Research and License Agreements	9 Months Ended
Sep. 30, 2019
Research And License Agreements [Abstract]
Research and License Agreement	9. Research and License Agreements In 2011, the Company and Pfizer entered into the Pfizer Agreement, which provides Pfizer an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with sickle cell disease (SCD) and for other diseases for which the drug candidate may be developed. On August 2, 2019, Pfizer announced that the pivotal Phase 3 clinical trial to evaluate the efficacy and safety of rivipansel did not meet its primary or key secondary efficacy endpoints. Pfizer’s analysis of the Phase 3 results is ongoing, and the Pfizer Agreement remains in effect, although the Company does not currently expect to receive any of the potential future milestone payments described below. Under the Pfizer Agreement, the Company was responsible for completion of the Phase 2 clinical trial of rivipansel, after which Pfizer assumed all further development and commercialization responsibilities. Upon execution of the Pfizer Agreement, the Company received an up-front payment of $22.5 million. With respect to rivipansel for the treatment of SCD, the Pfizer Agreement provides for potential development, regulatory and commercial milestone payments of up to $120.0 million in the aggregate, and for any additional indication that may be developed by Pfizer, the Pfizer Agreement provides for potential development, commercial and regulatory milestone payments of up to $65.0 million in the aggregate. The Pfizer Agreement also provides for 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 Pfizer Agreement by giving prior written notice. The Company assessed this arrangement in accordance with Topic 606 and concluded that the contract counterparty, Pfizer, is a customer. The Company identified the following performance obligations under the contract: (1) an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with SCD and for other diseases for which the drug candidate may be developed; and (2) research and development (R&D) services to develop the rivipansel compound for commercial use related to the Phase 2 clinical trial and delivery of data to Pfizer. Based on the Company’s assessment, the Company determined that the rivipansel license and R&D services are not distinct and are therefore considered as one combined performance obligation. In addition to the rivipansel license and R&D services, management also considered whether the Company’s participation in a Joint Steering Committee (JSC) constituted a promise. The JSC was formed solely for communication purposes between Pfizer and the Company relating to Pfizer’s progress in further developing rivipansel for commercial use. The Company’s involvement in the JSC is limited to attending the JSC meetings on a semi-annual basis to receive progress updates from Pfizer; Pfizer is responsible for calling and organizing the meetings. Given the minimal level of involvement by the Company, participation in the JSC is not considered a significant aspect of the arrangement and the related costs, such as employee time, are not material. Therefore, management views the Company’s participation in the JSC as administrative only and did not further evaluate its participation in the JSC in identifying the performance obligations in the Pfizer Agreement. Under the Pfizer Agreement, in order to evaluate the appropriate transaction price, the Company determined that the up-front amount constituted the entirety of the consideration to be included in the transaction price. The transaction price of the up-front fee is equal to the $22.5 million received. The fixed up-front consideration was recognized under ASC 606 based on when control of the combined performance obligation was transferred to the customer, which corresponded with the service period (through March 2013). None of the clinical or regulatory milestones have been included in the transaction price, as all milestone amounts were fully constrained. Event-driven milestones are a form of variable consideration as the payments are variable based on the occurrence of future events. As part of its evaluation of the constraint, the Company considered numerous factors, including that receipt of the milestones is outside the control of the Company and is contingent upon success in future clinical trials and the licensee’s efforts. Recognition of event-driven milestones should be recognized when the variable consideration is no longer constrained. Future event-driven milestones will be recognized when the constraint no longer applies. The Company received a $15.0 million non-refundable milestone payment in May 2014 and an additional non-refundable milestone payment of $20.0 million in June 2015. The Company did not recognize any revenue under the Pfizer Agreement during the nine months ended September 30, 2019 or 2018. Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to Pfizer and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. In evaluating the Pfizer Agreement, the Company considered that there were no significant financing components identified, no non-cash consideration was paid by Pfizer and no consideration was paid by the Company to Pfizer as part of the arrangement. The Company has entered into a research services agreement (the Research Agreement) with the University of Basel (the University) for biological evaluation of selectin antagonists. While the scope of work under the Research Agreement with the University ended in 2017, certain patents covering the rivipansel compound are subject to provisions of the Research Agreement. Under the terms of the Research Agreement, the Company owes to the University 10% of all milestone and royalty payments received from Pfizer with respect to rivipansel. There were no milestone payments due to the University for the nine months ended September 30, 2019 or 2018.

9. Research and License Agreements

In 2011, the Company and Pfizer entered into the Pfizer Agreement, which provides Pfizer an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with sickle cell disease (SCD) and for other diseases for which the drug candidate may be developed. On August 2, 2019, Pfizer announced that the pivotal Phase 3 clinical trial to evaluate the efficacy and safety of rivipansel did not meet its primary or key secondary efficacy endpoints. Pfizer’s analysis of the Phase 3 results is ongoing, and the Pfizer Agreement remains in effect, although the Company does not currently expect to receive any of the potential future milestone payments described below.

Under the Pfizer Agreement, the Company was responsible for completion of the Phase 2 clinical trial of rivipansel, after which Pfizer assumed all further development and commercialization responsibilities. Upon execution of the Pfizer Agreement, the Company received an up-front payment of $22.5 million. With respect to rivipansel for the treatment of SCD, the Pfizer Agreement provides for potential development, regulatory and commercial milestone payments of up to $120.0 million in the aggregate, and for any additional indication that may be developed by Pfizer, the Pfizer Agreement provides for potential development, commercial and regulatory milestone payments of up to $65.0 million in the aggregate. The Pfizer Agreement also provides for 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 Pfizer Agreement by giving prior written notice.

The Company assessed this arrangement in accordance with Topic 606 and concluded that the contract counterparty, Pfizer, is a customer. The Company identified the following performance obligations under the contract: (1) an exclusive worldwide license to rivipansel for vaso-occlusive crisis associated with SCD and for other diseases for which the drug candidate may be developed; and (2) research and development (R&D) services to develop the rivipansel compound for commercial use related to the Phase 2 clinical trial and delivery of data to Pfizer. Based on the Company’s assessment, the Company determined that the rivipansel license and R&D services are not distinct and are therefore considered as one combined performance obligation. In addition to the rivipansel license and R&D services, management also considered whether the Company’s participation in a Joint Steering Committee (JSC) constituted a promise. The JSC was formed solely for communication purposes between Pfizer and the Company relating to Pfizer’s progress in further developing rivipansel for commercial use. The Company’s involvement in the JSC is limited to attending the JSC meetings on a semi-annual basis to receive progress updates from Pfizer; Pfizer is responsible for calling and organizing the meetings. Given the minimal level of involvement by the Company, participation in the JSC is not considered a significant aspect of the arrangement and the related costs, such as employee time, are not material. Therefore, management views the Company’s participation in the JSC as administrative only and did not further evaluate its participation in the JSC in identifying the performance obligations in the Pfizer Agreement.

Under the Pfizer Agreement, in order to evaluate the appropriate transaction price, the Company determined that the up-front amount constituted the entirety of the consideration to be included in the transaction price. The transaction price of the up-front fee is equal to the $22.5 million received. The fixed up-front consideration was recognized under ASC 606 based on when control of the combined performance obligation was transferred to the customer, which corresponded with the service period (through March 2013). None of the clinical or regulatory milestones have been included in the transaction price, as all milestone amounts were fully constrained. Event-driven milestones are a form of variable consideration as the payments are variable based on the occurrence of future events. As part of its evaluation of the constraint, the Company considered numerous factors, including that receipt of the milestones is outside the control of the Company and is contingent upon success in future clinical trials and the licensee’s efforts. Recognition of event-driven milestones should be recognized when the variable consideration is no longer constrained. Future event-driven milestones will be recognized when the constraint no longer applies. The Company received a $15.0 million non-refundable milestone payment in May 2014 and an additional non-refundable milestone payment of $20.0 million in June 2015. The Company did not recognize any revenue under the Pfizer Agreement during the nine months ended September 30, 2019 or 2018.

Any consideration related to sales-based milestones (including royalties) will be recognized when the related sales occur as they were determined to relate predominantly to the license granted to Pfizer and therefore have also been excluded from the transaction price. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. In evaluating the Pfizer Agreement, the Company considered that there were no significant financing components identified, no non-cash consideration was paid by Pfizer and no consideration was paid by the Company to Pfizer as part of the arrangement.

The Company has entered into a research services agreement (the Research Agreement) with the University of Basel (the University) for biological evaluation of selectin antagonists. While the scope of work under the Research Agreement with the University ended in 2017, certain patents covering the rivipansel compound are subject to provisions of the Research Agreement. Under the terms of the Research Agreement, the Company owes to the University 10% of all milestone and royalty payments received from Pfizer with respect to rivipansel. There were no milestone payments due to the University for the nine months ended September 30, 2019 or 2018.