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
X	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* ROBIN HOWARD W (Last) (First) (Middle) 185 BERRY STREET SUITE 6504 (Street) SAN FRANCISCO CA 94107 (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) X Director 10% Owner X Officer (give title below) Other (specify below) CEO & President
	3. Date of Earliest Transaction (Month/Day/Year) 12/29/2006
	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	12/29/2006		D		22,125	D	(1)	0	D
Common Stock	12/29/2006		D		833	D	(1)	0	I	by Trust

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
Incentive Stock Option (right to buy)	$1.86	12/29/2006		D			4,167	(2)	12/18/2012	Common Stock	4,167	(2)	0	D
Incentive Stock Option (right to buy)	$2.1	12/29/2006		D			148,123	(3)	02/11/2013	Common Stock	148,123	(3)	0	D
Incentive Stock Option (right to buy)	$3.07	12/29/2006		D			2,084	(4)	02/03/2015	Common Stock	2,084	(4)	0	D
Incentive Stock Option (right to buy)	$4.68	12/29/2006		D			7,377	(5)	06/04/2012	Common Stock	7,377	(5)	0	D
Incentive Stock Option (right to buy)	$5.06	12/29/2006		D			14,584	(6)	02/21/2016	Common Stock	14,584	(6)	0	D
Incentive Stock Option (right to buy)	$5.15	12/29/2006		D			8	(7)	01/22/2014	Common Stock	8	(7)	0	D
Non-Qualified Stock Option (right to buy)	$1.86	12/29/2006		D			12,500	(8)	12/18/2012	Common Stock	12,500	(8)	0	D
Non-Qualified Stock Option (right to buy)	$2.1	12/29/2006		D			1,286,043	(9)	02/11/2013	Common Stock	1,286,043	(9)	0	D
Non-Qualified Stock Option (right to buy)	$3.07	12/29/2006		D			47,916	(10)	02/03/2015	Common Stock	47,916	(10)	0	D
Non-Qualified Stock Option (right to buy)	$4.62	12/29/2006		D			16,667	(11)	08/22/2012	Common Stock	16,667	(11)	0	D
Non-Qualified Stock Option (right to buy)	$4.68	12/29/2006		D			22,123	(12)	06/04/2012	Common Stock	22,123	(12)	0	D
Non-Qualified Stock Option (right to buy)	$5.06	12/29/2006		D			35,416	(13)	02/21/2016	Common Stock	35,416	(13)	0	D
Non-Qualified Stock Option (right to buy)	$5.15	12/29/2006		D			39,992	(14)	01/22/2014	Common Stock	39,992	(14)	0	D

Explanation of Responses:

1. The shares were disposed of pursuant to the merger agreement between Sirna Therapeutics, Inc, Merck & Co., Inc. and Spinnaker Acquisition Corp. in exchange for a cash payment of $13 per share.

2. The outstanding option, which provided for vesting in 4 equal annual installments begining on December 18, 2003, was canceled upon the close of the merger in exchange for a total cash payment of $46,420.38 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

3. The outstanding option, which provided for vesting of 20% beginning on April 21, 2004 and in equal monthly installments thereunder for the subsequent four years, was canceled upon the close of the merger in exchange for a total cash payment of $1,614,540.70 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

4. The outstanding option, which provided for vesting in 48 equal monthly installments begining on March 3, 2005, was canceled upon the close of the merger in exchange for a total cash payment of $20,694.12 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

5. The outstanding option, which provided for vesting in 4 equal annual installments begining on June 4, 2003, was canceled upon the close of the merger in exchange for a total cash payment of $61,376.64 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

6. The outstanding option, which provided for vesting in 48 equal monthly installments begining on March 21, 2006, was canceled upon the close of the merger in exchange for a total cash payment of $115,796.96 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

7. The outstanding option, which provided for vesting in 48 equal monthly installments begining on February 22, 2004, was canceled upon the close of the merger in exchange for a total cash payment of $62.80 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

8. The outstanding option, which provided for vesting in 4 equal annual installments begining on December 18, 2003, was canceled upon the close of the merger in exchange for a total cash payment of $139,250.00 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

9. The outstanding option, which provided for vesting of 20% beginning on April 21, 2004 and in equal monthly installments thereunder for the subsequent four years, was canceled upon the close of the merger in exchange for a total cash payment of $14,017,868.70 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

10. The outstanding option, which provided for vesting in 48 equal monthly installments begining on March 3, 2005, was canceled upon the close of the merger in exchange for a total cash payment of $475,805.88 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

11. The outstanding option, which provided for vesting in 2 equal annual installments begining on August 22, 2003, was canceled upon the close of the merger in exchange for a total cash payment of $139,669.46 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

12. The outstanding option, which provided for vesting in 4 equal annual installments begining on June 4, 2003, was canceled upon the close of the merger in exchange for a total cash payment of $184,063.36 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

13. The outstanding option, which provided for vesting in 48 equal monthly installments begining on March 21, 2006, was canceled upon the close of the merger in exchange for a total cash payment of $281,203.04 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

14. The outstanding option, which provided for vesting in 48 equal monthly installments begining on February 22, 2004, was canceled upon the close of the merger in exchange for a total cash payment of $313,937.20 representing the difference between the exercise price of the option value and the merger consideration of $13 per share.

	By: /s/ Bharat Chowrira For: Howard W. Robin	01/04/2007
	** Signature of Reporting Person	Date
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