Treatment related toxicities with combination BRAF and MEK inhibitor therapy in resected stage III melanoma

Combination dabrafenib (D) and trametinib (T) is an FDA approved adjuvant therapy for patients with resected stage III BRAF-mutant melanoma. We describe treatment-related toxicities with adjuvant D+T in a real-world population through a retrospective case series. The primary endpoint was development of toxicities. Results: Eighteen of the 20 patients (90%) required at least one treatment interruption due to adverse events (AEs), 11 patients (55%) required a dose reduction and 13 (65%) permanently discontinued therapy due to an AE. The nine patients who did not require dose reduction had been initiated on a lower starting dose of dabrafenib. The most common treatment-limiting AEs were recurrent pyrexia and chills (85%) and liver laboratory abnormalities (50%). The median total time on therapy was 148.5 days (range 19-383), 40.7% (range 5.2-100%) of the intended one-year duration. Conclusion: Adjuvant treatment of melanoma with combination D+T is associated with treatment-limiting toxicities in the majority of this patient group. Patients should be carefully monitored throughout therapy.