Phase III trial of MST 188 (vepoloxamer) fails to meet endpoint in sickle cell disease- Mast Therapeutics

Mast Therapeutics has reported top-line results from EPIC, a Phase III clinical study of its investigational new drug MST 188 (vepoloxamer) for the treatment of individuals with sickle cell disease experiencing vaso-occlusive crisis (VOC). The study did not meet its primary efficacy endpoint of demonstrating a statistically significant reduction in the mean duration of VOC (82 hours in the vepoloxamer group compared to 78 hours in the placebo group in the intent-to-treat population).

There were no statistically significant differences between treatment groups in the intent-to-treat population across the two secondary efficacy endpoints, rate of re-hospitalization for VOC and the occurrence of acute chest syndrome. Consistent with previously conducted studies, vepoloxamer was generally well tolerated with no statistically significant differences in treatment-related serious adverse events in the vepoloxamer group compared to the placebo group. No deaths occurred on the study.

These analyses are limited to just top-line data, so in the coming weeks the Company intends to review the full data set from EPIC. In addition, it plans to perform an interim analysis of the ongoing heart failure trial of vepoloxamer. However, based on the data seen to date, the company expects it will terminate all clinical development of vepoloxamer.