SEC Form S-8 filed by Collegium Pharmaceutical Inc.

As filed with the Securities and Exchange Commission on June 1, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM S-8

REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

Collegium Pharmaceutical, Inc.

(Exact name of registrant as specified in its charter)

2015 EMPLOYEE STOCK PURCHASE PLAN

(Full title of the plan)

Colleen Tupper

Executive Vice President and Chief Financial Officer

100 Technology Center Drive
Stoughton, MA 02072

(781) 713-3699

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

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 the definitions 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 7(a)(2)(B) of the Securities Act. ¨

EXPLANATORY NOTE

This Registration Statement on Form S-8 is being filed for the purpose of registering an additional 317,076 shares of Common Stock of the Registrant that were added to the shares authorized for issuance under the Collegium Pharmaceutical, Inc. 2015 Employee Stock Purchase Plan (the “ESPP”) for which a Registration Statement on Form S-8 relating to the same employee benefit plans is effective. Pursuant to General Instruction E to Form S-8, the contents of the Registration Statements on Form S-8 (File Nos. 333-207744, 333-218767, 333-225498, 333-233092, 333-245649, 333-258752, 333-266778, 333-273874, 333-281571 and 333-285593) filed with the Securities and Exchange Commission (the “Commission”) on November 2, 2015, June 15, 2017, June 7, 2018, August 7, 2019, August 13, 2020, August 12, 2021, August 11, 2022, August 10, 2023, August 15, 2024 and March 6, 2025, as amended, are incorporated herein by reference except to the extent supplemented, amended or superseded by the information set forth herein. Only those items of Form S-8 containing new information not contained in the earlier registration statements are presented herein.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents of the Registrant filed with the Commission are incorporated by reference in this Registration Statement as of their respective dates:

All documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference into this Registration Statement and to be a part hereof from the date of filing of such documents; provided, however, that documents or information deemed to have been furnished and not filed in accordance with Commission rules shall not be deemed incorporated by reference into this Registration Statement. Any statement contained herein or in a document, all or a portion of which is incorporated or deemed to be incorporated by reference herein, shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or amended, to constitute a part of this Registration Statement.

Item 8. Exhibits.

EXHIBIT INDEX

*       Filed herewith.

(1) Previously filed as an exhibit to the Registrant’s Quarterly Report on Form 10-Q, filed with the Commission on August 5, 2020.

(2) Previously filed as an exhibit to the Registrant’s Current Report on Form 8-K filed with the Commission on December 4, 2017.

(3) Previously filed as an exhibit to the Registrant’s Registration Statement on Form S-8 (File No. 333-207744) filed with the Commission on November 2, 2015.

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Town of Stoughton, Commonwealth of Massachusetts, on this 1^st day of June, 2026.

POWER OF ATTORNEY

We, the undersigned officers and directors of Collegium Pharmaceutical, Inc., hereby severally constitute and appoint Vikram Karnani, Colleen Tupper and David Dieter, and each of them singly, our true and lawful attorneys with full power to them, and each of them singly, to sign for us and in our names in the capacities indicated below, the Registration Statement filed herewith and any and all subsequent amendments to said Registration Statement, and generally to do all such things in our names and on our behalf in our capacities as officers and directors to enable Collegium Pharmaceutical, Inc. to comply with the provisions of the Securities Act and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming our signatures as they may be signed by our said attorneys, or any of them, to said Registration Statement and any and all amendments thereto.

Pursuant to the requirements of the Securities Act, this Registration Statement on Form S-8 has been signed by the following persons in the capacities indicated on June 1, 2026.