Plexxikon Inc., has initiated enrollment and the first metastatic melanoma patient been dosed in a pivotal Phase 3 trial of PLX4032 (RG7204), a highly targeted oral drug designed to inhibit the BRAF cancer-causing mutation that occurs in about 50% of melanomas and about 8% of all solid tumors.

Study
The BRAF Inhibitor in Melanoma (BRIM3) trial is a randomized, controlled multicenter study expected to enroll about 700 previously untreated melanoma patients who will be randomized one-to-one with PLX4032 at a dose of 960 mg BID or dacarbazine (DTIC), a comparator drug approved for the treatment of metastatic melanoma.
Patients will be monitored throughout the study for safety and efficacy endpoints. The primary endpoint of this trial is overall survival. Secondary endpoints include duration of response, progression-free survival and best overall response rate (BORR).
Commenting on the initiation of this trial was K. Peter Hirth, PhD, chief executive officer of Plexxikon. “With some tumor shrinkage in nearly all mutation-positive melanoma patients, and 70% of patients achieving at least 30% tumor shrinkage in our most recent clinical study, PLX4032 has shown meaningful anti-tumor activity. The Phase 3 trial, with a primary endpoint of overall survival, will provide an assessment of clinical benefit of PLX4032 in a randomized, controlled study design, which should further build our registration program for this drug,” he said, adding “We are hopeful that this accelerated development program will enable us to bring this new personalized medicine to melanoma patients as quickly as possible. PLX4032 represents the first drug in Plexxikon’s promising franchise of oncology drug candidates.”
The study is being conducted at approximately 100 sites, including sites in the United States, Australia, Europe and Canada, with sites continuing to open through Q2 2010; it is part of the planned registration program for PLX4032.