Sec Form 4 Filing - Bolzon Bradley J PhD @ Monte Rosa Therapeutics, Inc. - 2021-02-24

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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Bolzon Bradley J PhD 2. Issuer Name and Ticker or Trading Symbol Monte Rosa Therapeutics, Inc. [ GLUE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) MONTE ROSA THERAPEUTICS, INC., 645 SUMMER STREET, SUITE 102 3. Date of Earliest Transaction (MM/DD/YY) 02/24/2021 (Street) BOSTON, MA02210 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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

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 ) 02/24/2021 A( 2 ) 1,500,000 ( 1 ) ( 1 ) Common Stock 424,869 $ 2 3,000,000 I By Versant Capital VI, L.P. ( 3 ) Series B convertible preferred stock ( 1 ) 02/24/2021 A( 2 ) 2,075,000 ( 1 ) ( 1 ) Common Stock 587,735 $ 2 4,150,000 I By Versant Vantage I, L.P. ( 4 ) Series C convertible preferred stock ( 1 ) 03/11/2021 A( 2 ) 2,699,328 ( 1 ) ( 1 ) Common Stock 764,573 $ 2.9637 2,699,328 I By Versant Vantage I, L.P. ( 4 ) Stock Option (Right to Buy) $ 19 06/23/2021 A 47,132 ( 5 ) 06/22/2031 Common Stock 47,132 $ 0 47,132 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Bolzon Bradley J PhD MONTE ROSA THERAPEUTICS, INC. 645 SUMMER STREET, SUITE 102 BOSTON, MA02210 X X Signatures /s/ Ajim Tamboli, Attorney-in-Fact 06/25/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") is convertible into shares of the Issuer's Common Stock on a 3.5305-for-one basis. Upon the closing of the Issuer's initial public offering, all shares of Preferred Stock will convert into the number of shares of Common Stock of the Issuer shown in column 7. The Preferred Stock has no expiration date. ( 2 )This transaction occurred prior to the Issuer's initial public offering, and is being reported on Form 4 solely for purposes of compliance with Rule 16a-2(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"). The securities covered by such transaction were previously included on the Reporting Person's Form 3. ( 3 )Shares held by Versant Venture Capital VI, L.P. ("Versant VI"). Versant Ventures VI GP, L.P. ("Versant Ventures VI GP") is the general partner of Versant VI, and Versant Ventures VI GP-GP, LLC ("Versant Ventures VI GP-GP") is the general partner of Versant Ventures VI GP. The Reporting Person is a managing member of Versant Ventures VI GP-GP and may be deemed to share voting and dispositive power over the shares held by Versant VI. The Reporting Person disclaims beneficial ownership of such securities, except to the extent of his pecuniary interest therein, if any. ( 4 )Shares held by Versant Vantage I, L.P. ("Versant Vantage I"). Versant Vantage I GP, ("Versant Vantage I GP") is the general partner of Versant Vantage I, and Versant Vantage I GP-GP, LLC ("Versant Vantage I GP-GP") is the general partner of Versant Vantage I GP. The Reporting Person is a managing member of Versant Vantage I GP-GP, and may be deemed to share voting and dispositive power over the shares held by Versant Vantage I. The Reporting Person disclaims beneficial ownership of such securities, except to the extent of his pecuniary interest therein, if any. ( 5 )This option shall vest in 36 substantially equal monthly installments, with the first installment vesting on June 28, 2021.

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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.