Sec Form 4 Filing - Longitude Capital Partners, LLC @ COLLEGIUM PHARMACEUTICAL, INC - 2015-05-12

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Longitude Capital Partners, LLC 2. Issuer Name and Ticker or Trading Symbol COLLEGIUM PHARMACEUTICAL, INC [ COLL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 800 EL CAMINO REAL SUITE 220 3. Date of Earliest Transaction (MM/DD/YY) 05/12/2015 (Street) MENLO PARK, CA94024 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/12/2015 C 3,060,502 A 3,060,502 ( 2 ) I By Longitude Venture Partners, L.P. ( 3 ) Common Stock 05/12/2015 P 196,070 A $ 12 3,256,572 I By Longitude Venture Partners, L.P. ( 3 ) Common Stock 05/12/2015 C 61,340 A 61,340 ( 2 ) I By Longitude Capital Associates, L.P. ( 3 ) Common Stock 05/12/2015 P 3,930 A $ 12 65,270 I By Longitude Capital Associates, L.P. ( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series B Convertible Preferred Stock ( 1 ) 05/12/2015 C 12,837,935 ( 1 ) ( 1 ) ( 1 ) Common Stock 1,860,570 ( 2 ) $ 0 0 I By Longitude Venture Partners, L.P. ( 3 ) Series B Convertible Preferred Stock ( 1 ) 05/12/2015 C 257,303 ( 1 ) ( 1 ) ( 1 ) Common Stock 37,290 ( 2 ) $ 0 0 I By Longitude Capital Associates, L.P. ( 3 ) Series C Convertible Preferred Stock ( 1 ) 05/12/2015 C 3,160,905 ( 1 ) ( 1 ) ( 1 ) Common Stock 458,102 ( 2 ) $ 0 0 I By Longitude Venture Partners, L.P. ( 3 ) Series C Convertible Preferred Stock ( 1 ) 05/12/2015 C 63,356 ( 1 ) ( 1 ) ( 1 ) Common Stock 9,182 ( 2 ) $ 0 0 I By Longitude Capital Associates, L.P. ( 3 ) Series D Convertible Preferred Stock ( 1 ) 05/12/2015 C 5,045,381 ( 1 ) ( 1 ) ( 1 ) Common Stock 741,830 ( 2 ) $ 0 0 I By Longitude Venture Partners, L.P. ( 3 ) Series D Convertible Preferred Stock ( 1 ) 05/12/2015 C 101,128 ( 1 ) ( 1 ) ( 1 ) Common Stock 14,868 ( 2 ) $ 0 0 I By Longitude Capital Associates, L.P. ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Longitude Capital Partners, LLC 800 EL CAMINO REAL SUITE 220 MENLO PARK, CA94024 X Longitude Capital Associates, L.P. 800 EL CAMINO REAL SUITE 220 MENLO PARK, CA94024 X Longitude Venture Partners L.P. 800 EL CAMINO REAL SUITE 220 MENLO PARK, CA94024 X Tammenoms Bakker Juliet 800 EL CAMINO REAL SUITE 220 MENLO PARK, CA94024 X ENRIGHT PATRICK G 800 EL CAMINO REAL SUITE 220 MENLO PARK, CA94024 X Signatures /s/ Longitude Capital Partners, LLC by Patrick G. Enright Managing Member 05/14/2015 Signature of Reporting Person Date /s/ Longitude Capital Associates, L.P. by Longitude Capital Partners, LLC, General Partner, by Patrick G. Enright, Managing Member 05/14/2015 Signature of Reporting Person Date /s/ Longitude Venture Partners, L.P. by Longitude Capital Partners, LLC, General Partner, by Patrick G. Enright, Managing Member 05/14/2015 Signature of Reporting Person Date /s/ Juliet Tammenoms Bakker, Managing Member 05/14/2015 Signature of Reporting Person Date /s/ Patrick G. Enright, Managing Member 05/14/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )All series of convertible preferred stock automatically converted into Collegium Pharmaceutical, Inc. common stock on a 1-for-6.9 basis immediately prior to the closing of the initial public offering and had no expiration date. ( 2 )Reflects the conversion of preferred stock into Collegium Pharmaceutical, Inc. common stock on a 1-for-6.9 basis which became effective on May 12, 2015, and includes 10,616 shares issued on May 12, 2015 to LVP, and 212 shares issued on May 12, 2015 to LCA, upon conversion of the Series D Convertible Preferred Stock in payment of accrued dividends thereon. ( 3 )This report is filed jointly by Longitude Capital Partners, LLC ("LCP"), Longitude Venture Partners, L.P. ("LVP"), Longitude Capital Associates, L.P. ("LCA"), Patrick G. Enright ("Enright") and Juliet Tammenoms Bakker ("Bakker"), all of whom share beneficial ownership of more than 10% of the capital stock of the Issuer. LCP, as general partner of each of LVP and LCA, has the power to vote and dispose of securities held by each of them and may be deemed to have beneficial ownership of the shares owned by LVP and LCA. Enright and Bakker are each managing members of LCP and in their capacity as such, may be deemed to exercise shared voting and investment power over the shares held by the reporting persons. Each of LCP, Enright and Bakker disclaims beneficial ownership of the securities of the Issuer held by LVP and LCA except to the extent of their respective pecuniary interest therein.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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