Real-world efficacy and safety data for dabrafenib and trametinib combination therapy in Japanese patients with BRAF V600 mutation-positive advanced melanoma

We conducted a retrospective investigation of the efficacy and safety of dabrafenib and trametinib combination therapy in Japanese patients with BRAF V600 mutation-positive advanced melanoma in real-world clinical practise. The study analyzed 50 patients who received dabrafenib and trametinib combination therapy for BRAF V600 mutation-positive advanced melanoma in our hospital (26 men and 24 women, aged 21–86 years, inclusive; median age, 53 years). The response rate was 72.3%, with complete response (CR) achieved in eight cases (17.0%), partial response in 26 (55.3%), stable disease in nine (19.1%) and progressive disease in four (8.5%). Median progression-free survival (PFS) was 12 months, and median overall survival (OS) was 23 months. Disease progression occurred in 29 of the 50 patients during the study period, and 25 patients died. Baseline lactate dehydrogenase and the number of organs with metastasis were important predictive factors for PFS and OS, and CR to combination therapy was a predictive factor for long-term remission. Adverse events occurred in 88% of cases; 16% were grade 3 or worse. The adverse events observed in 50% of more of patients were rash (56%) and pyrexia (52%). The efficacy of dabrafenib and trametinib combination therapy in Japanese patients was similar to that reported in global studies, and the same adverse events were generally reported; however, rash tended to occur more frequently in the patients in our study.