S-8

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

ONYX PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware
(State of incorporation) 94-3154463
(I.R.S. Employer Identification No.)

2100 Powell Street
Emeryville, California 94608
(510) 597-6500
(Address and telephone number of Principal Executive Offices)

2005 EQUITY INCENTIVE PLAN
(Full title of the plan)

N. Anthony Coles, M.D.
President and Chief Executive Officer
Onyx Pharmaceuticals, Inc.
2100 Powell Street
Emeryville, California 94608
(510) 597-6500
(Name, address, and telephone number of agent for service)

Copies to:
Robert L. Jones, Esq.
Michael E. Tenta, Esq.
Cooley Godward Kronish LLP
Five Palo Alto Square
3000 El Camino Real
Palo Alto, California 94306-2155
(650) 843-5000

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer þ	Accelerated filer o	Non-accelerated filer o	Smaller reporting company o
	(Do not check if a smaller reporting company)

CALCULATION OF REGISTRATION FEE

			Proposed Maximum		Proposed Maximum
Title of Securities	Amount to be		Offering Price Per		Aggregate Offering		Amount of
To Be Registered	Registered (1)		Share (2)		Price (2)		Registration Fee
Common Stock, par value $0.001 per share		3,100,000	$	34.38	$	106,578,000	$	4,188.52

(1)

Pursuant to Rule 416(a) promulgated under the Securities Act of 1933, as amended (the “Securities Act”), this registration statement shall cover any additional shares of Common Stock which become issuable under the plan set forth herein by reason of any stock dividend, stock split, recapitalization or any other similar transaction without receipt of consideration which results in an increase in the number of shares of the registrant’s outstanding Common Stock.

(2)

Estimated solely for the purpose of calculating the amount of the registration fee pursuant to Rule 457(h) of the Securities Act. The offering price per share and aggregate offering price are based on the average of the high and low prices of the Registrant’s Common Stock as reported on the Nasdaq Global Market on May 9, 2008.

TABLE OF CONTENTS

EXHIBIT 5.1

EXHIBIT 23.1

PART II

EXPLANATORY NOTE

          This Registration Statement on Form S-8 is being filed for the purpose of registering an additional 3,100,000 shares of Onyx Pharmaceuticals, Inc.’s (the “Company”) Common Stock to be issued pursuant to the Company’s 2005 Equity Incentive Plan, as amended.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

          The following documents filed by Onyx Pharmaceuticals, Inc. with the Securities and Exchange Commission are incorporated by reference into this Registration Statement:

a)	The Company’s Registration Statement on Form S-8 filed on June 23, 2005, under the Securities Act of 1933, as amended (file No. 333-126089).
b)	The Company’s Registration Statement on Form S-8 filed on May 30, 2006, under the Securities Act of 1933, as amended (file No. 333-134567).
c)	The Company’s Registration Statement on Form S-8 filed on May 25, 2007, under the Securities Act of 1933, as amended (file No. 333-143309).

          All reports and other documents subsequently filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part of this registration statement from the date of the filing of such reports and documents.

II-1

EXHIBITS

Exhibit
Number
4.1(1)	Restated Certificate of Incorporation.
4.2(4)	Bylaws of the Company.
4.3(2)	Certificate of Amendment to Amended and Restated Certificate of Incorporation.
4.4(3)	Certificate of Amendment to Amended and Restated Certificate of Incorporation.
4.5(1)	Specimen Stock Certificate.
5.1	Opinion of Cooley Godward Kronish LLP.
23.1	Consent of Independent Registered Public Accounting Firm.
23.2	Consent of Cooley Godward Kronish LLP. Reference is made to Exhibit 5.1.
24.1	Power of Attorney. Reference is made to the signature pages.
99.1(4)	2005 Equity Incentive Plan.

(1)	Previously filed as an exhibit to Onyx’s Registration Statement on Form SB-2 (No. 333-3176-LA), and incorporated herein by reference.
(2)	Previously filed as an exhibit to Onyx’s Quarterly Report on Form 10-Q for the Quarter ended June 30, 2000, and incorporated herein by reference.
(3)	Previously filed as an exhibit to Onyx’s Registration Statement on Form S-8 (No. 333- 134565), filed on May 30, 2006 and incorporated herein by reference.
(4)	Previously filed as an exhibit to Onyx’s Current Report on Form 8-K filed on May 15, 2008.

II-2

SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Emeryville, State of California, on the 14th day of May, 2008.

ONYX PHARMACEUTICALS, INC.
By:	/s/ N. Anthony Coles
	N. Anthony Coles
	President and Chief Executive Officer

POWER OF ATTORNEY

          KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints N. Anthony Coles, M.D. and Gregory W. Schafer, and each or any one of them, his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his or her substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

          Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

Signature	Title	Date
/s/ N. Anthony Coles N. Anthony Coles	Director, President and Chief Executive Officer (Principal Executive Officer)	May 14, 2008
/s/ Gregory W. Schafer Gregory W. Schafer	Vice President and Chief Financial Officer (Principal Financial and Accounting Officer)	May 14, 2008
/s/ Paul Goddard Paul Goddard	Lead Director	May 14, 2008
/s/ Antonio Grillo-López Antonio Grillo-López	Director	May 14, 2008
/s/ Magnus Lundberg Magnus Lundberg	Director	May 14, 2008
/s/ Corinne Lyle Corinne Lyle	Director	May 14, 2008
/s/ Wendell Wierenga Wendell Wierenga	Director	May 14, 2008
/s/ Thomas G. Wiggans Thomas G. Wiggans	Director	May 14, 2008

II-3

EXHIBIT INDEX

Exhibit
Number
4.1(1)	Restated Certificate of Incorporation.
4.2(4)	Bylaws of the Company.
4.3(2)	Certificate of Amendment to Amended and Restated Certificate of Incorporation.
4.4(3)	Certificate of Amendment to Amended and Restated Certificate of Incorporation.
4.5(1)	Specimen Stock Certificate.
5.1	Opinion of Cooley Godward Kronish LLP.
23.1	Consent of Independent Registered Public Accounting Firm.
23.2	Consent of Cooley Godward Kronish LLP. Reference is made to Exhibit 5.1.
24.1	Power of Attorney. Reference is made to the signature pages.
99.1(4)	2005 Equity Incentive Plan.

(1)	Previously filed as an exhibit to Onyx’s Registration Statement on Form SB-2 (No. 333-3176-LA), and incorporated herein by reference.
(2)	Previously filed as an exhibit to Onyx’s Quarterly Report on Form 10-Q for the Quarter ended June 30, 2000, and incorporated herein by reference.
(3)	Previously filed as an exhibit to Onyx’s Registration Statement on Form S-8 (No. 333- 134565), filed on May 30, 2006 and incorporated herein by reference.
(4)	Previously filed as an exhibit to Onyx’s Current Report on Form 8-K filed on May 15, 2008.

EX-5.1

Exhibit 5.1

[Cooley Godward Kronish LLP Letterhead]

May 14, 2008

Onyx Pharmaceuticals, Inc.
2100 Powell Street
Emeryville, California 94608

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the filing by Onyx Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, of a Registration Statement on Form S-8 (the “Registration Statement”) with the Securities and Exchange Commission covering the offering of up to 3,100,000 shares of the Company’s Common Stock, par value $0.001 per share (the “Shares”), issuable pursuant to the Company’s 2005 Equity Incentive Plan, as amended (the “Plan”).

In connection with this opinion, we have examined the Registration Statement and related Prospectus, your Amended and Restated Certificate of Incorporation, as amended, and Bylaws, and such other documents, records, certificates, memoranda and other instruments as we deem necessary as a basis for this opinion. We have assumed the genuineness and authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies thereof, and the due execution and delivery of all documents where due execution and delivery are a prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold and issued in accordance with the Plan, the Registration Statement and related Prospectus, will be validly issued, fully paid, and nonassessable (except as to shares issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration Statement.

Very truly yours,

Cooley Godward Kronish LLP
By:	/s/ Michael E. Tenta
	Michael E. Tenta

EX-23.1

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

     We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2005 Equity Incentive Plan, as amended, of Onyx Pharmaceuticals, Inc. of our reports dated February 27, 2008 with respect to the financial statements of Onyx Pharmaceuticals, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2007, and the effectiveness of internal control over financial reporting of Onyx Pharmaceuticals, Inc., filed with the Securities and Exchange Commission.

/s/ ERNST & YOUNG LLP  

Palo Alto, California
May 14, 2008