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UNITED STATES SECURITIES AND EXCHANGE COMMISSION
 WASHINGTON, DC 20549
 FORM 10-Q
 þ
    
    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2008
 or
 o
    
    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 FOR THE TRANSITION PERIOD FROM  TO
 Commission File Number: 001-33054
 TRUBION PHARMACEUTICALS, INC.
 (Exact name of registrant as specified in its charter)
 DELAWARE
    
    52-2385898(State or other jurisdiction of incorporation or organization)
    
    (IRS Employer Identification No.)2401 FOURTH AVENUE, SUITE 1050SEATTLE, WASHINGTON
    
    98121(Address of registrants principal executive offices)
    
    (Zip Code)
 (206) 838-0500
(Telephone number, including area code)
 N/A
(Former Name, Former Address and Former Fiscal Year, if Changed Since Last Report)
 
 þ o
  Large accelerated filer o
    
    Accelerated filer þ
    
    Non-accelerated filer o
    
    Smaller reporting company o
 o þ




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##### 



TRUBION PHARMACEUTICALS, INC.
 INDEX
 PAGE
NO.PART I. FINANCIAL INFORMATION
    
    3Item 1.
    
    Financial Statements
    
    3Balance Sheets as of March 31, 2008 and December 31, 2007
    
    3Statements of Operations for the Three Months Ended March 31, 2008 and 2007
    
    4Statements of Cash Flows for the Three Months Ended March 31, 2008 and 2007
    
    5Notes to Financial Statements
    
    6Item 2.
    
    Management's Discussion and Analysis of Financial Condition and Results of Operations
    
    9Item 3.
    
    Quantitative and Qualitative Disclosures About Market Risk
    
    18Item 4.
    
    Controls and Procedures
    
    18PART II. OTHER INFORMATION
    
    19Item 1A.
    
    Risk Factors
    
    19Item 6.
    
    Exhibits
    
    32SIGNATURES
    
    33EXHIBIT INDEXEXHIBIT 31.1EXHIBIT 31.2EXHIBIT 32.1
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PART I. FINANCIAL INFORMATION
 
 ITEM 1. FINANCIAL STATEMENTS
 TRUBION PHARMACEUTICALS, INC.
 
 BALANCE SHEETS
(In thousands, except share and par value)
 March 31, 2008
    
    
    December 31, 2007(unaudited)ASSETSCurrent assets:Cash and cash equivalents
    
    $
    19,233
    
    
    $
    41,827Investments
    
    
    52,851
    
    
    
    36,688Receivable from collaboration
    
    
    2,876
    
    
    
    4,237Prepaid expenses
    
    
    942
    
    
    
    1,224Total current assets
    
    
    75,902
    
    
    
    83,974Property and equipment, net
    
    
    10,985
    
    
    
    11,163Other assets
    
    
    27
    
    
    
    35Total assets
    
    $
    86,914
    
    
    $
    95,174LIABILITIES AND STOCKHOLDERS EQUITYCurrent liabilities:Accounts payable
    
    $
    483
    
    
    $
    1,031Accrued liabilities
    
    
    3,525
    
    
    
    3,337Accrued compensation
    
    
    1,265
    
    
    
    2,022Current portion of notes payable
    
    
    2,325
    
    
    
    2,426Current portion of deferred rent
    
    
    180
    
    
    
    180Current portion of deferred revenue
    
    
    5,848
    
    
    
    5,848Total current liabilities
    
    
    13,626
    
    
    
    14,844Non-current portion of notes payable
    
    
    7,024
    
    
    
    7,567Non-current portion of deferred rent
    
    
    270
    
    
    
    315Non-current portion of deferred revenue
    
    
    17,544
    
    
    
    19,006Interest rate swap liability
    
    
    363
    
    
    
    129Commitments and contingenciesStockholders equity :Preferred stock, $0.001 par value per share;
shares authorized  5,000,000 at March 31,
2008 and December 31, 2007; issued and
outstanding  none at March 31, 2008 and
December 31, 2007
    
    
    
    
    
    
    Common stock, $0.001 par value per share;
shares authorized  150,000,000 at March
31, 2008 and December 31, 2007; issued and
outstanding  17,834,226 at March 31, 2008
and 17,792,170 at December 31, 2007
    
    
    18
    
    
    
    18Additional paid-in capital
    
    
    121,253
    
    
    
    120,471Deferred stock-based compensation
    
    
    (189
    )
    
    
    (294
    )Accumulated other comprehensive income (loss)
    
    
    (117
    )
    
    
    28Accumulated deficit
    
    
    (72,878
    )
    
    
    (66,910
    )Total stockholders equity
    
    
    48,087
    
    
    
    53,313Total liabilities and stockholders equity
    
    $
    86,914
    
    
    $
    95,174
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TRUBION PHARMACEUTICALS, INC.
 
 STATEMENTS OF OPERATIONS
(In thousands, except per share data)
(unaudited)
 Three Months EndedMarch 31,2008
    
    
    2007Revenue:Collaboration revenue
    
    $
    3,963
    
    
    $
    4,835Operating expenses:Research and development
    
    
    7,515
    
    
    
    8,591General and administrative
    
    
    2,973
    
    
    
    2,355Total operating expenses
    
    
    10,488
    
    
    
    10,946Loss from operations
    
    
    (6,525
    )
    
    
    (6,111
    )Interest income
    
    
    735
    
    
    
    1,257Interest expense
    
    
    (178
    )
    
    
    (165
    )Net loss
    
    $
    (5,968
    )
    
    $
    (5,019
    )Basic and diluted net loss per share
    
    $
    (0.33
    )
    
    $
    (0.29
    )Shares used in computation of basic and diluted net loss per share
    
    
    17,831
    
    
    
    17,566
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TRUBION PHARMACEUTICALS, INC.
 
 STATEMENTS OF CASH FLOWS
(In thousands)
(unaudited)
 Three Months EndedMarch 31,2008
    
    
    2007Operating activities:Net loss
    
    $
    (5,968
    )
    
    $
    (5,019
    )Adjustments to reconcile net loss to net cash used in operating activities:Non-cash stock-based compensation expense
    
    
    862
    
    
    
    803Net amortization of discount on investments
    
    
    (139
    )
    
    
    (186
    )Depreciation and amortization expense
    
    
    810
    
    
    
    671Amortization of debt discount
    
    
    4
    
    
    
    6Changes in operating assets and liabilities:Receivable from collaboration
    
    
    1,361
    
    
    
    911Prepaid expenses and other assets
    
    
    290
    
    
    
    37Accounts payable
    
    
    (548
    )
    
    
    (639
    )Accrued liabilities and compensation
    
    
    (569
    )
    
    
    (1,159
    )Deferred revenue
    
    
    (1,462
    )
    
    
    (2,000
    )Deferred rent
    
    
    (45
    )
    
    
    (45
    )Net cash used in operating activities
    
    
    (5,404
    )
    
    
    (6,620
    )Investing activities:Purchases of property and equipment
    
    
    (632
    )
    
    
    (2,263
    )Purchases of investments
    
    
    (29,021
    )
    
    
    (10,017
    )Maturities of investments
    
    
    13,086
    
    
    
    16,183Net cash provided by (used in) investing activities
    
    
    (16,567
    )
    
    
    3,903Financing activities:Proceeds from issuance of notes payable
    
    
    
    
    
    
    1,516Payments on notes payable
    
    
    (648
    )
    
    
    (236
    )Proceeds from exercise of stock options
    
    
    25
    
    
    
    26Net cash provided by (used in) financing activities
    
    
    (623
    )
    
    
    1,306Net decrease in cash and cash equivalents
    
    
    (22,594
    )
    
    
    (1,411
    )Cash and cash equivalents at beginning of period
    
    
    41,827
    
    
    
    56,414Cash and cash equivalents at end of period
    
    $
    19,233
    
    
    $
    55,003Supplemental disclosure information:Cash paid for interest
    
    $
    140
    
    
    $
    158
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TRUBION PHARMACEUTICALS, INC.
 
 NOTES TO FINANCIAL STATEMENTS
(unaudited)
 1. Summary of Significant Accounting Policies
 Basis of Presentation
   Use of Estimates
  Reclassifications
  Adoption of Standards
 Fair Value Measurements,
 The Fair Value Option for Financial Assets and
Financial Liabilities,
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Accounting for Nonrefundable Advance Payments for Goods or Services Received for Use in
Future Research and Development Activities
 2. Fair Value Measurements
      Level 1
    
    
    Level 2
    
    
    Level 3
    
    
    TotalAssets:Money market funds
    
    $
    15,586
    
    
    $
    
    
    
    $
    
    
    
    $
    15,586U.S. Treasury securities
    
    
    1,249
    
    
    
    
    
    
    
    
    
    
    
    1,249Corporate debt securities
    
    
    
    
    
    
    54,848
    
    
    
    
    
    
    
    54,848Total
    
    $
    16,835
    
    
    $
    54,848
    
    
    $
    
    
    
    $
    71,683Liabilities:Interest rate swap
    
    
    
    
    
    
    363
    
    
    
    
    
    
    
    363Total
    
    $
    
    
    
    $
    363
    
    
    $
    
    
    
    $
    363
   3. Net Loss per Share
  As of March 31,2008
    
    2007Stock options
    
    
    2,115
    
    
    
    1,588Common shares subject to repurchase
    
    
    
    
    
    
    12,115
    
    
    
    1,589
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4. Collaboration Agreement
     8




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5. Property and Equipment
  March 31,
    
    
    December 31,2008
    
    
    2007Lab equipment
    
    $
    9,964
    
    
    $
    8,874Leasehold improvements
    
    
    6,607
    
    
    
    6,528Computer equipment and software
    
    
    1,045
    
    
    
    990Furniture and fixtures
    
    
    447
    
    
    
    447Construction in progress
    
    
    46
    
    
    
    63818,109
    
    
    
    17,477Accumulated depreciation and amortization
    
    
    (7,124
    )
    
    
    (6,314
    )$
    10,985
    
    
    $
    11,163
 6. Accrued Liabilities
  March 31,
    
    
    December 31,2008
    
    
    2007Accrued clinical trials
    
    $
    1,773
    
    
    $
    1,553Accrued professional fees
    
    
    1,194
    
    
    
    941Other
    
    
    558
    
    
    
    843$
    3,525
    
    
    $
    3,337
 7. Comprehensive Income (Loss)
  Three
months ended March 31,2008
    
    
    2007Net loss
    
    $
    (5,968
    )
    
    $
    (5,019
    )Net unrealized gains (losses) on
securities available-for-sale
    
    
    89
    
    
    
    (8
    )Net unrealized losses on cash flow hedges
    
    
    (234
    )
    
    
    Comprehensive loss
    
    $
    (6,113
    )
    
    $
    (5,027
    )
 8. Commitments
  
 ITEM 2.
    
    MANAGEMENTS DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 This quarterly report on Form 10-Q contains forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange
Act of 1934, as amended, which are subject to the safe harbor created by those sections.
Forward-looking statements are based on our managements beliefs and assumptions and on information
currently available to them. In some cases you can identify forward-looking statements by terms
such as may, will, should, could, would, expect, plans, anticipates, believes,
estimates, projects, predicts, potential, and similar expressions intended to identify
forward-looking statements. Examples of these statements include, but are not limited to,
statements regarding: the implications of interim or final results of our
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clinical trials, the progress of our research programs, including clinical testing, the extent
to which our issued and pending patents may protect our products and technology, our ability to
identify new product candidates, the potential of such product candidates to lead to the
development of commercial products, our anticipated timing for initiation or completion of our
clinical trials for any of our product candidates, our future operating expenses, our future
losses, our future expenditures for research and development, and the sufficiency of our cash
resources. Our actual results could differ materially from those anticipated in these
forward-looking statements for many reasons, including the risks faced by us and described in Part
II, Item 1A of this quarterly report on Form 10-Q and our other filings with the SEC. You should
not place undue reliance on these forward-looking statements, which apply only as of the date of
this quarterly report on Form 10-Q . You should read this quarterly report on Form 10-Q completely
and with the understanding that our actual future results may be materially different from what we
expect. Except as required by law, we assume no obligation to update these forward-looking
statements, whether as a result of new information, future events, or otherwise.
 The following discussion and analysis should be read in conjunction with the unaudited
financial statements and notes thereto included in Part I, Item 1 of this quarterly report on Form
10-Q.
 Overview
 tm
  tm
   10




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Critical Accounting Policies and Significant Judgments and Estimates
   11




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Revenue Recognition
   Up-Front Fees and License Fees:
 Collaborative Research Funding:
 Milestones:
 Royalties:
 Preclinical Study, Clinical Trial, and Manufacturing Accruals
 Accounting for Research and Development Costs Accounting for
Nonrefundable Advance Payments for Goods or Services to Be Used in Future Research and Development
Activities
 12




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
    
    fees paid to contract research organizations in connection with preclinical studies;
    
    fees paid to clinical research organizations and other clinical sites in connection with clinical trials; and
    
    fees paid to contract manufacturers in connection with the production of components and drug materials for
preclinical studies and clinical trials.
  Stock-Based Compensation
 Share-Based
Payment Accounting for Stock Issued
to Employees Accounting for Certain Transactions Involving Stock Compensation, an
Interpretation of APB 25 Accounting for Stock-Based Compensation, Accounting for
Stock-Based Compensation  Transition and Disclosure.
  13




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Three months ended
    
    Three months endedMarch 31, 2008
    
    March 31, 2007Risk-free interest rate
    
    
    2.80
    %
    
    
    4.62
    %Weighted-average expected life (in years)
    
    
    6.03
    
    
    
    6.25Expected dividend yield
    
    
    0
    %
    
    
    0
    %Expected volatility rate
    
    
    70
    %
    
    
    75
    %Weighted-average estimated fair value of employee options
    
    $
    5.71
    
    
    $
    14.34
   Results of Operations for the Three Months Ended March 31, 2008 and 2007
 Revenue
  Research and Development Expenses
   14




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Three months endedMarch 31,2008
    
    
    2007Research and preclinical programs
    
    $
    5,020
    
    
    $
    4,869Clinical development programs
    
    
    2,495
    
    
    
    3,722Total research and development
    
    $
    7,515
    
    
    $
    8,591
    General and Administrative Expenses
  Net Interest Income
  15




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Liquidity and Capital Resources
   Operating Activities:
 Investing Activities:
 Financing Activities:
   16




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
    
    expenditures related to continued preclinical and clinical development of our product candidates
during this period will be within budgeted levels;
    
    unexpected costs related to the development of our manufacturing capability will not be material; and
    
    the hiring of a number of new employees at salary levels consistent with our estimates to support
our continued growth during this period.
  
    
    milestone payments projected to be received under the Wyeth collaboration agreement;
    
    the scope, rate of progress, results and costs of our preclinical testing, clinical trials, and
other research and development activities;
    
    the terms and timing of any additional collaborative or licensing agreements that we may establish;
    
    the number and characteristics of product candidates that we pursue;
    
    the cost of preparing, filing, prosecuting, defending, and enforcing any patent claims and other
intellectual property rights;
    
    the hiring of a number of new employees will be at salary levels consistent with our estimates to support our continued growth during this period;
    
    the cost of establishing clinical and commercial supplies of our product candidates;
    
    the cost, timing, and outcomes of regulatory approvals; and
    
    the extent to which we acquire or invest in businesses, products, or technologies.
   17




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ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
   
 ITEM 4. CONTROLS AND PROCEDURES
 Evaluation of disclosure controls and procedures.
 Changes in internal control over financial reporting.
 18




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PART II. OTHER INFORMATION
 
 Item 1A. Risk Factors
  Risks Related to Our Business
 Our success depends on the success of our lead product candidate, TRU-015, and we cannot be certain
that it will be safe or effective, complete clinical trials, receive regulatory approval, or be
successfully commercialized.
  We depend on our collaborative relationship with Wyeth to develop, manufacture, and commercialize
our lead product candidate,
TRU-015, and other selected product candidates.
   19




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We cannot assure you any of our product candidates will be safe or effective, or receive regulatory
approval.
  We have incurred operating losses in each year since our inception and expect to continue to incur
substantial and increasing losses for the foreseeable future.
  20




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If we fail to obtain the capital necessary to fund our operations, we may be unable to develop our
product candidates and we could be forced to share our rights to these product candidates with
third parties on terms that may not be favorable to us.
   Any failure or delay in commencing or completing clinical trials for product candidates could
severely harm our business.
  
    
    our or our collaborators ability to obtain regulatory approval to commence a clinical trial;
    
    our or our collaborators ability to manufacture or obtain from third parties materials sufficient for use in
preclinical studies and clinical trials;
    
    delays in patient enrollment and variability in the number and types of patients available for clinical trials;
    
    poor effectiveness of product candidates during clinical trials;
    
    unforeseen safety issues or side effects;
    
    governmental or regulatory delays and changes in regulatory requirements, policy, and guidelines; and
    
    varying interpretation of data by us, any or all of our collaborators, the FDA, and similar foreign regulatory
agencies.
  21




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If our SMIP tm technology or our product candidates, including TRU-015, conflict
with the rights of others, including Genentech intellectual property rights of which we are aware,
we may not be able to manufacture or market our product candidates, which could have a material
adverse effect on us and on our collaboration agreement with Wyeth.
    tm
  22




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If we are unable to obtain, maintain, and enforce our proprietary rights, we may not be able to
compete effectively or operate profitably.
  
    
    obtain and maintain patent and other proprietary protection for our technology, processes, and product candidates;
    
    enforce patents once issued and defend those patents if their enforceability is challenged;
    
    preserve trade secrets; and
    
    operate without infringing the patents and proprietary rights of third parties.
  
    
    we might not have been the first to make the inventions covered by any of our patents, if issued, or our
pending patent applications;
    
    we might not have been the first to file patent applications for these inventions;
    
    others may independently develop similar or alternative technologies or duplicate any of our technologies;
    
    it is possible that none of our pending patent applications will result in issued patents or, if issued,
these patents may not be sufficient to protect our technology or provide us with a basis for commercially
viable products, and may not provide us with any competitive advantages;
    
    if our pending applications issue as patents, they may be challenged by third parties as not infringed,
invalid, or unenforceable under U.S. or foreign laws;
    
    if issued, the patents under which we hold rights may not be valid or enforceable; or
    
    we may develop additional proprietary technologies that are not patentable and that may not be adequately
protected through trade secrets, if, for example, a competitor were to independently develop duplicative,
similar, or alternative technologies.
   23




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We rely on third parties to conduct our clinical trials. If these third parties do not perform as
contractually required or otherwise expected, we may not be able to obtain regulatory approval for
or commercialize our product candidates.
  We currently rely on third-party manufacturers to supply our product candidates and will rely on
third-party manufacturers to manufacture our product candidates in commercial quantities, which
could delay or prevent the clinical development and commercialization of our product candidates.
   24




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If we enter into additional strategic partnerships, such as our relationship with Wyeth, we may be
required to relinquish important rights to and control over the development of our product
candidates or otherwise be subject to terms unfavorable to us.
  
    
    we may not be able to control the amount and timing of resources that
our strategic partners devote to the development or commercialization
of product candidates;
    
    strategic partners may delay clinical trials, provide insufficient
funding, terminate a clinical trial or abandon a product candidate,
repeat or conduct new clinical trials, or require a new version of a
product candidate for clinical testing;
    
    strategic partners may not pursue further development and
commercialization of products resulting from the strategic partnering
arrangement or may elect to discontinue research and development
programs;
    
    strategic partners may not commit adequate resources to the marketing
and distribution of any future products, limiting our potential
revenues from these products;
    
    disputes may arise between us and our strategic partners that result
in the delay or termination of the research, development, or
commercialization of our product candidates or that result in costly
litigation or arbitration that diverts managements attention and
consumes resources;
    
    strategic partners may experience financial difficulties;
    
    strategic partners may not properly maintain or defend our
intellectual property rights or may use our proprietary information in
a manner that could jeopardize or invalidate our proprietary
information or expose us to potential litigation;
    
    business combinations or significant changes in a strategic partners
business strategy may also adversely affect a strategic partners
willingness or ability to complete its obligations under any
arrangement;
    
    strategic partners could independently move forward with a competing
product candidate developed either independently or in collaboration
with others, including our competitors; and
    
    strategic partners could terminate the arrangement or allow it to
expire, which would delay the development and may increase the cost of
developing our product candidates.
 Our relationship with Wyeth may have a negative effect on our ability to enter into beneficial
relationships with third parties.
  25




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Even if our product candidates receive regulatory approval, they could be subject to restrictions
or withdrawal from the market and we may be subject to penalties if we fail to comply with
regulatory requirements or if we experience unanticipated problems with our products.
  
    
    restrictions on the products or manufacturing processes;
    
    withdrawal of the products from the market;
    
    voluntary or mandatory recalls;
    
    fines;
    
    suspension of regulatory approvals;
    
    product seizures; or
    
    injunctions or the imposition of civil or criminal penalties.
  Our product candidates may never achieve market acceptance even if we obtain regulatory approvals.
  
    
    our ability to provide acceptable evidence of safety and efficacy;
    
    the prevalence and severity of adverse side effects;
    
    availability, relative cost, and relative efficacy of alternative and competing treatments;
    
    the effectiveness of our marketing and distribution strategy;
    
    publicity concerning our products or competing products and treatments; and
    
    our ability to obtain sufficient third-party insurance coverage or reimbursement.
 26




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Failure to obtain regulatory approval in foreign jurisdictions would prevent us from marketing our
products internationally.
  We may incur substantial costs as a result of litigation or other proceedings relating to patent
and other intellectual property rights.
  If any products we develop become subject to unfavorable pricing regulations, third-party
reimbursement practices, or healthcare reform initiatives, our business could be harmed.
  We face potential product liability exposure, and if successful claims are brought against us, we
may incur substantial liability for a product candidate and may have to limit its
commercialization.
  27




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
    
    decreased demand for our product candidates;
    
    impairment of our business reputation;
    
    withdrawal of clinical trial participants;
    
    costs of related litigation;
    
    substantial monetary awards to patients or other claimants;
    
    loss of revenues; and
    
    the inability to commercialize our product candidates.
  We face substantial competition, which may result in others discovering, developing, or
commercializing products before, or more successfully, than we do.
  Product Candidates for Autoimmune and Inflammatory Diseases. ® ® ® ® ®
 Product Candidates for Systemic Lupus Erythematosus.
 Product Candidates for B-cell Malignancies. ® ® ® ® ®
  
    
    design and develop products that are superior to other products in the market;
    
    attract and retain qualified scientific, medical, product development, commercial and sales and marketing
personnel;
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
    
    obtain patent and/or other proprietary protection for our processes, product candidates, and technologies;
    
    operate without infringing the patents and proprietary rights of third parties;
    
    obtain required regulatory approvals; and
    
    successfully collaborate with others in the design, development, and commercialization of new products.
  If we are unable to establish a sales and marketing infrastructure or enter into collaborations
with partners to perform these functions, we will not be able to commercialize our product
candidates.
  
    
    our inability to recruit and retain adequate numbers of effective sales and marketing personnel;
    
    the inability of sales personnel to obtain access to or persuade adequate numbers of physicians
to prescribe our products;
    
    the lack of complementary products to be offered by sales personnel, which may put us at a
competitive disadvantage relative to companies with more extensive product lines; and
    
    unforeseen costs and expenses associated with creating a sales and marketing organization.
  We rely on highly skilled personnel, and if we are unable to retain or motivate key personnel or
hire qualified personnel, we may not be able to maintain our operations or grow effectively.
  We may fail to select or capitalize on the most scientifically, clinically, or commercially
promising or profitable product candidates.
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If we use biological and hazardous materials in a manner that causes contamination or injury or
violates laws, we may be liable for damages.
  Risks Related to Our Common Stock
 The trading price of our common stock may be subject to significant fluctuations and volatility,
and our stockholders may be unable to resell their shares at a profit.
  
    
    our ability to develop and market new and enhanced product candidates on a timely basis;
    
    announcements by us or our collaborators or competitors of new commercial products,
clinical progress or the lack thereof, changes in or terminations of relationships,
significant contracts, commercial relationships, or capital commitments;
    
    commencement of, or our involvement in, litigation;
    
    changes in earnings estimates or recommendations by securities analysts;
    
    changes in governmental regulations or in the status of our regulatory approvals;
    
    any major change in our board or management;
    
    quarterly variations in our operating results or those of our collaborators or competitors;
    
    general economic conditions and slow or negative growth of our markets; and
    
    political instability, natural disasters, war, and/or events of terrorism.
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If securities analysts do not publish research or reports about our business, or if they downgrade
our stock, the price of our stock could decline.
  The concentration of our capital stock ownership with insiders will likely limit your ability to
influence corporate matters.
  Anti-takeover provisions in our charter documents and under Delaware law could make an acquisition
of us, which may be beneficial to our stockholders, more difficult and may prevent attempts by our
stockholders to replace or remove our current management.
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ITEM 6. EXHIBITS
 ExhibitNumber
    
    Description3.1
    
    Amended and Restated Certificate of Incorporation (Exhibit 3.1)(A)3.2
    
    Amended and Restated Bylaws (Exhibit 3.2)(A)3.3
    
    Amendment to Amended and Restated Bylaws (Exhibit 3.1)(B)4.1
    
    Form of common stock certificate (Exhibit 4.1)(C)4.2
    
    Amended and Restated Investor Rights Agreement, dated July 13, 2004 (Exhibit 4.2)(A)4.3
    
    Amendment No. 1 to Amended and Restated Investor Rights Agreement, dated December 19, 2005
(Exhibit 4.3)(A)10.1
    
    Employment Agreement, dated as of March 21, 2008, between Trubion Pharmaceuticals, Inc. and Peter
A. Thompson (Exhibit 10.1)(D)10.2
    
    Employment Agreement, dated as of March 21, 2008, between Trubion Pharmaceuticals, Inc. and
Michelle G. Burris (Exhibit 10.2)(D)10.3
    
    Employment Agreement, dated as of March 21, 2008, between Trubion Pharmaceuticals, Inc. and
Daniel J. Burge (Exhibit 10.3)(D)10.4
    
    Employment Agreement, dated as of March 21, 2008, between Trubion Pharmaceuticals, Inc. and
Kathleen McKereghan Deeley (Exhibit 10.4)(D)10.5
    
    Employment Agreement, dated as of March 21, 2008, between Trubion Pharmaceuticals, Inc. and
Kendall M. Mohler, Ph.D. (Exhibit 10.5)(D)10.6
    
    Form of Amendment No. 1 to Employment Agreement between Trubion Pharmaceuticals, Inc. and
Executive (Exhibit 10.1)(E)31.1*
    
    Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 200231.2*
    
    Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 200232.1*
    
    Certification of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C § 1350
as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
 
 (A)
    
    Incorporated by reference to the designated exhibit to the
registrants Registration Statement on Form S-1 filed with the SEC on
June 2, 2006 (File No. 333-134709).(B)
    
    Incorporated by reference to the designated exhibit to the
registrants Current Report on Form 8-K filed with the SEC on April 4,
2007 (File No. 001-33054).(C)
    
    Incorporated by reference to the designated exhibit to the
registrants Registration Statement on Form S-1 filed with the SEC on
October 2, 2006 (File No. 333-134709).(D)
    
    Incorporated by reference to the designated exhibit to the
registrants Current Report on Form 8-K (File No. 001-33054) filed
with the SEC on March 25, 2008.(E)
    
    Incorporated by reference to the designated exhibit to the
registrants Current Report on Form 8-K (File No. 001-33054) filed
with the SEC on April 8, 2008.*
    
    Filed herewith. 32




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SIGNATURES
   TRUBION PHARMACEUTICALS, INC.By:
    
    /s/ Michelle G. BurrisMichelle G. BurrisSenior Vice President andChief Financial Officer(Principal Accounting and Financial Officer)
 33