UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) OR 12(g) OF THE

SECURITIES EXCHANGE ACT OF 1934

Collegium Pharmaceutical, Inc.

(Exact name of registrant as specified in its charter)

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

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box. x

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box. o

Securities Act registration statement file number to which this form relates: File No. 333-203208

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

INFORMATION REQUIRED IN REGISTRATION STATEMENT

Item 1.  Description of Registrant’s Securities to be Registered

A description of the common stock, par value $0.001 per share, of Collegium Pharmaceutical, Inc., a Virginia corporation (the “Registrant”), is set forth under the heading “Description of Capital Stock” contained in the Registrant’s Registration Statement on Form S-1 (File No. 333-203208), originally filed with the Securities and Exchange Commission on April 2, 2015, as subsequently amended, and is hereby incorporated herein by reference. The description of the common stock included in any form of prospectus subsequently filed by the Registrant pursuant to Section 424(b) of the Securities Act of 1933, as amended, shall also be deemed to be incorporated herein by reference.

Item 2.  Exhibits

Pursuant to the Instructions as to Exhibits with respect to Form 8-A, no exhibits are required to be filed because no other securities of the Registrant are registered on The NASDAQ Stock Market LLC and the securities registered hereby are not being registered pursuant to Section 12(g) of the Exchange Act.

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SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized.

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