Research and License Agreements	3 Months Ended
Mar. 31, 2015
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Research and License Agreements	9. Research and License Agreements In October 2011, the Company and Pfizer entered into a licensing agreement (the Pfizer Agreement) that provides Pfizer an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with sickle cell disease and for other diseases for which the drug candidate may be developed. The Company was responsible for completion of the Phase 2 trial, after which Pfizer will assume all further development and commercialization responsibilities. Upon execution of the Pfizer Agreement, the Company received an up-front payment of $22.5 million. The Pfizer Agreement also provides for potential milestone payments of up to $115.0 million upon the achievement of specified development milestones, including the dosing of the first patients in Phase 3 clinical trials for up to two indications and the first commercial sale of a licensed product in the United States and selected European countries for up to two indications; potential milestone payments of up to $70.0 million upon the achievement of specified regulatory milestones, including the acceptance of our filings for regulatory approval by regulatory authorities in the United States and Europe for up to two indications; and potential milestone payments of up to $135.0 million upon the achievement of specified levels of annual net sales of licensed products. Pfizer has the right to terminate the Agreement by giving prior written notice. The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales-based milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. The Company is also eligible to receive royalties on future sales contingent upon annual net sales thresholds. In addition, the Company and Pfizer have formed a joint steering committee that will oversee and coordinate activities as set forth in the research program. The $22.5 million up-front payment was recognized over a period of 1.5 years. In May 2014, Pfizer made a $15.0 million non-refundable milestone payment to the Company. Upon the dosing of the first patient in a Phase 3 clinical trial of rivipansel, the Company will be entitled to receive a $20.0 million milestone payment under the Pfizer Agreement. During the three months ended March 31, 2015 and 2014, there were no milestone payments related to this arrangement that were earned or recognized as revenue. In February 2004, the Company entered into a research services agreement (the Research Agreement) with the University of Basel (the University) for biological evaluation of selectin antagonists. Certain patents covering the rivipansel compound are subject to provisions of the Research Agreement. Under the terms of the Research Agreement, the Company will owe to the University 10% of all future milestone and royalty payments received from Pfizer with respect to rivipansel. As of December 31, 2014, a $1.5 million milestone license fee was recorded as an accrued liability representing 10% of the $15.0 million non-refundable milestone payment that the Company received from Pfizer in May 2014. The accrued liability of $1.5 million was paid in February 2015. During the three months ended March 31, 2015, there were no additional milestones fees due to the University.

9. Research and License Agreements

In October 2011, the Company and Pfizer entered into a licensing agreement (the Pfizer Agreement) that provides Pfizer an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with sickle cell disease and for other diseases for which the drug candidate may be developed. The Company was responsible for completion of the Phase 2 trial, after which Pfizer will assume all further development and commercialization responsibilities. Upon execution of the Pfizer Agreement, the Company received an up-front payment of $22.5 million. The Pfizer Agreement also provides for potential milestone payments of up to $115.0 million upon the achievement of specified development milestones, including the dosing of the first patients in Phase 3 clinical trials for up to two indications and the first commercial sale of a licensed product in the United States and selected European countries for up to two indications; potential milestone payments of up to $70.0 million upon the achievement of specified regulatory milestones, including the acceptance of our filings for regulatory approval by regulatory authorities in the United States and Europe for up to two indications; and potential milestone payments of up to $135.0 million upon the achievement of specified levels of annual net sales of licensed products. Pfizer has the right to terminate the Agreement by giving prior written notice.

The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales-based milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. The Company is also eligible to receive royalties on future sales contingent upon annual net sales thresholds. In addition, the Company and Pfizer have formed a joint steering committee that will oversee and coordinate activities as set forth in the research program. The $22.5 million up-front payment was recognized over a period of 1.5 years. In May 2014, Pfizer made a $15.0 million non-refundable milestone payment to the Company. Upon the dosing of the first patient in a Phase 3 clinical trial of rivipansel, the Company will be entitled to receive a $20.0 million milestone payment under the Pfizer Agreement. During the three months ended March 31, 2015 and 2014, there were no milestone payments related to this arrangement that were earned or recognized as revenue.

In February 2004, the Company entered into a research services agreement (the Research Agreement) with the University of Basel (the University) for biological evaluation of selectin antagonists. Certain patents covering the rivipansel compound are subject to provisions of the Research Agreement. Under the terms of the Research Agreement, the Company will owe to the University 10% of all future milestone and royalty payments received from Pfizer with respect to rivipansel. As of December 31, 2014, a $1.5 million milestone license fee was recorded as an accrued liability representing 10% of the $15.0 million non-refundable milestone payment that the Company received from Pfizer in May 2014. The accrued liability of $1.5 million was paid in February 2015. During the three months ended March 31, 2015, there were no additional milestones fees due to the University.