Adaptimmune Therapeutics (ADAP) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 04, 2020
Cover [Abstract]
Document Type	10-Q
Document Period End Date	Sep. 30, 2020
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	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Trading Symbol	ADAP
Entity Common Stock, Shares Outstanding		928,672,584
Entity Central Index Key	0001621227
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 78,466	$ 50,412
Marketable securities - available-for-sale debt securities	321,442	39,130
Other current assets and prepaid expenses (including current portion of clinical materials)	26,825	30,947
Total current assets	426,733	120,489
Restricted cash	4,441	4,496
Clinical materials	160	2,503
Operating lease right-of-use assets, net of accumulated amortization	18,775	20,789
Property, plant and equipment, net of accumulated depreciation of $26,100 (2019: $23,649)	26,943	31,068
Intangibles, net of accumulated amortization	1,970	2,198
Total assets	479,022	181,543
Current liabilities
Accounts payable	4,030	6,357
Operating lease liabilities, current	2,619	2,493
Accrued expenses and other accrued liabilities	24,615	23,363
Deferred revenue, current	3,635	2,128
Total current liabilities	34,899	34,341
Operating lease liabilities, non-current	21,090	22,966
Deferred revenue, non-current	46,212
Other liabilities, non-current	615	598
Total liabilities	102,816	57,905
Stockholders' equity
Common stock - Ordinary shares par value ?0.001, 1,038,249,630 authorized and 928,525,410	1,325	943
Additional paid in capital	932,518	585,623
Accumulated other comprehensive loss	(8,494)	(7,264)
Accumulated deficit	(549,143)	(455,664)
Total stockholders' equity	376,206	123,638
Total liabilities and stockholders' equity	$ 479,022	$ 181,543

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) $ in Thousands	Sep. 30, 2020USD ($)shares	Sep. 30, 2020£ / shares	Dec. 31, 2019USD ($)shares
CONSOLIDATED BALANCE SHEETS
Property, plant and equipment, accumulated depreciation | $	$ 28,503		$ 23,649
Common stock, par value | £ / shares		£ 0.001
Common stock, shares authorized	1,038,249,630		785,857,300
Common stock, shares issued	928,525,410		631,003,568
Common stock, shares outstanding	928,525,410		631,003,568

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	$ 1,193	$ 237	$ 2,456	$ 394
Operating expenses
Research and development (including losses accrued on firm purchase commitments of $0, $5,000, $0 and $5,000)	(24,067)	(29,617)	(65,791)	(77,147)
General and administrative	(13,001)	(10,741)	(32,557)	(32,662)
Total operating expenses	(37,068)	(40,358)	(98,348)	(109,809)
Operating loss	(35,875)	(40,121)	(95,892)	(109,415)
Interest income	2,147	615	4,024	2,324
Other (expense) income, net	(1,689)	291	(1,501)	(556)
Loss before income taxes	(35,417)	(39,215)	(93,369)	(107,647)
Income tax expense	(15)	(87)	(110)	(154)
Net loss attributable to ordinary shareholders	$ (35,432)	$ (39,302)	$ (93,479)	$ (107,801)
Net loss per ordinary share - Basic and diluted
Basic and diluted (in dollars per share)	$ (0.04)	$ (0.06)	$ (0.11)	$ (0.17)
Weighted average shares outstanding:
Basic and diluted (in shares)	928,022,057	630,866,800	829,973,177	629,403,293

UNAUDITED CONSOLIDATED STATEMEN

UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
Losses accrued on firm purchase commitments	$ 0	$ 5,000	$ 0	$ 5,000

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (35,432)	$ (39,302)	$ (93,479)	$ (107,801)
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments, net of tax of $0, $0, $0 and $0	(15,522)	6,617	3,583	7,916
Foreign currency gains (losses) on intercompany loan of a long-term investment nature, net of tax of $0, $0, $0 and $0	15,698	(8,388)	(5,061)	(8,388)
Unrealized gains (losses) on available-for-sale debt securities
Unrealized holding gains (losses) on available-for-sale debt securities, net of tax of $0, $0, $0 and $0	211	(55)	324	223
Reclassification adjustment for (gains) losses on available-for-sale debt securities included in net loss, net of tax of $0 and $0	(76)		(76)	(13)
Total comprehensive loss for the period	$ (35,121)	$ (41,128)	$ (94,709)	$ (108,063)

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Foreign currency translation adjustments, tax	$ 0			$ 0			$ 0	$ 0
Foreign currency losses on intercompany loan of a long-term investment nature, tax	0	$ 0	$ 0	0			0	0
Reclassification adjustment for gains on available-for-sale debt securities included in net loss, tax	0			0	$ 0		0	0
Unrealized holding gains on available-for-sale debt securities, tax	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0

UNAUDITED CONDENSED CONSOLIDA_6

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Common stock	Additional paid in capital	Accumulated foreign currency translation adjustments	Accumulated unrealized gains (losses) on available-for-sale debt securities	Accumulated deficit	Total
Balance at the beginning of the period, shares at Dec. 31, 2018	627,454,270
Balance at the beginning of the period at Dec. 31, 2018	$ 939	$ 574,208	$ (9,607)	$ (156)	$ (318,499)	$ 246,885
Increase (Decrease) in Stockholders' Equity
Net loss					(27,412)	(27,412)
Issuance of shares upon exercise of stock options	$ 1	35				36
Issuance of shares upon exercise of stock options (in shares)	840,432
Other comprehensive loss before reclassifications
Foreign currency translation adjustments			(3,543)			(3,543)
Unrealized holding gains on available-for-sale debt securities, net of tax				210		210
Share-based compensation expense		3,479				3,479
Balance at the end of the period at Mar. 31, 2019	$ 940	577,722	(13,150)	54	(345,911)	219,655
Balance at the end of the period, shares at Mar. 31, 2019	628,294,702
Balance at the beginning of the period, shares at Dec. 31, 2018	627,454,270
Balance at the beginning of the period at Dec. 31, 2018	$ 939	574,208	(9,607)	(156)	(318,499)	246,885
Increase (Decrease) in Stockholders' Equity
Net loss						(107,801)
Other comprehensive loss before reclassifications
Foreign currency translation adjustments						7,916
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0						(8,388)
Unrealized holding gains on available-for-sale debt securities, net of tax						223
Reclassification from accumulated other comprehensive income of losses on available-for-sale debt securities included in net income, net of tax of $0						(13)
Balance at the end of the period at Sep. 30, 2019	$ 943	583,065	(10,079)	54	(426,300)	147,683
Balance at the end of the period, shares at Sep. 30, 2019	630,952,736
Balance at the beginning of the period, shares at Mar. 31, 2019	628,294,702
Balance at the beginning of the period at Mar. 31, 2019	$ 940	577,722	(13,150)	54	(345,911)	219,655
Increase (Decrease) in Stockholders' Equity
Net loss					(41,087)	(41,087)
Issuance of shares upon exercise of stock options	$ 3	327				330
Issuance of shares upon exercise of stock options (in shares)	2,377,876
Other comprehensive loss before reclassifications
Foreign currency translation adjustments			4,842			4,842
Unrealized holding gains on available-for-sale debt securities, net of tax				68		68
Reclassification from accumulated other comprehensive income of losses on available-for-sale debt securities included in net income, net of tax of $0				(13)		(13)
Share-based compensation expense		3,196				3,196
Balance at the end of the period at Jun. 30, 2019	$ 943	581,245	(8,308)	109	(386,998)	186,991
Balance at the end of the period, shares at Jun. 30, 2019	630,672,578
Increase (Decrease) in Stockholders' Equity
Net loss					(39,302)	(39,302)
Issuance of shares upon exercise of stock options (in shares)	280,158
Other comprehensive loss before reclassifications
Foreign currency translation adjustments			6,617			6,617
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0			(8,388)			(8,388)
Unrealized holding gains on available-for-sale debt securities, net of tax				(55)		(55)
Share-based compensation expense		1,820				1,820
Balance at the end of the period at Sep. 30, 2019	$ 943	583,065	(10,079)	54	(426,300)	$ 147,683
Balance at the end of the period, shares at Sep. 30, 2019	630,952,736
Balance at the beginning of the period, shares at Dec. 31, 2019	631,003,568					631,003,568
Balance at the beginning of the period at Dec. 31, 2019	$ 943	585,623	(7,302)	38	(455,664)	$ 123,638
Increase (Decrease) in Stockholders' Equity
Net loss					(28,167)	(28,167)
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 before reclassifications
Foreign currency translation adjustments			17,911			17,911
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0			(19,651)			(19,651)
Unrealized holding gains on available-for-sale debt securities, net of tax				(586)		(586)
Share-based compensation expense		1,448				1,448
Balance at the end of the period at Mar. 31, 2020	$ 1,139	678,319	(9,042)	(548)	(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, 2019	631,003,568					631,003,568
Balance at the beginning of the period at Dec. 31, 2019	$ 943	585,623	(7,302)	38	(455,664)	$ 123,638
Increase (Decrease) in Stockholders' Equity
Net loss						(93,479)
Other comprehensive loss before reclassifications
Foreign currency translation adjustments						3,583
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0						(5,061)
Unrealized holding gains on available-for-sale debt securities, net of tax						324
Reclassification from accumulated other comprehensive income of losses on available-for-sale debt securities included in net income, net of tax of $0						(76)
Balance at the end of the period at Sep. 30, 2020	$ 1,325	932,518	(8,780)	286	(549,143)	$ 376,206
Balance at the end of the period, shares at Sep. 30, 2020	928,525,410					928,525,410
Balance at the beginning of the period, shares at Mar. 31, 2020	780,514,340
Balance at the beginning of the period at Mar. 31, 2020	$ 1,139	678,319	(9,042)	(548)	(483,831)	$ 186,037
Increase (Decrease) in Stockholders' Equity
Net loss					(29,880)	(29,880)
Issuance of shares upon exercise of stock options	$ 7	4,174				4,181
Issuance of shares upon exercise of stock options (in shares)	5,704,606
Issuance of shares upon completion of public offering, net of issuance costs	$ 178	243,660				243,838
Issuance of shares upon completion of public offering, net of issuance costs (in shares)	141,450,000
Other comprehensive loss before reclassifications
Foreign currency translation adjustments			1,194			1,194
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0			(1,108)			(1,108)
Unrealized holding gains on available-for-sale debt securities, net of tax				699		699
Share-based compensation expense		2,624				2,624
Balance at the end of the period at Jun. 30, 2020	$ 1,324	928,777	(8,956)	151	(513,711)	407,585
Balance at the end of the period, shares at Jun. 30, 2020	927,668,946
Increase (Decrease) in Stockholders' Equity
Net loss					(35,432)	(35,432)
Issuance of shares upon exercise of stock options	$ 1	461				462
Issuance of shares upon exercise of stock options (in shares)	856,464
Other comprehensive loss before reclassifications
Foreign currency translation adjustments			(15,522)			(15,522)
Foreign currency gains on intercompany loan of a long-term investment nature, net of tax of $0			15,698			15,698
Unrealized holding gains on available-for-sale debt securities, net of tax				211		211
Reclassification from accumulated other comprehensive income of losses on available-for-sale debt securities included in net income, net of tax of $0				(76)		(76)
Share-based compensation expense		3,280				3,280
Balance at the end of the period at Sep. 30, 2020	$ 1,325	$ 932,518	$ (8,780)	$ 286	$ (549,143)	$ 376,206
Balance at the end of the period, shares at Sep. 30, 2020	928,525,410					928,525,410

UNAUDITED CONDENSED CONSOLIDA_7

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net loss	$ (93,479)	$ (107,801)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	5,151	5,406
Amortization	718	511
Share-based compensation expense	7,352	8,495
Unrealized foreign exchange (gains) losses	(1,102)	522
Other	2,817	(208)
Changes in operating assets and liabilities:
Decrease (increase) in receivables and other operating assets	3,345	(20,075)
Decrease in non-current operating assets	2,291	1,468
(Decrease) increase in payables and other current liabilities	(117)	8,879
Increase in deferred revenue	48,649	2,824
Net cash used in operating activities	(24,375)	(99,979)
Cash flows from investing activities
Acquisition of property, plant and equipment	(1,174)	(1,425)
Acquisition of intangibles	(496)	(1,036)
Maturity or redemption of marketable securities	78,915	92,803
Investment in marketable securities	(363,777)	(19,080)
Net cash (used in) provided by investing activities	(286,532)	71,262
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	334,388
Proceeds from exercise of stock options	5,541	366
Net cash provided by financing activities	339,929	366
Effect of currency exchange rate changes on cash, cash equivalents and restricted cash	(1,023)	(398)
Net increase (decrease) in cash, cash equivalents and restricted cash	27,999	(28,749)
Cash, cash equivalents and restricted cash at start of period	54,908	72,476
Cash, cash equivalents and restricted cash at end of period	$ 82,907	$ 43,727

General

General	9 Months Ended
	Sep. 30, 2020
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	9 Months Ended
	Sep. 30, 2020
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 27, 2020 (the “Annual Report”). The balance sheet as of December 31, 2019 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 the valuation of share options, valuation allowances relating to deferred tax assets, revenue recognition, estimation of the incremental borrowing rate for operating leases, estimating clinical trial expenses and estimating R&D tax and expenditure credits. 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 Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract On January 1, 2020, the Company adopted ASU 2018-15 – Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The guidance aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The Company elected to apply the guidance prospectively to all implementation costs incurred after the date of adoption. The guidance has not had a material effect on the condensed consolidated financial statements. Simplifying the Accounting for Income Taxes On January 1, 2020, the Company adopted ASU 2019-12 – Simplifying the Accounting for Income Taxes (Topic 740). The simplifications to accounting for income taxes cover a variety of areas, including the removal of the exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items (for example, discontinued operations or other comprehensive income). The changes also add a requirement for an entity to reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. Most of the amendments should be applied on a prospective basis. The guidance has not had a material effect on the condensed consolidated financial statements. Changes to the Disclosure Requirements for Fair Value Measurement On January 1, 2020, the Company adopted ASU 2018-13 – Fair Value Measurement (Topic 820) - Disclosure Framework— Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. Certain amendments apply prospectively with all other amendments applied retrospectively to all periods presented upon their effective date. The guidance has not had a material effect on the condensed consolidated financial statements. Revenue Recognition in Collaborative Arrangements On January 1, 2020, the Company adopted ASU 2018-18 – Collaborative Arrangements — Clarifying the Interaction between Topic 808 and Topic 606, which clarifies that certain transactions between collaborative arrangement participants should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account. In those situations, all the guidance in Topic 606 should be applied, including recognition, measurement, presentation, and disclosure requirements. The guidance has been applied retrospectively to all contracts that were not completed at the date of initial application of Topic 606. The guidance has not had a material effect on the condensed consolidated financial statements because it did not change the Company’s accounting for existing or previous collaborative arrangements. ​ 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 to the fiscal year beginning January 1, 2023. The Company currently intends to adopt the guidance in the fiscal year beginning January 1, 2023. 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	9 Months Ended
	Sep. 30, 2020
Revenue
Revenue	Note 3 — Revenue The Company has two contracts with customers: a collaboration and license agreement with GSK (the “GSK Collaboration and License Agreement”) and a collaboration agreement with Astellas Pharma Inc. (the “Astellas Collaboration Agreement”) through its wholly-owned subsidiary, Universal Cells, Inc. (“Astellas”). Development revenue from contracts with customers in the three and nine months ended September 30, 2020 comprises the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ September 30, ​ September 30, ​ 2020 2019 ​ 2020 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Development revenue $ 1,193 $ 237 ​ $ 2,456 $ 394 ​ $ 1,193 $ 237 ​ $ 2,456 $ 394 ​ Deferred revenue increased by $47.7 million from $2.1 million at January 1, 2020 to $49.8 million at September 30, 2020. The movement is largely due to the upfront payment of $50.0 million received under the Astellas Collaboration Agreement in January 2020 offset by revenue recognized under our collaboration agreements in the nine months ended September 30, 2020. ​ As of December 31, 2019, there was deferred revenue of $2.1 million associated with the third target under the GSK Collaboration Agreement, of which $0.4 million and $1.5 million was recognized as revenue in the three and nine months ended September 30, 2020 respectively. ​ The Astellas Collaboration Agreement ​ Upon successful completion of the Phase 1 trial for a product, Astellas and Adaptimmune will elect whether to progress with co-development and co-commercialization of such product, or to allow the other party to pursue the candidate independently. If the parties progress with co-development and co-commercialization of a product, then each party will grant the other party a co-exclusive license to co-develop and co-commercialize such product in the field of T-cell therapy. If a product is developed solely by one party, then the other party will grant to the continuing party an exclusive license to develop and commercialize such product in the field of T-cell therapy. ​ In the three months ended June 30, 2020, the parties nominated the target for the first collaboration program and the Company commenced development of this target under the agreement and began recognizing revenue for this performance obligation. ​ In addition, Astellas was also granted the right to develop, independently of Adaptimmune, allogeneic T-cell therapy candidates directed to two targets selected by Astellas. Astellas will have sole rights to develop and commercialize products resulting from these two targets. ​ Under the terms of the agreement, Adaptimmune could be entitled to receive up to $847.5 million in further payments, including: ​ ● Development milestones of up to $73.75 million for each co-developed and co-commercialized product; and ● Development milestones of up to $147.5 million per product and up to $110.0 million in sales milestones for products developed unilaterally by Astellas. ​ In addition, Adaptimmune is entitled to receive research funding of up to $7.5 million per year on a per collaboration target basis, which is payable on a quarterly basis within standard payment terms, and tiered royalties on net sales in the mid-single to mid-teen digits. ​ In consideration for rights under certain contributed Astellas technology for a product unilaterally developed by Adaptimmune, Astellas could be eligible to receive up to $552.5 million, including up to $147.5 million in milestone payments per product, and up to $110.0 million in sales milestones for products developed unilaterally by Adaptimmune. In addition, Astellas is entitled to receive tiered royalties on net sales in the mid-single to mid-teen digits. To the extent that Astellas and Adaptimmune co-develop and co-commercialize any product, the parties would share equally all worldwide costs and profits. Either party can terminate the agreement in the event of material breach or insolvency of the other party. Astellas can terminate the Agreement for convenience in its entirety or partly in relation to any targets and products directed to such targets. Adaptimmune can terminate the Agreement for convenience in relation to any target it is unilaterally developing and to products directed to such target. The Company has assessed the agreement under the provisions of ASC 606, Revenue from Contracts with Customers Collaborative Arrangements The aggregate transaction price at inception of the agreement was the $50.0 million upfront payment. Future development milestones are not considered probable as of September 30, 2020 and have not been included in the transaction price. Reimbursement of the research funding over the co-development period (up until completion of a Phase 1 trial for products directed to such target) is variable consideration and included in the transaction price as of September 30, 2020 to the extent that a significant reversal of revenue is not probable. The Company may also receive sales milestones upon the achievement of specified levels of annual net sales by Astellas under an independent Astellas program. These amounts have not been included within the transaction price as of September 30, 2020 because they are sales-based and would be recognized when the subsequent sales occur. The aggregate transaction price is allocated to the performance obligations depending on the relative standalone selling price of the performance obligations. In determining the best estimate of the standalone selling price, the Company considered internal pricing objectives it used in negotiating the contract, together with internal data regarding the cost and margin of providing research services and adjusted-market data from comparable arrangements. The variable consideration is allocated to the performance obligation to which it relates. The amount of the transaction price allocated to the performance obligation is recognized as or when the Company satisfies the performance obligation. The Company expects to satisfy the performance obligations relating to the three co-development targets as development progresses and recognizes revenue based on an estimate of the percentage of completion of the project determined based on the costs incurred on the project as a percentage of the total expected costs. The Company considers that this depicts the progress of the project, where the significant inputs would be internal project resources and third-party costs. The determination of the percentage of completion requires the Company to estimate the costs-to-complete the project. The Company makes a detailed estimate of the costs-to-complete, which is re-assessed every reporting period based on the latest project plan and discussions with project teams. If a change in facts or circumstances occurs, the estimate will be adjusted and the revenue will be recognized based on the revised estimate. The difference between the cumulative revenue recognized based on the previous estimate and the revenue recognized based on the revised estimate would be recognized as an adjustment to revenue in the period in which the change in estimate occurs. The revenue allocated to the research services will be recognized as development of products directed to the target progresses up until completion of a Phase 1 trial. The Company has determined that the performance obligations relating to the two independent Astellas targets would be recognized at a point-in-time, upon commencement of the licenses in the event of nomination of the target, since they are right-to-use licenses. ​ The amount of the transaction price that is allocated to performance obligations that are unsatisfied or partially satisfied under the agreement as of September 30, 2020 was $62.9 million, of which $14.3 million is allocated to the rights third

Loss per share

Loss per share	9 Months Ended
	Sep. 30, 2020
Loss per share
Loss per share	Note 4 — Loss per share The dilutive effect of 91,263,299 and 90,072,300 stock options outstanding as of September 30, 2020 and 2019 respectively have been excluded from the diluted loss per share calculation for the three and nine months ended September 30, 2020 and 2019, because they would have an antidilutive effect on the loss per share for the period.

Fair value measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2020
Fair value measurements
Fair value measurements	Note 5 — 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 September 30, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value measurements using ​ ​ September 30, ​ Level 1 ​ Level 2 ​ Level 3 ​ 2020 ​ ​ ​ ​ ​ ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 315,437 $ 315,437 ​ — ​ — Agency bonds ​ ​ 6,005 ​ ​ ​ ​ ​ 6,005 ​ ​ — ​ $ 321,442 $ 315,437 $ 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	9 Months Ended
	Sep. 30, 2020
Marketable securities - available-for-sale debt securities
Marketable securities - available-for-sale debt securities	Note 6 — Marketable securities – available-for-sale debt securities As of September 30, 2020, 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 ​ $ 14,272 ​ $ 16 ​ $ (4) ​ $ 14,284 Corporate debt securities ​ 3 months to 1 year ​ ​ 164,830 ​ ​ 336 ​ ​ (40) ​ ​ 165,126 Agency bonds ​ 1 year to 2 years ​ ​ 5,996 ​ ​ 9 ​ ​ — ​ ​ 6,005 Corporate debt securities ​ 1 year to 2 years ​ ​ 136,058 ​ ​ 107 ​ ​ (138) ​ ​ 136,027 ​ ​ $ 321,156 ​ $ 468 ​ $ (182) ​ $ 321,442 ​ As of September 30, 2020 and December 31, 2019, the aggregate fair value of securities held by the Company in an unrealized loss position was $135.0 million and $2.0 million respectively, which consisted of 23 and 1 separate securities, respectively. No securities have been in an unrealized loss position for more than one year. As of September 30, 2020, 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. 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	9 Months Ended
	Sep. 30, 2020
Other current assets
Other current assets	Note 7 — Other current assets Other current assets consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2020 2019 Corporate tax receivable $ 13,921 $ 19,284 Prepayments ​ 7,754 ​ 8,395 Clinical materials ​ 2,488 ​ 1,459 Other current assets ​ 2,662 ​ 1,809 ​ ​ $ 26,825 ​ $ 30,947 ​

Accrued expenses and other curr

Accrued expenses and other current liabilities	9 Months Ended
	Sep. 30, 2020
Accrued expenses and other current liabilities
Accrued expenses and other current liabilities	Note 8 — Accrued expenses and other current liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2020 2019 Accrued clinical and development expenditure ​ $ 11,097 ​ $ 8,782 Accrued employee expenses ​ ​ 8,127 ​ ​ 6,863 Other accrued expenditure ​ ​ 2,784 ​ ​ 2,662 Accrued purchase commitments ​ ​ 2,500 ​ ​ 5,000 Other ​ 107 ​ 56 ​ ​ $ 24,615 ​ $ 23,363 ​ In 2016, the Company entered into a supply agreement with ThermoFisher for the supply of the Dynabeads® CD3/CD28 technology. The supply agreement runs until December 31, 2025. Under the supply agreement, the Company is required to purchase its requirements for CD3/CD28 magnetic bead product exclusively from ThermoFisher for a period of 5 years. In the three months ended September 30, 2019, management considered that there was sufficient uncertainty surrounding the utility of the Dynabeads to result in $5.0 million of minimum purchasing obligations being recognized in in research and development expense in that period. The related per-share amount for both the three and nine months ended September 30, 2019 is $(0.01). Of the minimum purchasing obligations of $5.0 million, $2.5 million was paid during the nine-months ended September 30, 2020. The remaining minimum purchase obligations of $2.5 million are payable within the next year, and are included within accrued purchase commitments above.

Share-based compensation

Share-based compensation	9 Months Ended
	Sep. 30, 2020
Share-based compensation
Share-based compensation	Note 9 — 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 ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ 2020 2019 2020 2019 ​ ​ Research and development ​ $ 1,219 ​ $ 144 ​ $ 3,126 ​ $ 2,951 ​ ​ General and administrative ​ 2,061 ​ 1,676 ​ 4,226 ​ ​ 5,544 ​ ​ ​ ​ $ 3,280 ​ $ 1,820 ​ $ 7,352 ​ $ 8,495 ​ ​ ​ ​ ​ 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 ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2020 2019 2020 2019 ​ Number of options over ordinary shares granted ​ ​ 1,882,966 ​ ​ 3,733,359 ​ ​ 14,851,182 ​ ​ 15,477,255 ​ Weighted average fair value of ordinary shares options ​ $ 1.25 ​ $ 0.31 ​ $ 0.57 ​ $ 0.48 ​ Number of additional options with a nominal exercise price granted ​ ​ 571,320 ​ ​ 743,292 ​ ​ 7,410,136 ​ ​ 7,700,658 ​ Weighted average fair value of options with a nominal exercise price ​ $ 1.70 ​ ​ 0.51 ​ $ 0.78 ​ $ 0.89 ​ ​

Stockholders' equity

Stockholders' equity	9 Months Ended
	Sep. 30, 2020
Stockholders' equity
Stockholders' equity	Note 10 — Stockholders’ equity On January 24, 2020, the Company closed an underwritten public offering of 21,000,000 American Depository Shares (ADSs), which together with the full exercise by the underwriters of their option to purchase an additional 3,150,000 ADSs, generated net proceeds of $90.5 million. On June 4, 2020, the Company closed an underwritten public offering of 23,575,000 ADSs, which together with the full exercise by the underwriters of their option to purchase an additional 3,075,000 ADSs, generated net proceeds of $243.8 million. ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
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 27, 2020 (the “Annual Report”). The balance sheet as of December 31, 2019 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 interim 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 the valuation of share options, valuation allowances relating to deferred tax assets, revenue recognition, estimation of the incremental borrowing rate for operating leases, estimating clinical trial expenses and estimating R&D tax and expenditure credits. 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 Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract On January 1, 2020, the Company adopted ASU 2018-15 – Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The guidance aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The Company elected to apply the guidance prospectively to all implementation costs incurred after the date of adoption. The guidance has not had a material effect on the condensed consolidated financial statements. Simplifying the Accounting for Income Taxes On January 1, 2020, the Company adopted ASU 2019-12 – Simplifying the Accounting for Income Taxes (Topic 740). The simplifications to accounting for income taxes cover a variety of areas, including the removal of the exception to the incremental approach for intraperiod tax allocation when there is a loss from continuing operations and income or a gain from other items (for example, discontinued operations or other comprehensive income). The changes also add a requirement for an entity to reflect the effect of an enacted change in tax laws or rates in the annual effective tax rate computation in the interim period that includes the enactment date. Most of the amendments should be applied on a prospective basis. The guidance has not had a material effect on the condensed consolidated financial statements. Changes to the Disclosure Requirements for Fair Value Measurement On January 1, 2020, the Company adopted ASU 2018-13 – Fair Value Measurement (Topic 820) - Disclosure Framework— Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. Certain amendments apply prospectively with all other amendments applied retrospectively to all periods presented upon their effective date. The guidance has not had a material effect on the condensed consolidated financial statements. Revenue Recognition in Collaborative Arrangements On January 1, 2020, the Company adopted ASU 2018-18 – Collaborative Arrangements — Clarifying the Interaction between Topic 808 and Topic 606, which clarifies that certain transactions between collaborative arrangement participants should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account. In those situations, all the guidance in Topic 606 should be applied, including recognition, measurement, presentation, and disclosure requirements. The guidance has been applied retrospectively to all contracts that were not completed at the date of initial application of Topic 606. The guidance has not had a material effect on the condensed consolidated financial statements because it did not change the Company’s accounting for existing or previous collaborative arrangements. ​ 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 to the fiscal year beginning January 1, 2023. The Company currently intends to adopt the guidance in the fiscal year beginning January 1, 2023. 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)	9 Months Ended
	Sep. 30, 2020
Revenue
Summary of revenue categories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended Nine months ended ​ September 30, ​ September 30, ​ 2020 2019 ​ 2020 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Development revenue $ 1,193 $ 237 ​ $ 2,456 $ 394 ​ $ 1,193 $ 237 ​ $ 2,456 $ 394

Fair value measurements (Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value measurements using ​ ​ September 30, ​ Level 1 ​ Level 2 ​ Level 3 ​ 2020 ​ ​ ​ ​ ​ ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate debt securities $ 315,437 $ 315,437 ​ — ​ — Agency bonds ​ ​ 6,005 ​ ​ ​ ​ ​ 6,005 ​ ​ — ​ $ 321,442 $ 315,437 $ 6,005 $ —

Marketable securities - avail_2

Marketable securities - available-for-sale debt securities (Tables)	9 Months Ended
	Sep. 30, 2020
Marketable securities - available-for-sale debt securities
Schedule of investments in marketable securities	As of September 30, 2020, 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 ​ $ 14,272 ​ $ 16 ​ $ (4) ​ $ 14,284 Corporate debt securities ​ 3 months to 1 year ​ ​ 164,830 ​ ​ 336 ​ ​ (40) ​ ​ 165,126 Agency bonds ​ 1 year to 2 years ​ ​ 5,996 ​ ​ 9 ​ ​ — ​ ​ 6,005 Corporate debt securities ​ 1 year to 2 years ​ ​ 136,058 ​ ​ 107 ​ ​ (138) ​ ​ 136,027 ​ ​ $ 321,156 ​ $ 468 ​ $ (182) ​ $ 321,442

Other current assets (Tables)

Other current assets (Tables)	9 Months Ended
	Sep. 30, 2020
Other current assets
Summary of other current assets	Other current assets consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2020 2019 Corporate tax receivable $ 13,921 $ 19,284 Prepayments ​ 7,754 ​ 8,395 Clinical materials ​ 2,488 ​ 1,459 Other current assets ​ 2,662 ​ 1,809 ​ ​ $ 26,825 ​ $ 30,947

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
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): ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2020 2019 Accrued clinical and development expenditure ​ $ 11,097 ​ $ 8,782 Accrued employee expenses ​ ​ 8,127 ​ ​ 6,863 Other accrued expenditure ​ ​ 2,784 ​ ​ 2,662 Accrued purchase commitments ​ ​ 2,500 ​ ​ 5,000 Other ​ 107 ​ 56 ​ ​ $ 24,615 ​ $ 23,363

Share-based compensation (Table

Share-based compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based compensation
Summary of share-based compensation expense included in the unaudited 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 ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ 2020 2019 2020 2019 ​ ​ Research and development ​ $ 1,219 ​ $ 144 ​ $ 3,126 ​ $ 2,951 ​ ​ General and administrative ​ 2,061 ​ 1,676 ​ 4,226 ​ ​ 5,544 ​ ​ ​ ​ $ 3,280 ​ $ 1,820 ​ $ 7,352 ​ $ 8,495 ​ ​
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 ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2020 2019 2020 2019 ​ Number of options over ordinary shares granted ​ ​ 1,882,966 ​ ​ 3,733,359 ​ ​ 14,851,182 ​ ​ 15,477,255 ​ Weighted average fair value of ordinary shares options ​ $ 1.25 ​ $ 0.31 ​ $ 0.57 ​ $ 0.48 ​ Number of additional options with a nominal exercise price granted ​ ​ 571,320 ​ ​ 743,292 ​ ​ 7,410,136 ​ ​ 7,700,658 ​ Weighted average fair value of options with a nominal exercise price ​ $ 1.70 ​ ​ 0.51 ​ $ 0.78 ​ $ 0.89 ​

General (Details)

General (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
General
Accumulated deficit	$ 549,143	$ 455,664

Revenue - Revenue from contract

Revenue - Revenue from contracts with customers (Details) $ in Thousands	Jan. 13, 2020USD ($)	Jan. 01, 2020USD ($)	Sep. 30, 2020USD ($)customer	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)customer	Sep. 30, 2019USD ($)
Revenue
Number of customers | customer			2		2
Revenue			$ 1,193	$ 237	$ 2,456	$ 394
Revenue recognized in the period			400		1,500
Increase in deferred revenue		$ 47,700			48,649	2,824
Deferred revenue		$ 2,100	49,800		49,800
Development revenue
Revenue
Revenue			$ 1,193	$ 237	$ 2,456	$ 394
Astellas Collaboration Agreement
Revenue
Upfront payment received	$ 50,000

Revenue - Collaboration Agreeme

Revenue - Collaboration Agreement - The Astellas Collaboration Agreement (Details) - Astellas Collaboration Agreement $ in Thousands	Jan. 13, 2020USD ($)item	Sep. 30, 2020item
Collaboration and License Agreement
Upfront payment received	$ 50,000
Number Of Co Development Target | item	3
Number of independent targets | item	2	2
Maximum
Collaboration and License Agreement
Potential milestone payments to be received	$ 847,500
Research funding the entity is entitled to receive per year on a per collaboration target basis	7,500
Potential milestone payments to be paid	552,500
Development milestone for each co-developed and co-commercialized product | Maximum
Collaboration and License Agreement
Potential milestone payments to be received	73,750
Development milestone per product developed unilaterally | Maximum
Collaboration and License Agreement
Potential milestone payments to be received	147,500
Sales milestone for products developed unilaterally | Maximum
Collaboration and License Agreement
Potential milestone payments to be received	110,000
Milestone Per Product Developed By Entity | Maximum
Collaboration and License Agreement
Potential milestone payments to be paid	147,500
Sales Milestone Per Product Developed By Entity | Maximum
Collaboration and License Agreement
Potential milestone payments to be paid	$ 110,000

Revenue - Collaboration Agree_2

Revenue - Collaboration Agreement - Performance obligations (Details) - Astellas Collaboration Agreement $ in Millions	Jan. 13, 2020USD ($)item	Sep. 30, 2020USD ($)item
Performance obligations
Number of co-development targets | item	3
Number of independent targets | item	2	2
Amount of transaction price of the agreement at inception	$ 50
Amount of transaction price allocated to performance obligation that has not been recognized as revenue		$ 62.9
Rights granted, first independent target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue		14.3
Rights granted, second independent target
Performance obligations
Amount of transaction price allocated to performance obligation that has not been recognized as revenue		14.3
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		20.5
Rresearch 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		6.9
Rresearch 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		$ 6.9

Loss per share - Antidilutive s

Loss per share - Antidilutive shares (Details) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Share options
Antidilutive securities
Potentially dilutive equity instruments excluded from the diluted loss per share (in shares)	91,263,299	90,072,300

Fair value measurements (Detail

Fair value measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	$ 321,442	$ 39,130
Recurring basis
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	321,442
Recurring basis | Corporate debt securities
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	315,437
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	315,437
Recurring basis | Level 1 | Corporate debt securities
Marketable securities:
Available-for-sale securities, Debt Securities, Current, Total	315,437
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	Sep. 30, 2020USD ($)security	Dec. 31, 2019USD ($)security
Marketable securities
Fair market value of investments in an unrealized loss position	$ 135,000	$ 2,000
Number of debt securities | security	23	1
Number of available-for-sale securities in an unrealized loss position for more than one year | security	0
Debt Securities
Marketable securities
Amortized cost	$ 321,156
Gross unrealized gains	468
Gross unrealized losses	(182)
Aggregate estimated fair value	321,442
Corporate Debt Securities Maturity Period Less Than Three Months | Debt Securities
Marketable securities
Amortized cost	14,272
Gross unrealized gains	16
Gross unrealized losses	(4)
Aggregate estimated fair value	14,284
Corporate Debt Securities Maturity Period Three Months To One Year
Marketable securities
Amortized cost	164,830
Gross unrealized gains	336
Gross unrealized losses	(40)
Aggregate estimated fair value	165,126
Corporate Debt Securities Maturity Period One Year To Two Years | Debt Securities
Marketable securities
Amortized cost	136,058
Gross unrealized gains	107
Gross unrealized losses	(138)
Aggregate estimated fair value	136,027
Agency Bond Maturity Period One Year To Two Years | Debt Securities
Marketable securities
Amortized cost	5,996
Gross unrealized gains	9
Aggregate estimated fair value	$ 6,005

Other current assets (Details)

Other current assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other current assets
Corporate tax receivable	$ 13,921	$ 19,284
Prepayments	7,754	8,395
Clinical materials	2,488	1,459
Other current assets	2,662	1,809
Total	$ 26,825	$ 30,947

Accrued expenses and other cu_3

Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accrued expenses and other current liabilities
Accrued clinical and development expenditure	$ 11,097	$ 8,782
Accrued employee expenses	8,127	6,863
Other accrued expenditure	2,784	2,662
Accrued purchase commitments	2,500	5,000
Other	107	56
Total	$ 24,615	$ 23,363

Accrued expenses and other cu_4

Accrued expenses and other current liabilities - Supply agreement (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Contingencies and commitments
Required purchase period			5 years
Losses accrued on firm purchase commitments	$ 0	$ 5,000	$ 0	$ 5,000
Related per share amount		$ (0.01)		$ (0.01)
Research and development
Contingencies and commitments
Purchasing obligations	2,500	$ 5,000	2,500	$ 5,000
Purchase Obligation, Due in Next Twelve Months	$ 2,500		$ 2,500

Share-based compensation - Shar

Share-based compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	$ 3,280	$ 1,820	$ 7,352	$ 8,495
Research and development
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	1,219	144	3,126	2,951
General and administrative
Total share-based compensation expense included in the consolidated statements of operations
Total share-based compensation expense	$ 2,061	$ 1,676	$ 4,226	$ 5,544

Share-based compensation - Opti

Share-based compensation - Options (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based compensation
Number of options granted (in shares)	1,882,966	3,733,359	14,851,182	15,477,255
Weighted average fair value (in dollars per share)	$ 1.25	$ 0.31	$ 0.57	$ 0.48
Number of additional options with a nominal exercise price granted	571,320	743,292	7,410,136	7,700,658
Weighted average fair value of RSU-style options granted	$ 1.70	$ 0.51	$ 0.78	$ 0.89

Stockholders' equity - Underwri

Stockholders' equity - Underwritten public offering and Registered direct offering (Details) - American Depository Shares (ADSs) - USD ($) $ in Millions	Jun. 04, 2020	Jan. 24, 2020
Stockholders' equity
Issuance of common stock (in shares)	3,075,000	21,000,000
Net proceeds	$ 243.8	$ 90.5
Underwritten public offering
Stockholders' equity
Issuance of common stock (in shares)	23,575,000
Over-Allotment Option
Stockholders' equity
Issuance of common stock (in shares)		3,150,000