Is the BRAF mutation still an unfavorable risk factor in patients with metastatic melanoma in the era of modern therapies?

Abstract

e21544 Background: BRAF-mutated (MUT) melanoma is characterized by specific clinical features including more aggressive biological behavior than BRAF wild-type (WT) melanoma. BRAF mutations are historically known as negative prognostic factor for to shorter overall survival (OS) in patients with stage IV disease with melanoma. Methods: Consecutive patients with unresectable or metastatic melanoma started treatment with BRAF inhibitors (BRAFi), BRAFi and MEK inhibitors (MEKi) or IT (anti-PD-1 antibody) between 1/Jan/2013 and 31/Dec/2020. Clinical factors including age, gender, primary location of melanoma, ECOG performance status, baseline LDH level, and location of metastases, response to treatment were analyzed. Survival analyses were performed using the Kaplan-Meier method, Log-rank and chi-square tests were used for comparison between groups. Data cut-off was 31/Dec/2021. Results: In total 1456 patients were enrolled. BRAF mutation was found in 723 (49.7%) patients and 733 (50.3%) patients were BRAF WT. All BRAF WT patients received first-line IT, while BRAF MUT patient received first-line treatment with BRAFi (n = 134/723, 18%), BRAFi and MEKi (n = 426, 58%) or anty-PD-1 (n = 173, 24%). BRAF MUT patients were significantly younger (median 60 vs 69; p < 0.0001), had worse ECOG (p = 0.0008), elevated LDH (p < 0.0001), had higher number of metastatic sites (p < 0.0001) and brain metastases (p < 0.0001). The estimated median OS (mOS) in BRAF WT group was 17.3 month while in BRAF MUT - 14.8 months (p = 0.33; HR = 0.94, Cl 95% 0.8-1.1). mOS in BRAF MUT group treated with BRAFi was - 10.0, while with BRAFi and MEKi combination - 14.9. BRAF WT and BRAF MUT groups treated with IT did not differ significantly in baseline characteristics. BRAF MUT group treated with IT achieved mOS of 26.2 months, while in BRAF WT 17.3 months. Conclusions: The analysis showed no differences in the median OS between BRAF MUT and BRAF WT patients with unresectable or metastatic melanoma treated with novel therapies (BRAFi-MEKi combination or IT), despite unfavorable prognostic factors in the BRAF MUT group. Moreover mOS was significantly prolonged in the BRAF MUT patients treated with IT.