DBV Technologies (DBVT) 10-Q 26 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 26, 2021
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	DBV TECHNOLOGIES S.A.
Entity Central Index Key	0001613780
Entity File Number	001-36697
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Address, Postal Zip Code	92120
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		55,011,687
Document Quarterly Report	true
Document Transition Report	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Address, Country	FR
Entity Small Business	true
Entity Incorporation, State or Country Code	I0
Entity Address, Address Line One	177-181 avenue Pierre Brossolette
Entity Address, City or Town	Montrouge
City Area Code	33
Local Phone Number	1 55 42 78 78
Entity Tax Identification Number	00-0000000
American Depositary Share [Member]
Document Information [Line Items]
Title of 12(b) Security	American Depositary Shares, each representing one-half of one ordinary share, nominal value €0.10 per share
Trading Symbol	DBVT
Security Exchange Name	NASDAQ
Ordinary Shares [Member]
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, nominal value €0.10 per share
No Trading Symbol Flag	true
Security Exchange Name	NASDAQ

Condensed Consolidated Statemen

Condensed Consolidated Statements of Financial Position - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 98,195	$ 196,352
Trade receivables		2,230
Other current assets	11,943	8,792
Total current assets	110,138	207,375
Non-Current assets
Property, plant, and equipment, net	19,273	24,792
Right-of-use assets related to operating leases	7,876	10,104
Intangible assets	26	41
Other non-current assets	33,612	29,935
Total non-current assets	60,786	64,871
Total Assets	170,924	272,246
Current liabilities:
Trade payables	12,170	20,338
Short-term operating leases	2,657	3,708
Short-term financial debt	695	724
Current contingencies	5,633	5,016
Other current liabilities	12,659	22,926
Total current liabilities	33,814	52,713
Non-Current liabilities
Long-term operating leases	8,298	10,496
Long-term financial debt		543
Non-current contingencies	7,629	2,527
Other non-current liabilities	4,292	475
Total non-current liabilities	20,218	14,042
Total Liabilities	54,033	66,754
Shareholders' equity :
Ordinary shares, €0.10 par value; 55,011,687 and 54,929,187 shares authorized, and issued as at September 30, 2021 and December 31, 2020, respectively, and 3,946,548 and 4,029,763 shares outstanding as at September 30, 2021 and December 31, 2020, respectively	6,529	6,518
Additional paid-in capital	359,081	1,152,042
Treasury stock, 75,400 and 112,302 ordinary shares as of September 30, 2021 and December 31, 2020, respectively, at cost	(810)	(1,169)
Accumulated deficit	(244,856)	(958,543)
Accumulated other comprehensive income	474	484
Accumulated currency translation effect	(3,526)	6,158
Total Shareholders' equity	116,892	205,491
Total Liabilities and Shareholders' Equity	$ 170,924	$ 272,246

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Financial Position (Parenthetical) - € / shares	Sep. 30, 2021	Dec. 31, 2020
Treasury stock, common, shares	75,400	112,302
Common Shares [Member]
Common stock shares par value	€ 0.10	€ 0.10
Common stock shares authorized	55,011,687	54,929,187
Common stock shares issued	55,011,687	54,929,187
Common stock shares outstanding	3,946,548	4,029,763

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues
Operating income	$ 1,323	$ 4,158	$ 2,776	$ 12,488
Operating expenses
Research and development expenses	(16,320)	(25,751)	(58,663)	(75,214)
Sales and Marketing expenses	(1,072)	(1,595)	(2,999)	(8,114)
General and administrative expenses	(8,299)	(6,863)	(26,250)	(26,838)
Restructuring expenses		286		(21,003)
Total Operating expenses	(25,691)	(33,923)	(87,912)	(131,169)
Loss from operations	(24,368)	(29,765)	(85,137)	(118,681)
Other Income (expenses)
Financial income (expense)	336	(1,184)	597	(1,380)
Loss before taxes	(24,033)	(30,948)	(84,540)	(120,061)
Income tax		(7)	404	(10)
Net loss	(24,033)	(30,955)	(84,136)	(120,071)
Foreign currency translation differences, net of taxes	(3,728)	13,196	(9,684)	13,495
Actuarial gains (losses) on employee benefits, net of taxes	28	(75)	(10)	(113)
Comprehensive loss	$ (27,733)	$ (17,834)	$ (93,830)	$ (106,688)
Basic/diluted net loss per share attributable to shareholders	$ (0.44)	$ (0.56)	$ (1.53)	$ (2.23)
Weighted average shares outstanding used in computing per share amounts:	54,947,354	54,843,843	54,911,278	53,852,176

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement of Cash Flows [Abstract]
Net loss for the period	$ (84,136)	$ (120,071)
Cash flows used in operating activities:
Depreciation, amortization and accrued contingencies	9,705	18,360
Retirement pension obligations	127	(650)
Expenses related to share-based payments	4,078	(2,965)
Other elements	1,214	789
Changes in operating assets and liabilities:
Decrease (increase) in inventories and work in progress		2,292
Decrease (increase) in trade receivables	2,174	(1,974)
Decrease (increase) in other current assets	(9,036)	(9,591)
(Decrease) increase in trade payables	(7,135)	(6,760)
(Decrease) increase in other current and non-current liabilities	(5,497)	(11,372)
Change in operating lease liabilities and right—of—use assets	(946)	(136)
Net cash flow used in operating activities	(89,452)	(132,076)
Cash flows provided by (used in) investing activities:
Acquisitions of property, plant, and equipment, net from proceeds	46	(2,200)
Acquisitions of intangible assets	(8)	(20)
Acquisitions of non-current financial assets	3	(12)
Net cash flows provided by (used in) investing activities	41	(2,232)
Cash flows (used in) provided by financing activities:
(Decrease) increase in conditional advances	(518)	(138)
Treasury shares	(359)	(766)
Capital increases, net of transaction costs	794	150,551
Other cash flows related to financing activities	(21)	(24)
Net cash flows (used in) provided by financing activities	(103)	149,624
Effect of exchange rate changes on cash and cash equivalents	(8,643)	12,834
Net (decrease) increase in cash and cash equivalents	(98,157)	28,150
Net Cash and cash equivalents at the beginning of the period	196,352	193,255
Net cash and cash equivalents at the end of the period	$ 98,195	$ 221,404

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Shares [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive income (loss) [Member]	Accumulated Currency Translation Effect [Member]
Beginning balance at Dec. 31, 2019	$ 193,186	$ 5,645	$ 1,003,595	$ (230)	$ (798,988)	$ 108	$ (16,945)
Beginning balance (Shares) at Dec. 31, 2019		47,028,510
Net (loss)	(40,913)				(40,913)
Other comprehensive income (loss)	(5,875)					189	(6,064)
Issuance of ordinary shares	151,023	$ 873	150,150
Issuance of ordinary shares (Shares)		7,898,677
Treasury shares	(832)			(832)
Share-based payments	3,073		3,073
Ending balance at Mar. 31, 2020	299,662	$ 6,518	1,156,818	(1,062)	(839,901)	297	(23,009)
Ending balance (Shares) at Mar. 31, 2020		54,927,187
Beginning balance at Dec. 31, 2019	193,186	$ 5,645	1,003,595	(230)	(798,988)	108	(16,945)
Beginning balance (Shares) at Dec. 31, 2019		47,028,510
Net (loss)	(120,071)
Ending balance at Sep. 30, 2020	233,099	$ 6,518	1,150,309	(1,214)	(919,058)	(5)	(3,450)
Ending balance (Shares) at Sep. 30, 2020		54,927,187
Beginning balance at Mar. 31, 2020	299,662	$ 6,518	1,156,818	(1,062)	(839,901)	297	(23,009)
Beginning balance (Shares) at Mar. 31, 2020		54,927,187
Net (loss)	(48,203)				(48,203)
Other comprehensive income (loss)	6,136					(227)	6,363
Treasury shares	107			107
Share-based payments	(5,964)		(5,964)
Ending balance at Jun. 30, 2020	251,739	$ 6,518	1,150,855	(955)	(888,103)	70	(16,646)
Ending balance (Shares) at Jun. 30, 2020		54,927,187
Net (loss)	(30,955)				(30,955)
Other comprehensive income (loss)	13,121					(75)	13,196
Issuance of ordinary shares	(472)		(472)
Treasury shares	(260)			(260)
Share-based payments	(74)		(74)
Ending balance at Sep. 30, 2020	233,099	$ 6,518	1,150,309	(1,214)	(919,058)	(5)	(3,450)
Ending balance (Shares) at Sep. 30, 2020		54,927,187
Beginning balance at Dec. 31, 2020	205,491	$ 6,518	1,152,042	(1,169)	(958,543)	484	6,158
Beginning balance (Shares) at Dec. 31, 2020		54,929,187
Net (loss)	(29,449)				(29,449)
Other comprehensive income (loss)	(8,829)					(85)	(8,744)
Issuance of ordinary shares	42	$ 1	42
Issuance of ordinary shares (Shares)		7,500
Treasury shares	488			488
Share-based payments	1,433		1,433
Ending balance at Mar. 31, 2021	169,176	$ 6,519	1,153,516	(681)	(987,992)	399	(2,586)
Ending balance (Shares) at Mar. 31, 2021		54,936,687
Beginning balance at Dec. 31, 2020	205,491	$ 6,518	1,152,042	(1,169)	(958,543)	484	6,158
Beginning balance (Shares) at Dec. 31, 2020		54,929,187
Net (loss)	(84,136)
Ending balance at Sep. 30, 2021	116,892	$ 6,529	359,081	(810)	(244,856)	474	(3,526)
Ending balance (Shares) at Sep. 30, 2021		55,011,687
Beginning balance at Mar. 31, 2021	169,176	$ 6,519	1,153,516	(681)	(987,992)	399	(2,586)
Beginning balance (Shares) at Mar. 31, 2021		54,936,687
Net (loss)	(30,654)				(30,654)
Other comprehensive income (loss)	2,836			0		48	2,788
Issuance of ordinary shares	473	$ 9	464
Issuance of ordinary shares (Shares)		75,000
Issuance of warrants	279		279
Treasury shares	(185)			(185)
Share-based payments	1,094		1,094
Allocation of accumulated net losses			(797,823)		797,823
Ending balance at Jun. 30, 2021	143,019	$ 6,529	357,530	(866)	(220,823)	446	203
Ending balance (Shares) at Jun. 30, 2021		55,011,687
Net (loss)	(24,033)				(24,033)
Other comprehensive income (loss)	(3,701)					28	(3,728)
Treasury shares	56			56
Share-based payments	1,551		1,551
Ending balance at Sep. 30, 2021	$ 116,892	$ 6,529	$ 359,081	$ (810)	$ (244,856)	$ 474	$ (3,526)
Ending balance (Shares) at Sep. 30, 2021		55,011,687

The Company

The Company	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
The Company	Note 1: The Company Incorporated in 2002 under the laws of France, DBV Technologies S.A. (“DBV Technologies,” or the “Company”, or the “group”) is a clinical-stage specialty biopharmaceutical company focused on changing the field of immunotherapy by developing a novel technology platform called Viaskin ™ ™ ™ Basis of Presentation The condensed consolidated financial statements of the Company and its wholly-owned subsidiaries are unaudited and have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and are presented in U.S. dollars. The amounts are presented in thousands unless otherwise indicated. All significant intercompany accounts and transactions between the Company and its subsidiaries have been eliminated on consolidation. The unaudited condensed consolidated financial statements presented in this Quarterly Report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted from these interim financial statements. However, these condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of management, necessary to fairly state the results of the interim period. These interim financial results are not necessarily indicative of results to be expected for the full fiscal year ending December 31, 2021, or any other future period. Use of estimates The preparation of the Company’s condensed consolidated financial statements requires the use of estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amount of income and expenses during the period. The Company bases its estimates and assumptions on historical experience and other factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The actual results may differ from these estimates. On an on-going s right-of-use Going concern Since its inception, the Company has primarily funded its operations with equity financings, and, to a lesser extent, public assistance aimed at supporting innovation and payments associated with research tax credits ( Crédit d’Impôt Recherche Following receipt of a Complete Response Letter (“CRL”) from the U.S. Food and Drug Administration (“FDA”) in connection with its BLA for Viaskin ™ pre-clinical ™ ™ Based on the Company’s plans to address the guidance received from the FDA in January 2021 and additional feedback received in October 2021 regarding the protocol for STAMP (Safety, Tolerability and Adhesion of Modified Patches), and its expected cost savings from implementation of the global restructuring plan, the Company expects that its balance of cash and cash equivalents of $98.2 million as of September 30, 2021 will be sufficient to fund its operations into the third quarter of 2022. As of the date of the filing, the Company’s available cash is not projected to be sufficient to support its operating plan for the next 12 months. As such, there is substantial doubt regarding the Company’s ability to continue as a going concern. The Company intends to seek additional capital as it prepares for the launch of Viaskin Peanut, if approved, and continues other research and development efforts. The Company may seek to finance its future cash needs through a combination of public or private equity or debt financings, collaborations, license and development agreements and other forms of non-dilutive The Company cannot guarantee that it will be able to obtain the necessary financing to meet its needs or to obtain funds at attractive terms and conditions, including as a result of disruptions to the global financial markets due to the ongoing COVID-19 COVID-19 If the Company is not successful in its financing objectives, the Company could have to scale back its operations, notably by delaying or reducing the scope of its research and development efforts, or obtain financing through arrangements with collaborators or others that may require the Company to relinquish rights to its product candidates that the Company might otherwise seek to develop or commercialize independently. These interim financial statements have been prepared assuming the Company will continue as a going concern. The going concern assumption contemplates the realization of assets and satisfaction of liabilities in the normal course of business. However, substantial doubt about the Company’s ability to continue as a going concern exists. Accounting Pronouncements adopted in 2021 Effective January 1, 2021, the Company adopted ASU 2019-12, Income 2019-12 Accounting Pronouncements issued not yet adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13—Financial 2019-10 Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s Consolidated Financial Statements upon adoption.

Significant Events and Transact

Significant Events and Transactions	9 Months Ended
	Sep. 30, 2021
Significant Events And Transactions Disclosure [Abstract]
Significant Events and Transactions	Note 2: Significant Events and Transactions Clinical programs Viaskin TM 4-11 In January 2020, the Company announced positive topline results of the three-year, open-label extension of its Phase III PEPITES trial (the “PEOPLE trial”) evaluating the long-term efficacy and safety of investigational Viaskin Peanut in peanut-allergic children ages 4 to 11 years. The results demonstrated long-term clinical benefit as shown by an increase in eliciting dose (“ED”), which may decrease the chance of reacting to an accidental peanut exposure. After three years, the Company observed that 75.9% (107/141) of patients had increased their ED from baseline, and 51.8% (73/141) of patients reached an ED of at least 1,000 mg peanut protein by year three. The safety profile of Viaskin Peanut was consistent with that observed in the clinical program to date in over 1,000 patients. During the PEOPLE trial, the most common adverse events were mild to moderate skin reactions localized to the administration site, and there was no epinephrine use deemed related to treatment. No treatment related serious adverse events were reported. One patient experienced one case of mild anaphylaxis that was determined by the investigator to be possibly related to treatment and resolved without anti-anaphylactic treatment. Treatment compliance remained high throughout the study at a mean of 98% over three years of treatment. Low discontinuations due to adverse events were observed. In February 2020, the FDA announced an Allergenic Products Advisory Committee meeting to be held on May 15, 2020 to discuss the BLA for Viaskin Peanut. On March 16, 2020, the Company announced that the FDA had informed the Company that during its ongoing review of the Company’s BLA for Viaskin Peanut, it had identified questions regarding efficacy, including the impact of patch-site adhesion. Therefore, the Advisory Committee meeting to discuss the BLA originally scheduled on May 15, 2020 was cancelled. In August 2020, the Company announced that the FDA has issued a Complete Response Letter (“CRL”) in which the FDA indicated it could not approve the Viaskin Peanut BLA in its current form. The FDA identified concerns regarding the impact of patch-site adhesion on efficacy and indicated the need for patch modifications, and subsequently a new human factor study. The FDA also indicated that supplementary clinical data would need to be generated to support the modified patch. In addition, the FDA requested additional Chemistry, Manufacturing and Controls (“CMC”) data. The FDA did not raise any safety concerns related to Viaskin Peanut. In January 2021, 6-month, In the second quarter of 2021, the Company completed CHAMP (Comparison of adHesion Among Modified Patches), a trial in healthy adult volunteers to evaluate the adhesion of five modified Viaskin Peanut patches in order to identify the top performers. Based on the adhesion parameters studied, the Company was pleased to learn that all modified Viaskin Peanut patches demonstrated better adhesion performance as compared to the current Viaskin Peanut patch. The Company then selected two modified patches that performed best out of the five modified patches studied for further development. The difference between the two selected patches is their shape—one is circular and the other is rectangular with rounded corners. They are both approximately 50% larger than the current patch but maintain the same structure of the occlusion chamber (i.e., foam ring and backing). The Company also conducted advisory boards with patient caregivers and key opinion leaders to obtain qualitative feedback on the consumer experience with both patches. I n the second quarter of 2021, the Company initiated PREQUAL, a Phase 1 study in healthy adult volunteers to optimize the allergen sample collection methodologies and validate the assays DBV intends to use in EQUAL (EQuivalence in Uptake of ALergen) to demonstrate the protein uptake comparability of the modified patch (mVP) to the reference or current patch (cVP). The Company submitted the protocol for STAMP, the 6-month n its communication, the FDA st ated that guidance is forthcoming on how best to demonstrate the protein uptake comparability of the mVP to the reference or current patch (cVP). The STAMP trial will not be initiated until DBV receives complete feedback from the FDA. Viaskin TM 4-11 In November 2020, the Company announced that its Marketing Authorization Application (“MAA”) for Viaskin Peanut had been validated by the European Medicines Agency (“EMA”). The validation of the MAA confirmed that the submission was sufficiently complete to begin the formal review process for Viaskin Peanut to treat peanut allergies in children ages 4 to 11 years. The Company received the first set of questions from the EMA, during the first quarter of 2021, which were consistent with the Company’s expectations and prefiling conversations with the EMA. The Company did not receive questions about the impact of adhesion on efficacy. The EMA’s Committee for Medicinal Products for Human Use will provide a recommendation to the European Commission (“EC”) on whether to grant a marketing authorization when its review of the Viaskin Peanut MAA is complete. In July 2021, the Company received from the EMA a Day 180 list of outstanding issues. The review of the Viaskin Peanut MAA is progressing according to established EMA processes and ongoing conversations with the EMA. Many of EMA’s Objections and Major Objections have been answered; one Major Objection remained. DBV is preparing its responses to the Day 180 letter and evaluating how to best address the Objections, including the remaining Major Objection which questions the limitations of the data, for example, the clinical relevance and effect size supported by a single pivotal study. Further exchanges with EMA are anticipated. DBV estimates the EMA could issue its decision on potential marketing authorization for Viaskin Peanut in the first quarter of 2022. Viaskin Peanut for children ages 1-3 I n June 2020, the Company announced that in Part A, patients in both treatment arms showed consistent treatment effects after 12 months of therapy, as assessed by a double-blind placebo-controlled food challenge and biomarker results. Part A subjects were not included in Part B and the efficacy analyses from Part A were not statistically powered to demonstrate superiority of either dose versus placebo. These results validate the ongoing investigation of the 250 µg dose in this age group, which is the dose being studied in Part B of the study. Enrollment for Part B of EPITOPE was completed in the first quarter of 202 1. Financing In February 2020, the Company announced the closing of an underwritten global offering of an aggregate of 7,500,000 ordinary shares in (i) a public offering of 4,535,581 ordinary shares in the form of 9,071,162 American Depositary Shares (“ADSs”) in the United States, Canada and certain countries outside Europe at a public offering price of $10.25 per ADS (on the basis of an exchange rate of $1.0999 = €1.00), and (ii) an offering exclusively addressed to qualified investors in Europe (including France) of 2,964,419 ordinary shares at an offering price of €18.63 per ordinary share (together, the “Global Offering”). In March 2020, the Company announced that the underwriters partially exercised their option to purchase 338,687 additional ordinary shares in the form of 677,374 ADSs at an offering price of $10.25 per ADS, before deducting commissions and estimated offering expenses (the “Option”). The Option closed on March 4, 2020. Consequently, following partial exercise of the Option, the total number of ordinary shares sold in the global offering was 7,838,687 ordinary shares, including 4,874,268 ordinary shares in the form of 9,748,536 ADSs, bringing the total gross proceeds from the global offering to $160.7 million and net proceeds of $150.0 million. Restructuring The Company initiated a global restructuring plan in June 2020 to provide operational latitude to progress in the clinical development and regulatory review of investigational Viaskin Peanut in the United States and European Union. The Company expects full implementation of the organization-wide costs reduction measures to be completed in the second half of 2021. The following table summarizes restructuring activities as of September 30, 2021 included in current contingencies and other current liabilities in the statement of financial position: Restructuring Restructuring liability—January 1, 2021 9,387 Amounts paid (7,024 ) Other effect including currency translation effect (238 ) Restructuring liability – September 30, 2021 2,125 of which current contingencies 950 of which other current liabilities 1,175 COVID-19 On March 11, 2020, the World Health Organization declared COVID-19 The Company has assessed the impact of the uncertainties created by the pandemic, such as the duration of the outbreak, the efficacy of vaccines and the evolution of variations strains of COVID-19, COVID-19 Legal Proceedings A class action complaint was filed on January 15, 2019 in the United States District Court for the District of New Jersey, entitled Travis Ito-Stone 2:19-cv-00525. 10b-5 A hearing was held on July 29, 2021 in the U.S. District Court for the District of New Jersey where the Court entered an order granting the Company’s Motion to Dismiss the Second Amended Class Action Complaint without prejudice. As the dismissal was without prejudice, the Plaintiffs repled their case by filing a Third Amended Class Action Complaint on September 30, 2021 in the same Court. The Company believes that the allegations contained in the amended complaint are without merit and will continue to defend the case vigorously. The Company believes this complaint will not have a material adverse effect on the Company’s consolidated financial position, results of operations or liquidity.

Cash and Cash Equivalents

Cash and Cash Equivalents	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Note 3: Cash and Cash Equivalents The following tables summarize the cash and cash equivalents as of September 30, 2021 and December 31, 2020: September 30, December 31, 2021 2020 Cash 33,928 42,341 Cash equivalents 64,267 154,011 Total cash and cash equivalents as reported in the statements of financial position 98,195 196,352 Cash equivalents are immediately convertible into cash at no or insignificant cost, on demand. They are measured using level 1 fair value measurements.

Trade Payables and Other Curren

Trade Payables and Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Trade Payables and Other Current Liabilities	Note 4: Trade Payables and Other Current Liabilities 4.1 Trade Payables No discounting was performed on the trade payables to the extent that the amounts did not present payment terms longer than one year at the end of each fiscal period presented. 4.2 Other Liabilities The following tables summarize the other liabilities as of September 30, 2021 and December 31, 2020: September 30, December 2021 2020 Other current liabilities 12,659 22,926 Other non-current liabilities 4,292 475 Total 16,951 23,402 The following table summarizes the other liabilities by nature as of September 30, 2021 and December 31, 2020: September 30, December 2021 2020 Other current Other non-current Total Total Employee related liabilities 6,748 1,674 8,422 17,136 Deferred income 4,291 2,618 6,909 4,687 Tax liabilities 149 — 149 580 Other debts 1,471 — 1,471 999 Total 12,659 4,292 16,951 23,402 The other current liabilities include debt to employees including employee termination allowance and benefits as part of the restructuring (refer to Note 2, “Significant Events and Transactions of the Period – Restructuring”), bonus accruals, and social welfare and tax agency obligations. Deferred income from the collaboration agreement with Nestlé Health Science amounted to $6.9 million as of September 30, 2021.

Shareholders' equity

Shareholders' equity	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Shareholders' equity	Note 5: Shareholders’ equity The share capital as of September 30, 2021 is set at the sum of €5,501,168.70 ($6,528,543 converted at historical rates). It is divided into 55,011,687 fully authorized, subscribed and paid-up During the nine months ended September 30, 2021, the capital increase of approximately $10,000 is linked to the issuance of an aggregate of 82,500 shares pursuant to the exercise of warrants. Pursuant to the authorization granted by the General Meeting of the Shareholders held on May 19, 2021, the accumulated net losses of DBV Technologies S.A. after appropriation of the net result for the year ended December 31, 2020 have been allocated to additional paid-in

Share-Based Payments

Share-Based Payments	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Payments	Note 6: Share-Based Payments The Board of Directors has been authorized by the General Meeting of the Shareholders to grant restricted stock units (“RSU”), stock options (“SO”), employee warrants ( Bons de Souscription de Parts de Créateur d’Entreprise non-employee Bons de Souscription d’Actions During the nine months ended September 30, 2021, the Company granted 75,600 stock options and 44,900 restricted stock units to employees. There have been no changes in the vesting conditions and method of valuation of the SO and RSU from that disclosed in Note 14 to the consolidated financial statements included in the Annual Report. Stock option fair value assumptions during the nine months ended September 30, 2021 Weighted average share price at grant date in € 9.3 Weighted average expected volatility 90.9% Weighted average risk-free interest rate (0.36)% Weighted average expected term (in years) 6 Dividend yield — Weighted average fair value of stock options in € 6.9 During the nine months ended September 30, 2021, pursuant to the authorization granted by the General Meeting of the Shareholders held on May 19, 2021, the Company offered the directors the opportunity to subscribe for warrants to purchase ordinary shares on May 19, 2021, and on June Cox-Ross Warrant fair value assumptions during the nine months ended September 30, 2021 Weighted average share price at grant date in € 10.75 Weighted average expected volatility 90.0% Weighted average risk-free interest rate (0.53)% Weighted average expected term (in years) 3.21 Dividend yield — Weighted average fair value of warrants in € — The changes in number of BSA/BSPCE/SO/RSU are as follows: Number of outstanding BSA BSPCE SO RSU Balance as of December 31, 2020 218,008 5,500 2,610,510 1,118,745 Granted during the period 39,185 — 75,600 44,900 Forfeited during the period — — (100,400 ) (59,500 ) Exercised/released during the period — (5,500 ) — — Expired during the period (500 ) — — — Balance as of September 30, 2021 256,693 — 2,585,710 1,104,145 Share-based payments expenses reflected in the condensed consolidated statements of operations is as follows: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research & development SO (273 ) (6 ) (952 ) 1,144 RSU (660 ) (102 ) (795 ) (628 ) Sales & marketing SO (60 ) 186 (172 ) 2,063 RSU (27 ) (4 ) (75 ) (12 ) General & administrative SO (439 ) 25 (1,791 ) 609 RSU (92 ) (24 ) (293 ) (211 ) Total share-based compensation (expense) (1,551 ) 74 (4,078 ) 2,965

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2021
Loss Contingency [Abstract]
Contingencies	Note 7: Contingencies The following tables summarize the contingencies as of September 30, 2021 and December 31, 2020: September 30, December 31, 2021 2020 Current contingencies 5,633 5,016 Non-current contingencies 7,629 2,527 Total contingencies 13,262 7,542 The changes in contingencies are as follows: Pension Collaboration Loss at Other Total At January 1, 2021 937 3,956 2,649 7,542 Increases in liabilities 127 7,334 478 7,940 Used liabilities — — (1,601 ) (1,601 ) Reversals of unused liabilities — — — — Net interest related to employee benefits, and unwinding of discount — — — — Actuarial gains and losses on defined-benefit plans 10 — — 10 Other effects including currency translation effect (57 ) (458 ) (113 ) (629 ) At September 30, 2021 1,016 10,832 1,413 13,262 Of which current — 4,220 1,413 5,633 Of which non-current 1,016 6,612 — 7,629 In 2020 and during the first nine months of 2021, the ongoing COVID-19 As of September 30, 2021, the Company recorded its collaboration agreement’s revenue based on its updated measurement of progress of the Phase II clinical trial conducted as part of the agreement. The accrual recorded in the amount of the difference between the Company’s current best estimates of costs yet to be incurred and revenues yet to be recognized for the completion of the Phase II clinical trial has been updated accordingly. Other contingencies are primarily composed of the estimated expenses to be incurred as part of the employee-related costs related to restructuring, as well as estimated cost of refurbishing lease premises (Refer to Note 2, “Significant Events and Transactions—Restructuring”). There have been no significant changes in assumptions for the estimation of the retirement commitments from those disclosed in Note 15 to the consolidated financial statements included in the Annual Report.

Operating Income

Operating Income	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Operating Income	Note 8: Operating income The following table summarizes the operating income during the three and nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research tax credit 1,647 1,815 5,324 7,615 Other operating ( loss (324 ) 2,344 (2,549 ) 4,873 Total 1,323 4,158 2,776 12,488 In 2020 and during the first nine months of 2021, the ongoing COVID-19 m As of September 30, 2021, the Company recorded its collaboration agreement’s revenue based on its updated measurement of progress of the Phase II clinical trial conducted as part of the agreement. The accrual recorded in the amount of the difference between the Company’s current best estimates of costs yet to be incurred and revenues yet to be recognized for the completion of the Phase II clinical trial has been updated accordingly.

Allocation of Personnel Expense

Allocation of Personnel Expenses	9 Months Ended
	Sep. 30, 2021
Operating Expenses [Abstract]
Allocation of Personnel Expenses	Note 9: Allocation of Personnel Expenses The Company had an average of 105 employees during the nine months ended September 30, 2021, in comparison with an average of 291 employees during the nine months ended September 30, 2020. The following table summarizes the allocation of personnel expenses by function during the three and nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development expenses 4,161 5,984 12,272 18,294 Sales and marketing expenses 492 2,154 1,528 4,987 General and administrative expenses 2,583 1,570 9,347 6,628 Restructuring expenses — (231 ) — 6,792 Total personnel expenses 7,236 9,477 23,148 36,701 The following table summarizes the allocation of personnel expenses by nature during the three nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Wages and salaries 3,793 7,021 12,629 33,121 Social security contributions 1,110 933 3,505 5,669 Expenses for pension commitments 286 617 981 1,116 Employer contribution to bonus shares 497 981 1,955 (241 ) Share-based payments 1,551 (74 ) 4,078 (2,965 ) Total 7,236 9,477 23,148 36,701 The decrease in personnel expenses is mainly due to a decreased headcount as a result of the 2020 global restructuring plan.

Commitments

Commitments	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments	Note 10: Commitments There have been no significant changes in other commitments from those disclosed in Note 19 to the consolidated financial statements included in the Annual Report.

Relationships with Related Part

Relationships with Related Parties	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Relationships with Related Parties	Note 11: Relationships with Related Parties The Company’s related parties consist of executive officers, directors and beneficial owners of five percent (5%) or more of any class of our voting securities, including any of their immediate family members and any entity owned or controlled by such persons. As of September 30, 2021, the total amount of remuneration granted to the members of the Board of Directors and Executive Committee has not changed significantly since December 31, 2020. Pursuant to the authorization granted by the General Meeting of the Shareholders held on May 19, 2021, the Company offered its directors the opportunity to subscribe for warrants to purchase ordinary shares on May 19, 2021, and on June 3, 2021, the directors subscribed for warrants to purchase an aggregate Share-Based Payments There were no other new significant related-party transactions during the period nor any change in the nature of the transactions from those described in Note 20 to the consolidated financial statements included in the Annual Report.

Loss Per Share

Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Loss Per Share	Note 12: Loss Per Share Basic loss per share is calculated by dividing the net loss attributable to the shareholders of the Company by the weighted average number of ordinary shares outstanding during the period. As the Company was in a loss position for each of the three and nine month periods ended September 30, 2021 and 2020, the diluted loss per share is equal to basic loss per share because the effects of potentially dilutive shares were anti-dilutive as a result of the Company’s net loss. The ordinary share equivalents at September 30, 2021 and 2020 excluded from the calculation of diluted net loss per share for the three months and nine months ended September 30, 2021 and 2020 (in number of potential shares) are set forth here below: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Non-employee warrants 256,693 225,008 256,693 225,008 Employee warrants — 82,500 — 82,500 Stock options 2,585,710 1,596,512 2,585,710 1,596,512 Restricted stock units 1,104,145 713,345 1,104,145 713,345

Events After The Close Of The P

Events After The Close Of The Period	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Events after the Close of the Period	Note 13: Events after the Close of the Period The Company evaluated subsequent events that occurred after September 30, 2021, through the date the condensed consolidated financial statements were issued after their approval by the Board of Directors on October 26, 2021 and determined that there are no significant events that require adjustments or disclosure in such condensed consolidated financial statements.

The Company (Policies)

The Company (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements of the Company and its wholly-owned subsidiaries are unaudited and have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and are presented in U.S. dollars. The amounts are presented in thousands unless otherwise indicated. All significant intercompany accounts and transactions between the Company and its subsidiaries have been eliminated on consolidation. The unaudited condensed consolidated financial statements presented in this Quarterly Report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted from these interim financial statements. However, these condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of management, necessary to fairly state the results of the interim period. These interim financial results are not necessarily indicative of results to be expected for the full fiscal year ending December 31, 2021, or any other future period.
Use of estimates	Use of estimates The preparation of the Company’s condensed consolidated financial statements requires the use of estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amount of income and expenses during the period. The Company bases its estimates and assumptions on historical experience and other factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The actual results may differ from these estimates. On an on-going s right-of-use
Going concern	Going concern Since its inception, the Company has primarily funded its operations with equity financings, and, to a lesser extent, public assistance aimed at supporting innovation and payments associated with research tax credits ( Crédit d’Impôt Recherche Following receipt of a Complete Response Letter (“CRL”) from the U.S. Food and Drug Administration (“FDA”) in connection with its BLA for Viaskin ™ pre-clinical ™ ™ Based on the Company’s plans to address the guidance received from the FDA in January 2021 and additional feedback received in October 2021 regarding the protocol for STAMP (Safety, Tolerability and Adhesion of Modified Patches), and its expected cost savings from implementation of the global restructuring plan, the Company expects that its balance of cash and cash equivalents of $98.2 million as of September 30, 2021 will be sufficient to fund its operations into the third quarter of 2022. As of the date of the filing, the Company’s available cash is not projected to be sufficient to support its operating plan for the next 12 months. As such, there is substantial doubt regarding the Company’s ability to continue as a going concern. The Company intends to seek additional capital as it prepares for the launch of Viaskin Peanut, if approved, and continues other research and development efforts. The Company may seek to finance its future cash needs through a combination of public or private equity or debt financings, collaborations, license and development agreements and other forms of non-dilutive The Company cannot guarantee that it will be able to obtain the necessary financing to meet its needs or to obtain funds at attractive terms and conditions, including as a result of disruptions to the global financial markets due to the ongoing COVID-19 COVID-19 If the Company is not successful in its financing objectives, the Company could have to scale back its operations, notably by delaying or reducing the scope of its research and development efforts, or obtain financing through arrangements with collaborators or others that may require the Company to relinquish rights to its product candidates that the Company might otherwise seek to develop or commercialize independently. These interim financial statements have been prepared assuming the Company will continue as a going concern. The going concern assumption contemplates the realization of assets and satisfaction of liabilities in the normal course of business. However, substantial doubt about the Company’s ability to continue as a going concern exists.
Accounting Pronouncements adopted in 2021	Accounting Pronouncements adopted in 2021 Effective January 1, 2021, the Company adopted ASU 2019-12, Income 2019-12
Accounting Pronouncements issued not yet adopted	Accounting Pronouncements issued not yet adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13—Financial 2019-10 Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s Consolidated Financial Statements upon adoption.

Significant Events and Transa_2

Significant Events and Transactions (Tables)	9 Months Ended
	Sep. 30, 2021
Significant Events And Transactions Disclosure [Abstract]
Summary of restructuring reserve	The following table summarizes restructuring activities as of September 30, 2021 included in current contingencies and other current liabilities in the statement of financial position: Restructuring Restructuring liability—January 1, 2021 9,387 Amounts paid (7,024 ) Other effect including currency translation effect (238 ) Restructuring liability – September 30, 2021 2,125 of which current contingencies 950 of which other current liabilities 1,175

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
Summary of breakdown of cash and cash equivalents	The following tables summarize the cash and cash equivalents as of September 30, 2021 and December 31, 2020: September 30, December 31, 2021 2020 Cash 33,928 42,341 Cash equivalents 64,267 154,011 Total cash and cash equivalents as reported in the statements of financial position 98,195 196,352

Trade Payables and Other Curr_2

Trade Payables and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Other Liabilities [Abstract]
Summary of Other Liabilities	The following tables summarize the other liabilities as of September 30, 2021 and December 31, 2020: September 30, December 2021 2020 Other current liabilities 12,659 22,926 Other non-current liabilities 4,292 475 Total 16,951 23,402
Summary of Other Liabilities by Nature	The following table summarizes the other liabilities by nature as of September 30, 2021 and December 31, 2020: September 30, December 2021 2020 Other current Other non-current Total Total Employee related liabilities 6,748 1,674 8,422 17,136 Deferred income 4,291 2,618 6,909 4,687 Tax liabilities 149 — 149 580 Other debts 1,471 — 1,471 999 Total 12,659 4,292 16,951 23,402

Share-Based Payments (Tables)

Share-Based Payments (Tables)	9 Months Ended
	Sep. 30, 2021
Summary of Stock Options Valuation Assumptions	There have been no changes in the vesting conditions and method of valuation of the SO and RSU from that disclosed in Note 14 to the consolidated financial statements included in the Annual Report. Stock option fair value assumptions during the nine months ended September 30, 2021 Weighted average share price at grant date in € 9.3 Weighted average expected volatility 90.9% Weighted average risk-free interest rate (0.36)% Weighted average expected term (in years) 6 Dividend yield — Weighted average fair value of stock options in € 6.9
Summary of Fair Value of the Warrants has been Estimated Unsing the Cox-Ross Rubinstein Binomial Option Pricing Model	The fair value of the warrants has been estimated unsing the Cox-Ross Warrant fair value assumptions during the nine months ended September 30, 2021 Weighted average share price at grant date in € 10.75 Weighted average expected volatility 90.0% Weighted average risk-free interest rate (0.53)% Weighted average expected term (in years) 3.21 Dividend yield — Weighted average fair value of warrants in € —
Summary of RSU Activity	The changes in number of BSA/BSPCE/SO/RSU are as follows: Number of outstanding BSA BSPCE SO RSU Balance as of December 31, 2020 218,008 5,500 2,610,510 1,118,745 Granted during the period 39,185 — 75,600 44,900 Forfeited during the period — — (100,400 ) (59,500 ) Exercised/released during the period — (5,500 ) — — Expired during the period (500 ) — — — Balance as of September 30, 2021 256,693 — 2,585,710 1,104,145
Summary of Share-Based Payments Expenses	Share-based payments expenses reflected in the condensed consolidated statements of operations is as follows: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research & development SO (273 ) (6 ) (952 ) 1,144 RSU (660 ) (102 ) (795 ) (628 ) Sales & marketing SO (60 ) 186 (172 ) 2,063 RSU (27 ) (4 ) (75 ) (12 ) General & administrative SO (439 ) 25 (1,791 ) 609 RSU (92 ) (24 ) (293 ) (211 ) Total share-based compensation (expense) (1,551 ) 74 (4,078 ) 2,965

Contingencies (Tables)

Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Loss Contingency [Abstract]
Summary of Current Contingencies and Non-current Contingencies	The following tables summarize the contingencies as of September 30, 2021 and December 31, 2020: September 30, December 31, 2021 2020 Current contingencies 5,633 5,016 Non-current contingencies 7,629 2,527 Total contingencies 13,262 7,542
Summary of Movement in Provisions	The changes in contingencies are as follows: Pension Collaboration Loss at Other Total At January 1, 2021 937 3,956 2,649 7,542 Increases in liabilities 127 7,334 478 7,940 Used liabilities — — (1,601 ) (1,601 ) Reversals of unused liabilities — — — — Net interest related to employee benefits, and unwinding of discount — — — — Actuarial gains and losses on defined-benefit plans 10 — — 10 Other effects including currency translation effect (57 ) (458 ) (113 ) (629 ) At September 30, 2021 1,016 10,832 1,413 13,262 Of which current — 4,220 1,413 5,633 Of which non-current 1,016 6,612 — 7,629

Operating Income (Tables)

Operating Income (Tables)	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Schedule of operating income	The following table summarizes the operating income during the three and nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research tax credit 1,647 1,815 5,324 7,615 Other operating ( loss (324 ) 2,344 (2,549 ) 4,873 Total 1,323 4,158 2,776 12,488

Allocation of Personnel Expen_2

Allocation of Personnel Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Operating Expenses [Abstract]
Summary of Allocation of Personnel Expenses By Function	The following table summarizes the allocation of personnel expenses by function during the three and nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development expenses 4,161 5,984 12,272 18,294 Sales and marketing expenses 492 2,154 1,528 4,987 General and administrative expenses 2,583 1,570 9,347 6,628 Restructuring expenses — (231 ) — 6,792 Total personnel expenses 7,236 9,477 23,148 36,701
Summary of Allocation of Personnel Expenses By Nature	The following table summarizes the allocation of personnel expenses by nature during the three nine months ended September 30, 2021 and 2020: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Wages and salaries 3,793 7,021 12,629 33,121 Social security contributions 1,110 933 3,505 5,669 Expenses for pension commitments 286 617 981 1,116 Employer contribution to bonus shares 497 981 1,955 (241 ) Share-based payments 1,551 (74 ) 4,078 (2,965 ) Total 7,236 9,477 23,148 36,701

Loss Per Share (Tables)

Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share, Basic and Diluted [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	The ordinary share equivalents at September 30, 2021 and 2020 excluded from the calculation of diluted net loss per share for the three months and nine months ended September 30, 2021 and 2020 (in number of potential shares) are set forth here below: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Non-employee warrants 256,693 225,008 256,693 225,008 Employee warrants — 82,500 — 82,500 Stock options 2,585,710 1,596,512 2,585,710 1,596,512 Restricted stock units 1,104,145 713,345 1,104,145 713,345

The Company - Additional Inform

The Company - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Subsidiary or Equity Method Investee [Line Items]
Cash and cash equivalents	$ 98,195	$ 196,352	$ 221,404	$ 193,255

Significant Events and Transa_3

Significant Events and Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands	Mar. 02, 2020$ / sharesshares	Feb. 04, 2020$ / sharesshares	Jan. 31, 2020patients	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)patientsshares	Feb. 04, 2020€ / shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stockholders' Equity Note, Stock Split, Conversion Ratio		1.0999
Proceeds From Issuance Of Common Stock | $								$ 150,000
Stock issued during the period, Value | $				$ 473	$ 42	$ (472)	$ 151,023
Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues								7,838,687
Public Offering [member] | Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		7,500,000						4,874,268
Public Offering [member] | American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues								9,748,536
Public Offering [member] | Outside Europe [Member] | Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		4,535,581
Public Offering [member] | Outside Europe [Member] | American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues		9,071,162
Shares Issued, Price Per Share | $ / shares		$ 10.25
Over-Allotment Option | Common Stock [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues	338,687
Over-Allotment Option | American Depositary Shares
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock Issued During Period, Shares, New Issues	677,374
Shares Issued, Price Per Share | $ / shares	$ 10.25
Global Offering [member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Stock issued during the period, Value | $								$ 160,700
Private Placement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Shares Issued, Price Per Share | € / shares									€ 18.63
Stock Issued During Period, Shares, Issued for Services		2,964,419
ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage Of Patients Increased ED From Baseline			75.90%
Number Of Patients Increased ED From Baseline | patients								107
Number Of Patients | patients								141
Percentage Of Patients Increased ED Of Minimum Thousand Milligram Peanut Protein By Three Year			51.80%					73.00%
Number Of Patients Observed For Safety Profile Till Date | patients			1,000
Treatment Compliance Percentage			98.00%
Clinical Program Trial Period			6 months
Minimum | ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Age Of Child			4 years
Maximum | ViaskinTM Clinical Program For Children Aged Between Four to Eleven [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Age Of Child			11 years

Significant Events and Transa_4

Significant Events and Transactions - Summary of restructuring reserve (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Summary of restructuring reserve
Restructuring liability - January 1, 2021	$ 9,387
Amounts paid	(7,024)
Other effect including currency translation effect	(238)
Restructuring liability – September 30, 2021	2,125
of which current contingencies	950
of which other current liabilities	$ 1,175

Cash and Cash Equivalents - Sum

Cash and Cash Equivalents - Summary of breakdown of cash and cash equivalents (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash	$ 33,928	$ 42,341
Cash equivalents	64,267	154,011
Total cash and cash equivalent as reported in statement of financial position	$ 98,195	$ 196,352	$ 221,404	$ 193,255

Trade Payables and Other Curr_3

Trade Payables and Other Current Liabilities - Additional Information (Detail) $ in Millions	Sep. 30, 2021USD ($)
Nestl Health Science [Member]
Deferred revenues	$ 6.9

Trade Payables and Other Curr_4

Trade Payables and Other Current Liabilities - Summary of Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other Liabilities [Abstract]
Other current liabilities	$ 12,659	$ 22,926
Other non-current liabilities	4,292	475
Total	$ 16,951	$ 23,402

Trade Payables and Other Curr_5

Trade Payables and Other Current Liabilities - Summary of Other Liabilities by Nature (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Other Liabilities, By Nature [Line Items]
Other current liabilities	$ 12,659	$ 22,926
Other non-current liabilities	4,292	475
Total	16,951	23,402
Employee related liabilities [Member]
Schedule Of Other Liabilities, By Nature [Line Items]
Other current liabilities	6,748
Other non-current liabilities	1,674
Total	8,422	17,136
Deferred income [Member]
Schedule Of Other Liabilities, By Nature [Line Items]
Other current liabilities	4,291
Other non-current liabilities	2,618
Total	6,909	4,687
Tax Liabilities [Member]
Schedule Of Other Liabilities, By Nature [Line Items]
Other current liabilities	149
Total	149	580
Other Debts [Member]
Schedule Of Other Liabilities, By Nature [Line Items]
Other current liabilities	1,471
Total	$ 1,471	$ 999

Shareholders' equity - Addition

Shareholders' equity - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)shares	Dec. 31, 2020USD ($)	Dec. 31, 2020EUR (€)	Sep. 30, 2021EUR (€)€ / sharesshares	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Class of Stock [Line Items]
Share capital | $	$ 116,892,000	$ 205,491,000			$ 143,019,000	$ 169,176,000	$ 233,099,000	$ 251,739,000	$ 299,662,000	$ 193,186,000
Warrant [Member]
Class of Stock [Line Items]
Stock Issued During Period, Value, Stock Options Exercised | $	$ 10,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | shares	82,500
Share Capital
Class of Stock [Line Items]
Share capital	$ 6,528,543,000			€ 5,501,168,700
Nominal value | € / shares				€ 0.10
Share capital authorized | shares	55,011,687			55,011,687
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings		$ 797,822,881	€ 695,575,130.36

Share-Based Payments - Summary

Share-Based Payments - Summary of Stock Options Valuation Assumptions (Detail)	9 Months Ended
	Sep. 30, 2021€ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average share price at grant date in €	€ 10.75
Weighted average risk-free interest rate	(0.53%)
Weighted average expected term (in years)	3 years 2 months 15 days
Dividend yield
Weighted average fair value of stock options in €	€ 0
Weighted Average [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average share price at grant date in €	€ 9.3
Weighted average expected volatility	90.90%
Weighted average risk-free interest rate	(0.36%)
Weighted average expected term (in years)	6 years
Weighted average fair value of stock options in €	€ 6.9

Share-Based Payments - Summar_2

Share-Based Payments - Summary of Fair Value of the Warrants has been Estimated Unsing the Cox-Ross Rubinstein Binomial Option Pricing Model (Detail)	9 Months Ended
	Sep. 30, 2021€ / shares
Schedule Of Share Based Payment Award Fair Value Of Warrants Valuation Assumptions [Line Items]
Weighted average share price at grant date in €	€ 10.75
Weighted average expected volatility	90.00%
Weighted average risk-free interest rate	(0.53%)
Weighted average expected term (in years)	3 years 2 months 15 days
Dividend yield
Weighted average fair value of warrants in €	€ 0

Share-Based Payments - Summar_3

Share-Based Payments - Summary of RSU Activity (Detail)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options outstanding, Granted during the period	75,600
Number of stock options outstanding, Beginning Balance	2,610,510
Number of stock options outstanding, Forfeited during the period	(100,400)
Number of stock options outstanding, Ending Balance	2,585,710
BSA Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, Expired during the period | $ / shares	$ (500)
Number of warrants outstanding, Beginning Balance	218,008
Number of stock options outstanding, Granted during the period	39,185
Number of warrants outstanding, Exercised/released during the period	0
Number of warrants outstanding, Ending Balance	256,693
BCE Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of warrants outstanding, Beginning Balance	5,500
Number of warrants outstanding, Exercised/released during the period	(5,500)
Number of warrants outstanding, Ending Balance	0
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSU outstanding, Beginning Balance	1,118,745
Number of RSU outstanding, Granted during the period	44,900
Number of RSU outstanding, Forfeited during the period	(59,500)
Number of RSU outstanding, Ending Balance	1,104,145

Share-Based Payments - Summar_4

Share-Based Payments - Summary of Share-Based Payments Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	$ (1,551)	$ 74	$ (4,078)	$ 2,965
Research & Development expenses [Member] | Employee Stock Option Member
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	(273)	(6)	(952)	1,144
Research & Development expenses [Member] | Restricted Stock Units [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	(660)	(102)	(795)	(628)
Sales & Marketing expenses [Member] | Employee Stock Option Member
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	(60)	186	(172)	2,063
Sales & Marketing expenses [Member] | Restricted Stock Units [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	(27)	(4)	(75)	(12)
General & Administrative expenses [Member] | Employee Stock Option Member
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	(439)	25	(1,791)	609
General & Administrative expenses [Member] | Restricted Stock Units [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based payments	$ (92)	$ (24)	$ (293)	$ (211)

Share-Based Payments - Addition

Share-Based Payments - Additional Information (Detail) - shares	Sep. 03, 2021	May 19, 2021	Sep. 30, 2021
Share-Based Payments [Line iteam]
Number of stock options outstanding, Granted during the period			75,600
Warrants Remaining contractual life		4 years
Director [Member] | Warrant [Member]
Share-Based Payments [Line iteam]
Stock Issued During Period, Shares, Issued for Services	39,185	39,185
Share options [Member] | Employees [Member]
Share-Based Payments [Line iteam]
Number of stock options outstanding, Granted during the period			75,600
Restricted Stock Units [Member]
Share-Based Payments [Line iteam]
Number of RSU outstanding, Granted during the period			44,900
Restricted Stock Units [Member] | Employees [Member]
Share-Based Payments [Line iteam]
Number of RSU outstanding, Granted during the period			44,900

Contingencies - Summary of Curr

Contingencies - Summary of Current Contingencies and Non-current Contingencies (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Liability, Defined Benefit Plan [Abstract]
Current contingencies	$ 5,633	$ 5,016
Non-current contingencies	7,629	2,527
Total contingencies	$ 13,262	$ 7,542

Contingencies - Summary of Move

Contingencies - Summary of Movement in Contingencies (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Contingencies, Beginning balance	$ 7,542
Increases in liabilities	7,940
Used liabilities	(1,601)
Reversals of unused liabilities	0
Net interest related to employee benefits, and unwinding of discount	0
Actuarial gains and losses on defined-benefit plans	10
Other effects including currency translation effect	(629)
Contingencies, Ending balance	13,262
Of which current	5,633	$ 5,016
Of which non-current	7,629	$ 2,527
Pension retirement obligations [Member]
Contingencies, Beginning balance	937
Increases in liabilities	127
Actuarial gains and losses on defined-benefit plans	10
Other effects including currency translation effect	(57)
Contingencies, Ending balance	1,016
Of which non-current	1,016
Collaboration agreement -Loss at completion [Member]
Contingencies, Beginning balance	3,956
Increases in liabilities	7,334
Used liabilities	0
Other effects including currency translation effect	(458)
Contingencies, Ending balance	10,832
Of which current	4,220
Of which non-current	6,612
Other provisions incl. restructuring [Member]
Contingencies, Beginning balance	2,649
Increases in liabilities	478
Used liabilities	(1,601)
Other effects including currency translation effect	(113)
Contingencies, Ending balance	1,413
Of which current	$ 1,413

Operating Income - Summary of O

Operating Income - Summary of Operating Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Research Tax Credit	$ 1,647	$ 1,815	$ 5,324	$ 7,615
Other Operating (loss) income	(324)	2,344	(2,549)	4,873
Total	$ 1,323	$ 4,158	$ 2,776	$ 12,488

Allocation of Personnel Expen_3

Allocation of Personnel Expenses - Summary of Allocation of Personnel Expenses By Function (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Research and development expenses	$ 16,320	$ 25,751	$ 58,663	$ 75,214
Sales and marketing expenses	1,072	1,595	2,999	8,114
General and administrative expenses	8,299	6,863	26,250	26,838
Restructuring expenses		(286)		21,003
Total Operating expenses	25,691	33,923	87,912	131,169
Expenses by Function [Member]
Research and development expenses	4,161	5,984	12,272	18,294
Sales and marketing expenses	492	2,154	1,528	4,987
General and administrative expenses	2,583	1,570	9,347	6,628
Restructuring expenses	0	(231)	0	6,792
Total Operating expenses	$ 7,236	$ 9,477	$ 23,148	$ 36,701

Allocation of Personnel Expen_4

Allocation of Personnel Expenses -Summary of Allocation of Personnel Expenses By Nature (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based payments	$ (1,551)	$ 74	$ (4,078)	$ 2,965
Total Operating expenses	25,691	33,923	87,912	131,169
Expenses by Nature [Member]
Wages and salaries	3,793	7,021	12,629	33,121
Social security contributions	1,110	933	3,505	5,669
Expenses for pension commitments	286	617	981	1,116
Employer contribution to bonus shares	497	981	1,955	(241)
Share-based payments	1,551	(74)	4,078	(2,965)
Total Operating expenses	$ 7,236	$ 9,477	$ 23,148	$ 36,701

Commitments - Additional Inform

Commitments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)
Disclosure Of Commitments [Line Items]
Increase (decrease) in other commitments during the period	$ 0

Relationships with Related Pa_2

Relationships with Related Parties - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 03, 2021	May 19, 2021	Sep. 30, 2021
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Increase decrease in related party transactions and changes in nature of the transactions			$ 0
Director [Member] | Warrant [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Stock Issued During Period, Shares, Issued for Services	39,185	39,185

Loss Per Share - Summary of the

Loss Per Share - Summary of the Common Stock Equivalents Which Were Excluded From the Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Non-employee warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	256,693	225,008	256,693	225,008
Employee warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	82,500	0	82,500
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,585,710	1,596,512	2,585,710	1,596,512
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,104,145	713,345	1,104,145	713,345