Multinational retrospective study of adjuvant therapy for stage IIIA cutaneous melanoma

Patients with resected stage IIIA melanoma have been underrepresented in clinical trials of adjuvant therapy. A retrospective study at 34 centers in Australia, Europe, and the USA compared adjuvant pembrolizumab or nivolumab (‘anti-PD1’), adjuvant dabrafenib plus trastuzumab (‘TT’), or no adjuvant therapy (‘OBS’) after resection of stage IIIA melanoma. Two-year recurrence-free survival was 79.3% with anti-PD1, 98.6% with TT, and 84.3% with OBS, whereas two-year distant metastasis-free survival was 88.4% with anti-PD1, 100% with TT, and 91.1% with OBS. Rates of grade ≥ 3 toxicities were 10.9% with anti-PD1 and 17.5% with TT; discontinuation due to toxicity occurred in 13.3% and 22.1%, respectively. The authors conclude that stage IIIA melanoma has a modest risk of recurrence. Compared with OBS, adjuvant anti-PD1 did not improve outcomes, whereas adjuvant TT did.