Dabrafenib combined with trametinib is associated with durable responses in metastatic melanoma

This study investigated the effectiveness and safety of combined treatment with dabrafenib (Tafinlar) and trametinib (Mekinist) in patients with BRAF mutated stage 3 or 4 melanoma. Researchers suggested that the combination treatment has durable (3 years or more) results.  

Patients with metastatic (spread to other parts of the body) melanoma have poorer outcomes, with a 5-year survival of 6%. New therapies are associated with more long-lasting tumor responses.

Some melanoma patients have a mutation (permanent change) in the BRAF gene. BRAF and MEK inhibitors block the BRAF and MEK proteins, reducing tumor growth. The combination of dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor) improves the survival of patients with BRAF mutated melanoma when compared to dabrafenib alone.

Treatment with BRAF inhibitors has been showing improvements in outcomes for these patients. However, studies with longer follow-up times are necessary.

The objective of this study was to investigate the effectiveness and safety of the combined treatment dabrafenib plus trametinib for a longer follow-up period (3 years).

This study included information about 423 patients with metastatic BRAF-mutated melanoma. These patients were randomly assigned to receive the combined treatment (211) or dabrafenib alone (212).

The 3-year progression-free survival (time from treatment to cancer progression) was 22% with the combination and 12% with dabrafenib alone. The 3-year overall survival (time from treatment until death from any cause) was 44% for patients in the combination group and 32% for the dabrafenib alone group.

In the group of patients with lower risk (based on factors such as normal lactate dehydrogenase levels and less than 3 sites of metastasis) the 3-year survival with the combined treatment was 62%. The 3-year survival was 25% in patients with higher risk.

In total, 97% of the patients had side effects. Of these, 48% were from the combination group. From the combination group 45% of the patients had severe side effects when compared to 38% from the dabrafenib alone group. The most common side effect in both groups was fever. Other common side effects were chills, diarrhea, vomiting, and swelling.

This study suggests that the combined treatment with dabrafenib and trametinib is associated with a durable survival (3 years or more) in patients with stage 3 or 4 BRAF-mutated melanoma, with manageable side effects.