Verastem Oncology with Breakthrough Therapy for Defactinib in Ovarian Cancer

Results of Early Trial Demonstrate 70% Overall Response Rate (ORR) in Patients with KRAS Mutant Tumors, 44% ORR in KRAS Wild-Type Tumors and 52% ORR in All Evaluable Patients with a Favorable Safety Profile.

Verastem (also known as Verastem Oncology), a biopharmaceutical company committed to advancing new medicines for patients battling cancer, announced that the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation for the combination of its investigational RAF/MEK inhibitor VS-6766, with defactinib, its FAK inhibitor, for the treatment of all patients with recurrent low-grade serous ovarian cancer (LGSOC) regardless of KRAS status after one or more prior lines of therapy, including platinum-based chemotherapy.

“Patients with low-grade serous ovarian cancer urgently need better solutions due to low response rates and tolerability issues associated with current therapies,” said Melissa Aucoin, CEO of the National Ovarian Cancer Coalition. “A Breakthrough Therapy designation in this disease is a significant step forward for the women who often, at a relatively young age, start a lengthy battle with this highly recurrent and impactful disease.”

The combination of VS-6766 with defactinib is being evaluated in the ongoing investigator-initiated Phase 1/2 FRAME trial. In the most recent read-out from the FRAME LGSOC cohort (n=24), the overall response rate (ORR) is 52% (11 of 21 response evaluable patients), with KRAS mutant ORR at 70% (7 of 10 response evaluable patients), KRAS wild-type ORR at 44% (4 of 9 response evaluable patients) and KRAS status undetermined ORR at 0% (0 of 2 response evaluable patients). The most common side effects seen in the study were rash, creatine kinase elevation, nausea, hyperbilirubinemia and diarrhea, most being NCI CTC Grade 1/2 and all were reversible. Several patients have been on therapy for more than one year, indicating the potential for a long duration of benefit.

“Breakthrough Therapy designation will facilitate our efforts to verify the robust and durable response and compelling safety profile of VS-6766 with defactinib that we have seen in patients with LGSOC and potentially bring a new therapy to these patients as quickly as possible,” said Brian Stuglik, CEO of Verastem Oncology. “The majority of LGSOC is RAS pathway-driven, and we are committed to exploring the potential for VS-6766 as a backbone therapy across RAS pathway-driven solid tumors.”