primary analysis of the RANDOMIZED eortc-2139/columbus-ad trial: Adjuvant encorafenib and binimetinib versus placebo in high-risk stage II BRAF-V600E/K melanoma.

PURPOSE: Stage IIB/IIC melanoma has a high risk of recurrence after resection. Combined BRAF/MEK inhibitor therapy showed benefit in resected high-risk stage III and advanced melanoma. The objective of this study was to investigate its role in stage IIB/IIC.

METHODS

Adult patients with resected stage IIB/IIC cutaneous melanoma which had a BRAF V600E/K mutation were randomized 1:1 to receive encorafenib (enco) 450 mg QD + binimetinib (bini) 45 mg BID orally for one year or placebo. The study planned to randomize 815 patients and was designed to demonstrate superiority regarding recurrence-free survival (RFS). Following a premature termination of accrual, the study was amended with safety as the primary endpoint and RFS as secondary endpoint.

RESULTS

Between June 9, 2022, and October 9, 2023, 339 patients were screened for a BRAF mutation and 110 randomized. Data cutoff was 19 Nov. 2024, after the last patient discontinued study participation. Among randomized patients, 87 (79%) had a BRAF V600E mutation, and 39 (35%) AJCC8 stage IIC. Median follow-up was 12 and 7 months for enco/bini and placebo arms, respectively. Among 54 patients who initiated enco + bini, grade ≥ 3 treatment-related adverse events (AE) occurred in 13 (24%) patients, and 18 (33%) patients had an AE leading to permanent treatment discontinuation. RFS at 12 months was 86% (95% CI: 65-95%) in the enco + bini and 70% (95% CI: 46-85%) in the placebo arm, distant metastasis-free survival at 12 months was 92% (95% CI: 77-97%) for enco + bini and 82% (95% CI: 55-93%) for placebo.

CONCLUSION

EORTC 2139 - Columbus-AD demonstrated a consistent and manageable safety profile and encouraging efficacy results for the combination of enco and bini in resected stage IIB/C BRAF V600E/K-mutated cutaneous melanomas.