##### Table of Contents





As filed with the Securities and Exchange
    Commission on June 23, 2011
 Registration
    No. 333-
    UNITED STATES SECURITIES AND
    EXCHANGE COMMISSION
 Washington, D.C.
    20549
      Form S-1
 REGISTRATION
    STATEMENT
 UNDER
 THE SECURITIES ACT OF
    1933
      CLOVIS ONCOLOGY, INC.
 (Exact name of registrant as
    specified in its charter)
      Delaware

2834

90-0475355(State or other jurisdiction
    of
    incorporation or organization)

(Primary Standard Industrial
    Classification Code Number)

(I.R.S. Employer
    Identification Number)   2525 28th Street,
    Suite 100
 Boulder, Colorado
    80301
 (303) 625-5000
  (Address, including zip code,
    and telephone number, including area code, of registrants
    principal executive offices)
  Patrick J. Mahaffy
 President and Chief Executive
    Officer
 Clovis Oncology, Inc.
 2525 28th Street,
    Suite 100
 Boulder, Colorado
    80301
 (303) 625-5000
  (Name, address, including zip
    code, and telephone number, including area code, of agent for
    service)
  Copies to:
  Peter H. Jakes, Esq.
    William H. Gump, Esq.
    Willkie Farr & Gallagher LLP
    787 Seventh Avenue
    New York, New York 10019(212) 728-8000

Cheston J. Larson, Esq.
    Divakar Gupta, Esq.
    Latham & Watkins LLP
    12636 High Bluff Drive, Suite 400
    San Diego, California 92130
    (858) 523-5400       Approximate date of commencement of proposed sale to the
    public:
  o
  o
  o
  o
  12b-2
  Large
    accelerated
    filer o
    Accelerated
    filer o
    Non-accelerated
    filer þ
    Smaller reporting
    company o (Do not check if a smaller
    reporting company)
  CALCULATION
    OF REGISTRATION FEE
  Proposed Maximum


Amount ofTitle of Each Class of


Aggregate Offering


RegistrationSecurities to be Registered


Price(1)(2)


FeeCommon Stock, par value $0.001 per share


$149,500,000


$17,357  (1)
    
    Estimated solely for purposes of
    determining the registration fee in accordance with
    Rule 457(o) under the Securities Act of 1933, as amended.(2)
    
    Includes shares of common stock
    which may be purchased by the underwriters to cover
    over-allotments, if any.      The Registrant hereby amends this Registration Statement on
    such date or dates as may be necessary to delay its effective
    date until the Registrant shall file a further amendment which
    specifically states that this Registration Statement shall
    thereafter become effective in accordance with Section 8(a)
    of the Securities Act of 1933, as amended, or until this
    Registration Statement shall become effective on such date as
    the Securities and Exchange Commission, acting pursuant to said
    Section 8(a), may determine.




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##### Table of Contents



The
information in this prospectus is not complete and may be
changed. We may not sell these securities until the registration
statement filed with the Securities and Exchange Commission is
effective. This prospectus is not an offer to sell these
securities and we are not soliciting offers to buy these
securities in any state or other jurisdiction where the offer or
sale is not permitted.


Subject to completion, dated
    June 23, 2011
  Prospectus
  Shares
  
  COMMON STOCK
                  Per Share


TotalInitial public offering price

$



$Underwriting discounts and commissions

$



$Proceeds to Clovis, before expenses

$



$         Investing in our common stock involves risks. See
    Risk Factors beginning on page 10.
      Neither the Securities and Exchange Commission nor any state
    securities commission has approved or disapproved of these
    securities or determined if this prospectus is truthful or
    complete. Any representation to the contrary is a criminal
    offense.
        J.P.
    Morgan
    Credit Suisse  Leerink
    Swann




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##### 



TABLE OF
    CONTENTS
   
 PageProspectus Summary


1Risk Factors


10Cautionary Note Regarding Forward-Looking
    Statements and Industry Data


34Use of Proceeds


36Dividend Policy


36Capitalization


37Dilution


39Selected Consolidated Financial Data


41Managements Discussion and Analysis of
    Financial Condition and Results of Operations


43Business


56Management


88Executive and Director Compensation


95Certain Relationships and Related Party
    Transactions


102Principal Stockholders


105Description of Capital Stock


109Shares Eligible for Future Sale


112Material U.S. Federal Income and Estate Tax
    Considerations


115Underwriting


118Legal Matters


122Experts


122Where You Can Find More Information


122Index to Financial Statements


F-1EX-3.1EX-3.2EX-3.3EX-3.4EX-4.2EX-10.1EX-10.2EX-10.3EX-10.4EX-10.6EX-10.8EX-10.9EX-10.10EX-10.11EX-10.12EX-10.13EX-10.14EX-10.15EX-10.16EX-10.17EX-10.18EX-10.19EX-10.20EX-10.21EX-10.22EX-10.23EX-10.24EX-10.25EX-10.26EX-21.1EX-23.1      We have not, and the underwriters have not, authorized anyone
    to provide you with any information other than that contained in
    this prospectus or in any free writing prospectus we may
    authorize to be delivered or made available to you. We take no
    responsibility for, and can provide no assurance as to the
    reliability of, any other information that others may give you.
    This prospectus may only be used where it is legal to offer and
    sell shares of our common stock. The information in this
    prospectus is accurate only as of the date of this prospectus,
    regardless of the time of delivery of this prospectus or any
    sale of shares of our common stock.
     i




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PROSPECTUS
    SUMMARY  The following summary highlights information contained
    elsewhere in this prospectus and is qualified in its entirety by
    the more detailed information and consolidated financial
    statements included elsewhere in this prospectus. This summary
    does not contain all of the information that may be important to
    you. You should read and carefully consider the following
    summary together with the entire prospectus, including our
    consolidated financial statements and the related notes thereto
    appearing elsewhere in this prospectus and the matters discussed
    in the sections in this prospectus entitled Risk
    Factors, Selected Consolidated Financial Data
    and Managements Discussion and Analysis of Financial
    Condition and Results of Operations, before deciding to
    invest in our common stock. Some of the statements in this
    prospectus constitute forward-looking statements that involve
    risks and uncertainties. See Cautionary Note Regarding
    Forward-Looking Statements and Industry Data. Our actual
    results could differ materially from those anticipated in such
    forward-looking statements as a result of certain factors,
    including those discussed in the Risk Factors and
    other sections of this prospectus.
  Except as otherwise indicated herein or as the context
    otherwise requires, references in this prospectus to
    Clovis, the Company, we,
    us, and our, refer to Clovis Oncology, Inc.
    together with its consolidated subsidiary.
  Overview
  CO-101,
 1




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Our
    Strategy
    
    Focus on oncology.  The oncology market
    is characterized by a number of disorders with high rates of
    recurrence and a limited response from current therapies or
    treatments. Many of these therapies include severe side effects.
    New oncology product candidates addressing unmet medical needs
    or providing superior safety profiles are frequently the subject
    of expedited regulatory reviews and, if approved, can experience
    rapid adoption rates. We believe that the increasing role of
    targeted therapies and companion diagnostics to identify
    selected patient subsets in oncology presents the potential for
    improved patient outcomes.
    Focus on compounds where improved outcomes are associated
    with specific biomarkers.  Our licensing
    strategy to date has been to prioritize opportunities in which a
    strong biological hypothesis has been established linking a
    specific biomarker with improved outcomes for the product
    candidate. Significant progress has been made over the last
    several years in the identification of molecular targets and
    pathways that more narrowly specify the causes of cancer and the
    variation in responses to different therapies experienced by
    patient subsets with a particular cancer or tumor type. In
    certain cases, the underlying science has progressed to the
    point that subset patient populations deriving little or no
    benefit from existing therapies can be identified and targeted
    by newly developed therapies, such as our product candidates. We
    believe that the identification of such subsets, and the
    correlation of their specific characteristics to the drug under
    development, should increase the clinical benefit to targeted
    patients and the probability of success in our clinical trials.
    Such patient identification should also enable us to design
    clinical trials that may be completed more rapidly than has
    traditionally been the case, and, if successful, to achieve
    clinical outcomes for the targeted group that are sufficiently
    attractive to support the risk/benefit metrics of healthcare
    payors.
    Combine companion diagnostics with drug development
    efforts to realize superior clinical
    outcomes.  Our development strategy is based
    on the premise that we can utilize effective companion
    diagnostics to identify different patient subsets who we believe
    will uniquely benefit from our product candidates. We are
    partnering to develop these companion diagnostics for use in the
    clinical development and ultimate commercial utilization of our
    product candidates. Because we do not develop diagnostics
    internally, we are able to select from among all available
    technologies when choosing a partner for our programs under
    development. This flexibility allows us to choose the most
    appropriate partner and diagnostic platform for each program
    under development and affords us the best chance of clinical
    success. We have partnered with experienced diagnostic companies
    that we believe have the ability and commitment to gain the
    required regulatory approvals and support global
    commercialization for these companion diagnostics.
    Manage and control global development activities and
    regulatory operations.  We believe our
    development and regulatory experience enables us to devise time-
    and cost-efficient strategies to develop and obtain regulatory
    approvals for new drugs, and to identify the regulatory pathway
    that allows us to get a product candidate to market as quickly
    as possible. Unlike many early stage biotechnology and
    pharmaceutical companies that have development or regulatory
    capabilities only in the country in which they are located, we
    have assembled an experienced team with a successful track
    record at managing global clinical development activities, and
    with multinational expertise in obtaining regulatory approvals
    for new drugs and in maintaining compliance with the regulations
    governing the sales, marketing and distribution of
    pharmaceutical products. Because authorities in major markets
    are increasingly accepting one core dossier as the basis for
    regulatory approvals in multiple jurisdictions, we believe we
    can manage a global development program without local partners,
    thereby leveraging a single core dossier to gain approvals in
    multiple geographies. We manage critical functions in house,
    including clinical development, biostatistics, pharmaceutical
    development, molecular diagnostics and clinical and regulatory
    operations, and we outsource certain activities where
    economically and strategically appropriate.
    Seek and maintain global commercial
    rights.  We believe that it is very important
    to maintain global rights to our product candidates, and that we
    can build our own commercial organizations in major
 2




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pharmaceutical markets as well as a network of third-party
    distributors in smaller markets. There are a relatively small
    number of oncologists practicing in each of the major
    pharmaceutical markets and an even smaller number of oncology
    opinion leaders who significantly influence the types of drugs
    prescribed in cancer therapy. We therefore believe that we can
    effectively reach the oncology markets with a relatively small
    sales and marketing organization focused on these physicians and
    oncology opinion leaders. As a result, we plan to maintain
    commercial autonomy and will not require a pharmaceutical
    partner for commercialization activities. By managing the global
    sales and marketing of our products on our own, we believe we
    can provide uniform marketing programs and consistent product
    positioning, pricing and labeling. Finally, by controlling
    commercial activities ourselves in major markets, we will retain
    the vast majority of the revenues from our product candidates.  Our
    Product Pipeline
    
  CO-101 
    a Lipid-Conjugated Form of the Anti-Cancer Drug
    Gemcitabine
 3




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##### Table of Contents



CO-1686an
    Oral EGFR Mutant-Selective Inhibitor
    EGFR-mutated EGFR-mutated
  CO-338a
    PARP Inhibitor
  CO-338
  Risks
    Associated with Our Business
    
    We have incurred significant losses since our inception and
    anticipate that we will continue to incur losses for the
    foreseeable future. We are a clinical-stage company with no
    approved products, and no historical revenues, which makes it
    difficult to assess our future viability.
    If we fail to obtain additional financing, we may be unable to
    complete the development and commercialization of our product
    candidates, or continue our development programs. In addition,
    the report of our independent registered public accounting firm
    on our financial statements appearing at the end of this
    prospectus contains an explanatory paragraph stating that our
    recurring losses raise substantial doubt about our ability to
    continue as a going concern.
 4




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
    We are heavily dependent on the success of our three product
    candidates, two of which are in clinical development, and one of
    which is in preclinical development, and we cannot give any
    assurance that any of our product candidates will receive
    regulatory approval, which is necessary before they can be
    commercialized.
    Clinical drug development involves a lengthy and expensive
    process with an uncertain outcome, and results of earlier
    studies and trials may not be predictive of future trial results.
    The regulatory approval processes of the FDA and similar foreign
    authorities is lengthy, time consuming and inherently
    unpredictable, and if we are ultimately unable to obtain
    regulatory approval for our product candidates, our business
    will be substantially harmed.
    Failure to successfully validate, develop and obtain regulatory
    approval for companion diagnostics could harm our drug
    development strategy.
    Our commercial success depends upon attaining significant market
    acceptance of our product candidates, if approved, among
    physicians, patients, healthcare payors and major operators of
    cancer clinics.
    We face significant competition from other biotechnology and
    pharmaceutical companies and our operating results will suffer
    if we fail to compete effectively.
    If our efforts to protect the proprietary nature of the
    intellectual property related to our technologies are not
    adequate, we may not be able to compete effectively in our
    market.
    Other factors identified elsewhere in this prospectus, including
    those set forth under Risk Factors.  Our
    Corporate Information
  (303) 625-5000. www.clovisoncology.com.
 5




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THE
    OFFERING
  Common stock offered
    
    sharesCommon stock to be outstanding immediately following this
    offering
    
    sharesOver-allotment option
    
    Up
    to           sharesUse of proceeds
    
    We estimate that the net proceeds from this offering will be
    approximately $      million, or
    approximately $      million if
    the underwriters exercise their over-allotment option in full,
    assuming an initial public offering price of
    $      per share, the midpoint of the
    price range set forth on the cover page of this prospectus,
    after deducting estimated underwriting discounts and commissions
    and estimated offering expenses payable by us. We expect to use
    the proceeds of this offering to fund our clinical trials
    related to CO-101 and CO-338, to advance the development of
    CO-1686, our preclinical product candidate, and for working
    capital and general corporate purposes. See Use of
    Proceeds for a more complete description of the intended
    use of proceeds from this offering.Risk factors
    
    You should read Risk Factors for a discussion of
    factors you should carefully consider before deciding to invest
    in our common stock.Proposed NASDAQ Global Market symbol
    
    CLVS      
    2,746,779 shares of our common stock issuable upon the
    exercise of stock options outstanding as of March 31, 2011
    at a weighted-average exercise price of $0.91 per share;
    shares
    of our common stock reserved for future issuance under our 2011
    Equity Incentive Plan, or the 2011 Plan, which will become
    effective immediately prior to the completion of this offering,
    plus 1,248,621 shares of our common stock available for
    grant under our 2009 Equity Incentive Plan, or the 2009 Plan, as
    of March 31, 2011, which shares will be added to the shares
    to be reserved under our 2011 Plan upon the effectiveness of the
    2011 Plan, plus any annual increases in the number of shares of
    common stock reserved for future issuance under the 2011 Plan
    pursuant to an evergreen provision and any other
    shares that may become issuable under the 2011 Plan pursuant to
    its terms, as more fully described in Executive and
    Director CompensationEmployee Benefit Plans2011
    Equity Incentive Plan; and
    shares
    of our common stock reserved for future issuance under our 2011
    Employee Stock Purchase Plan, or the ESPP, which will become
    effective immediately prior to the completion of this offering,
    plus any annual increases in the number of shares of our common
    stock reserved for future issuance under the ESPP pursuant to an
    evergreen provision and any other shares that may
    become
 6




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issuable under the ESPP pursuant to its terms, as more fully
    described in Executive and Director
    CompensationEmployee Benefit Plans2011 Employee
    Stock Purchase Plan.    
    no exercise by the underwriters of their over-allotment option
    to purchase up
    to          
    additional shares of common stock from us;
    the consent of the requisite holders of our preferred stock for
    the conversion of their shares of preferred stock into common
    stock;
    the implementation of
    a          
    for          
    reverse stock split that we anticipate will occur prior to
    completion of this offering; and
    the filing of our amended and restated certificate of
    incorporation and the adoption of our amended and restated
    bylaws immediately prior to the completion of this offering.
 7




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SUMMARY
    CONSOLIDATED FINANCIAL DATA
        Period from








Cumulative fromApril 20, 2009








April 20, 2009Year Ended


(inception) to


Three Months Ended


(inception) toDecember 31,


December 31,


March 31,


March 31,2010


2009


2011


2010


2011(Unaudited)


(Unaudited)


(Unaudited)(In thousands, except per share amounts)Revenue

$



$



$



$



$
Operating expenses:Research and development


22,323



1,762



7,041



3,259



31,126General and administrative


4,302



2,209



1,405



830



7,916Acquired in-process research and development


12,000



13,085











25,085Operating loss


(38,625
)


(17,056
)


(8,446
)


(4,089
)


(64,127
)Other income (expense), net


795



(43
)


118



(2
)


870Net loss

$
(37,830
)

$
(17,099
)

$
(8,328
)

$
(4,091
)

$
(63,257
)Basic and diluted net loss per common
    share(1)

$
(9.85
)

$
(5.30
)

$
(2.15
)

$
(1.07
)

$
(17.45
)Basic and diluted weighted average common shares outstanding


3,842



3,225



3,877



3,832



3,625Pro forma basic and diluted net loss per common share
    (unaudited)(2)

$
(1.52
)





$
(0.33
)





$
(3.20
)Pro forma basic and diluted weighted average common shares
    outstanding (unaudited)


24,851







24,886







19,784   As of March 31, 2011Pro FormaActual


Pro
    Forma(2)


As
    Adjusted(3)(4)(Unaudited)


(Unaudited)(In thousands)Balance sheet data:Cash, cash equivalents and available for sale securities


$13,926


$



$Working capital


11,540Total assets


17,531Convertible preferred stock


75,499Total stockholders equity (deficit)


(63,023
)
 8




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##### Table of Contents



(1)
    
    See Note 11 within the notes to our financial statements
    for a description of the method used to compute basic and
    diluted loss per common share.(2)
    
    Pro forma to reflect (i) the issuance of $35.0 million
    in aggregate principal amount of our 5% convertible promissory
    notes due 2012; (ii) the conversion of all outstanding
    shares of our convertible preferred stock into
    21,009,196 shares of common stock immediately prior to the
    closing of this offering; and (iii) the conversion of
    $35.0 million in aggregate principal amount of our 5%
    convertible promissory notes due 2012 (including accrued and
    unpaid interest thereon)
    into           shares
    of our common stock immediately prior to the closing of this
    offering, assuming an initial public offering price of
    $          
    per share, the midpoint of the price range set forth on the
    cover page of this prospectus, and assuming the conversion
    occurs
    on          ,
    2011 (the expected closing date of this offering).(3)
    
    Pro forma as adjusted to further reflect the sale
    of           shares
    of our common stock offered in this offering, assuming an
    initial public offering price of
    $          
    per share, the midpoint of the price range set forth on the
    cover page of this prospectus, after deducting estimated
    underwriting discounts and commissions and estimated offering
    expenses payable by us.(4)
    
    A $1.00 increase or decrease in the assumed initial public
    offering price of
    $          
    per share, the midpoint of the price range set forth on the
    cover page of this prospectus, would increase or decrease the
    pro forma as adjusted amount of each of cash, cash equivalents
    and available for sale securities and each of working capital,
    total assets and total stockholders equity (deficit) by
    approximately
    $           million,
    assuming that the number of shares offered by us, as set forth
    on the cover page of this prospectus, remains the same, and
    after deducting estimated underwriting discounts and commissions
    and estimated offering expenses payable by us.
 9




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RISK
    FACTORS  Investing in our common stock involves a high degree of risk.
    You should carefully consider the risks described below,
    together with the other information contained in this
    prospectus, including our financial statements and the related
    notes appearing at the end of this prospectus, before making
    your decision to invest in shares of our common stock.
    Additional risks not presently known to us or that we currently
    deem immaterial may also impair our business operations. We
    cannot assure you that any of the events discussed in the risk
    factors below will not occur. These risks could have a material
    and adverse impact on our business, results of operations,
    financial condition and cash flows. If that were to happen, the
    trading price of our common stock could decline, and you could
    lose all or part of your investment.
  This prospectus also contains forward-looking statements that
    involve risks and uncertainties. Our actual results could differ
    materially from those anticipated in these forward-looking
    statements as a result of certain factors, including the risks
    faced by us described below and elsewhere in this prospectus.
    See Cautionary Note Regarding Forward-Looking Statements
    and Industry Data for information relating to these
    forward-looking statements.
  Risks
    Related to Our Financial Position and Capital
    Requirements
  We
    have incurred significant losses since our inception and
    anticipate that we will continue to incur losses for the
    foreseeable future. We are a clinical-stage company with no
    approved products, and no historical revenues, which makes it
    difficult to assess our future viability.
  CO-1686
  If we
    fail to obtain additional financing, we may be unable to
    complete the development and commercialization of our product
    candidates, or continue our development programs. In addition,
    the report of our independent registered public accounting firm
    on our financial statements appearing at the end of this
    prospectus contains an explanatory paragraph stating that our
    recurring losses raise substantial doubt about our ability to
    continue as a going concern.
   10




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Risks
    Related to Our Business and Industry
  We are
    heavily dependent on the success of our three product
    candidates, two of which are in clinical development, and one of
    which is in preclinical development, and we cannot give any
    assurance that any of our product candidates will receive
    regulatory approval, which is necessary before they can be
    commercialized.
  CO-1686,
  CO-101. third-party
   11




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##### Table of Contents



Clinical
    drug development involves a lengthy and expensive process with
    an uncertain outcome, and results of earlier studies and trials
    may not be predictive of future trial results.
      
    obtaining regulatory approval to commence a trial;
    reaching agreement on acceptable terms with prospective contract
    research organizations, or CROs, and clinical trial sites, the
    terms of which can be subject to extensive negotiation and may
    vary significantly among different CROs and trial sites;
    obtaining institutional review board, or IRB, approval at each
    site;
    recruiting suitable patients to participate in a trial;
    developing and validating companion diagnostics on a timely
    basis;
    having patients complete a trial or return for post-treatment
    follow-up;
    clinical sites deviating from trial protocol or dropping out of
    a trial;
    adding new clinical trial sites; or
    manufacturing sufficient quantities of product candidate for use
    in clinical trials.     12




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CO-338
  The
    regulatory approval processes of the FDA and comparable foreign
    authorities are lengthy, time consuming and inherently
    unpredictable, and if we are ultimately unable to obtain
    regulatory approval for our product candidates, our business
    will be substantially harmed.
      
    the FDA or comparable foreign regulatory authorities may
    disagree with the design or implementation of our clinical
    trials;
    we may be unable to demonstrate to the satisfaction of the FDA
    or comparable foreign regulatory authorities that a product
    candidate is safe and effective for its proposed indication;
    the results of clinical trials may not meet the level of
    statistical significance required by the FDA or comparable
    foreign regulatory authorities for approval;
    we may be unable to demonstrate that a product candidates
    clinical and other benefits outweigh its safety risks;
    the FDA or comparable foreign regulatory authorities may
    disagree with our interpretation of data from preclinical
    studies or clinical trials;
    the data collected from clinical trials of our product
    candidates may not be sufficient to support the submission of an
    NDA or other submission or to obtain regulatory approval in the
    United States or elsewhere;
    the FDA or comparable foreign regulatory authorities may fail to
    approve the manufacturing processes or facilities of third-party
    manufacturers with which we contract for clinical and commercial
    supplies;
    the FDA or comparable foreign regulatory authorities may fail to
    approve the companion diagnostics we contemplate developing with
    partners; and
    the approval policies or regulations of the FDA or comparable
    foreign regulatory authorities may significantly change in a
    manner rendering our clinical data insufficient for approval. 13




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Our
    product candidates may cause undesirable side effects or have
    other properties that could delay or prevent their regulatory
    approval, limit the commercial profile of an approved label, or
    result in significant negative consequences following marketing
    approval, if any.
      
    regulatory authorities may withdraw approvals of such product;
    regulatory authorities may require additional warnings on the
    label;
    we may be required to create a medication guide outlining the
    risks of such side effects for distribution to patients;
    we could be sued and held liable for harm caused to
    patients; and
    our reputation may suffer.    Failure
    to successfully validate, develop and obtain regulatory approval
    for companion diagnostics could harm our drug development
    strategy.
   14




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##### Table of Contents



and/or
  If we
    establish the hENT1 cut-off improperly, or if our LEAP trial
    results do not support the hENT1 hypothesis, we could jeopardize
    our potential for success with
    CO-101.
      If we
    are unable to obtain regulatory approval of our product
    candidates, we will not be able to commercialize them and our
    business will be adversely impacted.
   15




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We
    rely on third parties to conduct our preclinical and clinical
    trials. If these third parties do not successfully carry out
    their contractual duties or meet expected deadlines, we may not
    be able to obtain regulatory approval for or commercialize our
    product candidates and our business could be substantially
    harmed.
       16




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We
    rely completely on third parties to manufacture our preclinical
    and clinical drug supplies and we intend to rely on third
    parties to produce commercial supplies of any approved product
    candidate, and our commercialization of any of our product
    candidates could be stopped, delayed or made less profitable if
    those third parties fail to obtain approval of the FDA,
    Competent Authorities of the Member States of the EEA or
    comparable regulatory authorities, fail to provide us with
    sufficient quantities of drug product or fail to do so at
    acceptable quality levels or prices.
  and/or
     17




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Even
    if we receive regulatory approval for any of our product
    candidates, we will be subject to ongoing obligations and
    continued regulatory review, which may result in significant
    additional expense. Additionally, our product candidates, if
    approved, could be subject to labeling and other restrictions
    and market withdrawal and we may be subject to penalties if we
    fail to comply with regulatory requirements or experience
    unanticipated problems with our products.
    
    restrictions on the marketing or manufacturing of the product,
    withdrawal of the product from the market, or voluntary or
    mandatory product recalls;
    fines, warning letters or holds on clinical trials;
    refusal by the FDA to approve pending applications or
    supplements to approved applications filed by us, or suspension
    or revocation of product license approvals;
    product seizure or detention, or refusal to permit the import or
    export of products; and
    injunctions or the imposition of civil or criminal penalties.    We
    currently have no marketing and sales organization. If we are
    unable to establish marketing and sales capabilities or enter
    into agreements with third parties to market and sell our
    product candidates, we may not be able to effectively market and
    sell our product candidates, if approved, or generate product
    revenues.
   18




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##### Table of Contents



Our
    commercial success depends upon attaining significant market
    acceptance of our product candidates, if approved, among
    physicians, patients, healthcare payors and major operators of
    cancer clinics.
    
    the efficacy and safety as demonstrated in clinical trials;
    the timing of market introduction of such product candidate as
    well as competitive products;
    the clinical indications for which the drug is approved;
    the approval, availability, market acceptance and reimbursement
    for the companion diagnostic;
    acceptance by physicians, major operators of cancer clinics and
    patients of the drug as a safe and effective treatment;
    the potential and perceived advantages of such product candidate
    over alternative treatments, especially with respect to patient
    subsets that we are targeting with such product candidate;
    the safety of such product candidate seen in a broader patient
    group, including its use outside the approved indications;
    the cost of treatment in relation to alternative treatments;
    the availability of adequate reimbursement and pricing by
    third-party payors and government authorities;
    relative convenience and ease of administration;
    the prevalence and severity of adverse side effects; and
    the effectiveness of our sales and marketing efforts.    We
    face significant competition from other biotechnology and
    pharmaceutical companies, and our operating results will suffer
    if we fail to compete effectively.
     19




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##### Table of Contents



Reimbursement
    may be limited or unavailable in certain market segments for our
    product candidates, which could make it difficult for us to sell
    our products profitably.
      
    a covered benefit under its health plan;
    safe, effective and medically necessary;
    appropriate for the specific patient;
    cost-effective; and
    neither experimental nor investigational.      
    an annual, nondeductible fee on any entity that manufactures or
    imports certain branded prescription drugs and biologic agents,
    beginning in 2011;
    an increase in the minimum rebates a manufacturer must pay under
    the Medicaid Drug Rebate Program;
    a new Medicare Part D coverage gap discount program, under
    which manufacturers must agree to offer 50 percent
    point-of-sale
    discounts off negotiated prices of applicable brand drugs to
    eligible beneficiaries during their coverage gap period, as a
    condition for the manufacturers outpatient drugs to be
    covered under Medicare Part D, beginning in 2011;
    extension of manufacturers Medicaid rebate liability to
    covered drugs dispensed to individuals who are enrolled in
    Medicaid managed care organizations, effective March 23,
    2010; 20




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##### Table of Contents




    expansion of the entities eligible for discounts under the
    Public Health Service pharmaceutical pricing program, effective
    January 2010;
    a licensure framework for follow-on biologic products; and
    a new Patient-Centered Outcomes Research Institute to oversee,
    identify priorities in, and conduct comparative clinical
    effectiveness research.    
    the demand for any drug products for which we may obtain
    regulatory approval;
    our ability to set a price that we believe is fair for our
    products;
    our ability to generate revenues and achieve or maintain
    profitability;
    the level of taxes that we are required to pay; and
    the availability of capital.      If we
    are not successful in attracting and retaining highly qualified
    personnel, we may not be able to successfully implement our
    business strategy.
     21




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##### Table of Contents



We
    will need to grow the size of our organization, and we may
    experience difficulties in managing this growth.
    
    managing our clinical trials effectively;
    identifying, recruiting, maintaining, motivating and integrating
    additional employees;
    managing our internal development efforts effectively while
    complying with our contractual obligations to licensors,
    licensees, contractors and other third parties;
    improving our managerial, development, operational and finance
    systems; and
    expanding our facilities.    Our
    employees may engage in misconduct or other improper activities,
    including noncompliance with regulatory standards and
    requirements, which could have a material adverse effect on our
    business.
   22




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##### Table of Contents



We may
    be subject, directly or indirectly, to federal and state
    healthcare fraud and abuse laws, false claims laws and health
    information privacy and security laws. If we are unable to
    comply, or have not fully complied, with such laws, we could
    face substantial penalties.
    
    the federal Anti-Kickback Statute, which prohibits, among other
    things, persons from knowingly and willfully soliciting,
    receiving, offering or paying remuneration, directly or
    indirectly, to induce, or in return for, the purchase or
    recommendation of an item or service reimbursable under a
    federal healthcare program, such as the Medicare and Medicaid
    programs;
    federal civil and criminal false claims laws and civil monetary
    penalty laws, which prohibit, among other things, individuals or
    entities from knowingly presenting, or causing to be presented,
    claims for payment from Medicare, Medicaid, or other third-party
    payers that are false or fraudulent;
    the federal Health Insurance Portability and Accountability Act
    of 1996, or HIPAA, which created new federal criminal statutes
    that prohibit executing a scheme to defraud any healthcare
    benefit program and making false statements relating to
    healthcare matters;
    HIPAA, as amended by the Health Information Technology and
    Clinical Health Act, or HITECH, and its implementing
    regulations, which imposes certain requirements relating to the
    privacy, security and transmission of individually identifiable
    health information; and
    state law equivalents of each of the above federal laws, such as
    anti-kickback and false claims laws which may apply to items or
    services reimbursed by any third-party payer, including
    commercial insurers, and state laws governing the privacy and
    security of health information in certain circumstances, many of
    which differ from each other in significant ways and may not
    have the same effect, thus complicating compliance efforts.    If
    product liability lawsuits are brought against us, we may incur
    substantial liabilities and may be required to limit
    commercialization of our product candidates.
    
    decreased demand for our product candidates or products that we
    may develop;
    injury to our reputation;
    withdrawal of clinical trial participants;
    initiation of investigations by regulators; 23




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##### Table of Contents




    costs to defend the related litigation;
    a diversion of managements time and our resources;
    substantial monetary awards to trial participants or patients;
    product recalls, withdrawals or labeling, marketing or
    promotional restrictions;
    loss of revenues from product sales; and
    the inability to commercialize our product candidates.    Our
    ability to utilize our net operating loss carryforwards and
    certain other tax attributes may be limited.
    Our
    business and operations would suffer in the event of system
    failures.
    Risks
    Related to Our Intellectual Property
  If our
    efforts to protect the proprietary nature of the intellectual
    property related to our technologies are not adequate, we may
    not be able to compete effectively in our market.
   24




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Third-party
    claims of intellectual property infringement may prevent or
    delay our drug discovery and development efforts.
     25




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##### Table of Contents



CO-338
  The
    patent protection and patent prosecution for some of our product
    candidates is dependent on third parties.
    We may
    be involved in lawsuits to protect or enforce our patents or the
    patents of our licensors, which could be expensive, time
    consuming and unsuccessful.
       26




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We may
    not be able to protect our intellectual property rights
    throughout the world.
      If we
    breach any of the agreements under which we license
    commercialization rights to our product candidates from third
    parties, we could lose license rights that are important to our
    business.
    Intellectual
    property rights do not necessarily address all potential threats
    to our competitive advantage.
    
    Others may be able to make compounds that are similar to our
    product candidates but that are not covered by the claims of the
    patents that we own or have exclusively licensed.
    We or our licensors or strategic partners might not have been
    the first to make the inventions covered by the issued patent or
    pending patent application that we own or have exclusively
    licensed.
    We or our licensors or strategic partners might not have been
    the first to file patent applications covering certain of our
    inventions.
    Others may independently develop similar or alternative
    technologies or duplicate any of our technologies without
    infringing our intellectual property rights.
    It is possible that our pending patent applications will not
    lead to issued patents.
    Issued patents that we own or have exclusively licensed may not
    provide us with any competitive advantages, or may be held
    invalid or unenforceable, as a result of legal challenges by our
    competitors.
    Our competitors might conduct research and development
    activities in countries where we do not have patent rights and
    then use the information learned from such activities to develop
    competitive products for sale in our major commercial markets.
    We may not develop additional proprietary technologies that are
    patentable. 27




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
    The patents of others may have an adverse effect on our business.    Risks
    Related to This Offering and Ownership of our Common
    Stock
  We do
    not know whether an active, liquid and orderly trading market
    will develop for our common stock or what the market price of
    our common stock will be and as a result it may be difficult for
    you to sell your shares of our common stock.
    The
    price of our stock may be volatile, and you could lose all or
    part of your investment.
    
    our failure to commercialize our product candidates, if approved;
    actual or anticipated adverse results or delays in our clinical
    trials;
    unanticipated serious safety concerns related to the use of any
    of our product candidates;
    adverse regulatory decisions;
    changes in laws or regulations applicable to our product
    candidates, including but not limited to clinical trial
    requirements for approvals;
    disputes or other developments relating to proprietary rights,
    including patents, litigation matters and our ability to obtain
    patent protection for our product candidates;
    our decision to initiate a clinical trial, not to initiate a
    clinical trial or to terminate an existing clinical trial;
    our dependence on third parties, including CROs as well as our
    partners that provide us with companion diagnostic products;
    additions or departures of key scientific or management
    personnel;
    failure to meet or exceed any financial guidance or expectations
    regarding development milestones that we may provide to the
    public;
    actual or anticipated variations in quarterly operating results;
    failure to meet or exceed the estimates and projections of the
    investment community;
    overall performance of the equity markets and other factors that
    may be unrelated to our operating performance or the operating
    performance of our competitors, including changes in market
    valuations of similar companies;
    conditions or trends in the biotechnology and biopharmaceutical
    industries;
    introduction of new products offered by us or our competitors; 28




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
    announcements of significant acquisitions, strategic
    partnerships, joint ventures or capital commitments by us or our
    competitors;
    our ability to maintain an adequate rate of growth and manage
    such growth;
    issuances of debt or equity securities;
    significant lawsuits, including patent or stockholder litigation;
    sales of our common stock by us or our stockholders in the
    future;
    trading volume of our common stock;
    publication of research reports about us or our industry or
    positive or negative recommendations or withdrawal of research
    coverage by securities analysts;
    ineffectiveness of our internal controls;
    general political and economic conditions;
    effects of natural or man-made catastrophic events; and
    other events or factors, many of which are beyond our control.    Our
    principal stockholders and management own a significant
    percentage of our stock and will be able to exert significant
    control over matters subject to stockholder
    approval.
    If you
    purchase our common stock in this offering, you will incur
    immediate and substantial dilution in the book value of your
    shares.
   29




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We
    will incur increased costs as a result of operating as a public
    company, and our management will be required to devote
    substantial time to new compliance initiatives.
    Form 10-K
   30




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##### Table of Contents



Sales
    of a substantial number of shares of our common stock in the
    public market could cause our stock price to fall.
  lock-up lock-up lock-up
  lock-up lock-up lock-up
  lock-up
  Future
    sales and issuances of our common stock or rights to purchase
    common stock, including pursuant to our equity incentive plans,
    could result in additional dilution of the percentage ownership
    of our stockholders and could cause our stock price to
    fall.
     31




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##### Table of Contents



We
    have broad discretion in the use of the net proceeds from this
    offering and may not use them effectively.
    Some
    provisions of our charter documents and Delaware law may have
    anti-takeover effects that could discourage an acquisition of us
    by others, even if an acquisition would be beneficial to our
    stockholders and may prevent attempts by our stockholders to
    replace or remove our current management.
    
    authorizing the issuance of blank check preferred
    stock, the terms of which may be established and shares of which
    may be issued without stockholder approval;
    limiting the removal of directors by the stockholders;
    creating a staggered board of directors;
    prohibiting stockholder action by written consent, thereby
    requiring all stockholder actions to be taken at a meeting of
    our stockholders;
    eliminating the ability of stockholders to call a special
    meeting of stockholders;
    permitting our board of directors to accelerate the vesting of
    outstanding option grants upon certain transactions that result
    in a change of control; and
    establishing advance notice requirements for nominations for
    election to the board of directors or for proposing matters that
    can be acted upon at stockholder meetings.    If
    securities or industry analysts do not publish research or
    publish inaccurate or unfavorable research about our business,
    our stock price and trading volume could decline.
   32




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##### Table of Contents



Claims
    for indemnification by our directors and officers may reduce our
    available funds to satisfy successful third-party claims against
    us and may reduce the amount of money available to the
    Company.
      
    We will indemnify our directors and officers for serving us in
    those capacities or for serving other business enterprises at
    our request, to the fullest extent permitted by Delaware law.
    Delaware law provides that a corporation may indemnify such
    person if such person acted in good faith and in a manner such
    person reasonably believed to be in or not opposed to the best
    interests of the registrant and, with respect to any criminal
    proceeding, had no reasonable cause to believe such
    persons conduct was unlawful.
    We may, in our discretion, indemnify employees and agents in
    those circumstances where indemnification is permitted by
    applicable law.
    We are required to advance expenses, as incurred, to our
    directors and officers in connection with defending a
    proceeding, except that such directors or officers shall
    undertake to repay such advances if it is ultimately determined
    that such person is not entitled to indemnification.
    We will not be obligated pursuant to our bylaws to indemnify a
    person with respect to proceedings initiated by that person
    against us or our other indemnitees, except with respect to
    proceedings authorized by our board of directors or brought to
    enforce a right to indemnification.
    The rights conferred in our bylaws are not exclusive, and we are
    authorized to enter into indemnification agreements with our
    directors, officers, employees and agents and to obtain
    insurance to indemnify such persons.
    We may not retroactively amend our bylaw provisions to reduce
    our indemnification obligations to directors, officers,
    employees and agents. 33




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##### Table of Contents



CAUTIONARY
    NOTE REGARDING FORWARD-LOOKING STATEMENTS AND INDUSTRY
    DATA        
    the success and timing of our preclinical studies and clinical
    trials;
    our ability to obtain and maintain regulatory approval of our
    product candidates, and the labeling under any approval we may
    obtain;
    our plans to develop and commercialize our product candidates;
    our ability, with partners, to validate, develop and obtain
    regulatory approval of companion diagnostics for our product
    candidates;
    the loss of key scientific or management personnel;
    the size and growth of the potential markets for our product
    candidates and our ability to serve those markets;
    regulatory developments in the United States and foreign
    countries;
    the rate and degree of market acceptance of any of our product
    candidates;
    our use of the proceeds from this offering;
    the accuracy of our estimates regarding expenses, future
    revenues, capital requirements and needs for additional
    financing;
    our ability to obtain and maintain intellectual property
    protection for our product candidates;
    the successful development of our sales and marketing
    capabilities;
    the success of competing drugs that are or become
    available; and
    the performance of third-party manufacturers.   34




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35




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USE OF
    PROCEEDS             DIVIDEND
    POLICY   36




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##### Table of Contents



CAPITALIZATION    
    an actual basis;
    a pro forma basis giving effect to:  (1)
    the issuance of $35.0 million in aggregate principal amount
    of our 5% convertible promissory notes due 2012;(2)
    the conversion of all outstanding shares of our convertible
    preferred stock into 21,009,196 shares of common stock
    immediately prior to the closing of this offering; and(3)
    the conversion of $35.0 million in aggregate principal
    amount of our 5% convertible promissory notes due 2012
    (including accrued and unpaid interest thereon)
    into           shares
    of our common stock immediately prior to the closing of this
    offering, assuming an initial public offering price of
    $      per share, the midpoint of the
    price range set forth on the cover page of this prospectus, and
    assuming the conversion occurs
    on          ,
    2011 (the expected closing date of this offering); and  
    a pro forma as adjusted basis giving additional effect to the
    sale
    of           shares
    of our common stock offered in this offering, assuming an
    initial public offering price of $     
    per share, the midpoint of the price range set forth on the
    cover page of this prospectus, after deducting estimated
    underwriting discounts and commissions and estimated offering
    expenses payable by us.    As of March 31, 2011Pro FormaActual


Pro Forma


as
    Adjusted(1)(dollars in thousands)Cash and cash equivalents


$4,602


$



$5% convertible promissory notes due 2012


Convertible preferred stock, par value $0.001 per share;
    36,296,552 shares authorized; 21,009,196 shares issued
    and outstanding, actual; no shares authorized, issued or
    outstanding, pro forma and pro forma as adjusted


75,499Stockholders equity:Preferred stock, par value $0.001 per share; no shares
    authorized, issued or outstanding,
    actual;           shares
    authorized and no shares issued and outstanding, pro forma and
    pro forma as adjusted






Common stock, par value $0.001 per share; 55,000,000 shares
    authorized and 3,879,600 shares issued and outstanding,
    actual;           shares
    authorized
    and          shares
    issued and outstanding, pro forma
    and           shares
    issued and outstanding, pro forma as adjusted


4Additional paid-in capital


195Accumulated deficit


(63,257
)Accumulated other comprehensive income (loss)


35Total stockholders equity (deficit)


(63,023
)Total capitalization


$12,476


$



$  37




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##### Table of Contents



(1)
    
    A $1.00 increase (decrease) in the assumed initial public
    offering price of $      per share, the
    midpoint of the price range set forth on the cover page of this
    prospectus, would increase (decrease) the pro forma as adjusted
    amount of each of cash and cash equivalents, additional paid-in
    capital, total stockholders equity (deficit) and total
    capitalization by approximately
    $      million, assuming that the
    number of shares offered by us, as set forth on the cover page
    of this prospectus, remains the same and after deducting
    estimated underwriting discounts and commissions and estimated
    offering expenses payable by us.      
    2,746,779 shares of our common stock issuable upon the
    exercise of stock options outstanding as of March 31, 2011
    at a weighted-average exercise price of $0.91 per share;
    shares
    of our common stock reserved for future issuance under our 2011
    Equity Incentive Plan, or the 2011 Plan, which will become
    effective immediately prior to the completion of this offering,
    plus 1,248,621 shares of our common stock available for
    grant under our 2009 Equity Incentive Plan, or the 2009 Plan, as
    of March 31, 2011, which shares will be added to the shares
    to be reserved under our 2011 Plan upon the effectiveness of the
    2011 Plan, plus any annual increases in the number of shares of
    common stock reserved for future issuance under the 2011 Plan
    pursuant to an evergreen provision and any other
    shares that may become issuable under the 2011 Plan pursuant to
    its terms, as more fully described in Executive and
    Director CompensationEmployee Benefit Plans2011
    Equity Incentive Plan; and
    shares
    of our common stock reserved for future issuance under our 2011
    Employee Stock Purchase Plan, or the ESPP, which will become
    effective immediately prior to the completion of this offering,
    plus any annual increases in the number of shares of our common
    stock reserved for future issuance under the ESPP pursuant to an
    evergreen provision and any other shares that may
    become issuable under the ESPP pursuant to its terms, as more
    fully described in Executive and Director
    CompensationEmployee Benefit Plans2011 Employee
    Stock Purchase Plan. 38




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##### Table of Contents



DILUTION            Assumed initial public offering price per share





$Historical net tangible book deficit per share as of
    March 31, 2011 (unaudited)

$Pro forma increase in net tangible book value per share
    attributable to pro forma transactions described in preceding
    paragraphsPro forma net tangible book value per share as of March 31,
    2011 (unaudited)Pro forma increase in net tangible book value per share
    attributable to investors participating in this offeringPro forma as adjusted net tangible book value per share after
    this offeringDilution of pro forma as adjusted net tangible book value per
    share to new investors





$      39




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##### Table of Contents



Shares Purchased


Total Consideration


Average PriceNumber


Percent


Amount


Percent


per Share(dollars in thousands, except per share amounts)Existing stockholders before this offering









$







$Investors purchasing common stock in this offeringTotal









$







$     
    2,746,779 shares of our common stock issuable upon the
    exercise of stock options outstanding as of March 31, 2011
    at a weighted-average exercise price of $0.91 per share;
    shares
    of our common stock reserved for future issuance under our 2011
    Equity Incentive Plan, or the 2011 Plan, which will become
    effective immediately prior to the completion of this offering,
    plus 1,248,621 shares of our common stock available for
    grant under our 2009 Equity Incentive Plan, or the 2009 Plan, as
    of March 31, 2011, which shares will be added to the shares
    to be reserved under our 2011 Plan upon the effectiveness of the
    2011 Plan, plus any annual increases in the number of shares of
    common stock reserved for future issuance under the 2011 Plan
    pursuant to an evergreen provision and any other
    shares that may become issuable under the 2011 Plan pursuant to
    its terms, as more fully described in Executive and
    Director CompensationEmployee Benefit Plans2011
    Equity Incentive Plan; and
    shares
    of our common stock reserved for future issuance under our 2011
    Employee Stock Purchase Plan, or the ESPP, which will become
    effective immediately prior to the completion of this offering,
    plus any annual increases in the number of shares of our common
    stock reserved for future issuance under the ESPP pursuant to an
    evergreen provision and any other shares that may
    become issuable under the ESPP pursuant to its terms, as more
    fully described in Executive and Director
    CompensationEmployee Benefit Plans2011 Employee
    Stock Purchase Plan.       40




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##### Table of Contents



SELECTED
    CONSOLIDATED FINANCIAL DATA        Statement
    of Operations Data:
  Period from








Cumulative fromApril 20, 2009








April 20, 2009Year Ended


(Inception) to


Three Months Ended


(Inception) toDecember 31,


December 31,


March 31,


March 31,2010


2009


2011


2010


2011(unaudited)


(unaudited)


(unaudited)(in thousands, except per share amounts)Revenue

$



$



$



$



$
Operating expenses:Research and development


22,323



1,762



7,041



3,259



31,126General and administrative


4,302



2,209



1,405



830



7,916Acquired in-process research and development


12,000



13,085











25,085Operating loss


(38,625
)


(17,056
)


(8,446
)


(4,089
)


(64,127
)Other income (expense), net


795



(43
)


118



(2
)


870Net loss

$
(37,830
)

$
(17,099
)

$
(8,328
)

$
(4,091
)

$
(63,257
)Basic and diluted net loss per common share

$
(9.85
)

$
(5.30
)

$
(2.15
)

$
(1.07
)

$
(17.45
)Common shares used in the computation of basic and diluted net
    loss per common share


3,842



3,225



3,877



3,832



3,625Pro forma basic and diluted net loss per common share (unaudited)

$
(1.52
)





$
(0.33
)





$
(3.20
)Pro forma basic and diluted weighted average common shares
    outstanding (unaudited)


24,851







24,886







19,784  41




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##### Table of Contents



Balance
    Sheet Data:
  As of December 31,

As of March 31,2010

2009

2011(unaudited)(in thousands)Cash, cash equivalents and available for sale securities


$22,299



$57,311



$13,926Working capital


19,886



57,349



11,540Total assets


26,200



59,574



17,531Convertible preferred stock


75,499



75,499



75,499Total stockholders deficit


(54,749
)


(17,058
)


(63,023
)  42




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##### Table of Contents



MANAGEMENTS
    DISCUSSION AND ANALYSIS OF
    FINANCIAL CONDITION AND RESULTS OF OPERATIONS  You should read the following discussion and analysis of our
    financial condition and results of operations together with our
    financial statements and related notes appearing at the end of
    this prospectus. Some of the information contained in this
    discussion and analysis or set forth elsewhere in this
    prospectus, including information with respect to our plans and
    strategy for our business and related financing, includes
    forward-looking statements that involve risks and uncertainties.
    You should read the Risk Factors section of this
    prospectus for a discussion of important factors that could
    cause actual results to differ materially from the results
    described in or implied by the forward-looking statements
    contained in the following discussion and analysis.
  Overview
  CO-101,
       43




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Convertible
    Promissory Notes
    
    In May 2011, we issued $20.0 million aggregate principal
    amount of 5% convertible promissory notes due 2012 to raise
    additional working capital to advance the development programs
    of our product candidates and for general corporate purposes.
    The notes accrue interest at an annual rate of 5% and mature on
    May 25, 2012. Upon the completion of this offering, the
    principal balance and all accrued and unpaid interest due on the
    notes will be converted into shares of our common stock at a per
    share price equal to the initial public offering price shown on
    the cover page of this prospectus.
    In June 2011, we entered into a license agreement with Pfizer as
    further described under the heading Product License
    Agreements. Pursuant to the terms of the license
    agreement, we made an up-front payment by issuing Pfizer
    $7.0 million principal amount of a 5% convertible
    promissory note due 2012. Pfizer concurrently purchased for cash
    an additional $8.0 million principal amount of another 5%
    convertible promissory note due 2012, bringing the total
    principal amount of the notes issued to Pfizer to
    $15.0 million. These convertible notes have substantially
    the same terms as the $20.0 million aggregate principal
    amount of convertible promissory notes described in the
    preceding paragraph, including identical interest provisions,
    maturity date, and conversion features.  Product
    License Agreements
  CO-101
      CO-1686
  CO-1686.
 44




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##### Table of Contents



CO-338
    Financial
    Operations Overview
  Revenue
    Research
    and Development Expenses
    
    license fees related to the acquisition of in-licensed products,
    which are reported on our statements of operations as acquired
    in-process research and development;
    employee-related expenses, including salaries, benefits, travel
    and stock-based compensation expense;
    expenses incurred under agreements with CROs and investigative
    sites that conduct our clinical trials and preclinical studies;
    the cost of acquiring, developing and manufacturing clinical
    trial materials;
    costs associated with preclinical activities and regulatory
    operations; and
    activities associated with the development of companion
    diagnostics for our product candidates.     45




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##### Table of Contents



Period fromApril 20, 2009





Cumulative fromYear Ended


(Inception) to


Three Months Ended


April 20, 2009December 31,


December 31,


March 31,


(Inception) to2010


2009


2011


2010


March 31, 2011(unaudited, in thousands)(in thousands)CO-101 ExpensesAcquired in-process R&D

$
10,000


$
13,085


$



$



$
23,085Research and development


14,461



371



3,762



2,387



18,594CO-101 Total


24,461



13,456



3,762



2,387



41,679CO-1686 ExpensesAcquired in-process R&D


2,000















2,000Research and development


2,432







1,289







3,721CO-1686 Total


4,432







1,289







5,721Personnel and other expenses


5,430



1,391



1,990



872



8,811Total

$
34,323


$
14,847


$
7,041


$
3,259


$
56,211   General
    and Administrative Expenses
      
    increased personnel expenses to support the growth in research
    and development activities; and
    increased expenses related to becoming a publicly traded
    company, including increased legal and accounting services,
    addition of new headcount to support compliance and
    communication needs, and increased insurance premiums.  Other
    Income and Expense
   46




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##### Table of Contents



Critical
    Accounting Policies and Significant Judgments and
    Estimates
      Accrued
    Research and Development Expenses
    
    fees paid to CROs in connection with clinical studies;
    fees paid to investigative sites in connection with clinical
    studies;
    fees paid to vendors in connection with preclinical development
    activities;
    fees paid to vendors associated with the development of
    companion diagnostics; and
    fees paid to vendors related to product manufacturing,
    development and distribution of clinical supplies.    Stock-Based
    Compensation
   47




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##### Table of Contents



Period from April 20



Three MonthsYear Ended



(Inception) Through



EndedDecember 31,



December 31,



March 31,2010



2009



2011(unaudited)Dividend yield












Volatility


80

%


80

%


74

%Risk-free interest rate


2.10

%


2.33

%


2.48

%Expected term (years)


5.61




5.30




6.00        48




---



##### Table of Contents



Number ofShares



Common StockUnderlying

Exercise

Fair Value perOptions

Price per

Share on GrantPeriod of Grant

Granted

Share

DateApril 20, 2009 (inception) to June 30, 2009





$



$
July 1, 2009 to September 30, 2009


755,000


$
0.10


$
0.10October 1, 2009 to December 31, 2009


147,500


$
0.10


$
0.10January 1, 2010 to March 31, 2010










April 1, 2010 to June 30, 2010


451,500


$
1.06


$
1.06July 1, 2010 to September 30, 2010


3,000


$
1.06


$
1.06October 1, 2010 to December 31, 2010


245,000


$
1.06


$
1.06January 1, 2011 to March 31, 2011


1,549,900


$
1.13


$
1.13       Series A-2
  Valuation
    of Privately-Held-Company Equity Securities Issued as
    Compensation,
    
    Underlying equity value  To estimate the value of our
    total equity (including both common and preferred equity), we
    utilized the marketable equity value based on the most recent
    rounds our preferred stock issuances, which we believed to be
    the most indicative of our value.
    Volatility  We estimated volatility based on
    comparison to volatility of publicly-traded comparable companies.
    Time to liquidity  We estimated time to a liquidity
    event based on the forecasted time to significant clinical
    development events for our product candidates which we believed
    could lead to an initial public offering, or IPO, or other type
    of liquidation event for our stockholders.
    Risk-free interest rate  We determined the risk-free
    interest rate based on the yield of a U.S. Treasury bill
    with a maturity date closest to the estimated time to a
    liquidation event for our stockholders. 49




---



##### Table of Contents




    Discounts for lack of marketability  Because we are a
    privately-held company, shares of our common stock are highly
    illiquid and, as such, warrant a discount in value from their
    estimated marketable price. We estimate the discount
    factor for illiquidity using legal guidelines from U.S. Tax
    Court cases regarding privately-held business valuations,
    fundamental business factors, and empirical studies on the
    discount for lack of marketability. We corroborated the discount
    factor based on the value of a put option compared to the value
    of common stock using a Black-Scholes option pricing model.        Results
    of Operations
  Comparison
    of the Three Months Ended March 31, 2011 and
    2010:
  Three Months EndedMarch 31,


Increase2011


2010


(Decrease)(unaudited, in thousands)Revenues

$



$



$
Expenses:Research and development


7,041



3,259



3,782General and administrative


1,405



830



575Operating loss


(8,446
)


(4,089
)


4,357Other income (expense), net


118



(2
)


120Net loss

$
(8,328
)

$
(4,091
)

$
4,237   Research and Development
    Expenses.
 50




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##### Table of Contents



General and Administrative
    Expenses.
  Other Income (Expense), Net.
  Comparison
    of the Year Ended December 31, 2010 to the Period from
    April 20, 2009 (Inception) to December 31,
    2009:
  Period fromApril 20, 2009Year ended


(Inception) toDecember 31,


December 31,


Increase2010


2009


(Decrease)Revenues

$



$



$
Expenses:Research and development


22,323



1,762



20,561General and administrative


4,302



2,209



2,093Acquired in-process research and development


12,000



13,085



(1,085
)Operating loss


(38,625
)


(17,056
)


21,569Other income (expense), net


795



(43
)


838Net loss

$
(37,830
)

$
(17,099
)

$
20,731   Research and Development
    Expenses.
  
    increase of $5.5 million related to the commencement of our
    pivotal clinical trial for CO-101 in January 2010;
    increase of $4.7 million for CO-101 drug product
    development, clinical supply manufacturing and distribution;
    increase of $2.3 million associated with CO-1686 product
    development and IND enabling activities;
    increase of $2.0 million for the initiation of additional
    supporting CO-101 clinical studies;
    increase of $1.1 million for companion diagnostic
    development related to both CO-101 and
    CO-1686; and
    increase of $4.0 million to salaries, benefits and other
    personnel costs to support the growth in our 2010 development
    activities.  General and Administrative
    Expenses.
 51




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##### Table of Contents



Acquired In-Process Research and Development
    Expenses.
  Other Income (Expense), Net.
  Liquidity
    and Capital Resources
      Period fromApril 20, 2009Year Ended


(Inception) to


Three Months EndedDecember 31,


December 31,


March 31,2010


2009


2011


2010(unaudited)


(unaudited)Net cash used in operating activities

$
(34,011
)

$
(17,955
)

$
(8,188
)

$
(4,911
)Net cash provided by (used in) investing activities


(12,821
)


(270
)


2,280



(20,306
)Net cash provided by financing activities


29



75,536



2



Net increase (decrease) in cash and cash equivalents

$
(46,803
)

$
57,311


$
(5,906
)

$
(25,217
)   Operating
    Activities
   52




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##### Table of Contents



Investing
    Activities
    Financing
    Activities
  Series A-1 Series A-2
  Operating
    Capital Requirements
         53




---



##### Table of Contents




    the number and characteristics of the product candidates,
    companion diagnostics, and indications we pursue;
    the achievement of various development, regulatory and
    commercial milestones resulting in required payments to partners
    pursuant to the terms of our license agreements;
    the scope, progress, results and costs of researching and
    developing our product candidates and related companion
    diagnostics and conducting clinical and preclinical trials;
    the timing of, and the costs involved in, obtaining regulatory
    approvals for our product candidates and companion diagnostics;
    the cost of commercialization activities, if any, of our product
    candidates are approved for sale, including marketing and
    distribution costs;
    the cost of manufacturing any of our product candidates we
    successfully commercialize;
    the costs involved in preparing, filing, prosecuting,
    maintaining, defending and enforcing patent claims, including
    litigation costs and outcome of such litigation; and
    the timing, receipt and amount of sales, if any, of our product
    candidates.  Contractual
    Obligations and Commitments
    Less than





More thanTotal

1 Year

1 to 3 Years

3 to 5 Years

5 YearsOperating lease obligations

$
2,198


$
665


$
1,140


$
393



   CO-101,
   54




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##### Table of Contents



Off-Balance
    Sheet Arrangements
    Tax Loss
    Carryforwards
    Quantitative
    and Qualitative Disclosures about Market Risks
        Recently
    Adopted Accounting Standards
    Financial
    Statements and Supplementary Data
  page F-1
 55




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##### Table of Contents



BUSINESS  Overview
  CO-101,
        
    CO-101-Our most advanced product candidate, CO-101, is
    currently in a pivotal clinical study comparing CO-101 to
    gemcitabine for first-line treatment of metastatic pancreatic
    cancer. We expect to complete enrollment for this trial in the
    first quarter of 2012 and report top line results as to overall
    survival in the prespecified hENT1-low patient subset in the
    fourth quarter of 2012. CO-101 is a novel, patented,
    lipid-conjugated form of the anti-cancer drug gemcitabine that
    is designed to treat patients with pancreatic cancer whose
    tumors express low amounts of a membrane transporter protein on
    the surface of the cancer cell known as hENT1 and are thus
    expected to be resistant to standard gemcitabine-based therapy.
    Based on the published results of multiple studies assessing the
    correlation of hENT1 expression to survival outcomes in
    pancreatic cancer patients treated with gemcitabine, we estimate
    that approximately 40% to 50% of pancreatic patients express low
    levels of hENT1, and thus derive little or no benefit from
    gemcitabine therapy. We have partnered with Ventana Medical
    Systems for the development and commercialization of a companion
    diagnostic for the assessment of hENT1 levels.
    CO-1686-Our second product candidate, CO-1686, is an
    orally available, small molecule covalent inhibitor of the
    cancer-causing mutant forms of EGFR for the treatment of NSCLC.
    Because CO-1686 targets both the initial activating mutations as
    well as the primary resistance mutation, T790M, it has the
    potential to treat both first- and second-line NSCLC patients
    with EGFR mutations. CO-1686 is currently in preclinical
    development and we plan to file an Investigational New Drug
    application, or IND, in the first quarter of 2012. We have
    designed an accelerated clinical development program for
    CO-1686, and if successful, have a goal of filing a New Drug
    Application, or NDA, for an initial indication within 56




---



##### Table of Contents



approximately four years of filing our IND. We have partnered
    with Roche Molecular Systems for the development and
    commercialization of a companion diagnostic for EGFR mutations.  
    CO-338-Our third product candidate, CO-338, is an orally
    available, small molecule PARP inhibitor being developed for use
    as monotherapy or in combination with chemotherapeutic agents
    for the treatment of various cancers. CO-338 is currently in a
    dose ranging Phase I clinical trial in combination with
    carboplatin chemotherapy for the treatment of solid tumors. This
    program is supplemented by two investigator-sponsored trials of
    CO-338 for the treatment of breast and ovarian cancers. We
    intend to initiate a Phase I monotherapy study of the oral
    formulation in the fourth quarter of 2011 to determine an
    appropriate dose and schedule for long term administration.    Our
    Strategy
    
    Focus on oncology.  The oncology market
    is characterized by a number of disorders with high rates of
    recurrence and a limited response from current therapies or
    treatments. Many of these therapies include severe side effects.
    New oncology product candidates addressing unmet medical needs
    or providing superior safety profiles are frequently the subject
    of expedited regulatory reviews and, if approved, can experience
    rapid adoption rates. We believe that the increasing role of
    targeted therapies and companion diagnostics to identify
    selected patient subsets in oncology presents the potential for
    improved patient outcomes.
    Focus on compounds where improved outcomes are associated
    with specific biomarkers.  Our licensing
    strategy to date has been to prioritize opportunities in which a
    strong biological hypothesis has been established linking a
    specific biomarker with improved outcomes for the product
    candidate. Significant progress has been made over the last
    several years in the identification of molecular targets and
    pathways that more narrowly specify the causes of cancer and the
    variation in responses to different therapies experienced by
    patient subsets with a particular cancer or tumor type. In
    certain cases, the underlying science has progressed to the
    point that subset patient populations deriving little or no
    benefit from existing therapies can be identified and targeted
    by newly developed therapies, such as our product candidates. We
    believe that the identification of such subsets, and the
    correlation of their specific characteristics to the drug under
    development, should increase the clinical benefit to targeted
    patients and the probability of success in our clinical trials.
    Such patient identification should also enable us to design
    clinical trials that may be completed more rapidly than has
    traditionally been the case, and, if successful, to achieve
    clinical outcomes for the targeted group that are sufficiently
    attractive to support the risk/benefit metrics of healthcare
    payors.
    Combine companion diagnostics with drug development
    efforts to realize superior clinical
    outcomes.  Our development strategy is based
    on the premise that we can utilize effective companion
    diagnostics to identify different patient subsets who we believe
    will uniquely benefit from our product candidates. We are
    partnering to develop these companion diagnostics for use in the
    clinical development and ultimate commercial utilization of our
    product candidates. Because we do not develop diagnostics
    internally, we are able to select from among all available
    technologies when choosing a partner for our programs under
    development. This flexibility allows us to choose the most
    appropriate partner and diagnostic platform for each program
    under development and affords us the best chance of clinical
    success. We have partnered with experienced diagnostic companies
    that we believe have the ability and commitment to gain the
    required regulatory approvals and support global
    commercialization for these companion diagnostics. 57




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##### Table of Contents




    Manage and control global development activities and
    regulatory operations.  We believe our
    development and regulatory experience enables us to devise time-
    and cost-efficient strategies to develop and obtain regulatory
    approvals for new drugs, and to identify the regulatory pathway
    that allows us to get a product candidate to market as quickly
    as possible. Unlike many early stage biotechnology and
    pharmaceutical companies that have development or regulatory
    capabilities only in the country in which they are located, we
    have assembled an experienced team with a successful track
    record at managing global clinical development activities, and
    with multinational expertise in obtaining regulatory approvals
    for new drugs and in maintaining compliance with the regulations
    governing the sales, marketing and distribution of
    pharmaceutical products. Because authorities in major markets
    are increasingly accepting one core dossier as the basis for
    regulatory approvals in multiple jurisdictions, we believe we
    can manage a global development program without local partners,
    thereby leveraging a single core dossier to gain approvals in
    multiple geographies. We manage critical functions in house,
    including clinical development, biostatistics, pharmaceutical
    development, molecular diagnostics and clinical and regulatory
    operations, and we outsource certain activities where
    economically and strategically appropriate.
    Seek and maintain global commercial
    rights.  We believe that it is very important
    to maintain global rights to our product candidates, and that we
    can build our own commercial organizations in major
    pharmaceutical markets as well as a network of third-party
    distributors in smaller markets. There are a relatively small
    number of oncologists practicing in each of the major
    pharmaceutical markets and an even smaller number of oncology
    opinion leaders who significantly influence the types of drugs
    prescribed in cancer therapy. We therefore believe that we can
    effectively reach the oncology markets with a relatively small
    sales and marketing organization focused on these physicians and
    oncology opinion leaders. As a result, we plan to maintain
    commercial autonomy and will not require a pharmaceutical
    partner for commercialization activities. By managing the global
    sales and marketing of our products on our own, we believe we
    can provide uniform marketing programs and consistent product
    positioning, pricing and labeling. Finally, by controlling
    commercial activities ourselves in major markets, we will retain
    the vast majority of the revenues from our product candidates.  Product
    Candidates
    
 58




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##### Table of Contents



CO-101 - a
    Lipid-Conjugated form of the Anti-Cancer Drug
    Gemcitabine
  Overview
    Pancreatic
    Cancer Market Overview
    ® tm (5-FU),
  Targeting
    Gemcitabine Non-Responders: the hENT1 Hypothesis
  Clinical Cancer Research
 59




---



##### Table of Contents



Kaplan-Meier estimate of survival in gemcitabine-treated
    hENT1-high and hENT1-low pancreatic cancer patients.
  
  *hENT1-high
   Gastroenterology
  
 60




---



##### Table of Contents



A positive, and statistically significant association is seen
    between tumor hENT1 expression and overall survival for
    recipients of gemcitabine (left, p=0.002 for high vs. no hENT1,
    p=0.03 for low vs. no hENT1), but not for recipients of
    5-FU (right,
    p=not significant). hENT1 expression was characterized as no,
    low or high. High hENT1 was defined by strong
    reactivity in greater than 50% of neoplastic cells on IHC,
    whereas no hENT1 was defined as no staining in
    greater than 50% of neoplastic cells. A score of low hENT1
    staining was given to all cases in between.
    
  CO-101:
    Addressing Patients with Low Levels of hENT1
  in vitro in
    vivo in vivo
  CO-101
    Clinical Development
  LEAP Study: Pivotal Trial of CO-101 in First-Line Pancreatic
    Cancer. L E A P one-to-one CO-101 2 2
 61




---



##### Table of Contents



in vitro
  
    Ability to analyze accessible tissue: Patients with
    metastatic pancreatic cancer typically have liver metastases
    which can be biopsied quite easily and analyzed by IHC;
    Simple assay/local analysis: IHC is a standard
    laboratory technique that is widely utilized and does not
    require samples to be sent off-site for analysis;  
    Based on existing technology: Ventana utilized
    established IHC diagnostic techniques to develop a validated
    hENT1 IHC assay using knowledge already gained from IHC hENT1
    assays developed by academics;  
    Regulatory precedent: IHC IVDs have previously been
    approved by the FDA as companion diagnostics for cancer
    therapeutics, including Ventanas PATHWAY HER-2/neu assay
    intended to assist in the assessment of breast cancer patients
    for whom Herceptin treatment is considered; and
    Reimbursement: IHC diagnostic kits are widely
    reimbursed by health care payors.    Study CO-101-002: Establishing a hENT1
    Cut-Off. hENT1-low.
 62




---



##### Table of Contents



Study CO-101-003: a Phase II Study in Second-Line
    Pancreatic Cancer.
  follow-up
  Study CO-101-004: a Study Conducted for Formulation
    Development. CO-101-004
 63




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##### Table of Contents



Other Potential Indications for CO-101: the hENT1 Hypothesis
    Applied to other Cancers.
  Early
    Clinical Development of CO-101
    Study
    CP-4126-201:
    an Abbreviated Phase II Study Conducted by Clavis
    Pharma. CO-101 CO-101 1250 mg/m 2 19-9, CO-101
  19-9 CO-101 hENT1-low
  and/or CO-101 patients
  Phase I Trial: First in Man Study on
    CP-4126. first-in-human
 64




---



##### Table of Contents



2 1000mg/m 2 2
  Regulatory
    strategy
  CO-101 LEAP Trial Design and Requirements for Regulatory
    Approval.
  CO-101
                   65




---



##### Table of Contents



in vitro
  CO-1686 - an
    Oral EGFR Mutant-Selective Inhibitor
  Overview
  tm tm
  Market
    Overview: Resistance to EGFR Tyrosine Kinase Inhibitors, or
    TKIs, Represents an Unmet Medical Need
  Lung Cancer and EGFR TKIs.
  ® ®
 66




---



##### Table of Contents



tm tm
  and/or
    Resistance to EGFR TKIs.
   67




---



##### Table of Contents



Opportunity
    for Clovis
    
    potential to effectively treat patients with T790M mutant EGFR
    NSCLCa large and growing group of patients, which have
    been identified with greater frequency due to recently approved
    guidelines, who today have no effective therapy;
    potential to effectively treat patients with initial activating
    mutations in the EGFR who receive first-generation
    TKIs, but develop resistance due to the acquired T790M mutation;
    CO-1686 would be expected to prevent resistance through this
    mechanism and may thus cause responses of greater duration than
    seen with first generation TKIs and extend progression-free
    survival; and
    it would not be expected to inhibit normal EGFR in skin or
    intestine, and thus would be less likely to cause skin rash and
    diarrhea, which are dose limiting with all other EGFR inhibitors.  Design of
    CO-1686  a Targeted Covalent Drug
    ® ® tm
          Preclinical
    Development
  in vitro
 68




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##### Table of Contents



tm CO-1686
    Clinical
    Development
  I/II
  benefit-to-risk CO-1686.
  CO-338 - a
    PARP Inhibitor
  Overview
    CO-338
 69




---



##### Table of Contents



DNA
    Repair and PARP
        Synthetic
    Lethality
  in vitro
   70




---



##### Table of Contents



PARP
    Inhibitor Development Strategy
    
    monotherapy in germ-line BRCA patients (mostly breast and
    ovarian cancer although a few patients develop tumors in
    pancreas and prostate);
    monotherapy (induction
    and/or
    maintenance therapy) in patients with high BRCA-ness tumors; and
    combination therapy with cytotoxic chemotherapy or radiation or
    targeted therapy in other tumors.    Opportunity
    for Clovis
    
    it is a very potent inhibitor of PARP-1 and PARP-2 proteins;
    it is available in both oral and IV. In combination with
    intravenous cytotoxic chemotherapy, it is possible that brief,
    high-intensity PARP inhibition is optimal for efficacy, and an
    intravenous formulation may be a preferred option under such
    conditions;
    the oral formulation offers good bioavailability and low
    inter-individual pharmacokinetic variability;
    CO-338 can be used as monotherapy in germ-line BRCA patients and
    has shown activity in this setting (with the IV
    formulation);
    CO-338 can be used in combination with cytotoxic chemotherapy
    and can be safely given at doses shown to be highly PARP
    inhibitory, as suggested by the trial results described below;
    and
    CO-338 can likely be used as oral maintenance therapy after
    cytotoxic chemotherapy.  Clinical
    Development of CO-338
  IV Formulation. 2 2
   71




---



##### Table of Contents



2 2
  Oral Formulation.
      and/or
  Competition
        CO-101
    Competition
  ® tm
 72




---



##### Table of Contents



CO-1686
    Competition
    CO-338
    Competition
  E-7016 BMN-673
  Collaborators
    and License Agreements
  Clavis
    Pharma ASA
     73




---



##### Table of Contents



Avila
    Therapeutics, Inc.
    sub-licensing
  product-by-product country-by-country
  Pfizer,
    Inc.
   74




---



##### Table of Contents



CO-338,
  product-by-product country-by-country CO-338
  Government
    Regulation
    U.S.
    Government Regulation
    
    submission to the FDA of an IND which must become effective
    before human clinical trials may begin and must be updated
    annually;
    completion of extensive preclinical laboratory tests and
    preclinical animal studies, all performed in accordance with the
    FDAs Good Laboratory Practice, or GLP, regulations;
    performance of adequate and well-controlled human clinical
    trials to establish the safety and efficacy of the product
    candidate for each proposed indication;
    submission to the FDA of an NDA after completion of all pivotal
    clinical trials;
    a determination by the FDA within 60 days of its receipt of
    an NDA to file the NDA for review;
    satisfactory completion of an FDA pre-approval inspection of the
    manufacturing facilities at which the active pharmaceutical
    ingredient, or API, and finished drug product are produced and
    tested to assess compliance with cGMP regulations; and
    FDA review and approval of an NDA prior to any commercial
    marketing or sale of the drug in the United States. 75




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##### Table of Contents




    Phase I.  Phase I includes the initial
    introduction of an investigational new drug into humans. Phase I
    clinical trials are typically closely monitored and may be
    conducted in patients with the target disease or condition or in
    healthy volunteers. These studies are designed to evaluate the
    safety, dosage tolerance, metabolism and pharmacologic actions
    of the investigational drug in humans, the side effects
    associated with increasing doses, and if possible, to gain early
    evidence on effectiveness. During Phase I clinical trials,
    sufficient information about the investigational drugs
    pharmacokinetics and pharmacological effects may be obtained to
    permit the design of well-controlled and scientifically valid
    Phase II clinical trials. The total number of participants
    included in Phase I clinical trials varies, but is generally in
    the range of 20 to 80.
    Phase II.  Phase II includes controlled
    clinical trials conducted to preliminarily or further evaluate
    the effectiveness of the investigational drug for a particular
    indication(s) in patients with the disease or condition under
    study, to determine dosage tolerance and optimal dosage, and to
    identify possible adverse side effects and safety risks
    associated with the drug. Phase II clinical trials are
    typically well-controlled, closely monitored, and conducted in a
    limited patient population, usually involving no more than
    several hundred participants.
    Phase III.  Phase III clinical trials are
    generally controlled clinical trials conducted in an expanded
    patient population generally at geographically dispersed
    clinical trial sites. They are performed after preliminary
    evidence suggesting effectiveness of the drug has been obtained,
    and are intended to further evaluate dosage, clinical
    effectiveness and safety, to establish the overall benefit-risk
    relationship of the investigational drug product, and to provide
    an adequate basis for product approval. Phase III clinical
    trials usually involve several hundred to several thousand
    participants.  and/or
 76




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and/or and/or and/or
     77




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Europe/Rest
    of World Government Regulation
              Available
    Special Regulatory Procedures
  Formal
    Meetings
       78




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Orphan
    Drug Designation
          Pediatric
    Development
  end-of-Phase II
  and/or
  Authorization
    Procedures in the European Union
    
    Centralized procedure.  The EMA implemented the
    centralized procedure for the approval of human medicines to
    facilitate marketing authorizations that are valid throughout
    the European Union. This 79




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procedure results in a single marketing authorization issued by
    the EMA that is valid across the European Union, as well as
    Iceland, Liechtenstein and Norway. The centralized procedure is
    compulsory for human medicines that are: derived from
    biotechnology processes, such as genetic engineering, contain a
    new active substance indicated for the treatment of certain
    diseases, such as HIV/AIDS, cancer, diabetes, neurodegenerative
    disorders or autoimmune diseases and other immune dysfunctions,
    and officially designated orphan medicines.  
    For medicines that do not fall within these categories, an
    applicant has the option of submitting an application for a
    centralized marketing authorization to the EMA, as long as the
    medicine concerned is a significant therapeutic, scientific or
    technical innovation, or if its authorization would be in the
    interest of public health.
    National authorization procedures.  There are
    also two other possible routes to authorize medicinal products
    in several countries, which are available for investigational
    drug products that fall outside the scope of the centralized
    procedure:  
    Decentralized procedure.  Using the
    decentralized procedure, an applicant may apply for simultaneous
    authorization in more than one European Union country of
    medicinal products that have not yet been authorized in any
    European Union country and that do not fall within the mandatory
    scope of the centralized procedure.
    Mutual recognition procedure.  In the mutual
    recognition procedure, a medicine is first authorized in one
    European Union Member State, in accordance with the national
    procedures of that country. Following this, further marketing
    authorizations can be sought from other European Union countries
    in a procedure whereby the countries concerned agree to
    recognize the validity of the original, national marketing
    authorization.  Priority
    Review/Standard Review (United States) and Accelerated Review
    (European Union)
      Pharmaceutical
    Coverage, Pricing and Reimbursement
  FDA-approved
 80




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
    An annual, nondeductible fee on any entity that manufactures or
    imports certain branded prescription drugs and biologic agents;
    A new Medicare Part D coverage gap discount program, in
    which pharmaceutical manufacturers who wish to have their drugs
    covered under Part D must offer discounts to eligible
    beneficiaries during their coverage gap period (the donut
    hole); and
    A new formula that increases the rebates a manufacturer must pay
    under the Medicaid Drug Rebate Program.        Other
    Healthcare Laws and Compliance Requirements
   81




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§ 1320a-7b,
        Regulation
    of Diagnostic Tests
     82




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in vitro in vitro
  Patents
    and Proprietary Rights
    2020-2021
 83




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CO-338 2022-2024
  CO-338 CO-338
        non-U.S. jurisdictions
 84




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Plan of
    Operation
    
    continue with the clinical development of our product
    candidates, including the clinical trials for CO-101 and
    CO-338; and
    continue with the preclinical development of CO-1686, looking
    toward the filing of an IND in the first quarter of 2012, and
    the commencement of a Phase I clinical trial in the first half
    of 2012.    Manufacturing
     85




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scale-up
  and/or
  form CO-338,
    Sales and
    Marketing
   86




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Employees
    Facilities
    Legal
    Proceedings
   87




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MANAGEMENT  Executive
    Officers and Directors
    Name

Age

PositionPatrick J. Mahaffy


48


President and Chief Executive Officer; DirectorErle T. Mast


48


Executive Vice President and Chief Financial OfficerAndrew R. Allen, Ph.D.


44


Executive Vice President of Clinical and Pre-Clinical
    Development and Chief Medical OfficerGillian C. Ivers-Read


57


Executive Vice President, Technical Operations and Chief
    Regulatory OfficerBrian G. Atwood


58


DirectorM. James Barrett, Ph.D.


69


DirectorJames C. Blair, Ph.D.


72


DirectorPaul Klingenstein


53


DirectorEdward J. McKinley


59


DirectorJohn C. Reed, M.D., Ph.D.


52


DirectorThorlef Spickschen


70


Director   Executive
    Officers
  Patrick J. Mahaffy
  Erle T. Mast
  Dr. Andrew R. Allen
 88




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Gillian C. Ivers-Read Ms. Ivers-Read
  Directors
  Brian G. Atwood
  Dr. M. James Barrett
  Dr. James C. Blair
 89




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Paul Klingenstein
  Edward J. McKinley
  Dr. John C. Reed 1995-2005.
  Dr. Thorlef Spickschen
 90




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Composition
    of the Board of Directors
  Rule 10A-3
  Board
    Committees and Independence
  Rule 10A-3 Rule 10A-3,
    Role of
    the Board in Risk Oversight
   91




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day-to-day day-to-day
  Term and
    Class of Directors
      Term of
    Executive Officers
    Director
    Compensation
    Board
    Committees
    Audit
    Committee
  Rule 10A-3 Regulation S-K.
   92




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Compensation
    Committee
  Rule 16b-3
    Nominating
    and Corporate Governance Committee
      Compensation
    Committee Interlocks and Insider Participation
    Limitation
    on Liability and Indemnification of Directors and
    Officers
    
    for any breach of the directors or officers duty of
    loyalty to us or our stockholders; 93




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
    for acts or omissions not in good faith or which involve
    intentional misconduct or a knowing violation of law;
    under Section 174 of the Delaware General Corporation Law
    (unlawful dividends or stock repurchases); or
    for any transaction from which a director or officer derives an
    improper personal benefit.                Code of
    Business Ethics
  Form 8-K www.clovisoncology.com
   94




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EXECUTIVE
    AND DIRECTOR COMPENSATION  Compensation
    Discussion and Analysis
    
    Patrick J. Mahaffy, our President and Chief Executive Officer;
    Erle T. Mast, our Executive Vice President and Chief Financial
    Officer;
    Gillian C. Ivers-Read, our Executive Vice President, Technical
    Operations and Chief Regulatory Officer; and
    Andrew R. Allen, our Executive Vice President of Clinical and
    Pre-Clinical Development and Chief Medical Officer.  Compensation
    Overview and Objectives
    Determination
    of Compensation
       95




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Components
    of Compensation for Fiscal 2010
    Base
    Salary
    Annual
    Discretionary Performance Bonuses
      Equity
    Compensation
      Retirement
    Benefits
   96




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Other
    Benefits
    At-Will
    Employment Agreements
  Ms. Ivers-Read,
  Compensation
    Decisions Relating to Fiscal Year 2011
  2011
    Option Grants
  180-day lock-up
  Compensation
    Risk Management
    
    Base salary: Base salary is a fixed portion of overall
    compensation that is set based on factors such as the scope of
    an employees responsibilities, and which provides income
    regardless of our short-term performance. Our board of directors
    does not believe that base salary creates an incentive for our
    employees to take undue risks.
    Bonus programs: Bonuses are designed to reward employees for
    achieving annual company-wide performance goals that are
    important to our success, and intended to compensate our
    employees for achieving such goals. Although the board of
    directors has historically based bonuses on the achievement of
    company-wide goals, the actual amount of any bonus is subject to
    board of directors discretion. For these reasons, our board of
    directors does not believe that our bonus programs encourage
    employees to take risks which could have an adverse effect on us.
    Equity compensation: Equity awards are designed to encourage our
    employees to align their interests with the long-term interests
    of our stockholders. Our board of directors believes that equity
    compensation discourages our employees from taking unnecessary
    risks because the ultimate value of the equity awards is
    determined based on the long-term appreciation in the value of
    our stock. 97




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Executive
    Compensation
    Summary
    Compensation Table
  All OtherSalary

Bonus

compensation(1)

TotalName and principal position

Year

($)

($)

($)

($)Patrick J. Mahaffy


2010



375,000



75,000



9,800



459,800President and Chief Executive OfficerErle T. Mast


2010



325,000



52,000



9,208



386,208EVP, Chief Financial OfficerGillian C. Ivers-Read


2010



325,000



52,000



9,208



386,208EVP, Technical Operations and Chief Regulatory OfficerAndrew R. Allen


2010



325,000



52,000



9,208



386,208EVP of Clinical and Pre-Clinical Development and Chief Medical
    Officer    (1)
    
    Represents the matching contributions made during 2010 to our
    401(k) plan on behalf of each named executive officer.  Narrative
    Disclosure Relating to Summary Compensation Table
    Outstanding
    Equity Awards at Fiscal Year End
    Market value ofNumber of shares or

shares or units ofunits of stock that

stock that havehave not vested

not vestedName

(#)(1)

($)(2)Patrick J. Mahaffy


792,969



896,055Erle T. Mast


264,323



298,685Gillian C. Ivers-Read


264,323



298,685Andrew R. Allen


264,323



298,685    (1)
    
    The restricted stock held by the named executive officers was
    granted in May 2009 and was 25% vested as of the date of grant,
    and thereafter 1/48th of the restricted stock vests on each
    monthly anniversary of the date of grant thereafter. In the
    event that a named executive officers employment is
    terminated by us without cause within six months
    following a change in control of the Company, 100% of the
    unvested shares of restricted stock will immediately vest upon
    such termination.(2)
    
    Represents the estimated market value of the shares on
    December 31, 2010 of $1.13 per share. 98




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Option
    Exercises and Stock Vested
  Restricted stock awardsNumber of shares

Value realized onName

acquired on vesting (#)

vesting
    ($)(1)Patrick J. Mahaffy


328,125



347,813Erle T. Mast


109,375



115,938Gillian C. Ivers-Read


109,375



115,937Andrew R. Allen


109,375



115,937    (1)
    
    Represents the aggregate value realized upon vesting based on
    the estimated market value on each applicable vesting date of
    $1.06 per share.  Potential
    Payments Upon a Termination or Change in Control
    Director
    Compensation
  Director
    Compensation Table
    Option awardsName

($)(1)(2)

Total ($)Brian G. Atwood


13,800



13,800M. James Barrett


13,800



13,800James C. Blair


13,800



13,800Paul Klingenstein


13,800



13,800Edward J. McKinley


13,800



13,800John C. Reed


13,800



13,800Thorlef Spickschen


13,800



13,800    (1)
    
    The directors each received a grant of options to purchase
    20,000 shares of our common stock on December 2, 2010.
    As of December 31, 2010, each of the directors other than
    Dr. Blair had a total of 95,000 options outstanding.
    Dr. Blair exercised his 95,000 options for shares of our
    restricted common stock.(2)
    
    Amount represents the fair value of the awards on the date of
    grant computed in accordance with FASB ASC Topic 718. The
    assumptions used in the valuation of these awards are consistent
    with the valuation methodologies specified in the notes to our
    financial statements included elsewhere in this prospectus.  Narrative
    Disclosure relating to Director Compensation Table
  Stock
    Option Grants
   99




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Employee
    Benefit Plans
  2009
    Equity Incentive Plan
        2011
    Equity Incentive Plan
      2011
    Employee Stock Purchase Plan
   100




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101




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CERTAIN
    RELATIONSHIPS AND RELATED PARTY TRANSACTIONS    Preferred
    Stock and Convertible Promissory Note Issuances
  Series A-1 Series A-2
  PrincipalSeries A-1


Series A-2


Series B


Amount ofConvertible


Convertible


Convertible


ConvertibleCommon


Preferred


Preferred


Preferred


PromissoryStock


Stock


Stock


Stock


NotesStockholders beneficially owning 5% or more of our voting
    securitiesEntities affiliated with Domain Associates






1,206,897



1,206,897



2,612,330



$4,784,000Entities affiliated with New Enterprise Associates






1,206,897



1,206,897



2,612,330



$4,784,000Entities affiliated with Versant Ventures






862,069



862,069



1,865,950



$3,418,000Entities affiliated with Aberdare Ventures






517,241



517,241



1,119,570



$2,050,000Abingworth Bioventures V, L.P.






517,241



517,241



1,119,570



$2,050,000Directors and Executive OfficersPatrick J. Mahaffy


1,750,000



51,724



51,724



111,957



$206,000Erle T. Mast


583,334



6,897



6,897



14,928



$28,000Andrew R. Allen


583,333



10,345



10,345



22,391



$40,000Gillian C. Ivers-Read


583,333



6,897



6,897



14,928



$28,000Brian G. Atwood


















M. James Barrett


















James C. Blair


















Paul Klingenstein


















Edward J. McKinley






103,448



103,448



223,914



$410,000John C. Reed














Thorlef Spickschen






17,241



17,241



37,319



$68,000Price Per Share


$0.001



$2.00



$3.00



$4.62



N/ADate of Purchase


May 12, 2009



May 15, 2009



November 9, 2009



November 18, 2009



May 25, 2011   Restricted
    Stock Purchase Agreements
   102




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lock-up
  Convertible
    Promissory Notes
    Voting
    Agreement
    Right of
    First Refusal and Co-Sale Agreement
    Investors
    Rights Agreement
    Director
    Compensation
    Employment
    Agreements
    Indemnification
    Agreements
   103




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Stock
    Option Awards
  180-day lock-up
  Policies
    and Procedures Regarding Transactions with Related
    Persons
      
    the risks, costs and benefits to us;
    the impact on a directors independence in the event the
    related person is a director, immediate family member of a
    director or an entity with which a director is affiliated;
    the terms of the transaction;
    the availability of other sources for comparable services or
    products; and
    the terms available to or from, as the case may be, unrelated
    third parties or to or from our employees generally.   104




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PRINCIPAL
    STOCKHOLDERS    
    each person or group of affiliated persons who are known by us
    to own beneficially more than 5% of our common stock;
    each member of our board of directors and each of our named
    executive officers; and
    all members of our board of directors and our named executive
    officers as a group.      c/o Clovis
  105




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Prior to This Offering

After This OfferingNumber of

Percent of

Number of

Percent ofShares

Shares

Shares

SharesBeneficially

Beneficially

Beneficially

BeneficiallyName Of Beneficial Owner

Owned

Owned

Owned

OwnedStockholders beneficially owning 5% or more of our common
    stockEntities affiliated with Domain Associates


5,121,124
(1)


20.6
%Entities affiliated with New Enterprise Associates, Inc.


5,026,124
(2)


20.2
%Entities affiliated with Versant Ventures


3,590,088
(3)


14.4
%Entities affiliated with Aberdare Ventures


2,154,052
(4)


8.7
%Abingworth Bioventures V, L.P.


2,154,052
(5)


8.7
%Pfizer, Inc.



(6)


Officers and DirectorsPatrick J. Mahaffy


2,565,405



10.3
%Erle T. Mast


612,056
(7)


2.4
%Andrew R. Allen


626,414
(8)


2.5
%Gillian C. Ivers-Read


612,055
(9)


2.4
%Brian G. Atwood


3,685,088
(10)


14.8
%M. James Barrett


5,121,104
(11)


20.5
%James C. Blair


5,121,124
(12)


20.6
%Paul Klingenstein


2,249,052
(13)


9.0
%Edward J. McKinley


525,810
(14)


2.1
%John C. Reed


95,000
(15)


*Thorlef Spickschen


166,801
(16)


*All directors and named executive officers as a group
    (11 persons)


21,379,909



82.0
%    *
    
    Represents beneficial ownership of less than 1% of our common
    stock.(1)
    
    Includes 4,941,835 shares of common stock owned by Domain
    Partners VII, L.P., 84,289 shares of common stock owned by
    DP VII Associates, L.P. and 95,000 shares of common stock
    owned by Domain Associates, L.L.C. With respect to the shares
    owned by Domain Partners VII, L.P. and DP VII Associates, L.P.,
    the managing members of One Palmer Square Associates VII,
    L.L.C., the general partner of Domain Partners VII, L.P. and DP
    VII Associates, L.P., share voting and investment power with
    respect to these shares. With respect to the shares owned by
    Domain Associates, L.L.C., voting and investment power is shared
    among the managing members. Several managing members of Domain
    Associates, L.L.C. are also managing members of One Palmer
    Square Associates VII, L.L.C. Domain Associates is located at
    One Palmer Square, Suite 515, Princeton, NJ 08542.(2)
    
    Includes (i) 5,006,124 shares of common stock held of
    record by New Enterprise Associates 13, L.P. (NEA 13); and
    (ii) 20,000 shares of common stock held of record by
    NEA Ventures 2009, L.P. (Ven 2009). The shares directly held by
    NEA 13 are indirectly held by NEA Partners 13, L.P. (NEA
    Partners 13), the sole general partner of NEA 13, NEA 13 GP, LTD
    (NEA 13 LTD), the sole general partner of NEA Partners 13 and
    each of the individual Directors of NEA 13 LTD. The individual
    Directors (collectively, the Directors) of NEA 13
    LTD are M. James Barrett (a member of our board of directors),
    Peter J. Barris, Forest Baskett, Ryan D. Drant, Patrick J.
    Kerins, Krishna Kittu Kolluri, C. Richard Kramlich,
    David M. Mott, Scott D. Sandell, Ravi Viswanathan and Harry R.
    Weller. The shares directly held by Ven 2009 are indirectly held
    by Karen P. Welsh, the general partner of Ven 2009. NEA 13, NEA
    Partners 13, NEA 13 LTD and the Directors share voting and
    dispositive power with regard to the shares directly held by NEA
    13. Karen P. Welsh, the general partner of Ven 2009, holds
    voting and dispositive power over the shares held by Ven 2009.
    All indirect holders of the above-referenced shares disclaim
    beneficial ownership of all applicable shares except to the
    extent of their actual pecuniary interest therein. The principal
    business address of New Enterprise Associates, Inc. is 1954
    Greenspring Drive, Suite 600, Timonium, MD 21093.(3)
    
    Includes 3,567,613 shares of common stock held of record by
    Versant Venture Capital IV, L.P. and 22,475 shares of
    common stock owned by Versant Side Fund IV, L.P. Voting and
    investment power over the shares held of record by Versant
    Venture Capital IV, L.P., and Versant Side Fund IV, L.P. is held
    by Versant 106




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Ventures IV, LLC, their sole general partner. Brian G.
    Atwood, a member of our board of directors,  is a managing
    member of Versant Ventures IV, LLC but he disclaims beneficial
    ownership of these securities, except to the extent of his
    pecuniary interest therein, and the options held by him. The
    individual managing members of Versant Ventures IV, LLC are
    Brian G. Atwood, Bradley J. Bolzon, Samuel D. Colella, Ross A.
    Jaffe, William J. Link, Kirk G. Nielsen, Robin L. Praeger,
    Rebecca B. Robertson, Camille D. Samuels, Charles M. Warden and
    Kevin J. Wasserstein, all of whom share voting and investment
    power with respect to these shares. Each individual managing
    member disclaims beneficial ownership of these shares, except to
    the extent of their pecuniary interest in such shares. The
    address of each entity affiliated with Versant Ventures is 3000
    Sand Hill Road, Building Four, Suite 210, Menlo Park, CA 94025.(4)
    
    Includes 2,111,899 shares of common stock owned by Aberdare
    Ventures IV, L.P. and 42,153 shares of common stock owned
    by Aberdare Partners IV, L.P. Mr. Klingenstein is a
    managing director of Aberdare GP IV, LLC, the general partner of
    Aberdare Ventures IV, L.P. and Aberdare Partners IV, L.P. With
    respect to the shares owned by Aberdare Ventures IV, L.P. and
    Aberdare Partners IV, L.P., voting and investment power is
    shared among the managing members of Aberdare GP IV, LLC.
    Mr. Klingenstein disclaims beneficiary ownership of such
    shares except to the extent of his pecuniary interest therein.
    Aberdare Ventures is located at One Embarcadero Center,
    Suite 4000, San Francisco, CA 94111.(5)
    
    Abingworth LLP is the Manager of Abingworth
    Bioventures V L.P. The investment committee of
    Abingworth LLP comprising Dr. Joseph Anderson, Michael
    Bigham, Dr. Stephen Bunting and Dr. Jonathan MacQuitty
    share voting and investment power with respect to these shares,
    and disclaim beneficial ownership except to the extent of their
    pecuniary interest therein. Abingworth LLP is located at
    38 Jermyn Street, London, SW1Y 6DN, United Kingdom.(6)
    
    Pfizer, Inc. is located at 235 East 42nd Street, New York, NY
    10017.(7)
    
    Includes 200,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days.(8)
    
    Includes 200,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days.(9)
    
    Includes 200,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days.(10)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days, 3,567,613 shares of common stock owned by
    Versant Venture Capital IV, L.P. and 22,475 shares of
    common stock owned by Versant Side Fund IV, L.P. Versant
    Ventures IV, L.L.C. is the general partner of Versant Venture
    Capital IV, L.P. and Versant Side Fund IV, L.P. Versant Ventures
    IV, L.L.C. shares voting and dispositive power over the shares
    of common stock held by Versant Venture Capital IV, L.P. and
    Versant Side Fund IV, L.P. Mr. Atwood is a managing member
    of Versant Ventures IV, L.L.C. Mr. Atwood disclaims
    beneficial ownership of these securities, except to the extent
    of his pecuniary interest therein.(11)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days. See footnote (2) above regarding
    Dr. Barretts relationship with New Enterprise
    Associates, Inc. and its affiliated entities. Dr. Barrett
    disclaims beneficial ownership of the shares held by NEA 13 and
    Ven 2009, referenced in footnote (2) above, except to the
    extent of his actual pecuniary interest therein.
    Dr. Barrett does not have voting or dispositive power over
    the shares held of record by Ven 2009.(12)
    
    Includes 4,941,835 shares of common stock owned by Domain
    Partners VII, L.P., 84,289 shares of common stock owned by
    DP VII Associates, L.P. and 95,000 shares of common stock owned
    by Domain Associates, L.L.C. Dr. Blair is a managing member
    of One Palmer Square Associates VII, L.L.C., which is the
    general partner of Domain Partners VII, L.P. and DP VII
    Associates, L.P. Dr. Blair is also a managing member of
    Domain Associates, L.L.C. With respect to the shares owned by
    Domain Associates, L.L.C., voting and investment power is shared
    among the managing members. Several managing members of Domain
    Associates, L.L.C. are also managing members of One Palmer
    Square Associates VII, L.L.C. Dr. Blair disclaims
    beneficial ownership of these shares except to the extent of his
    pecuniary interest in such shares.(13)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days, 2,111,899 shares of common stock owned by
    Aberdare Ventures IV, L.P. and 42,153 shares of 107




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common stock owned by Aberdare Partners IV, L.P.
    Mr. Klingenstein is a managing director of Aberdare GP IV,
    LLC, the general partner of Aberdare Ventures IV, L.P. and
    Aberdare Partners IV, L.P. With respect to the shares owned by
    Aberdare Ventures IV, L.P. and Aberdare Partners IV, L.P.,
    voting and investment power is shared among the managing members
    of Aberdare GP IV, LLC. Mr. Klingenstein disclaims
    beneficiary ownership of such shares except to the extent of his
    pecuniary interest therein.(14)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days.(15)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days.(16)
    
    Includes 95,000 shares of common stock subject to
    outstanding options which are exercisable within the next
    60 days. 108




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DESCRIPTION
    OF CAPITAL STOCK  The following summary describes our capital stock and the
    material provisions of our amended and restated certificate of
    incorporation and our amended and restated bylaws, which will
    become effective upon the closing of this offering, the
    registration rights agreement to which we and certain of our
    stockholders are parties and of the Delaware General Corporation
    Law. Because the following is only a summary, it does not
    contain all of the information that may be important to you. For
    a complete description, you should refer to our amended and
    restated certificate of incorporation, amended and restated
    bylaws and registration rights agreement, copies of which have
    been filed as exhibits to the registration statement of which
    this prospectus is part.
  General
    Common
    Stock
        Undesignated
    Preferred Stock
   109




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##### Table of Contents



Registration
    Rights
  Form S-1 Form S-3,
  Anti-Takeover
    Provisions of Delaware Law
    Charter
    and Bylaws Anti-Takeover Provisions
  Classified
    Board of Directors
    Size
    of Board of Directors and Removal of Directors
    
    the number of directors will be fixed from time to time
    exclusively pursuant to a resolution adopted by our board of
    directors, but must consist of not less than three directors,
    which will prevent stockholders from circumventing the
    provisions of our classified board of directors;
    directors may be removed only for cause; and 110




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##### Table of Contents




    vacancies on our board of directors may be filled only by a
    majority of directors then in office, even though less than a
    quorum.  Authorized
    Preferred Stock
    No
    Stockholder Action by Written Consent
    Calling
    of Special Meetings of Stockholders
    Advance
    Notice Requirements for Stockholder Proposals and Director
    Nominations
    Limitation
    on Liability and Indemnification of Directors and
    Officers
    Transfer
    Agent and Registrar
    Listing
   111




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##### Table of Contents



SHARES ELIGIBLE
    FOR FUTURE SALE          Rule 144
    
    1% of the number of shares of our common stock then outstanding,
    which will equal
    approximately           shares,
    or           shares
    if the underwriters exercise their over-allotment option in
    full, immediately after this offering, based on the number of
    shares of our common stock outstanding upon the closing of this
    offering; or
    the average weekly trading volume of our common stock on the
    NASDAQ Global Market during the four calendar weeks preceding
    the filing of a notice on Form 144 with respect to the sale. 112




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##### Table of Contents



Rule 701
      Lock-up
    Agreements
  lock-up lock-up lock-up lock-up
  180-day
  
    during the last 17 days of the
    180-day
    restricted period we issue an earnings release or announce
    material news or a material event; or
    prior to the expiration of the
    180-day
    restricted period, we announce that we will release earnings
    results during the
    16-day
    period beginning on the last day of the
    180-day
    period,  18-day
  lock-up lock-up
  Equity
    Incentive Plans
  Form S-8 lock-up
  Registration
    Rights
   113




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##### Table of Contents



Initial
    Public Offering Price
    
    the history of, and prospects for, our company and the industry
    in which we compete;
    our past and present financial performance;
    an assessment of our management;
    the present state of our development;
    the prospects for our future earnings;
    the prevailing conditions of the applicable U.S. securities
    market at the time of this offering;
    market valuations of publicly traded companies that we and the
    representatives of the underwriters believe to be comparable to
    us; and
    other factors deemed relevant.   114




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##### Table of Contents



MATERIAL
    U.S. FEDERAL INCOME AND ESTATE TAX CONSIDERATIONS  non-U.S. holder non-U.S. holder. non-U.S. holder
  
    a nonresident alien individual;
    a corporation (or any other entity treated as a corporation for
    U.S. federal income tax purposes) created or organized in
    or under the laws of a jurisdiction other than the United
    States, any state thereof or the District of Columbia;
    an estate other than one the income of which is subject to
    U.S. federal income taxation regardless of its
    source; or
    a trust other than a trust if it (A) is subject to the
    primary supervision of a court within the United States and the
    control of one or more U.S. persons having the authority to
    control all substantial decisions of the trust, or (B) has
    a valid election in effect to be treated as a U.S. person.    non-U.S. holder
  non-U.S. holders non-U.S. taxing non-U.S. holder non-U.S. income,
    Dividends
   115




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##### Table of Contents



non-U.S. non-U.S. holder Form W-8BEN
  non-U.S. holder non-U.S. holder non-U.S. holder Form W-8ECI non-U.S. holder non-U.S. corporation
  Gain on
    Disposition of Common Stock
  non-U.S. holder
  
    the gain is effectively connected with the
    non-U.S. holders
    conduct of a trade or business in the United States (and, if
    required by an applicable income tax treaty, is attributable to
    a U.S. permanent establishment); or
    we are or have been a U.S. real property holding
    corporation, as defined below, at any time within the five-year
    period preceding the disposition or the
    non-U.S. holders
    holding period, whichever period is shorter (the relevant
    period).  non-U.S. holder non-U.S. holders
    non-U.S. holder
  Backup
    Withholding and Information Reporting
  non-U.S. holder
 116




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##### Table of Contents



non-U.S. holder
  U.S.
    Federal Estate Tax
  non-U.S. holder non-U.S. holders
  Legislation
    Relating to Foreign Accounts
   117




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##### Table of Contents



UNDERWRITING    Number ofName

SharesJ.P. Morgan Securities LLCCredit Suisse Securities (USA) LLCLeerink Swann LLCTotal           Without


With fullover-allotment


over-allotmentexercise


exercisePer Share

$



$Total

$



$      118




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##### Table of Contents



180-day 180-day 16-day 180-day 18-day
  lock-up 180-day 180-day 16-day 180-day 18-day lock-up and/or
       119




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##### Table of Contents



over-the-counter
    
    the information set forth in this prospectus and otherwise
    available to the representatives;
    our prospects and the history and prospects for the industry in
    which we compete;
    an assessment of our management;
    our prospects for future earnings;
    the general condition of the securities markets at the time of
    this offering;
    the recent market prices of, and demand for, publicly traded
    common stock of generally comparable companies; and
    other factors deemed relevant by the underwriters and us.       120




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##### Table of Contents




    to legal entities which are authorized or regulated to operate
    in the financial markets or, if not so authorized or regulated,
    whose corporate purpose is solely to invest in securities;
    to any legal entity which has two or more of (1) an average
    of at least 250 employees during the last financial year;
    (2) a total balance sheet of more than 43,000,000 and
    (3) an annual net turnover of more than 50,000,000,
    as shown in its last annual or consolidated accounts;
    to fewer than 100 natural or legal persons (other than qualified
    investors as defined in the E.U. Prospectus Directive) subject
    to obtaining the prior consent of the book-running managers for
    any such offer; or
    in any other circumstances which do not require the publication
    by the Issuer of a prospectus pursuant to Article 3 of the
    Prospectus Directive.     121




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##### Table of Contents



LEGAL
    MATTERS   EXPERTS   WHERE YOU
    CAN FIND MORE INFORMATION  Form S-1
  1-800-SEC-0330. www.sec.gov
  www.clovisoncology.com
 122




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##### Table of Contents



INDEX TO
    CONSOLIDATED FINANCIAL STATEMENTS  Index to Consolidated Financial StatementsReport of Independent Registered Public
    Accounting Firm


F-2Consolidated Statements of Operations


F-3Consolidated Balance Sheets


F-4Consolidated Statements of Convertible Preferred
    Stock and Stockholders Deficit


F-5Consolidated Statements of Cash Flows


F-6Notes to Consolidated Financial Statements


F-7  F-1




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##### Table of Contents



Report of
    Independent Registered Public Accounting Firm             
     F-2




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC
    (A Development Stage Enterprise)Consolidated Statements of Operations
  CummulativePeriod from








fromFor the Year


April 20, 2009








April 20, 2009Ended


(Inception) to








(Inception) toDecember 31,


December 31,


Three Months Ended March 31,


March 31,2010


2009


2011


2010


2011(unaudited)


(unaudited)


(unaudited)(in thousands, except per share amounts)Revenues

$



$



$



$



$
Expenses:Research and development


22,323



1,762



7,041



3,259



31,126General and administrative


4,302



2,209



1,405



830



7,916Acquired in-process research and development


12,000



13,085











25,085Operating loss


(38,625
)


(17,056
)


(8,446
)


(4,089
)


(64,127
)Other income (expense), net


795



(43
)


118



(2
)


870Net loss

$
(37,830
)

$
(17,099
)

$
(8,328
)

$
(4,091
)

$
(63,257
)Basic and diluted net loss per common share

$
(9.85
)

$
(5.30
)

$
(2.15
)

$
(1.07
)

$
(17.45
)Basic and diluted weighted average common shares outstanding


3,842



3,225



3,877



3,832



3,625Pro forma basic and diluted net loss per common share (unaudited)

$
(1.52
)





$
(0.33
)





$
(3.20
)Pro forma basic and diluted weighted average common shares
    outstanding (unaudited)


24,851







24,886







19,784    F-3




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC
    (A Development Stage Enterprise)Consolidated Balance
    Sheets
  March 31, 2011Pro FormaDecember 31,





Equity2010


2009


March 31, 2011


(Deficit)(unaudited)


(unaudited)(in thousands, except for share amounts)AssetsCurrent assets:Cash and cash equivalents

$
10,508


$
57,311


$
4,602Available for sale securities


11,791







9,324Prepaid research and development expenses


1,826



1,105



1,081Other current assets


1,096



66



1,459Total current assets


25,221



58,482



16,466Property and equipment, net


951



264



1,030Prepaid research and development expenses






810



Other assets


28



18



35Total assets

$
26,200


$
59,574


$
17,531Liabilities and stockholders equity (deficit)Current liabilities:Accounts payable

$
1,400


$
534


$
1,107Accrued research and development expenses


3,195



388



3,248Other accrued expenses


740



211



571Total current liabilities


5,335



1,133



4,926Non-current liabilities


115







129Commitments and contingencies (Note 8)Convertible preferred stock, $0.001 par value per share,
    36,296,552 shares authorized;Series A-1
    convertible preferred stock, 5,044,828 shares authorized,
    issued and outstanding at December 31, 2010 and 2009 and
    March 31, 2011, and no shares at March 31, 2011
    (proforma); liquidation preference of $10,090


9,916



9,916



9,916


$
Series A-2
    convertible preferred stock, 5,044,828 shares authorized,
    issued and outstanding at December 31, 2010 and 2009 and
    March 31, 2011, and no shares at March 31, 2011
    (proforma); liquidation preference of $15,135


15,135



15,135



15,135



Series B convertible preferred stock,
    10,919,540 shares authorized, issued and outstanding at
    December 31, 2010 and 2009 and March 31, 2011, and no
    shares at March 31, 2011 (proforma); liquidation preference
    of $50,448


50,448



50,448



50,448



Stockholders equity (deficit):Common stock, $0.001 par value per share,
    55,000,000 shares authorized; 3,877,500, 3,832,500, and
    3,879,600 issued and outstanding at December 31, 2010 and
    2009 and March 31, 2011, respectively, and 24,888,796 at
    March 31, 2011 (pro forma)


4



4



4



25Additional paid-in capital


134



37



195



75,673Accumulated other comprehensive income


42







35



35Deficit accumulated during development stage


(54,929
)


(17,099
)


(63,257
)


(63,257
)Total stockholders equity (deficit)


(54,749
)


(17,058
)


(63,023
)

$
12,476Total liabilities, convertible preferred stock and
    stockholders equity (deficit)

$
26,200


$
59,574


$
17,531    F-4




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##### Table of Contents





CLOVIS
    ONCOLOGY, INC
    (A Development Stage Enterprise)Consolidated Statements of
    Convertible Preferred Stock and Stockholders
    Deficit
  DeficitAccumulated


Accumulated


TotalConvertible









Additional


Other


During


StockholdersPreferred Stock



Common Stock


Paid-In


Comprehensive


Development


Equity


ComprehensiveShares


Amount



Shares


Amount


Capital


Income


Stage


(Deficit)


Loss(in thousands, except for share amounts)Balance at April 20, 2009 (inception)





$








$



$



$



$



$
Issuance of common stock to founders at $.001 per share











3,500,000



4















4Issuance of convertible preferred stock; $2.00, $3.00 and $4.62
    per share for
    series A-1,
    A-2 and B,
    respectively, net net of issuance costs of $174


21,009,196



75,499
























Exercise of stock options











332,500







33











33Share-based compensation expense



















4











4Net loss



























(17,099
)


(17,099
)

$
(17,099
)Balance at December 31, 2009


21,009,196



75,499




3,832,500



4



37







(17,099
)


(17,058
)

$
(17,099
)Exercise of stock options











45,000







29











29Share-based compensation expense



















68











68Net unrealized gain on available for sale securities























42







42


$
42Net loss



























(37,830
)


(37,830
)


(37,830
)Balance at December 31, 2010


21,009,196



75,499




3,877,500



4



134



42



(54,929
)


(54,749
)

$
(37,788
)Exercise of stock options (unaudited)











2,100







2











2Share-based compensation expense (unaudited)



















59











59Net unrealized loss on available for sale securities (unaudited)























(7
)






(7
)

$
(7
)Net loss (unaudited)



























(8,328
)


(8,328
)


(8,328
)Balance at March 31, 2011 (unaudited)


21,009,196


$
75,499




3,879,600


$
4


$
195


$
35


$
(63,257
)

$
(63,023
)

$
(8,335
)     F-5




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC
    (a development stage enterprise)Consolidated Statements of Cash
    Flows
  CumulativePeriod from









fromFor the


April 20, 2009









April 20, 2009Year Ended


(Inception) to



Three Months


(Inception) toDecember 31,


December 31,



Ended March 31,


March 31,2010


2009



2011


2010


2011(unaudited)


(unaudited)


(unaudited)(in thousands)Operating activitiesNet loss

$
(37,830
)

$
(17,099
)


$
(8,328
)

$
(4,091
)

$
(63,257
)Adjustments to reconcile net loss to net cash used in operating
    activities:Depreciation


83



6




42



12



131Share-based compensation expense


68



4




59



4



131Amortization of premiums and discounts on available for sale
    securities


320








61



11



381Gain on sale of available for sale securities


(18
)















(18
)Changes in operating assets and liabilities:Prepaid and accrued research and development expenses


2,896



(1,527
)



797



(386
)


2,166Other operating assets


(1,040
)


(84
)



(371
)


(324
)


(1,495
)Accounts payable


866



534




(294
)


(238
)


1,106Other accrued expenses


644



211




(154
)


101



701Net cash used in operating activities


(34,011
)


(17,955
)



(8,188
)


(4,911
)


(60,154
)Investing activitiesPurchases of property and equipment


(770
)


(270
)



(120
)


(74
)


(1,160
)Purchases of available for sale securities


(27,008
)











(20,232
)


(27,008
)Maturities and sales of available for sale securities


14,957








2,400







17,357Net cash (used in) provided by investing activities


(12,821
)


(270
)



2,280



(20,306
)


(10,811
)Financing activitiesProceeds from sale of convertible preferred and common stock,
    net of issuance costs






75,503












75,503Proceeds from stock option exercises


29



33




2







64Net cash provided by investing activities


29



75,536




2







75,567(Decrease) increase in cash and cash equivalents


(46,803
)


57,311




(5,906
)


(25,217
)


4,602Cash and cash equivalents at beginning of period


57,311








10,508



57,311



Cash and cash equivalents at end of period

$
10,508


$
57,311



$
4,602


$
32,094


$
4,602    F-6




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)NOTES TO CONSOLIDATED FINANCIAL
    STATEMENTS
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
  1.
    Nature of
    Business    Liquidity
    2.
    Summary
    of Significant Accounting Policies  Unaudited
    Interim Financial Data
   F-7




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   2.
    Summary
    of Significant Accounting Policies (Continued)  Unaudited
    Pro Forma Equity and Pro Forma Loss per Common Share
  Series A-1, Series A-2
    Basis of
    Presentation
      Use of
    Estimates
    Fair
    Value of Financial Instruments
   F-8




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   2.
    Summary
    of Significant Accounting Policies (Continued)  Cash,
    Cash Equivalents and Available for Sale Securities
      Property
    and Equipment
    EstimatedUseful LifeComputer hardware and software


3 yearsLeasehold improvements


6 yearsLaboratory and office equipment


7 yearsFurniture and fixtures


10 years   Long-Lived
    Assets
    Research
    and Development Expense
   F-9




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   2.
    Summary
    of Significant Accounting Policies (Continued)    Acquired
    In-Process Research and Development Expense
    Share-Based
    Compensation Expense
    Concentration
    of Credit Risk
    Foreign
    Currency
    Income
    Taxes
   F-10




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   2.
    Summary
    of Significant Accounting Policies (Continued)  Recently
    Adopted and Issued Accounting Standards
    3.
    Property
    and Equipment    March 31,


December 31,2011


2010


2009Furniture and fixtures

$
424


$
419


$
170Laboratory equipment


392



287



Leasehold improvements


140



139



49Computer equipment and software


122



116



45Office equipment


83



79



6Total property and equipment


1,161



1,040



270Less: accumulated depreciation


(131
)


(89
)


(6
)Property and equipment, net

$
1,030


$
951


$
264     4.
    Fair
    Value Measurements    Level 1:
    Quoted prices in active markets for identical assets or
    liabilities. The Companys Level 1 assets and
    liabilities consist of money market investments.Level 2:
    Observable inputs other than Level 1 prices, such as quoted
    prices for similar assets or liabilities in active markets or
    other inputs that are observable or can be corroborated by
    observable market data for substantially the full term of the
    assets or liabilities. The Companys Level 2 assets
    and liabilities include U.S. government obligations,
    U.S. government agency obligations and corporate debt
    securities.Level 3:
    Unobservable inputs that are supported by little or no market
    activity. F-11




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   4.
    Fair
    Value Measurements (Continued)     Description

Balance


Level 1


Level 2


Level 3March 31, 2011Money market

$
639


$
639


$



$
U.S. agency obligations


4,083







4,083



Corporate debt securities


1,220







1,220



U.S. government obligations


4,021







4,021



Total assets at fair value

$
9,963


$
639


$
9,324


$
December 31, 2010Money market

$
7,010


$
7,010


$



$
U.S. agency obligations


4,109







4,109



Corporate debt securities


3,656







3,656



U.S. government obligations


4,026







4,026



Total assets at fair value

$
18,801


$
7,010


$
11,791


$
December 31, 2009Money market

$
57,000


$
57,000


$



$
Total assets at fair value

$
57,000


$
57,000


$



$
    5.
    Available
    for Sale Securities    Cost orAmortized


Fair MarketCost Value


ValueMarch 31, 2011Due in one year or less

$
7,291


$
7,311Due after one year through two years


1,998



2,013Total

$
9,289


$
9,324December 31, 2010Due in one year or less

$
7,663


$
7,675Due after one year through two years


4,087



4,116Total

$
11,750


$
11,791  F-12




---



##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   5.
    Available
    for Sale Securities (Continued)    Cost or


Gross


GrossAmortized


Unrealized


Unrealized


Fair MarketCost Value


Gains


(Losses)


ValueMarch 31, 2011U.S. government agencies

$
4,070


$
13


$



$
4,083U.S. government obligations


4,001



20







4,021Corporate debt securities


1,218



2







1,220Total

$
9,289


$
35


$



$
9,324December 31, 2010U.S. government agencies

$
4,095


$
14


$



$
4,109U.S. government obligations


4,002



24







4,026Corporate debt securities


3,653



4



(1
)


3,656Total

$
11,750


$
42


$
(1
)

$
11,791     6.
    Convertible
    Preferred Stock and Stockholders Deficit  Common
    Stock
      Preferred
    Stock
  Series A-1, A-2, Series A-1, Series A-2 Series A-1, A-2
 F-13




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   6.
    Convertible
    Preferred Stock and Stockholders Deficit
    (Continued)    Series A-1, A-2
  Voting
    Rights
  Series A-1, A-2
  Dividends
  Series A-1, A-2 Series A-1, A-2
  Liquidation
  Series A-1, A-2 Series A-1, A-2
  Series A-1, A-2
 F-14




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   6.
    Convertible
    Preferred Stock and Stockholders Deficit
    (Continued)    Conversion
  Series A-1, A-2
  Series A-1, A-2
  7.
    Share-Based
    Compensation      Weighted-Weighted-


AverageAverage


Remaining


AggregateOption Shares


Exercise


Contractual


IntrinsicOutstanding


Price


Term (Years)


ValueBalance at April 20, 2009 (inception)





$
Granted


902,500



0.10Exercised


(332,500
)


0.10Balance at December 31, 2009


570,000



0.10



9.69Granted


699,500



1.06Exercised


(45,000
)


0.63Balance at December 31, 2010


1,224,500


$
0.63



9.14


$
613,715Vested and expected to vest at December 31, 2010


1,063,590


$
0.60



9.12


$
563,671Vested at December 31, 2010


306,667


$
0.26



8.85


$
265,467   F-15




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   7.
    Share-Based
    Compensation (Continued)  Weighted-Weighted-


AverageAverage


Remaining


AggregateOption Shares


Exercise


Contractual


IntrinsicOutstanding


Price


Term (Years)


ValueBalance at December 31, 2010


1,224,500


$
0.63Granted


1,549,900



1.13Exercised


(2,100
)


1.13Forfeited


(25,521
)


1.06Balance at March 31, 2011


2,746,779


$
0.91



9.48


$
611,929Vested and expected to vest at March 31, 2011


2,258,236


$
0.88



9.44


$
567,695Vested at March 31, 2011


327,626


$
0.30



8.62


$
272,934   Three Months Ended

Year Ended December 31,March 31, 2011

2010

2009Weighted-average fair value of options granted per share

$
0.75


$
0.72


$
0.07Intrinsic value of options exercised

$



$
19,200


$
Cash received from stock option exercises

$
2,373


$
28,500


$
33,250       Three Months Ended

Year Ended December 31,March 31, 2011

2010

2009Risk-free interest rate(a)


2.48
%


2.10
%


2.33
%Dividend yield










Volatility(b)


74
%


80
%


80
%Expected term (years)(c)


6.0



5.61



5.30    (a)
    
    Risk-free interest rate:The rate is based on the yield
    on the grant date of a zero-coupon U.S. Treasury bond whose
    maturity period approximates the options expected term.(b)
    
    Volatility:The expected volatility was estimated using
    peer data of companies in the biopharmaceutical industry with
    similar equity plans.(c)
    
    Expected life:The expected life of the award was
    estimated using peer data of companies in the biopharmaceutical
    industry with similar equity plans.   F-16




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   7.
    Share-Based
    Compensation (Continued)      TotalAvailable


Shares ofShares or


for Grant or


CommonOptions


Future


StockOutstanding


Issuance


Reserved2009 Equity Incentive Plan


1,224,500



1,398,000



2,622,500Series A-1
    convertible preferred stock


5,044,828







5,044,828Series A-2
    convertible preferred stock


5,044,828







5,044,828Series B convertible preferred stock


10,919,540







10,919,540Series C convertible preferred stock






15,287,356



15,287,35622,233,696



16,685,356



38,919,052     TotalAvailable


Shares ofShares or


for Grant or


CommonOptions


Future


StockOutstanding


Issuance


Reserved2009 Equity Incentive Plan


2,746,779



1,248,621



3,995,400Series A-1
    convertible preferred stock


5,044,828







5,044,828Series A-2
    convertible preferred stock


5,044,828







5,044,828Series B convertible preferred stock


10,919,540







10,919,540Series C convertible preferred stock






15,287,356



15,287,35623,755,975



16,535,977



40,291,952    8.
    Commitments    December 31, 20102011

$
6652012


7512013


3892014


2032015


190Thereafter


Total minimum lease payments

$
2,198   F-17




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
  9.
    License
    Agreements  CO-101
      CO-1686
   F-18




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
  10.
    Income
    Taxes      Year Ended December 31,2010


2009Federal income tax (benefit) at statutory rate


(34.0
)%


(34.0
)%State income tax benefit, net of federal benefit


(3.6
)


(4.4
)Tax credits


(12.9
)


Other


0.3



Increase to valuation allowance


50.2



38.4Effective income tax rate



%



%     December 31,2010


2009Deferred tax assets:Net operating loss carryforward

$
9,386


$
1,562Product acquisition costs


9,229



5,003Tax credit carryforwards


7,186



Accrued liabilities and other


57



6Total deferred tax assets


25,858



6,571Valuation allowance


(25,510
)


(6,541
)Deferred tax assets, net of valuation allowance


348



30Deferred tax liabilities:Prepaid expenses


(321
)


(19
)Depreciation


(27
)


(11
)Total deferred tax liabilities


(348
)


(30
)Net deferred tax assets

$



$
      F-19




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   10.
    Income
    Taxes (Continued)      11.
    Net Loss
    Per Common Share      For the


Period








CumulativeYear Ended


from April 20, 2009


Three Months


from April 20, 2009December 31,


(Inception) to


Ended March 31,


(Inception) to2010


December 31, 2009


2011


2010


March 31, 2011Common shares under option


1,225



570



2,747



570



2,747Convertible preferred stock


21,009



21,009



21,009



21,009



21,009Total potential dilutive shares


22,234



21,579



23,756



21,579



23,756   12.
    Employee
    Benefit Plan    13.
    Subsequent
    Events  Convertible
    Promissory Notes
   F-20




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##### Table of Contents



CLOVIS
    ONCOLOGY, INC.
    (A DEVELOPMENT STAGE ENTERPRISE)
    NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
  (INFORMATION
    AS OF MARCH 31, 2011, FOR THE THREE MONTHS ENDED MARCH 31, 2011
    AND 2010 AND THE PERIOD FROM APRIL 20, 2009 TO MARCH 31, 2011 IS
    UNAUDITED)
   13.
    Subsequent
    Events (Continued)    
    Immediately prior to the closing of a Qualified IPO (as defined
    below) the Notes shall automatically convert into shares of our
    common stock at a per share price equal to the price to the
    public for common stock issued in the Qualified IPO. A
    Qualified IPO is defined as an initial public
    offering with gross proceeds of at least $50 million with a
    per share price of at least $9.24 or as deemed to occur by the
    consent of the holders of 55% of the Companys convertible
    preferred stock.
    Upon the completion of an equity financing other than a
    Qualified IPO and at the election of holders of at least 55% of
    the outstanding principal amount of the Notes, the Notes will
    convert into shares of the securities issued in the equity
    financing at the per share price of the securities issued in
    such equity financing.
    Upon the maturity date of the Notes, they will automatically
    convert into either (1) shares of our Series C
    convertible preferred stock at the per share price set forth in
    the Companys Restated Certificate of Incorporation, or
    (2) shares of the most recent class of securities issued by
    the Company, if the Company has undertaken an offering of such
    securities for cash after the issuance of Series C
    convertible preferred stock at the price per share to the
    purchasers of the new securities.
    Upon an event of default, as defined in the agreements governing
    the Notes, and at the election of holders of at least 55% of the
    outstanding principal amount of the Notes, the Notes will
    convert into Series C convertible preferred stock or into a
    more recent class of securities issued by the Company for cash
    as described in the preceding bullet point.  Pfizer
    License Agreement for CO-338
  CO-338.
 F-21




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##### Table of Contents





Shares
  
  Common stock
     Prospectus
     J.P.
    Morgan
    Credit Suisse  Leerink
    Swann




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##### Table of Contents



PART II
    INFORMATION NOT REQUIRED IN PROSPECTUS
  Item 13.
    Other
    expenses of issuance and distribution.    AmountItem

to be PaidSecurities and Exchange Commission registration fee

$
17,357Financial Industry Regulatory Authority filing fee


15,450NASDAQ Global Market listing feeLegal fees and expensesAccountants fees and expensesPrinting expensesTransfer agent and registrar fees and expensesBlue Sky fees and expensesMiscellaneousTotal

$   Item 14.
    Indemnification
    of directors and Officers.  Limitation
    on liability and indemnification of directors and
    officers
       II-1




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##### Table of Contents



and/or
      Item 15.
    Recent
    sales of unregistered securities.      (1)
    On May 12, 2009, we sold an aggregate of
    3,500,000 shares of our common stock at a price per share
    of $0.001 to accredited investors, for an aggregate purchase
    price of $3,500.(2)
    On May 15, 2009, we sold an aggregate of
    5,044,828 shares of our
    series A-1
    convertible preferred stock at a price per share of $2.00 to
    accredited investors, for an aggregate purchase price of
    $10,089,656.(3)
    On November 9, 2009, we sold an aggregate of
    5,044,828 shares of our
    series A-2
    convertible preferred stock at a price per share of $3.00 to
    accredited investors, for an aggregate purchase price of
    $15,134,484. II-2




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##### Table of Contents



(4)
    On November 18, 2009, we sold an aggregate of
    10,919,540 shares of our series B convertible
    preferred stock at a price per share of $4.62 to accredited
    investors, for an aggregate purchase price of $50,448,275.(5)
    On May 25, 2011, we sold $20,000,000 aggregate principal
    amount of our 5% convertible promissory notes due 2012 to
    accredited investors, for an aggregate purchase price of
    $20,000,000.(6)
    On June 2, 2011, we sold $15,000,000 aggregate principal
    amount of our 5% convertible promissory notes due 2012 to
    Pfizer, Inc., an accredited investor, $7.0 million of which
    were issued as consideration for the execution of our license
    agreement with Pfizer, Inc. for
    CO-338 and
    $8.0 million of which were issued for an investment of
    $8.0 million of cash by Pfizer, Inc.(7)
    From April 20, 2009 through June 1, 2011, we issued an
    aggregate of 1,154,879 shares of our common stock at prices
    ranging from $0.10 to $1.13 per share to certain of our
    employees and directors pursuant to the exercise of stock
    options under the Clovis Oncology, Inc. 2009 Equity Incentive
    Plan (the 2009 Plan) for an aggregate purchase price
    of $935,675.    (1)
    From April 20, 2009 through June 1, 2011, we granted
    stock options to purchase an aggregate of 3,202,900 shares
    of our common stock with exercise prices ranging from $0.10 to
    $1.13 per share, to certain of our employees and directors under
    our 2009 Plan in connection with services provided by such
    parties to us.        Item 16.
    Exhibits
    and financial statement schedules.  (a) Exhibits
    (b) Financial Statement Schedules
 II-3




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##### Table of Contents



Item 17.
    Undertakings.  (a)
    The undersigned registrant hereby undertakes to provide to the
    underwriters at the closing specified in the underwriting
    agreement certificates in such denominations and registered in
    such names as required by the underwriters to permit prompt
    delivery to each purchaser.  (b)
    Insofar as indemnification for liabilities arising under the
    Securities Act of 1933 may be permitted to directors,
    officers and controlling persons of the registrant pursuant to
    our amended and restated certificate of incorporation or bylaws,
    or otherwise, the registrant has been advised that in the
    opinion of the Securities and Exchange Commission such
    indemnification is against public policy as expressed in the
    Securities Act and is, therefore, unenforceable. In the event
    that a claim for indemnification against such liabilities (other
    than the payment by the registrant of expenses incurred or paid
    by a director, officer or controlling person of the registrant
    in the successful defense of any action, suit or proceeding) is
    asserted by such director, officer or controlling person in
    connection with the securities being registered, the registrant
    will, unless in the opinion of its counsel the matter has been
    settled by controlling precedent, submit to a court of
    appropriate jurisdiction the question whether such
    indemnification by it is against public policy as expressed in
    the Securities Act and will be governed by the final
    adjudication of such issue.  (c)
    The undersigned registrant hereby undertakes that:  (1)
    For purposes of determining any liability under the Securities
    Act of 1933, the information omitted from the form of prospectus
    filed as part of this registration statement in reliance upon
    Rule 430A and contained in a form of prospectus filed by
    the registrant pursuant to Rule 424(b)(1) or (4) or
    497(h) under the Securities Act shall be deemed to be part of
    this registration statement as of the time it was declared
    effective; and(2)
    For the purpose of determining any liability under the
    Securities Act of 1933, each post-effective amendment that
    contains a form of prospectus shall be deemed to be a new
    registration statement relating to the securities offered
    therein, and the offering of such securities at that time shall
    be deemed to be the initial bona fide offering thereof. II-4




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##### Table of Contents



SIGNATURES
  Form S-1
   CLOVIS ONCOLOGY, INC.
  By:
    /s/  Patrick
    J. Mahaffy   Title:
    President and Chief Executive Officer  POWER OF
    ATTORNEY
    Form S-1
  Signature

Title

Date/s/  Patrick
    J. MahaffyPatrick
    J. Mahaffy

President and Chief Executive Officer; Director(Principal Executive Officer)

June 23, 2011/s/  Erle
    T. MastErle
    T. Mast

Executive Vice President and
    Chief Financial Officer(Principal Financial Officer
    and Principal Accounting Officer)

June 23, 2011/s/  Brian
    G. AtwoodBrian
    G. Atwood

Director

June 23, 2011/s/  M.
    James BarrettM.
    James Barrett

Director

June 23, 2011/s/  James
    C. BlairJames
    C. Blair

Director

June 23, 2011/s/  Paul
    KlingensteinPaul
    Klingenstein

Director

June 23, 2011 II-5




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##### Table of Contents



Signature

Title

Date/s/  Edward
    J. McKinleyEdward
    J. McKinley

Director

June 23, 2011/s/  John
    C. ReedJohn
    C. Reed

Director

June 23, 2011/s/  Thorlef
    SpickschenThorlef
    Spickschen

Director

June 23, 2011  II-6




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##### Table of Contents



INDEX TO
    EXHIBITS
  ExhibitNumber

Exhibit Description1
.1

Form of Underwriting Agreement.3
.1

Amended and Restated Certificate of Incorporation of Clovis
    Oncology, Inc., as amended, as currently in effect.3
.2

Bylaws of Clovis Oncology, Inc., as currently in effect.3
.3

Form of Amended and Restated Certificate of Incorporation of
    Clovis Oncology, Inc., to be effective upon the closing of this
    offering.3
.4

Form of Amended and Restated Bylaws of Clovis Oncology, Inc., to
    be effective upon the closing of this offering.4
.1

Form of Common Stock Certificate of Clovis Oncology, Inc.4
.2

Clovis Oncology Inc. Investor Rights Agreement, dated as of
    May 15, 2009, between Clovis Oncology, Inc., certain
    investors named therein.5
.1

Opinion of Willkie Farr & Gallagher LLP regarding the
    validity of the securities being registered.10
.1*

Amended and Restated License Agreement, dated as of
    November 10, 2010, by and between Clovis Oncology, Inc. and
    Clavis Pharma ASA.10
.2*

Amended and Restated Strategic License Agreement, dated as of
    June 16, 2011, by and between Clovis Oncology, Inc. and
    Avila Therapeutics, Inc.10
.3*

License Agreement, dated as of June 2, 2011, by and between
    Clovis Oncology, Inc. and Pfizer, Inc.10
.4+

Clovis Oncology, Inc. 2009 Equity Incentive Plan.10
.5+

Clovis Oncology, Inc. 2011 Equity Incentive Plan.10
.6+

Form of Clovis Oncology, Inc. 2009 Equity Incentive Plan Stock
    Option Agreement.10
.7+

Form of Clovis Oncology, Inc. 2011 Equity Incentive Plan Stock
    Option Agreement.10
.8+

At-Will Employment, Confidential Information, Invention
    Assignment, and Arbitration Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Patrick J. Mahaffy.10
.9+

At-Will Employment, Confidential Information, Invention
    Assignment, and Arbitration Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Erle T. Mast.10
.10+

At-Will Employment, Confidential Information, Invention
    Assignment, and Arbitration Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Gillian C. Ivers-Read.10
.11+

At-Will Employment, Confidential Information, Invention
    Assignment, and Arbitration Agreement, dated as of May 13,
    2009, between Clovis Oncology, Inc. and Andrew R. Allen.10
.12+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and John C. Reed.10
.13+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and Paul Klingenstein.10
.14+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and James C. Blair.10
.15+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and Edward J. McKinley.10
.16+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and Thorlef Spickschen.10
.17+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and M. James Barrett.10
.18+

Indemnification Agreement, dated as of May 15, 2009,
    between Clovis Oncology, Inc. and Brian G. Atwood.




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##### Table of Contents



ExhibitNumber

Exhibit Description10
.19+

Indemnification Agreement, dated as of May 12, 2009,
    between Clovis Oncology, Inc. and Patrick J. Mahaffy.10
.20+

Indemnification Agreement, dated as of May 12, 2009,
    between Clovis Oncology, Inc. and Erle T. Mast.10
.21+

Indemnification Agreement, dated as of May 12, 2009,
    between Clovis Oncology, Inc. and Gillian C. Ivers-Read.10
.22+

Indemnification Agreement, dated as of May 13, 2009,
    between Clovis Oncology, Inc. and Andrew R. Allen.10
.23+

Restricted Stock Purchase Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Patrick J. Mahaffy.10
.24+

Restricted Stock Purchase Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Erle T. Mast.10
.25+

Restricted Stock Purchase Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Gillian C. Ivers-Read.10
.26+

Restricted Stock Purchase Agreement, dated as of May 12,
    2009, between Clovis Oncology, Inc. and Andrew R. Allen.21
.1

List of Subsidiaries of Clovis Oncology, Inc.23
.1

Consent of Ernst & Young LLP.23
.2

Consent of Willkie Farr & Gallagher LLP (included in
    Exhibit 5.1).24
.1

Power of Attorney (included in the signature pages hereto).    +
    
    Indicates management contract or compensatory plan.
    
    To be filed by amendment.*
    
    Confidential treatment has been requested with respect to
    certain portions of this exhibit. Omitted portions have been
    filed separately with the Securities and Exchange Commission.