The Management's Discussion and Analysis of Financial Condition and Results of Operations contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements about our expectations related to the progress and success of our internal proprietary drug discovery activities, our ability to obtain additional capital to fund our operations and/or reduce our research and development spending, realizing new revenue streams and obtaining future out-licensing collaboration agreements that include up-front milestone and/or royalty payments, our ability to realize up-front milestone and royalty payments under our existing or any future agreements, future research and development spending, our working capital requirements and our future headcount requirements. In some cases, forward-looking statements can be identified by the use of terminology such as "may," "will," "expects," "intends," "plans," "anticipates," "estimates," "potential," or "continue," or the negative thereof or other comparable terminology. These statements are based on current expectations and projections about our industry and assumptions made by management and are not guarantees of future performance. Although we believe that the expectations reflected in the forward-looking statements contained herein are reasonable, these expectations or any of the forward-looking statements could prove to be incorrect, and actual results could differ materially from those projected or assumed in the forward-looking statements. Our future financial condition, as well as any forward-looking statements are subject to significant risks and uncertainties, including but not limited to the factors set forth under the heading "Risk Factors" in Part II, Item 1A of this Form 10-Q and Item IA of our Annual Report on Form 10-K for the fiscal year ended June 30, 2008. All forward looking statements are made as of the date hereof, and, unless required by law, we undertake no obligation to update any forward-looking statements.

The following discussion of our financial condition and results of operations should be read in conjunction with the financial statements and notes to those statements included elsewhere in this quarterly report. The terms "we," "us," "our" and similar terms refer to Array BioPharma Inc.

Overview

We are a biopharmaceutical company focused on the discovery, development and commercialization of targeted small molecule drugs to treat patients afflicted with cancer, inflammatory and metabolic diseases. Our proprietary drug development pipeline includes clinical candidates that are designed to regulate therapeutically important target proteins. In addition, leading pharmaceutical and biotechnology companies partner with us to discover and develop drug candidates across a broad range of therapeutic areas.

The eight most advanced wholly-owned programs in our development pipeline are as follows:

1. ARRY-797, a p38 inhibitor and pan-cytokine modulator for inflammation and for pain;
2. ARRY-162, a MEK inhibitor for inflammation;
3. ARRY-543, an ErbB family (EFGR / ErbB-2) inhibitor for cancer;
4. ARRY-520, a KSP inhibitor for cancer;
5. ARRY-614, a p38/Tie 2 dual inhibitor for cancer;
6. ARRY-380, an ErbB-2 inhibitor for cancer;
7. ARRY-403, a glucokinase activator for Type II diabetes; and
8. ARRY-300, a MEK inhibitor.

We also have a portfolio of drug discovery programs that we believe will continue to generate Investigational New Drug, or IND, applications each year. Our discovery efforts have also generated additional early-stage drug candidates and we may choose to out-license select promising candidates through research partnerships prior to filing an IND.

We have built our proprietary pipeline of research and development programs on an investment of $308.2 million from our inception through March 31, 2009, including $20.0 million and $68.2 million for the three and nine months ended March 31, 2009, respectively. Over the past three fiscal years, research and development expenses have significantly increased year over year to support our clinical development efforts and were $90.3 million for fiscal 2008, compared to $57.5 million for fiscal 2007 and $33.4 million for fiscal 2006.

In light of ongoing uncertainty in the financial markets, we recently announced a plan to focus our efforts on advancing our clinical programs through proof-of-concept to maximize their value and accelerate our partnering activities. In addition, we intend to scale back resources devoted to early discovery research and further focus our development efforts on our most promising candidates. Consequently, for the remainder of fiscal 2009, we currently expect that quarterly research and development expenses will remain at a level similar to the three months ended March 31, 2009.

We have received a total of $338.9 million in research funding and in up-front and milestone payments from our collaboration partners through March 31, 2009. Under our existing collaboration agreements, we have the potential to earn over $1.4 billion in additional milestone payments if we achieve all the drug discovery objectives detailed in those agreements, as well as the potential to earn royalties on any resulting product sales from 20 drug development programs.

Our significant existing collaborators include:

† Genentech, Inc., which entered into a worldwide strategic collaboration agreement with us to develop two of our cancer programs - which has been expanded to include three additional programs - all five of which are in preclinical development;
† Celgene Corporation, which entered into a worldwide strategic collaboration agreement with us focused on the discovery, development and commercialization of novel therapeutics in cancer and inflammation;
† AstraZeneca, PLC, which licensed three of our MEK inhibitors for cancer, including AZD6244 (ARRY-886), which is currently in multiple Phase 2 clinical trials.

Our fiscal year ends on June 30 each year. When we refer to a fiscal year or quarter, we are referring to the year in which the fiscal year ends and the quarters during that fiscal year. Therefore, fiscal 2008 refers to the fiscal year ended June 30, 2008 and the third quarter of fiscal 2009 refers to the quarter ended March 31, 2009.

Business Development and Collaborator Concentrations

We currently license or partner certain of our compounds and/or programs and enter into collaborations directly with pharmaceutical and biotechnology companies through opportunities identified by our business development group, senior management, scientists and customer referrals. In addition, we may license our compounds and enter into collaborations in Japan through an agent.

We had two collaborators that contributed greater than 10% of total revenue for each of the three and nine months ended March 31, 2009. There were four collaborators that contributed greater than 10% of total revenue for the three and nine months ended March 31, 2008. The revenue from these collaborators as a percentage of total revenue was as follows:

                                 Three Months Ended     Nine Months Ended
                                     March 31,              March 31,
                                  2009        2008       2009        2008

Genentech, Inc.                     70.6 %      49.9 %     66.4 %      51.3 %
Celgene Corporation                 23.7 %      18.5 %     22.0 %      12.6 %
VentiRx Pharmaceuticals, Inc.        4.5 %      13.6 %      8.7 %      16.6 %
Ono Pharmaceuticals Co., Ltd.          -        16.1 %        -        16.1 %
                                    98.8 %      98.1 %     97.1 %      96.6 %

In general, certain of our collaborators may terminate their collaboration agreements with 90 to 120 days' prior notice. Our agreement with Genentech can be terminated with 120 days' notice. Celgene may terminate its agreement with us with six months' notice.

The following table details revenue from our collaborators by region based on the country in which collaborators are located or the ship-to destination for compounds (in thousands):

                  Three Months Ended       Nine Months Ended
                      March 31,                March 31,
                   2009         2008        2009        2008

North America   $    6,005    $  6,413   $   19,111   $ 18,859
Europe                  25          51          333        182
Asia Pacific             8       1,247           30      3,681
                $    6,038    $  7,711   $   19,474   $ 22,722

All of our collaboration agreements are denominated in U.S. dollars.

Critical Accounting Policies and Estimates

Management's discussion and analysis of financial condition and results of operations are based upon our accompanying unaudited Condensed Financial Statements, which have been prepared in accordance with accounting principles generally accepted in the U.S. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses as well as the disclosure of contingent assets and liabilities. We regularly review our estimates and assumptions. These estimates and assumptions, which are based upon historical experience and on various other factors believed to be reasonable under the circumstances, form the

basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Reported amounts and disclosures may have been different had management used different estimates and assumptions or if different conditions had occurred in the periods presented.

Below is a discussion of the policies and estimates that we believe involve a high degree of judgment and complexity.

Revenue Recognition

Most of our revenue is derived from designing, creating, optimizing, evaluating and developing drug candidates for our collaborators. Our agreements with our collaboration partners include fees based on contracted annual rates for full time equivalent employees working on a project, and may also include non-refundable license and up-front fees, non-refundable milestone payments that are triggered upon achievement of specific research or development goals, and future royalties on sales of products that result from the collaboration. A small portion of our revenue comes from sales of compounds on a per-compound basis. We report revenue for lead generation and lead optimization research, process research, the development and sale of chemical compounds and the co-development of proprietary drug candidates we out-license, as Collaboration Revenue. License and Milestone Revenue is combined and reported separately from Collaboration Revenue.

Arrangements that include multiple elements are evaluated under Emerging Issues Task Force ("EITF") Issue No. 00-21, Revenue Arrangements with Multiple Deliverables ("EITF 00-21"), to determine whether the element has value to the customer on a stand-alone basis and whether reliable evidence of fair value for the delivered elements exists. Deliverables in an arrangement that do not meet the separation criteria of EITF 00-21 are treated as a single unit of accounting, generally applying applicable revenue recognition guidance for the final deliverable to the combined unit of accounting as defined in Staff Accounting Bulletin No. 104, Revenue Recognition ("SAB 104"). SAB 104 in turn established four criteria, each of which must be met, in order to recognize revenue related to the performance of services or the shipment of products. Revenue is recognized when (a) persuasive evidence of an arrangement exists,
(b) products are delivered or services are rendered, (c) the sales price is fixed or determinable, and (d) collectability is reasonably assured.

We recognize revenue from non-refundable up-front payments and license fees on a straight-line basis over the term of performance under the agreement, which is generally the research term specified in the agreement. These advance payments are deferred and recorded as Deferred Revenue upon receipt, pending recognition, and are classified as a short-term or long-term liability on our balance sheet. When the performance period is not specifically identifiable from the agreement, we estimate the performance period based upon provisions contained within the agreement, such as the duration of the research term, the specific number of full time equivalent scientists working a defined number of hours per year at a stated price under the agreement, the existence or likelihood of development commitments, and other significant commitments of ours.

We determined that the performance period applicable to our agreement with Celgene Corporation is seven years ending September 2014. We determined the performance period for our collaboration and licensing agreement with VentiRx to be one year ended in March 2008. Each of these periods coincides with the research terms specified in each licensing agreement.

Under our agreement with VentiRx, we received a non-refundable cash technology access fee and shares of preferred stock valued at $1.5 million based on the price at which such preferred stock was sold to investors in a private offering. Both the technology access fee and the value of the preferred stock were recorded as advance payments from collaborators and Deferred Revenue, and were recognized as revenue on a straight-line basis over the estimated one-year research term. The preferred stock has been recorded in Other Long-term Assets in the accompanying unaudited Condensed Balance Sheets.

Similarly to advance payments, for agreements that provide for milestone payments, a portion of each milestone payment is recognized as revenue when the specific milestone is achieved based on the

applicable percentage of the estimated research term that has elapsed to the total estimated research term.

We periodically review the expected performance periods under each of our agreements that provide for non-refundable up-front payments and license fees. To date, there has not been a significant change in an estimate or assumption of the expected period of performance that has had a material effect on the timing or amount of revenue recognized. Revenue recognition related to non-refundable license fees and up-front payments and to milestone payments could be accelerated in the event of early termination of programs.

Revenue from sales of Optimer building blocks is generally recognized as the compounds are shipped. We recognize revenue that is based on contracted annual rates for full time equivalent employees working on a project on a monthly basis as work is performed.

Cost of Revenue and Research and Development Expenses for Proprietary Drug Discovery

We incur costs in connection with performing research and development activities which consist mainly of compensation, associated fringe benefits, share-based compensation, preclinical and clinical outsourcing costs and other collaboration-related costs, including supplies, small tools, facilities, depreciation, recruiting and relocation and other direct and indirect chemical handling and laboratory support costs. We allocate these costs between Cost of Revenue and Research and Development Expenses for Proprietary Drug Discovery based upon the respective time spent on each by our scientists on development conducted for our collaborators and for our internal proprietary programs, respectively. We do not bear any risk of failure for performing these activities and the payments are not contingent on the success or failure of the research program. Accordingly, we expense these costs when incurred.

Research and Development Expenses for Proprietary Drug Discovery relate to specific proprietary programs and programs under collaboration agreements which we have concluded we are likely to retain the rights to, as well as fees paid to other entities that conduct research activities on our behalf for such programs. Cost of Revenue represents costs associated with research and development conducted for our collaborators and the cost of chemical compounds sold. Where our collaboration agreements provide for us to conduct development of drug candidates, and for which our partner has an option to obtain the right to conduct further development and to commercialize a product, we attribute a portion of our research and development costs to Cost of Revenue based on the percentage of total programs under the agreement that we conclude is likely to be selected by the partner. These costs may not be incurred equally across all programs. In addition, we continually evaluate the progress of development activities under these agreements and if events or circumstances change in future periods that management reasonably believes would make it unlikely that a collaborator would exercise an option with respect to the same percentage of programs, we will adjust the allocation accordingly.

For example, we granted Celgene an option to select up to two of four programs developed under the collaboration and have concluded that Celgene is currently likely to exercise its option with respect to two of the four programs. Accordingly, we report costs associated with the Celgene collaboration as follows: 50% to Cost of Revenue, with the remaining 50% to Research and Development Expenses for Proprietary Drug Discovery.

Investments in Marketable Securities

We have designated the marketable securities held by us as of March 31, 2009 and June 30, 2008 as available-for-sale securities. These securities are accounted for in accordance with Statement of Financial Accounting Standards ("SFAS") No. 115 Accounting for Certain Investments in Debt and Equity Securities ("SFAS 115") and SFAS No. 157 Fair Value Measurements ("SFAS 157"), which was adopted by us on July 1, 2008 and was applied prospectively beginning with the first quarter of fiscal 2009. SFAS 157 establishes a single definition of fair value and a framework for measuring fair value based on a

hierarchy that distinguishes sources of available information used in fair value measurements, and requires new disclosures of assets and liabilities measured at fair value based on their level in the hierarchy.

We have also adopted Financial Accounting Standards Board ("FASB") Staff Position ("FSP") FAS 115-2 and FAS 124-2 Recognition and Presentation of Other-Than-Temporary Impairments; FSP FAS 157-4, Determining Fair Value When the Volume and Level of Activity for the Asset or Liability Have Significantly Decreased and Indentifying Transactions That Are Not Ordinary; and FSP FAS 157-3, Determining the Fair Value of a Financial Asset When the Market for that Asset is Not Active. These statements provide additional guidance and frameworks for determining the fair value of financial assets.

Marketable securities that are readily available for use in current operations are classified as short-term available-for-sale securities and are reported as a component of current assets in the accompanying unaudited Condensed Balance Sheets. Marketable securities that are not considered available for use in current operations are classified as long-term available-for-sale securities and are reported as a component of long-term assets in the accompanying unaudited Condensed Balance Sheets.

Securities that are classified as available-for-sale are carried at fair value, including accrued interest, with temporary unrealized gains and losses reported as a component of Stockholders' Equity (Deficit) until their disposition. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization is included in Interest Income. Realized gains and losses are reported in Interest Income or Interest Expense in the accompanying unaudited Condensed Statements of Operations and Comprehensive Loss as incurred. Declines in value judged to be other-than-temporary on available-for-sale securities are reported in Impairment of Marketable Securities in the accompanying unaudited Condensed Statements of Operations and Comprehensive Loss as recognized. The cost of securities sold is based on the specific identification method.

We have concluded that our investments in ARS are not available for use in current operations due to unsuccessful auctions and therefore have reported them as a component of long-term assets in the accompanying unaudited Condensed Balance Sheets. During the fiscal year ended June 30, 2008, auctions for all of the ARS, amounting to seven securities with a par value of $32.9 million and current fair value of $13.5 million, were unsuccessful. The lack of successful auctions resulted in the interest rate on these investments increasing to LIBOR plus additional basis points as stipulated in the auction rate agreements, ranging from 200 to 350 additional basis points as of June 30, 2008, which continued through all three quarters of fiscal 2009. While we now earn a higher contractual interest rate on these investments, the investments are not currently liquid and may not be liquid at a time when we need to access these funds. We may need to access these funds and liquidate the ARS prior to the time auctions of these investments are successful or the date on which the original issuers retire these securities. In this event, we may be required to sell them in a distressed sale in a secondary market most likely for a lower amount than their current fair value.

Under SFAS 157, the fair value for these securities is defined as the price that would be received to sell the securities in an orderly transaction between market participants at the measurement date. Since there was no active market data for our ARS as of June 30, 2008, we estimated the fair values for these securities, using a discounted cash flow method under the income method approach. Under the fair value hierarchy established by SFAS 157, our ARS are measured using Level 3, or unobservable inputs, as there is no active market for the securities. The most significant unobservable inputs used in this method are estimates of the amount of time until a liquidity event will occur and the discount rate, which incorporates estimates of credit risk and a liquidity premium (discount). In determining fair value, we analyzed the underlying structure and assets of each ARS, the coupon interest rates, and the current interest rate market environment. We also considered the valuations prepared by our third party investment advisor who maintains custody of these securities and conducts the related auctions. During the first quarter of 2009, our investment advisor was no longer able to provide valuation services. Due to the inherent complexity in valuing these securities, we engaged a third-party valuation firm to perform an independent valuation of the ARS in the first, second and third quarters of fiscal 2009. While we believe that the estimates used in our fair value analysis are reasonable, a change in any of the assumptions underlying these estimates would result in different fair value estimates for the ARS and could result in additional impairment charges.

See Note 3 "Marketable Securities" in the accompanying unaudited Condensed Financial Statements for additional information about our investments in ARS as well as "Other Income (Expense)" in the Results of Operations discussion below.

Accrued Outsourcing Costs

Substantial portions of our preclinical studies and all of our clinical trials have been performed by third-party medical centers or contract research organizations, which we refer to collectively as CROs. Some CROs bill monthly for services performed, while others bill based upon milestone achievement. We accrue expenses each month for agreements involving significant costs and that bill based on milestone achievement. For preclinical studies, accruals are based upon the estimated percentage of work completed and the contract milestones remaining. For costs of clinical study activities performed by CROs, accruals are estimated based upon the estimated work completed on each study and, for clinical trial expenses, accruals are based upon the number of patients enrolled and the expected duration of the study for which they will be enrolled. We monitor patient enrollment and related activities to the extent possible through internal reviews, correspondence with the CROs, clinical site visits, and review of contractual terms. Our estimates are highly dependant upon the timeliness and accuracy of the data provided by our CROs regarding the status of each program and total program spending. We periodically evaluate our estimates to determine if adjustments are necessary or appropriate based on information we receive concerning changing circumstances, conditions or events that may affect such estimates. No material adjustments to preclinical study and clinical trial expenses have been recognized to date.

Income Taxes

We estimate our actual current tax expense together with our temporary differences resulting from differing treatment of items for tax and accounting purposes. These temporary differences result in deferred tax assets and/or liabilities. We must then assess the likelihood that our deferred tax assets will be recovered from future taxable income and to the extent that we believe that it is more likely than not

we will not recover these deferred assets, we must establish a valuation allowance against these tax assets. Significant management judgment is required in determining our provision for income taxes, our deferred tax assets and liabilities and any valuation allowance against our deferred tax assets. To the extent that we believe a valuation allowance is required, we must include and expense the tax effect of the allowance within the tax provision in our Statements of Operations and Comprehensive Loss.

Results of Operations for the Three and Nine Months Ended March 31, 2009 and 2008

Revenue

Collaboration Revenue consists of revenue for lead generation and lead optimization research, custom synthesis and process research, the development and sale of chemical compounds and the co-development of proprietary drug candidates we out-license. License and Milestone Revenue is combined and reported separately from Collaboration Revenue.

A summary of our revenue follows (amounts in thousands):

                          Three Months Ended                                     Nine Months Ended
                              March 31,             Change 2009 vs. 2008             March 31,             Change 2009 vs. 2008
                           2009         2008            $             %           2009         2008            $             %

Collaboration revenue   $    4,399    $  5,613    $      (1,214 )     (21.6 )% $   13,427    $ 16,868    $      (3,441 )     (20.4 )%
License and milestone
. . .