Verastem, Inc. announced dosing of the first patient in a new clinical trial evaluating the combination of VS-5584, its dual mTORC1/2 and PI3K inhibitor, in combination with VS-6063, the Company's lead focal adhesion kinase (FAK) inhibitor, in patients with relapsed mesothelioma. The Phase 1 open-label, dose escalation and schedule finding study is designed to assess safety, pharmacokinetics, pharmacodynamics and initial observations of clinical activity. The study is expected to enroll up to 56 patients at clinical sites in the UK and US.

VS-5584 is currently in a Phase 1 study in advanced solid tumors where the compound has been generally well tolerated and preliminary activity has been observed, including in mesothelioma. Some patients have been on study for over 6 months and the maximum tolerated dose of VS-5584 has not been reached. The combination clinical trial is supported by preclinical work demonstrating the synergistic activity of VS-6063 and VS-5584 in mesothelioma models in vitro and in vivo.

In this preclinical research, the combination of VS-6063 and VS-5584 displayed synergistic reduction in cell viability based on multiple combination analysis models. When tested in vivo for reduction of mesothelioma tumor growth, VS-6063 and VS-5584 were each active as single agents and demonstrated synergistic antitumor efficacy when used in combination.