GSK noted that trametinib has not showed clinical activity in patients who have progressed on a prior BRAF inhibitor therapy.
The EU approval is based on results from the randomized, open-label Phase III METRIC trial carried out in 322 patients with BRAF-mutant melanoma (types V600E and V600K) who were treatment-naïve or may have received one prior chemotherapy treatment in the metastatic setting.
In the Phase III trial, treatment with trametinib resulted in a statistically significant increase in progression-free survival (PFS) compared to chemotherapy, with a median PFS of 4.8 months for patients taking trametinib compared to 1.5 months for chemotherapy.
The regulatory submission of the drug to the European authorities also included a single-arm Phase II trial designed to evaluate the objective response rate, safety, and pharmacokinetics of trametinib at 2.0mg once daily in patients with BRAF V600E, V600K, or V600D mutation-positive metastatic melanoma.
In the Phase II trial, 97 patients with BRAF-mutant melanoma were split in two groups: previously treated or not treated with a BRAF inhibitor.
Safety of trametinib has been evaluated in the integrated safety population of 329 patients with metastatic melanoma.
Out of them, 211 patients were treated with trametinib for BRAF V600-mutant melanoma in a randomised, open-label Phase III trial.