2025 \| Expected Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input, term	1 year 10 months 2 days
PIPE Warrant Liability \| Expected Warrant Exercise Date April 30, 2025 \| Expected Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.745

Net Loss per Ordinary Share - Securities Excluded in the Computation of Diluted Net Loss Per Ordinary Share (Details) - shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares attributable to anti-dilutive shares	129,309,955	14,395,417
Share Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares attributable to anti-dilutive shares	17,034,942	13,894,428
Unvested Restricted Shares Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares attributable to anti-dilutive shares	3,191,423	500,989
Ordinary Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares attributable to anti-dilutive shares	109,083,590

Fair Value Measurements and Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]

Schedule of Cash Equivalents and Marketable Securities


	Fair Value Measurements as of June 30, 2023
	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents
Money market funds	$	3,305	$	—	$	—	$	3,305
U.S. treasuries		—		1,995		—		1,995
Commercial paper		—		6,989		—		6,989
Total cash equivalents	$	3,305	$	8,984	$	—	$	12,289
Marketable securities
U.S. government securities	$	—	$	12,326	$	—	$	12,326
U.S. treasuries		—		14,277		—		14,277
Corporate bonds		—		16,118		—		16,118
Commercial paper		—		69,747		—		69,747
Total marketable securities	$	—	$	112,468	$	—	$	112,468
Total Assets	$	3,305	$	121,452	$	—	$	124,757

Liabilities
PIPE Warrant liability	$	—	$	—	$	12,266	$	12,266
Total Liabilities	$	—	$	—	$	12,266	$	12,266


	Fair Value Measurements as of December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets
Cash equivalents
Money market funds	$	1,239	$	—	$	—	$	1,239
U.S. treasuries		—		6,600		—		6,600
U.S. government securities		—		5,200		—		5,200
Commercial paper		—		14,122		—		14,122
Total cash equivalents	$	1,239	$	25,922	$	—	$	27,161
Marketable securities
U.S. government securities	$	—	$	1,984	$	—	$	1,984
Corporate bonds		—		25,475		—		25,475
Commercial paper		—		47,867		—		47,867
Total marketable securities	$	—	$	75,326	$	—	$	75,326
Total Assets	$	1,239	$	101,248	$	—	$	102,487

Schedule of Significant Unobservable Inputs used in Valuation Model to Measure PIPE Warrants and PIPE Units Liabilities

The significant unobservable inputs used in the valuation models during the three months ended June 30, 2023, to measure the fair value of the PIPE Warrants and PIPE Units are as follows:


	PIPE Unit Liability		PIPE Warrant Liability
Valuation date	June 22, 2023		June 30, 2023
Expected warrant exercise date	July 30, 2024	April 30, 2025	July 30, 2024	April 30, 2025
Black-Scholes inputs
Anticipated common stock price (at exercise date)	$10.40	$10.07	$10.39	$10.07
Expected term (in years)	1.11	1.86	1.08	1.84
Expected volatility	75.0%	74.8%	75.6%	74.5%

Other significant unobservable inputs
Implied probabilities of occurrence of Second Closing and FDA Approval	30.5%		34.6%
Discount for lack of marketability	5.0%		0%

Schedule of Aggregate Fair Values of PIPE Warrant Liability and PIPE Unit Liability


	PIPE Warrant Liability		PIPE Unit Liability
Balance at December 31, 2022	$	—	$	—
Issuances during period		11,098		25
Change in fair value		1,168		(9,668	)
Settlement of PIPE Unit liability upon Second Closing		—		9,643
Balance at June 30, 2023	$	12,266	$	-

Schedule of Amortized Cost and Fair Value of Available-for-Sale Marketable Debt Securities

The following tables summarize the amortized cost and fair value of the Company's available-for-sale marketable debt securities (in thousands):


	June 30, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
U.S. government securities	$	12,338	$	1	$	(13	)	$	—	$	12,326
U.S. treasuries		16,280		—		(8	)		—	$	16,272
Corporate bonds		16,232		—		(114	)		—		16,118
Commercial paper		76,801		—		(65	)		—		76,736
Total	$	121,651	$	1	$	(200	)	$	—	$	121,452


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
U.S. government securities	$	7,188	$	1	$	(6	)	$	—	$	7,183
U.S. treasuries		6,599		1		—			—	$	6,600
Corporate bonds		25,656		—		(180	)		—	$	25,476
Commercial paper		62,038		3		(52	)		—		61,989
Total	$	101,481	$	5	$	(238	)	$	—	$	101,248

Schedule of Debt Securities by Contractual Maturity

The following table summarizes the Company’s debt securities by contractual maturity, as of June 30, 2023, and December 31, 2022 (in thousands):


	June 30, 2023		December 31, 2022
Maturities in one year or less	$	117,460	$	98,277
Maturities between one and three years		3,992		2,971
Total	$	121,452	$	101,248

Fair Value Measurements and Marketable Securities - Schedule of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cash equivalents
Total cash equivalents	$ 12,289	$ 27,161
Marketable securities
Total marketable securities	112,468	75,326
Total	124,757	102,487
Liabilities
Total Liabilities	12,266
Level 1
Cash equivalents
Total cash equivalents	3,305	1,239
Marketable securities
Total	3,305	1,239
Level 2
Cash equivalents
Total cash equivalents	8,984	25,922
Marketable securities
Total marketable securities	112,468	75,326
Total	121,452	101,248
Level 3
Liabilities
Total Liabilities	12,266
PIPE Warrant Liability
Liabilities
Total Liabilities	12,266
PIPE Warrant Liability \| Level 3
Liabilities
Total Liabilities	12,266
Money Market Funds
Cash equivalents
Total cash equivalents	3,305	1,239
Money Market Funds \| Level 1
Cash equivalents
Total cash equivalents	3,305	1,239
U.S. Treasuries
Cash equivalents
Total cash equivalents	1,995	6,600
Marketable securities
Total marketable securities	14,277
U.S. Treasuries \| Level 2
Cash equivalents
Total cash equivalents	1,995	6,600
Marketable securities
Total marketable securities	14,277
U.S. Government Securities
Cash equivalents
Total cash equivalents		5,200
Marketable securities
Total marketable securities	12,326	1,984
U.S. Government Securities \| Level 2
Cash equivalents
Total cash equivalents		5,200
Marketable securities
Total marketable securities	12,326	1,984
Corporate Bonds
Marketable securities
Total marketable securities	16,118	25,475
Corporate Bonds \| Level 2
Marketable securities
Total marketable securities	16,118	25,475
Commercial Paper
Cash equivalents
Total cash equivalents	6,989	14,122
Marketable securities
Total marketable securities	69,747	47,867
Commercial Paper \| Level 2
Cash equivalents
Total cash equivalents	6,989	14,122
Marketable securities
Total marketable securities	$ 69,747	$ 47,867

Accrued Expenses and Other Current Liabilities

6 Months Ended

Jun. 30, 2023

Accrued Liabilities and Other Liabilities [Abstract]

Accrued Expenses and Other Current Liabilities

8. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30,		December 31,
	2023		2022
Accrued external research and development expenses	$	10,985	$	11,230
Accrued payroll and related expenses		9,132		12,312
Accrued professional fees		2,588		2,263
Accrued other		3,459		2,647
Accrued governmental rebates		4,005		2,300
Strimvelis liability - current portion		3,617		3,685
Total accrued expenses and other current liabilities	$	33,786	$	34,437

Fair Value Measurements and Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Jun. 22, 2023	Mar. 10, 2023	Mar. 06, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets transfers between level 1 and level 2	$ 0	$ 0				$ 0
Warrants to purchase ordinary shares			46,750,000	62,333,590
Realized gains or losses recognized on investments	$ 0	$ 0
Securities Purchase Agreement \| 2023 Private Placement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants to purchase ordinary shares					109,083,590
Securities Purchase Agreement \| 2023 Private Placement \| Initial Closing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants to purchase ordinary shares				62,333,590

Restructuring Charges (Tables)

6 Months Ended

Jun. 30, 2023

Restructuring and Related Activities [Abstract]

Summary of Restructuring Charges

Activity for the six months ended June 30, 2022, is summarized as follows (in thousands):


	Three Months Ended June 30, 2022			Six Months Ended June 30, 2022
Balance at beginning of period	$	2,481		$	6
Charged to expense		-			2,481
Non-cash adjustments and foreign currency translation		(554	)		(554	)
Payments made		(1,089	)		(1,095	)
Balance at end of period	$	838		$	838

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

The Company's significant accounting policies are disclosed in the audited consolidated financial statements for the year ended December 31, 2022, and notes thereto, which are included in the Company's Annual Report on Form 10-K filed with the SEC on March 14, 2023 (the “Annual Report”). Since the date of those financial statements there have been no material changes to the Company's significant accounting policies other than those discussed below.

Basis of presentation

These condensed consolidated financial statements of the Company are unaudited and have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial reporting and in accordance with Regulation S-X, Rule 10-01. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”), and Accounting Standards Update (“ASU”), of the Financial Accounting Standards Board (“FASB”).

These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes included in the Company’s Annual Report. The condensed consolidated balance sheet as of December 31, 2022, was derived from audited consolidated financial statements included in the Company’s Annual Report but does not include all disclosures required by GAAP.

Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from these interim financial statements. However, these interim financial statements include all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of the Company’s management, necessary to fairly state the results of the interim period. The interim results are not necessarily indicative of results to be expected for the full year.

Amounts reported are presented in thousands, except percentages, per share amounts or as otherwise noted. As a result, certain totals may not sum due to rounding.

Principles of consolidation

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Use of estimates

The preparation of unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. Significant estimates and assumptions reflected in these unaudited condensed consolidated financial statements include, but are not limited to, the accrual for research and development expenses, the research and development tax credit receivable, share-based compensation, collaboration agreement milestones, variable consideration in revenue recognition, operating lease assets and liabilities, valuation of PIPE Warrants and PIPE Units, and income taxes. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Foreign currency

The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. Dollar are translated into U.S. Dollars using period-end exchange rates for assets and liabilities, historical exchange rates for shareholders’ equity and weighted average exchange rates for operating results. Unrealized losses are driven primarily by intercompany balances denominated in currencies other than the functional currency of the entity with the intercompany balance, and typically fluctuates concurrently with fluctuations in the U.S. Dollar, Pounds sterling, and Euro exchange rates. Translation gains and losses are included in accumulated other comprehensive income (loss) in shareholders’ equity. Foreign currency transaction gains and losses are included in other income (expense), net in the results of operations. The Company recorded realized and unrealized foreign currency transaction losses of $7.5 million for the six months ended June 30, 2023, and realized and unrealized foreign currency transaction losses of $24.3 million for the six months ended June 30, 2022, which is included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss.

Accounts receivable

Accounts receivable arise from product revenue and amounts due from the Company's collaboration partners and have payment terms that generally require payment within 30 to 90 days. For some Libmeldy customers, our payment terms can range from 30 days to under one year. The amount from product revenue represents amounts due from distributors in Europe, which are recorded net of reserves for trade discounts and allowances, and other incentives to the extent such amounts are payable to the customer by the Company. The Company monitors economic conditions to identify facts or circumstances that may indicate that its receivables are at risk of collection. The Company provides reserves against accounts receivable for estimated losses, if any, that may result from a customer's inability to pay based on the composition of its accounts receivable, current economic conditions, and historical credit loss activity. Amounts determined to be uncollectible are charged or written-off against the reserve. During the three and six months ended June 30, 2023, the Company did not record any expected credit losses related to outstanding accounts receivable.

Restricted cash

Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements are recorded as restricted cash on the Company’s condensed consolidated balance sheets. The Company has an outstanding letter of credit for $3.0 million associated with a lease and is required to hold this amount in a standalone bank account, as of June 30, 2023, and December 31, 2022. The Company is also contractually required to maintain cash collateral accounts associated with corporate credit cards and other leases in the amount of $1.3 million at June 30, 2023 and December 31, 2022.

Cash, cash equivalents, and restricted cash were comprised of the following (in thousands):


	As of June 30,		As of December 31,
	2023		2022
Cash and cash equivalents	$	38,273	$	68,424
Restricted cash		4,215		4,215
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$	42,488	$	72,639

Recently adopted accounting pronouncements

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting and issued two subsequent amendments: ASU 2021-01, issued in January 2021, refines the scope of ASU and clarifies some of its guidance as part of the FASB’s monitoring of global reference rate reform activities and ASU 2022-06, issued in December 2022, which extends the effective period of the ASU through December 31, 2023 (collectively, including ASU 2020-04, “ASC 848”). ASC 848 provides temporary optional expedients and exceptions to the GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. ASC 848 is effective for all entities as of March 12, 2020, through December 31, 2024, at which time transition is expected to be complete. The Company adopted this standard as of January 1, 2023. The application of this ASU did not have a material impact on the Company's financial position, results of operations, or cash flows.

Product Revenue, Net

6 Months Ended

Jun. 30, 2023

Revenue from Contract with Customer [Abstract]

Product Revenue, Net

14. Product revenue, net

The following table presents the Company's net revenue by product (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Libmeldy	$	6,651	$	3,145	$	7,185	$	8,204
Strimvelis		—		636		—		636
Total	$	6,651	$	3,781	$	7,185	$	8,840

Activity in each of the product revenue allowance and reserve categories for Libmeldy is summarized as follows (in thousands):


	Trade discounts and allowances			Government rebates		Total
Balance as of December 31, 2022	$	4,390		$	2,300	$	6,690
Provision Related to sales in the current year		3,950			1,655		5,605
Credits and payments made during the period		(7,344	)		—		(7,344	)
Foreign currency translation		—			50		50
Balance as of June 30, 2023	$	996		$	4,005	$	5,001

The total reserves described above are summarized as components of the Company's condensed consolidated balance sheets as follows (in thousands):


	As of June 30, 2023		As of December 31, 2022
Reduction of accounts receivable, net	$	996	$	4,390
Component of accrued expenses and other current liabilities		4,005		2,300
Total revenue-related reserves	$	5,001	$	6,690

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-15

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-13

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Option Activity

The following table summarizes option activity for ordinary shares under the plans for the six months ended June 30, 2023:


	Shares			Weighted Average Exercise Price per Ordinary Share
Outstanding at December 31, 2022		16,424,167		$	1.56
Granted		5,085,330			0.49
Exercised		(332,180	)		0.12
Forfeited		(795,167	)		4.27
Outstanding at June 30, 2023		20,382,150		$	1.21
Vested and expected to vest at June 30, 2023		20,382,150		$	1.21
Exercisable at June 30, 2023		10,452,810		$	1.82

Summary of Award Activity

The following table summarizes award activity for the six months ended June 30, 2023:


	Performance-based RSUs		Time-based RSUs			Total RSUs			Weighted Average Grant Date Fair Value per Share
Unvested at December 31, 2022		195,000		1,868,876			2,063,876		$	0.55
Granted		—		1,700,200			1,700,200			0.46
Vested		—		(609,170	)		(609,170	)		0.52
Forfeited		—		(152,806	)		(152,806	)		0.46
Unvested at June 30, 2023		195,000		2,807,100			3,002,100		$	0.51

Share-based Compensation Expense


	Three Months Ended				Six Months Ended
	2023		2022		2023		2022
Research and development	$	1,025	$	1,744	$	2,261	$	3,706
Selling, general and administrative		1,553		2,212		3,829		4,910
Total	$	2,578	$	3,956	$	6,090	$	8,616

Total share-based compensation by award type was as follows (in thousands):


	Three Months Ended				Six Months Ended
	2023		2022		2023		2022
Share options	$	2,253	$	3,774	$	4,808	$	8,282
Restricted share units		325		182		1,282		334
Total	$	2,578	$	3,956	$	6,090	$	8,616

Share-based Compensation - Summary of Award Activity (Details)	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs, Unvested at December 31, 2022	2,063,876
RSUs, Granted	1,700,200
RSUs, Vested	(609,170)
RSUs, Forfeited	(152,806)
RSUs, Unvested at June 30, 2023	3,002,100
Weighted Average Grant Date Fair Value per Share, Unvested at December 31, 2022 \| $ / shares	$ 0.55
Weighted Average Grant Date Fair Value per Share, Granted \| $ / shares	0.46
Weighted Average Grant Date Fair Value per Share, Vested \| $ / shares	0.52
Weighted Average Grant Date Fair Value per Share, Forfeited \| $ / shares	0.46
Weighted Average Grant Date Fair Value per Share, Unvested at June 30, 2023 \| $ / shares	$ 0.51
Performance-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs, Unvested at December 31, 2022	195,000
RSUs, Unvested at June 30, 2023	195,000
Time-based RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs, Unvested at December 31, 2022	1,868,876
RSUs, Granted	1,700,200
RSUs, Vested	(609,170)
RSUs, Forfeited	(152,806)
RSUs, Unvested at June 30, 2023	2,807,100

Private Placement Transaction

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Private placement transaction

12. Private placement transaction

On March 6, 2023, the Company entered into the SPA with several investors, pursuant to which the Company agreed to sell, in an unregistered offering (the “2023 Private Placement”), up to an aggregate of (i) 99,166,900 ordinary shares and non-voting ordinary shares, nominal value £0.10 per share (collectively, the “Shares”) and (ii) warrants to purchase an aggregate of 109,083,590 Shares. The 2023 Private Placement consisted of two closings, referred to herein as the "First Closing" and "Second Closing". At each closing, the Shares were sold in fixed combinations with the warrants as units, with each unit consisting of 10 Shares and 1 accompanying warrant to purchase 11 shares. The warrants are contingently exercisable for 30 days following (i) the Company’s public announcement of its receipt of marketing approval of its biologics license application (“BLA”) submitted to the FDA with respect to OTL-200 (the “Vesting Event”) and (ii) receipt of shareholder approval to increase the number of authorized shares. Each warrant will have an exercise price equal to $1.10 per share in the event the Vesting Event occurs on or prior to December 31, 2024, and $0.95 per share in the event the Vesting Event occurs after December 31, 2024. The warrants will expire at the conclusion of the 30-day exercise period or on March 10, 2026, whichever is earlier. Each warrant holder has the option, in their sole discretion, to exercise the warrants for either ordinary shares or non-voting ordinary shares.

On March 10, 2023, the Company completed the First Closing and issued and sold (i) 40,053,500 ordinary shares, (ii) 16,613,400 non-voting ordinary shares, and (iii) warrants to purchase an aggregate of 62,333,590 ordinary shares or non-voting ordinary shares, at a purchase price of $6.00 per unit, generating gross proceeds of $34.0 million, before deducting offering expenses of $0.9 million payable by the Company.

On June 22, 2023, the Company completed the Second Closing and issued and sold (i) 13,408,074 ordinary shares, (ii) 29,091,926 non-voting ordinary shares, and (iii) warrants to purchase an aggregate of 46,750,000 ordinary shares or non-voting ordinary shares, at a purchase price of $8.00 per unit (collectively, the “PIPE Units”). The Second Closing was contingent upon (x) the Company’s announcement of its intention to file a BLA submission following receipt of the minutes from the U.S. Food and Drug Administration (“FDA”) in connection with the Company’s pre-BLA meeting for OTL-200, provided such minutes do not expressly advise the Company not to proceed with a BLA submission, and (y) shareholder approval to increase the number of authorized shares.

The Company generated gross proceeds of $34 million from the Second Closing before deducting offering expenses of $1.2 million payable by the Company. The warrants issued in the First closing and the Second Closing of the 2023 Private Placement are referred to collectively herein as the “PIPE Warrants”.

Accounting Analysis

Upon execution of the SPA on March 6, 2023, the Company determined that each of the instruments to be issued in the First Closing and Second Closing did not meet the criteria for equity classification as they were not considered indexed to the Company’s stock. The Company recorded these instruments at a fair value of $34.0 million, which was comprised of $27.5 million, $6.4 million, and $0.02 million allocated to the Shares, PIPE Warrants, and PIPE Units, respectively. The Company incurred issuance costs of $0.5 million in connection with executing the SPA, which were expensed upon execution within other income (expense) on the unaudited condensed consolidated statements of operations and comprehensive loss.

Upon the First Closing on March 10, 2023, the Company determined that the ordinary shares met the criteria for equity classification. The PIPE Warrants issued in the First Closing and the PIPE Units that were issued in the Second Closing did not meet the criteria for equity classification due to the lack of sufficient authorized and unissued shares and the price adjustment feature depending on the timing of the occurrence of a Vesting Event. The Company reclassified the ordinary shares to equity and recorded a mark-to-market adjustment of a $3.6 million gain, which represents the change in fair value of the ordinary shares between March 6, 2023, and March 10, 2023. As a result of the First Closing, the Company recorded $24.0 million to equity. The Company incurred issuance costs of $1.1 million which were contingent on the closing of the SPA. These issuance costs were allocated between the ordinary shares, PIPE Warrants, and PIPE Units, on a relative fair value basis. Issuance costs of $0.9 million allocated to the ordinary shares were recognized as a discount to the ordinary shares recorded in permanent equity. Issuance costs of $0.2 million allocated to the PIPE Warrants and PIPE Units were expensed within other income (expense) on the unaudited condensed consolidated statement of operations and comprehensive loss.

Upon the Second Closing on June 22, 2023, the PIPE Units were settled. The Company recognized a final fair value adjustment to the PIPE Units immediately prior to the Second Closing. The fair value adjustment was a $9.7 million gain. Upon issuance of the shares and warrants under the Second Closing, the Company recorded $19.7 million to equity, recorded $4.6 million to the PIPE Warrants liability, and derecognized the PIPE Units asset of $9.6 million. The Company incurred issuance costs of $1.2 million. These issuance costs were allocated between the ordinary shares and the PIPE Warrants on a relative fair value basis. Issuance costs of $1.0 million allocated to the ordinary shares were recognized as a discount to the ordinary shares recorded in permanent equity. Issuance costs of $0.2 million allocated to the PIPE Warrants were expensed within other income (expense) on the unaudited condensed consolidated statement of operations and comprehensive loss.

The PIPE Warrants are classified within non-current liabilities on the unaudited condensed consolidated balance sheets as of June 30, 2023, and will be adjusted to fair value at each subsequent balance sheet date until the warrants are reclassified to equity or settled. Changes in the fair value of the PIPE Warrants are recognized as a component of other income (expense) in the unaudited condensed consolidated statement of operations and comprehensive loss. For the three and six months ended June 30, 2023, the Company

recognized changes in fair value resulting in a loss of $1.4 million and $1.2 million, respectively, related to the PIPE Warrants. As of June 30, 2023, warrants to purchase an aggregate of 109,083,590 ordinary shares or non-voting ordinary shares were issued and outstanding, and none were exercisable.

The PIPE Units are no longer outstanding as of June 30, 2023. Changes in the fair value of the PIPE Units were recognized as a component of other income (expense), net in the unaudited condensed consolidated statement of operations and comprehensive loss. For the three and six months ended June 30, 2023, the Company recognized changes in fair value resulting in a gain of $9.7 million and $9.6 million, respectively, related to the PIPE Units.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2023

Accounting Policies [Abstract]

Basis of presentation

Amounts reported are presented in thousands, except percentages, per share amounts or as otherwise noted. As a result, certain totals may not sum due to rounding.

Principles of consolidation

Cash, cash equivalents, and restricted cash were comprised of the following (in thousands):


	As of June 30,		As of December 31,
	2023		2022
Cash and cash equivalents	$	38,273	$	68,424
Restricted cash		4,215		4,215
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$	42,488	$	72,639

Recently adopted accounting pronouncements

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss attributable to ordinary shareholders	$ (29,719)	$ (95,212)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,298	1,366
Share-based compensation	6,090	8,616
Non-cash interest expense	182	186
Amortization of provision on loss contract		(276)
Amortization of premium on marketable securities	(1,553)	189
Deferred income taxes	448
Change in fair value of warrant and tranche obligation liabilities	(12,057)
Unrealized foreign currency and other non-cash adjustments	(9,767)	25,092
Changes in operating assets and liabilities:
Accounts receivable	(693)	(2,997)
Inventory	(3,316)	(114)
Research and development tax credit receivable	(4,371)	13,289
Prepaid expenses, other current assets and other assets	439	883
Operating leases, right-of-use assets	2,234	2,777
Accounts payable, accrued expenses and other liabilities	(2,897)	4,251
Deferred revenue	(193)	(138)
Operating lease liabilities	(3,466)	(3,887)
Net cash used in operating activities	(57,341)	(45,975)
Cash flows from investing activities:
Proceeds from sales and maturities of marketable securities	79,000	97,214
Purchases of marketable securities	(114,556)	(50,891)
Purchases of property and equipment	(483)	(1,572)
Net cash provided by (used in) investing activities	(36,039)	44,751
Cash flows from financing activities:
Proceeds from employee equity plans, net of taxes withheld	210	137
Payment of taxes on restricted stock vesting	(166)
Proceeds from the issuance of units in private placement	68,000
Payment of placement agent fees and offering costs in connection with private placement	(889)
Repayment of notes payable	(4,714)
Net cash provided by financing activities	62,441	137
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	788	(1,355)
Net decrease in cash, cash equivalents and restricted cash	(30,151)	(2,442)
Cash, cash equivalents, and restricted cash, beginning of period	72,639	60,178
Cash, cash equivalents, and restricted cash, end of period	42,488	57,736
Supplemental disclosure of noncash activities
Private placement offering costs in accounts payable and accrued expenses	954
Property and equipment in accounts payable and accrued expenses		1,046
Supplemental disclosure of cash flow information:
Lease assets obtained in exchange for new operating lease liabilities, net		4,912
Non-cash adjustments to operating lease right-of-use assets and liabilities		530
Cash paid for interest	$ 1,593	$ 1,153

Restructuring Charges - Summary of Restructuring Charges (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Restructuring and Related Activities [Abstract]
Balance at beginning of period	$ 2,481,000		$ 6,000
Charged to expense		$ 0	2,481,000
Non-cash adjustments and foreign currency translation	(554,000)		(554,000)
Payments made	(1,089,000)		(1,095,000)
Balance at end of period	$ 838,000		$ 838,000

Net loss per ordinary share

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Net Loss per Ordinary Share

18. Net loss per ordinary share

The Company is in a loss position for all periods presented. As such, the basic net loss per ordinary share is the same as the diluted net loss per ordinary share as the inclusion of all potential ordinary share equivalents outstanding would have been anti-dilutive.


	June 30,
	2023		2022
Share options		17,034,942		13,894,428
Unvested restricted share units		3,191,423		500,989
Ordinary shares to be issued upon exercise of warrants (1)		109,083,590		—
		129,309,955		14,395,417

(1) The warrants included in the table are exercisable subject to future contingencies (See Note 12)

Collaboration Revenue - Additional Information (Details) - USD ($) $ in Thousands				3 Months Ended			6 Months Ended
	Jun. 22, 2023	Mar. 10, 2023	Jul. 01, 2021	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of ordinary shares	4,250,000	56,666,900
Total consideration				$ 18,761	$ 23,073
Net revenue				7,314		$ 4,368	$ 8,551	$ 9,892
Strategic Collaboration Agreement with Pharming
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Cash upfront payment received			$ 10,000
Strategic Collaboration Agreement with Pharming \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments receivable			$ 189,500
Share Purchase Agreement with Pharming
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of ordinary shares			1,227,738
Total consideration			$ 7,500
Common stock consideration			4,100
Premium consideration			3,400
Pharming Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total upfront payments			17,500
Upfront payments attributed to equity sold			4,100
Upfront payments attributed to research activities			13,400
Estimated reimbursement payments			$ 13,400
Collaborative Arrangement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Net revenue				700		$ 600	1,400	$ 1,100
Contract liabilities, current				800			800
Contract liabilities, long-term				$ 10,800			$ 10,800

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2023	Jul. 31, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Registrant Name	ORCHARD THERAPEUTICS PLC
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001748907
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Common Stock, Shares Outstanding		227,230,079
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	X0
Entity Address, Address Line One	245 Hammersmith Road
Entity Address, City or Town	London
Entity Address, Postal Zip Code	W6 8PW
City Area Code	44
Local Phone Number	(0) 203 808-8286
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-38722
Entity Emerging Growth Company	false
Entity Tax Identification Number	00-0000000
Entity Address, Country	GB
Title of 12(b) Security	American Depositary Shares, each representing tenordinary shares, nominal value £0.10 per share
Trading Symbol	ORTX
Security Exchange Name	NASDAQ

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - GBP (£)	Jun. 30, 2023	Jun. 22, 2023	Mar. 10, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Ordinary Shares, Par Value	£ 0.10	£ 0.1	£ 0.1	£ 0.10
Ordinary Shares, Authorized	£ 33,556,809			£ 13,023,851.5
Ordinary Shares, Issued	227,215,699			126,947,225
Ordinary Shares, Outstanding	227,215,699			126,947,225

Accrued Expenses and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Accrued Liabilities and Other Liabilities [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	June 30,		December 31,
	2023		2022
Accrued external research and development expenses	$	10,985	$	11,230
Accrued payroll and related expenses		9,132		12,312
Accrued professional fees		2,588		2,263
Accrued other		3,459		2,647
Accrued governmental rebates		4,005		2,300
Strimvelis liability - current portion		3,617		3,685
Total accrued expenses and other current liabilities	$	33,786	$	34,437

Commitments and Contingencies - Schedule of Annual Commitments Associated with the Contract (Parenthetical) (Details)	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Exchange rate, Euro to U.S. Dollar	1.08

Fair Value Measurements and Marketable Securities - Schedule of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Maturities in one year or less	$ 117,460	$ 98,277
Maturities between one and three years	3,992	2,971
Total	$ 121,452	$ 101,248

Research and Development Tax Credit Receivable - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Tax Credit Carryforward [Line Items]
Tax incentive receivable, current	$ 8,525	$ 5,942
United Kingdom
Tax Credit Carryforward [Line Items]
Tax incentive receivable, current	10,600
United Kingdom \| Research and Development Expense
Tax Credit Carryforward [Line Items]
Tax incentive receivable, current	2,100	$ 8,500
Additional income tax credits	$ 2,300

Shareholders' Equity

6 Months Ended

Jun. 30, 2023

Equity [Abstract]

Shareholders' Equity

10. Shareholders’ equity

The Company’s ordinary shares are divided into two classes: (i) Ordinary Shares and (ii) Non-Voting Ordinary Shares. The Non-Voting Ordinary Shares have the same rights and restrictions, shall be subject to the same obligations and liabilities, and shall otherwise rank pari passu in all respects with the Ordinary Shares except as set out below:

•

a holder of Non-Voting Ordinary Shares shall, in relation to the Non-Voting Ordinary Shares held by such holder, have no right to receive notice of, or to attend or vote at, any general meeting of shareholders (save in relation to a variation of class rights of the Ordinary Shares); and

•

the Non-Voting Ordinary Shares shall be non-transferable.

A holder of the Non-Voting Ordinary Shares may elect to have some or all of such holder’s Non-Voting Ordinary Shares redesignated as Ordinary Shares by providing a written notice in a form reasonably acceptable to the Company, specifying the number of Non-Voting Ordinary Shares it wishes to have redesignated as Ordinary Shares. Upon the redesignation of the Non-Voting Ordinary Shares to Ordinary Shares, such Ordinary Shares shall rank pari passu with the other Ordinary Shares of the Company in all respects. The holders of Non-Voting Shares are subject to certain ownership restrictions as described in the Securities Purchase Agreement, dated March 6, 2023 (the "Purchase Agreement"), including that no purchaser of Non-Voting Ordinary Shares may redesignate such shares if the holder would own in excess of 19.99% of the number of Ordinary Shares (including Ordinary Shares that may be represented by ADSs) outstanding immediately after giving effect to such redesignation.

At the Company's Annual General Meeting of Shareholders in June 2023, the Company received authority to allot (1) up to a maximum nominal value of £15,158,359 to any new shares (including both Ordinary Shares and Non-Voting Ordinary Shares) pursuant to the Purchase Agreement (the "PIPE Authority") and (2) up to a maximum nominal value of £18,398,450 to any new shares (including both Ordinary Shares and Non-Voting Ordinary Shares) (the "General Authority"). The General Authority was in addition to the previous authority granted to the Board of Directors on June 16, 2021 to grant shares up to a maximum aggregate nominal amount of £13,023,851.50, of which approximately £5,526,095.70 remains (the "2021 Authority"). As of June 30, 2023, the Company had 41,613,400 Ordinary Non-Voting shares issued and outstanding and had 185,602,299 Ordinary Shares issued and outstanding. As of June 30, 2023, the Company has a remaining nominal value of £10,908,359 it can issue in new shares under the PIPE Authority and £23,924,545.70 it can issue in any new shares under the General Authority.

Holders of Ordinary Shares may convert such shares to ADSs. The ADSs are listed on The Nasdaq Capital Market, and each ADS represents ten Ordinary Shares.

We also have in issue one deferred share with a nominal value of £4.89687.

To date, the Company has not declared any dividends. Under English law, a company’s accumulated realized profits must exceed its accumulated realized losses (on a non-consolidated basis) before dividends can be declared and paid. Therefore, the Company must have distributable profits before declaring and paying a dividend.

- Definition

The entire disclosure for equity.

+ References

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+ Details