Efficacy and safety of PD-1 monoclonal antibody combined with interferon-alpha 1b and anlotinib hydrochloride as the second-line therapy in patients with unresectable advanced melanoma: A retrospective study.

Background: Immune-checkpoint inhibitors are now used more commonly in combination than monotherapy as the first-line choice in patients with unresectable advanced melanoma. Nevertheless, for cases that progressed after the initial combination therapy, the subsequent regimen option can be very difficult. Herein, we reported the efficacy and safety of a triple combination regimen in Chinese unresectable advanced melanoma patients who had poor responses to the first-line immune therapy.

Methods: We reviewed the clinical profiles of patients diagnosed with stage IIIC-IV melanoma between June 1, 2020, and September 30, 2023. The patients who failed the prior immune therapies and received anti-PD-1 mono antibody plus interferon(IFN)-alpha 1b and anlotinib hydrochloride as the second-line therapy were enrolled in the retrospective analysis. Additionally, we examined the exhaustion of T-cells using mIHC staining in available tumor samples.

Results: Fifty-five patients were included in this study. The median follow-up period was 13.6 months. The objective response rate evaluated by the investigators was 9.1%(1CR, 4PR). The disease control rate was 47.3%. The median overall survival was 17.6 months, and the median progression-free survival was 2.8 months. The adverse events rate of any grade was 100%. Grade 3 or 4 irAEs were observed in 29.1% of cases. Multiplex immunohistochemical staining revealed an increased trend of TIM3 expression on tumor-infiltrating T cells in patients without objective response.

Conclusion: PD-1 monoclonal antibody plus interferon-alpha 1b plus anlotinib showed acceptable tolerability and anticancer benefits in Chinese metastatic melanoma patients as a second-line therapy.