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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549
 
 FORM 10-Q
 þ
    
    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
   o
    
    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
1934
 
 0-28298
 ONYX PHARMACEUTICALS, INC.
  Delaware
    
    94-3154463(State or other jurisdiction of
    
    (I.R.S. Employer ID Number)incorporation or organization)
 
 
  þ o
  þ o




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ONYX PHARMACEUTICALS, INC.
 INDEX
  
 PART I: FINANCIAL INFORMATION
PageItem 1.Financial Statements (Unaudited)Condensed Balance Sheets  June 30, 2005 and December 31, 2004
3Condensed Statements of Operations  Three and six months ended June 30, 2005 and 2004
4Condensed Statements of Cash Flows  Six months ended June 30, 2005 and 2004
5Notes to Condensed Financial Statements
6Item 2.Managements Discussion and Analysis of Financial Condition and Results of Operations
9Item 3.Quantitative and Qualitative Disclosures About Market Risk
25Item 4.Controls and Procedures
26PART II: OTHER INFORMATIONItem 1.Legal Proceedings
27Item 2.Unregistered Sales of Equity Securities and Use of Proceeds
27Item 3.Defaults Upon Senior Securities
27Item 4.Submission of Matters to a Vote of Security Holders
27Item 5.Other Information
27Item 6.Exhibits
27SIGNATURESEXHIBIT 31.1EXHIBIT 32.1
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ONYX PHARMACEUTICALS, INC.
 
 PART I: FINANCIAL INFORMATION
 
 Item 1. Financial Statements (Unaudited)
 
 CONDENSED BALANCE SHEETS
 June 30,
    
    December 31,2005
    
    2004(Unaudited)
    
    (Note 1)(In thousands)ASSETSCurrent assets:Cash and cash equivalents
    
    $
    18,071
    
    
    $
    74,243Marketable securities
    
    
    159,281
    
    
    
    135,381Receivable from collaboration partner
    
    
    3,411
    
    
    
    1,029Other current assets
    
    
    4,107
    
    
    
    2,778Total current assets
    
    
    184,870
    
    
    
    213,431Property and equipment, net
    
    
    1,577
    
    
    
    1,623Other assets
    
    
    90
    
    
    
    492$
    186,537
    
    
    $
    215,546LIABILITIES AND STOCKHOLDERS EQUITYCurrent liabilities:Accounts payable
    
    $
    850
    
    
    $
    1,038Payable to collaboration partner
    
    
    13,736
    
    
    
    11,520Accrued liabilities
    
    
    4,287
    
    
    
    1,895Accrued compensation
    
    
    906
    
    
    
    910Accrued restructuring
    
    
    
    
    
    
    195Total current liabilities
    
    
    19,779
    
    
    
    15,558Advance from collaboration partner
    
    
    20,000
    

    
    
    20,000Commitments and contingenciesStockholders equity:Common stock
    
    
    35
    
    
    
    35Additional paid-in capital
    
    
    432,134
    
    
    
    430,966Accumulated other comprehensive loss
    
    
    (534
    )
    
    
    (377
    )Accumulated deficit
    
    
    (284,877
    )
    
    
    (250,636
    )Total stockholders equity
    
    
    146,758
    
    
    
    179,988$
    186,537
    
    
    $
    215,546
  3




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ONYX PHARMACEUTICALS, INC.
 
 CONDENSED STATEMENTS OF OPERATIONS
 Three Months Ended
    
    Six Months EndedJune 30,
    
    June 30,2005
    
    2004
    
    2005
    
    2004(In thousands, except per share amounts)Revenue:License fee
    
    $
    
    
    
    $
    
    
    
    $
    1,000
    
    
    $
    Operating expenses:Research and development
    
    
    12,079
    
    
    
    9,795
    
    
    
    25,611
    
    
    
    16,410Marketing
    
    
    5,362
    
    
    
    1,471
    
    
    
    7,316
    
    
    
    1,760General and administrative
    
    
    2,478
    
    
    
    2,278
    
    
    
    5,324
    
    
    
    4,079Restructuring
    
    
    
    
    
    
    258
    
    
    
    
    
    
    
    258Total operating expenses
    
    
    19,919
    
    
    
    13,802
    
    
    
    38,251
    
    
    
    22,507Loss from operations
    
    
    (19,919
    )
    
    
    (13,802
    )
    
    
    (37,251
    )
    
    
    (22,507
    )Interest income and (expense), net
    
    
    1,403
    
    
    
    696
    
    
    
    2,635
    
    
    
    1,220Other income
    
    
    375
    
    
    
    
    
    
    
    375
    
    
    
    Net loss
    
    $
    (18,141
    )
    
    $
    (13,106
    )
    
    $
    (34,241
    )
    
    $
    (21,287
    )Basic and diluted net loss per share
    
    $
    (0.51
    )
    
    $
    (0.38
    )
    
    $
    (0.97
    )
    
    $
    (0.63
    )Shares used in computing basic and
diluted net loss per share
    
    
    35,313
    
    
    
    34,723
    
    
    
    35,293
    
    
    
    33,639
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ONYX PHARMACEUTICALS, INC.
 
 CONDENSED STATEMENTS OF CASH FLOWS
 Six Months EndedJune 30,2005
    
    2004( In thousands)Cash flows from operating activities:Net loss
    
    $
    (34,241
    )
    
    $
    (21,287
    )Adjustments to reconcile net loss to net cash used
in operating activities:Depreciation and amortization
    
    
    278
    
    
    
    85Gain on sale of investment
    
    
    (375
    )
    
    
    Noncash restructuring charges
    
    
    
    
    
    
    258Gain on sale of fixed assets
    
    
    (6
    )
    
    
    Forgiveness of note receivable
    
    
    
    
    
    
    8Stock-based compensation to consultants
    
    
    355
    
    
    
    1,037Changes in assets and liabilities:Receivable from collaboration partner
    
    
    (2,382
    )
    
    
    (638
    )Other current assets
    
    
    (954
    )
    
    
    (1,166
    )Other assets
    
    
    402
    
    
    
    (3
    )Accounts payable
    
    
    (188
    )
    
    
    151Accrued liabilities
    
    
    2,197
    
    
    
    (235
    )Payable to collaboration partner
    
    
    2,216
    
    
    
    1,600Accrued compensation
    
    
    (4
    )
    
    
    (177
    )Net cash used in operating activities
    
    
    (32,702
    )
    
    
    (20,367
    )Cash flows from investing activities:Purchases of marketable securities
    
    
    (160,261
    )
    
    
    (98,386
    )Maturities of marketable securities
    
    
    136,204
    
    
    
    21,954Capital expenditures
    
    
    (232
    )
    
    
    (68
    )Proceeds from sale of fixed assets
    
    
    6
    
    
    
    451Net cash used in investing activities
    
    
    (24,283
    )
    
    
    (76,049
    )Cash flows from financing activities:Net proceeds from issuances of common stock
    
    
    813
    
    
    
    152,182Net cash provided by financing activities
    
    
    813
    
    
    
    152,182Net increase (decrease) in cash and cash equivalents
    
    
    (56,172
    )
    
    
    55,766Cash and cash equivalents at beginning of period
    
    
    74,243
    
    
    
    55,312Cash and cash equivalents at end of period
    
    $
    18,071
    
    
    $
    111,078
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ONYX PHARMACEUTICALS, INC.
 
 NOTES TO CONDENSED FINANCIAL STATEMENTS
June 30, 2005
(Unaudited)
 Note 1. Basis of Presentation
    Note 2. Stock-Based Compensation
 Accounting for Stock Issued to Employees Accounting for Stock-Based Compensation,
  Three Months Ended
    
    Six Months EndedJune 30,
    
    June 30,2005
    
    2004
    
    2005
    
    2004Risk-free interest rate
    
    
    3.92
    %
    
    
    3.24
    %
    
    
    3.61
    %
    
    
    2.83
    %Expected life
    
    3.9 years
    
    3.8 years
    
    3.8 years
    
    3.7 yearsExpected volatility
    
    
    0.73
    
    
    
    0.58
    
    
    
    0.76
    
    
    
    0.59Expected dividends
    
    None
    
    None
    
    None
    
    NoneWeighted average option fair value
    
    $
    16.88
    
    
    $
    18.12
    
    
    $
    15.36
    
    
    $
    17.60
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ONYX PHARMACEUTICALS, INC.
  Three Months Ended
    
    Six Months EndedJune 30,
    
    June 30,2005
    
    2004
    
    2005
    
    2004(In thousands, except per share amounts)Net loss  as reported
    
    $
    (18,141
    )
    
    $
    (13,106
    )
    
    $
    (34,241
    )
    
    $
    (21,287
    )Deduct: Total stock-based employee compensation
determined under the fair value based method for
all awards, net of related tax effects
    
    
    (3,297
    )
    
    
    (1,138
    )
    
    
    (5,845
    )
    
    
    (1,644
    )Pro forma net loss
    
    $
    (21,438
    )
    
    $
    (14,244
    )
    
    $
    (40,086
    )
    
    $
    (22,931
    )Net loss per share:Basic and diluted net loss per share  as reported
    
    $
    (0.51
    )
    
    $
    (0.38
    )
    
    $
    (0.97
    )
    
    $
    (0.63
    )Basic and diluted net loss per share  pro forma
    
    $
    (0.61
    )
    
    $
    (0.41
    )
    
    $
    (1.14
    )
    
    $
    (0.68
    )
 Note 3. Revenue
  Note 4. Net Loss Per Share
  Note 5. Comprehensive Loss
  Three Months Ended
    
    Six Months EndedJune 30,
    
    June 30,2005
    
    2004
    
    2005
    
    2004(In thousands)Net loss  as reported
    
    $
    (18,141
    )
    
    $
    (13,106
    )
    
    $
    (34,241
    )
    
    $
    (21,287
    )Other comprehensive loss:Net unrealized gain
(loss) on
available-for-sale
securities
    
    
    218
    
    
    
    (381
    )
    
    
    (157
    )
    
    
    (353
    )Comprehensive loss
    
    $
    (17,923
    )
    
    $
    (13,487
    )
    
    $
    (34,398
    )
    
    $
    (21,640
    )
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ONYX PHARMACEUTICALS, INC.
 Note 6. Restructuring
  Note 7. Recent Accounting Development
 Share-Based Payment Accounting for Stock-Based
Compensation Statement of Cash Flows
    Note 8. Investment in Syrrx Inc.
  Note 9. Subsequent Event
  8




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ONYX PHARMACEUTICALS, INC.
 
 Item 2. Managements Discussion and Analysis of Financial Condition and Results of
Operations
 The following Managements Discussion and Analysis of Financial Condition and Results of
Operations contains forward-looking statements that involve risks and uncertainties. We use words
such as may, will, expect, anticipate, estimate, intend, plan, predict,
potential, believe, should and similar expressions to identify forward-looking statements.
These statements appearing throughout our Form 10-Q are statements regarding our intent, belief, or
current expectations, primarily regarding our operations. You should not place undue reliance on
these forward-looking statements, which apply only as of the date of this Form 10-Q. Our actual
results could differ materially from those anticipated in these forward-looking statements for many
reasons, including those set forth under Business Risks.
 Overview
 changing the way cancer is treated. TM
      9




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ONYX PHARMACEUTICALS, INC.
     Critical Accounting Policies and the Use of Estimates
  Recent Accounting Development
 Share-Based Payment Accounting for Stock-Based Compensation Accounting for Stock Issued to Employees Statement of Cash Flows
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ONYX PHARMACEUTICALS, INC.
  1.
    
    A modified prospective method in which compensation cost is recognized beginning with
the effective date (a) based on the requirements of SFAS 123(R) for all share-based payments
granted after the effective date and (b) based on the requirements of SFAS 123 for all
awards granted to employees prior to the effective date of SFAS 123(R) that remain unvested
on the effective date.2.
    
    A modified retrospective method which includes the requirements of the modified
prospective method described above, but also permits entities to restate based on the
amounts previously recognized under SFAS 123 for purposes of pro forma disclosures either
(a) all prior periods presented or (b) prior interim periods of the year of adoption.
  Results of Operations
 Three and six months ended June 30, 2005 and 2004
 Revenue
  Research and Development Expenses
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ONYX PHARMACEUTICALS, INC.
   Research and Development ExpensesFor the Three Months
    
    For the Six MonthsEnded June 30,
    
    Ended June 30,Phase ofDevelopment Collabo-
    
    EstimatedProduct

    Description
    

    rator
    
    Completion
    
    2005
    
    2004
    
    2005
    
    2004(In thousands)Sorafenib

    Small molecule
multi-kinase
inhibitor of tumor
cell proliferation
and angiogenesis,
targeting RAF
kinase, VEGFR-2,
PDGFR-ß, KIT, and
FLT-3

    
    Bayer
    
    Phase I  2004
Phase IIUnknown
Phase IIIUnknown
    
    $
    12,032
    
    
    $
    9,197
    
    
    $
    25,164
    
    
    $
    14,792Therapeutic Virus
Programs

    Programs
discontinued during
the second quarter
of 2003.

    
    
    
    
    
    
    47
    
    
    
    598
    
    
    
    447
    
    
    
    1,618Total Research and Development Costs

    
    
    
    
    $
    12,079
    
    
    $
    9,795
    
    
    $
    25,611
    
    
    $
    16,410
 Marketing Expenses
  General and Administrative Expenses
  Restructuring
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ONYX PHARMACEUTICALS, INC.
  Interest Income and (Expense), net
  Other Income
  Liquidity and Capital Resources
     Business Risks
 13




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ONYX PHARMACEUTICALS, INC.
 Sorafenib (formerly known as BAY 43-9006) is our only product candidate currently in Phase II and
Phase III clinical development, and our ability to promote additional candidates to clinical
development is constrained. If sorafenib is not successfully commercialized, we may be unable to
identify and promote alternative product candidates and our business would fail.
  Our clinical trial of sorafenib in kidney cancer may not yield statistically significant overall
survival data, which may negatively impact the commercialization of sorafenib.
    We expect the number of therapies available for the treatment of kidney cancer could rapidly
increase, which could harm the prospects for sorafenib in this indication.
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ONYX PHARMACEUTICALS, INC.
   If our clinical trials fail to demonstrate that sorafenib is safe and effective for cancer types
other than kidney cancer, we will be unable to broadly commercialize sorafenib as a treatment for
cancer, and our business may fail.
    15




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ONYX PHARMACEUTICALS, INC.
  We are dependent upon our collaborative relationship with Bayer to develop, manufacture and
commercialize sorafenib and to obtain regulatory approval. There may be circumstances that delay or
prevent the development and commercialization of sorafenib.
        
    
    the amount and timing of expenditure of resources can vary because of decisions by Bayer;
    
    possible disagreements as to development plans, including clinical trials or regulatory approval strategy;
    
    the right of Bayer to terminate its collaboration agreement with us on limited notice and
for reasons outside our control;
    
    loss of significant rights if we fail to meet our obligations under the collaboration agreement;
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ONYX PHARMACEUTICALS, INC.
 
    
    withdrawal of support by Bayer following the development or acquisition by it of competing products; and
    
    possible disagreements with Bayer regarding the collaboration agreement or ownership of proprietary rights.
  If Bayers business strategy changes, it may adversely affect our collaborative relationship.
  Provisions in our collaboration agreement with Bayer may prevent or delay a change in control.
  Our clinical trials could take longer to complete than we project or may not be completed at all.
    We face intense competition and rapid technological change, and many of our competitors have
substantially greater managerial resources than we have.
  17




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ONYX PHARMACEUTICALS, INC.
 TM TM
   
    
    developing products;
    
    undertaking preclinical testing and human clinical trials;
    
    obtaining FDA and other regulatory approvals of products; and
    
    manufacturing and marketing products.
     We will need substantial additional funds, and our future access to capital is uncertain.
  
    
    the size and complexity of our sorafenib program;
    
    decisions made by Bayer and Onyx to alter the size, scope and schedule of clinical development;
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ONYX PHARMACEUTICALS, INC.
 
    
    our receipt of milestone-based payments;
    
    the ability to manufacture sufficient drug supply to complete clinical trials;
    
    progress with clinical trials;
    
    the time and costs involved in obtaining regulatory approvals;
    
    the cost involved in enforcing patent claims against third parties and defending claims
by third parties (both of which are shared with Bayer);
    
    the costs associated with acquisitions or licenses of additional products;
    
    competing technological and market developments; and
    
    product commercialization activities.
   We have a history of losses, and we expect to continue to incur losses.
   We do not have manufacturing expertise or capabilities and are dependent on Bayer to fulfill our
manufacturing needs, which could result in the delay of clinical trials or regulatory approval.
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ONYX PHARMACEUTICALS, INC.
  We have the right to copromote sorafenib in the United States, but we do not have significant
marketing or sales experience or capabilities.
   If we lose our key employees and consultants or are unable to attract or retain qualified
personnel, our business could suffer.
   We expect to significantly expand our sales and marketing capabilities, and any difficulties managing this growth could disrupt our operations.
  Even if our product candidates are approved, the market may not accept these products.
  20




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ONYX PHARMACEUTICALS, INC.
   
    
    rate of adoption by healthcare practitioners;
    
    types of cancer for which the product is approved;
    
    rate of a products acceptance by the target population;
    
    timing of market entry relative to competitive products;
    
    availability of alternative therapies;
    
    price of our product relative to alternative therapies;
    
    extent of marketing efforts by us and third-party distributors or agents retained by us; and
    
    side effects or unfavorable publicity concerning our products or similar products.
  We are subject to extensive government regulation, which can be costly, time consuming and subject
us to unanticipated delays.
    
    
    adversely affect the successful commercialization of sorafenib;
    
    impose costly procedures on us;
    
    diminish any competitive advantages that we may attain; and
    
    adversely affect our receipt of revenues or royalties.
 
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ONYX PHARMACEUTICALS, INC.
 
  We may not be able to protect our intellectual property or operate our business without
infringing upon the intellectual property rights of others.
  
    
    obtain patents;
    
    license technology rights from others;
    
    protect trade secrets;
    
    operate without infringing upon the proprietary rights of others; and
    
    prevent others from infringing on our proprietary rights.
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ONYX PHARMACEUTICALS, INC.
  We face product liability risks and may not be able to obtain adequate insurance.
   
    
    decreased demand for a product;
    
    injury to our reputation;
    
    withdrawal of clinical trial volunteers; and
    
    loss of revenues.
  Our stock price is volatile.
  
    
    interim or final results of, or speculation about, clinical trials from sorafenib;
    
    changes in the regulatory approval requirements;
    
    ability to accrue patients into clinical trials;
    
    success or failure in, or speculation about, obtaining regulatory approval by us or our competitors;
    
    public concern as to the safety and efficacy of our product candidates;
    
    developments in our relationship with Bayer;
    
    developments in patent or other proprietary rights;
    
    additions or departures of key personnel;
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ONYX PHARMACEUTICALS, INC.
 
    
    announcements by us or our competitors of technological innovations or new commercial therapeutic products;
    
    published reports by securities analysts;
    
    statements of governmental officials; and
    
    changes in healthcare reimbursement policies.
 Existing stockholders have significant influence over us.
   We are at risk of securities class action litigation due to our expected stock price volatility.
  Provisions in Delaware law, our charter and executive change of control agreements we have entered
into may prevent or delay a change of control.
  
    
    the board of directors approved the transaction where the stockholder acquired 15 percent
or more of the corporations stock;
    
    after the transaction in which the stockholder acquired 15 percent or more of the
corporations stock, the stockholder owned at least 85 percent of the corporations
outstanding voting stock, excluding shares owned by directors, officers and employee stock
plans in which employee participants do not have the right to determine confidentially
whether shares held under the plan will be tendered in a tender or exchange offer; or
    
    on or after this date, the merger or sale is approved by the board of directors and the
holders of at least two-thirds of the outstanding voting stock that is not owned by the
stockholder.
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ONYX PHARMACEUTICALS, INC.
  
    
    our board is classified into three classes of directors as nearly equal in size as
possible with staggered three-year terms;
    
    the authority of our board to issue up to 5,000,000 shares of preferred stock and to
determine the price, rights, preferences and privileges of these shares, without stockholder
approval;
    
    all stockholder actions must be effected at a duly called meeting of stockholders and not
by written consent;
    
    special meetings of the stockholders may be called only by the chairman of the board, the
chief executive officer, the board or ten percent or more of the stockholders entitled to
vote at the meeting; and
    
    no cumulative voting.
   
 Item 3. Quantitative and Qualitative Disclosures About Market Risk
   June 30, 2005
    
    December 31, 2004Average
    
    
    
    
    
    
    
    
    
    AverageFair Value
    
    Interest
    
    
    
    
    
    Fair Value
    
    InterestMaturity
    
    (In millions)
    
    Rate
    
    Maturity
    
    (In millions)
    
    RateCash equivalents, fixed rate
    
    0  2 months
    
    $
    18.1
    
    
    
    2.86
    %
    
    0  2 months
    
    $
    74.2
    
    
    
    2.09
    %Marketable securities,
fixed rate
    
    0  21 months
    
    $
    159.3
    
    
    
    3.03
    %
    
    0  16 months
    
    $
    135.4
    
    
    
    2.18
    %
  25




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ONYX PHARMACEUTICALS, INC.
 
 Item 4. Controls and Procedures
 Inherent Limitations on Effectiveness of Controls:
 Evaluation of Disclosure Controls and Procedures:
 Changes in Internal Control over Financial Reporting:
 26




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ONYX PHARMACEUTICALS, INC.
 
 PART II: OTHER INFORMATION
 
 Item 1. Legal Proceedings
 Not applicable.
 
 Item 2. Unregistered Sales of Equity Securities and Use of Proceeds
 Not applicable.
 
 Item 3. Defaults Upon Senior Securities
 Not applicable.
 
 Item 4. Submission of Matters to a Vote of Security Holders
  (a)
    
    Each of the nominees to the Board of Directors was elected to serve until our
annual meeting of stockholders in 2008. The nominees were: Magnus Lundberg; 27,291,723
common shares for, none against and 285,481 withheld; and Hollings C. Renton;
27,283,958 common shares for, none against and 293,246 withheld. The term of office of
directors Paul Goddard, Antonio J. Grillo-López and Wendell D. Wierenga continues until
our annual meeting of stockholders in 2006. The term of office of directors Nicole
Vitullo and Thomas G. Wiggans continues until our annual meeting of stockholders in
2007.(b)
    
    The stockholders approved the adoption of the 2005 Equity Incentive Plan. The
2005 Equity Incentive Plan is intended as the successor to, and a continuation of, our
1996 Equity Incentive Plan and our 1996 Non-Employee Directors Stock Option Plan:
14,888,065 common shares for, 1,510,520 against, 17,304 abstaining and 11,161,315
broker non-votes.(c)
    
    The stockholders ratified the selection of Ernst & Young LLP as our independent
registered public accounting firm for the fiscal year ending December 31, 2005:
27,503,887 common shares for, 62,926 against and 10,391 abstaining.
 
 Item 5. Other Information
 Not applicable.
 
 Item 6. Exhibits
 3.1
    
    Restated Certificate of Incorporation of the Company. (1)3.2
    
    Bylaws of the Company. (1)3.3
    
    Certificate of Amendment to Amended and Restated Certificate of Incorporation. (2)4.1
    
    Reference is made to Exhibits 3.1, 3.2 and 3.3.4.2
    
    Specimen Stock Certificate. (1)10.45
    
    Onyx Pharmaceuticals, Inc. 2005 Equity Incentive Plan. (3)31.1
    
    Certification required by Rule 13a-14(a) or Rule 15d-14(a).32.1
    
    Certifications required by Rule 13a-14(b) or Rule 15d-14(b) and Section 1350 of
Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350). (4)
 27




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##### Table of Contents



ONYX PHARMACEUTICALS, INC.
 
 (1)
    
    Filed as an exhibit to the registrants Registration Statement on Form SB-2 (No.
333-3176-LA).(2)
    
    Filed as an exhibit to the registrants Quarterly Report on Form 10-Q for the quarter ended
June 30, 2000.(3)
    
    Filed as an exhibit to the registrants Current Report
on Form 8-K filed on June 7, 2005.(4)
    
    This certification accompanies the Quarterly Report on Form 10-Q to which it relates, is
not deemed filed with the Securities and Exchange Commission and is not to be incorporated by
reference into any filing of Onyx Pharmaceuticals, Inc. under the Securities Act of 1933, as
amended or the Securities Exchange Act of 1934, as amended (whether made before or after the
date of the Quarterly Report on Form 10-Q), irrespective of any general incorporation
language contained in such filing. 28




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##### Table of Contents



ONYX PHARMACEUTICALS, INC.
 
 SIGNATURES
  ONYX PHARMACEUTICALS, INC.Date:  August 9, 2005
    By:
    /s/ Hollings C. RentonHollings C. RentonChairman of the Board,
    President and Chief Executive Officer
    (Principal Executive and Financial Officer) Date:  August 9, 2005
    By:
    /s/ Marilyn E. WortzmanMarilyn E. WortzmanVice President, Finance and Administration
    (Principal Accounting Officer) 29




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##### Table of Contents



ONYX PHARMACEUTICALS, INC.
 
 EXHIBIT INDEX
 3.1
    
    Restated Certificate of Incorporation of the Company. (1)3.2
    
    Bylaws of the Company. (1)3.3
    
    Certificate of Amendment to Amended and Restated Certificate of Incorporation. (2)4.1
    
    Reference is made to Exhibits 3.1, 3.2 and 3.3.4.2
    
    Specimen Stock Certificate. (1)10.45
    
    Onyx Pharmaceuticals, Inc. 2005 Equity Incentive Plan. (3)31.1
    
    Certification required by Rule 13a-14(a) or Rule 15d-14(a).32.1
    
    Certifications required by Rule 13a-14(b) or Rule 15d-14(b) and Section 1350 of
Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350). (4)
 
 (1)
    
    Filed as an exhibit to the registrants Registration Statement on Form SB-2 (No.
333-3176-LA).(2)
    
    Filed as an exhibit to the registrants Quarterly Report on Form 10-Q for the quarter
ended June 30, 2000.(3)
    
    Filed as an exhibit to the registrants Current Report
on Form 8-K filed on June 7,
2005.(4)
    
    This certification accompanies the Quarterly Report on Form 10-Q to which it relates, is
not deemed filed with the Securities and Exchange Commission and is not to be incorporated by
reference into any filing of Onyx Pharmaceuticals, Inc. under the Securities Act of 1933, as
amended or the Securities Exchange Act of 1934, as amended (whether made before or after the
date of the Quarterly Report on Form 10-Q), irrespective of any general incorporation
language contained in such filing. 30