9550 Background: Acral and mucosal melanoma were rarely seen in Caucasians but common in Asians. Previous studies revealed that acral and mucosal melanoma are more aggressive than cutaneous melanoma with a high unmet need for effective treatments. Camrelizumab plus anti-angiogenic agents have shown promising antitumor activity in previously untreated melanoma. Famitinib, a selective multiple-target tyrosine kinase inhibitor that exhibits both anti-angiogenesis and antiproliferative effects via targeting VEGFR-2, PDGFR, c-kit, FGFR and so on, combined with camrelizumab had been proven effective in multiple cancers. This study aimed to assess the antitumor activity and safety of camrelizumab plus famitinib in both immunotherapy naïve and experienced advanced mucosal or acral melanoma. Methods: This single-center, open-label phase II study recruited patients (pts) with advanced acral and mucosal melanoma. Pts who were immune checkpoint inhibitors (ICI) treatment naïve were in cohort 1, while pts experienced ICI in cohort 2. In both cohorts, pts received camrelizumab (200 mg i.v. q3w) and famitinib (20 mg po qd) until disease progression or intolerable toxicity. The primary endpoint was objective response rate (ORR) per RECIST1.1. Secondary endpoints included progression free survival (PFS), disease control rate (DCR), overall survival (OS), and safety. This analysis focused on cohort 2. Results: As of January 12, 2023, 18 pts (9 mucosal and 9 acral histology subtypes) were enrolled in cohort 2. The median age of all pts was 58 yrs (ranged 38-71 yrs); 9 pts (50.0%) were female; prevalence of mutations: BRAF (11.1%), C-KIT or NRAS (16.7% each); 38.9% received ≥2 prior treatments. All pts progressed after anti-PD-1/L1 monotherapy (27.8%) or combinational therapy (66.7%), except one progressed after 4-1BB mAb monotherapy. The combination drugs included anti-LAG-3/CTLA-4 antibodies (38.9%), oncolytic viruses (11.1%), c-kit inhibitors, chemotherapy and anti-angiogenic agents (5.6% each). The median follow-up was 7.3 months (ranged 4.6-14.7 months). At the data cutoff, 5 pts remained on treatment. 17 pts were evaluable. The ORR and DCR were 17.6% and 64.7%, including two pts with confirmed PR, and one with unconfirmed PR, all of which were acral subtype. The median PFS was 6.0 months. The median OS was not reached. Of 18 pts, the incidence of treatment-related adverse events (TRAEs) was 88.9%. The most common grade 3 TRAEs was neutrophil count decreased (11.1%). No grade 4 TRAEs and no treatment-related deaths occurred. Conclusions: Camrelizumab plus famitinib showed promising antitumor activity in ICI-experienced advanced acral and mucosal melanoma pts, and was generally well tolerated. Clinical trial information: NCT05051865 .