Sec Form 4 Filing - COLUMN GROUP L P @ CONSTELLATION PHARMACEUTICALS INC - 2020-03-19

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 COLUMN GROUP L P 2. Issuer Name and Ticker or Trading Symbol CONSTELLATION PHARMACEUTICALS INC [ CNST] 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) 1700 OWENS STREET, SUITE 500 3. Date of Earliest Transaction (MM/DD/YY) 03/19/2020 (Street) SAN FRANCISCO, CA94158 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 03/19/2020 P 36,135 ( 1 ) A $ 22.38 6,045,837 D ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) Common Stock 03/20/2020 P 5,539 ( 7 ) A $ 23.15 6,051,376 ( 8 ) D ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) Common Stock 159,155 I ( 9 ) See Footnote

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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other COLUMN GROUP L P 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X COLUMN GROUP GP, LP 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X PONOI CAPITAL, LP 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X Ponoi Management, LLC 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X General Partner Ponoi Capital II, LP 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X Ponoi II Management, LLC 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X General Partner Kutzkey Tim 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X Managing Partner GOEDDEL DAVID V 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X Managing Partner Svennilson Peter 1700 OWENS STREET SUITE 500 SAN FRANCISCO, CA94158 X Managing Partner Signatures /s/ Jennifer J. Carlson, Attorney-in-Fact 03/23/2020 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Consists of 16,970 shares of common stock held directly by The Column Group III, LP ("TCG III LP") and 19,165 shares of common stock held directly by The Column Group III-A, LP ("TCG III-A LP"). ( 2 )The securities are directly held by The Column Group, LP, and indirectly held by The Column Group GP, LP, the general partner of The Column Group, LP. The managing partners of The Column Group GP, LP are David Goeddel and Peter Svennilson. The managing partners of The Column Group GP, LP may be deemed to have voting and investment power with respect to such shares. Each individual managing partner disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest in such shares. ( 3 )The securities are directly held by Ponoi Capital, LP, and indirectly held by Ponoi Management, LLC, the general partner of Ponoi Capital, LP. The managing partners of Ponoi Management, LLC are David Goeddel, Peter Svennilson, and Tim Kutzkey. The managing partners of Ponoi Management, LLC may be deemed to have voting and investment power with respect to such shares. Each individual managing partner disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest in such shares. ( 4 )The securities are directly held by Ponoi Capital II, LP, and indirectly held by Ponoi II Management, LLC, the general partner of Ponoi Capital II, LP. The managing partners of Ponoi II Management, LLC are David Goeddel, Peter Svennilson, and Tim Kutzkey. The managing partners of Ponoi II Management, LLC may be deemed to have voting and investment power with respect to such shares. Each individual managing partner disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest in such shares. ( 5 )The securities are directly held by TCG III, and indirectly held by The Column Group III GP, LP ("TCG III GP"), the general partner of TCG III. The managing partners of TCG III GP are David Goeddel, Peter Svennilson and Tim Kutzkey. The managing partners of TCG III GP may be deemed to have voting and investment power with respect to such shares. Each individual managing partner disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest in such shares. ( 6 )The securities are directly held by TCG III-A LP, and indirectly held by TCG III GP, the general partner of TCG III-A LP. The managing partners of TCG III GP are David Goeddel, Peter Svennilson and Tim Kutzkey. The managing partners of TCG III GP may be deemed to have voting and investment power with respect to such shares. Each individual managing partner disclaims beneficial ownership of these shares, except to the extent of his pecuniary interest in such shares. ( 7 )Consists of 2,601 shares of common stock held directly by TCG III LP and 2,938 shares of common stock held directly by TCG III-A LP. ( 8 )Consists of 2,554,850 shares of common stock held directly by The Column Group, LP, 1,880,623 shares of common stock held directly by Ponoi Capital, LP, 1,574,229 shares of common stock held directly by Ponoi Capital II, LP, 19,571 shares of common stock held directly by TCG III LP and 22,103 shares of common stock held directly by TCG III-A LP. ( 9 )The securities are held directly by The David V. and Alena Z. Goeddel 2004 Trust.

Remarks: Due to SEC restrictions on the number of reporting owners, this is Form 1 of 2.

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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