Real-world outcomes of patients with resected stage III melanoma treated with adjuvant therapies.

Abstract

Both immunotherapy (IO) and targeted therapy (TT) are used as adjuvant (adj) treatment for stage III melanoma, however, data describing real-world outcomes are limited. In addition, a significant proportion of patients relapse, for whom best management is unclear. The aim of our study was to assess the efficacy, and safety of adj anti-PD1 IO and TT in a real-world cohort of patients with resected stage III melanoma, and further delineate patterns of recurrence and treatment strategies. We retrospectively analyzed 130 patients who received adj therapy (100 anti-PD1 IO and 30 TT). At a median follow-up of 30 months, median relapse-free survival (RFS) was 24.6 (95% CI, 17-not reached [NR]) versus 64 (95% CI, 29.5-NR) months for the TT and IO groups, respectively (p = 0.26). Median overall survival (OS) was NR for either subgroup. At data cutoff, 77% and 82% of patients in TT and IO arms were alive. A higher number of grade ≥3 treatment-related adverse events (AEs) were noted in the IO group (11% vs. 3%), however, a higher proportion of patients permanently discontinued adj therapy in the TT group (43% vs. 11%) due to toxicity. Strategies at relapse and outcomes were variable based on location and timing of recurrence. A significant number of patients who relapsed after adj IO received a second round of IO. Among them, patients who were off adj IO at relapse had superior second median RFS (mRFS2), compared to those who relapsed while on adj IO; mRFS2 was NR versus 5.1 months (95% CI, 2.5-NR), respectively, p = 0.02. In summary, both TT and IO yielded prolonged RFS in a real-world setting, however, longer follow-up is needed to determine any potential OS benefit. Adj therapy, particularly TT, may not be as well tolerated as suggested in clinical trials, with lower completion rates (59% vs. 74%) in a real-life setting. Overall, patients who relapse during adj therapy have poor outcomes, while patients who relapse after discontinuation of adj IO therapy appear to benefit from IO re-treatment.