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) 07/06/2005
	4. If Amendment, Date of 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

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	07/06/2005		P		1,237,582	A	$1.6	5,807,127	D(1)
Common	07/06/2005		P		12,418	A	$1.6	58,267	I(2)	By mRNA Fund II L.P.

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
Warrants (right to buy)	$1.92(3)	07/06/2005		P		445,529		(4)	(4)	Common Stock	445,529	(3)	445,529	D(1)
Warrants (right to buy)	$1.92(3)	07/06/2005		P		4,470		(4)	(4)	Common Stock	4,470	(3)	4,470	I(2)	By mRNA Fund II L.P.

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) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MRNA FUND II LP (Last) (First) (Middle) 222 BERKELEY ST. (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Securities Oxford Bioscience Partners IV L.P. ("Oxford IV") is irrevocably committed to acquire. By virtue of their relationship as affiliated limited partnerships, whose sole general partner shares individual general partners, Oxford IV and mRNA Fund II L.P. ("mRNA") may be deemed to share voting power and the power to direct the disposition of the shares which each partnership owns of record. The reporting persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interest therein.

2. Securities mRNA is irrevocably committed to acquire. By virtue of their relationship as affiliated limited partnerships, whose sole general partner shares individual general partners, Oxford IV and mRNA may be deemed to share voting power and the power to direct the disposition of the shares which each partnership owns of record. The reporting persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interest therein.

3. In the event that the shares of the Company's Common Stock are (i) terminated from registration under the Securities Act of 1933, as amended during the time in which the Company remains obligated to keep the registration statement (to be filed with respect to the shares issued in a private placement pursuant to a stock purchase agreement dated as of July 6, 2005) current, effective and free from any material misstatement or omission to state a material fact or (ii) delisted from the Nasdaq National Market, the Warrant Price then in effect at the time of such deregistration or delisting shall be reduced to $1.67 per share.

4. The warrant is exercisable from approximately January 2006 to the fifth anniversary of the date of grant.

Remarks:

	/s/ Jonathan J. Fleming, as general partner of the general partner of Oxford Bioscience Partners IV L.P.	07/08/2005
	/s/ Jonathan J. Fleming, as general partner of the general partner of mRNA Fund II L.P.	07/08/2005
	** Signature of Reporting Person	Date
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