Real-world outcomes of Asian patients with advanced BRAF-mutant melanoma treated with first-line BRAF/MEK inhibitors, anti-PD-1 monotherapy, or combination of nivolumab plus ipilimumab: A multicenter retrospective study in Japan (B-CHECK-RWD study).

e21553 Background: The systemic treatment for advanced BRAF-mutant melanoma includes BRAF/MEK inhibitors (BRAF/MEKi), anti-PD-1 monotherapy (aPD1), and the combination of nivolumab plus ipilimumab (NIVO/IPI). Several studies have demonstrated favorable survival benefits for those treated with immunotherapy upfront. Most of these studies, however, were conducted among Caucasian-dominant cohorts; evidence for Asian patients is limited. Therefore, our objective was to assess the efficacy of first-line therapies for Asian patients in a real-world setting. Methods: We retrospectively collected the clinical data of Asian patients with advanced BRAF-mutant melanoma treated with first-line BRAF/MEKi, aPD1, or NIVO/IPI from 26 institutions in Japan. Clinical outcomes were determined by assessing the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) by first-line therapies. Kaplan‐Meier curves and log‐rank tests, as well as multivariable Cox proportional hazard models were used to estimate survival probabilities. Results: We identified 316 Asian patients treated with first-line BRAF/MEKi (n = 224), aPD1 (n = 59), or NIVO/IPI (n = 33) between 2016 and 2021. At baseline, the median age of the patients in each treatment arm was 63, 62, and 54, respectively (p = 0.053). The ORR in the first-line therapy was 69%, 29%, and 27%, respectively (p < 0.001). With a median follow-up of 18.9 months, the median PFS was 16.2, 5.6, and 6.4 months (p = 0.001); and the median OS was 36.9, 37.9 months, and not reached (p = 0.386), respectively. In a multivariable analysis, the predictive factors of short PFS were first-line therapy with aPD1 (HR, 2.44; 95%CI, 1.70-3.50, p < 0.001) or NIVO/IPI (1.73; 1.06–2.83, p = 0.029), BRAF V600K (p = 0.031), ECOG PS ≥2 (p = 0.011), elevated lactate dehydrogenase (LDH) levels (p = 0.001), and M1a/M1c/M1d stages (p = 0.036/ < 0.001/ < 0.001, respectively). Predictive factors of short OS were BRAF V600K (p = 0.042), ECOG PS ≥2 (p = 0.001), elevated LDH levels (p < 0.001), and M1c/M1d stages (both p < 0.001). The OS did not differ significantly by first-line therapies between BRAF/MEKi, aPD1 (1.52; 0.98–2.34, p = 0.061), and NIVO/IPI (0.63; 0.31–1.27, p = 0.194). Conclusions: Although upfront NIVO/IPI showed the longest OS numerically, its superiority over BRAF/MEKi in Asian patients seems to be modest compared with Caucasian patients. Because upfront BRAF/MEKi showed an OS that was comparable with that of aPD1, BRAF/MEKi remains an active first-line therapy option, especially for those who are not amenable to take the high risk of immune-related toxicities.