SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* OXFORD BIOSCIENCE PARTNERS IV LP (Last) (First) (Middle) 222 BERKELEY ST. (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol SIRNA THERAPEUTICS INC [ RNAI ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 12/30/2004
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

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	12/30/2004		X		810,315	A	$2.52	4,569,545	D
Common Stock	12/30/2004		X		8,130	A	$2.52	45,849	I	By mRNA Fund II L.P.(1)

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 Securities Underlying Derivative Security (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: 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
Warrant (right to buy)	$2.52	12/30/2004		H			810,315	02/11/2003	02/11/2008	Common Stock	810,315	(2)	0	D
Warrant (right to buy)	$2.52	12/30/2004		P		810,315		12/30/2004	02/07/2005	Common Stock	810,315	(2)	810,315	D
Warrant (right to buy)	$3.85(3)	12/30/2004		P		891,346		12/30/2004	12/30/2009	Common Stock	891,346	(2)	1,701,661	D
Warrant (right to buy)	$2.52	12/30/2004		X			810,315	12/30/2004	02/07/2005	Common Stock	810,315	(2)	891,346	D
Warrant (right to buy)	$2.52	12/30/2004		H			8,130	02/11/2003	02/11/2008	Common Stock	8,130	(4)	0	I	By mRNA Fund II L.P.(1)
Warrant (right to buy)	$2.52	12/30/2004		P		8,130		12/30/2004	02/07/2005	Common Stock	8,130	(4)	8,130	I	By mRNA Fund II L.P.(1)
Warrant (right to buy)	$3.85(3)	12/30/2004		P		8,943		12/30/2004	12/30/2009	Common Stock	8,943	(4)	17,073	I	By mRNA Fund II L.P.(1)
Warrant (right to buy)	$2.52	12/30/2004		X			8,130	12/30/2004	02/07/2005	Common Stock	8,130	(4)	8,943	I	By mRNA Fund II L.P.(1)

Explanation of Responses:

1. The reporting person shares a common general partner with the partnership that owns the reported securities. The reporting person disclaims beneficial ownership of the reported securities.

2. The reporting person exchanged, in an issuer exchange, a warrant to purchase 810,315 shares of Common Stock for (i) a warrant to purchase 810,315 shares of Common Stock exercisable by payment with cash only and (ii) a warrant to purchase 891,346 shares of Common Stock exercisable by net issuance or by payment with cash.

3. The exercise price (subject to adjustment in the event of stock splits, reverse stock splits, stock dividends, recapitalizations, or similar events) is equal to (i) in the event of a private placement for the primary purpose of raising capital for the Company on or before June 30, 2005, the lower of $3.85 per share and the lowest price per share of Common Stock sold in any such private placement that closes after December 30, 200 and on or before June 30, 2005 or (ii) if no such private placement occurs by June 30, 2005, the lower of $3.85 per share and the average closing selling price of a share of Common Stock traded on the Nasdaq National Market, as quoted in The Wall Street Journal, over the 15-day period ending on June 30, 2005.

4. mRNA Fund II L.P. exchanged, in an issuer exchange, a warrant to purchase 8,130 shares of Common Stock for (i) a warrant to purchase 8,130 shares of Common Stock exercisable by payment with cash only and (ii) a warrant to purchase 8,943 shares of Common Stock exercisable by net issuance or by payment with cash.

Remarks:

	Mark Carthy, as general partner of the general partner of Oxford Bioscience Partners IV L.P.	01/04/2005
	** Signature of Reporting Person	Date
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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