Long-term overall survival of patients treated with BRAF inhibitors, dabrafenib and trametinib

March 1, 2016

Abstract

Purpose
To report the overall survival (OS) and clinical characteristics of BRAF inhibitor–naive long-term responders and survivors treated with dabrafenib plus trametinib in a phase I and II study of patients with BRAF V600 mutation–positive metastatic melanoma.

Methods
BRAF inhibitor–naive patients treated with dabrafenib 150 mg twice daily plus trametinib 2 mg daily (the 150/2 group) from the non–randomly assigned (part B) and randomly assigned (part C) cohorts of the study were analyzed for progression-free and OS separately. Baseline characteristics and factors on treatment were analyzed for associations with durable responses and OS.

Results
For BRAF inhibitor–naive patients in the 150/2 groups (n = 78), the progression-free survival at 1, 2, and 3 years was 44%, 22%, and 18%, respectively, for part B (n = 24) and 41%, 25%, and 21%, respectively, for part C (n = 54). Median OS was 27.4 months in part B and 25 months in part C. OS at 1, 2, and 3 years was 72%, 60%, and 47%, respectively, for part B and 80%, 51%, and 38%, respectively, for part C. Prolonged survival was associated with metastases in fewer than three organ sites and lower baseline lactate dehydrogenase. OS at 3 years was 62% in patients with normal baseline lactate dehydrogenase and 63% in patients with a complete response.

Conclusion
Dabrafenib plus trametinib results in a median OS of more than 2 years in BRAF inhibitor–naive patients with BRAF V600 mutation–positive metastatic melanoma, and approximately 20% were progression free at 3 years. Durable responses occurred in patients with good prognostic features at baseline, which may be predictive.

Source:

Overall Survival and Durable Responses in Patients With BRAF V600–Mutant Long, Long, GV, et al. Metastatic Melanoma Receiving Dabrafenib Combined With Trametinib. Published online before printJanuary 25, 2016, doi:10.1200/JCO.2015.62.9345 http://www.melanoma.org.au/research/research-blog/...