Pfizer and GSK have entered into an agreement to explore the anti-cancer efficacy and the safety of GSK’s trametinib (GSK1120212) combined with Pfizer’s palbociclib (PD-0332991) in a Phase I/II study (Study 200344) in patients with advanced/metastatic melanoma.

The study is a dose-escalation, open-label study designed to determine the recommended combination regimen (RCR) for trametinib plus palbociclib in patients with melanoma. The study will also evaluate the effect of the combination on tumor biomarkers, safety and anti-cancer activity in patients with BRAFV600 wild type melanoma, including those with NRAS mutations. The two companies will collaborate on the study, which GSK will conduct. Financial terms of the agreement were not disclosed.

Trametinib, a reversible inhibitor of MEK1 and MEK2, is approved by the FDA as Mekinist for the treatment of adult patients with unresectable or metastatic melanoma with BRAF V600E or V600K mutation as detected by an FDA-approved test. Mekinist is not indicated for the treatment of patients who have received a prior BRAF inhibitor therapy.

Palbociclib is an investigational oral and selective inhibitor of cyclin dependent kinases (CDK) 4 and 6. In April 2013, palbociclib received Breakthrough Therapy designation by the FDA for the potential treatment of patients with breast cancer. Palbociclib is not approved for any indication in any markets.