Ownership Submission
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 OF SECURITIES

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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(Print or Type Responses)
1. Name and Address of Reporting Person *
BAY CITY CAPITAL LLC
  2. Issuer Name and Ticker or Trading Symbol
Epizyme, Inc. [EPZM]
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)
750 BATTERY STREET, SUITE 400
3. Date of Earliest Transaction (Month/Day/Year)
06/05/2013
(Street)

SAN FRANCISCO, CA 94111
4. If Amendment, Date Original Filed(Month/Day/Year)
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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 06/05/2013   C   3,426,762 A (1) 3,426,762 I See Footnotes (2) (3)
Common Stock 06/05/2013   C   65,301 A (1) 3,492,063 I See Footnotes (2) (4)
Common Stock 06/05/2013   P   163,549 A $ 15 3,655,612 I See Footnotes (2) (3)
Common Stock 06/05/2013   P   3,117 A $ 15 3,658,729 I See Footnotes (2) (4)

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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 (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 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
(Month/Day/Year)
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 Preferred Stock (1) 06/05/2013   C     10,280,288   (1)   (5) Common Stock 3,426,762 $ 0 0 I See Footnotes (2) (3)
Series B Preferred Stock (1) 06/05/2013   C     195,904   (1)   (5) Common Stock 65,301 $ 0 0 I See Footnotes (2) (4)
Stock Option (right to buy) $ 25.73 06/05/2013   A   17,666     (6) 06/04/2023 Common Stock 17,666 $ 0 17,666 I See Footnote (7)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BAY CITY CAPITAL LLC
750 BATTERY STREET
SUITE 400
SAN FRANCISCO, CA 94111
    X    
Bay City Capital Fund V, L.P.
750 BATTERY STREET
SUITE 400
SAN FRANCISCO, CA 94111
    X    
Bay City Capital Fund V Co-Investment Fund, L.P.
750 BATTERY STREET
SUITE 400
SAN FRANCISCO, CA 94111
    X    
Bay City Capital Management V LLC
750 BATTERY STREET
SUITE 400
SAN FRANCISCO, CA 94111
    X    

Signatures

 /s/ Carl Goldfischer   06/07/2013
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) Each share of Series B Preferred Stock was automatically converted into 1/3rd of a share of Common Stock upon the closing of the Issuer's initial public offering without payment of consideration.
(2) Bay City Capital LLC, a Delaware limited liability company ("BCC"), Bay City Capital Management V LLC, a Delaware limited liability company ("Management V"), Bay City Capital Fund V, L.P., a Delaware limited partnership ("Fund V"), and Bay City Capital Fund V Co-Investment Fund, L.P., a Delaware limited partnership ("Co-Investment V"), are deemed to be a "group" for the purpose of Section 13(d) under the Securities Exchange Act of 1934. Management V is the general partner of Fund V and Co-Investment V and has sole voting and dispositive power with respect to the securities held by Fund V and Co-Investment V. BCC, the manager of Management V, is also an advisor to Fund V and Co-Investment V and has sole voting and dispositive power with respect to the securities held by Fund V and Co-Investment V.
(3) Represent securities held by Fund V, including indirect interests of BCC and Management V. BCC and Management V each disclaims beneficial ownership with respect to these securities, except to the extent of their pecuniary interest therein.
(4) Represent securities held by Co-Investment V, including indirect interests of BCC and Management V. BCC and Management V each disclaims beneficial ownership with respect to these securities, except to the extent of their pecuniary interest therein.
(5) Not applicable.
(6) Vests in full upon the earlier of (i) the expiration of the Dr. Goldfischer's initial term of office as a director of the Issuer, scheduled to occur on the 2015 annual meeting of the Issuer's stockholders and (ii) June 30, 2015. In the event of a change in control of the Issuer, the vesting schedule of the option will accelerate in full.
(7) BCC and Management V have an arrangement with Dr. Goldfischer, the beneficial owner of the option, that provides such entities with a pecuniary interest in the option issued by the Issuer to Dr. Goldfischer. BCC and Management V each disclaims beneficial ownership in such option, except to the extent of their pecuniary interest therein.
 
Remarks:
Signed by Carl Goldfischer, Managing Director BCC for itself, for and on behalf of Management V in its capacity as manager thereof, and for and on behalf of Fund V and Co-Investment V in its capacity as manager of Management V, the general partner of Fund V and Co-Investment V.

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