Adaptimmune Therapeutics (ADAP) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 04, 2021
Cover [Abstract]
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Document Quarterly Report	true
Entity File Number	001-37368
Entity Registrant Name	ADAPTIMMUNE THERAPEUTICS PLC
Entity Incorporation, State or Country Code	X0
Entity Address, Address Line One	60 Jubilee Avenue, Milton Park
Entity Address, City or Town	Abingdon, Oxfordshire
Entity Address, Country	GB
Entity Address, Postal Zip Code	OX14 4RX
City Area Code	44
Entity Tax Identification Number	00-0000000
Title of 12(b) Security	American Depositary Shares, each representing 6 Ordinary Shares, par value £0.001 per share
Local Phone Number	1235 430000
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Trading Symbol	ADAP
Entity Common Stock, Shares Outstanding		932,984,520
Entity Central Index Key	0001621227
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 32,432	$ 56,882
Marketable securities - available-for-sale debt securities	285,512	311,335
Other current assets and prepaid expenses	41,349	29,935
Total current assets	359,293	398,152
Restricted cash	4,604	4,602
Operating lease right-of-use assets, net of accumulated amortization	18,326	18,880
Property, plant and equipment, net of accumulated depreciation of $32,703 (2020: $31,097)	27,739	27,778
Intangibles, net of accumulated amortization	1,619	1,730
Total assets	411,581	451,142
Current liabilities
Accounts payable	4,116	6,389
Operating lease liabilities, current	2,845	2,773
Accrued expenses and other accrued liabilities	22,263	27,079
Deferred revenue, current	2,083	2,832
Total current liabilities	31,307	39,073
Operating lease liabilities, non-current	19,897	20,938
Deferred revenue, non-current	50,565	49,260
Other liabilities, non-current	655	644
Total liabilities	102,424	109,915
Stockholders' equity
Common stock - Ordinary shares par value ?0.001, 1,038,249,630 authorized and 932,817,168 issued and outstanding (2020: 1,038,249,630 authorized and 928,754,958 issued and outstanding)	1,331	1,325
Additional paid in capital	941,569	935,706
Accumulated other comprehensive loss	(10,224)	(10,048)
Accumulated deficit	(623,519)	(585,756)
Total stockholders' equity	309,157	341,227
Total liabilities and stockholders' equity	$ 411,581	$ 451,142

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Thousands	Mar. 31, 2021USD ($)shares	Mar. 31, 2021£ / shares	Dec. 31, 2020USD ($)shares
UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS
Property, plant and equipment, accumulated depreciation | $	$ 32,703		$ 31,097
Common stock, par value | £ / shares		£ 0.001
Common stock, shares authorized	1,038,249,630		1,038,249,630
Common stock, shares issued	932,817,168		928,754,958
Common stock, shares outstanding	932,817,168		928,754,958

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	$ 434	$ 761
Operating expenses
Research and development	(24,506)	(21,264)
General and administrative	(13,817)	(9,261)
Total operating expenses	(38,323)	(30,525)
Operating loss	(37,889)	(29,764)
Interest income	425	730
Other (expense) income, net	(1)	937
Loss before income taxes	(37,465)	(28,097)
Income taxes	(298)	(70)
Net loss attributable to ordinary shareholders	$ (37,763)	$ (28,167)
Net loss per ordinary share - Basic and diluted
Basic and diluted (in dollars per share)	$ (0.04)	$ (0.04)
Weighted average shares outstanding:
Basic and diluted (in shares)	931,088,810	739,753,371

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (37,763)	$ (28,167)
Other comprehensive (loss) income, net of tax
Foreign currency translation adjustments, net of tax of $0, $0 and $0	(3,001)	17,911
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, net of tax of $0 and $0	3,048	(19,651)
Unrealized holding gains (losses) on available-for-sale debt securities, net of tax of $0 and $0	(223)	(586)
Total comprehensive loss for the period	$ (37,939)	$ (30,493)

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Foreign currency translation adjustments, tax	$ 0	$ 0
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, tax	0	0
Unrealized holding gains (losses) on available-for-sale debt securities, tax	$ 0	$ 0

UNAUDITED CONDENSED CONSOLIDA_6

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGE IN EQUITY - USD ($) $ in Thousands	Common stock	Additional paid in capital	Accumulated other comprehensive loss	Accumulated deficit	Total
Balance at the beginning of the period, shares at Dec. 31, 2019	631,003,568
Balance at the beginning of the period at Dec. 31, 2019	$ 943	$ 585,623	$ (7,264)	$ (455,664)	$ 123,638
Increase (Decrease) in Stockholders' Equity
Issuance of shares upon exercise of stock options	$ 6	888			894
Issuance of shares upon exercise of stock options (in shares)	4,610,772
Issuance of shares upon completion of public offering, net of issuance costs	$ 190	90,360			90,550
Issuance of shares upon completion of public offering, net of issuance costs (in shares)	144,900,000
Other comprehensive loss			(2,326)		(2,326)
Share-based compensation expense		1,448			1,448
Net loss				(28,167)	(28,167)
Balance at the end of the period at Mar. 31, 2020	$ 1,139	678,319	(9,590)	(483,831)	$ 186,037
Balance at the end of the period, shares at Mar. 31, 2020	780,514,340
Balance at the beginning of the period, shares at Dec. 31, 2020	928,754,958				928,754,958
Balance at the beginning of the period at Dec. 31, 2020	$ 1,325	935,706	(10,048)	(585,756)	$ 341,227
Increase (Decrease) in Stockholders' Equity
Issuance of shares upon exercise of stock options	$ 6	529			535
Issuance of shares upon exercise of stock options (in shares)	4,062,210
Other comprehensive loss			(176)		(176)
Share-based compensation expense		5,334			5,334
Net loss				(37,763)	(37,763)
Balance at the end of the period at Mar. 31, 2021	$ 1,331	$ 941,569	$ (10,224)	$ (623,519)	$ 309,157
Balance at the end of the period, shares at Mar. 31, 2021	932,817,168				932,817,168

UNAUDITED CONDENSED CONSOLIDA_7

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (37,763)	$ (28,167)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,436	1,711
Share-based compensation expense	5,334	1,448
Unrealized foreign exchange (gains) losses	1,249	(1,745)
Amortization (accretion) on available-for-sale debt securities	1,499	150
Other	1,299	175
Changes in operating assets and liabilities:
Increase in receivables and other operating assets	(11,155)	(3,193)
Increase in non-current operating assets		(259)
Decrease in payables and other current liabilities	(8,601)	(2,708)
Increase in deferred revenue	162	49,445
Net cash (used in) provided by operating activities	(46,540)	16,857
Cash flows from investing activities
Acquisition of property, plant and equipment	(1,152)	(192)
Acquisition of intangibles	(133)	(152)
Maturity or redemption of marketable securities	84,646	26,364
Investment in marketable securities	(61,599)	(97,967)
Net cash provided by (used in) investing activities	21,762	(71,947)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs		90,550
Proceeds from exercise of stock options	534	894
Net cash provided by financing activities	534	91,444
Effect of currency exchange rate changes on cash, cash equivalents and restricted cash	(204)	(502)
Net increase (decrease) in cash, cash equivalents and restricted cash	(24,448)	35,852
Cash, cash equivalents and restricted cash at start of period	61,484	54,908
Cash, cash equivalents and restricted cash at end of period	$ 37,036	$ 90,760

General

General	3 Months Ended
	Mar. 31, 2021
General
General	Note 1 — General Adaptimmune Therapeutics plc is registered in England and Wales. Its registered office is 60 Jubilee Avenue, Milton Park, Abingdon, Oxfordshire, OX14 4RX, United Kingdom. Adaptimmune Therapeutics plc and its subsidiaries (collectively “Adaptimmune” or the “Company”) is a clinical-stage biopharmaceutical company primarily focused on providing novel cell therapies to people with cancer. We are a leader in the development of T-cell therapies for solid tumors. The Company’s The Company is subject to a number of risks similar to other biopharmaceutical companies in the early stage of clinical development including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical programs or clinical programs, the need to obtain marketing approval for its cell therapies, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of its cell therapies, the need to develop a reliable commercial manufacturing process, the need to commercialize any cell therapies that may be approved for marketing, and protection of proprietary technology. If the Company does not successfully commercialize any of its cell therapies, it will be unable to generate product revenue or achieve profitability. The Company had an accumulated deficit of

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	Note 2 — Summary of Significant Accounting Policies (a) Basis of presentation The condensed consolidated financial statements of Adaptimmune Therapeutics plc and its subsidiaries and other financial information included in this Quarterly Report are unaudited and have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and are presented in U.S. dollars. All significant intercompany accounts and transactions between the Company and its subsidiaries have been eliminated on consolidation. The unaudited condensed consolidated financial statements presented in this Quarterly Report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K filed with the SEC on February 25, 2021 (the “Annual Report”). The balance sheet as of December 31, 2020 was derived from audited consolidated financial statements included in the Company’s Annual Report but does not include all disclosures required by U.S. GAAP. The Company’s significant accounting policies are described in Note 2 to those consolidated financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. 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 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. (b) Use of estimates in interim financial statements The preparation of interim financial statements, in conformity with U.S. GAAP and SEC regulations, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the interim financial statements and reported amounts of revenues and expenses during the reporting period. Estimates and assumptions are primarily made in relation to valuation allowances relating to deferred tax assets, revenue recognition, and estimation of the incremental borrowing rate for operating leases. If actual results differ from the Company’s estimates, or to the extent these estimates are adjusted in future periods, the Company’s results of operations could either benefit from, or be adversely affected by, any such change in estimate. (c) Fair value measurements The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The fair value hierarchy prioritizes valuation inputs based on the observable nature of those inputs. The hierarchy defines three levels of valuation inputs: Level 1 - Quoted prices in active markets for identical assets or liabilities Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly Level 3 - Unobservable inputs that reflect the Company's own assumptions about the assumptions market participants would use in pricing the asset or liability The carrying amounts of the Company’s cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses approximate fair value because of the short-term nature of these instruments. The fair value of marketable securities, which are measured at fair value on a recurring basis is detailed in Note 6, Fair value measurements. (d ) New accounting pronouncements Adopted in the period Convertible instruments and contracts in an entity’s own stock On January 1, 2021, the Company adopted ASU 2020-06 - Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40)—Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, To be adopted in future periods Measurement of credit losses on financial instruments In June 2016, the FASB issued ASU 2016-13 - Financial Instruments - Credit losses, which replaces the incurred loss impairment methodology for financial instruments in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The guidance is effective for the fiscal year beginning January 1, 2020, including interim periods within that fiscal year. In November 2019, the FASB issued ASU 2019-10 which resulted in the postponement of the effective date of the new guidance for eligible smaller reporting companies (as defined by the SEC), including the Company, at that time to the fiscal year beginning January 1, 2023; however, earlier adoption is permitted, and the Company may choose to implement the guidance in an earlier fiscal year. The guidance must be adopted using a modified-retrospective approach and a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. The Company is currently evaluating the impact of the guidance on its condensed consolidated financial statements. ​

Revenue

Revenue	3 Months Ended
	Mar. 31, 2021
Revenue
Revenue	Note 3 — Revenue The Company has two contracts with customers: a collaboration and license agreement with GSK and a collaboration agreement with Astellas. Revenue comprises the following categories (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ March 31, ​ ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ Development revenue ​ $ 434 $ 761 ​ ​ $ 434 $ 761 ​ The amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreement as of March 31, 2021 was $64,137,000. Of this, $15,300,000 is allocated to the rights granted for each of the two independent Astellas targets, $7,400,000 is allocated to research services and rights second third ​ Future development, regulatory and sales milestones under both agreements are not considered probable as of March 31, 2021 and have not been included in the transaction price. Reimbursement of the research funding over the co-development period under the Astellas agreement is variable consideration and included in the transaction price as of March 31, 2021 to the extent that a significant reversal of revenue is not probable. ​ The Company expects to recognize revenue for the two independent Astellas targets at a point-in-time upon commencement of the licenses in the event of nomination of the targets, while revenue for the remaining performance obligations will be recognized as development progresses.

Loss per share

Loss per share	3 Months Ended
	Mar. 31, 2021
Loss per share
Loss per share	Note 4 — Loss per share The dilutive effect of 113,556,283 and 93,106,607 stock options outstanding as of March 31, 2021 and 2020 respectively have been excluded from the diluted loss per share calculation for the three months ended March 31, 2021 and 2020, because they would have an antidilutive effect on the loss per share for the period.

Fair value measurements

Fair value measurements	3 Months Ended
	Mar. 31, 2021
Fair value measurements
Fair value measurements	Note 6 — Fair value measurements Assets and liabilities measured at fair value on a recurring basis based on Level 1, Level 2, and Level 3 fair value measurement criteria as of March 31, 2021 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value measurements using ​ ​ March 31, ​ Level 1 ​ Level 2 ​ Level 3 ​ 2021 ​ ​ ​ ​ ​ ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 279,507 $ 279,507 ​ — ​ — Agency bonds ​ ​ 6,005 ​ ​ — ​ ​ 6,005 ​ ​ — ​ $ 285,512 $ 279,507 $ 6,005 $ — ​ The Company estimates the fair value of available-for-sale debt securities with the aid of a third party valuation service, which uses actual trade and indicative prices sourced from third-party providers on a daily basis to estimate the fair value. If observed market prices are not available (for example securities with short maturities and infrequent secondary market trades), the securities are priced using a valuation model maximizing observable inputs, including market interest rates.

Marketable securities - availab

Marketable securities - available-for-sale debt securities	3 Months Ended
	Mar. 31, 2021
Marketable securities - available-for-sale debt securities
Marketable securities - available-for-sale debt securities	Note 7 — Marketable securities – available-for-sale debt securities As of March 31, 2021, the Company has the following investments in marketable securities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ Aggregate ​ ​ Remaining ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Contractual Maturity Cost Gains Losses Fair Value Available-for-sale debt securities: ​ ​ ​ ​ Corporate debt securities Less than 3 months ​ $ 54,372 ​ $ 15 ​ $ (11) ​ $ 54,376 Corporate debt securities ​ 3 months to 1 year ​ ​ 114,136 ​ ​ 35 ​ ​ (39) ​ ​ 114,132 Agency bonds ​ 1 year to 2 years ​ ​ 5,999 ​ ​ 6 ​ ​ — ​ ​ 6,005 Corporate debt securities ​ 1 year to 2 years ​ ​ 111,119 ​ ​ 53 ​ ​ (173) ​ ​ 110,999 ​ ​ $ 285,626 ​ $ 109 ​ $ (223) ​ $ 285,512 ​ The aggregate fair value (in thousands) and number of securities held by the Company (including those classified as cash equivalents) in an unrealized loss position as of March 31, 2021 and 31 December, 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ December 31, 2020 ​ Fair market value of investments in an unrealized loss position ​ Number of investments in an unrealized loss position Unrealized losses ​ Fair market value of investments in an unrealized loss position ​ Number of investments in an unrealized loss position ​ Unrealized losses Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 199,148 ​ 37 $ (223) $ 157,985 ​ 30 $ (158) ​ As of March 31, 2021, the securities in an unrealized loss position are not considered to be other than temporarily impaired because the impairments are not severe and have been for a short duration. No securities have been in an unrealized loss position for more than one year. The Company does not intend to sell the debt securities in an unrealized loss position and believes that it has the ability to hold the debt securities to maturity. ​

Other current assets

Other current assets	3 Months Ended
	Mar. 31, 2021
Other current assets
Other current assets	Note 8 — Other current assets Other current assets consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 Corporate tax receivable $ 31,141 $ 20,585 Prepayments ​ 5,689 ​ 6,314 Clinical materials ​ 1,576 ​ 2,086 Other current assets ​ 2,943 ​ 950 ​ ​ $ 41,349 ​ $ 29,935 ​

Accrued expenses and other curr

Accrued expenses and other current liabilities	3 Months Ended
	Mar. 31, 2021
Accrued expenses and other current liabilities
Accrued expenses and other current liabilities	Note 9 — Accrued expenses and other current liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 Accrued clinical and development expenditure ​ $ 13,577 ​ $ 13,081 Accrued employee expenses ​ ​ 5,836 ​ ​ 11,825 Other accrued expenditure ​ ​ 2,459 ​ ​ 2,126 Other ​ 391 ​ 47 ​ ​ $ 22,263 ​ $ 27,079 ​

Contingencies and commitments

Contingencies and commitments	3 Months Ended
	Mar. 31, 2021
Contingencies and commitments
Contingencies and commitments	​ Note 10 — Contingencies and commitments On January 7, 2021, the Company entered into an agreement with a third party, whereby the third party is responsible for the development, manufacture, submission of regulatory filings and commercialization of a companion diagnostic for the detection of the MAGE-A4 biomarker. The Company shall compensate the third party for its performance of activities under the agreement based on milestone payments and reimbursement of direct expenses. The agreement is non-exclusive and the third party can sell the companion diagnostic to other parties. Once the companion diagnostic is approved and launched, the Company guarantees a minimum revenue to the third party. The agreement can be terminated by the Company and the third party upon 60 days’ notice, if certain conditions are met. ​

Share-based compensation

Share-based compensation	3 Months Ended
	Mar. 31, 2021
Share-based compensation
Share-based compensation	Note 11 — Share-based compensation The following table shows the total share-based compensation expense included in the unaudited consolidated statements of operations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2021 2020 ​ ​ Research and development ​ $ 2,375 ​ $ 978 ​ ​ General and administrative ​ 2,959 ​ ​ 470 ​ ​ ​ ​ $ 5,334 ​ $ 1,448 ​ ​ ​ The following table shows information about share options and options which have a nominal exercise price (similar to restricted stock units (RSUs)) granted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ March 31, ​ 2021 2020 ​ Number of options over ordinary shares granted ​ ​ 14,803,056 ​ ​ 10,229,280 ​ Weighted average fair value of ordinary shares options ​ $ 0.75 ​ $ 0.51 ​ Number of additional options with a nominal exercise price granted ​ ​ 12,663,792 ​ ​ 6,060,696 ​ Weighted average fair value of options with a nominal exercise price ​ $ 1.03 ​ $ 0.74 ​ ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies
Basis of presentation	(a) Basis of presentation The condensed consolidated financial statements of Adaptimmune Therapeutics plc and its subsidiaries and other financial information included in this Quarterly Report are unaudited and have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) and are presented in U.S. dollars. All significant intercompany accounts and transactions between the Company and its subsidiaries have been eliminated on consolidation. The unaudited condensed consolidated financial statements presented in this Quarterly Report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K filed with the SEC on February 25, 2021 (the “Annual Report”). The balance sheet as of December 31, 2020 was derived from audited consolidated financial statements included in the Company’s Annual Report but does not include all disclosures required by U.S. GAAP. The Company’s significant accounting policies are described in Note 2 to those consolidated financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. 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 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.
Use of estimates in financial statements	(b) Use of estimates in interim financial statements The preparation of interim financial statements, in conformity with U.S. GAAP and SEC regulations, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the interim financial statements and reported amounts of revenues and expenses during the reporting period. Estimates and assumptions are primarily made in relation to valuation allowances relating to deferred tax assets, revenue recognition, and estimation of the incremental borrowing rate for operating leases. If actual results differ from the Company’s estimates, or to the extent these estimates are adjusted in future periods, the Company’s results of operations could either benefit from, or be adversely affected by, any such change in estimate.
Fair value measurements	(c) Fair value measurements The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The fair value hierarchy prioritizes valuation inputs based on the observable nature of those inputs. The hierarchy defines three levels of valuation inputs: Level 1 - Quoted prices in active markets for identical assets or liabilities Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly Level 3 - Unobservable inputs that reflect the Company's own assumptions about the assumptions market participants would use in pricing the asset or liability The carrying amounts of the Company’s cash and cash equivalents, restricted cash, accounts receivable, accounts payable and accrued expenses approximate fair value because of the short-term nature of these instruments. The fair value of marketable securities, which are measured at fair value on a recurring basis is detailed in Note 6, Fair value measurements.
New accounting pronouncements	(d ) New accounting pronouncements Adopted in the period Convertible instruments and contracts in an entity’s own stock On January 1, 2021, the Company adopted ASU 2020-06 - Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40)—Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, To be adopted in future periods Measurement of credit losses on financial instruments In June 2016, the FASB issued ASU 2016-13 - Financial Instruments - Credit losses, which replaces the incurred loss impairment methodology for financial instruments in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The guidance is effective for the fiscal year beginning January 1, 2020, including interim periods within that fiscal year. In November 2019, the FASB issued ASU 2019-10 which resulted in the postponement of the effective date of the new guidance for eligible smaller reporting companies (as defined by the SEC), including the Company, at that time to the fiscal year beginning January 1, 2023; however, earlier adoption is permitted, and the Company may choose to implement the guidance in an earlier fiscal year. The guidance must be adopted using a modified-retrospective approach and a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. The Company is currently evaluating the impact of the guidance on its condensed consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue
Summary of revenue categories	Revenue comprises the following categories (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ March 31, ​ ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ Development revenue ​ $ 434 $ 761 ​ ​ $ 434 $ 761

Accumulated other comprehensive

Accumulated other comprehensive income (loss) (Tables)	3 Months Ended
	Mar. 31, 2021
Accumulated other comprehensive income (loss)
Schedule of changes in Accumulated other comprehensive (loss) income	The following table shows the changes in Accumulated other comprehensive (loss) income (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ Accumulated ​ ​ Total ​ ​ foreign ​ unrealized ​ ​ accumulated ​ ​ currency ​ gains (losses) on ​ ​ other ​ translation available-for-sale ​ ​ comprehensive ​ ​ adjustments ​ debt securities ​ ​ (loss) income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at January 1, 2021 $ (10,158) ​ $ 110 ​ $ (10,048) Foreign currency translation adjustments ​ ​ (3,001) ​ ​ — ​ ​ (3,001) Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0 ​ ​ 3,048 ​ ​ — ​ ​ 3,048 Unrealized holding losses on available-for-sale debt securities, net of tax of $0 ​ ​ — ​ ​ (223) ​ ​ (223) Balance at March 31, 2021 ​ $ (10,111) ​ $ (113) ​ $ (10,224) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ Accumulated ​ Total ​ ​ foreign ​ unrealized ​ accumulated ​ ​ currency ​ gains (losses) on ​ other ​ translation available-for-sale ​ comprehensive ​ ​ adjustments ​ debt securities ​ (loss) income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at January 1, 2020 $ (7,302) ​ $ 38 ​ $ (7,264) Foreign currency translation adjustments ​ ​ 17,911 ​ ​ — ​ ​ 17,911 Foreign currency losses on intercompany loan of a long-term investment nature, net of tax of $0 ​ ​ (19,651) ​ ​ — ​ ​ (19,651) Unrealized holding losses on available-for-sale debt securities, net of tax of $0 ​ ​ — ​ ​ (586) ​ ​ (586) Balance at March 31, 2020 ​ $ (9,042) ​ $ (548) ​ $ (9,590)

Fair value measurements (Tables

Fair value measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair value measurements
Summary of fair value of assets and liabilities on a recurring basis based on fair value measurement criteria	Assets and liabilities measured at fair value on a recurring basis based on Level 1, Level 2, and Level 3 fair value measurement criteria as of March 31, 2021 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value measurements using ​ ​ March 31, ​ Level 1 ​ Level 2 ​ Level 3 ​ 2021 ​ ​ ​ ​ ​ ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 279,507 $ 279,507 ​ — ​ — Agency bonds ​ ​ 6,005 ​ ​ — ​ ​ 6,005 ​ ​ — ​ $ 285,512 $ 279,507 $ 6,005 $ —

Marketable securities - avail_2

Marketable securities - available-for-sale debt securities (Tables)	3 Months Ended
	Mar. 31, 2021
Marketable securities - available-for-sale debt securities
Schedule of investments in marketable securities	As of March 31, 2021, the Company has the following investments in marketable securities (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ Aggregate ​ ​ Remaining ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Contractual Maturity Cost Gains Losses Fair Value Available-for-sale debt securities: ​ ​ ​ ​ Corporate debt securities Less than 3 months ​ $ 54,372 ​ $ 15 ​ $ (11) ​ $ 54,376 Corporate debt securities ​ 3 months to 1 year ​ ​ 114,136 ​ ​ 35 ​ ​ (39) ​ ​ 114,132 Agency bonds ​ 1 year to 2 years ​ ​ 5,999 ​ ​ 6 ​ ​ — ​ ​ 6,005 Corporate debt securities ​ 1 year to 2 years ​ ​ 111,119 ​ ​ 53 ​ ​ (173) ​ ​ 110,999 ​ ​ $ 285,626 ​ $ 109 ​ $ (223) ​ $ 285,512
Schedule of aggregate fair value	The aggregate fair value (in thousands) and number of securities held by the Company (including those classified as cash equivalents) in an unrealized loss position as of March 31, 2021 and 31 December, 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ December 31, 2020 ​ Fair market value of investments in an unrealized loss position ​ Number of investments in an unrealized loss position Unrealized losses ​ Fair market value of investments in an unrealized loss position ​ Number of investments in an unrealized loss position ​ Unrealized losses Marketable securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 199,148 ​ 37 $ (223) $ 157,985 ​ 30 $ (158)

Other current assets (Tables)

Other current assets (Tables)	3 Months Ended
	Mar. 31, 2021
Other current assets
Summary of other current assets	Other current assets consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 Corporate tax receivable $ 31,141 $ 20,585 Prepayments ​ 5,689 ​ 6,314 Clinical materials ​ 1,576 ​ 2,086 Other current assets ​ 2,943 ​ 950 ​ ​ $ 41,349 ​ $ 29,935

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Accrued expenses and other current liabilities
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2021 2020 Accrued clinical and development expenditure ​ $ 13,577 ​ $ 13,081 Accrued employee expenses ​ ​ 5,836 ​ ​ 11,825 Other accrued expenditure ​ ​ 2,459 ​ ​ 2,126 Other ​ 391 ​ 47 ​ ​ $ 22,263 ​ $ 27,079

Share-based compensation (Table

Share-based compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based compensation
Summary of share-based compensation expense included in the consolidated statements of operations	The following table shows the total share-based compensation expense included in the unaudited consolidated statements of operations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2021 2020 ​ ​ Research and development ​ $ 2,375 ​ $ 978 ​ ​ General and administrative ​ 2,959 ​ ​ 470 ​ ​ ​ ​ $ 5,334 ​ $ 1,448 ​ ​
Summary of all stock option activity	​ The following table shows information about share options and options which have a nominal exercise price (similar to restricted stock units (RSUs)) granted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ March 31, ​ 2021 2020 ​ Number of options over ordinary shares granted ​ ​ 14,803,056 ​ ​ 10,229,280 ​ Weighted average fair value of ordinary shares options ​ $ 0.75 ​ $ 0.51 ​ Number of additional options with a nominal exercise price granted ​ ​ 12,663,792 ​ ​ 6,060,696 ​ Weighted average fair value of options with a nominal exercise price ​ $ 1.03 ​ $ 0.74 ​

General (Details)

General (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
General
Accumulated deficit	$ 623,519	$ 585,756

Revenue - Revenue from contract

Revenue - Revenue from contracts with customers (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)customer	Mar. 31, 2020USD ($)
Revenue
Revenue	$ 434	$ 761
Number of contracts with customers | customer	2
Increase in deferred revenue	$ 162	49,445
Development revenue
Revenue
Revenue	$ 434	$ 761

Revenue - Collaboration Agreeme

Revenue - Collaboration Agreement - Performance obligations (Details)	3 Months Ended
	Mar. 31, 2021USD ($)item
Astellas Collaboration Agreement
Performance obligations
Number of co-development targets	3
Number of independent targets | item	2
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	$ 64,137,000
Astellas Collaboration Agreement | Rights granted, first independent target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	15,300,000
Astellas Collaboration Agreement | Rights granted, second independent target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	15,300,000
Astellas Collaboration Agreement | Research services and rights granted under the co-exclusive license, first co-development target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	18,500,000
Astellas Collaboration Agreement | Research services and rights under the co-exclusive license, second co-development target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	7,400,000
Astellas Collaboration Agreement | Research services and rights under the co-exclusive license, third co-development target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	7,400,000
GSK Collaboration And License Agreement | Research services for the third target under the agreement with GSK
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue	$ 237,000

Loss per share - Antidilutive s

Loss per share - Antidilutive shares (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share options
Antidilutive securities
Potentially dilutive equity instruments excluded from the diluted loss per share (in shares)	113,556,283	93,106,607

Accumulated other comprehensi_2

Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated other comprehensive loss
Total accumulated other comprehensive (loss) income	$ (10,048)
Foreign currency translation adjustments, net of tax of $0, $0 and $0	(3,001)	$ 17,911
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, net of tax of $0 and $0	3,048	(19,651)
Unrealized holding gains (losses) on available-for-sale debt securities, net of tax of $0 and $0	(223)	(586)
Total accumulated other comprehensive (loss) income	(10,224)
Accumulated other comprehensive loss (paranthetical)
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, tax	0	0
Unrealized holding gains (losses) on available-for-sale debt securities, tax	0	0
Accumulated foreign currency translation adjustments
Accumulated other comprehensive loss
Total accumulated other comprehensive (loss) income	(10,158)	(7,302)
Foreign currency translation adjustments, net of tax of $0, $0 and $0	(3,001)	17,911
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, net of tax of $0 and $0	3,048	(19,651)
Total accumulated other comprehensive (loss) income	(10,111)	(9,042)
Accumulated unrealized gains (losses) on available-for-sale debt securities
Accumulated other comprehensive loss
Total accumulated other comprehensive (loss) income	110	38
Unrealized holding gains (losses) on available-for-sale debt securities, net of tax of $0 and $0	(223)	(586)
Total accumulated other comprehensive (loss) income	(113)	(548)
Accumulated other comprehensive loss
Accumulated other comprehensive loss
Total accumulated other comprehensive (loss) income	(10,048)	(7,264)
Foreign currency translation adjustments, net of tax of $0, $0 and $0	(3,001)	17,911
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, net of tax of $0 and $0	3,048	(19,651)
Unrealized holding gains (losses) on available-for-sale debt securities, net of tax of $0 and $0	(223)	(586)
Total accumulated other comprehensive (loss) income	$ (10,224)	$ (9,590)

Fair value measurements (Detail

Fair value measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	$ 285,512	$ 311,335
Recurring basis
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	285,512
Recurring basis | Corporate debt securities
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	279,507
Recurring basis | Agency bonds
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	6,005
Recurring basis | Level 1
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	279,507
Recurring basis | Level 1 | Corporate debt securities
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	279,507
Recurring basis | Level 2
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	6,005
Recurring basis | Level 2 | Agency bonds
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	$ 6,005

Marketable securities - Avail_3

Marketable securities - Available-for-sale debt securities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Debt Securities
Marketable securities
Amortized cost	$ 285,626
Gross unrealized gains	109
Gross unrealized losses	(223)
Aggregate estimated fair value	285,512
Corporate Debt Securities Maturity Period Less Than Three Months | Debt Securities
Marketable securities
Amortized cost	54,372
Gross unrealized gains	15
Gross unrealized losses	(11)
Aggregate estimated fair value	54,376
Corporate Debt Securities Maturity Period Three Months To One Year
Marketable securities
Amortized cost	114,136
Gross unrealized gains	35
Gross unrealized losses	(39)
Aggregate estimated fair value	114,132
Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities
Marketable securities
Amortized cost	111,119
Gross unrealized gains	53
Gross unrealized losses	(173)
Aggregate estimated fair value	110,999
Agency Bond Maturity Period One Year To Two Years | Marketable securities
Marketable securities
Amortized cost	5,999
Gross unrealized gains	6
Aggregate estimated fair value	$ 6,005
Minimum | Corporate Debt Securities Maturity Period One Year or Less | Debt Securities
Marketable securities
Available For Sale Securities Debt Maturity Period	3 months
Minimum | Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities
Marketable securities
Available For Sale Securities Debt Maturity Period	1 year
Minimum | Agency Bond Maturity Period One Year To Two Years | Marketable securities
Marketable securities
Available For Sale Securities Debt Maturity Period	1 year
Maximum | Corporate Debt Securities Maturity Period Less Than Three Months | Debt Securities
Marketable securities
Available For Sale Securities Debt Maturity Period	3 months
Maximum | Corporate Debt Securities Maturity Period One Year or Less | Debt Securities
Marketable securities
Available For Sale Securities Debt Maturity Period	1 year
Maximum | Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities
Marketable securities
Available For Sale Securities Debt Maturity Period	2 years
Maximum | Agency Bond Maturity Period One Year To Two Years | Marketable securities
Marketable securities
Available For Sale Securities Debt Maturity Period	2 years

Marketable securities - Avail_4

Marketable securities - Available-for-sale debt securities - Unrealized loss position (Details) $ in Thousands	Mar. 31, 2021USD ($)security	Dec. 31, 2020USD ($)
Marketable securities
Number of available-for-sale securities in an unrealized loss position for more than one year | security	0
Corporate debt securities | Debt Securities
Marketable securities
Fair market value of investments in an unrealized loss position	$ 199,148	$ 157,985
Number of investments in an unrealized loss position	37	30
Unrealized losses	$ (223)	$ (158)

Other current assets (Details)

Other current assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other current assets
Corporate tax receivable	$ 31,141	$ 20,585
Prepayments	5,689	6,314
Clinical materials	1,576	2,086
Other current assets	2,943	950
Total	$ 41,349	$ 29,935

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accrued expenses and other current liabilities
Accrued clinical and development expenditure	$ 13,577	$ 13,081
Accrued employee expenses	5,836	11,825
Other accrued expenditure	2,459	2,126
Other	391	47
Total	$ 22,263	$ 27,079

Share-based compensation - Shar

Share-based compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	$ 5,334	$ 1,448
Research and development
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	2,375	978
General and administrative
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	$ 2,959	$ 470

Share-based compensation - Opti

Share-based compensation - Options (Details) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based compensation
Number of options granted (in shares)	14,803,056	10,229,280
Weighted average fair value (in dollars per share)	$ 0.75	$ 0.51
Number of additional options with a nominal exercise price granted	12,663,792	6,060,696
Weighted average fair value of RSU-style options granted	$ 1.03	$ 0.74