Cellectis (CLLS) 20-F 5 Mar 20 2019 FY Annual report (foreign) Financial data

Cover Page

Cover Page	12 Months Ended
	Dec. 31, 2019shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	CELLECTIS S.A.
Entity Central Index Key	0001627281
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	42,465,669
Entity Shell Company	false
Entity Emerging Growth Company	false
Document Transition Report	false
Document Annual Report	true
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Address, Country	FR
Document Shell Company Report	false
American Depositary Shares [member]
Document Information [Line Items]
Trading Symbol	CLLS
Title of 12(b) Security	American Depositary Shares, each representing one ordinary share, nominal value €0.05 per share
Security Exchange Name	NASDAQ

Statements of Consolidated Fina

Statements of Consolidated Financial Position - USD ($) $ in Thousands	Dec. 31, 2019	[1]	Jan. 01, 2019	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Non-current assets
Intangible assets	$ 1,108		$ 1,268	$ 1,268		$ 1,431		$ 1,343
Property, plant, and equipment	23,712		8,732	10,041		7,226		16,900
Right-of-use assets	45,612		37,569
Other non-current financial assets	5,517		1,891	1,891		300
Total non-current assets	75,949		49,460	13,199
Current assets
Inventories	2,897		275	275
Trade receivables	2,959		2,971	2,971
Subsidies receivables	9,140		17,173	17,173
Other current assets	15,617		13,194	15,333
Current financial assets	20,385		388	388
Cash and cash equivalents	340,522		451,501	451,501	[1]	256,380		254,568
Total current assets	391,520		485,502	487,641
TOTAL ASSETS	467,469		534,961	500,840
Shareholders' equity
Share capital	2,767		2,765	2,765
Premiums related to the share capital	843,478		828,525	828,525
Currency translation adjustment	(22,641)		(16,668)	(16,668)
Retained deficit	(406,390)		(326,628)	(326,628)
Net income (loss)	(102,091)		(78,693)	(78,693)
Total shareholders' equity - Group Share	315,123		409,301	409,301
Non-controlling interests	40,347		40,970	40,970
Total shareholders' equity	355,470		450,272	450,272	[2]	$ 283,986	[2],[3]	$ 272,984	[2],[3]
Non-current liabilities
Non-current lease debts	46,540		32,737	1,018
Non-current provisions	2,855		2,042	2,681
Total non-current liabilities	49,395		34,779	3,699
Current liabilities
Current lease debts	1,067		4,076	333
Trade payables	29,264		15,883	15,883
Deferred revenues and contract liabilities	20,033		20,454	20,754
Current provisions	3,743		1,127	1,530
Other current liabilities	8,497		8,369	8,369
Total current liabilities	62,604		49,910	46,869
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 467,469		$ 534,961	$ 500,840
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.
[2]	Corresponds to the impact of Calyxt stock options exercises during the period.
[3]	Reflects the application of IFRS15 with effect from January 1, 2018 using the full retrospective method.

Statements of Consolidated Oper

Statements of Consolidated Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Profit or loss [abstract]
Revenues	$ 15,190	[1]	$ 12,731	$ 25,188
Other income	7,800	[1]	8,701	8,528
Total revenues and other income	22,990	[1]	21,432	33,715
Operating expenses
Cost of revenue	(11,392)	[1]	(2,739)	(2,620)
Research and development expenses	(92,042)	[1]	(76,567)	(79,227)
Selling, general and administrative expenses	(43,017)	[1]	(47,248)	(44,750)
Other operating income (expenses)	(91)	[1]	31	232
Total operating expenses	(146,542)	[1]	(126,523)	(126,366)
Operating income (loss)	(123,552)	[1]	(105,091)	(92,650)
Financial income	11,971	[1]	20,572	7,262
Financial expenses	(3,631)	[1]	(3,813)	(18,294)
Financial gain (loss)	8,340	[1]	16,758	(11,032)
Income tax	0
Net income (loss)	(115,212)	[1]	(88,333)	(103,683)
Attributable to shareholders of Cellectis	(102,091)	[1]	(78,693)	(99,368)
Attributable to non-controlling interests	$ (13,121)	[1]	$ (9,640)	$ (4,315)
Basic / Diluted net income (loss) per share attributable to shareholders of Cellectis
Basic net income (loss) attributable to shareholders of Cellectis per share ($ /share)	$ (2.41)	[1]	$ (1.93)	$ (2.78)
Diluted net income (loss) attributable to shareholders of Cellectis per share ($ /share)	$ (2.41)	[1]	$ (1.93)	$ (2.78)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Statement of comprehensive income [abstract]
Net income (loss)	$ (115,212)	[1]	$ (88,333)	$ (103,683)
Actuarial gains and losses	(303)		70	(515)
Other comprehensive income (loss) that will not be reclassified subsequently to income or loss	(303)		70	(515)
Currency translation adjustment	(5,714)		(19,192)	23,512
Commodity derivative contracts	17
Other comprehensive income (loss) that will be reclassified subsequently to income or loss	(5,697)		(19,192)	23,512
Total Comprehensive income (loss)	(121,212)		(107,455)	(80,686)
Attributable to shareholders of Cellectis	(108,356)		(97,125)	(75,963)
Attributable to non-controlling interests	$ (12,856)		$ (10,330)	$ (4,723)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Statements of Consolidated Cash

Statements of Consolidated Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Cash flows from operating activities
Net loss for the period		$ (115,212)	[1]	$ (88,333)		$ (103,683)
Reconciliation of net loss and of the cash provided by (used in) operating activities
Amortization and depreciation		6,875	[1]	2,377		3,371
Net loss (income) on disposals		15	[1]	20		40
Net financial loss (gain)		(8,340)	[1]	(16,758)		11,032
Expenses related to share-based payments		26,880	[1]	37,218		50,418
Provisions		2,093	[1]	(468)		2,908
Other non cash items		85	[1]			2
Interest (paid) / received		6,808	[1]	6,905		1,371
Operating cash flows before change in working capital		(80,796)	[1]	(59,040)		(34,540)
Decrease (increase) in inventories		(2,627)	[1]	(37)		(109)
Decrease (increase) in trade receivables and other current assets		(2,674)	[1]	(3,696)		(549)
Decrease (increase) in subsidies receivables		7,359	[1]	(8,257)		305
(Decrease) increase in trade payables and other current liabilities		9,635	[1]	9,374		(335)
(Decrease) increase in deferred income		(39)	[1]	(6,480)		(17,099)
Change in working capital		11,654	[1]	(9,096)		(17,787)
Net cash flows provided by (used in) operating activities		(69,142)	[1]	(68,137)		(52,327)
Cash flows from investing activities
Proceeds from disposal of property, plant and equipment		414	[1]	1,262		7,164
Acquisition of intangible assets		(45)	[1]	(171)		(273)
Acquisition of property, plant and equipment		(12,913)	[1]	(4,715)		(2,383)
Net change in non-current financial assets		(3,636)	[1]	221		(125)
Sale (Acquisition) of current financial assets		(19,692)	[1]	39,025		(2,598)
Net cash flows provided by (used in) investing activities		(35,872)	[1]	35,623		1,784
Cash flows from financing activities
Increase in share capital net of transaction costs		0	[1]	186,382		2,930
Shares of Calyxt issued to / (purchased from) third parties		(469)	[1]	49,942		38,257
Decrease in borrowings		0	[1]	(127)		(41)
Payments on lease debts	[1]	(3,393)
Treasury shares		0	[1]	297		120
Net cash flows provided by (used in) financing activities		(3,862)	[1]	236,494		41,266
(Decrease) increase in cash and cash equivalents		(108,876)	[1]	203,981		(9,277)
Cash and cash equivalents at the beginning of the year		451,501	[1]	256,380		254,568
Effect of exchange rate changes on cash		(2,103)	[1]	(8,860)		11,089
Cash and cash equivalents at the end of the period		$ 340,522	[1]	$ 451,501	[1]	$ 256,380
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Statements of Changes in Consol

Statements of Changes in Consolidated Shareholders' Equity - USD ($) $ in Thousands		Total		Share Capital Ordinary Shares [member]	Premiums Related to Share Capital [member]	Treasury Shares [member]	Currency Translation Adjustment [member]	Retained Earnings (Deficit) [member]	Income (Loss) [member]	Attributable to Shareholders of Cellectis [member]	Non controlling Interests [member]
Beginning balance at Dec. 31, 2016	[1],[2]	$ 272,984		$ 2,332	$ 568,185	$ (416)	$ (22,085)	$ (209,651)	$ (67,255)	$ 271,109	$ 1,876
Beginning balance, shares at Dec. 31, 2016	[1],[2]			35,335,060
Statement [Line Items]
Net Loss		(103,683)							(99,368)	(99,368)	(4,315)
Other comprehensive income (loss)		22,997					23,920	(515)		23,405	(408)
Total Comprehensive income (loss)		(80,686)					23,920	(515)	(99,368)	(75,963)	(4,723)
Allocation of prior period loss								(67,255)	67,255
Capital Increase				$ 26				(26)
Capital Increase, Shares				466,950
Transaction with subsidiaries	[3]	38,257						23,747		23,747	14,510
Treasury shares		120				120				120
Exercise of share warrants and employee warrants		2,930			2,921					2,930
Exercise of share warrants and employee warrants, amount				$ 9
Exercise of share warrants and employee warrants, shares				158,052
Other movements		(38)			(37)			(1)		(38)
Balance at end of year at Dec. 31, 2017	[1],[2]	283,986		$ 2,367	614,037	(297)	1,835	(253,702)	(99,368)	264,873	19,113
Ending balance, shares at Dec. 31, 2017	[1],[2]			35,960,062
Statement [Line Items]
Non-cash stock-based compensation expense		50,418			42,968					42,968	7,450
Net Loss		(88,333)							(78,693)	(78,693)	(9,640)
Other comprehensive income (loss)		(19,122)					(18,502)	70		(18,432)	(690)
Total Comprehensive income (loss)		(107,455)					(18,502)	70	(78,693)	(97,125)	(10,330)
Allocation of prior period loss								(99,368)	99,368
Capital Increase		178,611		$ 379	178,230			2		178,611
Capital Increase, Shares				6,146,000
Transaction with subsidiaries	[4]	49,942						26,454		26,454	23,488
Treasury shares		239				$ 297		(58)		239
Exercise of share warrants and employee warrants		7,770			7,751					7,770
Exercise of share warrants and employee warrants, amount				$ 19
Exercise of share warrants and employee warrants, shares				324,007
Other movements		(40)						(28)		(28)	(12)
Balance at end of year at Dec. 31, 2018	[1]	450,272		$ 2,765	828,525		(16,668)	(326,628)	(78,693)	409,301	40,970
Ending balance, shares at Dec. 31, 2018	[1]			42,430,069
Statement [Line Items]
Non-cash stock-based compensation expense		37,218			28,507					28,507	8,711
Net Loss		(115,212)	[5]						(102,091)	(102,091)	(13,121)
Other comprehensive income (loss)		(6,000)					(5,972)	(292)		(6,265)	265
Total Comprehensive income (loss)		(121,212)					(5,972)	(292)	(102,091)	(108,356)	(12,856)
Allocation of prior period loss								(78,693)	78,693
Capital Increase				$ 2				(2)
Capital Increase, Shares				35,600
Transaction with subsidiaries	[4]	(469)						(773)		(773)	304
Exercise of share warrants and employee warrants, amount				$ 0
Other movements				0	2			(2)
Balance at end of year at Dec. 31, 2019		355,470	[5]	$ 2,767	843,478		$ (22,641)	$ (406,390)	$ (102,091)	315,123	40,347
Ending balance, shares at Dec. 31, 2019				42,465,669
Statement [Line Items]
Non-cash stock-based compensation expense		$ 26,879			$ 14,951					$ 14,950	$ 11,929
[1]	Corresponds to the impact of Calyxt stock options exercises during the period.
[2]	Reflects the application of IFRS15 with effect from January 1, 2018 using the full retrospective method.
[3]	Net proceeds to Calyxt from the Calyxt IPO of $58.0 million after deduction of $3.1 million of underwriting discounts and commissions and $3.3 million of other offering expenses. Equity of Calyxt attributable to non-controlling interests of 20.3% was $11.8 million and equity of Calyxt attributable to Cellectis of 79.3% is $26.4 million (after consideration of Cellectis’ investment in shares of Calyxt issued as part of the Calyxt IPO for a purchase price of $20 million).
[4]	On May 22, 2018, Calyxt Inc completed a follow-on offering of its common stock. Calyxt Inc sold an aggregate of 4,057,500 shares of common stock at a price of $15.00 per share, including 457,500 shares of common stock pursuant to the exercise of the underwriters’ option to purchase additional shares. In the aggregate, Calyxt Inc received net proceeds from the follow-on offering and exercise of the overallotment option of approximately $57.0 million, after deducting underwriting discounts and commissions of $3.2 million and offering expenses totaling approximately $0.7 million. As part of the follow-on offering, Cellectis SA purchased 550,000 shares of common stock for a value of $8.3 million. Transaction with subsidiaries also includes the exercise of 592,342 Calyxt stock options during the period for $2.4 million, partially offset by Cellectis’ purchase on June 14, 2018 of 63,175 shares of Calyxt common stock from employees and nonemployees of Calyxt and Cellectis at a price of $19.49 per share (the closing price reported on the Nasdaq Global Market on June 14, 2018) for $1.2 million.
[5]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Statements of Changes in Cons_2

Statements of Changes in Consolidated Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	Jun. 14, 2018	Dec. 31, 2017
Calyxt Inc [member]
Statement [Line Items]
Gross proceeds		$ 58,000
Underwriting discounts and commissions		3,100
Other offering expense		$ 3,300
Non-controlling shareholders interest		20.30%
Number of stock options exercised	592,342
Equity value		$ 11,800
Stock options exercised, value	$ 2,400
Purchase price		$ 20,000
Calyxt Inc [member] | Cellectis [member]
Statement [Line Items]
Percentage of interest attributable to parent		79.30%
Equity value		$ 26,400
Purchase of common shares	63,175
Purchase of common shares price per share	$ 19.49
Purchase of common stock, value	$ 1,200,000

The Company

The Company	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
The Company	Note 1. The Company Cellectis S.A. (hereinafter “Cellectis” or “we”) is a limited liability company (“société anonyme”) registered and domiciled in Paris, France. We are a clinical-stage biotechnological company, employing our core proprietary technologies to develop best-in-class T-cells T-cells, Cellectis S.A., Cellectis, Inc., Cellectis Biologics Inc. (which was incorporated on January 18, 2019) and Calyxt, Inc. are sometimes referred to as a consolidated group of companies as the “Group.”

Accounting principles

Accounting principles	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Accounting principles	Note 2. Accounting principles 2.1 Basis for preparation The Consolidated Financial Statements of Cellectis as of and for the year ended December 31, 2019 were approved by our Board of Directors on March 4, 2020. Our Consolidated Financial Statements are presented in U.S. dollars. See Note 2.4. The Consolidated Financial Statements have been prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”) and in accordance The Consolidated Financial Statements have been prepared using the historical cost measurement basis except for certain assets and liabilities that are measured at fair value in accordance with IFRS. IFRS include International Financial Reporting Standards (“IFRS”), International Accounting Standards (“the IAS”), as well as the interpretations issued by the Standards Interpretation Committee (“the SIC”), and the International Financial Reporting Interpretations Committee (“IFRIC”). The significant accounting methods used to prepare the Consolidated Financial Statements are described below. Application of new or amended standards or new amendments The following pronouncements and related amendments have been adopted by us from January 1, 2019 but had no significant impact on the Consolidated Financial Statements: • Amendment to IFRS 9 “Financial Instruments – Prepayment Features with Negative Compensation” (applicable for periods beginning after January 1, 2019) • IFRIC 23 “Uncertainty over Income Tax Treatments” (applicable for periods beginning after January 1, 2019) • Amendment to IAS 28 “Long-term Interests in Associates and Joint Ventures” (applicable for periods beginning after January 1, 2019) • Amendment to IAS 19 “Plan Amendment, Curtailment or Settlement” (applicable for periods beginning after January 1, 2019) • Annual Improvements to IFRSs 2015–2017 Cycle (Amendments to IFRS 3, IFRS 11, IAS 12 and IAS 23, applicable for periods beginning after January 1, 2019) Standards, interpretations and amendments issued but not yet effective The following pronouncements and related amendments are applicable for first quarter accounting periods beginning after January 1, 2020. We do not anticipate that the adoption of these pronouncements and amendments will have a material impact on our results of operations, financial position or cash flows. • Amendments to References to the Conceptual Framework in IFRS Standards (Effective for the accounting periods as of January 1, 2020) • Amendment to IFRS 3 “Business Combinations” (Effective for the accounting periods as of January 1, 2020 and not yet adopted by the European Union) • Amendments to IAS 1 “Presentation of financial statements” and IAS 8 “Accounting policies, changes in accounting estimates and errors” (Effective for the accounting periods as of January 1, 2020) • Amendements to IFRS 9 “Financial instruments”, IAS 39 “Financial instruments: Recognition and Measurement” et IFRS 7 “Financial instruments: Disclosures” (Effective for the accounting periods as of January 1, 2020) - Interest Rate Benchmark Reform • IFRS 17 “Insurance Contracts” (applicable for periods beginning after January 1, 2021 and not yet adopted by the European Union) 2.2 IFRS16 application Since January 1, 2019, Cellectis has applied the new standard IFRS 16 “Leases”. Under this standard, a financial asset and a financial liability are recognized for Group leases that meet the standard’s criteria. The financial statements for prior periods have not been restated in accordance with the transition options of IFRS 16 elected by the Group since Cellectis has applied the modified retrospective approach. The Group uses the two capitalization exemptions provided by the standard: • lease contracts with a duration of less than 12 months ; • lease contracts for which the underlying asset has a low value, which has been defined by the Group to be below $5,000. The Group has also applied the following practical expedients at the transition date: • exclusion of initial direct costs from the measurement of the • accounting for leases for which the lease term ends within 12 months of the date of initial application as short-term leases • the carrying amount of the right-of-use The following discount rates have been applied: • building rental in Paris, France (discounting rate 2%), building rental in Roseville, Minnesota, USA and Raleigh, North Carolina, USA (discounting rate of 8%), building rental in New York, New York, USA (discounting rate of 4.4%), and equipment rental (discounting rate 1%). The main changes introduced by IFRS 16 are the following: Capitalization of the right-of-use Identified lease contracts mainly concern Cellectis’ Headquarters and R&D buildings in Paris, New York and Raleigh, North Carolina, USA and Calyxt’s Headquarters and its production and storage areas in Roseville, Minnesota, USA. For purposes of IFRS 16, the lease term reflects the Group’s reasonable expectation of the period during which the underlying asset will be used. The discount rate used to calculate the lease debt has been determined, for each portfolio of assets, according to the incremental borrowing rate at the transition date. The sale and lease-back agreement entered into by Calyxt in the third quarter of 2017 has a defined lease term and was classified as an operating lease agreement under IAS 17. According to IFRS 16, this lease receives the standard accounting treatment for operating leases existing at the date of initial application and the value of the right-of-use Accounting for the other assets leases: The main lease contracts identified correspond to office and laboratory equipment. The cumulative effect of initially applying IFRS 16 has been recognized as an adjustment to the opening balance sheet at the date of initial application, January 1, 2019, as presented in the table below: January 1, 2019 as IFRS 16 January 1, 2019 ASSETS Non-current Intangible assets 1,268 1,268 Property, plant, and equipment 10,041 (1,309 ) 8,732 Right-of-use — 37,569 37,569 Other non-current 1,891 1,891 Total non-current 13,199 36,260 49,460 Current assets Inventories 275 275 Trade receivables 2,971 2,971 Subsidies receivables 17,173 17,173 Other current assets 15,333 (2,139 ) 13,194 Current financial assets 388 388 Cash and cash equivalents 451,501 451,501 Total current assets 487,641 (2,139 ) 485,502 TOTAL ASSETS 500,840 34,121 534,961 LIABILITIES Shareholders’ equity Share capital 2,765 2,765 Premiums related to the share capital 828,525 828,525 Treasury share reserve — — Currency translation adjustment (16,668 ) (16,668 ) Retained earnings (deficit) (326,628 ) (326,628 ) Net income (loss) (78,693 ) (78,693 ) Total shareholders’ equity - Group Share 409,301 409,301 Non-controlling 40,970 40,970 Total shareholders’ equity 450,272 450,272 Non-current Non-current 1,018 31,720 32,737 Non-current 2,681 (639 ) 2,042 Total non-current 3,699 31,081 34,779 Current liabilities Current lease debts 333 3,743 4,076 Trade payables 15,883 15,883 Deferred revenues and contract liabilities 20,754 (299 ) 20,454 Current provisions 1,530 (403 ) 1,127 Other current liabilities 8,369 8,369 Total current liabilities 46,869 3,041 49,910 TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY 500,840 34,121 534,961 The rental charges relating to these leases – i.e. $4.0 million for the year ended December 31, 2019 – are replaced with the recognition of an amortization expense of $4.6 million and a financial expense of $2.6 million. The rental charges relating to short-term and low-value In the statement of cash flows, • rent paid on leases that meet the criteria of IFRS 16 are classified within financing activities as principal portion and interest payment on the lease debt, which was $3.4 million for the year ended December 31, 2019; and • short-term lease payments, payments for leases of low-value The table below explains the differences between Operating lease commitments disclosed under IAS 17 as of December 31, 2018, discounted using the incremental borrowing rate at the date of initial application, and Lease liabilities recognized in the statement of financial position at the date of initial application. Operating lease commitments disclosed under IAS 17 as of December 31, 2018 (in thousands): Sale and lease-back agreement $ 31,668 Facility lease agreements $ 28,230 Total $ 59,898 -Discounting impact & assumption changes $ (18,966 ) -Facility lease termination $ (4,220 ) -Other $ 101 Total lease debt $ 36,813 Use of judgment, estimates and assumptions: The application of IFRS 16 “Leases” requires the Group to make assumptions and estimates in order to determine the value of the right-of-use 2.3 Currency of the financial statements The Consolidated Financial Statements are presented in U.S. dollars, which differs from the functional currency of Cellectis, which is the euro. All financial information (unless indicated otherwise) is presented in thousands of U.S. dollars. The statements of financial position of consolidated entities having a functional currency different from the U.S. dollar are translated into U.S. dollars at the closing exchange rate (spot exchange rate at the statement of financial position date) and the statements of operations, statements of comprehensive income (loss) and statements of cash flows of such consolidated entities are translated at the average period to date exchange rate. The resulting translation adjustments are included in equity under the caption “Currency Translation Adjustments” in the Consolidated Statements of Changes in Shareholders’ Equity. 2.4 Basis of consolidation Accounting policy We control all the legal entities included in the consolidation. An investor controls an investee when the investor is exposed to variable returns from its involvement with the investee, and has the ability to affect those returns through its power over the investee. Control requires power, exposure to variability of returns and a linkage between the two. To have power, the investor needs to have existing rights that give it the current ability to direct the relevant activities that significantly affect the investee’s returns. In order to ascertain control, potential voting rights which are substantial are taken into consideration. Consolidation of a subsidiary begins when the Group obtains control over the subsidiary and ceases when the Group loses control of the subsidiary. All intra-group assets and liabilities, equity, income, expenses and cash flows relating to transactions between members of the Group are eliminated in full consolidation. Consolidated entities For the year ended December 31, 2019, the consolidated group of companies (sometimes referred to as the “Group”) includes Cellectis S.A., Cellectis, Inc., Cellectis Biologics Inc., which was incorporated on January 18, 2019, and Calyxt, Inc. As of December 31, 2019, Cellectis S.A. owns 100% of Cellectis, Inc., which owns 100% of Cellectis Biologics, Inc., and approximately 68.9% of Calyxt’s outstanding shares of common stock. As of December 31, 2018, Cellectis S.A. owned 100% of Cellectis, Inc. and approximately 69.5% of Calyxt’s outstanding shares of common stock. Until July 25, 2017, Cellectis S.A. fully owned Calyxt, Inc. On July 25, 2017, Calyxt closed its IPO with $64.4 million in gross proceeds to Calyxt from the sale of 8,050,000 shares at $8 per share, including the full exercise of the underwriter’s over-allotment option and Cellectis’ purchase of $20.0 million of shares in the IPO. On May 22, 2018, Calyxt Inc completed a follow-on follow-on follow-on Non-controlling Non-controlling non-controlling follow-on 2.5 Foreign currency Foreign currency transactions and balances Significant transactions in foreign currencies are translated into the respective functional currencies at the exchange rates effective at the transaction dates, otherwise the average rate of the previous month is used for non-significant The resulting exchange gains or losses are recorded in the consolidated statements of operations in financial gain (loss). Foreign currency translation The assets and liabilities of foreign operations having a functional currency different from the euro are translated into euros at the period end exchange rate. The income and expenses of foreign operations are translated into euros using the average exchange rate for the reporting period. Gains and losses arising from currency translation are recognized in other comprehensive loss. Consolidated financial statements are then converted into dollars using the method described in Note 2.4. The difference in effect of exchange rate changes on cash and cash equivalents between the statements of consolidated operations and consolidated cash flows is mainly explained by the following elements: • the differential between the average exchange rate and the period end rates applied to the cash flows of the period; • the differential between the opening exchange rates and the period end exchanges rate applied on our opening cash and cash equivalents balance denominated in dollars; and • the foreign exchange rate impact of the conversion of the financial statements of our US subsidiaries. 2.6 Use of judgment, estimates and assumptions The preparation of these consolidated financial statements requires management to make judgments, estimates and assumptions that affect the reported amounts of revenues, expenses, assets and liabilities, and the accompanying disclosures, including the disclosure of contingent liabilities. Actual amounts may differ from those estimates. The Group’s exposure to risks and uncertainties is disclosed in Note 8.3: Financial instruments risk management and policies. Estimates and assumptions The key assumptions concerning the future and other key sources of estimation uncertainty at the period end date, that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year, are described below. The Group based its assumptions and estimates on parameters available when the consolidated financial statements were prepared. Existing circumstances and assumptions about future developments, however, may change due to market changes or circumstances arising that are beyond the control of the Group. Such changes are reflected in the assumptions when they occur. • Revenue recognition – Note 3.1 • Share-based payments – Note 16 • Provisions for risks and charges – Note 18 • Right-of-use

Information concerning the Grou

Information concerning the Group's Consolidated Operations	12 Months Ended
	Dec. 31, 2019
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Information concerning the Group's Consolidated Operations	Note 3. Information concerning the Group’s Consolidated Operations 3.1 Revenues and other income Accounting policies Collaboration agreements and licenses Under IFRS 15, “Revenue from contracts with customers”, revenue is recognized when Cellectis satisfies a performance obligation by transferring a distinct good or service (or a distinct bundle of goods and or/ services) to a customer, i.e. when the customer obtains control of these goods or services. We have entered into certain research and development collaboration agreements that consist of the licensing of rights to technology, research and development programs, research and development cost reimbursements and royalties. We have analyzed the agreements to identify the separate performance obligations. These collaboration agreements may generate cash flows through non-refundable non-cancelable, non-refundable co-contracting Up-front Research and development costs reimbursements are recognized on a time and material basis over the length of the specific research and development project. Milestone payments represent variable consideration, the receipt of which is dependent upon the achievement of certain scientific, regulatory, or commercial milestones. Such payments are considered variable consideration. We recognize milestone payments when it is highly probable that any revenue recognized will not be subsequently reversed. This includes consideration of whether the performance obligation is achieved and may be when the triggering event has occurred, depending on the nature of the triggering event, there are no further contingencies or services to be provided with respect to that event, and the co-contracting Royalty revenues arise from our contractual entitlement to receive a percentage of product sales achieved by co-contracting In addition, we license our technology to other third parties and revenues are recognized ratably over the period of the license agreements. Sales of products and services Revenues on sales of products are recognized once the control over the delivered products is transferred to the customer. Sales include shipping and handling charges if billed to the customer and are reported net of trade promotion and other costs, including estimated allowances for returns, unsalable product and prompt pay discounts. Sales, use, value-added and other excise taxes are not recognized in revenue. Trade promotions are recorded based on estimated participation and performance levels for offered programs at the time of sale. We generally do not allow a right of return. We also offer research services, which revenue is recognized over time, as the customer receives the benefits of the services. Research Tax Credit The main Research Tax Credit from which we benefit is the Crédit d’Impôt Recherche, We apply for CIR for research expenditures incurred in each fiscal year and recognize the amount claimed in the line item “Other income” in the same fiscal year. Research tax credit is subject to audit of tax authorities. When tax authorities’ payment related to CIR is late, default interests are applied and are recognized in “other income”. Details of revenues and other income Revenues by country of origin and other income For 2017 2018 2019 $ in thousands From France 24,680 12,495 7,896 From USA 508 236 7,294 Revenues 25,188 12,731 15,190 Research tax credit 8,327 8,561 7,800 Subsidies and other 201 140 — Other income 8,528 8,701 7,800 Total revenues and other income 33,715 21,432 22,990 For the years ended December 31, 2019, 2018 and 2017, the revenue from France was generated by Cellectis S.A. For the years ended December 31, 2019, 2018 and 2017, the revenue from USA was generated by Calyxt, Inc. Revenues by nature For 2017 2018 2019 $ in thousands Recognition of previously deferred upfront payments 14,875 7,114 — Other revenues 7,945 3,383 6,055 Collaboration agreements 22,821 10,497 6,055 Licenses 2,270 2,142 1,762 Products & services 97 92 7,373 Total revenues 25,188 12,731 15,190 Revenues are primarily generated by therapeutics activities, which are mainly attributable to our entering into two major collaboration agreements signed with Pfizer Inc. and Les Laboratoires Servier during 2014. Effective as of April 2018, Pfizer sold certain assets to which the Research Collaboration and License Agreement relates to Allogene Therapeutics, Inc. (“Allogene”) (the “Asset Contribution Agreement”). As part of this Asset Contribution Agreement, Pfizer assigned the Research Collaboration and License Agreement to Allogene , and on March 7, 2019, we and Allogene agreed to terminate the Research Collaboration and License Agreement and entered into a new license agreement (the “Allogene License Agreement”) to reflect the relationship between us and Allogene following the asset contribution. In 2017 and 2018, revenue previously deferred was recognized upon satisfaction of performance obligations . In 2017 and 2018, other revenues primarily consisted of research and development cost reimbursement. In addition to the cost reimbursement, for the year ended December 31, 2019, other revenues also include the recognition of a $5.0 million milestone which is associated with the initiation of the study of ALLO-715 in 2019. For the years ended December 31, 2019, 2018 and 2017 revenues related to licenses includes royalties received under our various license agreements. For the year ended December 31, 2019, products and services revenues mainly include the revenues of plants activities which in 2019 are primarily attributable to the commercialization of ’s high oleic soybean meal for $5.6 million and high oleic soybean oil for $1.7 million. Entity-wide disclosures: In , two clients represent more than % of the total revenue: Client A with % and Client B with %. In , two clients represent more than % of the total revenue: Client A with % and Client B with %. In , two clients represent more than % of the total revenue: Client A with % and Client B with %. 3.2 Operating expenses Accounting policies Prior to 2019, cost of goods sold represented immaterial costs associated with Calyxt’s out-licensing Royalty expenses correspond to costs from license agreements that we entered into to obtain access to technology that we use in our product development efforts. Depending on the contractual provisions, expenses are based either on a percentage of revenue generated by using the patents based on fixed annual royalties or conditioned by milestones. Research and development expenses include employee-related costs, laboratory consumables, materials supplies and facility costs, as well as fees paid to non-employees Selling, general and administrative expenses consist primarily of employee-related expenses for executive, business development, intellectual property, finance, legal and human resource functions. Administrative expenses also include facility-related costs and service fees, other professional services, recruiting fees and expenses associated with maintaining patents. We classify a portion of personnel and other costs related to information technology, human resources, business development, legal, intellectual property and general management in research and development expenses based on the time that each employee or person spent contributing to research and development activities versus sales, general and administrative activities. Details of operating expenses by nature F 2017 2018 2019 $ in thousands Cost of revenue Cost of good sold — — (9,280 ) Royalty expenses (2,620 ) (2,739 ) (2,112 ) Cost of revenue (2,620 ) (2,739 ) (11,392 ) For 2017 2018 2019 $ in thousands Research and development expenses Wages and salaries (12,986 ) (16,452 ) (21,294 ) Social charges on free shares and stock option grants (1,088 ) (99 ) (1,357 ) Non-cash (23,832 ) (18,057 ) (12,260 ) Personnel expenses (37,906 ) (34,608 ) (34,911 ) Purchases and external expenses (38,458 ) (40,458 ) (49,251 ) Other (2,863 ) (1,501 ) (7,880 ) Total research and development expenses (79,227 ) (76,567 ) (92,042 ) For 2017 2018 2019 $ in thousands Selling, general and administrative expenses Wages and salaries (7,019 ) (11,373 ) (12,822 ) Social charges on free shares and stock option grants (881 ) (29 ) (491 ) Non-cash (26,586 ) (19,161 ) (14,621 ) Personnel expenses (34,486 ) (30,563 ) (27,934 ) Purchases and external expenses (9,138 ) (14,251 ) (11,431 ) Other (1,126 ) (2,433 ) (3,652 ) Total selling, general and administrative expenses (44,750 ) (47,248 ) (43,017 ) For 2017 2018 2019 $ in thousands Personnel expenses Wages and salaries (20,005 ) (27,825 ) (34,116 ) Social charges on free shares and stock option grants (1,969 ) (128 ) (1,848 ) Non-cash (50,418 ) (37,218 ) (26,881 ) Total personnel expenses (72,392 ) (65,171 ) (62,845 ) 3.3 Financial income and expenses Accounting policies Financial income and financial expense include, in particular, the following: • Interest income from savings accounts and fixed term bank deposits; • Interest expense from leases; • Foreign exchange gain (loss) from transactions in foreign currencies; and • Other financial income and expenses, mainly derived from fair value adjustments related to our financial assets and derivative instruments. Details of financial income and expenses For 2017 2018 2019 Interest income 1,974 6,787 6,985 Foreign exchange gain 1,185 13,597 4,481 Other financial revenues 4,102 188 505 Total financial revenues 7,262 20,572 11,971 Interest expenses — (39 ) (3 ) Interest expenses for lease s (4 ) (7 ) (2,603 ) Foreign exchange loss (17,734 ) (3,090 ) (671 ) Other financial expenses (556 ) (677 ) (354 ) Total financial expenses (18,294 ) (3,813 ) (3,631 ) Total (11,032 ) 16,758 8,340 The de decrease and expenses related to IFRS 16 application , increase and the increase in ne t int eres t income ( $0.2 million and other immate r variances for $0.1 mill i The increase in financial income and expenses between 2017 and 2018 of $27.8 million was mainly attributable to the increase in net foreign exchange gain ($27.0 million), the increase in interest income ($4.8 million) partly offset by the decrease of foreign exchange derivatives fair value adjustment ($4.0 million), included in other financial revenues and expenses. 3.4 Income tax Accounting policies Income tax (expense or income) comprises current tax expense (income) and deferred tax expense (income). Deferred taxes are recognized for all the temporary differences arising from the difference between the tax basis and the accounting basis of assets and liabilities. Tax losses that can be carried forward or backward may also be recognized as deferred tax assets. Tax rates that have been enacted as of the closing date are utilized to determine deferred tax. Deferred tax assets are recognized only to the extent that it is likely that future profits will be sufficient to recover them. We have not recorded deferred tax assets or liabilities in the statements of financial position. Tax proof For the year ended December 31, 2017 2018 2019 $ in thousands Income (loss) before taxes from continuing operations (103,683 ) (88,333 ) (115,212 ) Theoretical group tax rate 34.43 % 23.66 % 25.35 % Theoretical tax benefit (expense) 35,698 20,901 29,208 Increase/decrease in tax benefit arising from: Permanent differences 293 832 (1,131 ) Research tax credit 2,926 2,079 2,786 Share-based compensation & other IFRS adjustments (8,297 ) (8,065 ) (7,828 ) Non recognition of deferred tax assets related to tax losses and temporary differences (30,713 ) (15,652 ) (23,079 ) Other differences 92 (95 ) 43 Effective tax expense — — — Effective tax rate 0.00 % 0.00 % 0.00 % Deferred tax assets and liabilities As of December 31, 2017 2018 2019 $ in thousands Credits and net operating loss carryforwards 51,640 65,555 102,112 Pension commitments 548 569 714 Leases (12 ) (4 ) 47 Impairment of assets 10 10 1 Revenue recognition — 200 197 Other 604 491 284 Total unrecognized deferred tax assets, net (52,790 ) (66,823 ) (103,354 ) We have cumulative tax loss carryforwards for the French entity of the Group totaling $246 million as of December 31, 2019, $186 million as of December 31, 2018 and $144 million as of December 31, 2017. Such carryforwards can be offset against future taxable profit within a limit of $1.0 million per year, plus 50% of the profit exceeding this limit. Remaining unused losses will continue to be carried forward indefinitely. The cumulative tax loss carryforwards for the U.S. entities of the Group totaled $162 million as of December 31, 2019, $86 million as of December 31, 2018 and $62 million as of December 31, 2017. Calyxt’s carryforward periods are as follows: $64.0 million do not expire; zero expire in 2019 and 2020; and $41.9 million expire in 2032 and beyond. 3.5 Reportable segments Accounting policies Reportable segments are identified as components of the Group that have discrete financial information available for evaluation by the Chief Operating Decision Maker (“CODM”), for purposes of performance assessment and resource allocation. Cellectis’ CODM is composed of: • The Chairman and Chief Executive Officer; • The Chief Operating Officer (through July 24, 2019); • The Executive Vice President Technical Operation (beginning July 22, 2019); • The Executive Vice President Strategic Initiatives; • The Executive Vice President Global Quality (beginning July 22, 2019); • The Chief Scientific Officer; • The Chief Financial Officer; • The General Counsel; • The VP Corporate Development (beginning November, 2019); and • The Chief Regulatory & Compliance Officer. We view our operations and manage our business in two operating and reportable segments that are engaged in the following activities: • Therapeutics: • Plants: There are inter-segment transactions between the two reportable segments, including allocation of corporate general and administrative expenses by Cellectis S.A. and allocation of research and development expenses to the reportable segments. With respect to corporate general and administrative expenses, Cellectis S.A. has provided Calyxt, Inc. with general sales and administrative functions, accounting and finance functions, investor relations, intellectual property, legal advice, human resources, communication and information technology under a Management Services Agreement. As of December 31, 2019, Calyxt has internalized nearly all of the services previously provided by Cellectis under this agreement. Under the Management Services Agreement, Cellectis S.A. charges Calyxt, Inc. in euros at cost plus a mark-up 12-month The intersegment revenues represent the transactions between segments. Intra-segment transactions are eliminated within a segment’s results and intersegment transactions are eliminated in consolidation as well as in key performance indicators by reportable segment. Information related to each reportable segment is set out below. Segment revenues and other income, Research and development expenses, Selling, general and administrative expenses, and Cost of revenue and other operating income and expenses, and Adjusted net income (loss) attributable to shareholders of Cellectis (which does not include non-cash Adjusted Net Income (Loss) attributable to shareholders of Cellectis S.A. is not a measure calculated in accordance with IFRS. Because Adjusted Net Income (Loss) attributable to shareholders of Cellectis excludes Non-cash non-cash The net income (loss) includes the impact of the operations between segments while the intra-segment operations are eliminated. Details of key performance indicators by reportable segment $ in thousands For the year ended December 31, 2017 For the year ended December 31, 2018 For the year ended December 31, 2019 Plants Therapeutics Total Plants Therapeutics Total Plants Therapeutics Total External revenues 508 24,680 25,188 236 12,495 12,731 7,294 7,896 15,190 External other income 239 8,290 8,528 178 8,523 8,701 — 7,800 7,800 External revenues and other income 747 32,969 33,715 414 21,018 21,432 7,294 15,696 22,990 Cost of revenue (390 ) (2,230 ) (2,620 ) (595 ) (2,144 ) (2,739 ) (9,275 ) (2,117 ) (11,392 ) Research and development expenses (6,057 ) (73,170 ) (79,227 ) (8,638 ) (67,929 ) (76,567 ) (12,390 ) (79,652 ) (92,042 ) Selling, general and administrative expenses (13,143 ) (31,607 ) (44,750 ) (21,067 ) (26,180 ) (47,248 ) (26,090 ) (16,927 ) (43,017 ) Other operating income and expenses 6 225 232 (50 ) 81 31 25 (116 ) (91 ) Total operating expenses (19,584 ) (106,782 ) (126,366 ) (30,351 ) (96,172 ) (126,523 ) (47,730 ) (98,812 ) (146,542 ) Operating income (loss) before tax (18,837 ) (73,813 ) (92,650 ) (29,937 ) (75,154 ) (105,091 ) (40,436 ) (83,116 ) (123,552 ) Financial gain (loss) — (11,032 ) (11,032 ) 1,420 15,339 16,758 294 8,045 8,340 Net income (loss) (18,837 ) (84,846 ) (103,683 ) (28,517 ) (59,816 ) (88,333 ) (40,142 ) (75,071 ) (115,212 ) Non controlling interests 4,315 — 4,315 9,640 — 9,640 13,121 — 13,121 Net income (loss) attributable to shareholders of Cellectis (14,522 ) (84,846 ) (99,368 ) (18,877 ) (59,816 ) (78,693 ) (27,021 ) (75,071 ) (102,091 ) R&D non-cash 967 22,623 23,590 838 16,852 17,689 1,619 10,010 11,629 SG&A non-cash 4,990 20,345 25,335 5,218 11,655 16,873 6,673 4,940 11,613 Adjustment of share-based compensation attributable to shareholders of Cellectis 5,957 42,968 48,925 6,056 28,507 34,563 8,292 14,950 23,242 Adjusted net income (loss) attributable to shareholders of Cellectis (8,565 ) (41,877 ) (50,442 ) (12,821 ) (31,309 ) (44,130 ) (18,729 ) (60,121 ) (78,849 ) Depreciation and amortization (551 ) (2,820 ) (3,371 ) (637 ) (1,740 ) (2,377 ) (1,233 ) (5,642 ) (6,875 ) Additions to tangible and intangible assets 792 1,849 2,642 1,871 3,040 4,911 2,998 14,668 17,666 Impairment of tangible assets — (798 ) (798 ) — — — — — —

Impairment tests

Impairment tests	12 Months Ended
	Dec. 31, 2019
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Impairment tests	Note 4. Impairment tests Accounting policy Amortizable intangible assets, depreciable tangible assets and right-of-use Our cash-generating units (“CGUs”) correspond to the operating/reportable segments: Therapeutics and Plants. Results of impairment test No 2018 or 2019. In 2017, as we had the willingness to discontinue the lease of the facility in Montvale, New Jersey (USA), we recorded a $0.8 million tangible assets impairment.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2019
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Intangible assets	Note 5. Intangible assets Accounting policy Capitalization of development expenses In accordance with IAS 38 Intangible Assets • technical feasibility necessary for the completion of the development project; • intention on our part to complete the project and to utilize it; • capacity to utilize the intangible asset; • proof of the probability of future economic benefits associated with the asset; • availability of the technical, financial, and other resources for completing the project; and • reliable evaluation of the development expenses. Other intangible assets The other intangible assets we acquired with definite useful lives are recognized at cost less accumulated amortization and impairment. Amortization expense is recorded on a straight-line basis over the estimated useful lives of the intangible assets, in the line Research and Development expenses or Selling, general and administrative expenses of the Statement of Consolidated Operations, depending on the use of the related asset. The estimated useful lives are as follows: • Software: from 1 3 • Patents: amortized from acquisition until legal protection expires, maximum of 20 Details of intangible assets $ in thousands Software and Patents Assets under construction Total Net book value as of January 1, 2017 924 419 1,343 Change in scope — — — Additions to intangible assets 6 135 141 Depreciation expense (231 ) — (231 ) Translation adjustments 112 66 178 Net book value as of December 31, 2017 811 619 1,431 Gross value at end of period 2,571 517 3,190 Accumulated depreciation and impairment at end of period (1,759 ) — (1,759 ) Net book value as of January 1, 2018 811 619 1,431 Change in scope — — — Additions to intangible assets 14 103 117 Disposal of intangible assets (7 ) — (7 ) Reclassification 6 — 6 Depreciation expense (217 ) — (217 ) Translation adjustments (30 ) (31 ) (61 ) Net book value as of December 31, 2018 577 691 1,268 Gross value at end of period 2,454 691 3,146 Accumulated depreciation and impairment at end of period (1,878 ) — (1,878 ) Net book value as of January 1, 2019 577 691 1,268 Change in scope — — — Additions to intangible assets 84 (2 ) 82 Disposal of intangible assets (50 ) — (50 ) Reclassification 6 — 6 Depreciation expense (174 ) — (174 ) Translation adjustments (12 ) (12 ) (24 ) Net book value as of December 31, 2019 431 677 1,108 Gross value at end of period 2,448 677 3,125 Accumulated depreciation and impairment at end of period (2,017 ) — (2,017 ) Intangible assets mainly consist of electroporation technology patents acquired in 2011. The 2017, 2018 and 2019 additions in intangible assets under construction corresponds to the internal development of existing technology.

Right-of-use assets

Right-of-use assets	12 Months Ended
	Dec. 31, 2019
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Right-of-use assets	Note 6 Right-of-use Accounting policy Lease contracts recognition Lease contracts, as defined by IFRS 16 “Leases”, are recorded in the statement of consolidated financial position, which leads to the recognition of: • an asset representing a right of use of the asset leased during the lease term of the contract “right-of-use”; • a liability related to the payment obligation “lease debt”. Measurement of the right-of At the commencement date, the right-of-use • the amount of the initial measurement of the lease liability, to which is added, if applicable, any lease payments made at or before the commencement date, less any lease incentives received; • where relevant, any initial direct costs incurred by the lessee for the conclusion of the contract. These are incremental costs which would not have been incurred if the contract had not been concluded; and • estimated costs for restoration of the leased asset according to the terms of the contract. Following the initial recognition, the right-of-use Measurement of the lease liability At the commencement date, the lease liability is recognized for an amount equal to the present value of the lease payments over the lease term. Amounts involved in the measurement of the lease liability are: • fixed payments (including in-substance in-substance • variable lease payments that depend on an index or a rate, initially measured using the index or the rate in force at the lease commencement date; amounts expected to be payable by the lessee under residual value guarantees; and • payments of penalties for terminating the lease, if the lease term reflects the lessee exercising an option to terminate the lease. The lease liability is subsequently measured based on a process similar to the amortized cost method using the discount rate: • the liability is increased by the accrued interests resulting from the discounting of the lease liability, at the beginning of the lease period; and • payments made are deducted. The interest cost for the period as well as variable payments, not taken into account in the initial measurement of the lease liability and incurred over the relevant period are recognized as costs. In addition, the lease liability may be remeasured in the following situations: • the occurrence of a change in the lease term or a modification related to the assessment of the reasonably certain nature (or not) of the exercise of an option, • a remeasurement linked to residual value guarantees, • the occurrence of an adjustment to the rates and indices according to which the rents are calculated when rent adjustments occur. Main contracts applicable Based on its analysis, the Group has identified lease contracts according to the standard concerning office buildings, laboratories, production facilities and storage facilities. For purposes of IFRS 16, the lease term reflects the Group’s reasonable expectation of the period during which the underlying asset will be used. The discount rate used to calculate the lease debt is determined, for each portfolio of assets, according to the incremental borrowing rate at the contract date. The incremental borrowing rate is the rate of interest that a lessee would have to pay to borrow over a similar term, and with a similar security, the funds necessary to obtain an asset of a similar value to the right-of-use The rental charges relating to short terms and low value lease remains classified as leases expenses in operating expenses. Details of Right-of-use IFRS 16 “Leases” is applicable for annual periods beginning on or after January 1, 2019. The consequence of the application of this standard is to recognize a right of use and lease liability on the balance sheet. For the leaseback on Calyxt Headquarters, according to IFRS 16, the value of the right-of-use The breakdown of right-of-use Building lease Office and Total $ in thousands Net book value as of January 1, 2019 as restated 36,061 1,508 37,569 Additions 11,357 1,516 12,873 Depreciation expense (4,058 ) (520 ) (4,578 ) Translation adjustments (248 ) (4 ) (252 ) Net book value as of December 31, 2019 43,112 2,500 45,612 Gross value at end of period 47,175 3,153 50,328 Accumulated depreciation at end of period (4,063 ) (653 ) (4,716 )

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2019
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Property, plant and equipment	Note 7 Accounting policy Property, plant and equipment are recognized at acquisition cost less accumulated depreciation and any impairment losses. Acquisition costs include expenditures that are directly attributable to the acquisition of the asset and costs to ready it for use. Depreciation is expensed on a straight-line basis over the estimated useful lives of the assets. If components of property, plant and equipment have different useful lives, they are accounted for separately. The estimated useful lives are as follows: • Buildings and other outside improvements 10-20 • Leasehold improvements 5-10 • Office furniture 10 years • Laboratory equipment 3-10 • Office equipment 5 years • IT equipment 3 years Depreciation methods, useful lives and residual values are reviewed at each reporting date and adjusted, if appropriate. Any gain or loss on disposal of an item of property, plants and equipment is determined by comparing the proceeds from disposal with the carrying amount of the item. The net amount is recognized in the statement of consolidated operations under the line item “Other operating income and expenses.” Before IFRS 16 adoption as of January 1, 2019, payments made under operating leases were expensed on a straight-line basis over the term of the lease. Lease incentives received were recognized as an integral part of the total lease expense, over the term of the lease. If, according to the terms of a lease, it appeared that substantially all the risks and rewards incidental to ownership were transferred from the lessor to the lessee, the associated leased assets were initially recognized as an asset at the lower of their fair value and the present value of the minimum lease payments and subsequently depreciated or impaired, as necessary. The associated financial obligations were reported in the line item “non-current Details of property, plant and equipment Lands and Technical Fixtures, Assets under Total $ in thousands Net book value as of January 1, 2017 12,436 2,858 707 898 16,900 Additions to tangible assets 718 701 203 878 2,501 Disposal of tangible assets (9,243 ) (103 ) 2 (109 ) (9,453 ) Reclassification 14 47 18 (79 ) — Depreciation expense (972 ) (1,126 ) (245 ) (798 ) (3,140 ) Translation adjustments 206 127 68 18 418 Net book value as of December 31, 2017 3,159 2,505 753 809 7,226 Gross value at end of period 6,936 12,114 1,447 1,606 22,103 Accumulated depreciation and impairment at end of period (3,777 ) (9,609 ) (693 ) (798 ) (14,877 ) Net book value as of January 1, 2018 3,159 2,505 753 809 7,226 Additions to tangible assets 879 1,622 1,820 1,942 6,263 Disposal of tangible assets — (49 ) (690 ) (426 ) (1,164 ) Reclassification 39 216 793 (1,053 ) (6 ) Depreciation expense (758 ) (854 ) (478 ) — (2,091 ) Translation adjustments (90 ) (46 ) (27 ) (25 ) (188 ) Net book value as of December 31, 2018 3,229 3,393 2,172 1,247 10,041 Gross value at end of period 7,604 13,297 3,215 2,045 26,160 Accumulated depreciation and impairment at end of period (4,375 ) (9,903 ) (1,043 ) (798 ) (16,119 ) Net book value as of January 1, 2019 as restated* 3,229 2,084 2,172 1,247 8,732 Additions to tangible assets 318 374 329 16,563 17,584 Disposal of tangible assets — (10 ) (1 ) (419 ) (430 ) Reclassification 15 1,974 630 (2,624 ) (5 ) Depreciation expense (192 ) (1,247 ) (684 ) — (2,123 ) Translation adjustments (40 ) (15 ) (11 ) 20 (46 ) Net book value as of December 31, 2019 3,330 3,160 2,435 14,787 23,712 Gross value at end of period 7,833 13,962 4,149 15,585 41,529 Accumulated depreciation and impairment at end of period (4,503 ) (10,802 ) (1,714 ) (798 ) (17,817 ) * See note 2.2 on IFRS16 application No In 2017, Calyxt entered into a transaction whereby it sold a certain land and building (with a total net book value of $ 9.2 The sale and lease-back agreement has a defined lease term and was classified as an operating lease agreement under IAS 17. According to IFRS 16, this lease receives the standard accounting treatment for operating leases existing at the date of initial application and the value of the right-of-use asset is adjusted for the amount of the net deferred losses recognized in the statement of financial position immediately before the date of initial application, which was $1.8 million. For the year ended December 31, 2019, we continued our investments in research and development equipment in both the United States of America and France. The addition in tangible assets reflects improvements of Calyxt and Cellectis sites for $ 0.3 0.7 Assets under construction as of December 31, 2019 primarily relates to Cellectis’ new raw materials manufacturing facility in Paris ($ 4.9 8.8

Financial assets and liabilitie

Financial assets and liabilities	12 Months Ended
	Dec. 31, 2019
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Financial assets and liabilities	Note 8 8 The new standard IFRS 9 “Financial instruments” is of mandatory application since January 1, 2018. Cellectis elected not to restate the 2016 and 2017 comparative periods, as authorized by the standard. Such adoption did not lead to any adjustment recorded in the Group opening equity at January 1, 2018. IFRS 9 comprises three phases: classification and measurement of financial assets and liabilities, impairment of financial assets and hedge accounting. Cellectis was not affected by the new classification required by the standard to determine the way financial assets are recognized and measured. Financial assets Under IFRS 9, Cellectis holds either: • financial assets measured at amortized cost or; • financial assets measured at fair value through profit or loss. Non-current Current financial assets correspond to investments and are recorded at fair value through profit and loss, which is the nominal value of the investment adjusted with the daily mark-to-market Trade and other receivables are recorded at fair value, which is the nominal value of invoices unless payment terms require a material adjustment for the time value discounting effect at market interest rates. Trade receivables are subsequently measured at amortized cost. A provision for expected credit losses for trade and other receivables is recognized if their recoverable amount is less than their carrying amount. The introduction of a new expected loss model for impairment of financial assets under IFRS 9 had no significant impact on the initial recognition of Cellectis trade and other receivables. Receivables are classified as current assets, except for those with a maturity exceeding 12 months after the reporting date. Government grants to Cellectis related to research and development expenses for research programs are recognized as subsidies receivables in the period in which the expenses subject to the subsidy have been incurred, provided there is a reasonable assurance that we will comply with conditions attached to the subsidy and that the subsidy will be received. Financial liabilities The application of IFRS 9 has no impact on the Cellectis’ accounting policy regarding financial liabilities. Financial liabilities include trade and other payables, finance leases and conditional advances. We initially recognize financial liabilities on the transaction date, which is the date that we become a party to the contractual provisions of the instrument. We derecognize financial liabilities when our contractual obligations are discharged, canceled or expire. Financial liabilities are valued at amortized cost. The amount of interest recognized in financial expenses is calculated by applying the financial liability’s effective interest rate to its carrying amount. Any difference between the expense calculated using the effective interest rate and the actual interest payment impacts the value at which the financial liability is recognized. Liabilities for short term employee benefits are included in financial liabilities. They are recognized for the amount expected to be paid under short-term cash bonus or profit-sharing plans if we have a present legal or constructive obligation to pay the amount as a result of past service provided by the employee, and the obligation can be estimated reliably. 8 The following table shows the carrying amounts and fair values of financial assets and financial liabilities. Accounting category Book value on the Fair Value 2018 Fair value through Amortized cost $ in thousands Financial assets Non-current — 1,891 1,891 1,891 Trade receivables — 2,971 2,971 2,971 Subsidies receivables — 17,173 17,173 17,173 Current financial assets 7 381 388 388 Cash and cash equivalents 451,501 — 451,501 451,501 Total financial assets 451,508 22,416 473,924 473,924 Financial liabilities Non-current — 1,018 1,018 1,018 Current financial liabilities — 333 333 333 Trade payables — 15,883 15,883 15,883 Other current liabilities — 8,369 8,369 8,369 Total financial liabilities — 25,603 25,603 25,603 Accounting category Book value on the Fair Value 2019 Fair value through Amortized cost $ in thousands Financial assets Non-current — 5,517 5,517 5,517 Trade receivables — 2,959 2,959 2,959 Subsidies receivables — 9,140 9,140 9,140 Current financial assets — 20,385 20,385 20,385 Cash and cash equivalents 340,522 — 340,522 340,522 Total financial assets 340,522 38,001 378,523 378,523 Financial liabilities Non-current — 46,540 46,540 46,540 Current financial liabilities — 1,067 1,067 1,067 Trade payables — 29,264 29,264 29,264 Other current liabilities — 8,497 8,497 8,497 Total financial liabilities — 85,368 85,368 85,368 8 We have exposure to the following risks arising from financial instruments: Foreign exchange risk A portion of our revenue is generated in currencies other than euro. Although our strategy is to favor the euro as our transaction currency when signing contracts, some agreements have been signed in US dollars (primarily our agreement with Allogene Therapeutics, Inc.). As of December 31, 2018, 66% of our cash and cash equivalents were denominated in US dollars. As of December 31, 2019, 63% of our cash and cash equivalents were denominated in US dollars. Cellectis hedging policy is not affected by the application of IFRS 9 . As of December 31, 2018 and 2019, we did not hold derivative financial instruments to hedge foreign currency exchange risks. Liquidity risk Our financial debt consists of lease debt s for We have incurred losses and cumulative negative cash flows from operations since our inception in 2000, and we anticipate that we will continue to incur losses for at least the next several years. As of December 31, 2019, we held $340.5 million in cash and cash equivalents. Interest rate risk We seek to engage in prudent management of our cash and cash equivalents, mainly cash on hand and common financial instruments (typically short- and mid-term Credit risk Credit risk is the risk of our financial loss if a customer or counterparty to a financial instrument defaults on its contract commitments. We are exposed to credit risk due to our trade receivables, subsidies receivables and cash equivalents. Our policy is to manage our risk by dealing with third parties with good credit standards.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
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Inventories	Note 9. Inventories Accounting policy Inventories are measured at the lower of cost and net realizable value. Cost is determined using the first in first out cost method. They include all costs of seed production and grain Calyxt purchases as well as costs to store, transport and process the grain into finished products. Consideration Calyxt receives from growers when they purchase seed is recorded as a reduction of inventory. Calyxt evaluates inventory balances for obsolescence on a regular basis using projected selling prices for our products, market prices for the underlying agricultural markets, the age of products and other factors that take into consideration our limited operating history. Prior to the commercialization of Caly x t's Description of inventories As of December 31, 2019, inventories amounted to $2.9 million, $2.6 million of which related to Calyxt’s grain and seed costs, and $0.3 million to raw materials and laboratory consumables (representing pharmaceutical and chemical products). As of December 31, 2018, inventories consisted of $0.3 million of raw materials and laboratory consumables (representing pharmaceutical and chemical products). No provision for impairment has been recorded as of December 31, 2019 and 2018.

Trade receivables and other cur

Trade receivables and other current assets	12 Months Ended
	Dec. 31, 2019
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Trade receivables and other current assets	Note 10 Accounting policies for trade receivables and other current assets are described in Note 8 10 As of December 31, As of December 31, 2018 2019 $ in thousands Trade receivables 3,353 3,513 Valuation allowance (382 ) (554 ) Total net value of trade receivables 2,971 2,959 All trade receivables have payment terms of less than one year. The trade receivables are mainly due to collaboration contracts and to the commercialization of Calyxt’s high oleic soybean 10 As of December 31, As of December 31, 2018 2019 $ in thousands Research tax credit 16,842 9,140 Other subsidies 1,598 — Valuation allowance for other subsidies (1,266 ) — Total subsidies receivables 17,173 9,140 Research tax credit receivables as of December 31, 2019 mainly include the accrual for a French research tax credit related to 2019 for $7.9 million. The remaining amount mainly relates to refundable tax credits in the United States. In December 2018, the French Tax Authority initiated an audit related to the 2014, 2015, 2016 and 2017 French research tax credits. Based on our current evaluation of the status of the audit, we do not believe that a provision should be recorded as of December 31, 2019. During the last quarter of 2019, we received payments of $7.4 million and $7.3 million related to 2017 and 2018 tax credit receivables. The valuation allowance for other subsidies was fully reversed in 2019 as a loss was incurred. Research tax credit receivables as of December 31, 2018 include the accrual for a French research tax credit related to 2017 for $8.0 million and to 2018 for $7.8 million and the remaining amount mainly relates to refundable tax credits in the United States. The valuation allowance for other subsidies corresponds mainly to a grant, which was fully reserved in 2014. 10 As of December 31, As of December 31, 2018 2019 $ in thousands VAT receivables 1,679 3,044 Prepaid expenses and other prepayments 10,985 11,829 Tax and social receivables 244 150 Deferred expenses and other current assets 2,425 594 Total other current assets 15,333 15,617 Prepaid expenses and other prepayments primarily include advances to our sub-contractors During the years ended December 31, 2019, and December 31, 2018, we prepaid certain manufacturing costs related to our product candidates UCART123, UCARTCS1 and UCART22 of which the delivery of products or services is expected in the coming months. As of December 31, 2018, deferred expenses and other current assets include (i) a deferred expense of $2.1 million related to the sale and lease-back transaction entered into by Calyxt and (ii) other current assets for $0.3 million. As of January 1, 2019, the $2.1 million deferred expense mentioned above has been reclassified in “Right-of-use mainly relates to As of December 31, 2018, tax and social receivables include $0.2 million of social charges on personnel expenses. As of December 31, 2019, tax and social receivables relate mainly to social charges on personnel expenses and t ax reimburse ment

Current financial assets and Ca

Current financial assets and Cash and cash equivalents	12 Months Ended
	Dec. 31, 2019
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Current financial assets and Cash and cash equivalents	Note 1 1 As of December 31, 2018 Carrying amount Unrealized Gains/(Losses) Estimated fair value $ in thousands Current financial assets 388 — 388 Cash and cash equivalents 451,501 — 451,501 Current financial assets and cash and cash equivalents 451,889 — 451,889 As of December 31, 2019 Carrying amount Unrealized Gains/(Losses) Estimated fair value $ in thousands Current financial assets 20,385 — 20,385 Cash and cash equivalents 340,522 — 340,522 Current financial assets and cash and cash equivalents 360,907 — 360,907 1 1 Accounting policies Current financial assets include current restricted cash and other current financial assets. As of December 31, 2019, restricted cash consists of: i. deposit to secure commitment to supplier regarding the manufacturing facility construction for $ 20 ii. deposits to secure a Calyxt furniture and equipment sale-leaseback for $ 1.5 0.4 As of December 31, 2018, restricted cash consists of deposits to secure a Calyxt furniture and equipment sale-leaseback for $1.5 million of which $0.4 million are classified as short-term restricted cash. Financial assets are measured at fair value through profit or loss in accordance with IAS 39 include the following: • Financial assets including embedded derivatives for which Cellectis elected to designate at fair value through profit or loss; • Financial assets managed on a fair value basis; and • Derivative instruments that are not documented in hedging relationships. IFRS 13 (Fair Value Measurement) requires counterparty and own credit risk to be taken into account when measuring the fair value of financial instruments. This risk is estimated on the basis of observable, publicly-available statistical data. 1 1 Accounting policy Cash and cash equivalents are held for the purpose of meeting short-term cash commitments rather than for the purpose of investment or for other purposes. They are readily convertible into a known amount of cash and are subject to an insignificant risk of changes in value. Cash and cash equivalents include cash, bank accounts, money market funds and fixed bank deposits that meet the definition of a cash equivalent. Cash equivalents are fair valued at the end of each reporting period. Details of cash and cash equivalents As of December 31, As of December 31, 2018 2019 $ in thousands Cash and bank accounts 398,178 270,630 Money market funds 13,248 13,722 Fixed bank deposits 40,075 56,170 Total cash and cash equivalents 451,501 340,522 Money market funds earn interest and are refundable overnight. Fixed bank deposits have fixed terms that are less than three months or are readily convertible to a known amount of cash.

Financial liabilities

Financial liabilities	12 Months Ended
	Dec. 31, 2019
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Financial liabilities	Note 1 2 12.1 Detail of financial liabilities As of December 31, As of December 31, 2018 2019 $ in thousands Lease debt s / Finance lease 1,018 46,540 Total non-current 1,018 46,540 Lease debt s / Fina nce lease 333 1,067 Total current financial liabilities 333 1,067 Trade payables 15,883 29,264 Other current liabilities 8,369 8,497 Total Financial liabilities 25,603 85,368 Certain finance leases were recorded under IAS 17. IFRS 16 “Leases” is applicable for annual periods beginning on or after January 1, 2019. The consequence of the application of this standard is to recognize a right-of-use 12.2 Due dates of the financial liabilities Balance as of December 31, 2019 Discounted amount Less than One One to Five More than Five $ in thousands L debts 47,607 1,067 46,540 — Financial liabilities 47,607 1,067 46,540 — Trade payables 29,264 29,264 — — Other current liabilities 8,497 8,497 — Total financial liabilities 85,368 38,828 46,540 —

Other current liabilities

Other current liabilities	12 Months Ended
	Dec. 31, 2019
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Other current liabilities	Note 1 3 As of December 31, As of December 31, 2018 2019 $ in thousands VAT Payables 291 130 Accruals for personnel related expenses 7,041 7,295 Other 1,037 1,072 Total 8,369 8,497 Accruals for personnel are related to annual bonuses, vacations accruals and social expenses on stock options. The increase in accruals for personnel related expenses between December 31, 2018 and December 31, 2019, is mainly driven by higher accrual for annual bonuses due to the increase of headcount recruited both in the United States and in France. As of December 31, 2019 “Other” mainly include payables to fi xed asset suppliers for $0.6 million , other tax As of December 31, 2018 “Other” mainly include Board of Directors attendance fees for $0.3 million liabilities and subsidies liabilities for $0.3 million.

Deferred revenues and contract

Deferred revenues and contract liabilities	12 Months Ended
	Dec. 31, 2019
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Deferred revenues and contract liabilities	Note 14. Deferred revenues and contract liabilities Details of deferred revenues and deferred income As of December 31, 2018 As of December 31, 2019 $ in thousands Deferred revenues and c ontract liab ilities 20,454 20,033 Others 299 — Total Deferred revenue and contract liabilities 20,754 20,033 Deferred revenues The deferred revenues and contract liabilities correspond mainly to upfront payments for the collaboration agreements with Les Laboratoires Servier and Institut de Recherche Servier (together “Servier”). At December 31, 2019, certain development programs were put on hold.

Capital

Capital	12 Months Ended
	Dec. 31, 2019
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Capital	Note 1 5 1 5 Accounting policy In general, each shareholder is entitled to one vote per share at any general shareholders’ meeting. However, our By-Laws Nature of the Transactions Share Capital Share premium Number of shares Nominal value $ in thousands in $ Balance as of January 1, 2017 2,332 568,185 35,335,060 0.05 Capital Increase 26 — 466,950 — Exercise of share warrants, employee warrants and stock options 9 2,921 158,052 — Non-cash — 42,968 — — Other movements — (37 ) — — Balance as of December 31, 2017 2,367 614,037 35,960,062 0.05 Capital Increase 379 178,230 6,146,000 — Exercise of share warrants, employee warrants and stock options 19 7,751 324,007 — Non-cash — 28,507 — — Balance as of December 31, 2018 2,765 828,525 42,430,069 0.05 Capital Increase 2 — 35,600 — Exercise of share warrants, employee warrants and stock options — — — — Non-cash — 14,951 — — Other movements — 2 — Balance as of December 31, 2019 2,767 843,478 42,465,669 0.05 Capital evolution in 2019 • During the full year ended December 31, 2019, 3 3 Capital evolution in 2018 • During the full year ended December 31, 2018, 6,146,000 follow-on 178,611,687 1,939 1,867 322,068 7,525,542 160,000 non-employees 230,629 Capital evolution in 2017 • During the full year ended December 31, 2017, 126,179 121,492 2,173,058 466,950 31,873 31,873 734,234 228,000 non-employees 252,171 BSA 2011: On October 28, 2011, using the delegation of authority granted by the General Assembly held the same day, we issued 12,195,113 warrants (Bon de Souscription d’Actions or “BSA”) to the existing shareholders with a ratio of one BSA for one share. October 28, 2014 was the closing date for the exercise of the “BSA 2011.” Pursuant to the terms of the plan, we issued 1,470,836 ordinary shares for gross proceeds of $16.4 million. Voting rights: After a shareholder continuously holds ordinary shares for two years, each ordinary share held by such shareholder is entitled to two votes. • At December 31, 2019, we had 42,465,669 4,389,581 • At December 31, 2018, we had 42,430,069 5,016,911 • At December 31, 2017, we had 35,960,062 5,155,335 Otherwise, our ordinary shares are not entitled to any preferential voting right or restriction. 1 5 non-employee Share warrants and non-employee Date Type Number of Number of Number of Number of Number of Maximum of shares to be issued Number of Strike price per 07/27/2010 BSPCE E 19,702 — — — 19,702 20,464 19,702 7.97 05/18/2015 Free shares 15,600 — 15,600 — — — — — 03/24/2015 Stock Options 1,730,646 — — 117,652 1,612,994 1,612,994 1,612,994 38.45 03/27/2015 BSA 130,000 — — — 130,000 130,000 130,000 38.45 05/18/2015 BSA 50,000 — — — 50,000 50,000 50,000 29.58 09/08/2015 BSA 224,200 — — — 224,200 224,200 224,200 28.01 09/08/2015 Stock Options 1,770,000 — — 146,800 1,623,200 1,623,200 1,623,200 27.55 03/14/2016 BSA 147,025 — — 147,025 147,025 147,025 27.37 03/14/2016 Stock Options 1,785,271 — — 132,676 1,652,595 1,652,595 1,549,308 22.44 10/28/2016 BSA 148,000 — — 148,000 148,000 148,000 18.68 10/28/2016 Stock Options 2,369,689 — — 190,796 2,178,893 2,178,893 1,634,170 17.90 10/11/2017 BSA 200,000 — — — 200,000 200,000 133,333 24.34 10/11/2017 Stock Options 1,182,500 — — 222,500 960,000 960,000 480,000 22.57 10/08/2018 Free shares 43,000 — 20,000 20,000 3,000 3,000 — — 10/08/2018 Stock Options 100,000 — — 50,000 50,000 50,000 12,500 24.80 12/17/2018 Free shares 13,000 — — — 13,000 13,000 — — 12/17/2018 Stock Options 40,000 — — — 40,000 40,000 10,000 18.37 07/03/2019 Free shares — 3,500 — 1,000 2,500 2,500 — — 07/03/2019 Stock Options — 3,000 — 3,000 — — — 15.69 04/24/2019 Stock Options — 1,562,800 — 93,100 1,469,700 1,469,700 — 18.25 04/24/2019 Free shares — 6,500 — — 6,500 6,500 — — 07/16/2019 Free shares — 9,000 — 5,000 4,000 4,000 — — 11/06/2019 Stock Options — 55,000 — — 55,000 55,000 — 11.06 11/06/2019 Free shares — 21,500 — — 21,500 21,500 — — 11/18/2019 Stock Options — 30,000 — — 30,000 30,000 — 12.33 11/18/2019 Free shares — 16,500 — — 16,500 16,500 — — Total 9,968,633 1,707,800 35,600 982,524 10,658,309 10,659,071 7,774,432 Holders of vested stock options and warrants are entitled to subscribe to a capital increase of Cellectis at predetermined exercise price. • In 2019, our subsidiary Calyxt Inc. granted stock options, restricted stock unit and performance stock unit in Calyxt Inc. representing as of December 31, 2019 a 6.1% interest of that subsidiary if fully exercised to a group of its employees, directors, executive officers and consultants. The compensation expense for 2019 amounted to $4.4 million (see Note 16). • In 2018, our subsidiary Calyxt Inc. granted stock options and restricted stock unit in Calyxt Inc. representing as of December 31, 2018 a 3.1 3.3 6 • In June 2017, our subsidiary Calyxt Inc. granted stock options and restricted stock unit in Calyxt Inc. representing as of December 31, 2017 a 9.8 5.2 6 1 5 Non-controlling On July 25, 2017, Calyxt closed its IPO with $64.4 million in gross proceeds to Calyxt from the sale of 8,050,000 shares at $8 per share, including the full exercise of the underwriter’s over-allotment option and Cellectis’ purchase of $20.0 million of shares in the IPO. On May 22, 2018, Calyxt Inc completed a follow-on follow-on 9 non-controlling The following table summarizes the information relating to each of our subsidiaries that reported non-controlling CALYXT 201 8 201 9 $ in thousands Revenue 236 7,294 Net Profit (Loss) (28,517 ) (40,142 ) Net Profit (Loss) attributable to NCI (9,640 ) (13,121 ) Other comprehensive income (5,373 ) (1,237 ) Total comprehensive income (33,891 ) (41,378 ) Total comprehensive income attributable to NCI (10,330 ) (12,856 ) Current assets 97,735 63,528 Non-current 4,539 22,518 Current liabilities 5,460 6,642 Non-current 8 26 15,121 Net assets 95,987 64,283 Net assets attributable to NCI 29,257 19,973 1 5 In 2008, Cellectis executed a liquidity contract with Natixis Securities (“Natixis”). This contract entitles Natixis to transact on Euronext, on our behalf, in order to enhance the liquidity of transactions and regularity of quotation of our ordinary shares, in an independent way, without hindering the functioning of the market or misleading investors. The initial advance payment made to Natixis for the purpose of making transactions under this contract was $0.4 million. As of December 31, 2017, $0.3 million are classified in treasury shares and the balance is presented in the line item “Other non-current In 2018, we terminated our liquidity contract with Natix is

Share-based payments

Share-based payments	12 Months Ended
	Dec. 31, 2019
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Share-based payments	Note 15. Share-based payments 15.1 Detail of Cellectis equity awards Holders of vested Cellectis stock options and warrants are entitled to exercise such options and warrants to purchase Cellectis Ordinary shares at a fixed exercise price established at the time of such options and warrants are granted during their useful life. For stock options and warrants, we estimate the fair value of each option on the grant date or other measurement date if applicable using a Black-Scholes option-pricing model, which requires us to make predictive assumptions regarding future stock price volatility, employee exercise behavior, dividend yield, and the forfeiture rate. We estimate our future stock price volatility based on Cellectis historical closing share prices over the expected term period. Our expected term represents the period of time that options granted are expected to be outstanding determined using the simplified method. The risk-free interest rate for periods during the expected term of the options is based on the French government securities with maturities similar to the expected term of the options in effect at the time of grant. We have never declared or paid any cash dividends and do not presently plan to pay cash dividends in the foreseeable future. Consequently, we used an expected dividend yield of zero. Options may be priced at 100 percent or more of the fair market value on the date of grant, and generally vest over four years after the date of grant. Options generally expire within ten years after the date of grant. Stock Options The weighted-average fair values of stock options granted and the assumptions used for the Black-Scholes option pricing model were as follows: 2016 2017 2018 Weighted-Average fair values of stock options granted 10.53€ 14.30€ 8.89€ Assumptions: Risk-free interest rate 0.00% - 0.03% 0.03% 0.13% Share entitlement per options 1 1 1 Exercise price 17.90€ - 22.44€ 22.57€ 24.80€ Grant date share fair value 16.42€ - 22.48€ 24.01€ 17.78€ Expected volatility 62.8% - 63.2% 65.6% 63.3% Expected term (in years) 6.11 - 6.12 6.12 6.25 Vesting conditions Service Service Service Vesting period Graded Graded Graded Information on stock option activity follows: Options Weighted- Options Weighted- Remaining Balance as of December 31, 2016 1,355,680 33.75 € 8,436,255 25.43 € 9.09y Granted — — 1,220,000 22.57 € Exercised — — (31,873 ) 20.40 € Forfeited or Expired — — (291,778 ) 22.19 € Balance as of December 31, 2017 3,822,772 28.02 € 9,332,604 25.17 € 8.31y Granted — — 100,000 24.80 € Exercised — — (319,568 ) 19.72 € Forfeited or Expired — — (174,930 ) 23.68 € Balance as of December 31, 2018 5,644,044 27.47 € 8,938,106 25.39 € 7.32y Share-based compensation expense related to stock option awards was $26.0 million in 2018, $36.8 million in 2017, and $45.6 million in 2016. Warrants The weighted-average fair values of warrants granted and the assumptions used for the Black-Scholes option pricing model were as follows: 2016 2017 Weighted-Average fair values of warrants granted 9.33€ 13.20€ Assumptions: Risk-free interest rate 0.00% - 0.04% 0.12% Share entitlement per options 1 1 Exercise price 18.68€ - 27.37€ 24.34€ Grant date share fair value 16.42€ - 22.48€ 24.95€ Expected volatility 62.8% - 63.1% 64.7% Expected term (in years) 6.00 6.00 Vesting conditions Service Service Vesting period Graded Graded Information on warrants activity follows: Warrants Weighted- Warrants Weighted- Remaining Balance as of December 31, 2016 315,928 23.00 € 1,027,261 25.91 € 7.78y Granted — — 240,000 24.34 € Exercised — — (126,179 ) 13.75 € Forfeited or Expired — — (40,113 ) 18.67 € Balance as of December 31, 2017 469,436 28.80 € 1,100,969 27.23 € 8.20y Granted — — 0 0.00 € Exercised — — (1,867 ) 6.16 € Forfeited or Expired — — (180,175 ) 29.95 € Balance as of December 31, 2018 687,252 27.74 € 918,927 26.74 € 7.22y Share-based compensation expense related to warrants awards was $2.3 million in 2018, $3.5 million in 2017, and $4.7 million in 2016. Free shares The free shares granted prior to 2018 are subject to a two-year one-year two-years Information on free shares activity follows: Number of Free Weighted- Unvested balance at December 31, 201 7 15,600 28.17 € Granted 56,000 17.37 € Vested 0 0.00 € Cancelled 0 0.00 € Unvested balance at December 31, 201 8 71,600 27.37 € Granted 57,000 13.04 € Vested (35,600 ) 25.74 € Cancelled (26,000 ) 21.65 € Unvested balance at December 31, 201 9 67,000 13.98 € The fair value of free shares corresponds to the grant date share fair value. We have never declared or paid any cash dividends and do not presently plan to pay cash dividends in the foreseeable future. Consequently, we used an expected dividend yield of zero in determining fair value. Share-based compensation expense related to free shares awards was $0.7 million in 201 9 8 7 1 6 Stock Options The estimated fair values of stock options granted and the assumptions used for the Black-Scholes option pricing model were as follows: 201 7 201 8 201 9 Weighted-Average fair values of stock options granted $4.00 $9.09 $10.21 Assumptions: Risk-free interest rate 1.96% 2.45% - 2.89% 1.7% - 2.5% Share entitlement per options 1 1 1 Exercise price $13.29 $14.24 - $23.39 $4.05 - $15.39 Grant date share fair value $13.29 $14.24 - $23.39 $4.05 - $15.39 Expected volatility 25% 40.86% - 57.22% 52.6% - 78.9% Expected term (in years) 6.6 5.6 - 10.0 6.8 - 10.0 Vesting conditions Service Service Service Vesting period Graded Graded Graded Calyxt estimates the fair value of each option on the grant date or other measurement date if applicable using a Black-Scholes option-pricing model, which requires Calyxt to make predictive assumptions regarding future stock price volatility, employee exercise behavior, dividend yield, and the forfeiture rate. Calyxt estimates its future stock price volatility using the historical volatility of comparable public companies over the expected term of the option. Our expected term represents the period of time that options granted are expected to be outstanding determined using the simplified method. The risk-free interest rate for periods during the expected term of the options is based on the U.S. Treasury zero-coupon Calyxt has not paid and does not expect to pay dividends for the foreseeable future. Options may be priced at 100 percent or more of the fair market value on the date of grant, and generally vest over six ten Information on stock option activity follows: Options Weighted- Options Weighted- Remaining Balance as of December 31, 201 7 1,244,968 $ 5.20 3,883,432 $ 9.16 8.8y Granted 554,243 $ 16.69 Exercised (592,342 ) $ 4.43 Forfeited or Expired (643,446 ) $ 12.52 Balance as of December 31, 201 8 1,278,038 $ 7.45 3,201,887 $ 10.67 8.2y Granted 1,590,000 $ 13.80 Exercised (95,327 ) $ 3.61 Forfeited or Expired (227,696 ) $ 14.68 Other activity 12,495 $ 13.29 Balance as of December 31, 201 9 1,789,567 $ 8.73 4,481,359 $ 11.73 6.8y Stock-based compensation expense related to stock option awards was $6.8 million in 2019, $3.2 million in 2018 and $3.8 million in 2017. The options granted under the plans were originally only exercisable upon a triggering event or initial public offering as defined by the plans. Restricted Stock Units Units settled in stock subject to a restricted period may be granted to key employees under the 2017 Omnibus Plan. Restricted stock units generally vest and become unrestricted over five years after the date of grant. Information on restricted stock unit activity follows: Number of Weighted-Average Unvested balance at December 31, 201 7 1,373,933 $ 13.29 Granted 315,825 $ 16.68 Vested (261,507 ) $ 14.07 Cancelled (376,837 ) $ 13.30 Unvested balance at December 31, 201 8 1,051,414 $ 14.11 Granted 100,000 $ 12.48 Vested (324,043 ) $ 9.69 Cancelled (13,845 ) $ 12.72 Unvested balance at December 31, 201 9 813,526 $ 9.41 The fair value of restricted stock units corresponds to the grant date share fair value. Calyxt has not paid and does not expect to pay dividends for the foreseeable future. Share-based compensation expense related to restricted stock units awards was $4.9 million in 2019, $5.5 million in 2018 and $4.7 million in 2017. Performance Stock Unit In June 2019, Calyxt granted performance stock units, which carry a market condition based on Calyxt share price. These awards contain a continuous service period of three years, the performance period, from the date of grant, followed by a restricted period of two years if the shares are issued following the performance period during which the grantee is required to provide continuous service and the awarded shares must be held by the grantee until the end of the period. The number of shares of common stock delivered following the performance period depends upon the change in Calyxt share price during the performance period. Calyxt granted a targeted 311,667 performance stock units, the performance criteria allow for the actual payout to be between zero and 120 percent of target. The fair value of the performance stock units and the assumptions used for the Monte Carlo simulation were as follows: Date of grant 06/28/2019 Estimated fair values of performance stock units granted $ 7.06 Assumptions: Risk-free interest rate 1.71 % Expected volatility 75.0 % Expected term (in years) 3.0 years Information on performance stock unit activity follows: Number of Weighted- Unvested balance at December 31, 2018 $ — $ — Granted 311,667 $ 7.06 Vested $ — $ — Cancelled $ — $ — Unvested balance at December 31, 2019 311,667 $ 7.06 Share-based compensation expense related to performance stock units awards was $0.2 million in 2019.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2019
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Earnings per share	Note 1 7 Accounting policy Basic earnings per share are calculated by dividing profit attributable to our ordinary shareholders by the weighted average number of ordinary shares outstanding during the period, adjusted to take into account the impact of treasury shares. Diluted earnings per share is calculated by adjusting profit attributable to ordinary shareholders and the weighted average number of ordinary shares outstanding, for the effects of all potentially dilutive ordinary shares (stock-options, free shares, share warrants, employee warrants). Detail of earnings per share For 2017 2018 2019 Net income (loss) attributable to shareholders of Cellectis ($ in thousands) (99,368 ) (78,693 ) (102,091 ) Adjusted weighted average number of outstanding shares, used to calculate both basic and diluted net result per share 35,690,636 40,774,197 42,442,136 Basic / Diluted net income (loss) per share ($ / share) Basic net income (loss) per share ($ /share) (2.78 ) (1.93 ) (2.41 ) Diluted net income (loss) per share ($ /share) (2.78 ) (1.93 ) (2.41 )

Provisions

Provisions	12 Months Ended
	Dec. 31, 2019
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Provisions	Note 1 8 Accounting policy A provision is recognized if, as a result of a past event, we have a present legal or constructive obligation that can be estimated reliably, and it is probable that an outflow of economic benefits will be required to settle the obligation. The amount recognized as a provision is the best estimate of the expenditure required to settle the present obligation at the reporting date. Provisions for retirement and other benefits Our defined benefit obligations, and their cost, are determined using the projected unit credit method. The method consists in measuring the obligation based on a projected end-of-career Actuarial assumptions used to determine the benefit obligations are specific to each country and each benefit plan. The discount rate used is the yield at the reporting date on AA credit-rated bonds with maturity dates that approximate the expected payments for our obligations. Actuarial gains or losses are recognized in the statement of comprehensive loss for the year in which they occur. Other long-term employee benefits Our net obligation for long-term employee benefits other than retirement plans is equal to the value of employees’ future benefits vested in exchange for services rendered in the current and prior periods. The benefits are discounted and the fair value of any plan assets is deducted. The obligation is measured using the projected unit credit method. The discount rate is the same as the one used for the provisions for retirement and other benefits. Actuarial gains or losses are recognized in profit or loss for the year in which they occur. Termination benefits Termination benefits are recognized as a liability and expense at the earlier of the following dates: • When the entity can no longer withdraw the offer of those benefits; and • When the entity recognizes costs for a restructuring that is within the scope of IAS 37 Provisions and involves the payment of termination benefits. Details of provisions 01/01/2018 Additions Amounts used during the period Reversals OCI 12/31/2018 $ in thousands Pension 2,193 314 (54 ) — (175 ) 2,278 Loss on contract 1,876 — (834 ) — 1 1,043 Employee litigation and severance 1 43 — (1 ) (2 ) 41 Commercial litigation 782 646 — (570 ) (8 ) 850 Redundancy plan 7 — — (6 ) (1 ) — Total 4,858 1,003 (888 ) (577 ) (186 ) 4,211 Non-current 3,430 314 (888 ) — (175 ) 2,681 Current provisions 1,427 688 — (577 ) (11 ) 1,528 01/01/2019 Reclassification Additions Amounts used Reversals OCI 12/31/2019 Pension 2,278 — 314 — — 263 2,855 Loss on contract* — 1,043 690 (1,461 ) — — 272 Employee litigation and severance 41 — 715 (43 ) (75 ) 1 639 Commercial litigation 850 — 2,604 (595 ) (17 ) (11 ) 2,832 Total 3,169 1,043 4,323 (2,099 ) (92 ) 253 6,598 Non-current 2,278 314 — — 263 2,855 Current provisions 891 1,043 4,009 (2,099 ) (92 ) (10 ) 3,743 * As of January 1, 2019, Montvale, New Jersey facility lease agreement provision for loss on contract was scoped under IFRS 16 and classified as lease debts. During the period, the agreement has been discontinued which changed its treatment placing it outside the scope of IFRS 16 and resulting in the reclassification to “loss on contract” presented above. During the year ended December 31, 2019, additions mainly relate to (i) the discontinuation of the lease for a non-operational , , (iii) employ ee litigation following a sett lement. During the year ended December 31, 2018, additions mainly relates to (i) operating charges linked with discussions with suppliers for $0.6 million and (ii) pension service cost of the period for $0.3 million (see detail above). Amounts used during the year ended December 31, 2018 mainly consists of (i) the rents payments of the facility lease in Montvale, New Jersey (USA) for $0.8 million and (ii) settlement of commercial litigations with suppliers for $0.6 million. Commitments for compensation payable to employees upon their retirement France In France, pension funds are generally financed by employer and employee contributions and are accounted for as defined contribution plans, with the employer contributions recognized as expense as incurred. There are no actuarial liabilities in connection with these plans. Expenses recorded in the years ended December 31, 2017, 2018 and 2019 amounted to $0.8 million, $1.5 million and $1.1 million, respectively. French law also requires payment of a lump sum retirement indemnity to employees based on years of service and annual compensation at retirement. Benefits do not vest prior to retirement. We are paying this defined benefit plan. It is calculated as the present value of estimated future benefits to be paid, applying the projected unit credit method whereby each period of service is seen as giving rise to an additional unit of benefit entitlement, each unit being measured separately to build up the final. The calculation of legal compensation for termination has changed in 2017 following the publication of a new French law. The two important changes are: • Seniority conditions: the employee must be entitled to an indemnity of 8 working months against one year before. • Calculation of the allowance: 1/4 of a month of salary per year of seniority up to 10 years, against 1/5 before, and no change beyond the 11th year. As part of the estimation of the retirement indemnity to employee, the following assumptions were used for all categories of employees: 2017 2018 2019 % social security contributions 45.00 45.00% 45.00% Salary increases 3.50% 3.50% 3.50% Discount rate 1.75% 1.75% 1.00 % Terms of retirement voluntary retirement Retirement age 65 65 65 The discount rates are based on the market yield at the end of the reporting period on high quality corporate bonds. The following table shows reconciliation from the opening balances to the closing balances for net defined benefit liability and its components. $ in thousands As of January 1, 2017 (562 ) Current service cost (925 ) Interest cost (24 ) Actuarial gains and losses (515 ) Reclassification/CTA (168 ) As of December 31, 2017 (2,194 ) Current service cost (276 ) Interest cost (38 ) Benefit paid 54 Actuarial gains and losses 70 Reclassification/CTA 105 As of December 31, 2018 (2,278 ) Current service cost (275 ) Interest cost (39 ) Benefit paid — Actuarial gains and losses (303 ) Reclassification/CTA 40 As of December 31, 2019 (2,855 ) United States of America There is no defined benefit plan for Cellectis S.A.’s subsidiaries located in the United States.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2019
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Commitments	Note 1 9 Accounting policy The commitment amounts are associated with contracts that are enforceable and legally binding and that specify all significant terms, including fixed or minimum services to be used, fixed, minimum or variable price provisions, and the approximate timing of the actions under the contracts. They do not include obligations under agreements that we can cancel without a significant penalty. Details of commitments As of December 31, 2019 Total Less than 1 1 - 3 years 3 - 5 years More than 5 $ in thousands L s 73,181 4,014 18,886 9,764 40,516 License agreements 18,607 1,389 2,778 2,778 11,662 Manufacturing agreements 6,218 6,218 — — — Clinical & R&D agreements 2,086 1,424 662 — — Con struction agreements 39,741 39,741 — Other agreements 50,896 30,851 20,045 — — Total contractual obligations 190,728 83,637 42,371 12,542 52,179 Obligations under the terms of lease agreement s We have entered into various lease agreements including facility leases agreements for our sites in Paris, France, and in the United-States in New-York City (New-York), Raleigh (North Carolina) and Roseville (Minnesota) for a defined term, as well as finance leases and sales and leaseback for equipment. Obligations under the terms of license agreements We have entered into various license agreements with third parties that subject us to certain fixed license fees, as well as fees based on future events, such as research and sales milestones. We also have collaboration agreements whereby we are obligated to pay royalties and milestones based on future events that are uncertain and therefore they are not included in the table above. Obligations under the terms of manufacturing agreements We have manufacturing agreements whereby we are obligated to pay for services rendered in the next year regarding our products UCART123, UCARTCS1 and UCART22. Obligations under the terms of Clinical & Research agreements We have entered into clinical and research agreements where we are obligated to pay for services to be provided in the next years regarding our research collaboration agreements , s Obligations under the terms of Construction agreements We have entered into a construction agreement regarding our manufacturing facility based in Raleigh, North Carolina, where we committed to pay for construction work in the next year. Obligations under the terms of other agreements Calyxt entered into seed and grain production agreements (Forward Purchase Contracts) with seed producers and growers. The seed contracts often require Calyxt to pay prices for the seed produced at an exchange-traded price of grain plus a premium. The grower contracts are linked to a commodity futures market prices with the grower having the option to fix their price with us throughout the term of the agreement. These contracts allow for delivery of grain to Calyxt at harvest if so specified when the agreement is executed, otherwise delivery occurs on a date that Calyxt elects through August 31 of the following year. In all periods presented, we considered Forward Purchase Contracts as normal purchases and not derivatives. Any mark-to-market

Related parties

Related parties	12 Months Ended
	Dec. 31, 2019
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Related parties	Note 20 Key management personnel remuneration Key management personnel include members of the Board of Directors and the CODM as of December 31, 2019, as described in Note 3.5. Short-term employee benefits paid to key management personnel totaled to $3.6 million in the fiscal year 2017, $4.4 million in the fiscal year 2018 and $5.2 million in the fiscal year 2019. On September 4, 2014, the Board of Directors adopted a change of control plan which applies to the members of the CODM. This plan defines the conditions under which a severance package will be paid after a change of control of our company. Key management personnel employment agreements include a termination indemnity or additional post-employment compensation. Key management personnel received an aggregate of 602.000 securities in share-based remuneration (free shares and stock options) over the year ended December 31, 2019. The associated non-cash Other transactions with related parties Mr. Godard, a member of the Board of Directors, entered into two non-employee

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2019
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Subsequent events	Note 2 1 On February 18, 2020, Cellectis and Servier announced execution of a binding term sheet to amend the agreement signed between the two companies in 2019. On March 4, 2020, we and Servier entered into the definitive amendment contemplated by the term sheet, to grant to Servier an exclusive license limited to CD19 target, but extended to all gene-edited allogeneic CAR T-cell products targeting CD19 and gene edited exclusively by Cellectis’ TALEN. Under the amendment, Cellectis grants to Servier, an exclusive worldwide, royalty bearing license with sublicensing rights under certain conditions, under certain of our patents and know-how to develop, manufacture and commercialize gene-edited allogeneic CAR T-cell products targeting CD19 and gene edited exclusively by Cellectis’ TALEN. Servier, directly or through its sublicensees, will be s olely In addition, Servier confirms it will not pursue the development of five other targets for products using Cellectis technology and consequently Cellectis regains control over them. Promptly after the date of execution of the amendment, Servier shall make an upfront payment of million Euros. In addition, the Servier License Agreement provides for aggregate additional payments of up to $ million ( million Euros), comprising payments for certain specified development and commercial milestones. We are also eligible to receive flat low double-digit royalties based on annual net sales of commercialized products. We are also entitled to a low double-digit royalty on certain development milestone payments received by Servier under sublicenses.

Accounting principles (Policies

Accounting principles (Policies)	12 Months Ended
	Dec. 31, 2019
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Basis for preparation	2.1 Basis for preparation The Consolidated Financial Statements of Cellectis as of and for the year ended December 31, 2019 were approved by our Board of Directors on March 4, 2020. Our Consolidated Financial Statements are presented in U.S. dollars. See Note 2.4. The Consolidated Financial Statements have been prepared in accordance with International Financial Reporting Standards (“IFRS”) as issued by the International Accounting Standards Board (“IASB”) and in accordance The Consolidated Financial Statements have been prepared using the historical cost measurement basis except for certain assets and liabilities that are measured at fair value in accordance with IFRS. IFRS include International Financial Reporting Standards (“IFRS”), International Accounting Standards (“the IAS”), as well as the interpretations issued by the Standards Interpretation Committee (“the SIC”), and the International Financial Reporting Interpretations Committee (“IFRIC”). The significant accounting methods used to prepare the Consolidated Financial Statements are described below. Application of new or amended standards or new amendments The following pronouncements and related amendments have been adopted by us from January 1, 2019 but had no significant impact on the Consolidated Financial Statements: • Amendment to IFRS 9 “Financial Instruments – Prepayment Features with Negative Compensation” (applicable for periods beginning after January 1, 2019) • IFRIC 23 “Uncertainty over Income Tax Treatments” (applicable for periods beginning after January 1, 2019) • Amendment to IAS 28 “Long-term Interests in Associates and Joint Ventures” (applicable for periods beginning after January 1, 2019) • Amendment to IAS 19 “Plan Amendment, Curtailment or Settlement” (applicable for periods beginning after January 1, 2019) • Annual Improvements to IFRSs 2015–2017 Cycle (Amendments to IFRS 3, IFRS 11, IAS 12 and IAS 23, applicable for periods beginning after January 1, 2019) Standards, interpretations and amendments issued but not yet effective The following pronouncements and related amendments are applicable for first quarter accounting periods beginning after January 1, 2020. We do not anticipate that the adoption of these pronouncements and amendments will have a material impact on our results of operations, financial position or cash flows. • Amendments to References to the Conceptual Framework in IFRS Standards (Effective for the accounting periods as of January 1, 2020) • Amendment to IFRS 3 “Business Combinations” (Effective for the accounting periods as of January 1, 2020 and not yet adopted by the European Union) • Amendments to IAS 1 “Presentation of financial statements” and IAS 8 “Accounting policies, changes in accounting estimates and errors” (Effective for the accounting periods as of January 1, 2020) • Amendements to IFRS 9 “Financial instruments”, IAS 39 “Financial instruments: Recognition and Measurement” et IFRS 7 “Financial instruments: Disclosures” (Effective for the accounting periods as of January 1, 2020) - Interest Rate Benchmark Reform • IFRS 17 “Insurance Contracts” (applicable for periods beginning after January 1, 2021 and not yet adopted by the European Union)
IFRS16 application	2.2 IFRS16 application Since January 1, 2019, Cellectis has applied the new standard IFRS 16 “Leases”. Under this standard, a financial asset and a financial liability are recognized for Group leases that meet the standard’s criteria. The financial statements for prior periods have not been restated in accordance with the transition options of IFRS 16 elected by the Group since Cellectis has applied the modified retrospective approach. The Group uses the two capitalization exemptions provided by the standard: • lease contracts with a duration of less than 12 months ; • lease contracts for which the underlying asset has a low value, which has been defined by the Group to be below $5,000. The Group has also applied the following practical expedients at the transition date: • exclusion of initial direct costs from the measurement of the • accounting for leases for which the lease term ends within 12 months of the date of initial application as short-term leases • the carrying amount of the right-of-use The following discount rates have been applied: • building rental in Paris, France (discounting rate 2%), building rental in Roseville, Minnesota, USA and Raleigh, North Carolina, USA (discounting rate of 8%), building rental in New York, New York, USA (discounting rate of 4.4%), and equipment rental (discounting rate 1%). The main changes introduced by IFRS 16 are the following: Capitalization of the right-of-use Identified lease contracts mainly concern Cellectis’ Headquarters and R&D buildings in Paris, New York and Raleigh, North Carolina, USA and Calyxt’s Headquarters and its production and storage areas in Roseville, Minnesota, USA. For purposes of IFRS 16, the lease term reflects the Group’s reasonable expectation of the period during which the underlying asset will be used. The discount rate used to calculate the lease debt has been determined, for each portfolio of assets, according to the incremental borrowing rate at the transition date. The sale and lease-back agreement entered into by Calyxt in the third quarter of 2017 has a defined lease term and was classified as an operating lease agreement under IAS 17. According to IFRS 16, this lease receives the standard accounting treatment for operating leases existing at the date of initial application and the value of the right-of-use Accounting for the other assets leases: The main lease contracts identified correspond to office and laboratory equipment. The cumulative effect of initially applying IFRS 16 has been recognized as an adjustment to the opening balance sheet at the date of initial application, January 1, 2019, as presented in the table below: January 1, 2019 as IFRS 16 January 1, 2019 ASSETS Non-current Intangible assets 1,268 1,268 Property, plant, and equipment 10,041 (1,309 ) 8,732 Right-of-use — 37,569 37,569 Other non-current 1,891 1,891 Total non-current 13,199 36,260 49,460 Current assets Inventories 275 275 Trade receivables 2,971 2,971 Subsidies receivables 17,173 17,173 Other current assets 15,333 (2,139 ) 13,194 Current financial assets 388 388 Cash and cash equivalents 451,501 451,501 Total current assets 487,641 (2,139 ) 485,502 TOTAL ASSETS 500,840 34,121 534,961 LIABILITIES Shareholders’ equity Share capital 2,765 2,765 Premiums related to the share capital 828,525 828,525 Treasury share reserve — — Currency translation adjustment (16,668 ) (16,668 ) Retained earnings (deficit) (326,628 ) (326,628 ) Net income (loss) (78,693 ) (78,693 ) Total shareholders’ equity - Group Share 409,301 409,301 Non-controlling 40,970 40,970 Total shareholders’ equity 450,272 450,272 Non-current Non-current 1,018 31,720 32,737 Non-current 2,681 (639 ) 2,042 Total non-current 3,699 31,081 34,779 Current liabilities Current lease debts 333 3,743 4,076 Trade payables 15,883 15,883 Deferred revenues and contract liabilities 20,754 (299 ) 20,454 Current provisions 1,530 (403 ) 1,127 Other current liabilities 8,369 8,369 Total current liabilities 46,869 3,041 49,910 TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY 500,840 34,121 534,961 The rental charges relating to these leases – i.e. $4.0 million for the year ended December 31, 2019 – are replaced with the recognition of an amortization expense of $4.6 million and a financial expense of $2.6 million. The rental charges relating to short-term and low-value In the statement of cash flows, • rent paid on leases that meet the criteria of IFRS 16 are classified within financing activities as principal portion and interest payment on the lease debt, which was $3.4 million for the year ended December 31, 2019; and • short-term lease payments, payments for leases of low-value The table below explains the differences between Operating lease commitments disclosed under IAS 17 as of December 31, 2018, discounted using the incremental borrowing rate at the date of initial application, and Lease liabilities recognized in the statement of financial position at the date of initial application. Operating lease commitments disclosed under IAS 17 as of December 31, 2018 (in thousands): Sale and lease-back agreement $ 31,668 Facility lease agreements $ 28,230 Total $ 59,898 -Discounting impact & assumption changes $ (18,966 ) -Facility lease termination $ (4,220 ) -Other $ 101 Total lease debt $ 36,813 Use of judgment, estimates and assumptions: The application of IFRS 16 “Leases” requires the Group to make assumptions and estimates in order to determine the value of the right-of-use
Currency of the financial statements	2.3 Currency of the financial statements The Consolidated Financial Statements are presented in U.S. dollars, which differs from the functional currency of Cellectis, which is the euro. All financial information (unless indicated otherwise) is presented in thousands of U.S. dollars. The statements of financial position of consolidated entities having a functional currency different from the U.S. dollar are translated into U.S. dollars at the closing exchange rate (spot exchange rate at the statement of financial position date) and the statements of operations, statements of comprehensive income (loss) and statements of cash flows of such consolidated entities are translated at the average period to date exchange rate. The resulting translation adjustments are included in equity under the caption “Currency Translation Adjustments” in the Consolidated Statements of Changes in Shareholders’ Equity.
Basis of consolidation	2.4 Basis of consolidation Accounting policy We control all the legal entities included in the consolidation. An investor controls an investee when the investor is exposed to variable returns from its involvement with the investee, and has the ability to affect those returns through its power over the investee. Control requires power, exposure to variability of returns and a linkage between the two. To have power, the investor needs to have existing rights that give it the current ability to direct the relevant activities that significantly affect the investee’s returns. In order to ascertain control, potential voting rights which are substantial are taken into consideration. Consolidation of a subsidiary begins when the Group obtains control over the subsidiary and ceases when the Group loses control of the subsidiary. All intra-group assets and liabilities, equity, income, expenses and cash flows relating to transactions between members of the Group are eliminated in full consolidation. Consolidated entities For the year ended December 31, 2019, the consolidated group of companies (sometimes referred to as the “Group”) includes Cellectis S.A., Cellectis, Inc., Cellectis Biologics Inc., which was incorporated on January 18, 2019, and Calyxt, Inc. As of December 31, 2019, Cellectis S.A. owns 100% of Cellectis, Inc., which owns 100% of Cellectis Biologics, Inc., and approximately 68.9% of Calyxt’s outstanding shares of common stock. As of December 31, 2018, Cellectis S.A. owned 100% of Cellectis, Inc. and approximately 69.5% of Calyxt’s outstanding shares of common stock. Until July 25, 2017, Cellectis S.A. fully owned Calyxt, Inc. On July 25, 2017, Calyxt closed its IPO with $64.4 million in gross proceeds to Calyxt from the sale of 8,050,000 shares at $8 per share, including the full exercise of the underwriter’s over-allotment option and Cellectis’ purchase of $20.0 million of shares in the IPO. On May 22, 2018, Calyxt Inc completed a follow-on follow-on follow-on Non-controlling Non-controlling non-controlling follow-on
Foreign currency	2.5 Foreign currency Foreign currency transactions and balances Significant transactions in foreign currencies are translated into the respective functional currencies at the exchange rates effective at the transaction dates, otherwise the average rate of the previous month is used for non-significant The resulting exchange gains or losses are recorded in the consolidated statements of operations in financial gain (loss). Foreign currency translation The assets and liabilities of foreign operations having a functional currency different from the euro are translated into euros at the period end exchange rate. The income and expenses of foreign operations are translated into euros using the average exchange rate for the reporting period. Gains and losses arising from currency translation are recognized in other comprehensive loss. Consolidated financial statements are then converted into dollars using the method described in Note 2.4. The difference in effect of exchange rate changes on cash and cash equivalents between the statements of consolidated operations and consolidated cash flows is mainly explained by the following elements: • the differential between the average exchange rate and the period end rates applied to the cash flows of the period; • the differential between the opening exchange rates and the period end exchanges rate applied on our opening cash and cash equivalents balance denominated in dollars; and • the foreign exchange rate impact of the conversion of the financial statements of our US subsidiaries.
Use of judgment, estimates and assumptions	2.6 Use of judgment, estimates and assumptions The preparation of these consolidated financial statements requires management to make judgments, estimates and assumptions that affect the reported amounts of revenues, expenses, assets and liabilities, and the accompanying disclosures, including the disclosure of contingent liabilities. Actual amounts may differ from those estimates. The Group’s exposure to risks and uncertainties is disclosed in Note 8.3: Financial instruments risk management and policies. Estimates and assumptions The key assumptions concerning the future and other key sources of estimation uncertainty at the period end date, that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year, are described below. The Group based its assumptions and estimates on parameters available when the consolidated financial statements were prepared. Existing circumstances and assumptions about future developments, however, may change due to market changes or circumstances arising that are beyond the control of the Group. Such changes are reflected in the assumptions when they occur. • Revenue recognition – Note 3.1 • Share-based payments – Note 16 • Provisions for risks and charges – Note 18 • Right-of-use
Revenues and other income	3.1 Revenues and other income Accounting policies Collaboration agreements and licenses Under IFRS 15, “Revenue from contracts with customers”, revenue is recognized when Cellectis satisfies a performance obligation by transferring a distinct good or service (or a distinct bundle of goods and or/ services) to a customer, i.e. when the customer obtains control of these goods or services. We have entered into certain research and development collaboration agreements that consist of the licensing of rights to technology, research and development programs, research and development cost reimbursements and royalties. We have analyzed the agreements to identify the separate performance obligations. These collaboration agreements may generate cash flows through non-refundable non-cancelable, non-refundable co-contracting Up-front Research and development costs reimbursements are recognized on a time and material basis over the length of the specific research and development project. Milestone payments represent variable consideration, the receipt of which is dependent upon the achievement of certain scientific, regulatory, or commercial milestones. Such payments are considered variable consideration. We recognize milestone payments when it is highly probable that any revenue recognized will not be subsequently reversed. This includes consideration of whether the performance obligation is achieved and may be when the triggering event has occurred, depending on the nature of the triggering event, there are no further contingencies or services to be provided with respect to that event, and the co-contracting Royalty revenues arise from our contractual entitlement to receive a percentage of product sales achieved by co-contracting In addition, we license our technology to other third parties and revenues are recognized ratably over the period of the license agreements. Sales of products and services Revenues on sales of products are recognized once the control over the delivered products is transferred to the customer. Sales include shipping and handling charges if billed to the customer and are reported net of trade promotion and other costs, including estimated allowances for returns, unsalable product and prompt pay discounts. Sales, use, value-added and other excise taxes are not recognized in revenue. Trade promotions are recorded based on estimated participation and performance levels for offered programs at the time of sale. We generally do not allow a right of return. We also offer research services, which revenue is recognized over time, as the customer receives the benefits of the services. Research Tax Credit The main Research Tax Credit from which we benefit is the Crédit d’Impôt Recherche, We apply for CIR for research expenditures incurred in each fiscal year and recognize the amount claimed in the line item “Other income” in the same fiscal year. Research tax credit is subject to audit of tax authorities. When tax authorities’ payment related to CIR is late, default interests are applied and are recognized in “other income”.
Operating expenses	3.2 Operating expenses Accounting policies Prior to 2019, cost of goods sold represented immaterial costs associated with Calyxt’s out-licensing Royalty expenses correspond to costs from license agreements that we entered into to obtain access to technology that we use in our product development efforts. Depending on the contractual provisions, expenses are based either on a percentage of revenue generated by using the patents based on fixed annual royalties or conditioned by milestones. Research and development expenses include employee-related costs, laboratory consumables, materials supplies and facility costs, as well as fees paid to non-employees Selling, general and administrative expenses consist primarily of employee-related expenses for executive, business development, intellectual property, finance, legal and human resource functions. Administrative expenses also include facility-related costs and service fees, other professional services, recruiting fees and expenses associated with maintaining patents. We classify a portion of personnel and other costs related to information technology, human resources, business development, legal, intellectual property and general management in research and development expenses based on the time that each employee or person spent contributing to research and development activities versus sales, general and administrative activities.
Financial income and expenses	3.3 Financial income and expenses Accounting policies Financial income and financial expense include, in particular, the following: • Interest income from savings accounts and fixed term bank deposits; • Interest expense from leases; • Foreign exchange gain (loss) from transactions in foreign currencies; and • Other financial income and expenses, mainly derived from fair value adjustments related to our financial assets and derivative instruments.
Income tax	3.4 Income tax Accounting policies Income tax (expense or income) comprises current tax expense (income) and deferred tax expense (income). Deferred taxes are recognized for all the temporary differences arising from the difference between the tax basis and the accounting basis of assets and liabilities. Tax losses that can be carried forward or backward may also be recognized as deferred tax assets. Tax rates that have been enacted as of the closing date are utilized to determine deferred tax. Deferred tax assets are recognized only to the extent that it is likely that future profits will be sufficient to recover them. We have not recorded deferred tax assets or liabilities in the statements of financial position.
Reportable segments	3.5 Reportable segments Accounting policies Reportable segments are identified as components of the Group that have discrete financial information available for evaluation by the Chief Operating Decision Maker (“CODM”), for purposes of performance assessment and resource allocation. Cellectis’ CODM is composed of: • The Chairman and Chief Executive Officer; • The Chief Operating Officer (through July 24, 2019); • The Executive Vice President Technical Operation (beginning July 22, 2019); • The Executive Vice President Strategic Initiatives; • The Executive Vice President Global Quality (beginning July 22, 2019); • The Chief Scientific Officer; • The Chief Financial Officer; • The General Counsel; • The VP Corporate Development (beginning November, 2019); and • The Chief Regulatory & Compliance Officer. We view our operations and manage our business in two operating and reportable segments that are engaged in the following activities: • Therapeutics: • Plants: There are inter-segment transactions between the two reportable segments, including allocation of corporate general and administrative expenses by Cellectis S.A. and allocation of research and development expenses to the reportable segments. With respect to corporate general and administrative expenses, Cellectis S.A. has provided Calyxt, Inc. with general sales and administrative functions, accounting and finance functions, investor relations, intellectual property, legal advice, human resources, communication and information technology under a Management Services Agreement. As of December 31, 2019, Calyxt has internalized nearly all of the services previously provided by Cellectis under this agreement. Under the Management Services Agreement, Cellectis S.A. charges Calyxt, Inc. in euros at cost plus a mark-up 12-month The intersegment revenues represent the transactions between segments. Intra-segment transactions are eliminated within a segment’s results and intersegment transactions are eliminated in consolidation as well as in key performance indicators by reportable segment. Information related to each reportable segment is set out below. Segment revenues and other income, Research and development expenses, Selling, general and administrative expenses, and Cost of revenue and other operating income and expenses, and Adjusted net income (loss) attributable to shareholders of Cellectis (which does not include non-cash Adjusted Net Income (Loss) attributable to shareholders of Cellectis S.A. is not a measure calculated in accordance with IFRS. Because Adjusted Net Income (Loss) attributable to shareholders of Cellectis excludes Non-cash non-cash The net income (loss) includes the impact of the operations between segments while the intra-segment operations are eliminated.
Impairment tests	Accounting policy Amortizable intangible assets, depreciable tangible assets and right-of-use Our cash-generating units (“CGUs”) correspond to the operating/reportable segments: Therapeutics and Plants.
Intangible assets	Accounting policy Capitalization of development expenses In accordance with IAS 38 Intangible Assets • technical feasibility necessary for the completion of the development project; • intention on our part to complete the project and to utilize it; • capacity to utilize the intangible asset; • proof of the probability of future economic benefits associated with the asset; • availability of the technical, financial, and other resources for completing the project; and • reliable evaluation of the development expenses. Other intangible assets The other intangible assets we acquired with definite useful lives are recognized at cost less accumulated amortization and impairment. Amortization expense is recorded on a straight-line basis over the estimated useful lives of the intangible assets, in the line Research and Development expenses or Selling, general and administrative expenses of the Statement of Consolidated Operations, depending on the use of the related asset. The estimated useful lives are as follows: • Software: from 1 3 • Patents: amortized from acquisition until legal protection expires, maximum of 20
Property, plant and equipment	Accounting policy Property, plant and equipment are recognized at acquisition cost less accumulated depreciation and any impairment losses. Acquisition costs include expenditures that are directly attributable to the acquisition of the asset and costs to ready it for use. Depreciation is expensed on a straight-line basis over the estimated useful lives of the assets. If components of property, plant and equipment have different useful lives, they are accounted for separately. The estimated useful lives are as follows: • Buildings and other outside improvements 10-20 • Leasehold improvements 5-10 • Office furniture 10 years • Laboratory equipment 3-10 • Office equipment 5 years • IT equipment 3 years Depreciation methods, useful lives and residual values are reviewed at each reporting date and adjusted, if appropriate. Any gain or loss on disposal of an item of property, plants and equipment is determined by comparing the proceeds from disposal with the carrying amount of the item. The net amount is recognized in the statement of consolidated operations under the line item “Other operating income and expenses.” Before IFRS 16 adoption as of January 1, 2019, payments made under operating leases were expensed on a straight-line basis over the term of the lease. Lease incentives received were recognized as an integral part of the total lease expense, over the term of the lease. If, according to the terms of a lease, it appeared that substantially all the risks and rewards incidental to ownership were transferred from the lessor to the lessee, the associated leased assets were initially recognized as an asset at the lower of their fair value and the present value of the minimum lease payments and subsequently depreciated or impaired, as necessary. The associated financial obligations were reported in the line item “non-current
Financial assets and liabilities	8 The new standard IFRS 9 “Financial instruments” is of mandatory application since January 1, 2018. Cellectis elected not to restate the 2016 and 2017 comparative periods, as authorized by the standard. Such adoption did not lead to any adjustment recorded in the Group opening equity at January 1, 2018. IFRS 9 comprises three phases: classification and measurement of financial assets and liabilities, impairment of financial assets and hedge accounting. Cellectis was not affected by the new classification required by the standard to determine the way financial assets are recognized and measured. Financial assets Under IFRS 9, Cellectis holds either: • financial assets measured at amortized cost or; • financial assets measured at fair value through profit or loss. Non-current Current financial assets correspond to investments and are recorded at fair value through profit and loss, which is the nominal value of the investment adjusted with the daily mark-to-market Trade and other receivables are recorded at fair value, which is the nominal value of invoices unless payment terms require a material adjustment for the time value discounting effect at market interest rates. Trade receivables are subsequently measured at amortized cost. A provision for expected credit losses for trade and other receivables is recognized if their recoverable amount is less than their carrying amount. The introduction of a new expected loss model for impairment of financial assets under IFRS 9 had no significant impact on the initial recognition of Cellectis trade and other receivables. Receivables are classified as current assets, except for those with a maturity exceeding 12 months after the reporting date. Government grants to Cellectis related to research and development expenses for research programs are recognized as subsidies receivables in the period in which the expenses subject to the subsidy have been incurred, provided there is a reasonable assurance that we will comply with conditions attached to the subsidy and that the subsidy will be received. Financial liabilities The application of IFRS 9 has no impact on the Cellectis’ accounting policy regarding financial liabilities. Financial liabilities include trade and other payables, finance leases and conditional advances. We initially recognize financial liabilities on the transaction date, which is the date that we become a party to the contractual provisions of the instrument. We derecognize financial liabilities when our contractual obligations are discharged, canceled or expire. Financial liabilities are valued at amortized cost. The amount of interest recognized in financial expenses is calculated by applying the financial liability’s effective interest rate to its carrying amount. Any difference between the expense calculated using the effective interest rate and the actual interest payment impacts the value at which the financial liability is recognized. Liabilities for short term employee benefits are included in financial liabilities. They are recognized for the amount expected to be paid under short-term cash bonus or profit-sharing plans if we have a present legal or constructive obligation to pay the amount as a result of past service provided by the employee, and the obligation can be estimated reliably.
Inventories	Accounting policy Inventories are measured at the lower of cost and net realizable value. Cost is determined using the first in first out cost method. They include all costs of seed production and grain Calyxt purchases as well as costs to store, transport and process the grain into finished products. Consideration Calyxt receives from growers when they purchase seed is recorded as a reduction of inventory. Calyxt evaluates inventory balances for obsolescence on a regular basis using projected selling prices for our products, market prices for the underlying agricultural markets, the age of products and other factors that take into consideration our limited operating history. Prior to the commercialization of Caly x t's Description of inventories As of December 31, 2019, inventories amounted to $2.9 million, $2.6 million of which related to Calyxt’s grain and seed costs, and $0.3 million to raw materials and laboratory consumables (representing pharmaceutical and chemical products). As of December 31, 2018, inventories consisted of $0.3 million of raw materials and laboratory consumables (representing pharmaceutical and chemical products). No provision for impairment has been recorded as of December 31, 2019 and 2018.
Current financial assets	1 1 Accounting policies Current financial assets include current restricted cash and other current financial assets. As of December 31, 2019, restricted cash consists of: i. deposit to secure commitment to supplier regarding the manufacturing facility construction for $ 20 ii. deposits to secure a Calyxt furniture and equipment sale-leaseback for $ 1.5 0.4 As of December 31, 2018, restricted cash consists of deposits to secure a Calyxt furniture and equipment sale-leaseback for $1.5 million of which $0.4 million are classified as short-term restricted cash. Financial assets are measured at fair value through profit or loss in accordance with IAS 39 include the following: • Financial assets including embedded derivatives for which Cellectis elected to designate at fair value through profit or loss; • Financial assets managed on a fair value basis; and • Derivative instruments that are not documented in hedging relationships. IFRS 13 (Fair Value Measurement) requires counterparty and own credit risk to be taken into account when measuring the fair value of financial instruments. This risk is estimated on the basis of observable, publicly-available statistical data.
Cash and cash equivalents	1 1 Accounting policy Cash and cash equivalents are held for the purpose of meeting short-term cash commitments rather than for the purpose of investment or for other purposes. They are readily convertible into a known amount of cash and are subject to an insignificant risk of changes in value. Cash and cash equivalents include cash, bank accounts, money market funds and fixed bank deposits that meet the definition of a cash equivalent. Cash equivalents are fair valued at the end of each reporting period.
Share capital issued	Accounting policy Share capital comprises ordinary shares and shares with double voting rights classified in equity. Costs directly attributable to the issue of ordinary shares or share options are recognized as a reduction in equity. Repurchased own shares are classified as treasury shares and deducted from equity.
Earnings per share	Accounting policy Basic earnings per share are calculated by dividing profit attributable to our ordinary shareholders by the weighted average number of ordinary shares outstanding during the period, adjusted to take into account the impact of treasury shares. Diluted earnings per share is calculated by adjusting profit attributable to ordinary shareholders and the weighted average number of ordinary shares outstanding, for the effects of all potentially dilutive ordinary shares (stock-options, free shares, share warrants, employee warrants).
Provisions	Accounting policy A provision is recognized if, as a result of a past event, we have a present legal or constructive obligation that can be estimated reliably, and it is probable that an outflow of economic benefits will be required to settle the obligation. The amount recognized as a provision is the best estimate of the expenditure required to settle the present obligation at the reporting date. Provisions for retirement and other benefits Our defined benefit obligations, and their cost, are determined using the projected unit credit method. The method consists in measuring the obligation based on a projected end-of-career Actuarial assumptions used to determine the benefit obligations are specific to each country and each benefit plan. The discount rate used is the yield at the reporting date on AA credit-rated bonds with maturity dates that approximate the expected payments for our obligations. Actuarial gains or losses are recognized in the statement of comprehensive loss for the year in which they occur.
Commitments	Accounting policy The commitment amounts are associated with contracts that are enforceable and legally binding and that specify all significant terms, including fixed or minimum services to be used, fixed, minimum or variable price provisions, and the approximate timing of the actions under the contracts. They do not include obligations under agreements that we can cancel without a significant penalty.

Accounting principles (Tables)

Accounting principles (Tables)	12 Months Ended
	Dec. 31, 2019
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Schedule Of Information About Lease Assets And Liabilities	The cumulative effect of initially applying IFRS 16 has been recognized as an adjustment to the opening balance sheet at the date of initial application, January 1, 2019, as presented in the table below: January 1, 2019 as IFRS 16 January 1, 2019 ASSETS Non-current Intangible assets 1,268 1,268 Property, plant, and equipment 10,041 (1,309 ) 8,732 Right-of-use — 37,569 37,569 Other non-current 1,891 1,891 Total non-current 13,199 36,260 49,460 Current assets Inventories 275 275 Trade receivables 2,971 2,971 Subsidies receivables 17,173 17,173 Other current assets 15,333 (2,139 ) 13,194 Current financial assets 388 388 Cash and cash equivalents 451,501 451,501 Total current assets 487,641 (2,139 ) 485,502 TOTAL ASSETS 500,840 34,121 534,961 LIABILITIES Shareholders’ equity Share capital 2,765 2,765 Premiums related to the share capital 828,525 828,525 Treasury share reserve — — Currency translation adjustment (16,668 ) (16,668 ) Retained earnings (deficit) (326,628 ) (326,628 ) Net income (loss) (78,693 ) (78,693 ) Total shareholders’ equity - Group Share 409,301 409,301 Non-controlling 40,970 40,970 Total shareholders’ equity 450,272 450,272 Non-current Non-current 1,018 31,720 32,737 Non-current 2,681 (639 ) 2,042 Total non-current 3,699 31,081 34,779 Current liabilities Current lease debts 333 3,743 4,076 Trade payables 15,883 15,883 Deferred revenues and contract liabilities 20,754 (299 ) 20,454 Current provisions 1,530 (403 ) 1,127 Other current liabilities 8,369 8,369 Total current liabilities 46,869 3,041 49,910 TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY 500,840 34,121 534,961
Information About Operating Lease Commitments Under IAS17	Operating lease commitments disclosed under IAS 17 as of December 31, 2018 (in thousands): Sale and lease-back agreement $ 31,668 Facility lease agreements $ 28,230 Total $ 59,898 -Discounting impact & assumption changes $ (18,966 ) -Facility lease termination $ (4,220 ) -Other $ 101 Total lease debt $ 36,813

Information concerning the Gr_2

Information concerning the Group's Consolidated Operations (Tables)	12 Months Ended
	Dec. 31, 2019
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Revenues By Country of Origin and Other Income	Revenues by country of origin and other income For 2017 2018 2019 $ in thousands From France 24,680 12,495 7,896 From USA 508 236 7,294 Revenues 25,188 12,731 15,190 Research tax credit 8,327 8,561 7,800 Subsidies and other 201 140 — Other income 8,528 8,701 7,800 Total revenues and other income 33,715 21,432 22,990
Revenues by Nature	Revenues by nature For 2017 2018 2019 $ in thousands Recognition of previously deferred upfront payments 14,875 7,114 — Other revenues 7,945 3,383 6,055 Collaboration agreements 22,821 10,497 6,055 Licenses 2,270 2,142 1,762 Products & services 97 92 7,373 Total revenues 25,188 12,731 15,190
Details of Operating Expenses by Nature	Details of operating expenses by nature F 2017 2018 2019 $ in thousands Cost of revenue Cost of good sold — — (9,280 ) Royalty expenses (2,620 ) (2,739 ) (2,112 ) Cost of revenue (2,620 ) (2,739 ) (11,392 ) For 2017 2018 2019 $ in thousands Research and development expenses Wages and salaries (12,986 ) (16,452 ) (21,294 ) Social charges on free shares and stock option grants (1,088 ) (99 ) (1,357 ) Non-cash (23,832 ) (18,057 ) (12,260 ) Personnel expenses (37,906 ) (34,608 ) (34,911 ) Purchases and external expenses (38,458 ) (40,458 ) (49,251 ) Other (2,863 ) (1,501 ) (7,880 ) Total research and development expenses (79,227 ) (76,567 ) (92,042 ) For 2017 2018 2019 $ in thousands Selling, general and administrative expenses Wages and salaries (7,019 ) (11,373 ) (12,822 ) Social charges on free shares and stock option grants (881 ) (29 ) (491 ) Non-cash (26,586 ) (19,161 ) (14,621 ) Personnel expenses (34,486 ) (30,563 ) (27,934 ) Purchases and external expenses (9,138 ) (14,251 ) (11,431 ) Other (1,126 ) (2,433 ) (3,652 ) Total selling, general and administrative expenses (44,750 ) (47,248 ) (43,017 ) For 2017 2018 2019 $ in thousands Personnel expenses Wages and salaries (20,005 ) (27,825 ) (34,116 ) Social charges on free shares and stock option grants (1,969 ) (128 ) (1,848 ) Non-cash (50,418 ) (37,218 ) (26,881 ) Total personnel expenses (72,392 ) (65,171 ) (62,845 )
Details of Financial Income and Expenses	Details of financial income and expenses For 2017 2018 2019 Interest income 1,974 6,787 6,985 Foreign exchange gain 1,185 13,597 4,481 Other financial revenues 4,102 188 505 Total financial revenues 7,262 20,572 11,971 Interest expenses — (39 ) (3 ) Interest expenses for lease s (4 ) (7 ) (2,603 ) Foreign exchange loss (17,734 ) (3,090 ) (671 ) Other financial expenses (556 ) (677 ) (354 ) Total financial expenses (18,294 ) (3,813 ) (3,631 ) Total (11,032 ) 16,758 8,340
Disclosure of Income Tax (Expense or Income)	Tax proof For the year ended December 31, 2017 2018 2019 $ in thousands Income (loss) before taxes from continuing operations (103,683 ) (88,333 ) (115,212 ) Theoretical group tax rate 34.43 % 23.66 % 25.35 % Theoretical tax benefit (expense) 35,698 20,901 29,208 Increase/decrease in tax benefit arising from: Permanent differences 293 832 (1,131 ) Research tax credit 2,926 2,079 2,786 Share-based compensation & other IFRS adjustments (8,297 ) (8,065 ) (7,828 ) Non recognition of deferred tax assets related to tax losses and temporary differences (30,713 ) (15,652 ) (23,079 ) Other differences 92 (95 ) 43 Effective tax expense — — — Effective tax rate 0.00 % 0.00 % 0.00 %
Disclosure of Deferred Tax Assets and Liabilities	Deferred tax assets and liabilities As of December 31, 2017 2018 2019 $ in thousands Credits and net operating loss carryforwards 51,640 65,555 102,112 Pension commitments 548 569 714 Leases (12 ) (4 ) 47 Impairment of assets 10 10 1 Revenue recognition — 200 197 Other 604 491 284 Total unrecognized deferred tax assets, net (52,790 ) (66,823 ) (103,354 )
Summary of Key Performance Indicators by Reportable Segments	Details of key performance indicators by reportable segment $ in thousands For the year ended December 31, 2017 For the year ended December 31, 2018 For the year ended December 31, 2019 Plants Therapeutics Total Plants Therapeutics Total Plants Therapeutics Total External revenues 508 24,680 25,188 236 12,495 12,731 7,294 7,896 15,190 External other income 239 8,290 8,528 178 8,523 8,701 — 7,800 7,800 External revenues and other income 747 32,969 33,715 414 21,018 21,432 7,294 15,696 22,990 Cost of revenue (390 ) (2,230 ) (2,620 ) (595 ) (2,144 ) (2,739 ) (9,275 ) (2,117 ) (11,392 ) Research and development expenses (6,057 ) (73,170 ) (79,227 ) (8,638 ) (67,929 ) (76,567 ) (12,390 ) (79,652 ) (92,042 ) Selling, general and administrative expenses (13,143 ) (31,607 ) (44,750 ) (21,067 ) (26,180 ) (47,248 ) (26,090 ) (16,927 ) (43,017 ) Other operating income and expenses 6 225 232 (50 ) 81 31 25 (116 ) (91 ) Total operating expenses (19,584 ) (106,782 ) (126,366 ) (30,351 ) (96,172 ) (126,523 ) (47,730 ) (98,812 ) (146,542 ) Operating income (loss) before tax (18,837 ) (73,813 ) (92,650 ) (29,937 ) (75,154 ) (105,091 ) (40,436 ) (83,116 ) (123,552 ) Financial gain (loss) — (11,032 ) (11,032 ) 1,420 15,339 16,758 294 8,045 8,340 Net income (loss) (18,837 ) (84,846 ) (103,683 ) (28,517 ) (59,816 ) (88,333 ) (40,142 ) (75,071 ) (115,212 ) Non controlling interests 4,315 — 4,315 9,640 — 9,640 13,121 — 13,121 Net income (loss) attributable to shareholders of Cellectis (14,522 ) (84,846 ) (99,368 ) (18,877 ) (59,816 ) (78,693 ) (27,021 ) (75,071 ) (102,091 ) R&D non-cash 967 22,623 23,590 838 16,852 17,689 1,619 10,010 11,629 SG&A non-cash 4,990 20,345 25,335 5,218 11,655 16,873 6,673 4,940 11,613 Adjustment of share-based compensation attributable to shareholders of Cellectis 5,957 42,968 48,925 6,056 28,507 34,563 8,292 14,950 23,242 Adjusted net income (loss) attributable to shareholders of Cellectis (8,565 ) (41,877 ) (50,442 ) (12,821 ) (31,309 ) (44,130 ) (18,729 ) (60,121 ) (78,849 ) Depreciation and amortization (551 ) (2,820 ) (3,371 ) (637 ) (1,740 ) (2,377 ) (1,233 ) (5,642 ) (6,875 ) Additions to tangible and intangible assets 792 1,849 2,642 1,871 3,040 4,911 2,998 14,668 17,666 Impairment of tangible assets — (798 ) (798 ) — — — — — —

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2019
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Details Information About Intangible Assets	Details of intangible assets $ in thousands Software and Patents Assets under construction Total Net book value as of January 1, 2017 924 419 1,343 Change in scope — — — Additions to intangible assets 6 135 141 Depreciation expense (231 ) — (231 ) Translation adjustments 112 66 178 Net book value as of December 31, 2017 811 619 1,431 Gross value at end of period 2,571 517 3,190 Accumulated depreciation and impairment at end of period (1,759 ) — (1,759 ) Net book value as of January 1, 2018 811 619 1,431 Change in scope — — — Additions to intangible assets 14 103 117 Disposal of intangible assets (7 ) — (7 ) Reclassification 6 — 6 Depreciation expense (217 ) — (217 ) Translation adjustments (30 ) (31 ) (61 ) Net book value as of December 31, 2018 577 691 1,268 Gross value at end of period 2,454 691 3,146 Accumulated depreciation and impairment at end of period (1,878 ) — (1,878 ) Net book value as of January 1, 2019 577 691 1,268 Change in scope — — — Additions to intangible assets 84 (2 ) 82 Disposal of intangible assets (50 ) — (50 ) Reclassification 6 — 6 Depreciation expense (174 ) — (174 ) Translation adjustments (12 ) (12 ) (24 ) Net book value as of December 31, 2019 431 677 1,108 Gross value at end of period 2,448 677 3,125 Accumulated depreciation and impairment at end of period (2,017 ) — (2,017 )

Right-of-use assets (Tables)

Right-of-use assets (Tables)	12 Months Ended
	Dec. 31, 2019
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Disclosure Of Detailed Information About Breakdown Of Right Of Use Assets Explanatory	The breakdown of right-of-use Building lease Office and Total $ in thousands Net book value as of January 1, 2019 as restated 36,061 1,508 37,569 Additions 11,357 1,516 12,873 Depreciation expense (4,058 ) (520 ) (4,578 ) Translation adjustments (248 ) (4 ) (252 ) Net book value as of December 31, 2019 43,112 2,500 45,612 Gross value at end of period 47,175 3,153 50,328 Accumulated depreciation at end of period (4,063 ) (653 ) (4,716 )

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Summary of Property Plant and Equipment Estimated Useful Lives	The estimated useful lives are as follows: • Buildings and other outside improvements 10-20 • Leasehold improvements 5-10 • Office furniture 10 years • Laboratory equipment 3-10 • Office equipment 5 years • IT equipment 3 years
Details of Property, Plant and Equipment	Details of property, plant and equipment Lands and Technical Fixtures, Assets under Total $ in thousands Net book value as of January 1, 2017 12,436 2,858 707 898 16,900 Additions to tangible assets 718 701 203 878 2,501 Disposal of tangible assets (9,243 ) (103 ) 2 (109 ) (9,453 ) Reclassification 14 47 18 (79 ) — Depreciation expense (972 ) (1,126 ) (245 ) (798 ) (3,140 ) Translation adjustments 206 127 68 18 418 Net book value as of December 31, 2017 3,159 2,505 753 809 7,226 Gross value at end of period 6,936 12,114 1,447 1,606 22,103 Accumulated depreciation and impairment at end of period (3,777 ) (9,609 ) (693 ) (798 ) (14,877 ) Net book value as of January 1, 2018 3,159 2,505 753 809 7,226 Additions to tangible assets 879 1,622 1,820 1,942 6,263 Disposal of tangible assets — (49 ) (690 ) (426 ) (1,164 ) Reclassification 39 216 793 (1,053 ) (6 ) Depreciation expense (758 ) (854 ) (478 ) — (2,091 ) Translation adjustments (90 ) (46 ) (27 ) (25 ) (188 ) Net book value as of December 31, 2018 3,229 3,393 2,172 1,247 10,041 Gross value at end of period 7,604 13,297 3,215 2,045 26,160 Accumulated depreciation and impairment at end of period (4,375 ) (9,903 ) (1,043 ) (798 ) (16,119 ) Net book value as of January 1, 2019 as restated* 3,229 2,084 2,172 1,247 8,732 Additions to tangible assets 318 374 329 16,563 17,584 Disposal of tangible assets — (10 ) (1 ) (419 ) (430 ) Reclassification 15 1,974 630 (2,624 ) (5 ) Depreciation expense (192 ) (1,247 ) (684 ) — (2,123 ) Translation adjustments (40 ) (15 ) (11 ) 20 (46 ) Net book value as of December 31, 2019 3,330 3,160 2,435 14,787 23,712 Gross value at end of period 7,833 13,962 4,149 15,585 41,529 Accumulated depreciation and impairment at end of period (4,503 ) (10,802 ) (1,714 ) (798 ) (17,817 )

Financial assets and liabilit_2

Financial assets and liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Summary of Financial Assets and Liabilities	The following table shows the carrying amounts and fair values of financial assets and financial liabilities. Accounting category Book value on the Fair Value 2018 Fair value through Amortized cost $ in thousands Financial assets Non-current — 1,891 1,891 1,891 Trade receivables — 2,971 2,971 2,971 Subsidies receivables — 17,173 17,173 17,173 Current financial assets 7 381 388 388 Cash and cash equivalents 451,501 — 451,501 451,501 Total financial assets 451,508 22,416 473,924 473,924 Financial liabilities Non-current — 1,018 1,018 1,018 Current financial liabilities — 333 333 333 Trade payables — 15,883 15,883 15,883 Other current liabilities — 8,369 8,369 8,369 Total financial liabilities — 25,603 25,603 25,603 Accounting category Book value on the Fair Value 2019 Fair value through Amortized cost $ in thousands Financial assets Non-current — 5,517 5,517 5,517 Trade receivables — 2,959 2,959 2,959 Subsidies receivables — 9,140 9,140 9,140 Current financial assets — 20,385 20,385 20,385 Cash and cash equivalents 340,522 — 340,522 340,522 Total financial assets 340,522 38,001 378,523 378,523 Financial liabilities Non-current — 46,540 46,540 46,540 Current financial liabilities — 1,067 1,067 1,067 Trade payables — 29,264 29,264 29,264 Other current liabilities — 8,497 8,497 8,497 Total financial liabilities — 85,368 85,368 85,368

Trade receivables and other c_2

Trade receivables and other current assets (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Disclosure of Trade Receivables	10 As of December 31, As of December 31, 2018 2019 $ in thousands Trade receivables 3,353 3,513 Valuation allowance (382 ) (554 ) Total net value of trade receivables 2,971 2,959
Disclosure of Subsidies Receivables	10 As of December 31, As of December 31, 2018 2019 $ in thousands Research tax credit 16,842 9,140 Other subsidies 1,598 — Valuation allowance for other subsidies (1,266 ) — Total subsidies receivables 17,173 9,140
Disclosure of Other Current Assets	10 As of December 31, As of December 31, 2018 2019 $ in thousands VAT receivables 1,679 3,044 Prepaid expenses and other prepayments 10,985 11,829 Tax and social receivables 244 150 Deferred expenses and other current assets 2,425 594 Total other current assets 15,333 15,617

Current financial assets and _2

Current financial assets and Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Summary of Current Financial Assets and Cash and Cash Equivalents	As of December 31, 2018 Carrying amount Unrealized Gains/(Losses) Estimated fair value $ in thousands Current financial assets 388 — 388 Cash and cash equivalents 451,501 — 451,501 Current financial assets and cash and cash equivalents 451,889 — 451,889 As of December 31, 2019 Carrying amount Unrealized Gains/(Losses) Estimated fair value $ in thousands Current financial assets 20,385 — 20,385 Cash and cash equivalents 340,522 — 340,522 Current financial assets and cash and cash equivalents 360,907 — 360,907
Details of Cash and Cash Equivalents	Details of cash and cash equivalents As of December 31, As of December 31, 2018 2019 $ in thousands Cash and bank accounts 398,178 270,630 Money market funds 13,248 13,722 Fixed bank deposits 40,075 56,170 Total cash and cash equivalents 451,501 340,522

Financial liabilities (Tables)

Financial liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Detail of financial liabilities	Detail of financial liabilities As of December 31, As of December 31, 2018 2019 $ in thousands Lease debt s / Finance lease 1,018 46,540 Total non-current 1,018 46,540 Lease debt s / Fina nce lease 333 1,067 Total current financial liabilities 333 1,067 Trade payables 15,883 29,264 Other current liabilities 8,369 8,497 Total Financial liabilities 25,603 85,368
Due dates of the financial liabilities	Due dates of the financial liabilities Balance as of December 31, 2019 Discounted amount Less than One One to Five More than Five $ in thousands L debts 47,607 1,067 46,540 — Financial liabilities 47,607 1,067 46,540 — Trade payables 29,264 29,264 — — Other current liabilities 8,497 8,497 — Total financial liabilities 85,368 38,828 46,540 —

Other current liabilities (Tabl

Other current liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Summary of Other Current Liabilities	As of December 31, As of December 31, 2018 2019 $ in thousands VAT Payables 291 130 Accruals for personnel related expenses 7,041 7,295 Other 1,037 1,072 Total 8,369 8,497

Deferred revenues and contrac_2

Deferred revenues and contract liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Details of Deferred Revenues and Contract Liabilities	Details of deferred revenues and deferred income As of December 31, 2018 As of December 31, 2019 $ in thousands Deferred revenues and c ontract liab ilities 20,454 20,033 Others 299 — Total Deferred revenue and contract liabilities 20,754 20,033

Capital (Tables)

Capital (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Schedule of Classes of Share Capital	Nature of the Transactions Share Capital Share premium Number of shares Nominal value $ in thousands in $ Balance as of January 1, 2017 2,332 568,185 35,335,060 0.05 Capital Increase 26 — 466,950 — Exercise of share warrants, employee warrants and stock options 9 2,921 158,052 — Non-cash — 42,968 — — Other movements — (37 ) — — Balance as of December 31, 2017 2,367 614,037 35,960,062 0.05 Capital Increase 379 178,230 6,146,000 — Exercise of share warrants, employee warrants and stock options 19 7,751 324,007 — Non-cash — 28,507 — — Balance as of December 31, 2018 2,765 828,525 42,430,069 0.05 Capital Increase 0 0 0 0 Exercise of share warrants, employee warrants and stock options 0 0 0 0 Non-cash 0 0 0 0 Other movements 0 0 0 0 Balance as of December 31, 2019 0 0 0 0
Schedule of Share Warrants and Non-employee Warrants	Date Type Number of Number of Number of Number of Number of Maximum of shares to be issued Number of Strike price per 07/27/2010 BSPCE E 19,702 — — — 19,702 20,464 19,702 7.97 05/18/2015 Free shares 15,600 — 15,600 — — — — — 03/24/2015 Stock Options 1,730,646 — — 117,652 1,612,994 1,612,994 1,612,994 38.45 03/27/2015 BSA 130,000 — — — 130,000 130,000 130,000 38.45 05/18/2015 BSA 50,000 — — — 50,000 50,000 50,000 29.58 09/08/2015 BSA 224,200 — — — 224,200 224,200 224,200 28.01 09/08/2015 Stock Options 1,770,000 — — 146,800 1,623,200 1,623,200 1,623,200 27.55 03/14/2016 BSA 147,025 — — 147,025 147,025 147,025 27.37 03/14/2016 Stock Options 1,785,271 — — 132,676 1,652,595 1,652,595 1,549,308 22.44 10/28/2016 BSA 148,000 — — 148,000 148,000 148,000 18.68 10/28/2016 Stock Options 2,369,689 — — 190,796 2,178,893 2,178,893 1,634,170 17.90 10/11/2017 BSA 200,000 — — — 200,000 200,000 133,333 24.34 10/11/2017 Stock Options 1,182,500 — — 222,500 960,000 960,000 480,000 22.57 10/08/2018 Free shares 43,000 — 20,000 20,000 3,000 3,000 — — 10/08/2018 Stock Options 100,000 — — 50,000 50,000 50,000 12,500 24.80 12/17/2018 Free shares 13,000 — — — 13,000 13,000 — — 12/17/2018 Stock Options 40,000 — — — 40,000 40,000 10,000 18.37 07/03/2019 Free shares — 3,500 — 1,000 2,500 2,500 — — 07/03/2019 Stock Options — 3,000 — 3,000 — — — 15.69 04/24/2019 Stock Options — 1,562,800 — 93,100 1,469,700 1,469,700 — 18.25 04/24/2019 Free shares — 6,500 — — 6,500 6,500 — — 07/16/2019 Free shares — 9,000 — 5,000 4,000 4,000 — — 11/06/2019 Stock Options — 55,000 — — 55,000 55,000 — 11.06 11/06/2019 Free shares — 21,500 — — 21,500 21,500 — — 11/18/2019 Stock Options — 30,000 — — 30,000 30,000 — 12.33 11/18/2019 Free shares — 16,500 — — 16,500 16,500 — — Total 9,968,633 1,707,800 35,600 982,524 10,658,309 10,659,071 7,774,432
Schedule of Information Relating to Subsidiaries that Reported Non-Controlling Interest	The following table summarizes the information relating to each of our subsidiaries that reported non-controlling CALYXT 201 8 201 9 $ in thousands Revenue 236 7,294 Net Profit (Loss) (28,517 ) (40,142 ) Net Profit (Loss) attributable to NCI (9,640 ) (13,121 ) Other comprehensive income (5,373 ) (1,237 ) Total comprehensive income (33,891 ) (41,378 ) Total comprehensive income attributable to NCI (10,330 ) (12,856 ) Current assets 97,735 63,528 Non-current 4,539 22,518 Current liabilities 5,460 6,642 Non-current 8 26 15,121 Net assets 95,987 64,283 Net assets attributable to NCI 29,257 19,973

Share-based payments (Tables)

Share-based payments (Tables)	12 Months Ended
	Dec. 31, 2019
Warrants [member]
Statement [Line Items]
Summary of Information on Stock Option Activity	Information on warrants activity follows: Warrants Weighted- Warrants Weighted- Remaining Balance as of December 31, 201 7 469,436 28.80 € 1,100,969 27.23 € 8.2y Granted 0 0.00 € Exercised (1,867 ) 6.16 € Forfeited or Expired (180,175 ) 29.95 € Balance as of December 31, 201 8 687,252 27.74 € 918,927 26.74 € 7.2y Granted 0 0.00 € Exercised 0 0.00 € Forfeited or Expired 0 0.00 € Balance as of December 31, 201 9 852,260 35.35 € 918,927 35.12 € 6.9y
Summary of assumptions Weighted-average Fair Values of Warrants Granted and Assumptions Used for Black-Scholes Option Pricing Model	The weighted-average fair values of warrants granted and the assumptions used for the Black-Scholes option pricing model were as follows: 2016 2017 Weighted-Average fair values of warrants granted 9.33€ 13.20€ Assumptions: Risk-free interest rate 0.00% - 0.04% 0.12% Share entitlement per options 1 1 Exercise price 18.68€ - 27.37€ 24.34€ Grant date share fair value 16.42€ - 22.48€ 24.95€ Expected volatility 62.8% - 63.1% 64.7% Expected term (in years) 6.00 6.00 Vesting conditions Service Service Vesting period Graded Graded
S A free shares [member]
Statement [Line Items]
Summary of Number of Shares Outstanding and Weighted Average Grant Date Fair Value	Information on free shares activity follows: Number of Free Weighted- Unvested balance at December 31, 2017 15,600 28.17 € Granted 56,000 17.37 € Vested 0 0.00 € Cancelled 0 0.00 € Unvested balance at December 31, 2018 71,600 27.37 € Granted 57,000 13.04 € Vested (35,600 ) 25.74 € Cancelled (26,000 ) 21.65 € Unvested balance at December 31, 2019 67,000 13.98 €
Stock options [member]
Statement [Line Items]
Summary of Information on Stock Option Activity	Information on stock option activity follows: Options Weighted- Options Weighted- Remaining Balance as of December 31, 201 7 3,822,772 28.02 € 9,332,604 25.17 € 8.3y Granted 140,000 22.96 € Exercised (319,568 ) 19.72 € Forfeited or Expired (174,930 ) 23.68 € Balance as of December 31, 201 8 5,644,044 27.47 € 8,978,106 25.36 € 7.3y Granted 1,650,800 17.90 € Exercised — — Forfeited or Expired (956,524 ) 24.01 € Balance as of December 31, 201 9 6,922,172 26.30 € 9,672,382 24.22 € 6.8y
Summary of assumptions Vesting Details	The weighted-average fair values of stock options granted and the assumptions used for the Black-Scholes option pricing model were as follows: 201 7 201 8 201 9 Weighted-Average fair values of stock options granted 14.30 8.84€ 10.19€ Assumptions: Risk-free interest rate 0.03% 0.13% - 0.21% -0.38% - 0.09% Share entitlement per options 1 1 1 Exercise price 22.57€ 18.37€ - 24.80€ 11.06€ - 18.25€ Grant date share fair value 24.01€ 16€ - 17.78€ 11.32€ - 17.80€ Expected volatility 65.6% 63.3% - 63.4% 60.0% - 66.6% Expected term (in years) 6.12 6.25 5.78 - 6.25 Vesting conditions Service Service Service Vesting period Graded Graded Graded
Stock options [member] | Calyxt Inc. [member]
Statement [Line Items]
Summary of Information on Stock Option Activity	Information on stock option activity follows: Options Weighted- Options Weighted- Remaining Balance as of December 31, 2017 1,244,968 $ 5.20 3,883,432 $ 9.16 8.8y Granted 554,243 $ 16.69 Exercised (592,342 ) $ 4.43 Forfeited or Expired (643,446 ) $ 12.52 Balance as of December 31, 2018 1,278,038 $ 7.45 3,201,887 $ 10.67 8.2y Granted 1,590,000 $ 13.80 Exercised (95,327 ) $ 3.61 Forfeited or Expired (227,696 ) $ 14.68 Other activity 12,495 $ 13.29 Balance as of December 31, 2019 1,789,567 $ 8.73 4,481,359 $ 11.73 6.8y
Summary of assumptions Vesting Details	The estimated fair values of stock options granted and the assumptions used for the Black-Scholes option pricing model were as follows: 2017 2018 2019 Weighted-Average fair values of stock options granted $4.00 $9.09 $10.21 Assumptions: Risk-free interest rate 1.96% 2.45% - 2.89% 1.7% - 2.5% Share entitlement per options 1 1 1 Exercise price $13.29 $14.24 - $23.39 $4.05 - $15.39 Grant date share fair value $13.29 $14.24 - $23.39 $4.05 - $15.39 Expected volatility 25% 40.86% - 57.22% 52.6% - 78.9% Expected term (in years) 6.6 5.6 - 10.0 6.8 - 10.0 Vesting conditions Service Service Service Vesting period Graded Graded Graded
Restricted Stock Unit [Member] | Calyxt Inc. [member]
Statement [Line Items]
Summary of Information on Stock Option Activity	Information on restricted stock unit activity follows: Number of Weighted-Average Unvested balance at December 31, 2017 1,373,933 $ 13.29 Granted 315,825 $ 16.68 Vested (261,507 ) $ 14.07 Cancelled (376,837 ) $ 13.30 Unvested balance at December 31, 2018 1,051,414 $ 14.11 Granted 100,000 $ 12.48 Vested (324,043 ) $ 9.69 Cancelled (13,845 ) $ 12.72 Unvested balance at December 31, 2019 813,526 $ 9.41
Performance Stock Unit [Member] | Calyxt Inc. [member]
Statement [Line Items]
Summary of Information on Stock Option Activity	Information on performance stock unit activity follows: Number of Weighted- Unvested balance at December 31, 2018 $ — $ — Granted 311,667 $ 7.06 Vested $ — $ — Cancelled $ — $ — Unvested balance at December 31, 2019 311,667 $ 7.06
Summary of assumptions Detail Of Stock Unit Activity Performance Stock	The fair value of the performance stock units and the assumptions used for the Monte Carlo simulation were as follows: Date of grant 06/28/2019 Estimated fair values of performance stock units granted $ 7.06 Assumptions: Risk-free interest rate 1.71 % Expected volatility 75.0 % Expected term (in years) 3.0 years

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Earnings per share	Detail of earnings per share For 2017 2018 2019 Net income (loss) attributable to shareholders of Cellectis ($ in thousands) (99,368 ) (78,693 ) (102,091 ) Adjusted weighted average number of outstanding shares, used to calculate both basic and diluted net result per share 35,690,636 40,774,197 42,442,136 Basic / Diluted net income (loss) per share ($ / share) Basic net income (loss) per share ($ /share) (2.78 ) (1.93 ) (2.41 ) Diluted net income (loss) per share ($ /share) (2.78 ) (1.93 ) (2.41 )

Provisions (Tables)

Provisions (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Details of Provisions	Details of provisions 01/01/2018 Additions Amounts used during the period Reversals OCI 12/31/2018 $ in thousands Pension 2,193 314 (54 ) — (175 ) 2,278 Loss on contract 1,876 — (834 ) — 1 1,043 Employee litigation and severance 1 43 — (1 ) (2 ) 41 Commercial litigation 782 646 — (570 ) (8 ) 850 Redundancy plan 7 — — (6 ) (1 ) — Total 4,858 1,003 (888 ) (577 ) (186 ) 4,211 Non-current 3,430 314 (888 ) — (175 ) 2,681 Current provisions 1,427 688 — (577 ) (11 ) 1,528 01/01/2019 Reclassification Additions Amounts used Reversals OCI 12/31/2019 Pension 2,278 — 314 — — 263 2,855 Loss on contract* — 1,043 690 (1,461 ) — — 272 Employee litigation and severance 41 — 715 (43 ) (75 ) 1 639 Commercial litigation 850 — 2,604 (595 ) (17 ) (11 ) 2,832 Total 3,169 1,043 4,323 (2,099 ) (92 ) 253 6,598 Non-current 2,278 314 — — 263 2,855 Current provisions 891 1,043 4,009 (2,099 ) (92 ) (10 ) 3,743
Schedule of Estimation of Retirement Indemnity to Employee	As part of the estimation of the retirement indemnity to employee, the following assumptions were used for all categories of employees: 2017 2018 2019 % social security contributions 45.00 45.00% 45.00% Salary increases 3.50% 3.50% 3.50% Discount rate 1.75% 1.75% 1.00 % Terms of retirement voluntary retirement Retirement age 65 65 65
Summary of Net Defined Benefit Liability and Components	The following table shows reconciliation from the opening balances to the closing balances for net defined benefit liability and its components. $ in thousands As of January 1, 2017 (562 ) Current service cost (925 ) Interest cost (24 ) Actuarial gains and losses (515 ) Reclassification/CTA (168 ) As of December 31, 2017 (2,194 ) Current service cost (276 ) Interest cost (38 ) Benefit paid 54 Actuarial gains and losses 70 Reclassification/CTA 105 As of December 31, 2018 (2,278 ) Current service cost (275 ) Interest cost (39 ) Benefit paid — Actuarial gains and losses (303 ) Reclassification/CTA 40 As of December 31, 2019 (2,855 )

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2019
Text block1 [abstract]
Details of commitments	Details of commitments As of December 31, 2019 Total Less than 1 1 - 3 years 3 - 5 years More than 5 $ in thousands L s 73,181 4,014 18,886 9,764 40,516 License agreements 18,607 1,389 2,778 2,778 11,662 Manufacturing agreements 6,218 6,218 — — — Clinical & R&D agreements 2,086 1,424 662 — — Con struction agreements 39,741 39,741 — Other agreements 50,896 30,851 20,045 — — Total contractual obligations 190,728 83,637 42,371 12,542 52,179

Accounting Principles - Additio

Accounting Principles - Additional Information (Detail)

May 22, 2018USD ($)$ / sharesshares

Jul. 25, 2017USD ($)$ / sharesshares

Dec. 31, 2019USD ($)$ / shares

Dec. 31, 2018USD ($)$ / shares

Dec. 31, 2017USD ($)$ / shares

Dec. 31, 2016USD ($)Subsidiaries$ / shares

Jan. 01, 2019USD ($)

Jan. 01, 2017USD ($)

Disclosure of changes in accounting estimates [line items]

Equity adjustment

$ 355,470,000

[1]

$ 450,272,000

[2]

$ 283,986,000

[2],[3]

$ 272,984,000

[2],[3]

$ 450,272,000

Gross proceeds

$ 57,000,000

$ 64,400,000

Par value per share | $ / shares

$ 0.05

$ 0.05

$ 0.05

$ 0.05

Shares to underwriters

20,000,000

Number of subsidiaries | Subsidiaries

2

Discounting Rate

1.00%

Payment Of Lease Liabilities

[1]

$ 3,393,000

IFRS 16 [Member]

Disclosure of changes in accounting estimates [line items]

Lease Rent

4,000,000

Amortization On Lease

4,600,000

Interest Expense On Lease Liabilities

$ 2,600,000

Paris [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

2.00%

Roseville [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

8.00%

Minnesota [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

8.00%

Raleigh [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

8.00%

North Carolina [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

8.00%

New York [Member]

Disclosure of changes in accounting estimates [line items]

Discounting Rate

4.40%

Top of Range [member] | IFRS 16 [Member]

Disclosure of changes in accounting estimates [line items]

Threshold limit of underlying asset

$ 5,000

Cellectis, Inc. [member]

Disclosure of changes in accounting estimates [line items]

Ownership interest in subsidiary

100.00%

100.00%

Calyxt Inc [member]

Disclosure of changes in accounting estimates [line items]

Ownership interest in subsidiary

68.90%

69.50%

Gross proceeds

$ 57,000,000

$ 64,400,000

$ 58,000,000

Common stock sold | shares

4,057,500

8,050,000

Par value per share | $ / shares

$ 15

$ 8

Shares to underwriters

$ 20,000,000

Selling price per common share | $ / shares

$ 15

Common stock for exercising underwriters' option | shares

457,500

Underwriting discounts and commissions

$ 3,200,000

$ 3,100,000

Offering expense

$ 700,000

Non-controlling shareholders interest

31.10%

30.50%

20.30%

Calyxt Inc [member] | IFRS 16 [Member]

Disclosure of changes in accounting estimates [line items]

Increase in right of used assets

$ 1,800,000

Calyxt Inc [member] | Cellectis [Member]

Disclosure of changes in accounting estimates [line items]

Purchase of common stock | shares

550,000

Purchase of common stock, value

$ 8,300,000

Adjustments [member] | Increase (Decrease) Due to Application of IFRS 15 [member]

Disclosure of changes in accounting estimates [line items]

Equity adjustment

$ 1,700,000

[1]

The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

[2]

Corresponds to the impact of Calyxt stock options exercises during the period.

[3]

Reflects the application of IFRS15 with effect from January 1, 2018 using the full retrospective method.

Accounting Principles - Schedul

Accounting Principles - Schedule Of Information About Lease Assets And Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	[1]	Jan. 01, 2019	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Non-current assets
Intangible assets	$ 1,108		$ 1,268	$ 1,268		$ 1,431		$ 1,343
Property, plant, and equipment	23,712		8,732	10,041		7,226		16,900
Right-of-use assets	45,612		37,569
Other non-current financial assets	5,517		1,891	1,891		300
Total non-current assets	75,949		49,460	13,199
Current assets
Inventories	2,897		275	275
Trade receivables	2,959		2,971	2,971
Subsidies receivables	9,140		17,173	17,173
Other current assets	15,617		13,194	15,333
Current financial assets	20,385		388	388
Cash and cash equivalents	340,522		451,501	451,501	[1]	256,380		254,568
Total current assets	391,520		485,502	487,641
TOTAL ASSETS	467,469		534,961	500,840
Shareholders' equity
Share capital	2,767		2,765	2,765
Premiums related to the share capital	843,478		828,525	828,525
Treasury share reserve
Currency translation adjustment	(22,641)		(16,668)	(16,668)
Retained earnings (deficit)	(406,390)		(326,628)	(326,628)
Net income (loss)	(102,091)		(78,693)	(78,693)
Total shareholders' equity - Group Share	315,123		409,301	409,301
Non-controlling interests	40,347		40,970	40,970
Total shareholders' equity	355,470		450,272	450,272	[2]	$ 283,986	[2],[3]	$ 272,984	[2],[3]
Non-current liabilities
Non-current lease debts	46,540		32,737	1,018
Non-current provisions	2,855		2,042	2,681
Total non-current liabilities	49,395		34,779	3,699
Current liabilities
Current lease debts	1,067		4,076	333
Trade payables	29,264		15,883	15,883
Deferred revenues and contract liabilities	20,033		20,454	20,754
Current provisions	3,743		1,127	1,530
Other current liabilities	8,497		8,369	8,369
Total current liabilities	62,604		49,910	46,869
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 467,469		534,961	$ 500,840
Previously stated [member]
Non-current assets
Intangible assets			1,268
Property, plant, and equipment			10,041
Other non-current financial assets			1,891
Total non-current assets			13,199
Current assets
Inventories			275
Trade receivables			2,971
Subsidies receivables			17,173
Other current assets			15,333
Current financial assets			388
Cash and cash equivalents			451,501
Total current assets			487,641
TOTAL ASSETS			500,840
Shareholders' equity
Share capital			2,765
Premiums related to the share capital			828,525
Treasury share reserve
Currency translation adjustment			(16,668)
Retained earnings (deficit)			(326,628)
Net income (loss)			(78,693)
Total shareholders' equity - Group Share			409,301
Non-controlling interests			40,970
Total shareholders' equity			450,272
Non-current liabilities
Non-current lease debts			1,018
Non-current provisions			2,681
Total non-current liabilities			3,699
Current liabilities
Current lease debts			333
Trade payables			15,883
Deferred revenues and contract liabilities			20,754
Current provisions			1,530
Other current liabilities			8,369
Total current liabilities			46,869
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY			500,840
Increase Decrease Due To Application Of IFRS 16 [Member]
Non-current assets
Property, plant, and equipment			(1,309)
Right-of-use assets			37,569
Total non-current assets			36,260
Current assets
Other current assets			(2,139)
Total current assets			(2,139)
TOTAL ASSETS			34,121
Non-current liabilities
Non-current lease debts			31,720
Non-current provisions			(639)
Total non-current liabilities			31,081
Current liabilities
Current lease debts			3,743
Deferred revenues and contract liabilities			(299)
Current provisions			(403)
Total current liabilities			3,041
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY			$ 34,121
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.
[2]	Corresponds to the impact of Calyxt stock options exercises during the period.
[3]	Reflects the application of IFRS15 with effect from January 1, 2018 using the full retrospective method.

Accounting Principles - Summary

Accounting Principles - Summary of Operating lease commitments disclosed under IAS 17 (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Schedule Of Operating Lease Commitments Under IAS17 [Abstract]
Sale and lease-back agreement	$ 31,668
Facility lease agreements	28,230
Total	59,898
-Discounting impact & assumption changes	(18,966)
-Facility lease termination	(4,220)
-Other	101
Total lease debt	$ 1,018	$ 46,540

Information Concerning the Gr_3

Information Concerning the Group's Consolidated Operations - Revenues by Country of Origin and Other Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disclosure of revenue [line items]
Revenues	$ 15,190	[1]	$ 12,731	$ 25,188
Research tax credit	7,800		8,561	8,327
Subsidies and other			140	201
Other income	7,800	[1]	8,701	8,528
Total revenues and other income	22,990	[1]	21,432	33,715
France [member]
Disclosure of revenue [line items]
Revenues	7,896		12,495	24,680
United States [member]
Disclosure of revenue [line items]
Revenues	$ 7,294		$ 236	$ 508
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Information Concerning the Gr_4

Information Concerning the Group's Consolidated Operations - Revenues by Nature (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disclosure of revenue [line items]
Recognition of previously deferred upfront payments			$ 7,114	$ 14,875
Other revenues	$ 6,055		3,383	7,945
Collaboration agreements	6,055		10,497	22,821
Licenses	1,762		2,142	2,270
Products & services	7,373		92	97
Total revenues	$ 15,190	[1]	$ 12,731	$ 25,188
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Information Concerning the Gr_5

Information Concerning the Group's Consolidated Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2014Agreement
Consolidated operations [line items]
Number of collaboration agreements | Agreement				2
Decrease (increase) in financial income and expenses	$ 8,400,000	$ (27,800,000)
Decrease (increase) in net foreign exchange gain	6,700,000	(27,000,000)
Decrease (increase) in interest income and expenses	2,600,000	(4,800,000)
Decrease (increase) in foreign exchange derivatives fair value adjustment	600,000	4,000,000
Other immaterial variances	100,000
Credits and net operating loss carryforwards	$ (102,112,000)	(65,555,000)	$ (51,640,000)
Carryforwards limit that can be offset against future taxable profit, additional percentage of profit exceeding the limit	50.00%
Products & services	$ 7,373,000	92,000	97,000
Increase decrease others	200,000
ALLO715 [Member]
Consolidated operations [line items]
Revenue from performance obligation	5,000,000
Top of Range [member]
Consolidated operations [line items]
Carryforwards limit that can be offset against future taxable profit	1,000,000
France [member]
Consolidated operations [line items]
Credits and net operating loss carryforwards	(246,000,000)	(186,000,000)	(144,000,000)
United States [member]
Consolidated operations [line items]
Credits and net operating loss carryforwards	162,000,000	86,000,000	62,000,000
Calyxt Inc [member]
Consolidated operations [line items]
Revenues from technology licenses	$ 300,000	$ 300,000	$ 500,000
Client A [member]
Consolidated operations [line items]
Percentage of Revenue	36.00%	55.00%	11.00%
Client B [member]
Consolidated operations [line items]
Percentage of Revenue	28.00%	21.00%	69.00%
Calyxt [Member] | High Oleic Soyabean Meal [Member]
Consolidated operations [line items]
Revenue from sale of food	$ 5,600,000
Calyxt [Member] | High Oleic Soyabean Oil [Member]
Consolidated operations [line items]
Products & services	1,700,000
Calyxt [Member] | United States [member] | Indefinite Carry Forward [Member]
Consolidated operations [line items]
Credits and net operating loss carryforwards	64,000,000
Calyxt [Member] | United States [member] | 2019 [Member]
Consolidated operations [line items]
Credits and net operating loss carryforwards	0
Calyxt [Member] | United States [member] | 2032 and beyond [Member]
Consolidated operations [line items]
Credits and net operating loss carryforwards	$ 41,900,000

Information Concerning the Gr_6

Information Concerning the Group's Consolidated Operations - Details of Operating Expenses by Nature (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Expense by nature [line Items]
Total research and development expenses	$ (92,042)	[1]	$ (76,567)	$ (79,227)
Total selling, general and administrative expenses	(43,017)	[1]	(47,248)	(44,750)
Cost of revenue	(11,392)	[1]	(2,739)	(2,620)
Research and Development Expenses [member]
Expense by nature [line Items]
Royalty expenses	(2,112)		(2,739)	(2,620)
Wages and salaries	(21,294)		(16,452)	(12,986)
Social charges on free shares and stock option grants	(1,357)		(99)	(1,088)
Non-cash stock based compensation expense	(12,260)		(18,057)	(23,832)
Personnel expenses	(34,911)		(34,608)	(37,906)
Purchases and external expenses	(49,251)		(40,458)	(38,458)
Other	(7,880)		(1,501)	(2,863)
Cost of good sold	(9,280)
Cost of revenue	(11,392)		(2,739)	(2,620)
Personnel Expenses [member]
Expense by nature [line Items]
Wages and salaries	(34,116)		(27,825)	(20,005)
Social charges on free shares and stock option grants	(1,848)		(128)	(1,969)
Non-cash stock based compensation expense	(26,881)		(37,218)	(50,418)
Personnel expenses	(62,845)		(65,171)	(72,392)
Selling, General and Administrative Expenses [member]
Expense by nature [line Items]
Wages and salaries	(12,822)		(11,373)	(7,019)
Social charges on free shares and stock option grants	(491)		(29)	(881)
Non-cash stock based compensation expense	(14,621)		(19,161)	(26,586)
Personnel expenses	(27,934)		(30,563)	(34,486)
Purchases and external expenses	(11,431)		(14,251)	(9,138)
Other	$ (3,652)		$ (2,433)	$ (1,126)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Information Concerning the Gr_7

Information Concerning the Group's Consolidated Operations - Details of Financial Income and Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Finance income expense [abstract]
Interest income	$ 6,985		$ 6,787	$ 1,974
Foreign exchange gain	4,481		13,597	1,185
Other financial revenues	505		188	4,102
Total financial revenues	11,971	[1]	20,572	7,262
Interest expenses	(3)		(39)	0
Interest expenses for leases	(2,603)		(7)	(4)
Foreign exchange loss	(671)		(3,090)	(17,734)
Other financial expenses	(354)		(677)	(556)
Total financial expenses	(3,631)	[1]	(3,813)	(18,294)
Total	$ 8,340	[1]	$ 16,758	$ (11,032)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Information Concerning the Gr_8

Information Concerning the Group's Consolidated Operations - Disclosure of Income Tax (Expense or Income) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Major components of tax expense (income) [abstract]
Income (loss) before taxes from continuing operations	$ (115,212)	$ (88,333)	$ (103,683)
Theoretical group tax rate	25.35%	23.66%	34.43%
Theoretical tax benefit (expense)	$ 29,208	$ 20,901	$ 35,698
Permanent differences	(1,131)	832	293
Research tax credit	2,786	2,079	2,926
Share-based compensation & other IFRS adjustments	(7,828)	(8,065)	(8,297)
Non recognition of deferred tax assets related to tax losses and temporary differences	(23,079)	(15,652)	(30,713)
Other differences	43	(95)	92
Effective tax expense	$ 0
Effective tax rate	0.00%	0.00%	0.00%

Information Concerning the Gr_9

Information Concerning the Group's Consolidated Operations - Disclosure of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in deferred tax liability (asset) [abstract]
Credits and net operating loss carryforwards	$ 102,112	$ 65,555	$ 51,640
Pension commitments	714	569	548
Leases	47	(4)	(12)
Impairment of assets	1	10	10
Revenue recognition	197	200
Other	284	491	604
Total unrecognized deferred tax assets, net	$ (103,354)	$ (66,823)	$ (52,790)

Information Concerning the G_10

Information Concerning the Group's Consolidated Operations - Summary of Key Performance Indicators by Reportable Segments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disclosure of operating segments [line items]
External revenues	$ 15,190	[1]	$ 12,731	$ 25,188
External other income	7,800	[1]	8,701	8,528
External revenues and other income	22,990	[1]	21,432	33,715
Cost of revenue	(11,392)	[1]	(2,739)	(2,620)
Research and development expenses	(92,042)	[1]	(76,567)	(79,227)
Selling, general and administrative expenses	(43,017)	[1]	(47,248)	(44,750)
Other operating income and expenses	(91)		31	232
Total operating expenses	(146,542)	[1]	(126,523)	(126,366)
Operating income (loss) before tax	(123,552)	[1]	(105,091)	(92,650)
Financial gain (loss)	8,340	[1]	16,758	(11,032)
Income (loss) from continuing operations	(115,212)		(88,333)	(103,683)
Non controlling interests	(13,121)	[1]	(9,640)	(4,315)
Net income (loss) attributable to shareholders of Cellectis	(102,091)	[1]	(78,693)	(99,368)
Adjustment of share-based compensation attributable to shareholders of Cellectis	23,242		34,563	48,925
Adjusted net income (loss) attributable to shareholders of Cellectis	(78,849)		(44,130)	(50,442)
Depreciation and amortization	(6,875)		(2,377)	(3,371)
Additions to tangible and intangible assets	17,666		4,911	2,642
Research and Development [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	11,629		17,689	23,590
Selling, General and Administration [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	11,613		16,873	25,335
Plants [member]
Disclosure of operating segments [line items]
External revenues and other income	7,294		414	747
Cost of revenue	(9,275)		(595)	(390)
Research and development expenses	(12,390)		(8,638)	(6,057)
Selling, general and administrative expenses	(26,090)		(21,067)	(13,143)
Other operating income and expenses	25		(50)	6
Total operating expenses	(47,730)		(30,351)	(19,584)
Operating income (loss) before tax	(40,436)		(29,937)	(18,837)
Financial gain (loss)	294		1,420	0
Income (loss) from continuing operations	(40,142)		(28,517)	(18,837)
Non controlling interests	(13,121)		(9,640)	(4,315)
Net income (loss) attributable to shareholders of Cellectis	(27,021)		(18,877)	(14,522)
Adjustment of share-based compensation attributable to shareholders of Cellectis	8,292		6,056	5,957
Adjusted net income (loss) attributable to shareholders of Cellectis	(18,729)		(12,821)	(8,565)
Depreciation and amortization	(1,233)		(637)	(551)
Additions to tangible and intangible assets	2,998		1,871	792
Plants [member] | Research and Development [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	1,619		838	967
Plants [member] | Selling, General and Administration [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	6,673		5,218	4,990
Therapeutics [member]
Disclosure of operating segments [line items]
External revenues and other income	15,696		21,018	32,969
Cost of revenue	(2,117)		(2,144)	(2,230)
Research and development expenses	(79,652)		(67,929)	(73,170)
Selling, general and administrative expenses	(16,927)		(26,180)	(31,607)
Other operating income and expenses	(116)		81	225
Total operating expenses	(98,812)		(96,172)	(106,782)
Operating income (loss) before tax	(83,116)		(75,154)	(73,813)
Financial gain (loss)	8,045		15,339	(11,032)
Income (loss) from continuing operations	(75,071)		(59,816)	(84,846)
Non controlling interests	0		0	0
Net income (loss) attributable to shareholders of Cellectis	(75,071)		(59,816)	(84,846)
Adjustment of share-based compensation attributable to shareholders of Cellectis	14,950		28,507	42,968
Adjusted net income (loss) attributable to shareholders of Cellectis	(60,121)		(31,309)	(41,877)
Depreciation and amortization	(5,642)		(1,740)	(2,820)
Additions to tangible and intangible assets	14,668		3,040	1,849
Therapeutics [member] | Research and Development [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	10,010		16,852	22,623
Therapeutics [member] | Selling, General and Administration [member]
Disclosure of operating segments [line items]
Adjustment of share-based compensation attributable to shareholders of Cellectis	4,940		11,655	20,345
Operating Segments [member]
Disclosure of operating segments [line items]
External revenues	15,190		12,731	25,188
Operating Segments [member] | Plants [member]
Disclosure of operating segments [line items]
External revenues	7,294		236	508
Operating Segments [member] | Therapeutics [member]
Disclosure of operating segments [line items]
External revenues	7,896		12,495	24,680
Inter-segment Revenues [member]
Disclosure of operating segments [line items]
External other income	7,800		8,701	8,528
Inter-segment Revenues [member] | Plants [member]
Disclosure of operating segments [line items]
External other income	0		178	239
Inter-segment Revenues [member] | Therapeutics [member]
Disclosure of operating segments [line items]
External other income	7,800		$ 8,523	8,290
Assets Under Construction [member]
Disclosure of operating segments [line items]
Impairment of tangible assets	0			(798)
Assets Under Construction [member] | Plants [member]
Disclosure of operating segments [line items]
Impairment of tangible assets	0
Assets Under Construction [member] | Therapeutics [member]
Disclosure of operating segments [line items]
Impairment of tangible assets	$ 0			$ (798)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Impairment Tests - Additional I

Impairment Tests - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of assets	$ 0	$ 0	$ 0
New Jersey [member] | Discontinue Lease Facility [member]
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment of assets			$ 800,000

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019
Computer Software [member] | Bottom of Range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives	1 year
Computer Software [member] | Top of Range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives	3 years
Patents [member] | Top of Range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives	20 years

Intangible Assets - Details Inf

Intangible Assets - Details Information About Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about intangible assets [line items]
Beginning balance	$ 1,268		$ 1,431	$ 1,343
Change in scope	0
Additions to intangible assets	82		117	141
Disposal of intangible assets	(50)		(7)
Reclassification	6		6
Depreciation expense	(174)		(217)	(231)
Translation adjustments	(24)		(61)	178
Ending balance	1,108	[1]	1,268	1,431
Gross value at end of period	3,125		3,146	3,190
Accumulated depreciation and impairment at end of period	(2,017)		(1,878)	(1,759)
Software and Patents [member]
Disclosure of detailed information about intangible assets [line items]
Beginning balance	577		811	924
Change in scope	0
Additions to intangible assets	84		14	6
Disposal of intangible assets	(50)		(7)
Reclassification	6		6
Depreciation expense	(174)		(217)	(231)
Translation adjustments	(12)		(30)	112
Ending balance	431		577	811
Gross value at end of period	2,448		2,454	2,571
Accumulated depreciation and impairment at end of period	(2,017)		(1,878)	(1,759)
Assets Under Construction [member]
Disclosure of detailed information about intangible assets [line items]
Beginning balance	691		619	419
Change in scope	0
Additions to intangible assets	(2)		103	135
Disposal of intangible assets	0
Reclassification	0
Depreciation expense	0
Translation adjustments	(12)		(31)	66
Ending balance	677		691	619
Gross value at end of period	677		$ 691	$ 517
Accumulated depreciation and impairment at end of period	$ 0
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Right-of-use Assets - Additiona

Right-of-use Assets - Additional Information (Detail) $ in Millions	Dec. 31, 2019USD ($)
Calyxt [Member]
Disclosure of quantitative information about right-of-use assets [line items]
Right of use assets adjusted to net deferred losses	$ 1.8

Right-of-use Assets - Details I

Right-of-use Assets - Details Information About Breakdown Of Right Of Use Assets (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Disclosure of quantitative information about right-of-use assets [line items]
Ending balance	$ 45,612	[1]
Right-of-use assets [member]
Disclosure of quantitative information about right-of-use assets [line items]
Beginning balance	37,569
Additions	12,873
Depreciation expense	(4,578)
Translation adjustments	(252)
Ending balance	45,612
Gross value at end of period	50,328
Accumulated depreciation at end of period	(4,716)
Building lease [member] | Right-of-use assets [member]
Disclosure of quantitative information about right-of-use assets [line items]
Beginning balance	36,061
Additions	11,357
Depreciation expense	(4,058)
Translation adjustments	(248)
Ending balance	43,112
Gross value at end of period	47,175
Accumulated depreciation at end of period	(4,063)
Office and laboratory equipment [member] | Right-of-use assets [member]
Disclosure of quantitative information about right-of-use assets [line items]
Beginning balance	1,508
Additions	1,516
Depreciation expense	(520)
Translation adjustments	(4)
Ending balance	2,500
Gross value at end of period	3,153
Accumulated depreciation at end of period	$ (653)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property Plant and Equipment Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2019
Buildings and Other Outside Improvements [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	10-20 years
Leasehold Improvements [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	5-10 years
Office Furniture [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	10 years
Laboratory Equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	3-10 years
Office Equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	5 years
IT Equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	3 years

Property, Plant and Equipment_2

Property, Plant and Equipment - Disclosure of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	$ 10,041		$ 7,226	$ 16,900
Additions to tangible assets	17,584		6,263	2,501
Disposal of tangible assets	(430)		(1,164)	(9,453)
Reclassification	(5)		(6)
Depreciation expense	(2,123)		(2,091)	(3,140)
Translation adjustments	(46)		(188)	418
Ending balance	23,712	[1]	10,041	7,226
Gross value at end of period	41,529		26,160	22,103
Accumulated depreciation and impairment at end of period	(17,817)		(16,119)	(14,877)
IFRS 16 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	8,732
Ending balance			8,732
Land and Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	3,229		3,159	12,436
Additions to tangible assets	318		879	718
Disposal of tangible assets				(9,243)
Reclassification	15		39	14
Depreciation expense	(192)		(758)	(972)
Translation adjustments	(40)		(90)	206
Ending balance	3,330		3,229	3,159
Gross value at end of period	7,833		7,604	6,936
Accumulated depreciation and impairment at end of period	(4,503)		(4,375)	(3,777)
Land and Buildings [member] | IFRS 16 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	3,229
Ending balance			3,229
Technical Equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	3,393		2,505	2,858
Additions to tangible assets	374		1,622	701
Disposal of tangible assets	(10)		(49)	(103)
Reclassification	1,974		216	47
Depreciation expense	(1,247)		(854)	(1,126)
Translation adjustments	(15)		(46)	127
Ending balance	3,160		3,393	2,505
Gross value at end of period	13,962		13,297	12,114
Accumulated depreciation and impairment at end of period	(10,802)		(9,903)	(9,609)
Technical Equipment [member] | IFRS 16 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	2,084
Ending balance			2,084
Fixtures, Fittings and Other Equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	2,172		753	707
Additions to tangible assets	329		1,820	203
Disposal of tangible assets	(1)		(690)	2
Reclassification	630		793	18
Depreciation expense	(684)		(478)	(245)
Translation adjustments	(11)		(27)	68
Ending balance	2,435		2,172	753
Gross value at end of period	4,149		3,215	1,447
Accumulated depreciation and impairment at end of period	(1,714)		(1,043)	(693)
Fixtures, Fittings and Other Equipment [member] | IFRS 16 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	2,172
Ending balance			2,172
Assets Under Construction [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	1,247		809	898
Additions to tangible assets	16,563		1,942	878
Disposal of tangible assets	(419)		(426)	(109)
Reclassification	(2,624)		(1,053)	(79)
Depreciation expense				(798)
Translation adjustments	20		(25)	18
Ending balance	14,787		1,247	809
Gross value at end of period	15,585		2,045	1,606
Accumulated depreciation and impairment at end of period	(798)		(798)	$ (798)
Assets Under Construction [member] | IFRS 16 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	$ 1,247
Ending balance			$ 1,247
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Property, Plant and Equipment_3

Property, Plant and Equipment - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019EUR (€)
Disclosure of detailed information about property, plant and equipment [line items]
Assets pledged as security for financial liabilities | €				€ 0
Additions to tangible assets	$ 17,584	$ 6,263	$ 2,501
IAS 17 [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Net deferred losses recognised	1,800
Assets Under Construction [member]
Disclosure of detailed information about property, plant and equipment [line items]
Additions to tangible assets	16,563	$ 1,942	878
Assets Under Construction [member] | Paris [member]
Disclosure of detailed information about property, plant and equipment [line items]
Additions to tangible assets	4,900
Assets Under Construction [member] | North Carolina [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Additions to tangible assets	8,800
Calyxt Inc and Cellectis BioResearch Inc [member]
Disclosure of detailed information about property, plant and equipment [line items]
Additions to tangible assets	300
Other equipment	$ 700
Calyxt Inc. [member]
Disclosure of detailed information about property, plant and equipment [line items]
Net book value of assets sold			$ 9,200

Financial Assets and Liabilit_3

Financial Assets and Liabilities - Summary of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	$ 340,522	$ 451,508
Accounting category amortized cost	38,001	22,416
Book value on the statement of financial position	378,523	473,924
Fair value	378,523	473,924
Accounting category fair value through profit and loss	0	0
Accounting category amortized cost	85,368	25,603
Book value on the statement of financial position	85,368	25,603
Fair value	85,368	25,603
Non-Current Financial Assets [member]
Disclosure of financial assets and liabilities [line items]
Accounting category amortized cost	5,517	1,891
Book value on the statement of financial position	5,517	1,891
Fair value	5,517	1,891
Trade Receivables [member]
Disclosure of financial assets and liabilities [line items]
Accounting category amortized cost	2,959	2,971
Book value on the statement of financial position	2,959	2,971
Fair value	2,959	2,971
Subsidies Receivables [member]
Disclosure of financial assets and liabilities [line items]
Accounting category amortized cost	9,140	17,173
Book value on the statement of financial position	9,140	17,173
Fair value	9,140	17,173
Current Financial Assets [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss		7
Accounting category amortized cost	20,385	381
Book value on the statement of financial position	20,385	388
Fair value	20,385	388
Cash and Cash Equivalents [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	340,522	451,501
Book value on the statement of financial position	340,522	451,501
Fair value	340,522	451,501
Non-Current Financial Liabilities [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	0	0
Accounting category amortized cost	46,540	1,018
Book value on the statement of financial position	46,540	1,018
Fair value	46,540	1,018
Current Financial Liabilities [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	0	0
Accounting category amortized cost	1,067	333
Book value on the statement of financial position	1,067	333
Fair value	1,067	333
Trade Payables [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	0	0
Accounting category amortized cost	29,264	15,883
Book value on the statement of financial position	29,264	15,883
Fair value	29,264	15,883
Other Current Liabilities1 [member]
Disclosure of financial assets and liabilities [line items]
Accounting category fair value through profit and loss	0	0
Accounting category amortized cost	8,497	8,369
Book value on the statement of financial position	8,497	8,369
Fair value	$ 8,497	$ 8,369

Financial Assets and Liabilit_4

Financial Assets and Liabilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Jan. 01, 2019	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets and liabilities [line items]
Derivative financial assets	$ 0
Finance lease liabilities	47,600,000
Cash and cash equivalents	$ 340,522,000	[1]	$ 451,501,000	[1]	$ 451,501,000	$ 256,380,000	$ 254,568,000
US Dollar [member] | Cash Cash and Cash Equivalents and Current Assets [member]
Disclosure of financial assets and liabilities [line items]
Currency denominated percentage	63.00%		66.00%
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Jan. 01, 2019
Disclosure of inventories [line items]
Inventories	$ 2,897	[1]	$ 275	$ 275
Provision for impairment	0		0
Grain And Seeds [Member] | Calyxt Inc [Member]
Disclosure of inventories [line items]
Inventories	2,600
Laboratory Equipment [member]
Disclosure of inventories [line items]
Inventories	$ 300		$ 300
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Trade Receivables and Other C_3

Trade Receivables and Other Current Assets - Disclosure of Trade Receivables (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Trade and other receivables [abstract]
Trade receivables	$ 3,513	$ 3,353
Valuation allowance	(554)	(382)
Total net value of trade receivables	$ 2,959	$ 2,971

Trade Receivables and Other C_4

Trade Receivables and Other Current Assets - Disclosure of Subsidies Receivables (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Receivables1 [abstract]
Research tax credit	$ 9,140	$ 16,842	$ 7,400
Other subsidies		1,598
Valuation allowance for other subsidies		(1,266)
Total subsidies receivables	$ 9,140	$ 17,173

Trade Receivables and Other C_5

Trade Receivables and Other Current Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2017
Prepaid expenses and other current assets [line items]
Research tax credit receivables	$ 16,842	$ 9,140			$ 7,400
Other current assets	15,333	15,617	[1]	$ 13,194
Social charges on personnel expenses	200
Right-of-use assets [member]
Prepaid expenses and other current assets [line items]
Deferred expense on sale and lease-back transaction				$ 2,100
Calyxt Inc. [member]
Prepaid expenses and other current assets [line items]
Deferred expense on sale and lease-back transaction	2,100
Other current assets	300
France [member]
Prepaid expenses and other current assets [line items]
Research tax credit receivables	$ 7,800	$ 7,900			$ 8,000
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Trade Receivables and Other C_6

Trade Receivables and Other Current Assets - Disclosure of Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Other Current Assets [abstract]
VAT receivables	$ 3,044			$ 1,679
Prepaid expenses and other prepayments	11,829			10,985
Tax and social receivables	150			244
Deferred expenses and other current assets	594			2,425
Total other current assets	$ 15,617	[1]	$ 13,194	$ 15,333
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Current Financial Assets and _3

Current Financial Assets and Cash and Cash Equivalents - Summary of Current Financial Assets and Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Disclosure of current financial assets and cash and cash equivalents [line items]
Current financial assets	$ 20,385	[1]	$ 388	$ 388
Cash and cash equivalents	340,522	[1]	$ 451,501	451,501	[1]	$ 256,380	$ 254,568
Carrying Value [member]
Disclosure of current financial assets and cash and cash equivalents [line items]
Current financial assets	20,385			388
Cash and cash equivalents	340,522			451,501
Current financial assets and cash and cash equivalents	360,907			451,889
Estimated Fair Value [member]
Disclosure of current financial assets and cash and cash equivalents [line items]
Current financial assets	20,385			388
Cash and cash equivalents	340,522			451,501
Current financial assets and cash and cash equivalents	$ 360,907			$ 451,889
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Current Financial Assets and _4

Current Financial Assets and Cash and Cash Equivalents - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Disclosure of current financial assets and cash and cash equivalents [line items]
Other current financial assets	$ 0	$ 0
Furniture and equipment sales lease back [member]
Disclosure of current financial assets and cash and cash equivalents [line items]
Restricted cash	1,500,000	1,500,000
Short term restricted cash	400,000	$ 400,000
Manufacturing Facility [Member]
Disclosure of current financial assets and cash and cash equivalents [line items]
Short term restricted cash	$ 20,000,000

Current Financial Assets and _5

Current Financial Assets and Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents [abstract]
Cash and bank accounts	$ 270,630			$ 398,178
Money market funds	13,722			13,248
Fixed bank deposits	56,170			40,075
Total cash and cash equivalents	$ 340,522	[1]	$ 451,501	$ 451,501	[1]	$ 256,380	$ 254,568
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Financial Liabilities - Schedul

Financial Liabilities - Schedule of Financial Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Categories of financial liabilities [abstract]
Lease debts / Finance lease	$ 46,540	[1]	$ 32,737	$ 1,018
Total non-current financial liabilities	46,540			1,018
Lease debts / Finance lease	1,067	[1]	$ 4,076	333
Total current financial liabilities	1,067			333
Trade payables	29,264			15,883
Other current liabilities	8,497			8,369
Total Financial liabilities	$ 85,368			$ 25,603
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Financial Liabilities - Sched_2

Financial Liabilities - Schedule Representing Due Dates of the Financial Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Disclosure of offsetting of financial liabilities [line items]
Lease debts	$ 47,600
Financial liabilities	47,607
Trade payables	29,264	$ 15,883
Other current liabilities	8,497	8,369
Total Financial liabilities	85,368	$ 25,603
Less than One Year [member]
Disclosure of offsetting of financial liabilities [line items]
Lease debts	1,067
Financial liabilities	1,067
Trade payables	29,264
Other current liabilities	8,497
Total Financial liabilities	38,828
One to Five Years [member]
Disclosure of offsetting of financial liabilities [line items]
Lease debts	46,540
Financial liabilities	46,540
Total Financial liabilities	$ 46,540

Other Current Liabilities - Sum

Other Current Liabilities - Summary of Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Miscellaneous current liabilities [abstract]
VAT Payables	$ 130			$ 291
Accruals for personnel related expenses	7,295			7,041
Other	1,072			1,037
Total	$ 8,497	[1]	$ 8,369	$ 8,369
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Other Current Liabilities - Add

Other Current Liabilities - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Other current liabilities [abstract]
Board of directors attendance fee	$ 0.3	$ 0.3
Liabilities	0.2	$ 0.3
Accrued liabilitites current for fixed assets	$ 0.6

Deferred Revenues and Contrac_3

Deferred Revenues and Contract Liabilities - Summary of Deferred Revenues and Contract Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accruals and deferred income [abstract]
Deferred revenues and contract liabilities	$ 20,033	$ 20,454
Others		299
Total Deferred revenue and contract liabilities	$ 20,033	$ 20,754

Capital - Schedule of Classes o

Capital - Schedule of Classes of Share Capital (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Disclosure of classes of share capital [line items]
Beginning balance	[1]	$ 450,272		$ 283,986	[2]	$ 272,984	[2]
Balance at beginning of year		42,430,069		35,960,062		35,335,060
Capital increase by issuance of common shares		35,600		6,146,000		466,950
Exercise of share warrants, employee warrants and stock options				324,007		158,052
Other movements				$ (40)		$ (38)
Balance at end of year		$ 355,470	[3]	$ 450,272	[1]	$ 283,986	[1],[2]
Balance at end of year		42,465,669		42,430,069		35,960,062
Nominal value		$ 0.05		$ 0.05		$ 0.05
Nominal value		$ 0.05		$ 0.05		$ 0.05
Reserve of Share-based Payments [member]
Disclosure of classes of share capital [line items]
Non-cash stock based compensation expense		$ 14,951		$ 28,507		$ 42,968
Premiums Related to Share Capital [member]
Disclosure of classes of share capital [line items]
Beginning balance	[1]	828,525		614,037	[2]	568,185	[2]
Capital increase by issuance of common shares				178,230
Exercise of share warrants, employee warrants and stock options				7,751		2,921
Other movements		2				(37)
Balance at end of year		843,478		828,525	[1]	614,037	[1],[2]
Share Capital Ordinary Shares [member]
Disclosure of classes of share capital [line items]
Beginning balance	[1]	2,765		2,367	[2]	2,332	[2]
Capital Increase		2		379		26
Exercise of share warrants, employee warrants and stock options				19		9
Other movements		0
Balance at end of year		$ 2,767		$ 2,765	[1]	$ 2,367	[1],[2]
[1]	Corresponds to the impact of Calyxt stock options exercises during the period.
[2]	Reflects the application of IFRS15 with effect from January 1, 2018 using the full retrospective method.
[3]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Capital - Additional Informatio

Capital - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	May 22, 2018	Jul. 25, 2017	Oct. 28, 2014	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Dec. 31, 2016	Oct. 28, 2011
Capital structure [line items]
Exercise stock option	$ 57,000	$ 64,400
Voting right description				At December 31, 2019, we had 42,465,669 ordinary shares outstanding of which 4,389,581 had a double voting right.		At December 31, 2018, we had 42,430,069 ordinary shares outstanding of which 5,016,911 had a double voting right.	At December 31, 2017, we had 35,960,062 ordinary shares outstanding of which 5,155,335 had a double voting right
Number of shares ordinary outstanding				42,465,669		42,430,069	35,960,062		35,335,060
Number of shares ordinary having double voting right				4,389,581		5,016,911	5,155,335
Par value per share				$ 0.05		$ 0.05	$ 0.05		$ 0.05
Shares to underwriters		$ 20,000
Other non-current financial assets				$ 5,517	[1]	$ 1,891	$ 300	$ 1,891
BSA [member]
Capital structure [line items]
Ordinary shares issued			1,470,836							12,195,113
Hold Two Years [member]
Capital structure [line items]
Voting right description				After a shareholder continuously holds ordinary shares for two years, each ordinary share held by such shareholder is entitled to two votes.
Calyxt Inc [member]
Capital structure [line items]
Ordinary shares issued	4,057,500	8,050,000
Exercise stock option	$ 57,000	$ 64,400					58,000
Underwriting discounts and commissions	$ 3,200						$ 3,100
Par value per share	$ 15	$ 8
Shares to underwriters		$ 20,000
Non-controlling shareholders interest				31.10%		30.50%	20.30%
Offering expense	$ 700
BSA [member]
Capital structure [line items]
Exercise stock option			$ 16,400
Calyxt Inc. [member]
Capital structure [line items]
Ordinary shares issued	4,057,500	8,050,000
Equity interests				6.10%		3.10%	9.80%
Compensation expense				$ 4,400		$ 3,300	$ 5,200
Calyxt Inc. [member] | Cellectis [member]
Capital structure [line items]
Purchase of common stock	550,000
Purchase of common stock, value	$ 8,300
Natixis [member] | Treasury Shares [member]
Capital structure [line items]
Initial advance payment on liquidity contract							$ 400
Capital revolution 2017 [member]
Capital structure [line items]
Ordinary shares issued							31,873
Options exercise							31,873
Exercise stock option							$ 734,234
Capital revolution 2017 [member] | BSA [member]
Capital structure [line items]
Exercise stock option							$ 252,171
Number of non-employee warrants subscribed							228,000
Capital revolution 2018 [member]
Capital structure [line items]
Options exercise						322,068
Exercise stock option						$ 230,629
Underwriting discounts and commissions						$ 178,611,687
Capital revolution 2018 [member] | BSA [member]
Capital structure [line items]
Ordinary shares issued						6,146,000
Number of employee warrants exercisable						1,867
Exercise stock option						$ 7,525,542
Number of non-employee warrants subscribed						160,000
BSPCE [member] | Capital revolution 2017 [member]
Capital structure [line items]
Ordinary shares issued							126,179
Number of employee warrants exercisable							121,492
Exercise stock option							$ 2,173,058
Free Shares [member] | Capital revolution 2017 [member]
Capital structure [line items]
Number of shares converted							466,950
Free Shares [member] | Capital revolution 2018 [member]
Capital structure [line items]
Ordinary shares issued						1,939
Free Shares [member] | Capital Revolution 2019 [member] | BSA [member]
Capital structure [line items]
Number of shares converted				35,600
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Capital - Disclosure of Share W

Capital - Disclosure of Share Warrants and Non-employee Warrants (Detail)	12 Months Ended
	Dec. 31, 2019shares$ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of options/warrants/ shares outstanding	9,968,633
Number of options/warrants/ shares granted	1,707,800
Number of options/warrants/ shares vested/exercised	35,600
Number of options/warrants/ shares voided	982,524
Number of options/warrants/ shares outstanding	10,658,309
Maximum of shares to be issued	10,659,071
Number of options/warrants/ shares exercisable	7,774,432
BSPCE E [member] | 7/27/2010 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	07/27/2010
Type	BSPCE E
Number of options/warrants/ shares outstanding	19,702
Number of options/warrants/ shares outstanding	19,702
Maximum of shares to be issued	20,464
Number of options/warrants/ shares exercisable	19,702
Weighted average exercise price | $ / shares	$ 7.97
Free Shares [member] | 5/18/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	05/18/2015
Type	Free shares
Number of options/warrants/ shares outstanding	15,600
Number of options/warrants/ shares vested/exercised	15,600
Free Shares [member] | 10/08/2018 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/08/2018
Type	Free shares
Number of options/warrants/ shares outstanding	43,000
Number of options/warrants/ shares vested/exercised	20,000
Number of options/warrants/ shares voided	20,000
Number of options/warrants/ shares outstanding	3,000
Maximum of shares to be issued	3,000
Free Shares [member] | 12/17/2018 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	12/17/2018
Type	Free shares
Number of options/warrants/ shares outstanding	13,000
Number of options/warrants/ shares outstanding	13,000
Maximum of shares to be issued	13,000
Free Shares [member] | 07/03/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	07/03/2019
Type	Free shares
Number of options/warrants/ shares granted	3,500
Number of options/warrants/ shares voided	1,000
Number of options/warrants/ shares outstanding	2,500
Maximum of shares to be issued	2,500
Free Shares [member] | 04/24/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	04/24/2019
Type	Free shares
Number of options/warrants/ shares granted	6,500
Number of options/warrants/ shares outstanding	6,500
Maximum of shares to be issued	6,500
Free Shares [member] | 07/16/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	07/16/2019
Type	Free shares
Number of options/warrants/ shares granted	9,000
Number of options/warrants/ shares voided	5,000
Number of options/warrants/ shares outstanding	4,000
Maximum of shares to be issued	4,000
Free Shares [member] | 11/06/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	11/06/2019
Type	Free shares
Number of options/warrants/ shares granted	21,500
Number of options/warrants/ shares outstanding	21,500
Maximum of shares to be issued	21,500
Free Shares [member] | 11/18/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	11/18/2019
Type	Free shares
Number of options/warrants/ shares granted	16,500
Number of options/warrants/ shares outstanding	16,500
Maximum of shares to be issued	16,500
BSA [member] | 3/27/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	03/27/2015
Type	BSA
Number of options/warrants/ shares outstanding	130,000
Number of options/warrants/ shares outstanding	130,000
Maximum of shares to be issued	130,000
Number of options/warrants/ shares exercisable	130,000
Weighted average exercise price | $ / shares	$ 38.45
BSA [member] | 5/18/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	05/18/2015
Type	BSA
Number of options/warrants/ shares outstanding	50,000
Number of options/warrants/ shares outstanding	50,000
Maximum of shares to be issued	50,000
Number of options/warrants/ shares exercisable	50,000
Weighted average exercise price | $ / shares	$ 29.58
BSA [member] | 9/8/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	09/08/2015
Type	BSA
Number of options/warrants/ shares outstanding	224,200
Number of options/warrants/ shares outstanding	224,200
Maximum of shares to be issued	224,200
Number of options/warrants/ shares exercisable	224,200
Weighted average exercise price | $ / shares	$ 28.01
BSA [member] | 3/14/2016 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	03/14/2016
Type	BSA
Number of options/warrants/ shares outstanding	147,025
Number of options/warrants/ shares outstanding	147,025
Maximum of shares to be issued	147,025
Number of options/warrants/ shares exercisable	147,025
Weighted average exercise price | $ / shares	$ 27.37
BSA [member] | 10/28/2016 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/28/2016
Type	BSA
Number of options/warrants/ shares outstanding	148,000
Number of options/warrants/ shares outstanding	148,000
Maximum of shares to be issued	148,000
Number of options/warrants/ shares exercisable	148,000
Weighted average exercise price | $ / shares	$ 18.68
BSA [member] | 10/11/2017 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/11/2017
Type	BSA
Number of options/warrants/ shares outstanding	200,000
Number of options/warrants/ shares outstanding	200,000
Maximum of shares to be issued	200,000
Number of options/warrants/ shares exercisable	133,333
Weighted average exercise price | $ / shares	$ 24.34
Stock options [member] | 3/24/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	03/24/2015
Type	Stock Options
Number of options/warrants/ shares outstanding	1,730,646
Number of options/warrants/ shares voided	117,652
Number of options/warrants/ shares outstanding	1,612,994
Maximum of shares to be issued	1,612,994
Number of options/warrants/ shares exercisable	1,612,994
Weighted average exercise price | $ / shares	$ 38.45
Stock options [member] | 9/8/2015 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	09/08/2015
Type	Stock Options
Number of options/warrants/ shares outstanding	1,770,000
Number of options/warrants/ shares voided	146,800
Number of options/warrants/ shares outstanding	1,623,200
Maximum of shares to be issued	1,623,200
Number of options/warrants/ shares exercisable	1,623,200
Weighted average exercise price | $ / shares	$ 27.55
Stock options [member] | 3/14/2016 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	03/14/2016
Type	Stock Options
Number of options/warrants/ shares outstanding	1,785,271
Number of options/warrants/ shares voided	132,676
Number of options/warrants/ shares outstanding	1,652,595
Maximum of shares to be issued	1,652,595
Number of options/warrants/ shares exercisable	1,549,308
Weighted average exercise price | $ / shares	$ 22.44
Stock options [member] | 10/28/2016 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/28/2016
Type	Stock Options
Number of options/warrants/ shares outstanding	2,369,689
Number of options/warrants/ shares voided	190,796
Number of options/warrants/ shares outstanding	2,178,893
Maximum of shares to be issued	2,178,893
Number of options/warrants/ shares exercisable	1,634,170
Weighted average exercise price | $ / shares	$ 17.90
Stock options [member] | 10/11/2017 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/11/2017
Type	Stock Options
Number of options/warrants/ shares outstanding	1,182,500
Number of options/warrants/ shares voided	222,500
Number of options/warrants/ shares outstanding	960,000
Maximum of shares to be issued	960,000
Number of options/warrants/ shares exercisable	480,000
Weighted average exercise price | $ / shares	$ 22.57
Stock options [member] | 10/08/2018 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	10/08/2018
Type	Stock Options
Number of options/warrants/ shares outstanding	100,000
Number of options/warrants/ shares voided	50,000
Number of options/warrants/ shares outstanding	50,000
Maximum of shares to be issued	50,000
Number of options/warrants/ shares exercisable	12,500
Weighted average exercise price | $ / shares	$ 24.80
Stock options [member] | 12/17/2018 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	12/17/2018
Type	Stock Options
Number of options/warrants/ shares outstanding	40,000
Number of options/warrants/ shares outstanding	40,000
Maximum of shares to be issued	40,000
Number of options/warrants/ shares exercisable	10,000
Weighted average exercise price | $ / shares	$ 18.37
Stock options [member] | 07/03/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	07/03/2019
Type	Stock Options
Number of options/warrants/ shares granted	3,000
Number of options/warrants/ shares voided	3,000
Weighted average exercise price | $ / shares	$ 15.69
Stock options [member] | 04/24/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	04/24/2019
Type	Stock Options
Number of options/warrants/ shares granted	1,562,800
Number of options/warrants/ shares voided	93,100
Number of options/warrants/ shares outstanding	1,469,700
Maximum of shares to be issued	1,469,700
Weighted average exercise price | $ / shares	$ 18.25
Stock options [member] | 11/06/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	11/06/2019
Type	Stock Options
Number of options/warrants/ shares granted	55,000
Number of options/warrants/ shares outstanding	55,000
Maximum of shares to be issued	55,000
Weighted average exercise price | $ / shares	$ 11.06
Stock options [member] | 11/18/2019 [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Date	11/18/2019
Type	Stock Options
Number of options/warrants/ shares granted	30,000
Number of options/warrants/ shares outstanding	30,000
Maximum of shares to be issued	30,000
Weighted average exercise price | $ / shares	$ 12.33

Capital - Schedule of Informati

Capital - Schedule of Information Relating to Subsidiaries that Reported Non-Controlling Interest (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Disclosure of non-controlling interests [line items]
Revenue	$ 15,190	[1]	$ 12,731	$ 25,188
Net Profit (Loss)	(115,212)	[1]	(88,333)	(103,683)
Net Profit (Loss) attributable to NCI	(13,121)	[1]	(9,640)	(4,315)
Other comprehensive income	(6,000)		(19,122)	22,997
Total comprehensive income	(121,212)		(107,455)	(80,686)
Total comprehensive income attributable to NCI	(12,856)		(10,330)	$ (4,723)
Current assets	391,520	[1]	487,641		$ 485,502
Non-current assets	75,949	[1]	13,199		49,460
Current liabilities	62,604	[1]	46,869		49,910
Non-current liabilities	49,395	[1]	3,699		$ 34,779
Calyxt Inc. [member]
Disclosure of non-controlling interests [line items]
Revenue	7,294		236
Net Profit (Loss)	(40,142)		(28,517)
Net Profit (Loss) attributable to NCI	(13,121)		(9,640)
Other comprehensive income	(1,237)		(5,373)
Total comprehensive income	(41,378)		(33,891)
Total comprehensive income attributable to NCI	(12,856)		(10,330)
Current assets	63,528		97,735
Non-current assets	22,518		4,539
Current liabilities	6,642		5,460
Non-current liabilities	15,121		826
Net assets	64,283		95,987
Net assets attributable to NCI	$ 19,973		$ 29,257
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Share-based Payments - Addition

Share-based Payments - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Expected dividend yield		0.00%
Vesting period, years	4 years
Stock option expire, years	10 years
Share based arrangement number of other equity instruments granted | shares	1,707,800
Calyxt Inc. [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	$ 4.4	$ 3.3	$ 5.2
Stock options [member] | Calyxt Inc. [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Stock option expire, years	10 years
Expected dividend yield type description		U.S. Treasury zero-coupon yield
Performance Stock Unit [Member] | Calyxt Inc. [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share based arrangement number of other equity instruments granted | shares	311,667
Share based payment expense	$ 0.2
Performance Stock Unit [Member] | Calyxt Inc. [member] | Bottom of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share Based Payment Arrangement Percentage Payout	0.00%
Performance Stock Unit [Member] | Calyxt Inc. [member] | Top of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share Based Payment Arrangement Percentage Payout	120.00%
Performance Stock Unit [Member] | Calyxt Inc. [member] | Performance Period [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share Based Arrangement Service Period	3 years
Performance Stock Unit [Member] | Calyxt Inc. [member] | Restricted Period [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share Based Arrangement Service Period	2 years
Stock options [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	$ 13.4	$ 26	36.8
Stock options [member] | Calyxt Inc. [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	6.8	$ 3.2	3.8
Vesting period of warrants		6 years
Warrants [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	0.9	$ 2.3	3.5
S A free shares [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	0.7	$ 0.2	$ 2.6
Vesting description		The free shares granted prior to 2018 are subject to a two-year vesting period for French employees and four years for foreign citizens. The free shares granted in 2018 are subject to a one-year vesting period for French employees and two-years for foreign citizens.
Dividend yield		0.00%
S A free shares [member] | French employees [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period, years		1 year	2 years
S A free shares [member] | Foreign citizens [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting period, years		2 years	4 years
RSU Calyxt 2017 [member] | Calyxt Inc. [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based compensation expense	$ 4.9	$ 5.5	$ 4.7
Vesting description	Restricted stock units generally vest and become unrestricted over five years after the date of grant.

Share-based Payments - Summary

Share-based Payments - Summary of assumptions Vesting Details (Detail) - Equity awards [member] - € / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted-Average fair values of stock options granted	€ 10.19	€ 8.84	€ 14.30
Share entitlement per options	€ 1	€ 1	€ 1
Expected term (in years)		6 years 3 months
Vesting conditions	Service	Service	Service
Vesting period	Graded	Graded	Graded
Bottom of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	(0.38%)	0.13%
Exercise price	€ 11.06	€ 18.37
Grant date share fair value	€ 11.32	€ 16
Expected volatility	60.00%	63.30%	65.60%
Expected term (in years)	5 years 9 months 10 days
Top of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	0.09%	0.21%	0.03%
Exercise price	€ 18.25	€ 24.80	€ 22.57
Grant date share fair value	€ 17.80	€ 17.78	€ 24.01
Expected volatility	66.60%	63.40%
Expected term (in years)	6 years 3 months		6 years 1 month 13 days

Share-Based Payments - Summar_2

Share-Based Payments - Summary of Information on Stock Option Activity (Detail) - Stock options [member]	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)	Dec. 31, 2017USD ($)	Dec. 31, 2017EUR (€)
Disclosure Of Number And Weighted Average Exercise Prices Of Share Options and awards [Line Items]
Option exercisable, beginning balance	5,644,044	5,644,044			3,822,772	3,822,772
Option exercisable, ending balance	6,922,172	6,922,172	5,644,044	5,644,044
Weighted- average exercise price per share, beginning balance | €		€ 27.47				€ 28.02
Weighted- average exercise price per share, exercised | €
Weighted- average exercise price per share, ending balance | €		€ 26.30		€ 27.47
Option outstanding, beginning balance	8,978,106	8,978,106			9,332,604	9,332,604
Option outstanding, granted	1,650,800	1,650,800	140,000	140,000
Option outstanding, exercised	0	0	(319,568)	(319,568)
Option outstanding, forfeited or expired	(956,524)	(956,524)	(174,930)	(174,930)
Option outstanding, ending balance	9,672,382	9,672,382	8,978,106	8,978,106
Weighted average exercise price per share, beginning balance | €		€ 25.36				€ 25.17
Weighted average exercise price per share, granted | €		17.90		€ 22.96
Weighted average exercise price per share, exercised | €		0		19.72
Weighted average exercise price per share, forfeited or expired | €		24.01		23.68
Weighted average exercise price per share, ending balance | €		€ 24.22		€ 25.36
Remaining Average Useful Life	6 years 9 months 18 days	6 years 9 months 18 days	7 years 3 months 18 days	7 years 3 months 18 days	8 years 3 months 18 days	8 years 3 months 18 days
Calyxt Inc. [member]
Disclosure Of Number And Weighted Average Exercise Prices Of Share Options and awards [Line Items]
Option exercisable, beginning balance	1,278,038	1,278,038			1,244,968	1,244,968
Option exercisable, ending balance	1,789,567	1,789,567	1,278,038	1,278,038
Weighted- average exercise price per share, beginning balance | $	$ 7.45				$ 5.20
Weighted- average exercise price per share, ending balance | $	$ 8.73		$ 7.45
Option outstanding, beginning balance	3,201,887	3,201,887			3,883,432	3,883,432
Option outstanding, granted	1,590,000	1,590,000	554,243	554,243
Option outstanding, exercised	(95,327)	(95,327)	(592,342)	(592,342)
Option outstanding, forfeited or expired	(227,696)	(227,696)	(643,446)	(643,446)
Option outstanding, other activity	12,495	12,495
Option outstanding, ending balance	4,481,359	4,481,359	3,201,887	3,201,887
Weighted average exercise price per share, beginning balance | $	$ 10.67				$ 9.16
Weighted average exercise price per share, granted | $	13.80		$ 16.69
Weighted average exercise price per share, exercised | $	3.61		4.43
Weighted average exercise price per share, forfeited or expired | $	14.68		12.52
Weighted average exercise price per share, other activity | $	13.29
Weighted average exercise price per share, ending balance | $	$ 11.73		$ 10.67
Remaining Average Useful Life	6 years 9 months 18 days	6 years 9 months 18 days	8 years 2 months 12 days	8 years 2 months 12 days	8 years 9 months 18 days	8 years 9 months 18 days

Share-Based Payments - Summar_3

Share-Based Payments - Summary of assumptions Weighted-average Fair Values of Warrants Granted and Assumptions Used for Black-Scholes Option Pricing Model (Detail) - Warrants [member] - € / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted-Average fair values of warrants granted	€ 13.20	€ 9.33
Risk-free interest rate	0.12%
Share entitlement per options	€ 1	€ 1
Exercise price	24.34
Grant date share fair value	€ 24.95
Expected volatility	64.70%
Expected term (in years)	6 years	6 years
Vesting conditions	Service	Service
Vesting period	Graded	Graded
Bottom of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate		0.00%
Exercise price		€ 18.68
Grant date share fair value		€ 16.42
Expected volatility		62.80%
Top of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate		0.04%
Exercise price		€ 27.37
Grant date share fair value		€ 22.48
Expected volatility		63.10%

Share-Based Payments - Summar_4

Share-Based Payments - Summary of Information on Warrants Activity (Detail) - Warrants [member]	12 Months Ended
	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2017EUR (€)
Disclosure Of Number And Weighted Average Exercise Prices Of Share Options and awards [Line Items]
Option exercisable, beginning balance	852,260	687,252	469,436
Option exercisable, ending balance		852,260	687,252
Weighted- average exercise price per share, beginning balance	€ 35.35	€ 27.74	€ 28.80
Weighted- average exercise price per share, exercised
Weighted- average exercise price per share, ending balance		€ 35.35	€ 27.74
Option outstanding, beginning balance	918,927	918,927	1,100,969
Warrants outstanding, granted		0	0
Warrants outstanding, exercised		0	(1,867)
Warrants outstanding, forfeited or expired		0	(180,175)
Option outstanding, ending balance		918,927	918,927
Weighted average exercise price per share, beginning balance	€ 35.12	€ 26.74	€ 27.23
Weighted average exercise price per share, granted		0	0
Weighted average exercise price per share, exercised		0	6.16
Weighted average exercise price per share, forfeited or expired		0	29.95
Weighted average exercise price per share, ending balance		€ 35.12	€ 26.74
Remaining Average Useful Life	6 years 10 months 24 days	7 years 2 months 12 days	8 years 2 months 12 days

Share-Based Payment - Summary o

Share-Based Payment - Summary of Number of Shares Outstanding and Weighted Average Grant Date Fair Value (Detail) - S A free shares [member]	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of free shares outstanding, beginning balance	71,600	71,600	15,600	15,600
Number of free shares outstanding, granted	57,000	57,000	56,000	56,000
Number of free shares outstanding, vested	(35,600)	(35,600)	0	0
Number of free shares outstanding, cancelled	(26,000)	(26,000)	0	0
Number of free shares outstanding, ending balance	67,000	67,000	71,600	71,600
Weighted average grant date fair value, beginning balance				€ 28.17
Weighted average grant date fair Value, granted		€ 13.04		17.37
Weighted average grant date fair value, vested		25.74		0
Weighted average grant date fair Value, cancelled		€ 21.65		€ 0
Weighted average grant date fair value, ending balance | $	$ 13.98		$ 27.37

Share-Based Payments - Calyxt E

Share-Based Payments - Calyxt Eqity Summary of assumptions Vesting Details (Detail) - Calyxt Inc. [member] - Stock options [member] - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted-Average fair values of stock options granted	$ 10.21	$ 9.09	$ 4
Risk-free interest rate			1.96%
Share entitlement per options	$ 1	$ 1	$ 1
Exercise price			13.29
Grant date share fair value			$ 13.29
Expected volatility			25.00%
Expected term (in years)			6 years 7 months 6 days
Vesting conditions	Service	Service	Service
Vesting period	Graded	Graded	Graded
Bottom of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	1.70%	2.45%
Exercise price	$ 4.05	$ 14.24
Grant date share fair value	$ 4.05	$ 14.24
Expected volatility	52.60%	40.86%
Expected term (in years)	6 years 9 months 18 days	5 years 7 months 6 days
Top of Range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Risk-free interest rate	2.50%	2.89%
Exercise price	$ 15.39	$ 23.39
Grant date share fair value	$ 15.39	$ 23.39
Expected volatility	78.90%	57.22%
Expected term (in years)	10 years	10 years

Share-Based Payments - Summar_5

Share-Based Payments - Summary of Number of Shares Outstanding and Weighted Average Grant Date Fair Value (Detail) - RSU Calyxt 2017 [member] - Calyxt Inc. [member]	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of free shares outstanding, beginning balance	1,051,414	1,373,933
Number of restricted stock units outstanding, granted	100,000	315,825
Number of restricted stock units outstanding, vested	(324,043)	(261,507)
Number of restricted stock units outstanding, cancelled	(13,845)	(376,837)
Number of free shares outstanding, ending balance	813,526	1,051,414
Weighted average grant date fair value, beginning balance		$ 13.29
Weighted average grant date fair Value, granted	$ 12.48	16.68
Weighted average grant date fair value, vested	9.69	14.07
Weighted average grant date fair Value, cancelled	12.72	13.30
Weighted average grant date fair value, ending balance	$ 9.41	$ 14.11

Share-Based Payments - Detailed

Share-Based Payments - Detailed Description Inputs Stock Options Granted Performance Stock (Detail) - Performance Stock Unit [Member] - Calyxt [Member]	Jun. 28, 2019yr$ / shares
Disclosure Description Of Inputs Stock Options Granted Performance Stock [Line Items]
Estimated fair values of performance stock units granted | $ / shares	$ 7.06
Assumptions:
Risk-free interest rate	1.71%
Expected volatility	75.00%
Expected term (in years) | yr	3

Share-Based Payments - Detail_2

Share-Based Payments - Detailed Disclosure Detail Of Stock Unit Activity Performance Stock (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)shares
Disclosure Detail Of Stock Unit Activity Performance Stock [Line Items]
Number of performance stock units outstanding, Granted	1,707,800
Number of performance stock units outstanding, Vested	35,600
Number of performance stock units outstanding, Cancelled	982,524
Performance Stock Unit [Member] | Calyxt [Member]
Disclosure Detail Of Stock Unit Activity Performance Stock [Line Items]
Number of free shares outstanding, beginning balance	0
Number of performance stock units outstanding, Granted	311,667
Number of performance stock units outstanding, Vested	0
Number of performance stock units outstanding, Cancelled	0
Number of free shares outstanding, ending balance	311,667
Weighted average grant date fair value, beginning balance | $	$ 0
Weighted average grant date fair Value, granted | $	7.06
Weighted average grant date fair value, vested | $	0
Weighted average grant date fair Value, cancelled | $	0
Weighted average grant date fair value, ending balance | $	$ 7.06

Earnings Per Share - Details of

Earnings Per Share - Details of Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Earnings per share [abstract]
Net income (loss) attributable to shareholders of Cellectis ($ in thousands)	$ (102,091)		$ (78,693)	$ (99,368)
Adjusted weighted average number of outstanding shares, used to calculate both basic and diluted net result per share	42,442,136		40,774,197	35,690,636
Basic net income (loss) per share ($ /share)	$ (2.41)	[1]	$ (1.93)	$ (2.78)
Diluted net income (loss) per share ($ /share)	$ (2.41)	[1]	$ (1.93)	$ (2.78)
[1]	The 2019 Consolidated Financial Statements have been prepared according to the new IFRS 16 “Leases” standard with a new “right-of-use assets” category and a resulting significant increase of “lease debts” compared to the previous period (see note 2.2 for discussion of the application of IFRS 16 “Leases” from January 1, 2019 under the modified retrospective transition method). Prior periods have not been restated for the adoption.

Provisions - Summary of Provisi

Provisions - Summary of Provisions for Termination Benefits (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Disclosure of other provisions [line items]
Beginning balance		$ 4,211		$ 4,858
Additions		4,323		1,003
Amounts used during the period		(2,099)		(888)
Pension, Reversals		(92)		(577)
OCI		253		(186)
Ending balance		6,598		4,211
Non current provisions beginning balance		2,681		3,430
Non current provisions additions		314		314
Non current provisions Amounts used during period				(888)
Non current provisions OCI		263		(175)
Non current provisions Ending balance		2,855		2,681
Current provisions beginning balance		1,528		1,427
Current provisions additions		4,009		688
Current provisions Amounts used during period		(2,099)
Current provisions Reversals		(92)		(577)
Current provisions OCI		(10)		(11)
Current provisions Ending balance		3,743		1,528
Restated [member]
Disclosure of other provisions [line items]
Beginning balance		3,169
Ending balance				3,169
Non current provisions beginning balance		2,278
Non current provisions Ending balance				2,278
Current provisions beginning balance		891
Current provisions Ending balance				891
Reclassification [member]
Disclosure of other provisions [line items]
Beginning balance		1,043
Ending balance				1,043
Current provisions beginning balance		1,043
Current provisions Ending balance				1,043
Pension [member]
Disclosure of other provisions [line items]
Beginning balance		2,278		2,193
Pension, Additions		314		314
Pension, Amounts used during the period				(54)
OCI		263		(175)
Ending balance		2,855		2,278
Pension [member] | Restated [member]
Disclosure of other provisions [line items]
Beginning balance		2,278
Ending balance				2,278
Loss on Contract [member]
Disclosure of other provisions [line items]
Loss on contract, Beginning balance		1,043		1,876
Loss on contract, Additions	[1]	690
Loss on contract, Amounts used during the period		(1,461)	[1]	(834)
Loss on contract, OCI				1
Loss on contract, Ending balance		272	[1]	1,043
Loss on Contract [member] | Reclassification [member]
Disclosure of other provisions [line items]
Loss on contract, Beginning balance	[1]	1,043
Loss on contract, Ending balance	[1]			1,043
Employee Litigation and Severance [member]
Disclosure of other provisions [line items]
Additions		700
Employee litigation and severance, Beginning balance		41		1
Employee litigation and severance, Additions		715		43
Employee litigation and severance, Amounts used during the period		(43)
Employee litigation and severance, Reversals		(75)		(1)
Employee litigation and severance, OCI		1		(2)
Employee litigation and severance, Ending balance				41
Employee Litigation and Severance [member] | Restated [member]
Disclosure of other provisions [line items]
Employee litigation and severance, Beginning balance		41
Employee litigation and severance, Ending balance				41
Commercial litigation [member]
Disclosure of other provisions [line items]
Additions				600
Commercial litigation, Beginning balance		850		782
Commercial litigation, Additions		2,604		646
Commercial litigation, Amounts used during the period		(595)
Commercial litigation, Reversals		(17)		(570)
Commercial litigation, OCI		(11)		(8)
Commercial litigation, Ending balance		2,832		850
Commercial litigation [member] | Restated [member]
Disclosure of other provisions [line items]
Commercial litigation, Beginning balance		$ 850
Commercial litigation, Ending balance				850
Redundancy Plan [member]
Disclosure of other provisions [line items]
Redundancy plan, Beginning balance				7
Redundancy plan, Reversals				(6)
Redundancy plan, OCI				$ (1)
[1]	As of January 1, 2019, Montvale, New Jersey facility lease agreement provision for loss on contract was scoped under IFRS 16 and classified as lease debts. During the period, the agreement has been discontinued which changed its treatment placing it outside the scope of IFRS 16 and resulting in the reclassification to “loss on contract” presented above.

Provisions - Additional Informa

Provisions - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of provisions [line items]
Provisions for termination benefits	$ 4,323,000	$ 1,003,000
Defined benefit plan	$ 2,855,000	2,278,000	$ 2,194,000	$ 562,000
Employee termination, legal compensation calculation	Seniority conditions the employee must justify to be entitled to an indemnity of 8 working months against one year before. Calculation of the allowance 1/4 of a month of salary per year of seniority up to 10 years, against 1/5 before, and no change beyond the 11th year.
Operating charges with suppliers [Member]
Disclosure of provisions [line items]
Provisions for termination benefits	$ 2,600,000	600,000
Pension service cost [member]
Disclosure of provisions [line items]
Provisions for termination benefits	300,000	300,000
Operating lease rentals [member]
Disclosure of provisions [line items]
Provisions for termination benefits		800,000
Commercial litigation [member]
Disclosure of provisions [line items]
Provisions for termination benefits		600,000
Discontinuation Of The Lease [Member]
Disclosure of provisions [line items]
Provisions for termination benefits	700,000
Employee Litigation and Severance [member]
Disclosure of provisions [line items]
Provisions for termination benefits	700,000
United States [member]
Disclosure of provisions [line items]
Actuarial liabilities of benefit plan	0
France [member]
Disclosure of provisions [line items]
Defined benefit plan	$ 1,100,000	$ 1,500,000	$ 800,000

Provisions - Schedule of Estima

Provisions - Schedule of Estimation of Retirement Indemnity to Employee (Detail) - Years	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of defined benefit plans [abstract]
% social security contributions	45.00%	45.00%	45.00%
Salary increases	3.50%	3.50%	3.50%
Discount rate	1.00%	1.75%	1.75%
Terms of retirement	voluntary retirement	voluntary retirement	voluntary retirement
Retirement age	0	65	65

Provisions - Summary of Net Def

Provisions - Summary of Net Defined Benefit Liability and Components (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of net defined benefit liability (asset) [abstract]
Beginning balance	$ (2,278)	$ (2,194)	$ (562)
Current service cost	(275)	(276)	(925)
Interest cost	(39)	(38)	(24)
Benefit paid		54
Actuarial gains and losses	(303)	70	(515)
Reclassification/CTA	40	105	(168)
Ending balance	$ (2,855)	$ (2,278)	$ (2,194)

Commitments - Schedule of Commi

Commitments - Schedule of Commitments (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Disclosure of contingent liabilities [line items]
Total contractual obligations	$ 190,728
Lease agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	73,181
License Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	18,607
Manufacturing Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	6,218
Other Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	50,896
Clinical & R&D agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	2,086
Construction agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	39,741
Less than One Year [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	83,637
Less than One Year [member] | Lease agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	4,014
Less than One Year [member] | License Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	1,389
Less than One Year [member] | Manufacturing Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	6,218
Less than One Year [member] | Other Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	30,851
Less than One Year [member] | Clinical & R&D agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	1,424
Less than One Year [member] | Construction agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	39,741
1-3 years [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	42,371
1-3 years [member] | Lease agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	18,886
1-3 years [member] | License Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	2,778
1-3 years [member] | Other Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	20,045
1-3 years [member] | Clinical & R&D agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	662
3-5 years [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	12,542
3-5 years [member] | Lease agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	9,764
3-5 years [member] | License Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	2,778
More than Five Years [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	52,179
More than Five Years [member] | Lease agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	40,516
More than Five Years [member] | License Agreements [member]
Disclosure of contingent liabilities [line items]
Total contractual obligations	$ 11,662

Related Parties - Additional In

Related Parties - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Agreementshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019€ / shares
Disclosure of transactions between related parties [line items]
Key management personnel compensation, short-term employee benefits | $	$ 5,200,000	$ 4,400,000	$ 3,600,000
Key management personnel compensation, share-based payments in shares	602
Key management personnel non-cash stock-based compensation expense recognized | $	$ 2,500,000
Mr. Godard [member]
Disclosure of transactions between related parties [line items]
Number of service agreements | Agreement	2
Compensation paid for consultancy services | $	$ 71,000	70,000	38,000
Transactions with related parties, amount outstanding | $	$ 0	$ 0	$ 0
Mr. Godard [member] | Non-Employee Warrant One [member]
Disclosure of transactions between related parties [line items]
Number of non-employee warrants exercisable to obtain shares	220,175
Number of shares to be obtained upon exercise of warrants	50,000
Number of shares to be obtained upon exercise of warrants, strike price | € / shares				€ 38.45
Mr. Godard [member] | Non-Employee Warrant Two [member]
Disclosure of transactions between related parties [line items]
Number of non-employee warrants exercisable to obtain shares	50,000
Number of shares to be obtained upon exercise of warrants	50,000
Number of shares to be obtained upon exercise of warrants, strike price | € / shares				28.01
Mr. Godard [member] | Non-Employee Warrant Three [member]
Disclosure of transactions between related parties [line items]
Number of non-employee warrants exercisable to obtain shares	40,175
Number of shares to be obtained upon exercise of warrants	40,175
Number of shares to be obtained upon exercise of warrants, strike price | € / shares				27.37
Mr. Godard [member] | Non-Employee Warrant Four [member]
Disclosure of transactions between related parties [line items]
Number of non-employee warrants exercisable to obtain shares	40,000
Number of shares to be obtained upon exercise of warrants	40,000
Number of shares to be obtained upon exercise of warrants, strike price | € / shares				18.68
Mr. Godard [member] | Non Employee Warrant Five [member]
Disclosure of transactions between related parties [line items]
Number of non-employee warrants exercisable to obtain shares	40,000
Number of shares to be obtained upon exercise of warrants	40,000
Number of shares to be obtained upon exercise of warrants, strike price | € / shares				€ 24.34

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Jan. 01, 2020 - Allo five zero one and five zero one A [member] - Amendment to license agreement [member] € in Millions, $ in Millions	USD ($)	EUR (€)
Upfront payment [member]
Disclosure of non-adjusting events after reporting period [line items]
Milestone payment received in advance		€ 25
Development And Commercial Milestones [Member]
Disclosure of non-adjusting events after reporting period [line items]
Potential milestones to receive	$ 410	€ 370