The company is conducting the Phase 1/2 trial in collaboration with the Melanoma Research Foundation Breakthrough Consortium (MRFBC).
MRFBC member, the Abramson Cancer Center of the University of Pennsylvania hematology oncology division chief and melanoma program leader Lynn Schuchter said, "Preclinical evidence suggests that the PI-3 kinase pathway may contribute to this resistance, and we are therefore excited to begin this study."
The Phase 1 portion of the trial will evaluate the safety and tolerability of PX-866 in up to 36 patients in combination with twice daily oral administration of vemurafenib.
A dose-escalation design will be used to evaluate three dose levels of PX-866 with up to two dose levels of vemurafenib to find out the maximum tolerated or recommended dose of both PX-866 and vemurafenib to be used in Phase 2.
The Phase 2 portion will compare anti-tumor activity and safety of PX-866 and vemurafenib at recommend doses with vemurafenib alone administered at the approved dose.
The primary endpoint of Phase 2 trial enrolling 110 patients is progression-free survival.