UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

Amendment No. 2

x   ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2021

¨   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

GELESIS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 456-4718

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ¨ No x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act. Yes ¨ No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes x No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definition of “large accelerated filer,” “accelerated filer, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act by the registered public accounting firm that prepared or issued its audit report. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No x

As of June 30, 2021, the last business day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the shares of Class A common stock outstanding, other than shares held by persons who may be deemed affiliates of the registrant, computed by reference to the closing sales price for the shares of Class A common stock on June 30, 2021, as reported on the New York Stock Exchange, was approximately $270,194,493 (based on the closing sales price of the shares of Class A common stock on June 30, 2021 of $9.79). The shares of Class A common stock automatically converted into common stock in connection with the Business Combination, as defined herein.

As of March 31, 2022, 72,390,413 shares of common stock, par value $0.0001 were issued and outstanding.

Explanatory Note

Gelesis Holdings, Inc. (the “Company”) is filing this Amendment No. 2 on Form 10-K/A (this “Amendment No. 2”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2021 that was filed with the Securities and Exchange Commission (the “SEC”) on April 1, 2022 (the “Original Report”), as amended by Amendment No. 1 that was filed with the SEC on May 2, 2022 (the “Amendment No. 1”), for the purpose of filing revised versions of Exhibits 31.1 and 31.2 filed with the Original Report and Exhibits 31.3 and 31.4 filed with the Amendment No. 1.

The Company is filing revised exhibits solely in order to include in the certifications set forth in Exhibits 31.1, 31.2, 31.3 and 31.4 the language added to the introductory portion of paragraph 4 and the language of revised paragraph 4(b), which language was inadvertently omitted from the certifications when originally filed. Except as explicitly set forth in the Amendment No. 1, the Amendment No. 2 does not reflect events occurring after the date of the filing of the Original Report or modify or update any of the other disclosures contained therein in any way. Accordingly, the Amendment No. 2 should be read in conjunction with the Original Report, as amended by the Amendment No. 1. The Amendment No. 2 consists solely of the preceding cover page, this explanatory note, an exhibit index, the signature page and paragraphs 1, 2, 4 and 5 of each of the revised certifications filed as exhibits to the Amendment No. 2.

Item 15. Exhibits, Financial Statement Schedules

(b) Exhibits:

The following is a list of all exhibits filed or furnished as part of this report.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: June 8, 2022

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.