2. SPONSORED RESEARCH AND LICENSE AGREEMENTS

        We conduct research and development programs independently and in connection with our corporate collaborators. We currently have one significant active collaboration with AstraZeneca AB (AZ), relating to fostamatinib for the treatment of rheumatoid arthritis (RA) and other indications. Our collaboration with AZ does not provide us with regular reimbursement of research expenses. If certain conditions are met, we are entitled to receive future payments and royalties. We cannot guarantee that these conditions will be met or that research and development efforts conducted by AZ will be successful. As a result, we may not receive any further payments or royalties under the agreement with AZ.

• AstraZeneca

        In February 2010, we entered into an exclusive worldwide license agreement with AZ for the development and commercialization of our oral spleen tyrosine kinase (SYK) inhibitors for the treatment of human diseases other than those primarily involving respiratory or pulmonary dysfunction. The agreement includes a license of rights to fostamatinib, previously known as R788, our late-stage investigational product candidate for the treatment of RA and other indications. AZ is responsible for conducting and funding all future development, regulatory filings, manufacturing and global commercialization of products containing most of our oral SYK inhibitors. The agreement became effective on March 26, 2010, and we received an upfront payment from AZ of $100.0 million in April 2010.

        Under the agreement, our deliverables were: (i) granting a license of rights to fostamatinib, (ii) transfer of technology (know-how) related to fostamatinib, and (iii) conducting, at our expense, the fostamatinib open label extension study until it was transferred to AZ on September 25, 2010. We concluded that these deliverables should be accounted for as one single unit of accounting, and we recognized the $100.0 million upfront payment received in April 2010 from AZ ratably over the performance period from March 26, 2010, the effective date of the agreement, through September 25, 2010, the completion date of the last deliverable, which was the transfer of the fostamatinib long-term open label extension study to AZ. We elected a straight-line method for recognition of this upfront payment as the effort to advance and transfer the study was consistent over the transition period.

        On September 29, 2010, we announced that we earned $25.0 million from AZ for completing the transfer of the fostamatinib long-term open label extension study to AZ and for their initiation of Phase 3 clinical trials in the fostamatinib program by AZ. AZ is required to pay us up to an additional $320.0 million if specified development, regulatory and product launch events are achieved for fostamatinib, of which up to $25.0 million relates to the achievement of development events, up to $100.0 million relates to the achievement of regulatory events and up to $195.0 million relates to the achievement of product launch events. We are also eligible to receive up to an additional $800.0 million if post-launch specified sales levels are achieved for fostamatinib, as well as significant stepped double-digit royalties on net worldwide sales, if any. Future events that may trigger payments to us under the AZ agreement are based solely on AZ's future efforts and achievements of specified tasks and we cannot assure you that we will receive any or all of the potential contingent payments provided for under this agreement.

        Either party may terminate the agreement if the other party materially breaches the agreement and such breach remains uncured for 60 days after the date of notice of such breach, or in the event of insolvency of the other party. We may also terminate the agreement in its entirety if AZ challenges the validity, enforceability or scope of any of our patents licensed to AZ by us under the agreement. AZ may also terminate the agreement either (1) without cause upon 180 days written notice or (2) upon 30 days written notice in the event of any change of control of Rigel. If neither party terminates the agreement, then the agreement will remain in effect until the cessation of all commercial sales of all products subject to the agreement, including fostamatinib.

• Other Agreements

        We have additional active collaborations with several other partners. Under these collaborations, which we enter into in the ordinary course of business, we received or may be entitled to receive upfront cash payments, progress dependent contingent payments and royalties on any net sales of products under the agreements. Total future contingent payments to us under all of these current collaborations could exceed $160.0 million if all potential product candidates achieved all of the payment triggering events under all of our current collaborations (based on a single product candidate under each agreement). Of this amount, up to $68.9 million relates to the achievement of development events, up to $53.6 million relates to the achievement of regulatory events and up to $37.5 million relates to the achievement of commercial or launch events.

        Since we do not control the research, development or commercialization of the product candidates generated under these collaborations, we are not able to reasonably estimate when, if at all, any contingent payments may be payable to us. As such, the contingent payments we could receive thereunder involve a substantial degree of risk to achieve and may never be received. Accordingly, we do not expect, and investors should not assume, that we will receive all of the potential contingent payments provided for under these collaborations and it is possible that we may never receive any additional significant contingent payments under these collaborations.

        In June 2012, we entered into an exclusive worldwide license agreement with AZ for the development and commercialization of our program, R256, an inhaled janus kinase (JAK) inhibitor shown to inhibit interleukin (IL)-13 and IL-4 signaling, which is being investigated as a treatment for moderate to severe chronic asthma. AZ will be responsible for beginning the first-in-human clinical studies for R256, and for designing and conducting the clinical development of the compound. AZ will also have exclusive rights to commercialize R256 around the world. AZ paid us an upfront payment of $1.0 million in July 2012. Under the agreement, we were obligated to provide the following deliverables: (i) granting a license of rights to our program, and (ii) delivery of a small batch of compound to AZ. We concluded that these deliverables should be accounted for as separate units of accounting. As our obligations with respect to the deliverables were achieved by June 30, 2012, we recognized revenue of $1.0 million in the second quarter of 2012.

        In July 2011, we received a $4.3 million final payment from Merck Serono S.A. (Merck Serono). The final payment from Merck Serono was for the collaboration agreement that was terminated in 2010, and all licenses under the collaboration agreement to aurora kinase inhibitors reverted back to us. The payment did not qualify as a substantive milestone as it related solely to the past performance of Merck Serono. We recognized the receipt of the $4.3 million as revenue in the third quarter of 2011.

        In June 2011, we entered into an exclusive license agreement with BerGenBio AS (BerGenBio) for the development and commercialization of an oncology program. BerGenBio is responsible for all activities it wishes to perform under the license we granted to it. BerGenBio paid us an upfront payment of $500,000 in August 2011. As our obligations with respect to the deliverables under the agreement were achieved by September 30, 2011, we recognized revenue of $500,000 for the period ended September 30, 2011. In July 2012, we received a second payment of $500,000 from BerGenBio due to us twelve months from June 29, 2011, the effective date of the agreement. We recognized the second payment as revenue in the second quarter of 2012.

        In August 2002, we entered into a collaboration agreement with Daiichi Sankyo (Daiichi) to pursue research related to a specific target from a novel class of drug targets called ligases that control cancer cell proliferation through protein degradation. In January 2012, we received a $750,000 payment from Daiichi related to an oncology compound in pre-clinical testing at Daiichi. We have earned, to date, payments under this arrangement totaling $6.5 million and may earn additional payments in connection with the achievement of certain clinical events. The research phase of this three-year collaboration expired in August 2005. Under the terms of the collaboration agreement, we retain the rights to co-develop and co-promote certain products resulting from this collaboration in North America, while Daiichi retains co-development and promotion rights in the remainder of the world. Future events that may trigger payments to us under the Daiichi agreement are based solely on Daiichi's future efforts and achievements of specified events.