Array BioPharma said a $5 million milestone was achieved after the start of Array's phase III trial in patients with low-grade serous ovarian cancer (LGSOC).

The study, called MILO (MEK Inhibitor in Low Grade Serous Ovarian Cancer), is a multinational, randomized, phase III trial and will evaluate MEK162 against physician's choice of standard chemotherapy treatments in 300 patients with recurrent or persistent LGSOC following at least one prior platinum-based chemotherapy regimen and no more than three lines of prior chemotherapy regimens. The primary endpoint is progression-free survival, and the key secondary endpoint is overall survival.

"Array is pleased to initiate its first phase III trial with the goal of helping women with low-grade serous ovarian cancer who have progressed on cytotoxics and have no other proven therapeutic options," said Ron Squarer, chief executive officer of Array BioPharma. "We also look forward to Novartis initiating both the NRAS- and BRAF-mutant melanoma pivotal studies later this year."

Array invented MEK162 and licensed worldwide rights to develop and commercialize the drug to Novartis in April 2010.  Novartis recently detailed plans to initiate phase III trials of MEK162 in both NRAS- and BRAF-mutant melanoma. All three trials will be conducted as part of the Novartis/Array co-development agreement, under which costs are capped annually and in total for Array.

There are 10 active or completed oncology clinical trials of MEK162, with plans to initiate at least six trials in 2013, including three phase III trials, one each planned in LGSOC, NRAS-mutant melanoma and BRAF-mutant melanoma.