BioCryst said today it halted patient enrollment in a Phase III trial of its flu drug candidate peramivir. In a statement, the company cited an interim analysis by its data monitoring committee that found just a small difference between peramivir and control groups for the primary endpoint, changes to vital signs and oxygen saturation through the 10th day.
The company also cited the recalculation of its sample size, which resulted in a group greater than the predefined futility boundary of 320 subjects.
“We are proceeding with a full analysis of unblinded data from the trial, and a final decision will be made following completion of the analysis and further discussions with our development partners; however, it is unlikely that peramivir development for US registration will continue,” William P. Sheridan, MBBS, BioCryst’s senior VP and chief medical officer, said in the statement.
The Phase III trial was designed to evaluate the efficacy and safety of 600 mg i.v. peramivir for adults, and 10 mg/kg for adolescents, hospitalized due to serious influenza. The peramivir was to be administered once-daily for five days in addition to standard-of-care, with results compared to those of standard-of-care alone.
A total 405 patients were enrolled in the overall trial population at the time of the cutoff. However, the interim analysis was conducted on just 119 of those patients enrolled in the primary efficacy population. The interim analysis evaluated the difference between the peramivir group and the control group in time to clinical resolution for the subjects enrolled to date, and estimated the sample size for the primary efficacy analysis population required to maintain adequate power, and showed statistical significance in the final study analysis.
BioCryst said it shared the DMC recommendation with the U.S. Department of Health and Human Services Biomedical Advanced Research and Development Authority (HHS/BARDA) and other development partners. BARDA had awarded BioCryst a $234.8 million contract to develop peramivir, which is already approved for use in Japan (under the name Rapiacta® ) and Korea.