Evaluation of patients with surgically resected high-risk melanoma receiving adjuvant therapy in routine clinical practice in the United States.
Authors: Atkins Michael B. , Julian Cristina , Secrest Matthew H. , Lee Janet , Abajo Guijarro Ana Maria , Mckenna Edward Francis 
Published: June 2021

9577 Background: The management of patients with resected stage III melanoma has changed in recent years, and real-world data on recurrence patterns and adjuvant therapy responses are scarce. This study assessed adjuvant treatment patterns and outcomes in patients with advanced melanoma by BRAF status and relapse location. Methods: Patients diagnosed with stage III advanced melanoma between January 2011 and February 2020 in the nationwide Flatiron Health electronic health record–derived deidentified database were included if they were ≥18 years, received approved first-line (1L) adjuvant therapy after January 2018 with checkpoint inhibitors (CPIs; eg, nivolumab, pembrolizumab) or targeted therapies (TTs; eg, dabrafenib/trametinib), had 6 months’ follow-up and had ≥1 visit after starting adjuvant therapy (Cohort 1). Patients from Cohort 1 were included in Cohort 2 if they had a recurrence following initiation of adjuvant therapy, and those from Cohort 2 were included in Cohort 3 if they had a distant recurrence and available documented BRAF status at any time. Time to next systemic treatment (TTNT), overall survival (OS) and relapse free survival (RFS) were estimated using Kaplan-Meier (KM) methods from adjuvant therapy start (Cohort 1), first recurrence date (Cohort 2) or first distant recurrence date (Cohort 3). Results: Cohort 1 included 447 patients receiving 1L adjuvant therapy; Cohort 2 included patients after first distant (n = 47) or local (n = 35) relapse; Cohort 3 included distant-recurrent patients with tumors that were BRAF wild type (WT) (n = 22) or BRAF mutant (n = 23). The majority of patients were aged < 65 years. Across cohorts, relative use of TTs vs CPIs was similar: Cohort 1 (4.5% vs 96%), Cohort 2 (2.4% vs 98%) and Cohort 3 (2.2% vs 98%). Nivolumab was the most frequent treatment used across cohorts (84%-88%). In Cohort 1, 1- and 2-year KM probabilities for OS, RFS and TTNT were 93.5%/83.8%, 83.2%/70.6% and 84.0%/62.4%, respectively. In Cohort 2, for patients with local recurrence, 6- and 12-month OS probabilities were 93.4% and 78.8%, respectively, which were substantially higher than those for patients with distant recurrence (64.5% and 46.9%). In Cohort 3, for patients with documented BRAF mutations, 6- and 12-month OS rates from disease recurrence were 79.1% and 49.4%, respectively, which were greater than for those with BRAF-WT tumors (54.1% and 46.3%). Conclusions: Early RFS and OS outcomes for patients with surgically resected Stage III melanoma appear comparable to those reported in randomized clinical studies. The majority of patients with advanced melanoma, including patients who experienced recurrence, initiated treatment with CPIs. OS rates were numerically greater for Cohort 3 patients with BRAF-mutant tumors. Outcomes for patients with distant recurrence after adjuvant therapy remain unfavorable and represent a continued unmet medical need.