Rivipansel, the lead investigational drug candidate in our pipeline, is a glycomimetic drug candidate that acts as a pan-selectin antagonist, meaning it binds to all three members of the selectin family: E-, P- and L-selectin. The first potential indication for rivipansel is vaso-occlusive crisis (VOC) of sickle cell disease (SCD), a severe complication of SCD which can result in acute ischemic organ injury at one or more sites. By reducing cell adhesion, activation and inflammation that are believed to contribute to reduced blood flow through the microvasculature during VOC, rivipansel could be the first drug to interrupt the underlying cause of VOC, potentially enabling patients to leave the hospital more quickly.
In 2013, we completed a Phase 2 clinical trial in which sickle cell patients hospitalized for VOC, ranging from 12 to 60 years old, were treated with the standard of care plus either rivipansel or placebo. Patients treated with rivipansel experienced faster resolution of VOC, decreased length of hospital stay and lower use of opioid analgesics for pain management, as compared to patients receiving placebo. There was improvement in both adult and pediatric patients. Adverse event rates and severity were comparable between those treated with rivipansel and those receiving placebo.
Since the completion of our Phase 2 clinical trial, our collaborator Pfizer, Inc., has been responsible for further clinical development and the potential commercialization of rivipansel. Pfizer is now enrolling patients in a Phase 3 clinical trial (RESET) conducted under a Special Protocol Assessment with the U.S. Food and Drug Administration (FDA). Pfizer has announced that it expects to complete enrollment in this trial in the beginning of 2019, with preliminary results to be announced in the second quarter of 2019. For more information on the RESET trial, visit: resetsicklecell.com.
Under our license agreement with Pfizer, we are eligible to receive payments of up to $80 million upon the achievement of specified development milestones, up to $70 million upon the achievement of specified regulatory milestones, and up to $135 million upon the achievement of specified levels of annual net sales of licensed products. We are also eligible to receive tiered royalties, with percentages ranging from the low double digits to the low teens, based on net sales of rivipansel worldwide.
In addition to the Phase 3 program, rivipansel has received Orphan Drug status and Fast Track status from the FDA, which may lead to speedier delivery to people living with SCD. Rivipansel has not been approved for use by any health authority anywhere in the world.