SEC Form 3 
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
or Section 30(h) of the Investment Company Act of 1940 	  
OMB APPROVAL
OMB Number:	3235-0104	
Estimated average burden	
hours per response:	0.5	

	
1. Name and Address of Reporting Person*
BIOGEN IDEC INC	

(Last)	(First)	(Middle)	
14 CAMBRIDGE CENTER	

(Street) 
CAMBRIDGE	MA	02142	

(City)	(State)	(Zip)	
	2. Date of Event Requiring Statement (Month/Day/Year)
09/27/2005 	3. Issuer Name and Ticker or Trading Symbol 
SUNESIS PHARMACEUTICALS INC [ SNSS ] 		
		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 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 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) 	
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: 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 C-1 Preferred Stock	(1) 	(1) 	Common Stock	1,250,000	0	I(2) 	By Biogen Idec MA Inc.	
Series C-2 Preferred Stock	(1) 	(1) 	Common Stock	2,916,667	0	I(2) 	By Biogen Idec MA Inc.	
1. Name and Address of Reporting Person*
BIOGEN IDEC INC	

(Last)	(First)	(Middle)	
14 CAMBRIDGE CENTER	

(Street) 
CAMBRIDGE	MA	02142	

(City)	(State)	(Zip)	
	
1. Name and Address of Reporting Person*
BIOGEN IDEC MA INC	

(Last)	(First)	(Middle)	
14 CAMBRIDGE CENTER	

(Street) 
CAMBRIDGE	MA	02142	

(City)	(State)	(Zip)	
	
Explanation of Responses:	
1. The Issuer's Series C-1 and Series C-2 Preferred Stock had no conversion price, exercise date or expiration date. Upon the effectiveness of the Issuer's initial public offering (the "IPO"), each share of Series C-1 and Series C-2 Preferred Stock was converted into Common Stock at a conversion price determined as of the effective date of the IPO.	
2. The Issuer's Series C-1 and Series C-2 Preferred Stock was owned directly by Biogen Idec MA Inc., a wholly owned subsidiary of Biogen Idec Inc.	
Remarks:	
	
	/s/ Michael F. Phelps, Vice President, Treasurer, Biogen Idec Inc.	02/14/2006	
	/s/ Michael F. Phelps, Vice President, Treasurer, Biogen Idec MA Inc.	02/14/2006	
	** 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 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).	
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.	
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.