UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2008

OR

FOR THE TRANSITION PERIOD FROM             TO

Commission File Number 0-29889

Rigel Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

(650) 624-1100

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes  x  No  o

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes  o  No  x

As of May 1, 2008, there were 36,481,084 shares of the registrant’s common stock outstanding.

RIGEL PHARMACEUTICALS, INC.
QUARTERLY REPORT ON FORM 10-Q
FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2008

INDEX

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PART I  FINANCIAL INFORMATION

Item 1.    Condensed Financial Statements

RIGEL PHARMACEUTICALS, INC.

CONDENSED BALANCE SHEETS

(in thousands, except share and per share amounts)

(1)   The balance sheet at December 31, 2007 has been derived from the audited financial statements at that date included in Rigel’s Annual Report on Form 10-K for the year ended December 31, 2007.

See accompanying notes.

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RIGEL PHARMACEUTICALS, INC.

CONDENSED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

(unaudited)

See accompanying notes.

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RIGEL PHARMACEUTICALS, INC.

STATEMENTS OF CASH FLOWS

(In thousands)

(unaudited)

See accompanying notes.

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Rigel Pharmaceuticals, Inc.

Notes to Condensed Financial Statements

(unaudited)

In this report, “Rigel,” “we,” “us” and “our” refer to Rigel Pharmaceuticals, Inc.

1. Nature of Operations

We were incorporated in the state of Delaware on June 14, 1996. We are engaged in the discovery and development of novel, small-molecule drugs for the treatment of inflammatory diseases and cancer, as well as viral and metabolic diseases.

2. Basis of Presentation

Our accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and pursuant to the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by generally accepted accounting principles for complete financial statements. These unaudited condensed financial statements include all normal and recurring adjustments that we believe are necessary to fairly state our financial position and the results of our operations and cash flows. Interim-period results are not necessarily indicative of results of operations or cash flows for a full-year. The balance sheet at December 31, 2007 has been derived from audited financial statements at that date, but does not include all disclosures required by U.S. generally accepted accounting principles for complete financial statements. Because all of the disclosures required by U.S. generally accepted accounting principles for complete financial statements are not included herein, these unaudited interim condensed financial statements and the notes accompanying them should be read in conjunction with our audited financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2007.

The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances. Actual results could differ from these estimates.

3. Recent Accounting Pronouncements

On December 12, 2007, the Financial Accounting Standards Board, or FASB, ratified the consensus reached by the Emerging Issues Task Force, or EITF, on EITF Issue No. 07-1. “Accounting for Collaborative Arrangements,” or EITF 07-1. EITF 07-1 defines collaborative arrangements and establishes reporting requirements for transactions between participants in a collaborative arrangement and between participants in the arrangement and third parties. EITF 07-1 is effective for financial statements issued for fiscal years beginning after December 15, 2008. We are currently evaluating the impact of adopting EITF 07-1 on our financial statements and cannot estimate the impact of adoption at this time.

On June 27, 2007, the FASB ratified the consensus reached by the EITF on EITF Issue No. 07-3, “Accounting for Advance Payments for Goods or Services to Be Used in Future Research and Development Activities,” or EITF 07-3. EITF 07-3 requires companies to defer and capitalize prepaid, nonrefundable research and development payments to third parties, and amortize them over the period that the research and development activities are performed or the services are provided, subject to an assessment of recoverability. EITF 07-3 is effective for new contracts entered into during fiscal years beginning after December 15, 2007, including interim periods within those fiscal years. The adoption of EITF 07-3 did not have a material affect on our financial statements.

In September 2006, the FASB issued Statement of Financial Accounting Standards No 157, “Fair Value Measurements,” or SFAS 157. This standard defines fair value, establishes a framework for measuring fair value under generally accepted accounting principles, and expands disclosures about fair value measurements. SFAS 157 is effective for financial statements issued for fiscal years beginning after November 15, 2007, except that under FASB Staff Position 157-2, “Effective Date of FASB Statement No. 157,” companies are allowed to delay the effective date of SFAS 157 for non-financial assets and non-financial liabilities that are not recognized or disclosed at fair value on a recurring basis until fiscal years beginning after November 15, 2008. We have adopted SFAS 157 with regard to all financial assets and liabilities for our financial statements going forward, and have elected to delay the adoption of SFAS 157 for non-financial assets and non-financial liabilities for one year.  For further discussion of SFAS 157, see Note 8 to these Condensed Financial Statements.

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In February 2007, the FASB issued SFAS No. 159, “The Fair Value Option for Financial Assets and Financial Liabilities—Including an amendment of FASB Statement No. 115,” or SFAS 159. SFAS 159 permits entities to choose to measure many financial instruments and certain other items at fair value. Entities that elect the fair value option will report unrealized gains and losses in earnings at each subsequent reporting date. The fair value option may be elected on an instrument-by-instrument basis, with few exceptions. SFAS 159 also establishes presentation and disclosure requirements to facilitate comparisons between companies that choose different measurement attributes for similar assets and liabilities. Companies may elect the fair value option under SFAS 159 for fiscal years beginning after November 15, 2007. We elected not to adopt the fair value option of SFAS 159 at this time.

4. Basic and Diluted Net Loss Per Share

Basic and diluted net loss per share was computed by dividing the net loss for the period by the weighted average number of shares of common stock outstanding during the period. The calculation of diluted net loss per share excluded shares of potential common stock, consisting of stock options and warrants, because their effect would have been anti-dilutive.

5. Stock Award Plans

Total stock-based compensation expense related to all of our share-based awards that we recognized for the three months ended March 31, 2008 and 2007 is comprised as follows (in thousands):

Under SFAS 123(R), the fair value of each option award is estimated on the date of grant using the Black-Scholes option pricing model. We have segregated option awards into three homogenous groups, officers and directors, all other employees, and consultants, for purposes of determining fair values of options.

We determined weighted-average valuation assumptions separately for each of these groups as follows:

·                  Volatility - We estimated volatility using the historical share price performance over the expected life of the option up to the point where we have historical market data. As our options are not actively traded, implied volatility was not representative of our current volatility. We also considered other factors, such as our current clinical trials and other company activities that may affect the volatility of our stock in the future, but determined that at this time historical volatility is more indicative of our expected future stock performance.

·                  Expected term - We worked with various historical data to determine the most applicable expected term for each option group. These data included: (1) for options exercised, term of the options from option grant date to exercise date; (2) for options cancelled, term of the options from grant date to cancellation date, excluding unvested option forfeitures; and (3) for options which remained outstanding at the balance sheet date, term of the options from grant date to the end of the reporting period, and the estimated remaining term of the options. The consideration and calculation of the above data gave us reasonable estimates of the expected term for each option group. We also considered the vesting schedules of the options granted and factors surrounding exercise behavior of our groups, our current market price and company activity that may affect our market price. In addition, we also considered the vesting schedules of the options, the optionee type (i.e., officers and directors, all other employees and consultants) and other factors that may affect the expected term of the option. For options granted to consultants, we use the contractual term of the option, which is generally ten years, for the initial valuation of the option and the remaining contractual term of the option for the succeeding years.

·                  Risk-free interest rate - The risk-free interest rate is based on U.S. Treasury constant maturity rates with similar terms to the expected term of the options for each option group.

·                  Forfeiture rate - We estimated the forfeiture rate using our historical experience with pre-vesting options. We review our forfeiture rates each quarter and make changes as factors affecting our forfeiture rate calculations and assumptions change.

·                  Dividend yield - The expected dividend yield is 0% as we have not paid and do not expect to pay dividends.

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The following table summarizes the weighted-average assumptions relating to options granted for the three months ended March 31, 2008 and 2007:

Option exercise prices are set at not less than the closing price of our common stock on the trading day immediately preceding the date of grant, become exercisable at varying dates and generally expire ten years from the date of grant. We granted options to purchase 1,305,691 shares of common stock in the three months ended March 31, 2008, with a grant-date weighted average fair value of $18.48 per share. We granted options to purchase 887,087 shares of common stock during the three months ended March 31, 2007 with a grant-date weighted average fair value of $7.10 per share.  At March 31, 2008, options to purchase 1,205,465 shares of common stock were available for future grant under our stock option plans.

Employee Stock Purchase Plan (ESPP)

The fair value of awards granted under our ESPP is estimated on the date of grant using the Black-Scholes option pricing model, which uses the weighted-average assumptions set forth in the table below. Our ESPP provides for a twenty-four month offering period comprised of four six-month purchase periods with a look-back option. A look-back option is a provision in our ESPP where eligible employees can purchase shares of our common stock at a price per share equal to the lesser of 85% of the fair market value on the first day of the offering period or 85% of the fair market value on the purchase date. The plan also includes a feature that provides for a new offering period to begin when the fair market value of our common stock on any purchase date during an offering period falls below the fair market value of our common stock on the first day of such offering period.  Participants are automatically enrolled in the new offering. Expected volatilities are based on historical volatility of our stock. Expected term represents the purchase periods within our offering period. The risk-free rate for periods within the expected life is based on U.S. Treasury constant maturity rates. Stock-based compensation expense relating to our ESPP is recognized according to the FASB Technical Bulletin No. 97-1, “Accounting under Statement 123 for Certain Employee Stock Purchase Plans with a Look-back Option,” or FTB 97-1. As of March 31, 2008, there were approximately 1,510,200 shares in reserve for future issuance under the ESPP. The following table summarizes the weighted-average assumptions relating to our ESPP for the three months ended March 31, 2008 and 2007:

6. Revenue Recognition

We recognize revenue from our contract arrangements. Our revenue arrangements with multiple elements are evaluated under EITF No. 00-21, “Revenue Arrangements with Multiple Deliverables,” and are divided into separate units of accounting if certain criteria are met, including whether the delivered element has stand-alone value to the customer and whether there is objective and reliable evidence of the fair value of the undelivered items. The consideration we receive is allocated among the separate units based on their respective fair values, and the applicable revenue recognition criteria are applied to each of the separate units. Advance payments received in excess of amounts earned are classified as deferred revenue until earned.

Non-refundable, up-front payments received in connection with research and development collaboration agreements, including technology access fees, are deferred and recognized on a straight-line basis over the relevant periods of continuing involvement, generally the research term. When a research term is not specified, we estimate the time it will take us to complete our deliverables under the contract and recognize the upfront fee using the straight-line method over that time period. We review our estimates every quarter for reasonableness.

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Revenue related to collaborative research with our corporate collaborators is recognized as research services are performed over the related development funding periods for each contract. Under these agreements, we are required to perform research and development activities as specified in the applicable agreement. The payments received are not refundable and are generally based on a contractual cost per full-time equivalent employee working on the project. Research and development expenses under the collaborative research agreements, except for the Merck collaboration signed in November 2004 related to ubiquitin ligases, approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. For the Merck collaboration, we recognized a pro-rata portion of the invoiced amounts for funding of our research scientists based on the headcount dedicated to the project for the quarter. When the research portion of the collaboration ended in May 2007, we recognized the full amount of the deferred revenue related to the contract because we had no further obligations. It is our policy to recognize revenue based on our level of effort expended, and that revenue recognized will not exceed amounts billable under the arrangement.

Revenue associated with at-risk milestones pursuant to collaborative agreements is recognized based upon the achievement of the milestones as set forth in the applicable agreement.

7. Cash, Cash Equivalents and Available-For-Sale Securities

Cash, cash equivalents and available-for-sale securities consisted of the following (in thousands):

Cash equivalents and available-for-sale securities included the following securities with unrealized gains and losses (in thousands):

Available-for-sale Securities.  At March 31, 2008, the above available-for-sale securities had a weighted average maturity of approximately 139 days.

We had $761,000 in government-sponsored enterprise securities at fair values with de minimus gross unrealized losses at March 31,2008.

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8. Fair Value

In September of 2006, the FASB issued Statement No. 157, Fair Value Measurements, or SFAS 157.  SFAS 157 establishes a standard framework for measuring fair value in generally accepted accounting principles (GAAP), clarifies the definition of “fair value” within that framework, and expands disclosures about the use of fair value measurements.  We have adopted SFAS 157 with regard to all financial assets and liabilities in our financial statements going forward, and, consistent with FASB Staff Position 157-2, “Effective Date of FASB Statement No. 157,” we have elected to delay the adoption of SFAS 157 for non-financial assets and liabilities for one year.  We have no financial liabilities recorded at fair value.  Financial assets recorded at fair value are discussed below.  The adoption of SFAS 157 had no material impact to our financial statements.

Fair value is defined as the price at which an asset could be exchanged or a liability transferred (an exit price) in an orderly transaction between knowledgeable, willing parties in the principal or most advantageous market for the asset or liability. Where available, fair value is based on observable market prices or parameters or derived from such prices or parameters. Where observable prices or inputs are not available, valuation models are applied.

Financial assets recorded at fair value in the Condensed Financial Statements are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels, defined by SFAS 157 and directly related to the amount of subjectivity associated with the inputs to fair valuation of these assets and liabilities, are as follows:

Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets at the reporting date.  Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

The fair valued assets we hold that are generally included in this category are money market securities where fair value is based on publicly quoted prices.

Level 2 — Inputs are other than quoted prices included in Level 1, which are either directly or indirectly observable for the asset or liability through correlation with market data at the reporting date and for the duration of the instrument’s anticipated life.

The fair valued assets we hold that are generally included in this category are government sponsored enterprise securities, U.S. Treasury securities, corporate bonds and commercial paper where fair value is based on valuation methodologies such as models using observable market inputs, such as benchmark yields, reported trades, broker/dealer quotes, bids, offers and other reference data.

Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities and which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the reporting date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

We carry no investments classified as Level 3.

Fair Value on a Recurring Basis

Financial assets measured at fair value on a recurring basis are categorized in the tables below based upon the lowest level of significant input to the valuations:

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9. Equipment Lease Line

In January 2008, we obtained a new equipment lease line with a borrowing capability of $1,500,000. We have the ability to draw down on this line until the end of 2008.  The repayment period will be for three years beginning on the date of each draw down, with the interest rate on the line fixed at each draw down. Each line has a bargain purchase buyout provision of $1.  During the three months ended March 31, 2008, we drew down approximately $219,000, which is included in our capital lease obligation on our balance sheet. Approximately $1.3 million remained available under the equipment lease line as of March 31, 2008.

10. Equity Financings

During the first quarter of 2008, we completed an underwritten public offering in which we sold 5,000,000 shares of our common stock at a price to the public of $27.00 per share. We received net proceeds of approximately $127.5 million after deducting underwriting discounts and commissions and offering expenses.

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Report of Independent Registered Public Accounting Firm

The Board of Directors

Rigel Pharmaceuticals, Inc.

We have reviewed the condensed balance sheet of Rigel Pharmaceuticals, Inc. as of March 31, 2008, and the related condensed statements of operations for the three-month periods ended March 31, 2008 and 2007, and the condensed statements of cash flows for the three-month periods ended March 31, 2008 and 2007. These financial statements are the responsibility of the Company’s management.

We conducted our review in accordance with the standards of the Public Company Accounting Oversight Board (United States). A review of interim financial information consists principally of applying analytical procedures and making inquiries of persons responsible for financial and accounting matters. It is substantially less in scope than an audit conducted in accordance with the standards of the Public Company Accounting Oversight Board, the objective of which is the expression of an opinion regarding the financial statements taken as a whole. Accordingly, we do not express such an opinion.

Based on our review, we are not aware of any material modifications that should be made to the condensed interim financial statements referred to above for them to be in conformity with U.S. generally accepted accounting principles.

We have previously audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the balance sheet of Rigel Pharmaceuticals, Inc. as of December 31, 2007, and the related statements of operations, stockholders’ equity, and cash flows for the year then ended (not presented herein) and in our report dated March 6, 2008, we expressed an unqualified opinion on those financial statements and included an explanatory paragraph referencing Rigel Pharmaceuticals, Inc.’s change in method of accounting for share-based compensation as of January 1, 2006 and Note 1 to the financial statements.  In our opinion, the information set forth in the accompanying condensed balance sheet as of December 31, 2007, is fairly stated, in all material respects, in relation to the balance sheet from which it has been derived.

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Item 2.    Management’s Discussion and Analysis of Financial Condition and Results of Operations

This discussion and analysis should be read in conjunction with our financial statements and the accompanying notes included in this report and the audited financial statements and accompanying notes included in our Annual Report on Form 10-K for the year ended December 31, 2007. Operating results for the three months ended March 31, 2008 are not necessarily indicative of results that may occur in future periods.

This report contains statements that involve expectations, plans or intentions. We usually use words such as “may,” “will,” “should,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “intend,” or the negative of these terms or similar expressions to identify these forward-looking statements. These statements appear throughout this quarterly report on Form 10-Q and are statements regarding our current expectation, belief or intent, primarily with respect to our operations and related industry developments. Examples of these statements include, but are not limited to, statements regarding the following: our business and scientific strategies; the progress of our product development programs, including clinical testing; our corporate collaborations, including revenues that may be received from these collaborations; our drug discovery technologies; our research and development expenses; protection of our intellectual property; sufficiency of our cash resources; and our operations and legal risks. You should not place undue reliance on these forward-looking statements. Our actual results could differ materially from those anticipated in these forward-looking statements for many reasons, including as a result of the risks and uncertainties discussed in the “Risk Factors” in Item 1A of Part II of this quarterly report on Form 10-Q. Any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events. New factors emerge from time to time, and it is not possible for us to predict which factors will arise. In addition, we cannot assess the impact of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements.

Overview

We are a clinical-stage drug development company that discovers and develops novel, small-molecule drugs for the treatment of inflammatory diseases and cancer, as well as viral and metabolic diseases. Our goal is to file one new investigational new drug, or IND, application in a significant indication each year.  We have achieved this goal every year since 2002. Our pioneering research focuses on intracellular signaling pathways and related targets that are critical to disease mechanisms. Our productivity has resulted in strategic collaborations with large pharmaceutical partners to develop and market our product candidates. We have product development programs in inflammatory/autoimmune diseases such as rheumatoid arthritis, thrombocytopenia and asthma, as well as in cancer.

 We have multiple product candidates in development as follows:

·                  R788—Product Candidate for Rheumatoid Arthritis (RA).  R788 is our lead product candidate. It has a novel mechanism of action, inhibiting IgG receptor signaling in macrophages and B-cells.

We recently completed a Phase 2, multi-center, ascending dose, randomized, double-blind, placebo-controlled, dose-ranging clinical trial evaluating three doses of R788 over a 12-week period in RA patients. All patients continued to receive their previously scheduled dose of Methotrexate. In this clinical trial, R788 demonstrated statistically significant efficacy results in treating RA patients at two dose levels. Efficacy assessments for each participant were based on the American College of Rheumatology criteria, which denote a 20% (ACR 20) improvement, at least a 50% (ACR 50) improvement, or at least a 70% (ACR 70) improvement from the baseline assessment at the end of the 12-week treatment period. Patients were also evaluated based on the Disease Activity Score using 28 joint counts, or DAS28, a commonly used measurement outside of the U.S. of disease activity in RA patients. Groups treated with R788 at 100mg and 150mg po bid (orally, twice daily) showed higher ACR20, ACR50, ACR70 and DAS28 response rates than the placebo group. The most common clinically meaningful adverse events noted in the clinical trial were dose-related neutropenia, mild elevations of liver function tests and gastrointestinal side effects. Dose reduction (to one-half the assigned dose by taking the drug once per day) was pre-specified in the protocol and contingent on neutrophil counts and/or liver function tests. Notably, a vast majority of the patients who had their doses reduced successfully completed the clinical trial with minimal safety issues. We expect to initiate a Phase 2b clinical trial evaluating dosing of the patients receiving R788 or placebo over a 24-week period in the first half of 2008. We also expect to initiate a second Phase 2b clinical trial treating RA patients who have failed anti-TNF therapy with R788 in the first half of 2008.

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·                  R788—Product Candidate for Immune Thombocytopenic Purpura (ITP).  Platelet destruction from ITP is mediated by IgG signaling, and R788 is a potent inhibitor of IgG signaling. In preclinical studies, R788 was shown to improve thrombocytopenia in an ITP mouse model. We recently completed an exploratory Phase 2 clinical trial of R788 to evaluate its safety and initial efficacy in chronic ITP patients. In this clinical trial, R788 was orally administered in varying doses for 30 or more days and demonstrated that it can improve platelet counts in highly refractory patients. We are investigating the design for our next clinical trial of R788, which we expect to initiate by the end of 2008.

·                  R788—Product Candidate for B-Cell Lymphoma.  Research has shown that overactivity of the signaling enzyme spleen tyrosine kinase, or Syk, appears to be an essential mechanism in several types of B-cell lymphoma proliferation and that R788 can inhibit the growth of B-cell lymphoma driven by Syk overactivity. In April 2007, we began enrolling patients in a multi-center, Phase 1/2 clinical trial to evaluate the safety and efficacy of R788 for the treatment of patients with B-cell lymphoma. The clinical trial has enrolled 80 patients at 11 major treatment centers in the United States and will focus on certain types of B-cell lymphomas. We expect to report interim results from this clinical trial in the first half of 2008.

·                  R788—Product Candidate for Systemic Lupus Erythematosus (SLE or Lupus).  Preclinical studies have also shown that R788 is highly effective in murine model of lupus.  We expect to initiate a Phase 2 clinical trial in the second half of 2008.

·                  R348—Product Candidate for RA and Other Immune Disorders.  R348  is an orally-available potent, selective JAK3 inhibitor. JAK3 is a cytoplasmic tyrosine kinase that plays an important role in lymphocyte differentiation and proliferation in a variety of autoimmune diseases. We recently began enrolling patients in a Phase 1 clinical trial to evaluate the safety and tolerability of R348. We expect to complete dosing for this Phase 1 trial in the first half of 2008.

·                  R763—Product Candidate for Oncology.  R763/AS703569 is a potent, highly-selective, small-molecule inhibitor of aurora kinase. In October 2005, we signed a licensing agreement with Merck Serono that gave Merck Serono an exclusive license to develop and commercialize inhibitors in our aurora kinase program, including R763/AS703569. In November 2007, Merck Serono exercised its option to add Japan to the territories covered under the current aurora kinase collaboration with respect to R763/AS703569, resulting in a milestone payment to us of $3.0 million. Under the agreement, Merck Serono is responsible for the further development and commercialization of R763/AS703569. In September 2006, Merck Serono initiated a Phase 1 multi-center clinical trial to evaluate R763/AS703569 for the treatment of patients with refractory solid tumors. In February 2007, Merck Serono began an additional Phase 1 clinical trial evaluating R763/AS703569 on patients with hematological malignancies. Merck Serono has indicated that interim results from these Phase 1 clinical trials are expected in the second half of 2008. In July 2007, Merck Serono initiated its third Phase 1 clinical trial, designed to determine the maximum tolerated dose, safety and dosing regimen of R763/AS703569 in combination with gemcitabine, a commonly prescribed chemotherapeutic agent administered by intravenous infusion. The clinical trial will evaluate two different treatment regimens in which R763/AS703569 will be given in sequence with gemcitabine over 21-day cycles. As many as 72 patients with advanced malignancies, including pancreatic, ovarian, breast, non-small cell lung and colorectal, will be evaluated.

·                  R343—Product Candidate for Asthma.  In the first quarter of 2005, we announced a collaborative research and license agreement with Pfizer for the development of inhaled products for the treatment of allergic asthma and other respiratory diseases, such as chronic obstructive pulmonary disease. The collaboration is focused on our preclinical small molecule compounds, which inhibit IgE receptor signaling in respiratory tract mast cells by blocking Syk, a novel drug target for respiratory diseases. Mast cells play important roles in both early and late phase allergic reactions, and Syk inhibitors could prevent both phases.

In May 2006, Pfizer selected R343 to commence advanced preclinical development in allergic asthma via intrapulmonary delivery. In December 2007, Pfizer commenced a Phase 1 clinical trial of an inhaled formulation of R343 for the treatment of allergic asthma, resulting in a milestone payment to us of $5.0 million.

Corporate Collaborations

We conduct research and development programs independently and in connection with our corporate collaborations. We currently have collaborations with six major pharmaceutical/biotechnology companies. These collaborations include a collaboration with Janssen Pharmaceutica N.V., a division of Johnson & Johnson, relating to oncology therapeutics and diagnostics; two collaborations with Pfizer, one initiated in 1999 in immunology and the other in January 2005, relating to intrapulmonary asthma and allergy therapeutics; a collaboration with Novartis Pharma AG, or Novartis, with respect to four different programs relating to immunology, oncology and chronic bronchitis; a collaboration with Daiichi

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Pharmaceuticals Co., Ltd., or Daiichi, relating to oncology; a collaboration with Merck & Co., Inc., or Merck, also relating to oncology, a collaboration with Merck Serono, relating to our aurora kinase inhibitor program. None of these collaborations currently provides us with regular research reimbursement. In all of these collaborations, if certain conditions are met, we are entitled to receive future milestone payments and royalties. We can not guarantee that these conditions will be met or that research and development efforts will be successful. As a result, we may not receive any further milestone payments or royalties under these agreements.

Equity Financings

During the first quarter of 2008, we completed an underwritten public offering in which we sold 5,000,000 shares of our common stock at a price to the public of $27.00 per share. We received net proceeds of approximately $127.5 million after deducting underwriting discounts and commissions and offering expenses.

Recent Accounting Pronouncements

On December 12, 2007, the FASB ratified the consensus reached by the EITF on EITF Issue No. 07-1. “Accounting for Collaborative Arrangements,” or EITF 07-1. EITF 07-1 defines collaborative arrangements and establishes reporting requirements for transactions between participants in a collaborative arrangement and between participants in the arrangement and third parties. EITF 07-1 is effective for financial statements issued for fiscal years beginning after December 15, 2008. We are currently evaluating the impact of adopting EITF 07-1 on our financial statements and cannot estimate the impact of adoption at this time.

On June 27, 2007, the FASB ratified the consensus reached by the EITF on EITF Issue No. 07-3, “Accounting for Advance Payments for Goods or Services to Be Used in Future Research and Development Activities,” or EITF 07-3. EITF 07-3 requires companies to defer and capitalize prepaid, nonrefundable research and development payments to third parties, and amortize them over the period that the research and development activities are performed or the services are provided, subject to an assessment of recoverability. EITF 07-3 is effective for new contracts entered into during fiscal years beginning after December 15, 2007, including interim periods within those fiscal years. The adoption of EITF 07-3 did not have a material affect on our financial statements.

In September 2006, the FASB issued SFAS 157, “Fair Value Measurements,” or SFAS 157. This standard defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles, and expands disclosures about fair value measurements. SFAS 157 is effective for financial statements issued for fiscal years beginning after November 15, 2007, except that under FASB Staff Position 157-2, “Effective Date of FASB Statement No. 157,” companies are allowed to delay the effective date of SFAS 157 for non-financial assets and non-financial liabilities that are not recognized or disclosed at fair value on a recurring basis until fiscal years beginning after November 15, 2008.  We have adopted SFAS 157 with regard to all financial assets and liabilities in our financial statements going forward, including the three months ended March 31, 2008 and have elected to delay the adoption of SFAS 157 for non-financial assets and non-financial liabilities for one year.  For further discussion of SFAS 157, see Note 8 to the Condensed Financial Statements.

In February 2007, the FASB issued SFAS No. 159, “The Fair Value Option for Financial Assets and Financial Liabilities—Including an amendment of FASB Statement No. 115,” or SFAS 159. SFAS 159 permits entities to choose to measure many financial instruments and certain other items at fair value. Entities that elect the fair value option will report unrealized gains and losses in earnings at each subsequent reporting date. The fair value option may be elected on an instrument-by-instrument basis, with few exceptions. SFAS 159 also establishes presentation and disclosure requirements to facilitate comparisons between companies that choose different measurement attributes for similar assets and liabilities. SFAS 159 is effective for fiscal years beginning after November 15, 2007. We elected not to adopt the fair value option of SFAS 159 at this time.

Critical Accounting Policies and the Use of Estimates

Our discussion and analysis of our financial condition and results of operations is based upon our condensed financial statements, which have been prepared in accordance with U.S generally accepted accounting principles for interim financial information. The preparation of these condensed financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. We evaluate our estimates, including those related to terms of the research collaborations (i.e. amortization of upfront fees and certain milestone payments), investments, stock compensation, impairment issues, the estimated useful life of assets and contingencies, on an on-going basis. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making

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judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. We believe that there were no significant changes in our critical accounting policies during the quarter ended March 31, 2008 as compared to those previously disclosed in our annual report on Form 10-K for the year ended December 31, 2007. We believe the following critical accounting policies affect our more significant judgments and estimates used in the preparation of our financial statements:

Revenue Recognition

We recognize revenue from our collaboration arrangements. Our revenue arrangements with multiple elements are evaluated under Emerging Issues Task Force No. 00-21, “Revenue Arrangements with Multiple Deliverables,” and are divided into separate units of accounting if certain criteria are met, including whether the delivered element has stand-alone value to the customer and whether there is objective and reliable evidence of the fair value of any undelivered items. The consideration we receive is allocated among the separate units based on their respective fair values, and the applicable revenue recognition criteria are applied to each of the separate units. Advance payments received in excess of amounts earned are classified as deferred revenue until earned.

Non-refundable, up-front payments received in connection with research and development collaboration agreements, including technology access fees, are deferred and recognized on a straight-line basis over the relevant periods of continuing involvement, generally the research term. When a research term is not specified, we estimate the time it will take us to complete our deliverables under the contract and recognize the upfront fee using the straight-line method over that time period. We review our estimates every quarter for reasonableness.

Revenue related to collaborative research with our corporate collaborators is recognized as research services are performed over the related development periods for each contract. Under these agreements, we are required to perform research and development activities as specified in the applicable agreement. The payments received are not refundable and are generally based on a contractual cost per full-time equivalent employee working on the project. Research and development expenses under the collaborative research agreements, except for the Merck collaboration signed in November 2004 related to ubiquitin ligases, approximate or exceed the revenue recognized under such agreements over the term of the respective agreements. For the Merck collaboration, we recognized a pro-rata portion of the invoiced amounts for funding of our research scientists based on the headcount dedicated to the project. When the research portion of the collaboration ended in May 2007, we recognized the full amount of the deferred revenue related to the contract because we had no further obligations under the Merck collaboration. It is our policy to recognize revenue based on our level of effort expended, and that revenue recognized will not exceed amounts billable under the arrangement.

Revenues associated with at-risk milestones pursuant to collaborative agreements are recognized based upon the achievement of the milestones as set forth in the applicable agreement.

Stock-based Compensation

The determination of the fair value of share-based payment awards on the date of grant using the Black-Scholes option-pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables. These variables include, but are not limited to, volatility, expected term, risk-free interest rate and dividends. We estimate volatility using our historical share price performance over the expected life of the option up to the point where we have historical market data. For expected term, among other things, we take into consideration our historical data of options exercised, cancelled and expired. The risk-free rate is based on the U.S. Treasury constant maturity rate. We have not paid and do not expect to pay dividends. In order to calculate share-based expense, we also estimate the forfeiture rate using our historical experience with options that cancel before they vest.

If these factors change and we employ different assumptions in the application of SFAS 123(R) in future periods, the compensation expense that we record under SFAS 123(R) may differ significantly from what we have recorded in the current period. Therefore, we believe it is important to be aware of the high degree of subjectivity involved when using option pricing models to estimate share-based compensation under SFAS 123(R).

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Results of Operations

Three Months Ended March 31, 2008 and 2007

Revenues

Contract revenues by collaborator were:

There were no contract revenues reported during the three months ended March 31, 2008. Contract revenues from collaborations for the three months ended March 31, 2007 consisted of approximately $1.0 million in FTE revenue from Merck, approximately $0.9 million amortization of license and milestone payments from Merck, and approximately $0.7 million amortization of license payments from Pfizer. We have no deferred revenue as of March 31, 2008. Our potential revenues for the remainder of 2008 may include certain milestone payments from our current collaborations and any new collaboration arrangement we may enter into.

Research and Development Expenses

The increase in research and development expenses for the three months ended March 31, 2008, as compared to the same period in 2007, was primarily due to an increase in clinical costs and stock-based compensation expense, as discussed under “Stock-based Compensation” below.  The increase in clinical costs was attributable to increased costs associated with manufacturing R788 material to be used in the Phase 2b clinical studies of R788 in RA.  We expect our research and development expenses to increase for the remainder of 2008 as we commence dosing patients in our Phase 2b clinical trials of R788 for RA and initiate our Phase 2 trial of R788 in lupus and continue to manufacture R788 material to be used in these trials.

The scope and magnitude of future research and development expenses are difficult to predict given the number of studies that we will need to conduct for any of our potential products, as well as our limited capital resources. In general, biopharmaceutical development involves a series of steps, beginning with identification of a potential target and including, among others, proof of concept in animals and Phase 1, 2 and 3 clinical studies in humans. Each of these steps is typically more expensive than the previous step. Success in early stages of development, therefore, results in increasing expenditures

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for such product candidate. Our research and development expenditures currently include costs for scientific personnel, supplies, equipment, consultants, sponsored research, allocated facility costs, costs related to preclinical and clinical trials, and stock-based compensation.

General and Administrative Expenses

The increase in general and administrative expenses for the three months ended March 31, 2008, as compared to the same period in 2007, is primarily attributable to an increase in stock-based compensation expense, as discussed under “Stock-based Compensation” below, and personnel costs.

Stock-Based Compensation

The increase in stock-based compensation expense for the three months ended March 31, 2008, as compared to the same period in 2007, was due to an increased valuation of options granted in January 2008 attributable to our increased stock price and volatility, as well as increased number of shares subject to options granted in the first quarter of 2008 as compared to the first quarter of 2007.

Interest Income

Interest income results from our interest-bearing cash and investment balances. Interest income increased for the three months ended March 31, 2008, as compared to the same period in 2007, due to an increase in our cash resulting from our public offering completed in February 2008 in which we received net proceeds of approximately $127.5 million.

Interest Expense

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Interest expense is the result of our capital lease obligations associated with fixed asset acquisitions. Interest expense decreased for the three months ended March 31, 2008, as compared to the same period in 2007, due to the decrease in capital lease obligations outstanding during those periods.

Liquidity and Capital Resources

Cash Requirements

We have financed our operations from inception primarily through sales of equity securities, contract payments under our collaboration agreements and equipment financing arrangements. We have consumed substantial amounts of capital to date, and our operating expenditures are expected to increase over the next several years.

We believe that our existing capital resources will be sufficient to support our current operating plan through at least the next 12 months. In the foreseeable future, our operations will require significant additional funding, in large part due to our research and development expenses, future preclinical and clinical testing costs and the absence of any revenues from product sales. The amount of future funds needed will depend largely on the timing and structure of potential future collaborations. We do not know whether additional financing will be available when needed, or that, if available, we will obtain financing on terms favorable to our stockholders or us.

To the extent we raise additional capital by issuing equity securities, our stockholders could at that time experience substantial dilution. To the extent that we raise additional funds through collaboration and licensing arrangements, we may be required to relinquish some rights to our technologies or product candidates, or grant licenses on terms that are not favorable to us.

Our future funding requirements will depend upon many factors, including, but not limited to:

·                  the progress and success of clinical trials and preclinical activities (including studies and manufacture of materials) of our product candidates conducted by us or our collaborative partners or licensees;

·                  our ability to establish new collaborations;

·                  the progress of research programs carried out by us;

·                  any changes in the breadth of our research and development programs;

·                  our ability to meet the milestones identified in our collaborative agreements that trigger payments;

·                  the progress of the research and development efforts of our collaborative partners;

·                  our ability to acquire or license other technologies or compounds that we seek to pursue;

·                  our ability to manage our growth;

·                  competing technological and market developments;

·                  the costs and timing of obtaining, enforcing and defending our patent and intellectual rights;

·                  the costs and timing of regulatory approvals and filings by us and our collaborators; and

·                  expenses associated with unforeseen litigation.

Insufficient funds may require us to delay, scale back or eliminate some or all of our research or development programs, to lose rights under existing licenses or to relinquish greater or all rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose or may adversely affect our ability to operate as a

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going concern. As of March 31, 2008, we had approximately $209.7 million in cash, cash equivalents and available-for-sale securities, as compared to approximately $108.3 million as of December 31, 2007, an increase of approximately $101.4 million. The increase was primarily attributable to net proceeds of approximately $127.5 million from our public offering in the first quarter of 2008, offset by operating spending for the three months ended March 31, 2008. For the three months ended March 31, 2008 and 2007, we maintained an investment portfolio primarily in money market funds, government-sponsored enterprise securities, corporate bonds and commercial paper. Cash in excess of immediate requirements is invested with regard to liquidity and capital preservation. Wherever possible, we seek to minimize the potential effects of concentration and degrees of risk.

Contractual Obligations

As of March 31, 2008, we had the following contractual commitments (by fiscal year):

(1)             As of March 31, 2008, we had approximately $1.8 million in capital lease obligations (including the interest portion) associated with our equipment. All existing capital lease agreements as of March 31, 2008 are secured by the equipment financed, bearing interest at rates between 5.8% and 12.2% and are due in monthly installments through 2010.

Item 3.           Quantitative and Qualitative Disclosures About Market Risk

During the three months ended March 31, 2008, there were no material changes to our market risk disclosures as set forth in Part II, Item 7A, “Quantitative and Qualitative Disclosures About Market Risk,” of our Annual Report on Form 10-K for the year ended December 31, 2007.

Item 4.    Controls and Procedures

Evaluation of Disclosure Controls and Procedures. Based on our management’s evaluation (with the participation of our chief executive officer and chief financial officer), our chief executive officer and chief financial officer have concluded that our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended), were effective as of March 31, 2008.

Changes in Internal Controls. There were no changes in our internal controls over financial reporting during the quarter ended March 31, 2008 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on the Effectiveness of Controls. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the controls are met. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues, if any, within a company have been detected. Accordingly, our disclosure controls and procedures are designed to provide reasonable, not absolute, assurance that the objectives of our disclosure control system are met and, as set forth above, our chief executive officer and chief financial officer have concluded, based on their evaluation as of the end of the period covered by this quarterly report on Form 10-Q, that our disclosure controls and procedures were sufficiently effective to provide reasonable assurance that the objectives of our disclosure control system were met.

PART II. OTHER INFORMATION

Item 1A. Risk Factors

In evaluating our business, you should carefully consider the following risks, as well as the other information contained in this Quarterly Report on Form 10-Q. If any of the following risks actually occurs, our business, financial condition and operating results could be harmed. The risks and uncertainties described below are not the only ones facing

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us. Additional risks and uncertainties not presently known to us, or that we currently see as immaterial, may also harm our business. We have marked with an asterisk (*) those risk factors below that reflect a substantive change from the risk factors included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 7, 2008.

We will need additional capital in the future to sufficiently fund our operations and research.*

We have consumed substantial amounts of capital to date, and operating expenditures are expected to increase over the next several years as we expand our research and development activities. We believe that our existing capital resources will be sufficient to support our current operating plan through at least the next 12 months. In the foreseeable future, our operations will require significant additional funding, in large part due to our research and development expenses, future preclinical and clinical-testing costs, and the absence of any revenues from product sales. The amount of future funds needed will depend largely on the timing and structure of potential future collaborations. We do not know whether additional financing will be available when needed, or that, if available, we will obtain financing on terms favorable to our stockholders or us.

To the extent we raise additional capital by issuing equity securities, our stockholders could at that time experience substantial dilution. To the extent that we raise additional funds through collaboration and licensing arrangements, we may be required to relinquish some rights to our technologies or product candidates, or grant licenses on terms that are not favorable to us.

Our future funding requirements will depend on many uncertain factors.

Our future funding requirements will depend upon many factors, including, but not limited to:

·                  the progress and success of clinical trials and preclinical activities (including studies and manufacture of materials) of our product candidates conducted by us or our collaborative partners or licensees;

·                  our ability to establish new collaborations;

·                  the progress of research programs carried out by us;

·                  any changes in the breadth of our research and development programs;

·                  our ability to meet the milestones identified in our collaborative agreements that trigger payments;

·                  the progress of the research and development efforts of our collaborative partners;

·                  our ability to acquire or license other technologies or compounds that we seek to pursue;

·                  our ability to manage our growth;

·                  competing technological and market developments;

·                  the costs and timing of obtaining, enforcing and defending our patent and intellectual property rights;

·                  the costs and timing of regulatory approvals and filings by us and our collaborators; and

·                  expenses associated with unforeseen litigation.

Insufficient funds may require us to delay, scale back or eliminate some or all of our research and development programs, to lose rights under existing licenses or to relinquish greater or all rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose or may adversely affect our ability to operate as a going concern.

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Our success as a company is uncertain due to our history of operating losses and the uncertainty of future profitability.*

Due in large part to the significant research and development expenditures required to identify and validate new product candidates and pursue our development efforts, we have not been profitable and have incurred operating losses since we were incorporated in June 1996.   The extent of our future losses and the timing of potential profitability are highly uncertain, and we may never achieve profitable operations. We incurred net losses of approximately $27.3 million for the three months ended March 31, 2008, $74.3 million in 2007 and $37.6 million in 2006. Currently, our revenues are generated solely from research milestone payments pursuant to our collaboration agreements and licenses and are insufficient to generate profitable operations. As of March 31, 2008, we had an accumulated deficit of approximately $396.7 million. We expect to incur losses for at least the next several years and expect that these losses could increase as we expand our research and development activities and incur significant clinical and testing costs.

There is a high risk that drug discovery and development efforts might not successfully generate good product candidates.

At the present time, the majority of our operations are in various stages of drug identification and development. We currently have four product compounds in the clinical testing stage: one with indications for RA, ITP and B-cell lymphoma, which is proprietary to our company; one in safety testing and intended for psoriasis, RA, and other immunological indications, which is proprietary to our company; one with three indications for oncology, which is subject to a collaboration agreement with Merck Serono; and one in safety testing and intended for allergic asthma, which is subject to a collaboration agreement with Pfizer. In our industry, it is statistically unlikely that the limited number of compounds that we have identified as potential product candidates will actually lead to successful product development efforts, and we do not expect any drugs resulting from our research to be commercially available for several years, if at all.

Our compounds in clinical trials and our future leads for potential drug compounds are subject to the risks and failures inherent in the development of pharmaceutical products. These risks include, but are not limited to, the inherent difficulty in selecting the right drug and drug target and avoiding unwanted side effects as well as unanticipated problems relating to product development, testing, regulatory compliance, manufacturing, competition and costs and expenses that may exceed current estimates. For example, in our clinical trials conducted to-date, use of R788 has resulted in dose related neutropenia, elevated liver enzymes and gastrointestinal side effects. These side effects may limit or delay enrollment of patients in future trials and we may observe additional side effects in larger clinical testing in future trials. If approved by the FDA, the side effect profile of R788 may also result in a narrowly approved indication for use of the product, especially in light of other drugs currently available to treat RA, dependent on the safety profile of R788 relative to those drugs.

The results of preliminary studies do not necessarily predict clinical or commercial success, and larger later-stage clinical trials may fail to confirm the results observed in the preliminary studies. Our lead product candidate is in early development, having recently completed initial Phase 2 clinical trials in two indications. We will need to conduct additional Phase 2 trials, with larger numbers of patients, before proceeding into Phase 3 trials with R788 for either indication. Furthermore, our Phase 2 clinical trial for ITP was conducted in highly refractory patients, as opposed to treatment-naive patients. If efficacy is not demonstrated among treatment-naive patients, any approved indication for ITP will be limited to a subset of the patient population. Finally, with respect to our own compounds in development, we have established anticipated timelines with respect to the initiation or completion of clinical studies based on existing knowledge of the compound. However, we cannot provide assurance that we will meet any of these timelines for clinical development.

Because of the uncertainty of whether the accumulated preclinical evidence (pharmacokinetic, pharmacodynamic, safety and/or other factors) or early clinical results will be observed in later clinical trials, we can make no assurances regarding the likely results from our future clinical trials or the impact of those results on our business

We might not be able to commercialize our product candidates successfully if problems arise in the clinical testing and approval process.

Commercialization of our product candidates depends upon successful completion of preclinical studies and clinical trials. Preclinical testing and clinical development are long, expensive and uncertain processes. We do not know whether we, or any of our collaborative partners, will be permitted to undertake clinical trials of potential products beyond the trials already concluded and the trials currently in process. It will take us, or our collaborative partners several years to complete any such testing, and failure can occur at any stage of testing. Interim results of trials do not necessarily predict final results, and acceptable results in early trials may not be repeated in later trials. A number of companies in the pharmaceutical industry, including biotechnology companies, have suffered significant setbacks in advanced clinical trials, even after achieving promising results in earlier trials. Moreover, we or our collaborative partners or regulators may decide to discontinue development of any or all of these projects at any time for commercial, scientific or other reasons.

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Delays in clinical testing could result in increased costs to us.

Significant delays in clinical testing could materially impact our product development costs and timing. We do not know whether planned clinical trials will begin on time, will need to be halted or revamped or will be completed on schedule, or at all. Clinical trials can be delayed for a variety of reasons, including delays in obtaining regulatory approval to commence a study, delays from scale up, delays in reaching agreement on acceptable clinical study agreement terms with prospective clinical sites, delays in obtaining institutional review board approval to conduct a study at a prospective clinical site or delays in recruiting subjects to participate in a study.

In addition, we typically rely on third-party clinical investigators to conduct our clinical trials and other third-party organizations to oversee the operations of such trials and to perform data collection and analysis. As a result, we may face additional delaying factors outside our control if these parties do not perform their obligations in a timely fashion. While we have not yet experienced delays that have materially impacted our clinical trials or product development costs, delays of this sort could occur for the reasons identified above or other reasons. If we have delays in testing or approvals, our product development costs will increase. For example, we may need to make additional payments to third-party investigators and organizations to retain their services or we may need to pay recruitment incentives. If the delays are significant, our financial results and the commercial prospects for our product candidates will be harmed, and our ability to become profitable will be delayed.

We lack the capability to manufacture compounds for development and rely on third parties to manufacture our product candidates, and we may be unable to obtain required material in a timely manner, at an acceptable cost or at a quality level required to receive regulatory approval.

We currently do not have manufacturing capabilities or experience necessary to produce our product candidate R788. We rely on a single manufacturer for the R788 product for clinical trials. We will rely on manufacturers to deliver materials on a timely basis and to comply with applicable regulatory requirements, including the FDA’s current Good Manufacturing Practices, or GMP. These outsourcing efforts with respect to manufacturing preclinical and clinical supplies will result in a dependence on our suppliers to timely manufacture and deliver sufficient quantities of materials produced under GMP conditions to enable us to conduct planned preclinical studies, clinical trials and, if possible, to bring products to market in a timely manner.

Our current and anticipated future dependence upon these third-party manufacturers may adversely affect our ability to develop and commercialize product candidates on a timely and competitive basis. These manufacturers may not be able to produce material on a timely basis or manufacture material at the quality level or in the quantity required to meet our development timelines and applicable regulatory requirements. We may not be able to maintain or renew our existing third-party manufacturing arrangements, or enter into new arrangements, on acceptable terms, or at all. Our third-party manufacturers could terminate or decline to renew our manufacturing arrangements based on their own business priorities, at a time that is costly or inconvenient for us. If we are unable to contract for the production of materials in sufficient quantity and of sufficient quality on acceptable terms, our planned clinical trials may be significantly delayed. Manufacturing delays could postpone the filing of our IND applications and/or the initiation of clinical trials that we have currently planned.

Our third-party manufacturers may not be able to comply with the GMP regulations, other applicable FDA regulatory requirements or similar regulations applicable outside of the United States. Additionally, if we are required to enter into new supply arrangements, we may not be able to obtain approval from the FDA of any alternate supplier in a timely manner, or at all, which could delay or prevent the clinical development and commercialization of any related product candidates. Failure of our third-party manufacturers or us to obtain approval from the FDA or to comply with applicable regulations could result in sanctions being imposed on us, including fines, civil penalties, delays in or failure to grant marketing approval of our product candidates, injunctions, delays, suspension or withdrawal of approvals, license revocation, seizures or recalls of products and compounds, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect our business.

Because most of our expected future revenues are contingent upon collaborative and license agreements, we might not meet our strategic objectives.

Our ability to generate revenue in the near term depends on our ability to enter into additional collaborative agreements with third parties and to maintain the agreements we currently have in place. Our ability to enter into new collaborations and the revenue, if any, that may be recognized under these collaborations is highly uncertain. If we are unable to enter into new collaborations, our business prospects could be harmed, which could have an immediate adverse effect on the trading price of our stock.

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To date, most of our revenues have been related to the research phase of each of our collaborative agreements. Such revenues are for specified periods, and the impact of such revenues on our results of operations is partially offset by corresponding research costs. Following the completion of the research phase of each collaborative agreement, additional revenues may come only from milestone payments and royalties, which may not be paid, if at all, until some time well into the future. The risk is heightened due to the fact that unsuccessful research efforts may preclude us from receiving any milestone payments under these agreements. Our receipt of revenues from collaborative arrangements is also significantly affected by the timing of efforts expended by us and our collaborators and the timing of lead compound identification. In late 2001, we recorded the first revenue from achievement of milestones in both the Pfizer and Johnson & Johnson collaborations. In addition, we have subsequently received milestone payments from Novartis, Daiichi, Merck, Merck Serono and Pfizer. Under many agreements, however, milestone payments may not be earned until the collaborator has advanced product candidates into clinical testing, which may never occur or may not occur until some time well into the future. If we are not able to generate revenue under our collaborations when and in accordance with our expectations or the expectations of industry analysts, this failure could harm our business and have an immediate adverse effect on the trading price of our stock.

Our business requires us to generate meaningful revenue from royalties and licensing agreements. To date, we have not received any revenue from royalties for the commercial sale of drugs, and we do not know when we will receive any such revenue, if at all. Likewise, we have not licensed any lead compounds or drug development candidates to third parties, and we do not know whether any such license will be entered into on acceptable terms in the future, if at all.

If our current corporate collaborations or license agreements are unsuccessful, our research and development efforts could be delayed.

Our strategy depends upon the formation and sustainability of multiple collaborative arrangements and license agreements with third parties in the future. We rely on these arrangements for not only financial resources, but also for expertise that we expect to need in the future relating to clinical trials, manufacturing, sales and marketing, and for licenses to technology rights. To date, we have entered into several such arrangements with corporate collaborators; however, we do not know if such third parties will dedicate sufficient resources or if any development or commercialization efforts by third parties will be successful. Should a collaborative partner fail to develop or commercialize a compound or product to which it has rights from us for any reason including corporate restructuring, such failure might delay ongoing research and development efforts at Rigel, because we might not receive any future milestone payments, and we would not receive any royalties associated with such compound or product. In addition, the continuation of some of our partnered drug discovery and development programs may be dependent on the periodic renewal of our corporate collaborations.

The research phase of our collaboration with Johnson & Johnson ended in 2003, and the research phases conducted at our facilities under our broad collaboration with Novartis ended in 2004. The research phase of our corporate collaboration agreement with Daiichi ended in 2005. In 2004, we signed a new corporate collaboration with Merck, and the research phase of this collaboration ended in May 2007. In 2005, we signed additional collaborations with Pfizer and Merck Serono. Each of our collaborations could be terminated by the other party at any time, and we may not be able to renew these collaborations on acceptable terms, if at all, or negotiate additional corporate collaborations on acceptable terms, if at all. If these collaborations terminate or are not renewed, any resultant loss of revenues from these collaborations or loss of the expertise of our collaborative partners could adversely affect our business.

Conflicts also might arise with collaborative partners concerning proprietary rights to particular compounds. While our existing collaborative agreements typically provide that we retain milestone payments and royalty rights with respect to drugs developed from certain derivative compounds, any such payments or royalty rights may be at reduced rates, and disputes may arise over the application of derivative payment provisions to such drugs, and we may not be successful in such disputes.

We are also a party to various license agreements that give us rights to use specified technologies in our research and development processes. The agreements pursuant to which we have in-licensed technology permit our licensors to terminate the agreements under certain circumstances. If we are not able to continue to license these and future technologies on commercially reasonable terms, our product development and research may be delayed.

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If conflicts arise between our collaborators or advisors and us, any of them may act in their self-interest, which may be adverse to our stockholders’ interests.

If conflicts arise between us and our corporate collaborators or scientific advisors, the other party may act in its self-interest and not in the interest of our stockholders. Some of our corporate collaborators are conducting multiple product development efforts within each disease area that is the subject of the collaboration with us or may be acquired or merged with a company having a competing program. In some of our collaborations, we have agreed not to conduct, independently or with any third party, any research that is competitive with the research conducted under our collaborations. Our collaborators, however, may develop, either alone or with others, products in related fields that are competitive with the products or potential products that are the subject of these collaborations. Competing products, either developed by our collaborators or to which our collaborators have rights, may result in their withdrawal of support for our product candidates.

If any of our corporate collaborators were to breach or terminate its agreement with us or otherwise fail to conduct the collaborative activities successfully and in a timely manner, the preclinical or clinical development or commercialization of the affected product candidates or research programs could be delayed or terminated. We generally do not control the amount and timing of resources that our corporate collaborators devote to our programs or potential products. We do not know whether current or future collaborative partners, if any, might pursue alternative technologies or develop alternative products either on their own or in collaboration with others, including our competitors, as a means for developing treatments for the diseases targeted by collaborative arrangements with us.

Our success is dependent on intellectual property rights held by third parties and us, and our interest in such rights is complex and uncertain.

Our success will depend to a large part on our own, our licensees’ and our licensors’ ability to obtain and defend patents for each party’s respective technologies and the compounds and other products, if any, resulting from the application of such technologies. We have over 200 pending patent applications and over 100 issued patents in the United States that are owned or exclusively licensed in our field as well as pending corresponding foreign patent applications. In the future, our patent position might be highly uncertain and involve complex legal and factual questions. For example, we may be involved in interferences before the United States Patent and Trademark Office. Interferences are complex and expensive legal proceedings and there is no assurance we will be successful in such proceedings. An interference could result in our losing our patent rights and/or our freedom to operate and/or require us to pay significant royalties. Additional uncertainty may result because no consistent policy regarding the breadth of legal claims allowed in biotechnology patents has emerged to date. Accordingly, we cannot predict the breadth of claims allowed in our or other companies’ patents.

Because the degree of future protection for our proprietary rights is uncertain, we cannot ensure that:

·                  we were the first to make the inventions covered by each of our pending patent applications;

·                  we were the first to file patent applications for these inventions;

·                  others will not independently develop similar or alternative technologies or duplicate any of our technologies;

·                  any of our pending patent applications will result in issued patents;

·                  any patents issued to us or our collaborators will provide a basis for commercially-viable products or will provide us with any competitive advantages or will not be challenged by third parties;

·                  we will develop additional proprietary technologies that are patentable; or

·                  the patents of others will not have a negative effect on our ability to do business.

We rely on trade secrets to protect technology where we believe patent protection is not appropriate or obtainable; however, trade secrets are difficult to protect. While we require employees, collaborators and consultants to enter into confidentiality agreements, we may not be able to adequately protect our trade secrets or other proprietary information in the event of any unauthorized use or disclosure or the lawful development by others of such information.

We are a party to certain in-license agreements that are important to our business, and we generally do not control the prosecution of in-licensed technology. Accordingly, we are unable to exercise the same degree of control over this intellectual property as we exercise over our internally-developed technology. Moreover, some of our academic institution

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licensors, research collaborators and scientific advisors have rights to publish data and information in which we have rights. If we cannot maintain the confidentiality of our technology and other confidential information in connection with our collaborations, then our ability to receive patent protection or protect our proprietary information will be impaired. In addition, some of the technology we have licensed relies on patented inventions developed using U.S. government resources. The U.S. government retains certain rights, as defined by law, in such patents, and may choose to exercise such rights. Certain of our in-licenses may be terminated if we fail to meet specified obligations. If we fail to meet such obligations and any of our licensors exercise their termination rights, we could lose our rights under those agreements. If we lose any of our rights, it may adversely affect the way we conduct our business. In addition, because certain of our licenses are sublicenses, the actions of our licensors may affect our rights under those licenses.

If a dispute arises regarding the infringement or misappropriation of the proprietary rights of others, such dispute could be costly and result in delays in our research and development activities and partnering.

Our success will also depend, in part, on our ability to operate without infringing or misappropriating the proprietary rights of others. There are many issued patents and patent applications filed by third parties relating to products or processes that are similar or identical to our licensors or ours, and others may be filed in the future. There can be no assurance that our activities, or those of our licensors, will not infringe patents owned by others. We believe that there may be significant litigation in the industry regarding patent and other intellectual property rights, and we do not know if our collaborators or we would be successful in any such litigation. Any legal action against our collaborators or us claiming damages or seeking to enjoin commercial activities relating to the affected products, our methods or processes could:

·                  require our collaborators or us to obtain a license to continue to use, manufacture or market the affected products, methods or processes, which may not be available on commercially reasonable terms, if at all;

·                  prevent us from using the subject matter claimed in the patents held by others;

·                  subject us to potential liability for damages;

·                  consume a substantial portion of our managerial and financial resources; and

·                  result in litigation or administrative proceedings that may be costly, whether we win or lose.

If we are unable to obtain regulatory approval to market products in the United States and foreign jurisdictions, we will not be permitted to commercialize products from our research and development.

Due, in part, to the early stage of our product candidate research and development process, we cannot predict whether regulatory clearance will be obtained for any product that we, or our collaborative partners, hope to develop. Satisfaction of regulatory requirements typically takes many years, is dependent upon the type complexity and novelty of the product and requires the expenditure of substantial resources. Of particular significance to us are the requirements relating to research and development and testing.

Before commencing clinical trials in humans in the United States, we, or our collaborative partners, will need to submit and receive approval from the FDA of an IND. Clinical trials are subject to oversight by institutional review boards and the FDA and:

·                  must be conducted in conformance with the FDA’s good clinical practices and other applicable regulations;

·                  must meet requirements for institutional review board oversight;

·                  must meet requirements for informed consent;

·                  are subject to continuing FDA oversight;

·                  may require large numbers of test subjects; and

·                  may be suspended by us, our collaborators or the FDA at any time if it is believed that the subjects participating in these trials are being exposed to unacceptable health risks or if the FDA finds deficiencies in the IND or the conduct of these trials.

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While we have stated that we intend to file additional INDs, this is only a statement of intent, and we may not be able to do so because we may not be able to identify potential product candidates. In addition, the FDA may not approve any IND in a timely manner, or at all.

Before receiving FDA approval to market a product, we must demonstrate that the product is safe and effective in the patient population and the indication that will be treated. Data obtained from preclinical and clinical activities are susceptible to varying interpretations that could delay, limit or prevent regulatory approvals. In addition, delays or rejections may be encountered based upon additional government regulation from future legislation or administrative action or changes in FDA policy during the period of product development, clinical trials and FDA regulatory review. Failure to comply with applicable FDA or other applicable regulatory requirements may result in criminal prosecution, civil penalties, recall or seizure of products, total or partial suspension of production or injunction, as well as other regulatory action against our potential products or us. Additionally, we have limited experience in conducting and managing the clinical trials necessary to obtain regulatory approval.

If regulatory approval of a product is granted, this approval will be limited to those indications or disease states and conditions for which the product is demonstrated through clinical trials to be safe and efficacious. We cannot ensure that any compound developed by us, alone or with others, will prove to be safe and efficacious in clinical trials and will meet all of the applicable regulatory requirements needed to receive marketing approval.

Outside the United States, our ability, or that of our collaborative partners, to market a product is contingent upon receiving a marketing authorization from the appropriate regulatory authorities. This foreign regulatory approval process typically includes all of the risks associated with FDA approval described above and may also include additional risks.

If our competitors develop technologies that are more effective than ours, our commercial opportunity will be reduced or eliminated.

The biotechnology and pharmaceutical industries are intensely competitive and subject to rapid and significant technological change. Many of the drugs that we are attempting to discover will be competing with existing therapies. In addition, a number of companies are pursuing the development of pharmaceuticals that target the same diseases and conditions that we are targeting. We face competition from pharmaceutical and biotechnology companies both in the United States and abroad.

Our competitors may utilize discovery technologies and techniques or partner with collaborators in order to develop products more rapidly or successfully than we, or our collaborators, are able to do. Many of our competitors, particularly large pharmaceutical companies, have substantially greater financial, technical and human resources than we do. In addition, academic institutions, government agencies and other public and private organizations conducting research may seek patent protection with respect to potentially competitive products or technologies and may establish exclusive collaborative or licensing relationships with our competitors.

We believe that our ability to compete is dependent, in part, upon our ability to create, maintain and license scientifically-advanced technology and upon our and our collaborators’ ability to develop and commercialize pharmaceutical products based on this technology, as well as our ability to attract and retain qualified personnel, obtain patent protection or otherwise develop proprietary technology or processes and secure sufficient capital resources for the expected substantial time period between technological conception and commercial sales of products based upon our technology. The failure by any of our collaborators or us in any of those areas may prevent the successful commercialization of our potential drug targets.

Our competitors might develop technologies and drugs that are more effective or less costly than any that are being developed by us or that would render our technology and potential drugs obsolete and noncompetitive. In addition, our competitors may succeed in obtaining the approval of the FDA or other regulatory agencies for product candidates more rapidly. Companies that complete clinical trials, obtain required regulatory agency approvals and commence commercial sale of their drugs before their competitors may achieve a significant competitive advantage, including certain patent and FDA marketing exclusivity rights that would delay or prevent our ability to market certain products. Any drugs resulting from our research and development efforts, or from our joint efforts with our existing or future collaborative partners, might not be able to compete successfully with competitors’ existing or future products or obtain regulatory approval in the United States or elsewhere.

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Our ability to generate revenues will be diminished if our collaborative partners fail to obtain acceptable prices or an adequate level of reimbursement for products from third-party payors or government agencies.

The drugs we hope to develop may be rejected by the marketplace due to many factors, including cost. Our ability to commercially exploit a drug may be limited due to the continuing efforts of government and third-party payors to contain or reduce the costs of health care through various means. For example, in some foreign markets, pricing and profitability of prescription pharmaceuticals are subject to government control. In the United States, we expect that there will continue to be a number of federal and state proposals to implement similar government control. In addition, increasing emphasis on managed care in the United States will likely continue to put pressure on the pricing of pharmaceutical products. Cost control initiatives could decrease the price that any of our collaborators would receive for any products in the future. Further, cost control initiatives could adversely affect our collaborators’ ability to commercialize our products and our ability to realize royalties from this commercialization.

Our ability to commercialize pharmaceutical products with collaborators may depend, in part, on the extent to which reimbursement for the products will be available from:

·                  government and health administration authorities;

·                  private health insurers; and

·                  other third-party payors.

Significant uncertainty exists as to the reimbursement status of newly-approved healthcare products. Third-party payors, including Medicare, are challenging the prices charged for medical products and services. Government and other third-party payors increasingly are attempting to contain healthcare costs by limiting both coverage and the level of reimbursement for new drugs and by refusing, in some cases, to provide coverage for uses of approved products for disease indications for which the FDA has not granted labeling approval. Third-party insurance coverage may not be available to patients for any products we discover and develop, alone or with collaborators. If government and other third-party payors do not provide adequate coverage and reimbursement levels for our products, the market acceptance of these products may be reduced.

If product liability lawsuits are successfully brought against us, we may incur substantial liabilities and may be required to limit commercialization of our products.

The testing and marketing of medical products entail an inherent risk of product liability. If we cannot successfully defend ourselves against product liability claims, we may incur substantial liabilities or be required to limit commercialization of our products although we are not currently aware of any specific causes for concern with respect to clinical liability claims. We currently do not have product liability insurance, and our inability to obtain sufficient product liability insurance at an acceptable cost to protect against potential product liability claims could prevent or inhibit the commercialization of pharmaceutical products we develop, alone or with corporate collaborators. We, or our corporate collaborators, might not be able to obtain insurance at a reasonable cost, if at all. While under various circumstances we are entitled to be indemnified against losses by our corporate collaborators, indemnification may not be available or adequate should any claim arise.

Our research and development efforts will be seriously jeopardized, if we are unable to attract and retain key employees and relationships.

As a small company with only 168 employees as of March 31, 2008, our success depends on the continued contributions of our principal management and scientific personnel and on our ability to develop and maintain important relationships with leading academic institutions, scientists and companies in the face of intense competition for such personnel. In particular, our research programs depend on our ability to attract and retain highly skilled chemists, other scientists, and development, regulatory and clinical personnel. If we lose the services of any of our personnel, our research and development efforts could be seriously and adversely affected. Our employees can terminate their employment with us at any time.

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We depend on various scientific consultants and advisors for the success and continuation of our research and development efforts.

We work extensively with various scientific consultants and advisors. The potential success of our drug discovery and development programs depends, in part, on continued collaborations with certain of these consultants and advisors. We, and various members of our management and research staff, rely on certain of these consultants and advisors for expertise in our research, regulatory and clinical efforts. Our scientific advisors are not our employees and may have commitments to, or consulting or advisory contracts with, other entities that may limit their availability to us. We do not know if we will be able to maintain such consulting agreements or that such scientific advisors will not enter into consulting arrangements, exclusive or otherwise, with competing pharmaceutical or biotechnology companies, any of which would have a detrimental impact on our research objectives and could have a material adverse effect on our business, financial condition and results of operations.

If we use biological and hazardous materials in a manner that causes injury or violates laws, we may be liable for damages.

Our research and development activities involve the controlled use of potentially harmful biological materials as well as hazardous materials, chemicals and various radioactive compounds. We cannot completely eliminate the risk of accidental contamination or injury from the use, storage, handling or disposal of these materials. In the event of contamination or injury, we could be held liable for damages that result, and such liability could exceed our resources. We are also subject to federal, state and local laws and regulations governing the use, storage, handling and disposal of these materials and specified waste products. The cost of compliance with, or any potential violation of, these laws and regulations could be significant.

Our facilities are located near known earthquake fault zones, and the occurrence of an earthquake or other catastrophic disaster could cause damage to our facilities and equipment, which could require us to cease or curtail operations.

Our facilities are located in the San Francisco Bay Area near known earthquake fault zones and are vulnerable to significant damage from earthquakes. We are also vulnerable to damage from other types of disasters, including fires, floods, power loss, communications failures and similar events. If any disaster were to occur, our ability to operate our business at our facilities would be seriously, or potentially completely, impaired, and our research could be lost or destroyed. In addition, the unique nature of our research activities and of much of our equipment could make it difficult for us to recover from a disaster. The insurance we maintain may not be adequate to cover our losses resulting from disasters or other business interruptions.

Future interest income and value of our investments may be impacted by further declines in interest rates and broader effect of the recent disruption of credit markets.

While we are conservative in our investment policies and invest only in fixed income securities, the interest paid on this type of investment and the value of certain securities may decline in the future as credit markets adjust to the mortgage crisis.

Our stock price may be volatile, and our stockholders’ investment in our stock could decline in value.

The market prices for our securities and those of other biotechnology companies have been highly volatile and may continue to be highly volatile in the future. The following factors, in addition to other risk factors described in this section, may have a significant impact on the market price of our common stock:

·                  the progress and success of clinical trials and preclinical activities (i.e., studies, manufacture of materials) of our product candidates conducted by us or our collaborative partners or licensees;

·                  the receipt or failure to receive the additional funding necessary to conduct our business;

·                  selling by large stockholders;

·                  announcements of technological innovations or new commercial products by our competitors or us;

·                  developments concerning proprietary rights, including patents;

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·                  developments concerning our collaborations;

·                  publicity regarding actual or potential medical results relating to products under development by our competitors or us;

·                  regulatory developments in the United States and foreign countries;

·                  litigation;

·                  economic and other external factors or other disaster or crisis; and

·                  period-to-period fluctuations in financial results.

Future equity issuances or a sale of a substantial number of shares of our common stock may cause the price of our common stock to decline.

Because we may need to raise additional capital in the future to continue to expand our business and our research and development activities, among other things, we may conduct additional equity offerings. If we or our stockholders sell substantial amounts of our common stock (including shares issued upon the exercise of options and warrants) in the public market, the market price of our common stock could fall. A decline in the market price of our common stock could make it more difficult for us to sell equity or equity-related securities in the future at a time and price that we deem appropriate.

Anti-takeover provisions in our charter documents and under Delaware law may make an acquisition of us, which may be beneficial to our stockholders, more difficult.

Provisions of our amended and restated certificate of incorporation and bylaws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us, even if doing so would benefit our stockholders. These provisions:

·                  establish that members of the board of directors may be removed only for cause upon the affirmative vote of stockholders owning a majority of our capital stock;

·                  authorize the issuance of “blank check” preferred stock that could be issued by our board of directors to increase the number of outstanding shares and thwart a takeover attempt;

·                  limit who may call a special meeting of stockholders;

·                  prohibit stockholder action by written consent, thereby requiring all stockholder actions to be taken at a meeting of our stockholders;

·                  establish advance notice requirements for nominations for election to the board of directors or for proposing matters that can be acted upon at stockholder meetings;

·                  provide for a board of directors with staggered terms; and

·                  provide that the authorized number of directors may be changed only by a resolution of our board of directors.

In addition, Section 203 of the Delaware General Corporation Law, which imposes certain restrictions relating to transactions with major stockholders, may discourage, delay or prevent a third party from acquiring us.

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Item 6.           Exhibits

The exhibits listed on the accompanying index to exhibits are filed or incorporated by reference (as stated therein) as part of this Quarterly Report on Form 10-Q.

(1)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on June 24, 2003 and incorporated herein by reference.

(2)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on February 2, 2007 and incorporated herein by reference.

(3)          Filed as an exhibit to Rigel’s Registration Statement on Form S-1 (No. 333-45864), as amended, and incorporated herein by reference.

(4)          Filed as an exhibit to Rigel’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2002 and incorporated herein by reference.

(5)          Filed as an exhibit to Rigel’s Annual Report on Form 10-K, as amended, for the fiscal year ended December 31, 2002 and incorporated herein by reference.

(6)          Filed as an exhibit to Rigel’s Current Report on Form 8-K (No. 000-29889) dated June 24, 2003, and incorporated herein by reference.

(7)          Filed as an exhibit to Rigel’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2006 (No. 000-29889) and incorporated herein by reference.

(8)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on February 14, 2008 and incorporated herein by reference.

(9)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on February 26, 2008 and incorporated herein by reference.

(10)    Filed as an exhibit to Rigel’s Annual Report on Form 10-K filed on March 7, 2008 and incorporated herein by reference.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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INDEX TO EXHIBITS

(1)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on June 24, 2003 and incorporated herein by reference.

(3)          Filed as an exhibit to Rigel’s Current Report on Form 8-K filed on February 2, 2007 and incorporated herein by reference.

(3)          Filed as an exhibit to Rigel’s Registration Statement on Form S-1 (No. 333-45864), as amended, and incorporated herein by reference.

(4)          Filed as an exhibit to Rigel’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2002 and incorporated herein by reference.

(5)          Filed as an exhibit to Rigel’s Annual Report on Form 10-K, as amended, for the fiscal year ended December 31, 2002 and incorporated herein by reference.

(6)          Filed as an exhibit to Rigel’s Current Report on Form 8-K (No. 000-29889) dated June 24, 2003, and incorporated herein by reference.

(7)          Filed as an exhibit to Rigel’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2006 (No. 000-29889) and incorporated herein by reference.