FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF 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 *   Horvitz H Robert 2. Date of Event Requiring Statement (Month/Day/Year) 05/30/2013 3. Issuer Name and Ticker or Trading Symbol Epizyme, Inc. [EPZM] (Last) (First) (Middle) 77 MASSACHUSETTS AVE. DEPT. BIOLOGY, ROOM 68-425, MIT 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) CAMBRIDGE, MA 02139 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 Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 161,876 (1) D   Common Stock 24,660 (1) I By H. Robert Horvitz 1997 Irrevocable Trust

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	  (2)	09/04/2018	Common Stock	19,039 (1)	$ 0.33 (1)	D	Â
Stock Option (right to buy)	  (2)	04/23/2019	Common Stock	42,074 (1)	$ 0.33 (1)	D	Â
Series A Preferred Stock	  (3)	  (3)	Common Stock	16,666	$ (3)	D	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Horvitz H Robert 77 MASSACHUSETTS AVE. DEPT. BIOLOGY ROOM 68-425, MIT CAMBRIDGE, MA 02139	Â	  X	Â	Â

Signatures

/s/ H. Robert Horvitz		05/30/2013
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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)	Reflects a one-for-three reverse stock split effected on May 13, 2013.
(2)	This option is fully vested.
(3)	Each share of Series A Preferred Stock is convertible into 1/3rd of a share of Common Stock without payment of further consideration and will automatically convert into 1/3rd of a share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date.

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