The efficacy and safety of toripalimab combined with anlotinib in the first-line treatment of Chinese patients with metastatic melanoma.

9560 Background: Acral, mucosal and non-CSD melanoma are the major subtypes in Chinese melanoma patients, with poor response to antiprogrammed cell death-1 (PD-1) monotherapy. Anti PD-1 monoclonal antibodies combined with anti-angiogenesis agent have showed synergistic effects mechanically and a promising response rate. Here, we report efficacy and safety of toripalimab combined with anlotinib in Chinese patients with metastatic melanoma. Methods: Patients with metastatic acral, mucosal and non-CSD melanoma received toripalimab 240mg intravenously every 3 weeks combined with anlotinib 12 mg orally once a day for first 2 weeks every 3 weeks as first-line treatment, until disease progression or unacceptable toxicity. All patients were enrolled from the Cancer Center of Union Hospital, affiliated to Tongji Medical College of Huazhong University of Science and Technology and Hunan Cancer Hospital. Results: From January 2021 to January 2024, a total of 47 patients were enrolled in this study. Subtypes were 16 patients with acral melanoma, 21 patients with mucosal melanoma, and 10 patients with non-CSD melanoma. Average age was 59.7 ±10.1 years old. The median follow-up was 26.5 months (95% CI: 20.6, 32.4 months). Among the 46 efficacy evaluable patients, the objective response rate (ORR) and disease control rate (DCR) were 23.9% and 80.4%, respectively. Median duration of response was 14.4 months (95% CI: 7.5, 21.3). The median progression-free survival (PFS) of all 47 patients was 5.7 months (95% CI 4.2 to 7.2 months); and the median OS was 14.4 months (95% CI 7.3 to 21.5 months). The median PFS of patients with M1a stage is 24.4 months, statistically longer than M1b (5.1 months), M1c (6.6 months) and M1d (4.0 months). The median PFS of acral, mucosal and non-CSD melanoma were 6.6m, 5.1m, 5.2m respectively with no statistical difference, and these is no difference of PFS between gender and age. In terms of safety, treatment-related adverse events (TRAEs) for all grades occurred in 76.6% (36/47) of patients, and grade 3 or 4 occurred in 4.3% (2/47) of patients. The incidence of immune-related adverse reactions (irAE) was 23.4% (11/47) for all grades, the most common irAEs (≥2%) included hypothyroidism, immune-associated hepatitis and rash. Conclusions: Toripalimab combined with anlotinib displays good efficacy and well-tolerant safety profiles in the treatment of patients with metastatic melanoma. Further biomarker analysis was ongoing.