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 *   ALNYLAM PHARMACEUTICALS, INC. 2. Date of Event Requiring Statement (Month/Day/Year) 10/04/2012 3. Issuer Name and Ticker or Trading Symbol Regulus Therapeutics Inc. [RGLS] (Last) (First) (Middle) 300 THIRD STREET, 3RD FLOOR 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 02142 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)

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
Series A Preferred Stock	  (1)	  (1)	Common Stock	6,150,500	$ (1)	D (2)	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ALNYLAM PHARMACEUTICALS, INC. 300 THIRD STREET, 3RD FLOOR CAMBRIDGE, MA 02142	Â	  X	Â	Â

Signatures

/s/ Barry E. Greene, President and COO of the Reporting Person		10/04/2012
**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)	The Series A Preferred Stock has no expiration date and is convertible at any time at the option of the holder and will convert upon the closing of the Issuer's initial public offering at a conversion ratio of 1 share of Common Stock for every 2 shares of Series A Preferred Stock, for no additional consideration.
(2)	Barry E. Greene and John M. Maraganore, Ph.D., are each officers and, in Dr. Maraganore's case, a director, of the Reporting Person and therefore may be deemed to have control and indirect beneficial ownership of shares held by the Reporting Person. Mr. Greene and Dr. Maraganore disclaim beneficial ownership over the shares held by the Reporting Person, except to the extent of their respective proportionate pecuniary interests therein.

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