Gelesis (GLSHQ) 10-Q 14 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 11, 2022
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2022
Entity File Number	001-39362
Entity Registrant Name	Gelesis Holdings, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4730610
Entity Address, Address Line One	501 Boylston Street
Entity Address, Address Line Two	Suite 6102
Entity Address, City or Town	Boston
Entity Address State Or Province	MA
Entity Address, Postal Zip Code	02116
City Area Code	617
Local Phone Number	456-4718
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001805087
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		73,033,504
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	GLS
Security Exchange Name	NYSE
Redeemable Warrants
Document Information [Line Items]
Title of 12(b) Security	Redeemable warrants, each whole warrant exercisable for one share of Common Stock at an exercise price of $11.50
Trading Symbol	GLS WS
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 24,847	$ 28,397
Accounts receivable	775	731
Grants receivable	4,789	9,172
Inventories	18,411	13,503
Prepaid expenses and other current assets	5,876	14,203
Total current assets	54,698	66,006
Property and equipment, net	55,152	58,515
Operating lease right-of-use assets	1,627	2,016
Intangible assets, net	13,980	15,680
Other assets	5,060	4,084
Total assets	130,517	146,301
Current liabilities:
Accounts payable, including due to related party of $458 and $147, respectively	7,969	10,066
Accrued expenses and other current liabilities, including due to related party of $2,540 and $5,664 respectively	12,256	13,660
Deferred income	28,895	32,370
Operating lease liabilities	578	541
Convertible promissory notes held at fair value, including due to related party of $20,852 and $27,128, respectively	25,852	27,128
Notes payable	4,249	1,950
Warrant liabilities		15,821
Total current liabilities	79,799	101,536
Deferred income	8,150	8,914
Operating lease liabilities	1,095	1,519
Notes payable, including due to related party of $14,273 and $16,523, respectively	26,716	35,131
Warrant liabilities	590
Earnout liability	3,376
Other long-term liabilities, including due to related party of $1,244 and $2,416, respectively	3,912	5,588
Total liabilities	123,638	152,688
Commitments and contingencies (Note 19)
Noncontrolling interest	10,474	11,855
Stockholders' deficit:
Preferred stock, $0.0001 par value - 250,000,000 shares authorized at September 30, 2022; zero shares issued and outstanding at September 30, 2022 and December 31, 2021
Common stock, $0.0001 par value - 900,000,000 shares authorized at September 30, 2022; 72,983,488 shares issued and outstanding at September 30, 2022; 125,961,571 shares authorized at December 31, 2021; 6,248,192 shares issued and outstanding at December 31, 2021	7	1
Additional paid-in capital	295,333	(64,549)
Accumulated other comprehensive (loss) income	(810)	219
Accumulated deficit	(298,125)	(265,507)
Total stockholders' deficit	(3,595)	(329,836)
Total liabilities, noncontrolling interest, redeemable convertible preferred stock and stockholders' deficit	$ 130,517	146,301
Legacy Gelesis Redeemable Convertible Preferred Stock
Current liabilities:
Legacy Gelesis redeemable convertible preferred stock, $0.0001 par value - zero shares issued and outstanding at September 30, 2022; 51,730,762 shares authorized at December 31, 2021; and 48,566,655 shares issued and outstanding at December 31, 2021		$ 311,594

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accounts payable, due to related party	$ 458	$ 147
Accrued expenses and other liabilities, due to related parties	2,540	5,664
Convertible promissory note due to related party	20,852	27,128
Notes payable, due to related party	14,273	16,523
Other long-term liabilities noncurrent, due to related party	$ 1,244	$ 2,416
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	900,000,000	125,961,571
Common stock, shares issued	72,983,488	6,248,192
Common stock, shares outstanding	72,983,488	6,248,192
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	250,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Legacy Gelesis Redeemable Convertible Preferred Stock
Temporary equity, par value	$ 0.0001	$ 0.0001
Temporary equity, shares authorized		51,730,762
Temporary equity, shares issued	0	48,566,655
Temporary equity, shares outstanding	0	48,566,655

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total revenue, net	$ 6,652	$ 3,014	$ 23,139	$ 8,293
Operating expenses:
Costs of goods sold, including related party expenses of $266 and $121, respectively, and $926 and $332, respectively	3,616	2,763	13,315	7,584
Selling, general and administrative, including related party expenses of $126 and $124, respectively, and $376 and $369, respectively	17,032	24,725	87,188	50,642
Research and development, including related party expenses of $44 and $52, respectively, and $163 and $182, respectively	3,365	3,238	16,298	13,206
Amortization of intangible assets	567	567	1,700	1,700
Total operating expenses	24,580	31,293	118,501	73,132
Loss from operations	(17,928)	(28,279)	(95,362)	(64,839)
Change in the fair value of earnout liability	2,814		55,495
Change in the fair value of convertible promissory notes	(852)		(1,008)
Change in the fair value of warrants	540	(2,231)	6,624	(9,282)
Interest expense, net	(164)	(361)	(485)	(949)
Other income, net	1,441	141	2,371	1,032
Loss before income taxes	(14,149)	(30,730)	(32,365)	(74,038)
Provision for income taxes	0	0	0	17
Net loss	(14,149)	(30,730)	(32,365)	(74,055)
Accretion of Legacy Gelesis senior preferred stock to redemption value		(23,111)	(37,934)	(139,237)
Accretion of noncontrolling interest put option to redemption value	(80)	(95)	(253)	(285)
Net loss attributable to common stockholders	$ (14,229)	$ (53,936)	$ (70,552)	$ (213,577)
Net loss per share attributable to common stockholders - basic and diluted	$ (0.20)	$ (9.61)	$ (1.02)	$ (38.19)
Weighted average common shares outstanding - basic and diluted	72,772,627	5,615,192	69,349,679	5,592,931
Product Revenue, Net
Revenue:
Total revenue, net	$ 6,443	$ 3,014	$ 22,930	$ 8,293
Licensing Revenue
Revenue:
Total revenue, net	$ 209		$ 209

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (PARENTHETICAL) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Cost of goods sold, related party expense	$ 266	$ 121	$ 926	$ 332
Selling, general and administrative, related party expense	126	124	376	369
Research and development, related party expense	$ 44	$ 52	$ 163	$ 182

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (14,149)	$ (30,730)	$ (32,365)	$ (74,055)
Other comprehensive (loss) income:
Foreign currency translation adjustment	(466)	(198)	(1,029)	(566)
Total other comprehensive (loss) income	(466)	(198)	(1,029)	(566)
Comprehensive loss	$ (14,615)	$ (30,928)	$ (33,394)	$ (74,621)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF NONCONTROLLING INTEREST, REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' DEFICIT - USD ($) $ in Thousands	Total	Previously Reported	Legacy Gelesis Redeemable Convertible Preferred Stock	Legacy Gelesis Redeemable Convertible Preferred Stock Previously Reported	Legacy Gelesis Redeemable Convertible Preferred Stock Retroactive Application of Recapitalization	Series A-3 Redeemable Convertible Preferred Stock	Common Stock Commitment Shares	Noncontrolling Interest	Noncontrolling Interest Previously Reported	Common Stock	Common Stock Previously Reported	Common Stock Retroactive Application of Recapitalization	Common Stock Common Stock Commitment Shares	Additional Paid-in Capital	Additional Paid-in Capital Previously Reported	Additional Paid-in Capital Common Stock Commitment Shares	Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income Previously Reported	Accumulated Deficit	Accumulated Deficit Previously Reported
Balance at Dec. 31, 2020	$ (146,938)	$ (146,938)								$ 1	$ 1			$ 23,907	$ 23,907		$ 938	$ 938	$ (171,784)	$ (171,784)
Temporary Equity Balance at Dec. 31, 2020			$ 213,525	$ 213,525				$ 12,429	$ 12,429
Temporary Equity Balance, shares at Dec. 31, 2020			47,813,946	18,446,525	29,367,421
Balance, shares at Dec. 31, 2020										5,587,094	2,155,490	3,431,604
Accretion of Legacy Gelesis senior preferred stock to redemption value	(33,761)													(33,761)
Temporary Equity, Accretion of Legacy Gelesis senior preferred stock to redemption value			$ 33,761
Temporary Equity, Exercise of Legacy Gelesis preferred stock warrants						$ 2,997
Temporary Equity, Exercise of Legacy Gelesis preferred stock warrants, shares						752,709
Stock based compensation expense	1,455													1,455
Issuance of common stock upon exercise of stock options	4													4
Issuance of common stock upon exercise of stock options shares										2,634
Accretion of noncontrolling interest put option to redemption value	(94)																		(94)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								94
Foreign currency translation adjustment	(411)																(411)
Temporary Equity, Foreign currency translation adjustment								(546)
Net loss	(18,586)																		(18,586)
Balance at Mar. 31, 2021	(198,331)									$ 1				(8,395)			527		(190,464)
Temporary Equity Balance at Mar. 31, 2021				$ 250,283				11,977
Temporary Equity Balance, shares at Mar. 31, 2021			48,566,655
Balance, shares at Mar. 31, 2021										5,589,728
Balance at Dec. 31, 2020	(146,938)	(146,938)								$ 1	$ 1			23,907	23,907		938	938	(171,784)	(171,784)
Temporary Equity Balance at Dec. 31, 2020			$ 213,525	$ 213,525				12,429	12,429
Temporary Equity Balance, shares at Dec. 31, 2020			47,813,946	18,446,525	29,367,421
Balance, shares at Dec. 31, 2020										5,587,094	2,155,490	3,431,604
Net loss	(74,055)
Balance at Sep. 30, 2021	(356,892)									$ 1				(111,141)			372		(246,124)
Temporary Equity Balance at Sep. 30, 2021			$ 356,696					12,021
Temporary Equity Balance, shares at Sep. 30, 2021			48,566,655
Balance, shares at Sep. 30, 2021										5,615,192
Balance at Mar. 31, 2021	(198,331)									$ 1				(8,395)			527		(190,464)
Temporary Equity Balance at Mar. 31, 2021				$ 250,283				11,977
Temporary Equity Balance, shares at Mar. 31, 2021			48,566,655
Balance, shares at Mar. 31, 2021										5,589,728
Accretion of Legacy Gelesis senior preferred stock to redemption value	(82,365)													(82,365)
Temporary Equity, Accretion of Legacy Gelesis senior preferred stock to redemption value			$ 82,365
Temporary Equity, Exercise of Legacy Gelesis preferred stock warrants			$ 937
Stock based compensation expense	1,639													1,639
Issuance of common stock upon exercise of stock options	5													5
Issuance of common stock upon exercise of stock options shares										25,464
Accretion of noncontrolling interest put option to redemption value	(96)																		(96)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								96
Foreign currency translation adjustment	43																43
Temporary Equity, Foreign currency translation adjustment								152
Net loss	(24,739)																		(24,739)
Balance at Jun. 30, 2021	(303,844)									$ 1				(89,116)			570		(215,299)
Temporary Equity Balance at Jun. 30, 2021				333,585				12,225
Temporary Equity Balance, shares at Jun. 30, 2021			48,566,655
Balance, shares at Jun. 30, 2021										5,615,192
Accretion of Legacy Gelesis senior preferred stock to redemption value	(23,111)													(23,111)
Temporary Equity, Accretion of Legacy Gelesis senior preferred stock to redemption value			$ 23,111
Stock based compensation expense	1,086													1,086
Accretion of noncontrolling interest put option to redemption value	(95)																		(95)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								95
Foreign currency translation adjustment	(198)																(198)
Temporary Equity, Foreign currency translation adjustment								(299)
Net loss	(30,730)																		(30,730)
Balance at Sep. 30, 2021	(356,892)									$ 1				(111,141)			372		(246,124)
Temporary Equity Balance at Sep. 30, 2021			$ 356,696					12,021
Temporary Equity Balance, shares at Sep. 30, 2021			48,566,655
Balance, shares at Sep. 30, 2021										5,615,192
Balance at Dec. 31, 2021	(329,836)	(329,836)								$ 1	$ 1			(64,549)	(64,549)		219	219	(265,507)	(265,507)
Temporary Equity Balance at Dec. 31, 2021			$ 311,594	$ 311,594				11,855	11,855
Temporary Equity Balance, shares at Dec. 31, 2021			48,566,655	18,736,936	29,829,719
Balance, shares at Dec. 31, 2021										6,248,192	2,410,552	3,837,640
Accretion of legacy gelesis senior preferred stock to redemption value prior to business combination	(37,934)													(37,934)
Temporary Equity, Accretion of legacy gelesis senior preferred stock to redemption value prior to business combination			$ 37,934
Conversion of legacy gelesis convertible preferred stock into common stock upon business combination	349,528													349,528
Conversion of legacy gelesis convertible preferred stock into common stock upon business combination, shares										48,566,655
Temporary Equity, Conversion of legacy gelesis convertible preferred stock into common stock upon business combination			$ (349,528)
Temporary Equity, Conversion of legacy gelesis convertible preferred stock into common stock upon business combination, shares			(48,566,655)
Proceeds from business combination, net of issuance costs and assumed liabilities	70,478									$ 6				70,472
Proceeds from business combination, net of issuance costs and assumed liabilities, shares										17,399,440
Conversion of legacy gelesis preferred stock warrants into common stock warrants upon business combination	16,747													16,747
Recognition of earnout liability upon Business Combination	(58,871)													(58,871)
Assumed private placement warrant liability upon business combination	(8,140)													(8,140)
Exercise of warrants	4													4
Exercise of warrants, shares										176,126
Stock based compensation expense	13,989													13,989
Accretion of noncontrolling interest put option to redemption value	(88)																		(88)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								88
Foreign currency translation adjustment	(137)																(137)
Temporary Equity, Foreign currency translation adjustment								(239)
Net loss	(5,703)																		(5,703)
Balance at Mar. 31, 2022	10,037									$ 7				281,246			82		(271,298)
Temporary Equity Balance at Mar. 31, 2022								11,704
Balance, shares at Mar. 31, 2022										72,390,413
Balance at Dec. 31, 2021	$ (329,836)	$ (329,836)								$ 1	$ 1			(64,549)	$ (64,549)		219	$ 219	(265,507)	$ (265,507)
Temporary Equity Balance at Dec. 31, 2021			$ 311,594	$ 311,594				11,855	$ 11,855
Temporary Equity Balance, shares at Dec. 31, 2021			48,566,655	18,736,936	29,829,719
Balance, shares at Dec. 31, 2021										6,248,192	2,410,552	3,837,640
Issuance of common stock upon exercise of stock options shares	162,064
Net loss	$ (32,365)
Balance at Sep. 30, 2022	(3,595)									$ 7				295,333			(810)		(298,125)
Temporary Equity Balance at Sep. 30, 2022								10,474
Temporary Equity Balance, shares at Sep. 30, 2022			0
Balance, shares at Sep. 30, 2022										72,983,488
Balance at Mar. 31, 2022	10,037									$ 7				281,246			82		(271,298)
Temporary Equity Balance at Mar. 31, 2022								11,704
Balance, shares at Mar. 31, 2022										72,390,413
Stock based compensation expense	7,976													7,976
Issuance of common stock upon exercise of stock options	110													110
Issuance of common stock upon exercise of stock options shares										162,064
Accretion of noncontrolling interest put option to redemption value	(85)																		(85)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								85
Foreign currency translation adjustment	(426)																(426)
Temporary Equity, Foreign currency translation adjustment								(702)
Net loss	(12,513)																		(12,513)
Balance at Jun. 30, 2022	5,099									$ 7				289,332			(344)		(283,896)
Temporary Equity Balance at Jun. 30, 2022								11,087
Balance, shares at Jun. 30, 2022										72,552,477
Stock based compensation expense	4,574													4,574
Release of restricted stock units, shares										41,404
Issuance of common stock							$ 500									$ 500
Issuance of common stock, shares													355,361
Sale of common stock, net of commissions	37													37
Sale of common stock net of commissions, shares										34,246
Issuance of common stock warrants	890													890
Accretion of noncontrolling interest put option to redemption value	(80)																		(80)
Temporary Equity, Accretion of noncontrolling interest put option to redemption value								80
Foreign currency translation adjustment	(466)																(466)
Temporary Equity, Foreign currency translation adjustment								(693)
Net loss	(14,149)																		(14,149)
Balance at Sep. 30, 2022	$ (3,595)									$ 7				$ 295,333			$ (810)		$ (298,125)
Temporary Equity Balance at Sep. 30, 2022								$ 10,474
Temporary Equity Balance, shares at Sep. 30, 2022			0
Balance, shares at Sep. 30, 2022										72,983,488

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash flows from operating activities:
Net loss			$ (32,365)	$ (74,055)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of intangible assets	$ 567	$ 567	1,700	1,700
Reduction in carrying amount of right-of-use assets			343	133
Depreciation	300	200	2,133	591
Stock-based compensation			26,539	4,180
Issuance of common stock commitment shares			500
Gain on sales of common stock			(1)
Unrealized loss (gain) on foreign currency transactions			1,305	132
Non-cash interest (income) expense			(29)	65
Gain on CMS Amendment			(209)
Loss on One S.r.l. amendment			278
Accretion on marketable securities			0	(1)
Change in the fair value of earnout liability			(55,495)
Change in the fair value of warrants	(540)	2,231	(6,624)	9,282
Change in the fair value of convertible promissory notes			1,008
Change in fair value of One S.r.l. call option			(808)	601
Change in fair value of interest rate swap contract			(758)	95
Changes in operating assets and liabilities:
Account receivables			(745)	618
Grants receivable			3,407	(1,145)
Prepaid expenses and other current assets			5,246	(5,981)
Inventories			(4,928)	(4,470)
Other assets			229	(5,137)
Accounts payable			(1,758)	3,278
Accrued expenses and other current liabilities			2,742	16,161
Operating lease liabilities			(341)	(123)
Deferred income			(2,799)	34,542
Other long-term liabilities			(23)	(6,861)
Net cash used in operating activities			(61,453)	(26,395)
Cash flows from investing activities:
Purchases of property and equipment			(8,473)	(18,383)
Maturities of marketable securities				24,000
Net cash (used in) provided by investing activities			(8,473)	5,617
Cash flows from financing activities:
Proceeds from Business Combination, net of transaction costs			70,479
Principal repayment of notes payable			(1,342)	(226)
Repayment of convertible promissory notes			(27,284)
Proceeds from convertible promissory notes			25,000
Proceeds from issuance of promissory notes (net of issuance costs of $0 and $30, respectively)				5,679
Proceeds from the exercise of warrants			4	10
Proceeds from exercise of share-based awards			110	9
Proceeds from sales of common stock, net of issuance costs			39
Net cash provided by financing activities			67,006	5,472
Effect of exchange rates on cash			(630)	(816)
Net decrease in cash			(3,550)	(16,122)
Cash and cash equivalents at beginning of year			28,397	48,144	$ 48,144
Cash and cash equivalents at end of period	$ 24,847	$ 32,022	24,847	32,022	$ 28,397
Noncash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expense			958	2,086
Deferred financing costs included in accounts payable and accrued expense				564
Recognition of earnout liability			58,871
Recognition of private placement warrant liability			8,140
Acquisitions of right-of-use assets under operating leases			101	190
Supplemental cash flow information:
Interest paid on notes payable			$ 233	$ 199

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (PARENTHETICAL) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Statement Of Cash Flows [Abstract]
Payment of issuance costs	$ 0	$ 207

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Nature of Business Gelesis Holdings, Inc., or the Company, formerly known as Capstar Special Purpose Acquisition Corp. or “CPSR ” , is a commercial stage biotherapeutics company incorporated under the laws of the State of Delaware. The Company aims to transform weight management through proprietary biomimetic hydrogel technology, inspired by the compositional and mechanical properties of raw vegetables. Since its inception, the Company has devoted substantially all of its efforts to business planning, licensing technology, research and development, commercial activities, recruiting management and technical staff and raising capital and has financed its operations through the issuance of redeemable convertible preferred and common stock, a license and collaboration agreement, supply and distribution agreements, long-term loans, convertible bridge note financings, and government grants. The Company currently manufactures and markets its first product, Plenity® (the “ Product ” ), which is based on a proprietary hydrogel technology. Plenity® received de novo clearance from the FDA on April 12, 2019 as a Class II medical device to aid in weight management in adults with excess weight or obesity, Body Mass Index (BMI) of 25 to 40 kg/m 2 , when used in conjunction with diet and exercise. In June 2019, the Company received approval to market Plenity in Europe through a Conformité Européenne (CE) mark for Plenity as a Class III medical device indicated for weight loss in overweight and obese adults with a Body Mass Index (BMI) of 25-40 kg/m 2 , when used in conjunction with diet and exercise. Plenity, which is available by prescription in the United States, became available for first commercial sale in May 2020 to a limited number of consumers. In October 2020, availability was increased to test commercial interest and consumer experience. Activities associated with a full commercial launch of Plenity in the United States began in late 2021, and in February 2022, the Company launched the first national broad awareness media campaign for the product. On July 19, 2021, Gelesis, Inc. (together with its consolidated subsidiaries, “Legacy Gelesis”) entered into a Business Combination Agreement (as amended on November 8, 2021 and December 30, 2021, the “Business Combination Agreement”) with CPSR, a Delaware corporation and special purpose acquisition company, and CPSR Gelesis Merger Sub, Inc., a Delaware corporation and wholly-owned subsidiary of CPSR (“Merger Sub”). On January 13, 2022, Legacy Gelesis, CPSR, and Merger Sub consummated the business combination (“Business Combination”) pursuant to the terms of the Business Combination Agreement. Pursuant to the Business Combination Agreement, on the closing date, (i) Merger Sub merged with and into Legacy Gelesis (the “Merger”), with Legacy Gelesis as the surviving company in the Merger, and, after giving effect to such Merger, Legacy Gelesis became a wholly-owned subsidiary of CPSR and (ii) CPSR changed its name to “Gelesis Holdings, Inc.” (together with its consolidated subsidiaries, “Gelesis Holdings”). The Business Combination, together with the PIPE Investment and the sale of the Backstop Purchase Shares, generated approximately $ 105 million in gross proceeds and $ 70.5 million in net proceeds (See Note 3). On January 14, 2022, Gelesis Holdings’ common stock and public warrants began trading on the New York Stock Exchange ("NYSE") under the symbols “GLS” and “GLS.W”, respectively. The Business Combination was accounted for as a reverse recapitalization in conformity with accounting principles generally accepted in the United States. Under this method of accounting, CPSR has been treated as the "acquired" company for financial reporting purposes. This determination was primarily based on the Legacy Gelesis’ stockholders comprising a relative majority of the voting power of the combined company, the Legacy Gelesis’ operations prior to the acquisition comprising the only ongoing operations of Gelesis Holdings, the majority of Gelesis Holdings’ board of directors appointment by Legacy Gelesis, and Legacy Gelesis’ senior management comprising the entirety of the senior management of Gelesis Holdings. Accordingly, for accounting purposes, the consolidated financial statements of Gelesis Holdings will represent a continuation of the consolidated financial statements of Legacy Gelesis with the Business Combination being treated as the equivalent of Legacy Gelesis issuing stock for the net assets of CPSR, accompanied by a recapitalization. The net assets of CPSR will be stated at historical costs, with no goodwill or other intangible assets recorded. Going Concern The unaudited condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the ordinary course of business. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded assets and liabilities that might be necessary should the Company be unable to continue as a going concern. The Company has a history of incurring substantial operating losses and has financed its operations primarily from the issuance of equity, promissory notes, government grants, supply and distribution agreements and collaborations and licensing arrangements. Such operating losses and negative cash flows from operations have continued in the first three quarters of 2022 and the Company expects they will continue in the foreseeable future. Even with proceeds from the Business Combination, the aggregate proceeds from the issuance of convertible promissory notes and the CMS amendment, the Company expects its cash on hand as of the date of the condensed consolidated financial statements and collection of accounts and grants receivable will only be sufficient to meet the Company’s obligations into the second quarter of 2023, and not at least twelve months beyond the date of issuance of the condensed consolidated financial statements. However, the extension of the Company's cash runway into the second quarter of 2023 is only achievable with the significant reduction of discretionary spending from prior levels, particularly with respect to the Company's discretionary sales and marketing activities and manufacturing and supply chain functions, and prior to considerations for any additional funding. These conditions raise substantial doubt about the Company’s ability to continue as a going concern and may adversely impact the sale of Plenity. The Company will need to raise additional capital in future periods to fund its operations. The Company will seek to raise necessary funds through a combination of equity issuances, debt financings, strategic collaborations and licensing arrangements, government grants, or other financing mechanisms. The Company’s ability to fund the completion of its ongoing and planned clinical studies, as well as its regulatory and commercial efforts, may be substantially dependent upon whether the Company can obtain sufficient funding at acceptable terms. If adequate sources of funding are not available to the Company, the Company may be required to delay, reduce or eliminate research and development programs, reduce or eliminate commercialization efforts, and reduce its headcount. Additionally, the Company is subject to risks common to companies in the biotechnology industry, including but not limited to, risks of failure of the full-scope product commercialization in targeted markets, clinical trials and preclinical studies, the impact of the COVID-19 pandemic on the Company’s supply chain and results of operations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, and development by competitors of technological innovations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company’s condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) issued by the Financial Accounting Standards Board (“FASB”). The Company consolidates those entities where it has a direct and indirect controlling financial interest based on either a variable interest model or voting interest model. The Company’s condensed consolidated financial statements include the accounts of the Company, its two wholly-owned subsidiaries and a variable interest entity (“VIE”), Gelesis S.r.l., in which the Company has a controlling interest and is the primary beneficiary. The noncontrolling interest attributable to the Company’s VIE is presented as a separate component from stockholders’ deficit in the condensed consolidated balance sheets and as a noncontrolling interest in the condensed consolidated statements of noncontrolling interest, redeemable convertible preferred stock and stockholders’ deficit. All intercompany balances and transactions have been eliminated in consolidation. Under the variable interest model, a controlling financial interest is determined based on which entity, if any, has (i) the power to direct the activities of the VIE that most significantly impacts the VIE’s economic performance and (ii) the obligations to absorb losses that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. Management performs ongoing reassessments of whether changes in the facts and circumstances regarding the Company’s involvement with a VIE will cause the consolidation conclusion to change. The consolidation status of a VIE may change as a result of such reassessments. Changes in consolidation status are applied prospectively in accordance with U.S. GAAP. Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no effect on the reported results of operations or financial position. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. The Company assesses the above estimates on an ongoing basis; however, actual results could materially differ from those estimates. Subsequent Event(s) The Company considers events or transactions that occur after the balance sheet date but before the condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The Company evaluated all events and transactions through the date these condensed consolidated financial statements were filed with the Securities and Exchange Commission (“SEC”) or were available to be issued. Fair Value of Financial Instruments The guidance in FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”), defines fair value and establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 – Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Fair value is a market-based measure considered from the perspective of a market participant rather than an entity-specific measure. Therefore, even when market assumptions are not readily available, the Company’s own assumptions are set to reflect those that market participants would use in pricing the asset or liability at the measurement date. The Company uses prices and inputs that are current as of the measurement date, including during periods of market dislocation. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from Level 1 to Level 2 or Level 2 to Level 3. The Company’s earnout liability, private placement warrants, and call option liability are recorded at fair value on a recurring basis. The carrying amount of accounts receivable, grants receivable, accounts payable and accrued expenses are considered a reasonable estimate of their fair value, due to the short-term maturity of these instruments. The carrying amount of notes payable is also considered to be a reasonable estimate of the fair value based on the nature of the debt and that the debt bears interest at the prevailing market rate for instruments with similar characteristics. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above. Earnout Liability: In connection with the Business Combination, Legacy Gelesis Equityholders received the right to receive additional common stock upon the achievement of certain earnout targets. As the earnout consideration contains a settlement provision that precludes it from being indexed to the Company’s stock, it is classified as a liability held at fair value in accordance ASC 815 and the instrument is adjusted to fair value at each reporting period. In determining the fair value of the earnout liability at inception and on a recurring basis, the Company utilizes the Monte Carlo simulation value model where the fair value of the earnout is the present value of a distribution of potential outcomes on a daily basis over the term of the earnout period. Private Placement Warrant Liability: The Private Placement Warrants are recognized as liabilities in accordance with ASC 815. Accordingly, the Company recognizes the warrant instruments as liabilities held at fair value and adjusts the instruments to fair value at each reporting period. In determining the fair value of the Private Placement Warrant liability, the Company utilized a modified Monte Carlo simulation value model at inception and on a recurring basis. One S.r.l. Call Option: In connection with the October 2020 amended agreement with One S.r.l., the Company granted One a contingent call option to buy back the 10 % ownership that the Company acquired in the 2019 One Amendment. The One S.r.l. call option was recorded as a liability held at fair value at the date of issuance and is remeasured at each subsequent reporting date with changes in fair value recorded in other income (expense) in the accompanying condensed consolidated statements of operations. Fair value is determined using a Black-Scholes option pricing model. Convertible promissory notes: The convertible promissory notes issued in conjunction with the Company’s bridge financing arrangements from time to time were recognized at fair value at issuance and subsequent changes in fair value were recorded in the accompanying consolidated statements of operations (see Note 12). Fair value of the promissory notes is determined using a multiple scenario-based valuation method. The fair value of the hybrid instrument was determined by calculating the value of the instrument in each scenario “with” the respective conversion feature and “without”. The significant inputs used in estimating the fair value of the convertible promissory notes include the estimated discount rate, expected term, and the outcome probability with respect to each scenario. Revenue Recognition Product Revenue The Company commercializes Plenity in the U.S. markets principally through synergistic partnerships with online pharmacies and telehealth providers, which in turn sell Plenity directly to patients based on prescriptions. Outside the U.S., the Company primarily seeks collaborations with strategic partners to market Plenity and obtain necessary regulatory approvals as necessary. Product revenue is recognized by the Company in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services when the customer obtains control of the product, which occurs at a point in time, when the product is received by the Company's customers. Reserves for Variable Consideration Revenues from product sales are recorded as product revenue at the net sales price (transaction price), which includes estimates of variable consideration that are reimbursable to customers for which reserves are established and which result from (a) shipping charges to end-users, (b) pharmacy dispensing and platform fees, (c) merchant and processing fees, (d) promotional discounts offered by the Company to end-users, and (e) reserves for expected product quality returns. These reserves for contractual adjustments are based on the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable (if the amount is payable to the customer) or a current liability (if the amount is payable to a party other than the customer). Where appropriate, these estimates take into consideration a range of possible outcomes that are probability-weighted for relevant factors such as the Company's historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company's best estimates of the amount of consideration to which the Company is entitled based on the terms of the contract(s). The amount of variable consideration that is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts of consideration ultimately received may differ from the Company's estimates. If actual results in the future vary from the Company's estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. The Company has no plan to seek government or commercial payor reimbursements in the US or the overseas markets. Therefore, reserves for variable consideration do not contain any components related to government and payor rebates or chargebacks. Product Returns The Company generally does not accept customer returns, except for product quality related cases. The Company evaluates quality related returns and adjusts the corresponding product warranty reserves and liabilities at least quarterly and at the end of each reporting period. Stock-Based Compensation Effective January 1, 2020, the Company accounts for all stock-based compensation awards granted to employees and non-employees in accordance with ASC 718, Compensation – Stock Compensation . The Company’s stock-based compensation consist primarily of stock options. The measurement date for share-based awards is the date of grant, and stock-based compensation costs are recognized as expense over the respective requisite service periods, which are typically the vesting period. The fair value of each stock option grant is estimated as of the date of grant using the Black-Scholes option-pricing model that requires management to apply judgment and make estimates, including: • exercise price: The exercise price is the fair market value on grant date, which shall mean the closing sale price of common stock, as reported on such market on that date (or if there are no market quotations for such date, the determination shall be made by reference to the last date preceding such date for which there are market quotations); • expected volatility: As the Company was previously a privately-owned company, there is not sufficient historical volatility for the expected term of the options. Therefore, the Company used an average historical share price volatility based on an analysis of reported data for a peer group of comparable companies for which historical information is available. For these analyses, the Company selects companies with comparable characteristics to itself including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The Company computes the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of its stock-based awards. The Company intends to consistently apply this process using representative companies until a sufficient amount of historical information regarding the volatility of its own share price becomes available; • risk-free interest rate, which is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption; • expected term, which is calculated using the simplified method, as prescribed by the Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment, as the Company has insufficient historical information regarding its stock options to provide a basis for an estimate. Under this approach, the weighted-average expected life is presumed to be the average of the contractual term of ten years and the weighted-average vesting term of the stock options, taking into consideration multiple vesting tranches; • dividend yield, which is zero based on the fact that the Company never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. Since the adoption of ASU 2018-07 on January 1, 2020, the measurement date for non-employee awards is the date of grant without changes in the fair value of the award. Stock-based compensation costs for non-employees are recognized as expense over the vesting period. Stock-based compensation expense is classified in the condensed consolidated statements of operations based on the function to which the related services are provided. Forfeitures are recorded as they occur.

Business Combination and Revers

Business Combination and Reverse Recapitalization	9 Months Ended
	Sep. 30, 2022
Business Combination and Reverse Recapitalization [Abstract]
Business Combination and Reverse Recapitalization	3. Business Combination and Reverse Recapitalization As discussed in Note 1, on January 13, 2022, the Company consummated the Business Combination pursuant to the Business Combination Agreement with CPSR dated July 19, 2021, as amended on November 8, 2021 and December 30, 2021 . Concurrently with the execution of the Business Combination Agreement, CPSR entered into subscription agreements with certain investors (the “PIPE Investors”). Pursuant to the subscription agreements, the PIPE Investors purchased an aggregate of 9,000,000 shares of CPSR’s Class A common stock (the “PIPE Investment”) in a private placement at a price of $ 10.00 per share for an aggregate purchase price of $ 90.0 million. The PIPE Investment was consummated in connection with the closing. On December 30, 2021, CPSR entered into a backstop agreement (the “Backstop Agreement”) with certain investors (the “Backstop Investors”). Pursuant to the Backstop Agreement, the Backstop Investors purchased an aggregate of 744,217 shares of CPSR’s Class A common stock (“Backstop Purchase Shares”) in a private placement at a price of $ 10.00 per share for an aggregate purchase price of $ 7.4 million. Additionally, CPSR issued the Backstop Investors 1,983,750 shares of CPSR Class A common stock as additional consideration. The Backstop Agreement was consummated in connection with the closing. The Business Combination was accounted for as a reverse recapitalization in accordance with U.S. GAAP. Under this method of accounting, CPSR, who was the legal acquirer, was treated as the acquired company for financial reporting purposes. Accordingly, the Business Combination was treated as the equivalent of Gelesis issuing stock for the net assets of CPSR, accompanied by a recapitalization. In connection with the Business Combination, aggregate transaction costs of $ 37.2 million were incurred, consisting of underwriting, legal, and other professional fees, of which $ 22.3 million were direct transaction costs incurred by CPSR, $ 9.5 million were assumed liabilities from CPSR, and $ 5.4 million were transaction costs incurred by Legacy Gelesis . Of the Legacy Gelesis transaction costs, $ 2.7 million was allocated to the Earnout Shares and expensed upon the Closing, based on the relative fair value of the Earnout Shares as compared to the other newly issued instruments as part of the Business Combination. The remaining transaction costs were recorded within additional paid-in capital on the accompanying condensed consolidated financial statements. The following table summarizes the net proceeds from the Business Combination, as reconciled to the accompanying condensed consolidated statements of noncontrolling interest, redeemable convertible preferred stock and stockholder’s equity (deficit) and the condensed consolidated statements of cash flows: Amount Cash - CPSR trust and cash (net of redemptions) $ 7,558 Cash - PIPE Investment 90,000 Cash - Backstop Agreement 7,442 Gross proceeds $ 105,000 Less: transaction costs, advisory fees and liabilities paid ( 34,522 ) Net proceeds from the Business Combination $ 70,478 Immediately prior to closing of the Business Combination, Legacy Gelesis common stock was split according to the exchange ratio of 2.59 , which was determined pursuant to the Business Combination Agreement and based on Legacy Gelesis’ implied price per share prior to the Business Combination. Upon closing of the Business Combination, holders received shares of common stock of the Company on a one-to-one basis. For periods prior to the Business Combination, in the accompanying condensed consolidated financial statements, the reported share and per share amounts have been retroactively converted (“Retroactive Application of Recapitalization”) by applying the exchange ratio. The consolidated assets, liabilities and results of operations prior to the Business Combination are those of Legacy Gelesis Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable convertible preferred stock converted into Legacy Gelesis common stock and was subsequently split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received shares of common stock of the Company on a one-to-one basis. Immediately prior to the closing of the Business Combination, Legacy Gelesis stock options and restricted stock units (“RSU”) were split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders of Legacy Gelesis stock options received a stock option to purchase shares of the Company’s common stock on a one-to-one basis and holder of Legacy Gelesis RSUs received RSUs of the Company on a one-to-one basis. Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable preferred stock warrants were converted into Legacy Gelesis common warrants and were subsequently split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received rollover common stock warrants of the Company on a one-to-one basis. Immediately prior to the closing of the Business Combination, Legacy Gelesis common warrants were split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received rollover common stock warrants of the Company on a one-to-one basis. The number of shares of common stock issued and outstanding immediately following the consummation of the Business Combination was as follows: Common Stock CPSR Public Stockholders 755,223 CPSR Sponsor Stockholders 4,916,250 Total CPSR Stockholders 5,671,473 Common stock issued to Gelesis Legacy Equityholders 54,814,847 Common stock issued to PIPE Investors and Backstop Agreement 11,727,967 Total common stock immediately after Closing 72,214,287 Earnout Shares In addition, each holder of Legacy Gelesis common stock, Legacy Gelesis options and Legacy Gelesis warrants will receive a pro rata portion of up to 23,482,845 restricted earnout shares of Gelesis Holding’s common stock, which will be issued and vest in equal thirds if the trading price of the Company’s common stock is greater than or equal to $ 12.50 , $ 15.00 and $ 17.50 , respectively, for any twenty ( 20 ) trading days within any thirty ( 30 )-trading day period on or prior to the date that is five years following the close of the Business Combination and will also vest in connection with any change of control transaction with respect to the Company if the applicable thresholds are met in such change of control transaction during the earnout period (each a “Triggering Event”). The Company determined 18,758,241 earnout shares are considered a contingent consideration arrangement in accordance with ASC 815, and recorded a liability upon the closing of the Business Combination of $ 58.9 million (see Note 14). The Company determined the remaining 4,724,604 earnout shares, which pertain to Legacy Gelesis equity awards, are incremental compensation in accordance with ASC 718 and equity classified. The total fair value of incremental compensation cost at the close of Business Combination was $ 14.8 million which will be expensed according to the vesting terms of the original underlying equity awards. The total incremental compensation cost, pertaining to Legacy Gelesis equity awards which had previously vested, was $ 11.4 million, of which $ 7.0 million and $ 4.4 million was recognized immediately following the close of the Business Combination as expense in selling, general and administrative expense and research and development expense, respectively, in the accompanying condensed consolidated statements of operations. Public Warrants and Private Placement Warrants Upon the closing of the Business Combination, the Company assumed 13,800,000 Public Warrants and 7,520,000 Private Placement Warrants. The Company determined the Public Warrants qualified as equity instruments in accordance with ASC 815 and reclassified the Public Warrants from liability to equity classification and the carrying value of $ 7.1 million was transferred to APIC on the accompanying condensed consolidated balance sheets. The Company determined the Private Placement Warrants met the definition of a liability under ASC 815 and recorded a liability reflecting the fair value of the Private Placement Warrants of $ 8.1 million. See Note 13 and Note 15 for further information on the Private Placement and Public Warrants, respectively.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at September 30, 2022 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Asset: Interest rate swap contract (see Note 12) $ 702 $ — $ 702 $ — Liabilities: Convertible promissory notes (see Note 12) 25,852 — — 25,852 Earnout liability (See Note 14) 3,376 — — 3,376 Private placement warrant liability (see Note 13) 590 — — 590 One S.r.l. call option 1,244 — — 1,244 Total liabilities measured at fair value $ 31,062 $ — $ — $ 31,062 Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at December 31, 2021 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Liabilities: Convertible promissory notes (see Note 12) $ 27,128 $ — $ — $ 27,128 Legacy Gelesis preferred stock warrants (See Note 13) 15,821 — — 15,821 One S.r.l. call option 2,416 — — 2,416 Total liabilities measured at fair value $ 45,365 $ — $ — $ 45,365 The following table presents a summary of the changes in the fair value of the Company’s Level 3 financial instruments during the nine months ended September 30, 2022: Convertible Promissory Notes Legacy Gelesis Redeemable Preferred Stock Warrants Liabilities One S.r.l. Call Option Earnout Liability Private Placement Warrant Liability Balance at December 31, 2021 $ 27,128 $ 15,821 $ 2,416 $ — $ — Assumed upon Business Combination — — — — 8,140 Recognized upon Business Combination — — — 58,871 — Issuance of convertible promissory notes 25,000 — — — — Changes in fair value 1,008 926 ( 808 ) ( 55,495 ) ( 7,550 ) Foreign currency translation adjustment — — ( 364 ) — — Conversion and exchange upon Business Combination — ( 16,747 ) — — — Settlement ( 27,284 ) — — — — Balance at September 30, 2022 $ 25,852 $ — $ 1,244 $ 3,376 $ 590 There were no transfers into or out of level 3 instruments and/or between level 1 and level 2 instruments during the nine months ended September 30, 2022 . The fair value of the interest rate swap contract is determined based on quoted price in markets that are not active for which significant inputs are observable either directly or indirectly and thus represents a level 2 measurement. The fair value measurement of the convertible promissory notes, Legacy Gelesis preferred stock warrant liability, One S.r.l. call option liability, earnout liability and private placement warrant liability utilized inputs not observable in the market and thus represents a Level 3 measurement.

Product Revenue and Reserve and

Product Revenue and Reserve and Allowances	9 Months Ended
	Sep. 30, 2022
Revenue From Contract With Customer [Abstract]
Product Revenue and Reserve and Allowances	5. Product Revenue and Reserve and Allowances The Company sells the Product principally to a limited number of customers consisting of telemedicine and online pharmacies, that in turn resell the Product to end-user patients and healthcare providers. Patients are required to have a prescription in order to purchase the Product in the United States. Revenue for the three and nine months ended September 30, 2022 and 2021 consisted of the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Roman Health Pharmacy LLC $ 4,793 $ 2,810 $ 18,208 $ 7,741 GoGoMeds 1,650 204 4,722 434 CMS — — — 118 Total $ 6,443 $ 3,014 $ 22,930 $ 8,293 Roman Health Pharmacy LLC ("Ro") On June 14, 2022, the Company entered into a Third Amended and Restated Supply and Distribution Agreement with Ro, pursuant to which the parties amended their previous agreement that granted Ro exclusive telehealth distributor rights to sell Plenity in the United States in the mail order/online pharmacy channel. Pursuant to the amendment, the Company received $ 15.0 million in cash from Ro as a pre-buy commitment to purchase units of Plenity, which was recorded to deferred income upon receipt in the accompanying condensed consolidated balance sheets. At September 30, 2022 and December 31, 2021, the Company recorded a deferred income balance o f $ 27.7 million and $ 31.0 million, respectively, in current liabilities in the accompanying condensed consolidated balance sheets with respect to Ro. GoGoMeds ("GGM") At September 30, 2022 and December 31, 2021 , the Company recorded an accounts receivable balance of $ 0.8 million and $ 0.8 million, respectively, prior to reserves and allowances (see below), in the accompanying condensed consolidated balance sheets with respect to GGM. CMS Bridging DMCC ("CMS") On August 4, 2022, the Company amended the License, Collaboration and Supply Agreement with CMS. Pursuant to the amendment, the one-time regulatory approval milestone payment of $ 5.0 million provided for in the original agreement became immediately payable. The discounted one-time regulatory approval milestone, which had a carrying value of $ 4.2 million and $ 4.1 million as of August 4, 2022 and December 31, 2021, respectively, included in other assets in the accompanying condensed consolidated balance sheets, was fully collected upon execution of the CMS amendment. In addition, the amendment expands the CMS Territory, and the Company also issued to CMS a warrant to purchase up to 400,000 shares of common stock, par value $ 0.0001 per share, at an exercise price of $ 0.01 per share. As a result of the amendment, during the three months ended September 30, 2022, the Company recognized licensing revenue of $ 0.2 million representing incremental consideration received by the Company for the additional territories granted to CMS in the accompanying condensed consolidated statement of operations, and $ 0.6 million of additional paid-in capital representing the fair value of the common stock warrants in the accompanying condensed consolidated balance sheets. The royalties and other commercial milestones will only be recognized in the periods in which the applicable subsequent sales occur. Reserves and Allowances The following table summarizes the activity in the product revenue reserve and allowance during the nine months ended September 30, 2022 and 2021 (in thousands): 2022 2021 Balance at December 31, $ 82 $ 14 Provision related to product sales 1,595 376 Credits and payments made ( 1,653 ) ( 365 ) Balance at September 30, $ 24 $ 25 At September 30, 2022 and 2021, product related reserve and allowances comprised solely contractual adjustments owed to the Company’s telehealth and online pharmacy partners, which were netted to accounts receivable in the Company’s condensed consolidated balance sheets for the year. Through September 30, 2022 , there had been no product related reserves or allowances owed to other parties, including the federal and state governments or their agencies.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2022
Inventory Disclosure [Abstract]
Inventories	6. Inventories Inventories consisted of the following (in thousands): September 30, December 31, 2022 2021 Raw materials $ 9,027 $ 8,074 Work in process 4,467 2,643 Finished goods 4,917 2,786 Total inventories $ 18,411 $ 13,503

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2022
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid Expenses And Other Current Assets	7. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2022 2021 Prepaid expenses $ 566 $ 982 Prepaid insurance 965 55 Prepaid manufacturing expenses 281 2,624 Prepaid contract research costs 173 262 Research and development tax credit 649 579 Value added tax receivable 2,411 5,633 Deferred financing costs — 3,855 Income tax receivable 186 213 Investment tax credit 645 — Prepaid expenses and other current assets $ 5,876 $ 14,203

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Property and Equipment, Net	8. Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): September 30, December 31, 2022 2021 Laboratory and manufacturing equipment $ 27,337 $ 28,101 Land and buildings 9,695 10,404 Leasehold improvements 1,399 1,614 Computer equipment and software 512 463 Capitalized software 232 228 Construction in process 22,495 22,097 Property and equipment – at cost 61,670 62,907 Less accumulated depreciation ( 6,518 ) ( 4,392 ) Property and equipment – net $ 55,152 $ 58,515 The Company owns and operates commercial manufacturing and research and development facilities in Italy, including a 51,000 square foot facility, which the Company expects to further expand to an 88,600 square foot facility, as well as approximately 12 acres of land, where the Company initiated construction of an additional 207,000 square foot facility. Both facilities are near the Town of Lecce in the Puglia region of Italy. Property and equipment classified as construction in process at September 30, 2022 and December 31, 2021 are related to the development of manufacturing lines that have not yet been placed into service at September 30, 2022 and December 31, 2021, respectively. Depreciation expense was approximately $ 0.3 million and $ 0.2 million for the three months ended September 30, 2022 and 2021, respectively, and $ 2.1 million and $ 0.6 million for the nine months ended September 30, 2022 and 2021 , respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2022
Payables And Accruals [Abstract]
Accrued Expenses	9. Accrued Expenses Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Accrued payroll and related benefits $ 2,921 $ 1,384 Accrued professional fees and outside contractors (including 128 and $ 60 , respectively) 4,482 4,359 Accrued property, plant and equipment additions 481 1,257 Accrued inventory and manufacturing expense 362 128 Unpaid portion of acquisition of intangible asset and 2,412 5,604 Tax payables 26 145 Deferred legal fees 738 738 Accrued interest 834 45 Total accrued expenses $ 12,256 $ 13,660

Other Long-Term Liabilities

Other Long-Term Liabilities	9 Months Ended
	Sep. 30, 2022
Other Liabilities Disclosure [Abstract]
Other Long-Term Liabilities	10. Other Long-Term Liabilities Other long-term liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Long-term tax liabilities $ 85 $ 182 Contingent loss for research and development tax credits 2,583 2,990 One S.r.l. call option (see Note 11) 1,244 2,416 Total other long-term liabilities $ 3,912 $ 5,588

Significant Agreements

Significant Agreements	9 Months Ended
	Sep. 30, 2022
Significant Agreements [Abstract]
Significant Agreements	11. Significant Agreements Puglia 1 Grant In May 2020, the Company was awarded a grant by the Puglia region of Italy as an incentive to manufacture and carry out research and development activities in Italy (“PIA 1 Grant”). The Company recognized grant income of $ 0.6 million and $ 0.5 million in other income, net, on the accompanying condensed consolidated statements of operations during the nine months ended September 30, 2022 and 2021 , respectively, related to the PIA 1 Grant, of which less than $ 0.1 million and $ 0.5 million was attributable to research and development expenses and investments in facilities and equipment, respectively, during the nine months ended September 30, 2022 and $ 0.2 million was attributable to both research and development expenses and investments in facilities and equipment, respectively, during the nine months ended September 30, 2021 . The Company recorded $ 5.0 million and $ 6.4 million of deferred income in the accompanying condensed consolidated balance sheets at September 30, 2022 and December 31, 2021 , respectively, of which $ 0.7 million and $ 0.9 million was recorded as a current liability, respectively, as it is expected to be recognized within one year of the date of the accompanying condensed consolidated balance sheets. The Company collected zero proceeds from the PIA 1 Grant during the nine months ended September 30, 2022 , and recorded a grant receivable of $ 4.7 million and $ 5.4 million in the accompanying condensed consolidated balance sheets at September 30, 2022 and December 31, 2021, respectively. Puglia 2 Grant In November 2020, the Company was awarded a second grant by the Puglia region of Italy as an incentive to manufacture and carry out research and development activities in Italy (“PIA 2 Grant”). The Company recognized grant income o f $ 1.3 million and $ 1.0 million in other income, net, on the accompanying condensed consolidated statements of operations during the nine months ended September 30, 2022, and 2021 , respectively, related to the PIA 2 Grant, which was attributable to research, development expenses and qualified investments in manufacturing facilities. The Company has recorded $ 3.2 million and $ 3.7 million of deferred income in the accompanying condensed consolidated balance sheets at September 30, 2022 and December 31, 2021 , respectively, of which $ 0.3 million and $ 0.4 million was recorded as a current liability, respectively, as it is expected to be recognized within one year of the date of the accompanying condensed consolidated balance sheets. The Company collected zero proceeds from the PIA 2 Grant during the nine months ended September 30, 2022 , and has recorded a grant receivable of $ 4.3 million and $ 3.6 in the accompanying condensed consoli dated balance sheets at September 30, 2022 and December 31, 2021, respectively. At September 30, 2022 , $ 4.3 million of the PIA2 grant receivable was expected to be collected in more than twelve months and was included in other assets in the accompanying condensed consolidated balance sheets. One S.r.l. (“One”) Amended Patent License and Assignment Agreement In June 2019, the Company amended and restated an existing master agreement with One (the “2019 One Amendment”), the original inventor of the Company’s core patents and a related party to the Company (see Notes 19 and 20). Under the amended and restated master agreement following this transaction, the Company eliminated certain future commercial milestone obligations and received a reduction in the percentage of royalties the Company was required to pay on future net sales. In return, One received additional consideration consisting of new future milestones upon the commercial success of new medical indications and a contingently issuable warrant for redeemable convertible preferred stock. Additionally, the Company acquired a 10 % equity interest in One in exchange for cash consideration. The Company accounted for the reduction in royalties the Company is required to pay on future net revenues that resulted from the 2019 One Amendment as an intangible asset under ASC 350, Intangibles – Goodwill and Other, which shall be amortized over its useful life, which was determined to be the earliest expiration of patents related to the underlying intellectual property in November 2028. The Company accounted for the acquisition of the 10 % equity interest in One under ASC 323, Investments – Equity Method and Joint Ventures. In connection with the acquisition of the 10 % equity interest in One, the Company made a payment of $ 2.9 million to One shareholders during the nine months ended September 30, 2022 . The Company had remaining undiscounted payments of € 2.5 million and € 5.0 million due to One at September 30, 2022 and December 31, 2021 , respectively (approximately $ 2.4 million and $ 5.7 million due to One at September 30, 2022 and December 31, 2021, respectively). The remaining payments at September 30, 2022 were recorded in accrued expenses in the accompanying condensed consolidated balance sheets as it is expected to be settled within the next twelve months. None of the future milestones under the amended and restated master agreement, have been met, or are deemed to be probable of being met, at the transaction date or at September 30, 2022 and December 31, 2021, respectively. A summary of the intangible asset activity that resulted from this transaction during the nine months ended September 30, 2022 is as follows (in thousands): Intangible Assets Intangible asset at relative fair value $ 15,564 Adjustment to record deferred tax liability 5,783 Carrying value of intangible asset at June 2019 acquisition date 21,347 Cumulative amortization expense ( 5,667 ) Balance at December 31, 2021 $ 15,680 Period amortization expense ( 1,700 ) Balance at September 30, 2022 $ 13,980 In October 2020, the Company further amended the terms of the agreement with One to cancels its obligation to issue a warrant for redeemable convertible preferred stock in the 2019 One Amendment for additional commercial milestone consideration and a warrant to purchase common stock. Additionally, the Company granted One a contingent call option to buy back the 10 % ownership that the Company acquired in the 2019 One Amendment at an exercise price of € 6.0 million (approximately $ 5.9 million at September 30, 2022). The call option is only exercisable upon (1) a change of control or a deemed liquidation event by the Company, as defined, in the Company’s Restated Certification of Incorporation (2) the date in which the Company’s current Chief Executive Officer is no longer affiliated with the Company in his capacity as either an executive officer or a member of the board of directors. On August 9, 2022, the Company amended the exercise price of the One warrantholders' 1,353,062 previously issued common stock warrants from $ 4.26 to $ 1.45 , in consideration for deferring payment of the remaining purchase price totaling € 2.5 million (approximately $ 2.4 million at September 30, 2022 ) to acquire the 10 % equity interest in One until March 31, 2023. The Company recognized a loss attributable to the amendment to the Warrant Purchase Agreement of $ 0.3 million during the three months ended September 30, 2022. The One S.r.l. call option was recorded as a liability held at fair value at the date of issuance and is remeasured at each subsequent reporting date with changes in fair value recorded in other income (expense) in the accompanying condensed consolidated statements of operations. Fair value is determined using a Black-Scholes option pricing model. The significant inputs used in estimating the fair value of call option liability include the estimated fair value of the underlying stock price, expected term, risk free interest rate, and expected volatility. The following represents a summary of the changes to Company’s One S.r.l. call option liability during the nine months ended September 30, 2022 (in thousands): Balance at December 31, 2021 $ 2,416 Change in fair value ( 808 ) Foreign currency translation gain ( 364 ) Balance at September 30, 2022 $ 1,244 The following weighted average assumptions were used to determine the fair value of the One S.r.l. call option liability at September 30, 2022 and December 31, 2021: September 30, December 31, 2022 2021 Expected term 4.0 years 2.0 years Expected volatility 75.0 % 62.0 % Expected dividend yield 0.0 % 0.0 % Risk free interest rate 4.3 % 0.70 % Estimated fair value of ownership interest $ 2,928 $ 6,922 Exercise price of call option $ 5,879 $ 6,806 Research Innovation Fund (“RIF”) Financing In August 2020, the Gelesis S.r.l. entered into a loan and equity agreement with RIF, an investment fund out of the EU, whereby Gelesis S.r.l. received € 10.0 million (approximately $ 9.8 million at September 30, 2022 ) from RIF as an equity investment and € 15.0 million (approximately $ 14.7 million at September 30, 2022 ) as a loan with a fixed interest rate of 6.35 % per annum (see Note 12). The equity investment can be called by the Company, beginning in December 2023 and ending in December 2026, by paying the investment plus 15 % percent annual interest. If the Company does not exercise this call option, beginning in January 2027 and ending in December 2027, RIF may put the investment to the Company at a cost of the investment amount plus 3.175 % percent annual interest. The loan has a termination date of December 31, 2030 and is repayable over 8 years starting 24 months subsequent to its issuance. Any unpaid principal and interest must be repaid upon exercise of the call option by the Company, or subsequent exercise of a put option by RIF. At September 30, 2022 , RIF holds approximately 20 % of the equity of Gelesis S.r.l. The Company recorded accretion of $ 0.3 million and foreign currency translation gain of $ 1.6 million to the noncontrolling interest during the nine months ended September 30, 2022 . The noncontrolling interest balance was $ 10.5 million and $ 11.9 million at September 30, 2022 and December 31, 2021 , respectively, in the accompanying condensed consolidated balance sheets.

Debt

Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Debt	12. Debt The Company’s non-convertible debt outstanding at September 30, 2022 and December 31, 2021 is summarized as follows: September 30, December 31, 2022 2021 Italian Economic Development Agency Loan 303 525 Intesa Sanpaolo Loan 1 6,709 8,507 Intesa Sanpaolo Loan 2 4,899 5,672 Horizon 2020 Loan 388 486 RIF Shareholders Loan 14,698 17,015 UniCredit Loan 4,863 5,630 Total debt obligation $ 31,860 $ 37,835 Unamortized loan discount and issuance costs ( 895 ) ( 754 ) Total debt obligation carrying amount $ 30,965 $ 37,081 Current portion $ 4,249 $ 1,950 Long-term portion $ 26,716 $ 35,131 2021 Bridge Financing On December 13, 2021, the Company issued convertible promissory notes to related parties in the principal amount of $ 27.0 million (see Note 20). At December 31, 2021, the outstanding balance was $ 27.1 million, recorded at fair value in the accompanying condensed consolidated balance sheets. On January 19, 2022 the Company settled the convertible promissory notes in cash for principal plus accrued interest in the aggregate amount of $ 27.3 million. During the nine months ended September 30, 2022 , the Company recognized a loss of $ 0.2 million with respect to the change in fair value of the convertible promissory notes on the accompanying condensed consolidated statements of operations. 2022 Promissory Notes On July 25, 2022 and August 4, 2022, the Company issued three term promissory notes in the aggregate principal amount of $ 25.0 million to existing investor CMS, and existing investors and related parties PureTech Health LLC and SSD2 LLC, for an aggregate cash purchase price of $ 25.0 million. Each of the promissory notes is unsecured and bears interest at a rate of 15 % per annum. Each promissory note matures on the earlier of (a) December 31, 2023 or (b) five ( 5 ) business days following a qualified financing. Upon a payment default under any promissory note that has not been cured after five days (i) the Company will be required to issue certain warrants to the holders as defined by the promissory note agreements and (ii) the holders will have the option to convert outstanding principal and accrued interest into a number of shares of Gelesis common stock as defined by the promissory note agreements. At September 30, 2022 , the aggregate outstanding balance of the promissory notes was $ 25.9 million recorded at fair value in the accompanying condensed consolidated balance sheets. During the three months ended September 30, 2022 , the Company recognized a loss of $ 0.8 million with respect to the change in the fair value of the 2022 promissory notes. The Company applied the provisions of ASC 815-15, Embedded Derivatives, elected to account for the convertible promissory notes at fair value, and to not bifurcate the embedded derivative . The fair value of the promissory notes is determined using a multiple scenario-based valuation method. The fair value of the hybrid instrument was determined by calculating the value of the instrument in each scenario “with” the respective conversion feature and “without”. The significant inputs used in estimating the fair value of the convertible promissory notes include the estimated discount rate, expected term, and the outcome probability with respect to each scenario. The following assumptions were used to determine the fair value of the 2022 convertible promissory notes at September 30, 2022: At September 30, 2022 Expected term 1.25 years Weighted average discount rate 26.0 % Probability of repayment after qualified financing 50.0 % Probability of holder electing conversion option 50.0 % Interest Rate Swap Contract on Intesa Sanpaolo Loan 1 In November 2019, the Company entered into an interest rate swap ("IRS") contract with Intesa Sanpaolo S.p.A. concurrently with the execution of the Intesa Sanpaolo loan 1 agreement. The IRS contract covered the same period as the underlying Intesa Sanpaolo loan 1 and expires on October 31, 2029 . Fair value of the interest rate swap contract is determined based on quoted price in markets that are not active for which significant inputs are observable either directly or indirectly and thus represents a level 2 measurement. The Company reported a fair value of $ 0.7 million for the IRS contract included other assets at September 30, 2022 , and $ 0.1 million included in other long-term liabilities at December 31, 2021 in the accompanying condensed consolidated balance sheets. Net gain attributable to the change in fair value of the IRS contract was $ 0.8 million for the nine months ended September 30, 2022 . Net loss attributable to the change in fair value of the IRS contract was $ 0.1 million for the nine months ended September 30, 2021. Future maturities with respect to debt outstanding at September 30, 2022 are as follows (in thousands): At September 30, 2022 Remaining 2022 obligation $ 1,063 2023 33,268 2024 4,985 2025 3,627 2026 3,646 More than 5 years 11,123 Total maturities $ 57,712

Warrant Liabilities

Warrant Liabilities	9 Months Ended
	Sep. 30, 2022
Warrants And Rights Note Disclosure [Abstract]
Warrants	13. Warrant Liabilities The following represents a summary of the warrant liabilities activity during the nine months ended September 30, 2022: Series A-4 Private Placement Warrants Total Balance at December 31, 2021 $ 15,821 $ — $ 15,821 Assumed upon Business Combination — 8,140 8,140 Changes in fair value 926 ( 7,550 ) ( 6,624 ) Conversion and exchange upon Business Combination ( 16,747 ) — ( 16,747 ) Balance at September 30, 2022 $ — $ 590 $ 590 Private Placement Warrants At September 30, 2022 , there were 7,520,000 Private Placement Warrants outstanding exercisable at $ 11.50 per share for common stock at the same terms as the Public Warrants. However, the warrants will not be redeemable by the Company for cash so long as they are held by the initial stockholders or their permitted transferees. The initial purchasers of the Private Placement Warrants, or their permitted transferees, also have the option to exercise the Private Placement Warrants on a cashless basis. If Private Placement Warrants are held by holders other than the initial purchasers thereof or their permitted transferees, the Private Placement Warrants will be redeemable by the Company and exercisable by the holders on the same basis as the Public Warrants. The warrants were initially recorded at fair value with subsequent changes in fair value being recorded in the accompanying condensed consolidated statements of operations. The warrants at issuance and at September 30, 2022, were valued utilizing a modified Monte Carlo Simulation value model and significant unobservable Level 3 inputs. The following weighted-average assumptions were used to determine the fair value of the Private Placement Warrant liability at September 30, 2022: Private Placement Warrants Expected term 4.3 years Expected volatility 66.0 % Expected dividend yield 0.0 % Risk free interest rate 4.0 % Price of Gelesis Common Stock $ 1.08 Exercise price of warrants $ 11.50 Legacy Gelesis Redeemable Preferred Stock Warrants In connection with the Business Combination, Legacy Gelesis redeemable preferred stock warrants were reclassified from liability treatment to equity treatment pursuant to the terms of their exchange (see Note 15).

Earnout Liability

Earnout Liability	9 Months Ended
	Sep. 30, 2022
Derivative Instrument Detail [Abstract]
Earnout Liability	14. Earnout Liability The following represents a summary of the earnout liability activity during the nine months ended September 30, 2022: Earnout Liability Balance at December 31, 2021 $ — Recognized upon Business Combination 58,871 Changes in fair value ( 55,495 ) Balance at September 30, 2022 $ 3,376 At Business Combination close and at September 30, 2022 , there were 18,758,241 earnout shares underlying the liability, which were unissued and unvested. At September 30, 2022, none of the triggering events had been met. The earnout liability was initially recorded at fair value with subsequent changes in fair value being recorded in the accompanying condensed consolidated statements of operations. The earnout liability at issuance and at September 30, 2022, were valued utilizing a Monte Carlo Simulation and significant unobservable Level 3 inputs. The following weighted-average assumptions were used to determine the fair value of the earnout liability at September 30, 2022: Earnout Liability Expected term 4.3 years Expected volatility 66.0 % Expected dividend yield 0.0 % Risk free interest rate 4.0 % Price of Gelesis Common Stock $ 1.08

Stockholder's Equity (Deficit)

Stockholder's Equity (Deficit)	9 Months Ended
	Sep. 30, 2022
Stockholders Equity Note [Abstract]
Stockholder's Equity (Deficit)	15. Stockholder's Equity (Deficit) Common Stock The Company’s authorized capital stock consists of (a) 900,000,000 shares of common stock, par value $ 0.0001 per share; and (b) 250,000,000 shares of preferred stock, par value $ 0.0001 per share. At September 30, 2022, there were 72,983,488 shares of common stock issued and outstanding. Common Stock Purchase Agreement On August 11, 2022, the Company entered into a Common Stock Purchase Agreement and a Registration Rights Agreement (the "Purchase Agreement") with B. Riley Principal Capital II, LLC (“B. Riley”). Pursuant to the agreement, the Company will have the right, but not the obligation, to sell to B. Riley up to the lesser of (i) $ 50,000,000 of newly issued shares of common stock, and (ii) 14,506,475 shares of common stock (which is the number of shares equal to approximately 19.99 % of the aggregate number of shares of the Company's common stock issued and outstanding immediately prior to the execution of the agreement) at 97 % of the volume weighted average price (“VWAP”) of the Company's common stock calculated in accordance with the Purchase Agreement, from time to time during the 24-month term commencing from the effectiveness date of the corresponding Form S-1 registration statement on September 6 th , 2022. Sales and timing of any sales of Class A common stock are solely at the election of the Company, and the Company is under no obligation to sell any securities to B. Riley under the Purchase Agreement. As consideration for B. Riley’s commitment to purchase shares of the Company’s common stock, the Company issued 355,361 shares of its common stock as commitment shares. The Company incurred an aggregate cost of approximately $ 1.2 million in connection with the Purchase Agreement, including $ 0.5 million for the fair value of the 355,361 commitment shares issued to B. Riley. The Company recorded $ 1.2 million legal and professional costs in the accompanying condensed consolidated statement of operations during the three months ended September 30, 2022 , and recorded $ 0.5 million of additional paid-in capital in the accompanying condensed consolidated balance sheets as of September 30, 2022 with respect to the fair value of the 355,361 common stock commitment shares issued to B. Riley. The Company issued a total of 34,246 shares of its common stock and raised less than $ 0.1 million gross proceeds under the Purchase Agreement for the three months ended September 30, 2022. Legacy Redeemable Convertible Preferred Stock At December 31, 2021 and immediately prior to the Business Combination, Legacy Gelesis had outstanding Series A-1, Series A-2, Series A-3, Series A-4, Series A-5, Series Growth, Series 2 Growth and Series 3 Growth redeemable convertible preferred stock which are collectively referred to as “redeemable convertible preferred stock.” Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable convertible preferred stock converted into Legacy Gelesis common stock and was subsequently split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received shares of common stock of the Company on a one-to-one basis. Public Warrants In connection with the Business Combination the Company assumed 13,800,000 Public Warrants, which entitle the holder to acquire common stock, which are exercisable at an exercise price of $ 11.50 per share. The Public Warrants will expire at on the earlier to occur of five years after the completion of the Business Combination or redemption. Once the Public Warrants become exercisable, the Company may call the Public Warrants for redemption for cash: • in whole and not in part; • at a price of $ 0.01 per warrant; • upon not less than thirty (30) days’ prior written notice of redemption (the “ 30-day redemption period”) to each warrant holder; and • if, and only if, the closing price of the Common Stock equals or exceeds $ 18.00 per share (as adjusted for stock splits, stock capitalizations, reorganizations, recapitalizations and the like) for any twenty( 20 ) trading days within a thirty ( 30 )-trading day period ending three (3) business days before the Company sends the notice of redemption to the warrant holders. If the Company calls the Public Warrants for redemption, the Company will have the option to require all holders that wish to exercise the Public Warrants to do so on a cashless basis, as described in the warrant agreement. Additionally, in no event will the Company be required to net cash settle. At September 30, 2022 , there were 13,800,000 Public Warrants outstanding. Rollover Warrants Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable preferred stock warrants were converted into Legacy Gelesis common warrants and were subsequently split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received rollover common stock warrants of the Company on a one-to-one basis. At close of Business Combination and September 30, 2022 , there were 1,836,429 and 1,660,303 rollover warrants outstanding, respectively, with an exercise price of $ 0.02 . During the nine months ended September 30, 2022 , 176,126 rollover warrants were exercised for proceeds of less than $ 0.1 million. Immediately prior to the closing of the Business Combination, existing Legacy Gelesis common warrants were also split according to the exchange ratio of 2.59 . Upon closing of the Business Combination, holders received shares of common stock of the Company on a one-to-one basis. At close of Business Combination and at September 30, 2022 , respectively, there were 1,353,062 of these warrants outstanding with an exercise price of $ 4.26 . At September 30, 2022 and December 31, 2021 common stock reserved for future issuances was as follows: September 30, December 31, 2022 2021 Common stock issued upon option exercise and RSUs vesting 18,694,129 13,486,708 Conversion of all classes of redeemable convertible — 48,566,655 Issuances upon exercise of warrants to purchase Series A-4, — 1,836,429 Issuances upon exercise of common stock warrants 24,733,365 1,353,062 Earnout shares 23,482,845 — Total common stock reserved for future issuance 66,910,339 65,242,854

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	16. Stock-Based Compensation 2021 Stock Option Plan In January 2022, the Company's Board of Directors approved the 2021 Stock Option and Incentive Plan (the "2021 Plan"), which supersedes the 2016 Stock Option and Grant Plan and the 2006 Stock Incentive Plan and provides for the grant of incentive stock options, nonqualified stock options, restricted stock awards and restricted stock units to employees, directors, and nonemployees of the Company. The 2021 Plan was authorized initially to issue 9,583,570 shares, plus on January 1, 2023 and each January 1 thereafter, the number of shares of Stock reserved and available for issuance under the Plan shall be cumulatively increased by 4 percent of the number of shares of Stock issued and outstanding on the immediately preceding December 31. Under the 2021 Plan, 3,321,470 shares remained available for issuance at September 30, 2022. Options and restricted stock awards generally vest based on the grantee’s continued service with the Company during a specified period following a grant as determined by the Board of Directors and expire ten years from the grant date. In general, awards typically vest in three to four years , but vesting conditions can vary based on the discretion of the Company’s Board of Directors. The fair value of the options is estimated at the grant date using Black-Scholes and recognized over the vesting period, taking into account the terms and conditions upon which options are granted. The fair value of restricted stock awards is the fair value at the date of grant reduced by the exercise price of the award, if any. The fair value of both options and restricted stock awards are amortized on a straight-line basis over the requisite service period of the awards. Stock-based compensation expense is summarized for employees and nonemployees, by category in the accompanying condensed consolidated statements of operations as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 1,058 $ 243 $ 9,131 $ 1,304 Selling, general and administrative 3,516 843 17,408 2,876 Total $ 4,574 $ 1,086 $ 26,539 $ 4,180 Stock Option Activity The following table summarizes the Company’s stock option activity during the nine months ended September 30, 2022: Number of Weighted- Weighted- Aggregate Outstanding at December 31, 2021 4,889,820 $ 10.39 6.17 $ 54,449 Retroactive application of reverse recapitalization 7,784,666 ( 6.38 ) Adjusted and Outstanding at December 31, 2021 12,674,486 $ 4.01 6.17 $ 54,449 Granted 2,658,185 $ 3.35 Exercised ( 162,064 ) $ 0.68 Forfeited - unvested ( 548,653 ) $ 5.23 Forfeited - vested ( 63,718 ) $ 4.31 Expired ( 456,534 ) $ 1.23 Outstanding at September 30, 2022 14,101,702 $ 3.96 6.31 $ 502 Exercisable at September 30, 2022 10,218,998 $ 3.89 5.30 $ 502 Vested and Expected to Vest at September 30, 2022 14,101,702 $ 3.96 6.31 $ 502 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the common stock. The total fair value of options vested during the nine months ended September 30, 2022 was $ 3.9 million. The fair value of each option issued was estimated at the date of grant using Black-Scholes with the following weighted-average assumptions: For the Nine Months Ended September 30, 2022 Market price of common stock $ 3.35 Expected volatility 72.4 % Expected term (in years) 6.1 Risk-free interest rate 1.7 % Expected dividend yield 0.0 % The weighted-average grant date fair value of stock options granted during the nine months ended September 30, 2022 was $ 2.17 . At September 30, 2022 and December 31, 2021 , there was $ 10.1 million and $ 8.7 million, respectively, of unrecognized compensation cost related to unvested stock option grants under the 2021 Plan, which was expected to be recognized over a weighted-average period of 2.3 and 2.2 years, respectively. Restricted Stock Unit (“RSU”) Activity The following table summarizes the Company’s RSU activity during the nine months ended September 30, 2022: Number of RSUs Weighted- Outstanding and Unvested at December 31, 2021 313,354 $ 21.41 Retroactive application of reverse recapitalization 498,868 $ ( 13.15 ) Adjusted and Outstanding and Unvested at December 31, 2021 812,222 $ 8.26 Granted 4,555,197 $ 3.46 Vested ( 41,404 ) $ 6.77 Forfeited ( 640,849 ) $ 3.35 Outstanding and Unvested at September 30, 2022 4,685,166 $ 4.28 Each RSU entitles the holder to one share of common stock on vesting and the RSU awards are based on a cliff vesting schedule over requisite service periods in which the Company recognizes compensation expense for the RSUs. Vesting of the RSUs is subject to the satisfaction of certain service and or certain performance conditions. The Company recognizes the estimated grant date fair value of these awards as stock-based compensation expense over the service and or performance periods based upon its determination of whether it is probable that the service and or performance conditions will be achieved. The Company assesses the probability of achieving the service and or performance conditions at each reporting period. Cumulative adjustments, if any, are recorded to reflect subsequent changes in the estimated or actual outcome of service and or performance-related conditions. At September 30, 2022 and December 31, 2021 , unrecognized compensation cost for RSU awards granted totaled $ 10.7 million and $ 6.7 million, respectively, which was expected to be recognized over a weighted-average period of 2.9 and 0.9 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	17. Income Taxes The Company did no t record any income tax provision during the three months ended September 30, 2022 and 2021, respectively. The Company recorded zero and less than $ 0.1 million income tax provision during the nine months ended September 30, 2022 and September 30, 2021 , respectively. The provision recorded differs from the US statutory rate of 21 % for the nine months ended September 30, 2022 and September 30, 2021 primarily due to the valuation allowance recorded against the net operating losses and deferred tax assets. The Company continues to evaluate the positive and negative evidence bearing upon the realizability of its net deferred tax assets and determined that it is not more likely than not that the Company will recognize the benefits of the net deferred tax assets. Therefore, a full valuation allowance has been recorded against the balance of net deferred tax assets as of September 30, 2022 and December 31, 2021, respectively.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	18. Earnings (Loss) per Share The weighted-average common shares outstanding and thus the net loss per share calculations and potentially dilutive security amounts for all periods prior to the Business Combination have been retrospectively adjusted to the equivalent number of shares outstanding immediately after the Business Combination to effect the reverse recapitalization. Historically reported weighted average shares outstanding have been multiplied by the exchange ratio of approximately 2.59 . See Note 3 for further information. Basic and diluted loss per share attributable to common stockholders was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 14,149 ) $ ( 30,730 ) $ ( 32,365 ) $ ( 74,055 ) Accretion of redeemable convertible preferred stock to redemption value — ( 23,111 ) ( 37,934 ) ( 139,237 ) Accretion of noncontrolling interest put option to redemption value ( 80 ) ( 95 ) ( 253 ) ( 285 ) Net loss attributable to common stockholders $ ( 14,229 ) $ ( 53,936 ) $ ( 70,552 ) $ ( 213,577 ) Denominator: Weighted average common shares outstanding, basic and diluted 72,772,627 5,615,192 69,349,679 5,592,931 Net loss per share, basic and diluted $ ( 0.20 ) $ ( 9.61 ) $ ( 1.02 ) $ ( 38.19 ) The Company’s potential dilutive securities, which include stock options, RSUs, warrants and earnout shares have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted-average number of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same for all periods presented. The Company excluded the following potential common stock, presented based on amounts outstanding at September 30, 2022 and 2021 from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect. September 30, 2022 2021 Convertible preferred stock — 48,566,655 Warrants on convertible preferred stock — 1,836,429 Options and RSUs to acquire common stock 18,694,129 13,555,474 Warrants on common stock 24,733,365 1,353,062 Earnout shares — — Total 43,427,494 65,311,620 Total potentially dilutive common share equivalents for the three and nine months ended September 30, 2022 , excludes 23,482,845 shares related to the earnout liability as these shares are contingently issuable upon meeting certain triggering events.

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	19. Commitments and Contingencies Operating Leases In June 2019 , the Company entered into an operating lease agreement with PureTech Health LLC, or PureTech, for office space located in Boston, Massachusetts. The lease expires in August 2025 , with total lease payments of $ 3.2 million over the term. At September 30, 2022 , the Company’s operating lease right of use assets was $ 1.6 million, of which $ 0.6 million and $ 1.1 million were the corresponding short-term and long-term lease liabilities, respectively. At December 31, 2021, the Company’s operating lease right of use assets was $ 2.0 million, of which $ 0.5 million and $ 1.5 million were short-term and long-term lease liabilities, respectively. Operating lease expense was $ 0.2 million during the three months ended September 30, 2022 and 2021, respectively. Operating lease expense was $ 0.5 million during the nine months ended September 30, 2022 and 2021, respectively. The remaining noncancelable term of the Company’s operating leases was 2.9 years at September 30, 2022 , and the weighted average discount rate was 5.3 %. Future maturities of the lease liability under the Company’s noncancelable operating leases at September 30, 2022 are as follows (in thousands): At September 30, 2022 Remaining 2022 maturities $ 163 2023 649 2024 567 2025 381 2026 29 More than 5 years 13 Total undiscounted lease maturities $ 1,802 Imputed interest ( 129 ) Total lease liability $ 1,673 Royalty Agreements Expenses from royalty agreements on net product sales and sublicense income is recognized as a cost of goods sold in the accompanying condensed consolidated statements of operations during the period in which the associated revenues are recognized. PureTech In December 2009, the Company entered into a royalty and sublicense income agreement with PureTech, a significant stockholder in the Company, whereby the Company is required to pay PureTech a 2.0 % royalty on net product sales received as a result of developing products and technology using the intellectual property purchased from One. One S.r.l Under the amended and restated master agreement with One, the Company is required to pay a 2.0 % royalty on net product sales and an aggregate of € 17.5 million (approximately $ 17.1 million at September 30, 2022) upon the achievement of certain commercial milestones of new medical indications as well as Plenity and pay royalties on net product sales and/or a percentage of sublicense income. At September 30, 2022, none of the milestones have been met. Grant Agreements The Company has been awarded grants from governmental agencies, which are recognized as income as the qualifying expenses are incurred (see Note 11). The grant agreements contain certain provisions, including, among others, maintaining a physical presence in the region for defined periods. Failure to comply with these covenants would require either a full or partial refund of the grant to the granting authority. Research and Development Tax Credits The Company’s subsidiary, Gelesis S.r.l., which conducts core manufacturing and research and development activities on behalf of the Company, is eligible to receive a non-income based and non-refundable tax credits for qualified research and development activities. The Company has earned research and development tax credits in Italy for qualifying expenses incurred by performing certain research and development activities. In December 2018, the Italian government passed a new budget law, effective January 1, 2019, that amended the eligibility criteria for recognizing qualifying research and development tax credits (“2019 Budget Law”). The 2019 Budget Law requires retroactive application for research and development tax credits earned during the year ended December 31, 2019. Under the 2019 Budget Law, research and development tax credits claimed in prior periods under previous interpretations of the research and development tax credit law may potentially be repaid by the Company. The Company evaluated the potential loss under ASC 450, Contingencies . The Company concluded that the likelihood of a potential loss arising from this matter is probable. The Company has recorded $ 2.6 million and $ 3.0 million as a component of other long-term liabilities in the accompanying condensed consolidated balance sheets at September 30, 2022 and December 31, 2021, respectively. In October 2021, the Italian federal tax authority initiated an audit of the research and development tax credits for the calendar years 2017 through 2019. The Company has had interactions during 2022 with the Italian federal tax authority regarding the tax audit. Litigation In connection with the Business Combination, the Company received a litigation demand letter from certain purported stockholders alleging that the Company was required to provide holders of Class A Common Stock a separate class vote in connection with proposed amendments of the Company's Amended and Restated Certificate of Incorporation to increase the number of authorized shares, such that separate votes can be cast on the proposed increase in the number of shares of Class A common stock and the proposed increase in the number of shares of preferred stock. During the nine months ended September 30, 2022 , the Company reached an agreement to resolve the claim and settled for an immaterial cash payment.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	20. Related Party Transactions The Company had the following transactions with related parties: PureTech In June 2019, PureTech executed a sublease agreement with the Company (see Note 19). With respect to the sublease, the Company incurred lease expense of $ 0.1 million and $ 0.1 million during the three months ended September 30, 2022 and 2021, respectively, and $ 0.4 million and $ 0.2 million during the nine months ended September 30, 2022 and 2021, respectively, recorded in general and administrative expenses in the accompanying condensed consolidated statements of operations. The Company incurred royalty expense of $ 0.1 million and less than $ 0.1 million during the three months ended September 30, 2022 and 2021, respectively, and $ 0.5 million and $ 0.3 million in connection with the PureTech royalty agreement (see Note 19) during the nine months ended September 30, 2022 and 2021 , respectively, recorded in cost of goods sold in the accompanying condensed consolidated statements of operations. The Company had an accounts payable balance to PureTech of $ 0.3 million and $ 0.1 million at September 30, 2022 and December 31, 2021, respectively, in the accompanying condensed consolidated balance sheets. On December 13, 2021, the Company issued a convertible promissory note to PureTech in the principal amount of $ 15.0 million (see Note 12). At December 31, 2021, the outstanding balance was $ 15.1 million, recorded at fair value in the accompanying condensed consolidated balance sheets. On January 19, 2022 the Company settled the convertible promissory notes in cash for principal plus accrued interest in the aggregate amount of $ 15.2 million. During the nine months ended September 30, 2022 , the Company recognized a loss of $ 0.1 million with respect to the change in fair value of the convertible promissory notes on the accompanying condensed consolidated statements of operations. On July 25, 2022, the Company issued a promissory note to PureTech in the principal amount of $ 15.0 million (see Note 12). At September 30, 2022 , the outstanding balance of the promissory note was $ 15.6 million recorded at fair value in the accompanying condensed consolidated balance sheets. During the three months ended September 30, 2022 , the Company recognized a loss of $ 0.6 million with respect to the change in the fair value of the promissory notes. SSD2 On December 13, 2021, the Company issued a convertible promissory note to SSD2 in the principal amount of $ 12.0 million (see Note 12). At December 31, 2021, the outstanding balance was $ 12.1 million, recorded at fair value in the accompanying condensed consolidated balance sheets. On January 19, 2022 the Company settled the convertible promissory notes in cash for principal plus accrued interest in the aggregate amount of $ 12.1 million. During the nine months ended September 30, 2022 , the Company recognized a loss of less than $ 0.1 million with respect to the change in fair value of the convertible promissory notes on the accompanying condensed consolidated statements of operations. On July 25, 2022, the Company issued a promissory note to SSD2 in the principal amount of $ 5.0 million (see Note 12). At September 30, 2022 , the outstanding balance of the promissory note was $ 5.2 million recorded at fair value in the accompanying condensed consolidated balance sheets. During the three months ended September 30, 2022 , the Company recognized a loss of $ 0.2 million with respect to the change in the fair value of the promissory notes. One S.r.l Consulting Agreement with Founder of One The Company and one of the founders of One, who is also a stockholder of the Company, entered into a consulting agreement for the development of the Company's science and technology. The Company incurred costs for consulting services received from the founder of One totaling less than $ 0.1 million during the three months ended September 30, 2022 and 2021, respectively, and $ 0.2 million during the nine months ended September 30, 2022 and 2021 , respectively, recorded in research and development expense in the accompanying condensed consolidated statements of operations. The Company recorded an accounts payable balance to the founder of less than $ 0.1 million at both September 30, 2022 and December 31, 2021, respectively, in the accompanying condensed consolidated balance sheets. Acquisition of One In connection with the amended and restated master agreement with One (see Note 11), the Company acquired a 10.0 % equity interest in One in exchange for cash consideration. During the nine months ended September 30, 2022 the Company made a payment of $ 2.9 million to One shareholders with respect to the acquisition . The Company had remaining undiscounted payments of € 2.5 million and € 5.0 million due to One at September 30, 2022 and December 31, 2021 , respectively (approximately $ 2.4 million and $ 5.7 million due to One at September 30, 2022 and December 31, 2021, respectively). The balance at September 30, 2022 was recorded in accrued expenses in the accompanying condensed consolidated balance sheets as it is expected to be settled within the next twelve months. Additionally, the Company incurred royalty expense of $ 0.1 million and $ 0.1 million with One (see Note 19) during the three months ended September 30, 2022 and 2021, respectively, and $ 0.4 million and $ 0.2 million during the nine months ended September 30, 2022 and 2021, respectively, recorded in cost of goods sold in the accompanying condensed consolidated statements of operations. The Company had an accounts payable balance to One S.r.l. of $ 0.2 million and an accrued expense balance of $ 0.1 million at September 30, 2022 and an accrued expense balance of less than $ 0.1 million at December 31, 2021, respectively, related to royalties in the accompanying condensed consolidated balance sheets. RIF Transaction In connection with the RIF transaction entered into in August 2020, the Company received $ 12.3 million from RIF as an equity investment that can be called by the Company beginning in December 2023 and ending in December 2026 by paying the investment plus 15.0 % percent annual interest or put by RIF starting in January 2027 and ending in December 2027 for the investment amount plus 3.175 % percent annual interest. RIF holds approximately 20 % of the equity of Gelesis S.r.l. at September 30, 2022 (see Note 11). In addition, the shareholders of RIF provided the Company with a loan for $ 18.4 million with a fixed interest rate of 6.35 % per annum (see Note 12).

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Event(s)	21. Subsequent Events The Company has evaluated subsequent events which may require adjustment to or disclosure in the condensed consolidated financial statements through the date of issuance of these condensed consolidated financial statements. On November 2, 2022, the Company received a letter from the NYSE indicating that the Company was not in compliance with the continued listing standard set forth in Rule 802.01C of the NYSE Listed Company Manual because the average closing price of our Common Stock fell below $ 1.00 per share over a period of 30 consecutive trading days (the “minimum share price requirement”). If the Company is unable to satisfy the NYSE requirement that its stock price return to a level over $1.00 by May 2, 2023 , the Company will be subject to the NYSE’s suspension and delisting procedures. The Company is closely monitoring the closing share price of its common stock and is considering all available options. The Company intends to regain compliance with the minimum share price requirement by pursuing measures that are in the best interest of the Company and its shareholders.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) issued by the Financial Accounting Standards Board (“FASB”). The Company consolidates those entities where it has a direct and indirect controlling financial interest based on either a variable interest model or voting interest model. The Company’s condensed consolidated financial statements include the accounts of the Company, its two wholly-owned subsidiaries and a variable interest entity (“VIE”), Gelesis S.r.l., in which the Company has a controlling interest and is the primary beneficiary. The noncontrolling interest attributable to the Company’s VIE is presented as a separate component from stockholders’ deficit in the condensed consolidated balance sheets and as a noncontrolling interest in the condensed consolidated statements of noncontrolling interest, redeemable convertible preferred stock and stockholders’ deficit. All intercompany balances and transactions have been eliminated in consolidation. Under the variable interest model, a controlling financial interest is determined based on which entity, if any, has (i) the power to direct the activities of the VIE that most significantly impacts the VIE’s economic performance and (ii) the obligations to absorb losses that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. Management performs ongoing reassessments of whether changes in the facts and circumstances regarding the Company’s involvement with a VIE will cause the consolidation conclusion to change. The consolidation status of a VIE may change as a result of such reassessments. Changes in consolidation status are applied prospectively in accordance with U.S. GAAP.
Reclassification of Prior Year Presentation	Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no effect on the reported results of operations or financial position.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. The Company assesses the above estimates on an ongoing basis; however, actual results could materially differ from those estimates.
Subsequent Event(s)	Subsequent Event(s) The Company considers events or transactions that occur after the balance sheet date but before the condensed consolidated financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. The Company evaluated all events and transactions through the date these condensed consolidated financial statements were filed with the Securities and Exchange Commission (“SEC”) or were available to be issued.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The guidance in FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”), defines fair value and establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 – Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Fair value is a market-based measure considered from the perspective of a market participant rather than an entity-specific measure. Therefore, even when market assumptions are not readily available, the Company’s own assumptions are set to reflect those that market participants would use in pricing the asset or liability at the measurement date. The Company uses prices and inputs that are current as of the measurement date, including during periods of market dislocation. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from Level 1 to Level 2 or Level 2 to Level 3. The Company’s earnout liability, private placement warrants, and call option liability are recorded at fair value on a recurring basis. The carrying amount of accounts receivable, grants receivable, accounts payable and accrued expenses are considered a reasonable estimate of their fair value, due to the short-term maturity of these instruments. The carrying amount of notes payable is also considered to be a reasonable estimate of the fair value based on the nature of the debt and that the debt bears interest at the prevailing market rate for instruments with similar characteristics. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above. Earnout Liability: In connection with the Business Combination, Legacy Gelesis Equityholders received the right to receive additional common stock upon the achievement of certain earnout targets. As the earnout consideration contains a settlement provision that precludes it from being indexed to the Company’s stock, it is classified as a liability held at fair value in accordance ASC 815 and the instrument is adjusted to fair value at each reporting period. In determining the fair value of the earnout liability at inception and on a recurring basis, the Company utilizes the Monte Carlo simulation value model where the fair value of the earnout is the present value of a distribution of potential outcomes on a daily basis over the term of the earnout period. Private Placement Warrant Liability: The Private Placement Warrants are recognized as liabilities in accordance with ASC 815. Accordingly, the Company recognizes the warrant instruments as liabilities held at fair value and adjusts the instruments to fair value at each reporting period. In determining the fair value of the Private Placement Warrant liability, the Company utilized a modified Monte Carlo simulation value model at inception and on a recurring basis. One S.r.l. Call Option: In connection with the October 2020 amended agreement with One S.r.l., the Company granted One a contingent call option to buy back the 10 % ownership that the Company acquired in the 2019 One Amendment. The One S.r.l. call option was recorded as a liability held at fair value at the date of issuance and is remeasured at each subsequent reporting date with changes in fair value recorded in other income (expense) in the accompanying condensed consolidated statements of operations. Fair value is determined using a Black-Scholes option pricing model. Convertible promissory notes: The convertible promissory notes issued in conjunction with the Company’s bridge financing arrangements from time to time were recognized at fair value at issuance and subsequent changes in fair value were recorded in the accompanying consolidated statements of operations (see Note 12). Fair value of the promissory notes is determined using a multiple scenario-based valuation method. The fair value of the hybrid instrument was determined by calculating the value of the instrument in each scenario “with” the respective conversion feature and “without”. The significant inputs used in estimating the fair value of the convertible promissory notes include the estimated discount rate, expected term, and the outcome probability with respect to each scenario.
Revenue Recognition	Revenue Recognition Product Revenue The Company commercializes Plenity in the U.S. markets principally through synergistic partnerships with online pharmacies and telehealth providers, which in turn sell Plenity directly to patients based on prescriptions. Outside the U.S., the Company primarily seeks collaborations with strategic partners to market Plenity and obtain necessary regulatory approvals as necessary. Product revenue is recognized by the Company in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services when the customer obtains control of the product, which occurs at a point in time, when the product is received by the Company's customers. Reserves for Variable Consideration Revenues from product sales are recorded as product revenue at the net sales price (transaction price), which includes estimates of variable consideration that are reimbursable to customers for which reserves are established and which result from (a) shipping charges to end-users, (b) pharmacy dispensing and platform fees, (c) merchant and processing fees, (d) promotional discounts offered by the Company to end-users, and (e) reserves for expected product quality returns. These reserves for contractual adjustments are based on the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable (if the amount is payable to the customer) or a current liability (if the amount is payable to a party other than the customer). Where appropriate, these estimates take into consideration a range of possible outcomes that are probability-weighted for relevant factors such as the Company's historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company's best estimates of the amount of consideration to which the Company is entitled based on the terms of the contract(s). The amount of variable consideration that is included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts of consideration ultimately received may differ from the Company's estimates. If actual results in the future vary from the Company's estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. The Company has no plan to seek government or commercial payor reimbursements in the US or the overseas markets. Therefore, reserves for variable consideration do not contain any components related to government and payor rebates or chargebacks. Product Returns The Company generally does not accept customer returns, except for product quality related cases. The Company evaluates quality related returns and adjusts the corresponding product warranty reserves and liabilities at least quarterly and at the end of each reporting period.
Stock-Based Compensation	Stock-Based Compensation Effective January 1, 2020, the Company accounts for all stock-based compensation awards granted to employees and non-employees in accordance with ASC 718, Compensation – Stock Compensation . The Company’s stock-based compensation consist primarily of stock options. The measurement date for share-based awards is the date of grant, and stock-based compensation costs are recognized as expense over the respective requisite service periods, which are typically the vesting period. The fair value of each stock option grant is estimated as of the date of grant using the Black-Scholes option-pricing model that requires management to apply judgment and make estimates, including: • exercise price: The exercise price is the fair market value on grant date, which shall mean the closing sale price of common stock, as reported on such market on that date (or if there are no market quotations for such date, the determination shall be made by reference to the last date preceding such date for which there are market quotations); • expected volatility: As the Company was previously a privately-owned company, there is not sufficient historical volatility for the expected term of the options. Therefore, the Company used an average historical share price volatility based on an analysis of reported data for a peer group of comparable companies for which historical information is available. For these analyses, the Company selects companies with comparable characteristics to itself including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The Company computes the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of its stock-based awards. The Company intends to consistently apply this process using representative companies until a sufficient amount of historical information regarding the volatility of its own share price becomes available; • risk-free interest rate, which is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption; • expected term, which is calculated using the simplified method, as prescribed by the Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment, as the Company has insufficient historical information regarding its stock options to provide a basis for an estimate. Under this approach, the weighted-average expected life is presumed to be the average of the contractual term of ten years and the weighted-average vesting term of the stock options, taking into consideration multiple vesting tranches; • dividend yield, which is zero based on the fact that the Company never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. Since the adoption of ASU 2018-07 on January 1, 2020, the measurement date for non-employee awards is the date of grant without changes in the fair value of the award. Stock-based compensation costs for non-employees are recognized as expense over the vesting period. Stock-based compensation expense is classified in the condensed consolidated statements of operations based on the function to which the related services are provided. Forfeitures are recorded as they occur.

Business Combination and Reve_2

Business Combination and Reverse Recapitalization (Tables)	9 Months Ended
	Sep. 30, 2022
Business Combination and Reverse Recapitalization [Abstract]
Summary of Net Proceeds from Business Combination	The following table summarizes the net proceeds from the Business Combination, as reconciled to the accompanying condensed consolidated statements of noncontrolling interest, redeemable convertible preferred stock and stockholder’s equity (deficit) and the condensed consolidated statements of cash flows: Amount Cash - CPSR trust and cash (net of redemptions) $ 7,558 Cash - PIPE Investment 90,000 Cash - Backstop Agreement 7,442 Gross proceeds $ 105,000 Less: transaction costs, advisory fees and liabilities paid ( 34,522 ) Net proceeds from the Business Combination $ 70,478
Schedule of Number of Shares Issued and Immediately Consummation of Business Combination	The number of shares of common stock issued and outstanding immediately following the consummation of the Business Combination was as follows: Common Stock CPSR Public Stockholders 755,223 CPSR Sponsor Stockholders 4,916,250 Total CPSR Stockholders 5,671,473 Common stock issued to Gelesis Legacy Equityholders 54,814,847 Common stock issued to PIPE Investors and Backstop Agreement 11,727,967 Total common stock immediately after Closing 72,214,287

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Schedule of Liabilities Measured at Fair Value on Recurring Basis	Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at September 30, 2022 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Asset: Interest rate swap contract (see Note 12) $ 702 $ — $ 702 $ — Liabilities: Convertible promissory notes (see Note 12) 25,852 — — 25,852 Earnout liability (See Note 14) 3,376 — — 3,376 Private placement warrant liability (see Note 13) 590 — — 590 One S.r.l. call option 1,244 — — 1,244 Total liabilities measured at fair value $ 31,062 $ — $ — $ 31,062 Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at December 31, 2021 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Liabilities: Convertible promissory notes (see Note 12) $ 27,128 $ — $ — $ 27,128 Legacy Gelesis preferred stock warrants (See Note 13) 15,821 — — 15,821 One S.r.l. call option 2,416 — — 2,416 Total liabilities measured at fair value $ 45,365 $ — $ — $ 45,365
Summary of Changes in Fair Value of Company's Level 3 Financial Instruments	The following table presents a summary of the changes in the fair value of the Company’s Level 3 financial instruments during the nine months ended September 30, 2022: Convertible Promissory Notes Legacy Gelesis Redeemable Preferred Stock Warrants Liabilities One S.r.l. Call Option Earnout Liability Private Placement Warrant Liability Balance at December 31, 2021 $ 27,128 $ 15,821 $ 2,416 $ — $ — Assumed upon Business Combination — — — — 8,140 Recognized upon Business Combination — — — 58,871 — Issuance of convertible promissory notes 25,000 — — — — Changes in fair value 1,008 926 ( 808 ) ( 55,495 ) ( 7,550 ) Foreign currency translation adjustment — — ( 364 ) — — Conversion and exchange upon Business Combination — ( 16,747 ) — — — Settlement ( 27,284 ) — — — — Balance at September 30, 2022 $ 25,852 $ — $ 1,244 $ 3,376 $ 590

Product Revenue and Reserve a_2

Product Revenue and Reserve and Allowances (Tables)	9 Months Ended
	Sep. 30, 2022
Revenue From Contract With Customer [Abstract]
Summary of Revenue	Revenue for the three and nine months ended September 30, 2022 and 2021 consisted of the following (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Roman Health Pharmacy LLC $ 4,793 $ 2,810 $ 18,208 $ 7,741 GoGoMeds 1,650 204 4,722 434 CMS — — — 118 Total $ 6,443 $ 3,014 $ 22,930 $ 8,293
Summary of Activity in Product Revenue Reserve and Allowance	The following table summarizes the activity in the product revenue reserve and allowance during the nine months ended September 30, 2022 and 2021 (in thousands): 2022 2021 Balance at December 31, $ 82 $ 14 Provision related to product sales 1,595 376 Credits and payments made ( 1,653 ) ( 365 ) Balance at September 30, $ 24 $ 25

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2022
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): September 30, December 31, 2022 2021 Raw materials $ 9,027 $ 8,074 Work in process 4,467 2,643 Finished goods 4,917 2,786 Total inventories $ 18,411 $ 13,503

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2022
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2022 2021 Prepaid expenses $ 566 $ 982 Prepaid insurance 965 55 Prepaid manufacturing expenses 281 2,624 Prepaid contract research costs 173 262 Research and development tax credit 649 579 Value added tax receivable 2,411 5,633 Deferred financing costs — 3,855 Income tax receivable 186 213 Investment tax credit 645 — Prepaid expenses and other current assets $ 5,876 $ 14,203

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2022
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): September 30, December 31, 2022 2021 Laboratory and manufacturing equipment $ 27,337 $ 28,101 Land and buildings 9,695 10,404 Leasehold improvements 1,399 1,614 Computer equipment and software 512 463 Capitalized software 232 228 Construction in process 22,495 22,097 Property and equipment – at cost 61,670 62,907 Less accumulated depreciation ( 6,518 ) ( 4,392 ) Property and equipment – net $ 55,152 $ 58,515

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2022
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Accrued payroll and related benefits $ 2,921 $ 1,384 Accrued professional fees and outside contractors (including 128 and $ 60 , respectively) 4,482 4,359 Accrued property, plant and equipment additions 481 1,257 Accrued inventory and manufacturing expense 362 128 Unpaid portion of acquisition of intangible asset and 2,412 5,604 Tax payables 26 145 Deferred legal fees 738 738 Accrued interest 834 45 Total accrued expenses $ 12,256 $ 13,660

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Other Liabilities Disclosure [Abstract]
Other Long-Term Liabilities	Other long-term liabilities consisted of the following (in thousands): September 30, December 31, 2022 2021 Long-term tax liabilities $ 85 $ 182 Contingent loss for research and development tax credits 2,583 2,990 One S.r.l. call option (see Note 11) 1,244 2,416 Total other long-term liabilities $ 3,912 $ 5,588

Significant Agreements (Tables)

Significant Agreements (Tables)	9 Months Ended
	Sep. 30, 2022
Significant Agreements [Abstract]
Schedule of Finite Lived Intangible Assets Amortization Expense	A summary of the intangible asset activity that resulted from this transaction during the nine months ended September 30, 2022 is as follows (in thousands): Intangible Assets Intangible asset at relative fair value $ 15,564 Adjustment to record deferred tax liability 5,783 Carrying value of intangible asset at June 2019 acquisition date 21,347 Cumulative amortization expense ( 5,667 ) Balance at December 31, 2021 $ 15,680 Period amortization expense ( 1,700 ) Balance at September 30, 2022 $ 13,980
Summary of Changes in Fair Value of Call Option Liability	The following represents a summary of the changes to Company’s One S.r.l. call option liability during the nine months ended September 30, 2022 (in thousands): Balance at December 31, 2021 $ 2,416 Change in fair value ( 808 ) Foreign currency translation gain ( 364 ) Balance at September 30, 2022 $ 1,244
Weighted Average Assumptions Used to Determine Fair Value of Call Option Liability	The following weighted average assumptions were used to determine the fair value of the One S.r.l. call option liability at September 30, 2022 and December 31, 2021: September 30, December 31, 2022 2021 Expected term 4.0 years 2.0 years Expected volatility 75.0 % 62.0 % Expected dividend yield 0.0 % 0.0 % Risk free interest rate 4.3 % 0.70 % Estimated fair value of ownership interest $ 2,928 $ 6,922 Exercise price of call option $ 5,879 $ 6,806

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Summary of Non-Convertible Debt Outstanding	The Company’s non-convertible debt outstanding at September 30, 2022 and December 31, 2021 is summarized as follows: September 30, December 31, 2022 2021 Italian Economic Development Agency Loan 303 525 Intesa Sanpaolo Loan 1 6,709 8,507 Intesa Sanpaolo Loan 2 4,899 5,672 Horizon 2020 Loan 388 486 RIF Shareholders Loan 14,698 17,015 UniCredit Loan 4,863 5,630 Total debt obligation $ 31,860 $ 37,835 Unamortized loan discount and issuance costs ( 895 ) ( 754 ) Total debt obligation carrying amount $ 30,965 $ 37,081 Current portion $ 4,249 $ 1,950 Long-term portion $ 26,716 $ 35,131
Summary of Assumptions Used to Determine Fair Value of 2022 Convertible Promissory Notes	The following assumptions were used to determine the fair value of the 2022 convertible promissory notes at September 30, 2022: At September 30, 2022 Expected term 1.25 years Weighted average discount rate 26.0 % Probability of repayment after qualified financing 50.0 % Probability of holder electing conversion option 50.0 %
Summary of Future Maturities to Debt Outstanding	Future maturities with respect to debt outstanding at September 30, 2022 are as follows (in thousands): At September 30, 2022 Remaining 2022 obligation $ 1,063 2023 33,268 2024 4,985 2025 3,627 2026 3,646 More than 5 years 11,123 Total maturities $ 57,712

Warrant Liabilities (Tables)

Warrant Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Class Of Warrant Or Right [Line Items]
Summary of Changes in Warrant Liabilities Activity	The following represents a summary of the warrant liabilities activity during the nine months ended September 30, 2022: Series A-4 Private Placement Warrants Total Balance at December 31, 2021 $ 15,821 $ — $ 15,821 Assumed upon Business Combination — 8,140 8,140 Changes in fair value 926 ( 7,550 ) ( 6,624 ) Conversion and exchange upon Business Combination ( 16,747 ) — ( 16,747 ) Balance at September 30, 2022 $ — $ 590 $ 590
Summary of Weighted Average Assumptions of Fair Value of Liabilities	Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at September 30, 2022 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Asset: Interest rate swap contract (see Note 12) $ 702 $ — $ 702 $ — Liabilities: Convertible promissory notes (see Note 12) 25,852 — — 25,852 Earnout liability (See Note 14) 3,376 — — 3,376 Private placement warrant liability (see Note 13) 590 — — 590 One S.r.l. call option 1,244 — — 1,244 Total liabilities measured at fair value $ 31,062 $ — $ — $ 31,062 Liabilities that are measured at fair value on a recurring basis, and the level of the fair value hierarchy utilized to determine such fair values, consisted of the following at December 31, 2021 (in thousands): Fair Value Measurements Fair Value Quoted Prices Significant Significant Liabilities: Convertible promissory notes (see Note 12) $ 27,128 $ — $ — $ 27,128 Legacy Gelesis preferred stock warrants (See Note 13) 15,821 — — 15,821 One S.r.l. call option 2,416 — — 2,416 Total liabilities measured at fair value $ 45,365 $ — $ — $ 45,365
Private Placement Warrants
Class Of Warrant Or Right [Line Items]
Summary of Weighted Average Assumptions of Fair Value of Liabilities	The following weighted-average assumptions were used to determine the fair value of the Private Placement Warrant liability at September 30, 2022: Private Placement Warrants Expected term 4.3 years Expected volatility 66.0 % Expected dividend yield 0.0 % Risk free interest rate 4.0 % Price of Gelesis Common Stock $ 1.08 Exercise price of warrants $ 11.50

Earnout Liability (Tables)

Earnout Liability (Tables)	9 Months Ended
	Sep. 30, 2022
Derivative Instrument Detail [Abstract]
Summary of Earnout Liability Activity	The following represents a summary of the earnout liability activity during the nine months ended September 30, 2022: Earnout Liability Balance at December 31, 2021 $ — Recognized upon Business Combination 58,871 Changes in fair value ( 55,495 ) Balance at September 30, 2022 $ 3,376
Summary of Weighted Average Assumptions Used to Determine Fair Value of Earnout Liability	The following weighted-average assumptions were used to determine the fair value of the earnout liability at September 30, 2022: Earnout Liability Expected term 4.3 years Expected volatility 66.0 % Expected dividend yield 0.0 % Risk free interest rate 4.0 % Price of Gelesis Common Stock $ 1.08

Stockholder's Equity (Deficit)

Stockholder's Equity (Deficit) (Tables)	9 Months Ended
	Sep. 30, 2022
Stockholders Equity Note [Abstract]
Schedule of Common Stock Reserved for Future Issuance	At September 30, 2022 and December 31, 2021 common stock reserved for future issuances was as follows: September 30, December 31, 2022 2021 Common stock issued upon option exercise and RSUs vesting 18,694,129 13,486,708 Conversion of all classes of redeemable convertible — 48,566,655 Issuances upon exercise of warrants to purchase Series A-4, — 1,836,429 Issuances upon exercise of common stock warrants 24,733,365 1,353,062 Earnout shares 23,482,845 — Total common stock reserved for future issuance 66,910,339 65,242,854

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-Based Compensation Expense	Stock-based compensation expense is summarized for employees and nonemployees, by category in the accompanying condensed consolidated statements of operations as follows (in thousands): For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 Research and development $ 1,058 $ 243 $ 9,131 $ 1,304 Selling, general and administrative 3,516 843 17,408 2,876 Total $ 4,574 $ 1,086 $ 26,539 $ 4,180
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity during the nine months ended September 30, 2022: Number of Weighted- Weighted- Aggregate Outstanding at December 31, 2021 4,889,820 $ 10.39 6.17 $ 54,449 Retroactive application of reverse recapitalization 7,784,666 ( 6.38 ) Adjusted and Outstanding at December 31, 2021 12,674,486 $ 4.01 6.17 $ 54,449 Granted 2,658,185 $ 3.35 Exercised ( 162,064 ) $ 0.68 Forfeited - unvested ( 548,653 ) $ 5.23 Forfeited - vested ( 63,718 ) $ 4.31 Expired ( 456,534 ) $ 1.23 Outstanding at September 30, 2022 14,101,702 $ 3.96 6.31 $ 502 Exercisable at September 30, 2022 10,218,998 $ 3.89 5.30 $ 502 Vested and Expected to Vest at September 30, 2022 14,101,702 $ 3.96 6.31 $ 502
Schedule of Grant Date Fair Value of Options Issued Using Black-Scholes Weighted Average Assumptions	The fair value of each option issued was estimated at the date of grant using Black-Scholes with the following weighted-average assumptions: For the Nine Months Ended September 30, 2022 Market price of common stock $ 3.35 Expected volatility 72.4 % Expected term (in years) 6.1 Risk-free interest rate 1.7 % Expected dividend yield 0.0 %
Summary of Restricted Stock Unit Activity	The following table summarizes the Company’s RSU activity during the nine months ended September 30, 2022: Number of RSUs Weighted- Outstanding and Unvested at December 31, 2021 313,354 $ 21.41 Retroactive application of reverse recapitalization 498,868 $ ( 13.15 ) Adjusted and Outstanding and Unvested at December 31, 2021 812,222 $ 8.26 Granted 4,555,197 $ 3.46 Vested ( 41,404 ) $ 6.77 Forfeited ( 640,849 ) $ 3.35 Outstanding and Unvested at September 30, 2022 4,685,166 $ 4.28

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Summary of Basic and Diluted Net Loss Per Share	Basic and diluted loss per share attributable to common stockholders was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Numerator: Net loss $ ( 14,149 ) $ ( 30,730 ) $ ( 32,365 ) $ ( 74,055 ) Accretion of redeemable convertible preferred stock to redemption value — ( 23,111 ) ( 37,934 ) ( 139,237 ) Accretion of noncontrolling interest put option to redemption value ( 80 ) ( 95 ) ( 253 ) ( 285 ) Net loss attributable to common stockholders $ ( 14,229 ) $ ( 53,936 ) $ ( 70,552 ) $ ( 213,577 ) Denominator: Weighted average common shares outstanding, basic and diluted 72,772,627 5,615,192 69,349,679 5,592,931 Net loss per share, basic and diluted $ ( 0.20 ) $ ( 9.61 ) $ ( 1.02 ) $ ( 38.19 )
Schedule of Anti-dilutive Securities Excluded from Computation of Net Loss Per Share	The Company excluded the following potential common stock, presented based on amounts outstanding at September 30, 2022 and 2021 from the computation of diluted net loss per share attributable to common stockholders because including them would have had an anti-dilutive effect. September 30, 2022 2021 Convertible preferred stock — 48,566,655 Warrants on convertible preferred stock — 1,836,429 Options and RSUs to acquire common stock 18,694,129 13,555,474 Warrants on common stock 24,733,365 1,353,062 Earnout shares — — Total 43,427,494 65,311,620

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Maturities of the Lease Liability Under the Company's Noncancelable Operating Leases	Future maturities of the lease liability under the Company’s noncancelable operating leases at September 30, 2022 are as follows (in thousands): At September 30, 2022 Remaining 2022 maturities $ 163 2023 649 2024 567 2025 381 2026 29 More than 5 years 13 Total undiscounted lease maturities $ 1,802 Imputed interest ( 129 ) Total lease liability $ 1,673

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details) - Gelesis $ in Millions	Jan. 13, 2022 USD ($)
Subsidiary Sale Of Stock [Line Items]
Gross proceeds from business combinations	$ 105
Net proceeds from business combinations	$ 70.5

Summary of Significant Accoun_3

Summary of Significant Accounting Policies-Additional Information (Details) - One Srl	Sep. 30, 2022	Aug. 09, 2022	Jun. 30, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Equity Method Investment Ownership Percentage		10%	10%
Call Option
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Equity Method Investment Ownership Percentage	10%

Business Combination and Reve_3

Business Combination and Reverse Recapitalization - Additional Information (Details) $ / shares in Units, $ in Thousands		9 Months Ended	12 Months Ended
	Jan. 13, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Jan. 31, 2022 $ / shares
Business Acquisition [Line Items]
Common stock, shares issued | shares		72,983,488	6,248,192
Common stock, par value | $ / shares		$ 0.0001	$ 0.0001
Aggregate purchase price		$ 39
Common stock exchange ratio	2.59
Number of earn-out shares contingent consideration arrangement | shares	18,758,241
Liability upon the closing of business combination	$ 58,900
Number of remaining earn out shares | shares	4,724,604
Fair value of incremental compensation cost	$ 14,800
Business combination, aggregate transaction costs	$ 37,200
Public Warrants
Business Acquisition [Line Items]
Number of warrants outstanding | shares	13,800,000
Carrying value of warrants transferred to additional paid in capital	$ 7,100
Private Placement Warrants
Business Acquisition [Line Items]
Number of warrants outstanding | shares	7,520,000
Liability held at fair value	$ 8,100
Research and Development Expense
Business Acquisition [Line Items]
Fair value of incremental compensation cost	4,400
PIPE Investors
Business Acquisition [Line Items]
Aggregate purchase price	90,000
CPSR
Business Acquisition [Line Items]
Business combination, direct transaction costs	22,300
Business combination, liabilities assumed	$ 9,500
Backstop Agreement
Business Acquisition [Line Items]
Aggregate purchase price			$ 7,400
Gelesis
Business Acquisition [Line Items]
Number of restricted earn out shares entitled | shares	23,482,845
Trading price for future vesting threshold of the first third | $ / shares	$ 12.50
Trading price for future vesting threshold of the second third | $ / shares	15
Trading price for future vesting threshold of the third portion | $ / shares	$ 17.50
Number of trading days within specified period that share price must exceed	20 days
Consecutive trading days used to evaluate share price	30 days
Threshold period before share price condition commences	5 years
Fair value of incremental compensation cost	$ 11,400
Business combination, direct transaction costs	5,400
Business combination, transaction costs allocated to earnout shares	2,700
Gelesis | Selling, General and Administrative Expense
Business Acquisition [Line Items]
Fair value of incremental compensation cost	$ 7,000
Class A common stock | Backstop Agreement
Business Acquisition [Line Items]
Common stock, shares issued | shares			1,983,750
Class A common stock | Private Placement | PIPE Investors
Business Acquisition [Line Items]
Common stock, shares issued | shares	9,000,000
Common stock, par value | $ / shares				$ 10
Class A common stock | Private Placement | Backstop Agreement
Business Acquisition [Line Items]
Common stock, shares issued | shares			744,217
Common stock, par value | $ / shares			$ 10
Common Stock
Business Acquisition [Line Items]
Common stock, shares issued | shares		72,983,488
Common stock, par value | $ / shares		$ 0.0001
Common Stock | Gelesis
Business Acquisition [Line Items]
Common stock exchange ratio	2.59
Convertible preferred stock exchange ratio	2.59
Stock options and restricted stock units conversion exchange ratio	2.59
Preferred stock warrants conversion exchange ratio	2.59
Common stock warrants conversion exchange ratio	2.59

Business Combination and Reve_4

Business Combination and Reverse Recapitalization - Summary of Net Proceeds from Business Combination (Details) $ in Thousands	Jan. 13, 2022 USD ($)
Business Acquisition [Line Items]
Gross Proceeds	$ 105,000
Less: transaction costs, advisory fees and liabilities paid	(34,522)
Net proceeds from the Business Combination	70,478
Capstar Special Purpose Acquisition Corp [Member]
Business Acquisition [Line Items]
Gross Proceeds	7,558
PIPE Investors
Business Acquisition [Line Items]
Gross Proceeds	90,000
Backstop Agreement
Business Acquisition [Line Items]
Gross Proceeds	$ 7,442

Business Combination and Reve_5

Business Combination and Reverse Recapitalization - Schedule of Consummation of Business Combination (Details) - shares	9 Months Ended
	Sep. 30, 2022	Jan. 13, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Total common stock immediately after Closing	72,983,488		6,248,192
Common Stock
Business Acquisition [Line Items]
CPSR stockholders	5,671,473
Common stock issued to Gelesis Legacy Equityholders	54,814,847
Common stock issued to PIPE investors and backstop agreement	11,727,967
Total common stock immediately after Closing	72,983,488	72,214,287
Common Stock | CPSR Public Stockholders
Business Acquisition [Line Items]
CPSR stockholders	755,223
Common Stock | CPSR Sponsor Stockholders
Business Acquisition [Line Items]
CPSR stockholders	4,916,250

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Liabilities Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Liabilities
Convertible promissory notes (see Note 12)	$ 25,852	$ 27,128
Legacy Gelesis preferred stock warrants (See Note 13)		15,821
One S.r.l call option (see Note 11)	1,244	2,416
Total liabilities measured at fair value	31,062	45,365
Level 3
Liabilities
Convertible promissory notes (see Note 12)	25,852	27,128
Legacy Gelesis preferred stock warrants (See Note 13)		15,821
One S.r.l call option (see Note 11)	1,244	2,416
Total liabilities measured at fair value	31,062	$ 45,365
Interest Rate Swap Contract
Liabilities
Interest rate swap contract (see Note 12)	702
Interest Rate Swap Contract | Level 2
Liabilities
Interest rate swap contract (see Note 12)	702
Earnout Liability
Liabilities
Earnout liability (See Note 14)	3,376
Earnout Liability | Level 3
Liabilities
Earnout liability (See Note 14)	3,376
Private Placement Warrant Liability
Liabilities
Warrant liability	590
Private Placement Warrant Liability | Level 3
Liabilities
Warrant liability	$ 590

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Changes in Fair Value of Company's Level 3 Financial Instruments (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 15,821
Assumed upon Business Combination	8,140
Change in fair value	(6,624)
Conversion and exchange upon Business Combination	(16,747)
Balance	590
Convertible Promissory Notes | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	27,128
Issuance of convertible promissory notes	25,000
Change in fair value	1,008
Settlement	27,284
Balance	25,852
Legacy Gelesis Preferred Stock Warrants | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	15,821
Change in fair value	926
Conversion and exchange upon Business Combination	16,747
One S.r.l. Call Option | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	2,416
Change in fair value	(808)
Foreign currency translation adjustment	(364)
Balance	1,244
Earnout Liability | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Recognized upon Business Combination	58,871
Change in fair value	(55,495)
Balance	3,376
Private Placement Warrant Liability | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Assumed upon Business Combination	8,140
Change in fair value	(7,550)
Balance	$ 590

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	9 Months Ended
	Sep. 30, 2022 USD ($)
Fair Value, Transfers Between Level 1 and Level 2, Description and Policy [Abstract]
Liabilities, Transfer from Level 1 to Level 2	$ 0
Liabilities, Transfer from Level 2 to Level 1	0
Liabilities, Transfer into Level 3	0
Liabilities, Transfer out of Level 3	$ 0

Product Revenue and Reserve a_3

Product Revenue and Reserve and Allowances - Summary of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Product Information [Line Items]
Revenue	$ 6,652	$ 3,014	$ 23,139	$ 8,293
Product Revenue, Net
Product Information [Line Items]
Revenue	6,443	3,014	22,930	8,293
Product Revenue, Net | Roman Health Pharmacy LLC
Product Information [Line Items]
Revenue	4,793	2,810	18,208	7,741
Product Revenue, Net | GoGoMeds
Product Information [Line Items]
Revenue	$ 1,650	$ 204	$ 4,722	434
Product Revenue, Net | CMS
Product Information [Line Items]
Revenue				$ 118

Product Revenue and Reserve a_4

Product Revenue and Reserve and Allowances - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Aug. 04, 2022	Jun. 14, 2022	Dec. 31, 2021
Product Information [Line Items]
Accounts receivable	$ 775		$ 775				$ 731
Warrants to purchase common stock	24,733,365		24,733,365				1,353,062
Common stock, par value	$ 0.0001		$ 0.0001				$ 0.0001
Revenue	$ 6,652	$ 3,014	$ 23,139	$ 8,293
Additional paid-in capital	295,333		295,333				$ (64,549)
CMS Amendment
Product Information [Line Items]
Additional paid-in capital	600		600
CMS Bridging DMCC | CMS Amendment
Product Information [Line Items]
One-time regulatory approval milestone payment					$ 5,000
Warrants to purchase common stock					400,000
Common stock, par value					$ 0.0001
Exercise price of warrants					$ 0.01
CMS Bridging DMCC | CMS Amendment | Other Assets
Product Information [Line Items]
Discounted one-time regulatory approval milestone payment					$ 4,200		4,100
Product Revenue, Net
Product Information [Line Items]
Revenue	6,443	3,014	22,930	8,293
Product Revenue, Net | Roman Health Pharmacy LLC
Product Information [Line Items]
Revenue	4,793	2,810	18,208	7,741
Product Revenue, Net | Roman Health Pharmacy LLC | Current Liabilities
Product Information [Line Items]
Deferred income	27,700		27,700				31,000
Product Revenue, Net | Roman Health Pharmacy LLC | Third Amended and Restated Supply and Distribution Agreement
Product Information [Line Items]
Deferred income						$ 15,000
Product Revenue, Net | GoGoMeds
Product Information [Line Items]
Accounts receivable	800		800				$ 800
Revenue	1,650	$ 204	4,722	434
Product Revenue, Net | CMS Bridging DMCC
Product Information [Line Items]
Revenue				$ 118
Licensing Revenue
Product Information [Line Items]
Revenue	209		$ 209
Licensing Revenue | CMS Amendment
Product Information [Line Items]
Revenue	$ 200

Product Revenue and Reserve a_5

Product Revenue and Reserve and Allowances - Summary of Activity in Product Revenue Reserve and Allowance (Details) - Product Revenue, Net - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Product Information [Line Items]
Product revenue reserve and allowance, beginning balance	$ 82	$ 14
Provision related to product sales	1,595	376
Credits and payments made	(1,653)	(365)
Product revenue reserve and allowance, ending balance	$ 24	$ 25

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 9,027	$ 8,074
Work in process	4,467	2,643
Finished goods	4,917	2,786
Total inventories	$ 18,411	$ 13,503

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid expenses	$ 566	$ 982
Prepaid Insurance	965	55
Prepaid manufacturing expenses	281	2,624
Prepaid contract research costs	173	262
Research and development tax credit	649	579
Value added tax receivable	2,411	5,633
Deferred financing costs	0	3,855
Income tax receivable	186	213
Investment tax credit receivable	645	0
Prepaid expenses and other current assets	$ 5,876	$ 14,203

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	$ 61,670	$ 62,907
Less accumulated depreciation	(6,518)	(4,392)
Property and equipment – net	55,152	58,515
Laboratory And Manufacturing Equipment
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	27,337	28,101
Land And Buildings
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	9,695	10,404
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	1,399	1,614
Computer Equipment and Software
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	512	463
Capitalized Software
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	232	228
Construction in Process
Property, Plant and Equipment [Line Items]
Property and equipment - at cost	$ 22,495	$ 22,097

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) ft² a	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) ft² a	Sep. 30, 2021 USD ($)
Property Plant And Equipment [Abstract]
Area of facility under manufacturing and research and development	51,000		51,000
Area of facility under manufacturing and research and development expects to expand	88,600		88,600
Area of land | a	12		12
Additional area of facility initiated for construction	207,000		207,000
Depreciation | $	$ 300	$ 200	$ 2,133	$ 591

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued payroll and related benefits	$ 2,921	$ 1,384
Accrued professional fees and outside contractors (including due to related party of $128 and $60, respectively)	4,482	4,359
Accrued property, plant and equipment additions	481	1,257
Accrued inventory and manufacturing expense	362	128
Unpaid portion of acquisition of intangible asset and investment in related party (see Note 11)	2,412	5,604
Tax payable	26	145
Deferred legal fees	738	738
Accrued interest	834	45
Total accrued expenses	$ 12,256	$ 13,660

Accrued Expenses - Summary of_2

Accrued Expenses - Summary of Accrued Expenses and Other Current Liabilities (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued Professional fee, due to related party	$ 128	$ 60

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Long-term tax liabilities	$ 85	$ 182
Contingent loss for research and development tax credits	2,583	2,990
One S.r.l. call option (see Note 11)	1,244	2,416
Total other long-term liabilities	$ 3,912	$ 5,588

Significant Agreements - Additi

Significant Agreements - Additional Information (Details) $ / shares in Units, € in Millions, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended
	Oct. 31, 2020 EUR (€)	Aug. 31, 2020 EUR (€)	Sep. 30, 2022 USD ($) $ / shares	Sep. 30, 2022 USD ($) $ / shares	Sep. 30, 2021 USD ($)	Sep. 30, 2022 EUR (€)	Aug. 09, 2022 USD ($) $ / shares shares	Aug. 09, 2022 EUR (€) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Jun. 30, 2019
One S.r.l
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Class of Warrant or Right, Outstanding | shares							1,353,062	1,353,062
One
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Equity interest acquired (as a percent)							10%	10%			10%
Cash consideration			$ 2.9	$ 2.9
Remaining undiscounted payments due			2.4	2.4		€ 2.5			$ 5.7	€ 5
Deferred payment of remaining purchase price							$ 2.4	€ 2.5
Loss due to the amendment to the Warrant Purchase Agreement			0.3
Research Innovation Fund Financing
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from RIF		€ 10		$ 9.8
Interest rate		6.35%
Investments interest rate		15%
Annual interest rate in connection with transaction		3.175%
Long term debt term		8 years
Period of subsequent issuance		24 months
Equity interest held by related party				20%
Accretion of noncontrolling interest			0.3	$ 0.3
Foreign currency translation gain				1.6
Noncontrolling interest			10.5	10.5					11.9
Debt		€ 15	$ 14.7	$ 14.7
Minimum | One S.r.l
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Exercise price of warrants | $ / shares							$ 1.45
Maximum | One S.r.l
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Exercise price of warrants | $ / shares			$ 4.26	$ 4.26
Call Option | One
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Equity interest acquired (as a percent)			10%	10%		10%
Exercise price of call option to buy back ownership percentage	€ 6			$ 5.9
Puglia1 Grant
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Other income				0.6	$ 0.5
Grant funding for certain facility and equipment investments				0.5
Deferred income			$ 5	5					6.4
Deferred income, current liability			0.7	0.7					0.9
Grant proceeds collected				0
Grants receivable			4.7	4.7					5.4
Puglia1 Grant | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grant funding for certain research and development expenditures				0.1
Grant funding for certain facility and equipment investments					0.2
Puglia 2 Grant
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Other income				1.3	$ 1
Deferred income			3.2	3.2					3.7
Deferred income, current liability			0.3	0.3					0.4
Grant proceeds collected				0
Grants receivable			$ 4.3	$ 4.3					$ 3.6

Significant Agreements - Schedu

Significant Agreements - Schedule of Finite Lived Intangible Assets Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2019	Sep. 30, 2022	Sep. 30, 2021	Jun. 01, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Intangible asset at relative fair value						$ 15,564
Adjustment to record deferred tax liability			$ 5,783
Cumulative amortization expense			(5,667)
Intangible asset, beginning balance				$ 15,680
Amortization expense	$ (567)	$ (567)		(1,700)	$ (1,700)
Intangible asset, ending balance	$ 13,980		$ 21,347	$ 13,980

Significant Agreements - Summar

Significant Agreements - Summary of Changes in Fair Value of Call Option Liability (Details) - One S.r.l $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Beginning balance	$ 2,416
Change in fair value	808
Foreign currency translation gain	(364)
Ending balance	$ 1,244

Significant Agreements - Summ_2

Significant Agreements - Summary of Weighted Average Assumptions Used to Determine Fair Value of Call Option Liability (Details) - One S R L [Member] - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Expected term	4 years	2 years
Expected Volatility	75%	62%
Expected dividend yield	0	0
Risk free interest rate	4.30%	0.70%
Estimated fair value of ownership interest	$ 2,928	$ 6,922
Exercise price of call option	$ 5,879	$ 6,806

Debt - Summary of Non-Convertib

Debt - Summary of Non-Convertible Debt Outstanding (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Total debt obligation	$ 57,712
Non-convertible Debt
Debt Instrument [Line Items]
Total debt obligation	31,860	$ 37,835
Unamortized loan discount and issuance costs	(895)	(754)
Total debt obligation carrying amount	30,965	37,081
Current portion	4,249	1,950
Long-term portion	26,716	35,131
Non-convertible Debt | Italian Economic Development Agency Loan
Debt Instrument [Line Items]
Total debt obligation	303	525
Non-convertible Debt | Intesa Sanpaolo Loan 1
Debt Instrument [Line Items]
Total debt obligation	6,709	8,507
Non-convertible Debt | Intesa Sanpaolo Loan 2
Debt Instrument [Line Items]
Total debt obligation	4,899	5,672
Non-convertible Debt | Horizon 2020 Loan
Debt Instrument [Line Items]
Total debt obligation	388	486
Non-convertible Debt | RIF Shareholders Loan
Debt Instrument [Line Items]
Total debt obligation	14,698	17,015
Non-convertible Debt | UniCredit Loan
Debt Instrument [Line Items]
Total debt obligation	$ 4,863	$ 5,630

Debt - Additional Information (

Debt - Additional Information (Details) $ in Millions			3 Months Ended	9 Months Ended
	Aug. 04, 2022 USD ($) Days Notes	Jan. 19, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 13, 2021 USD ($)
2021 Bridge Financing
Debt Instrument [Line Items]
Principal amount							$ 27
Notes payable							$ 27.1
Loss on change in fair value of the convertible promissory notes				$ (0.2)
Repayment of debt		$ 27.3
2022 Promissory Notes
Debt Instrument [Line Items]
Notes payable			$ 25.9	$ 25.9
Loss on change in fair value of the convertible promissory notes			(0.8)
CMS Bridging DMCC, PureTech Health LLC and SSD2 LLC | 2022 Promissory Notes
Debt Instrument [Line Items]
Number of promissory notes issued | Notes	3
Aggregate principal amount of notes	$ 25
Aggregate cash purchase price	$ 25
SSD2 LLC | 2022 Promissory Notes
Debt Instrument [Line Items]
Interest rate	15%
Maturity date	Dec. 31, 2023
Threshold number of business days following a qualified financing | Days	5
Interest Rate Swap Contract on Intesa Sanpaolo Loan 1
Debt Instrument [Line Items]
Maturity date				Oct. 31, 2029
Net gain loss to change in fair value				$ 0.8	$ 0.1
Interest Rate Swap Contract on Intesa Sanpaolo Loan 1 | Other Assets
Debt Instrument [Line Items]
Fair value of interest rate swap contract			$ 0.7	$ 0.7
Interest Rate Swap Contract on Intesa Sanpaolo Loan 1 | Other Long-Term Liabilities
Debt Instrument [Line Items]
Fair value of interest rate swap contract						$ 0.1

Debt - Summary of Assumptions U

Debt - Summary of Assumptions Used to Determine Fair Value of 2022 Convertible Promissory Notes (Details) - 2022 Convertible Promissory Notes	9 Months Ended
	Sep. 30, 2022
Debt Instrument [Line Items]
Expected Term	1 year 3 months
Weighted average discount rate	26%
Probability of repayment after qualified financing	50%
Probability of holder electing conversion option	50%

Debt - Summary of Future Maturi

Debt - Summary of Future Maturities to Debt Outstanding (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Debt Disclosure [Abstract]
Remaining 2022 obligation	$ 1,063
2023	33,268
2024	4,985
2025	3,627
2026	3,646
More than 5 years	11,123
Total debt obligation carrying amount	$ 57,712

Warrant Liabilities - Summary o

Warrant Liabilities - Summary of Warrants Outstanding (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Class Of Warrant Or Right [Line Items]
Balance	$ 15,821
Assumed upon Business Combination	8,140
Change in fair value	(6,624)
Conversion and exchange upon Business Combination	(16,747)
Balance	590
Series A-4 redeemable convertible preferred stock ("Series A-4")
Class Of Warrant Or Right [Line Items]
Balance	15,821
Change in fair value	926
Conversion and exchange upon Business Combination	(16,747)
Private Placement
Class Of Warrant Or Right [Line Items]
Assumed upon Business Combination	8,140
Change in fair value	(7,550)
Balance	$ 590

Warrant Liabilities - Summary_2

Warrant Liabilities - Summary of Weighted Average Assumptions of Fair Value of Liabilities (Details) - Private Placement - Level 3 - Monte Carlo Simulation value model	Sep. 30, 2022 yr
Expected term
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	4.3
Expected Volatility
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	66
Expected Dividend Yield
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	0
Risk Free Interest Rate
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	4
Price Of Gelesis Common Stock
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	1.08
Exercise Price of Warrants
Class Of Warrant Or Right [Line Items]
Private Placement Warrants	11.50

Warrant Liabilities - Additiona

Warrant Liabilities - Additional Information (Details) - Private Placement	Sep. 30, 2022 $ / shares shares
Class Of Warrant Or Right [Line Items]
Class of Warrant or Right, Outstanding | shares	7,520,000
Class A common stock
Class Of Warrant Or Right [Line Items]
Exercise price of warrants | $ / shares	$ 11.50

Earnout Liability - Additional

Earnout Liability - Additional Information (Details) - shares		9 Months Ended
	Jan. 13, 2022	Sep. 30, 2022
Derivatives, Fair Value [Line Items]
Number of earn out shares unissued and unvested	18,758,241
Earnout Liability
Derivatives, Fair Value [Line Items]
Number of earn out shares unissued and unvested		18,758,241

Earnout Liability - Summary of

Earnout Liability - Summary of Earnout Liability Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Derivatives, Fair Value [Line Items]
Balance
Recognized upon Business Combination	58,871
Changes in fair value	(55,495)
Balance	$ 3,376

Earnout Liability - Summary o_2

Earnout Liability - Summary of Weighted Average Assumptions Used to Determine Fair Value of Earnout Liability (Details) - Level 3 - Monte Carlo Simulation value model - Earnout Liability	Sep. 30, 2022 USD ($) yr
Expected term
Derivatives, Fair Value [Line Items]
Derivative Liability Measurement Input | yr	4.3
Expected Volatility
Derivatives, Fair Value [Line Items]
Derivative Liability Measurement Input	66
Expected Dividend Yield
Derivatives, Fair Value [Line Items]
Derivative Liability Measurement Input	0
Risk Free Interest Rate
Derivatives, Fair Value [Line Items]
Derivative Liability Measurement Input	4
Price Of Gelesis Common Stock
Derivatives, Fair Value [Line Items]
Derivative Liability Measurement Input | $	1.08

Stockholder's Equity (Deficit_2

Stockholder's Equity (Deficit) - Additional Information (Details)			3 Months Ended	9 Months Ended
	Aug. 11, 2022 USD ($) shares	Jan. 13, 2022 shares	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) Days Item $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Jul. 19, 2021 $ / shares shares
Class of Stock [Line Items]
Common shares, shares authorized (in shares)			900,000,000	900,000,000	125,961,571
Common shares, par value (in dollars per share) | $ / shares			$ 0.0001	$ 0.0001	$ 0.0001
Common shares, shares issued (in shares)			72,983,488	72,983,488	6,248,192
Common shares, shares outstanding (in shares)			72,983,488	72,983,488	6,248,192
Preferred stock, shares authorized			250,000,000	250,000,000
Preferred stock, par value | $ / shares			$ 0.0001	$ 0.0001	$ 0.0001
Aggregate common stock value | $			$ 7,000	$ 7,000	$ 1,000
Legal and professional costs | $			1,200,000
Additional paid-in capital | $			295,333,000	295,333,000	$ (64,549,000)
Aggregate purchase price | $				39,000
Common Stock Purchase Agreement
Class of Stock [Line Items]
Additional paid-in capital | $			$ 500,000	$ 500,000
Committed Equity Facility with B. Riley Principal Capital II, LLC | Common Stock Purchase Agreement
Class of Stock [Line Items]
Aggregate common stock value | $	$ 1,200,000
Fair value of common stock issued | $	$ 500,000
Common Stock
Class of Stock [Line Items]
Common shares, shares authorized (in shares)			900,000,000	900,000,000
Common shares, par value (in dollars per share) | $ / shares			$ 0.0001	$ 0.0001
Common shares, shares issued (in shares)			72,983,488	72,983,488
Common shares, shares outstanding (in shares)		72,214,287	72,983,488	72,983,488
Common Stock | Common Stock Purchase Agreement
Class of Stock [Line Items]
Stock Issued during period, Shares, new issues			34,246
Common Stock | Committed Equity Facility with B. Riley Principal Capital II, LLC
Class of Stock [Line Items]
Stock Issued during period, Shares, new issues	14,506,475
Aggregate number of shares of the common stock percentage	19.99%
Common Stock | Committed Equity Facility with B. Riley Principal Capital II, LLC | Common Stock Purchase Agreement
Class of Stock [Line Items]
Volume weighted average price percentage	97%
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Convertible preferred stock exchange ratio		2.59
Convertible preferred stock, terms of conversion				Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable convertible preferred stock converted into Legacy Gelesis common stock and was subsequently split according to the exchange ratio of 2.59. Upon closing of the Business Combination, holders received shares of common stock of the Company on a one-to-one basis.
Common Stock Commitment Shares
Class of Stock [Line Items]
Stock Issued during period, Value, new issues | $			$ 500,000
Common Stock Commitment Shares | Committed Equity Facility with B. Riley Principal Capital II, LLC | Common Stock Purchase Agreement
Class of Stock [Line Items]
Stock Issued during period, Shares, new issues	355,361
Maximum | Common Stock Purchase Agreement
Class of Stock [Line Items]
Aggregate purchase price | $			$ 100,000
Maximum | Common Stock | Committed Equity Facility with B. Riley Principal Capital II, LLC
Class of Stock [Line Items]
Stock Issued during period, Value, new issues | $	$ 50,000,000
Public Warrants
Class of Stock [Line Items]
Number of warrants outstanding			13,800,000	13,800,000
Exercise price of warrants | $ / shares						$ 11.50
Warrants expiration term						5 years
Public Warrants | Common Stock
Class of Stock [Line Items]
Number of warrants outstanding						13,800,000
Public Warrants | Redemption of Warrants When the Price per Class A Ordinary Share Equals or Exceeds $18.00
Class of Stock [Line Items]
Redemption price per public warrant (in dollars per share) | $ / shares				$ 0.01
Redemption period				30 days
Threshold trading days for redemption of public warrants | Days				20
Minimum threshold written notice period for redemption of public warrants | Item				30
Threshold number of business days before sending notice of redemption to warrant holders | Item				3
Public Warrants | Minimum | Redemption of Warrants When the Price per Class A Ordinary Share Equals or Exceeds $18.00
Class of Stock [Line Items]
Class of warrant or right redemption of warrants or rights stock price trigger | $ / shares				$ 18
Roller Warrants
Class of Stock [Line Items]
Number of warrants outstanding			1,353,062	1,353,062		1,353,062
Exercise price of warrants | $ / shares			$ 4.26	$ 4.26		$ 4.26
Warrants exchange ratio		2.59
Warrant conversion terms				Immediately prior to the closing of the Business Combination, Legacy Gelesis redeemable preferred stock warrants were converted into Legacy Gelesis common warrants and were subsequently split according to the exchange ratio of 2.59. Upon closing of the Business Combination, holders received rollover common stock warrants of the Company on a one-to-one basis.
Warrants exercised				176,126
Roller Warrants | Common Stock
Class of Stock [Line Items]
Number of warrants outstanding			1,660,303	1,660,303		1,836,429
Exercise price of warrants | $ / shares			$ 0.02	$ 0.02		$ 0.02
Warrants exchange ratio		2.59
Roller Warrants | Maximum
Class of Stock [Line Items]
Proceeds from warrants exercised | $				$ 100,000

Stockholder's Equity (Deficit_3

Stockholder's Equity (Deficit) - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Common Stock
Common stock issued upon option exercise and RSUs vesting	18,694,129	13,486,708
Sale of Private Placement Warrants (in shares)	24,733,365	1,353,062
Earnout shares	23,482,845
Total common stock reserved for future issuance	66,910,339	65,242,854
Redeemable Convertible Preferred Stock
Common Stock
Conversion of all classes of redeemable convertible preferred stock	0	48,566,655	48,566,655	48,566,655	48,566,655	47,813,946
Series A-4
Common Stock
Sale of Private Placement Warrants (in shares)		1,836,429

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	9 Months Ended	12 Months Ended
	Jan. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total fair value of options vested		$ 3.9
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost		$ 10.7	$ 6.7
Weighted-average period of unrecognized compensation cost expected to be recognized		2 years 10 months 24 days	10 months 24 days
2021 Stock Option Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized to issue on common stock	9,583,570
Remaining shares available for issuance		3,321,470
Increase in percentage, number of shares of stock issued and outstanding	4%
Expiration period of awards granted		10 years
Weighted-average grant date fair value of stock options granted		$ 2.17
Unrecognized compensation cost		$ 10.1	$ 8.7
Weighted-average period of unrecognized compensation cost expected to be recognized		2 years 3 months 18 days	2 years 2 months 12 days
2021 Stock Option Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		3 years
2021 Stock Option Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - Employees and Non Employees - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 4,574	$ 1,086	$ 26,539	$ 4,180
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	1,058	243	9,131	1,304
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 3,516	$ 843	$ 17,408	$ 2,876

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding	12,674,486
Number of Options, Granted	2,658,185
Number of Options, Exercised	(162,064)
Number of Options, Forfeited - unvested	(548,653)
Number of Options, Forfeited - vested	(63,718)
Number of Options, Expired	(456,534)
Number of Options, Outstanding	14,101,702	12,674,486
Number of Options, Exercisable	10,218,998
Number of Options, Vested and expected to vest	14,101,702
Weighted Average Exercise Price per Share
Weighted- Average Exercise Price per Share, Outstanding	$ 4.01
Weighted- Average Exercise Price per Share, Granted	3.35
Weighted- Average Exercise Price per Share, Exercised	0.68
Weighted- Average Exercise Price per Share, Forfeited - unvested	5.23
Weighted- Average Exercise Price per Share, Forfeited - vested	4.31
Weighted- Average Exercise Price per Share, Expired	1.23
Weighted- Average Exercise Price per Share, Outstanding	3.96	$ 4.01
Weighted- Average Exercise Price per Share, Exercisable	3.89
Weighted- Average Exercise Price per Share, Vested and expected to vest	$ 3.96
Weighted Average Remaining Contractual Term (Years)
Weighted- Average Remaining Contractual Term (Years), Outstanding	6 years 3 months 21 days	6 years 2 months 1 day
Weighted- Average Remaining Contractual Term (Years), Exercisable	5 years 3 months 18 days
Weighted- Average Remaining Contractual Term (Years), Vested and expected to vest	6 years 3 months 21 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding	$ 502	$ 54,449
Aggregate Intrinsic Value, Exercisable	502
Aggregate Intrinsic Value, Vested and expected to vest	$ 502
Previously Reported
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding	4,889,820
Number of Options, Outstanding		4,889,820
Weighted Average Exercise Price per Share
Weighted- Average Exercise Price per Share, Outstanding	$ 10.39
Weighted- Average Exercise Price per Share, Outstanding		$ 10.39
Weighted Average Remaining Contractual Term (Years)
Weighted- Average Remaining Contractual Term (Years), Outstanding		6 years 2 months 1 day
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Outstanding		$ 54,449
Retroactive Application of Reverse Recapitalization
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options, Outstanding	7,784,666
Number of Options, Outstanding		7,784,666
Weighted Average Exercise Price per Share
Weighted- Average Exercise Price per Share, Outstanding	$ (6.38)
Weighted- Average Exercise Price per Share, Outstanding		$ (6.38)

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Grant Date Fair Value of Options Issued Using Black-Scholes Weighted Average Assumptions (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Market price of common stock	$ 3.35
Expected volatility	72.40%
Expected term (in years)	6 years 1 month 6 days
Risk-free interest rate	1.70%
Expected dividend yield	0%

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs, Outstanding and Unvested | shares	812,222
Number of RSUs, Granted | shares	4,555,197
Number of RSUs, Vested | shares	(41,404)
Number of RSUs, Forfeited | shares	(640,849)
Number of RSUs, Outstanding and Unvested | shares	4,685,166
Weighted- Average Grant Date Fair Value, Outstanding and Unvested | $ / shares	$ 8.26
Weighted- Average Grant Date Fair Value, Granted | $ / shares	3.46
Weighted- Average Grant Date Fair Value, Vested | $ / shares	6.77
Weighted- Average Grant Date Fair Value, Forfeited | $ / shares	3.35
Weighted- Average Grant Date Fair Value, Outstanding and Unvested | $ / shares	$ 4.28
Previously Reported
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs, Outstanding and Unvested | shares	313,354
Weighted- Average Grant Date Fair Value, Outstanding and Unvested | $ / shares	$ 21.41
Retroactive Application of Reverse Recapitalization
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs, Outstanding and Unvested | shares	498,868
Weighted- Average Grant Date Fair Value, Outstanding and Unvested | $ / shares	$ (13.15)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Examination [Line Items]
Provision for income taxes	$ 0	$ 0	$ 0	$ 17,000
U.S statutory rate			21%	21%
Maximum
Income Tax Examination [Line Items]
Provision for income taxes				$ 100,000

Earnings (Loss) Per Share - Sum

Earnings (Loss) Per Share - Summary of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net loss	$ (14,149)	$ (12,513)	$ (5,703)	$ (30,730)	$ (24,739)	$ (18,586)	$ (32,365)	$ (74,055)
Accretion of redeemable convertible preferred stock to redemption value				(23,111)			(37,934)	(139,237)
Accretion of noncontrolling interest put option to redemption value	(80)			(95)			(253)	(285)
Net loss attributable to common stockholders	$ (14,229)			$ (53,936)			$ (70,552)	$ (213,577)
Denominator:
Weighted average common shares outstanding, basic and diluted	72,772,627			5,615,192			69,349,679	5,592,931
Net loss per share attributable to common stockholders - basic and diluted	$ (0.20)			$ (9.61)			$ (1.02)	$ (38.19)

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Anti-dilutive Securities Excluded from Computation of Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share	43,427,494	65,311,620
Warrants on Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share		1,836,429
Options and RSU to Acquire Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share	18,694,129	13,555,474
Warrants on Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share	24,733,365	1,353,062
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of net loss per share		48,566,655

Earnings (Loss) per Share (Addi

Earnings (Loss) per Share (Additional Information) (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2022 shares	Sep. 30, 2022 shares	Jan. 13, 2022
Earnings Per Share [Abstract]
Potentially dilutive common share equivalents	23,482,845	23,482,845
Common stock exchange ratio			2.59

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Details) $ in Thousands, € in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Jun. 30, 2019 USD ($)	Dec. 31, 2009	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 EUR (€)	Dec. 31, 2021 USD ($)
Loss Contingencies [Line Items]
Operating lease commencement	2019-06
Operating lease expiration	2025-08
Total lease payments			$ 1,802		$ 1,802
Operating lease right-of-use assets			1,627		1,627			$ 2,016
Short-term lease liabilities			578		578			541
Long-term lease liabilities			1,095		1,095			1,519
Operating lease expense			$ 200	$ 200	$ 500	$ 500
Operating lease remaining lease terms			2 years 10 months 24 days		2 years 10 months 24 days		2 years 10 months 24 days
Operating lease weighted average discount rate, percent			5.30%		5.30%		5.30%
Other long-term liabilities			$ 3,912		$ 3,912			5,588
Office space located in Boston
Loss Contingencies [Line Items]
Total lease payments	$ 3,200
Research and Development Tax credits
Loss Contingencies [Line Items]
Other long-term liabilities			2,600		$ 2,600			$ 3,000
PureTech | Royalty and Sublicense Income Agreement
Loss Contingencies [Line Items]
Royalty payment required percentage		2%
One S.r.l | Amended And Restated Master Agreement
Loss Contingencies [Line Items]
Percentage of royalty					2%
Payments to be made upon the achievement of certain milestones			$ 17,100		$ 17,100		€ 17.5

Commitment and Contingencies _2

Commitment and Contingencies - Schedule of Future Maturities of the Lease Liability Under the Company's Noncancelable Operating Leases (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remaining 2022 maturities	$ 163
2023	649
2024	567
2025	381
2026	29
More than 5 Years	13
Total undiscounted lease maturities	1,802
Imputed interest	(129)
Total lease liability	$ 1,673

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 19, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jul. 25, 2022	Dec. 31, 2021	Dec. 13, 2021
Related Party Transaction [Line Items]
Accounts payable, due to related party		$ 458		$ 458			$ 147
Loss of change in fair value of the instrument		(852)		(1,008)
PureTech
Related Party Transaction [Line Items]
Principal amount						$ 15,000		$ 15,000
Repayment of debt	$ 15,200
PureTech | Management Services Expenses
Related Party Transaction [Line Items]
Research and development, including related party expenses		100	$ 100	400	$ 200
Accounts payable, due to related party		300		300			100
Notes payable		15,600		15,600			15,100
Loss of change in fair value of the instrument		600		100
PureTech | Royalty Expense
Related Party Transaction [Line Items]
Research and development, including related party expenses		100	$ 100	500	$ 300
SSD2
Related Party Transaction [Line Items]
Principal amount						$ 5,000		$ 12,000
Loss of change in fair value of the instrument				100
Repayment of debt	$ 12,100
SSD2 | Management Services Expenses
Related Party Transaction [Line Items]
Notes payable		5,200		$ 5,200			$ 12,100
Loss of change in fair value of the instrument		$ 200

Related Party Transactions - _2

Related Party Transactions - Additional Information - One S.r.l (Details) € in Millions, $ in Millions	3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2022 EUR (€)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)
Founder of One | Consulting Agreement | Maximum
Related Party Transaction [Line Items]
Research and development, including related party expenses	$ 0.1	$ 0.1	$ 0.2		$ 0.2
Outstanding accrued expenses and remaining undiscounted payments, related parties	0.1		0.1			$ 0.1
One S.r.l
Related Party Transaction [Line Items]
Outstanding accrued expenses and remaining undiscounted payments, related parties	0.1		0.1
Payments related to acquisition			2.4	€ 2.5		5.7	€ 5
Notes payable	0.2		0.2
One S.r.l | Maximum
Related Party Transaction [Line Items]
Outstanding accrued expenses and remaining undiscounted payments, related parties						$ 0.1
One S.r.l | Consulting Agreement
Related Party Transaction [Line Items]
Payments related to acquisition			2.9
One S.r.l | Royalty Expense
Related Party Transaction [Line Items]
Payments related to acquisition	$ 0.1	$ 0.1	$ 0.4		$ 0.2
One S.r.l | Equity Interest
Related Party Transaction [Line Items]
Equity interest acquired (as a percent)	10%		10%

Related Party Transactions - _3

Related Party Transactions - Additional Information - RIF (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Aug. 31, 2020	Sep. 30, 2022
Equity investment that can be called beginning in December 2023 and ending in December 2026
Related Party Transaction [Line Items]
Annual interest rate in connection with transaction		15%
Put by RIF starting in January 2027 and ending in December 2027
Related Party Transaction [Line Items]
Annual interest rate in connection with transaction		3.175%
RIF Transaction
Related Party Transaction [Line Items]
Proceeds from sale of equity investment	$ 12.3
Equity interest held by related party		20%
Loan from related party		$ 18.4
Fixed interest rate on loan		6.35%

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event	Nov. 02, 2022 $ / shares
Subsequent Event [Line Items]
Minimum share price requirement trading days period	30 days
Minimum
Subsequent Event [Line Items]
Average closing price of common stock	$ 1
Maximum
Subsequent Event [Line Items]
Date of stock price return to level over $1.00	May 02, 2023