Pfizer Inc.'s rivipansel failed to treat symptoms in patients suffering from a complication resulting from inherited red blood cell disorder in a late-stage study.
The phase 3 study, dubbed Reset, was evaluating the drug's efficacy, safety and time-to-discharge in children 6 and older, who were hospitalized for vaso-occlusive crises, or VOCs — a common, painful complication of sickle cell disease — and required treatment with intravenous opioids for pain management.
Sickle cell disease is caused by a mutation in the oxygen-carrying blood component called hemoglobin, resulting in the shortened life span of red blood cells.
The 345 study participants were randomized to receive rivipansel or placebo every 12 hours to a maximum of 15 doses. Patients were followed for safety for 35 days after their last dose.
The results from the study showed that the drug failed to improve the time until patients were ready to be discharged from the hospital and reduce the overall hospitalization period. The study also failed to meet its other key secondary goals, which included overall consumption and time to discontinuation of opioids.
"We recognize this is a significant setback for the [sickle cell disease] community, who are eagerly awaiting new treatment options, and we share in their disappointment," said Freda Lewis-Hall, chief patient officer and executive vice president at New York-based Pfizer.
The U.S. pharmaceutical giant said it will share additional data on efficacy and safety endpoints, which are not available at this time, at a future scientific meeting.
In addition, some patients who completed the Reset trial were able to participate in an open-label extension study and receive rivipansel for subsequent VOC episodes over an 18-month period, the company noted.
Pfizer licensed the rivipansel from GlycoMimetics Inc. in 2011. Rockville, Md.-based GlycoMimetics said in a statement that it was "surprised and deeply disappointed" by the outcome.