Background: Anti-programmed cell death 1 antibodies (PD-1 Abs) are widely used for advanced melanoma, but information on the efficacy of anti-PD-1 Abs is limited in the Asian population. There remains an unmet need to improve the therapeutic effects of anti-PD-1 Ab-treatment, particularly in patients with melanoma who are refractory to anti-PD-1 Abs. The aim of this study was to evaluate anti-PD-1 Ab-treatment in combination with TM5614 (a plasminogen activator inhibitor-1 inhibitor) in patients with unresectable melanoma. Methods: The TM5614-MM study was a multicentre, open-label, single-arm, phase II clinical trial to evaluate the efficacy and safety of nivolumab in combination with TM5614 in patients with advanced, unresectable malignant melanoma recruited at seven Japanese institutes between 13 September 2021 and 31 March 2023. Patients with metastatic or unresectable melanoma previously treated with anti-PD-1 Abs were enrolled. Nivolumab 480 mg was administered intravenously every 4 weeks for 8 weeks, while TM5614 was administered orally at a dose of 120 mg (0–4 weeks) and 180 mg once daily (5–8 weeks). The primary endpoint was the overall response rate after 8 weeks of concomitant use of TM5614. Results: Thirty-nine patients were enrolled, and 34 patients were included in the anti-PD-1 Ab-refractory cohort. The overall response rate at 8 weeks was 25.9% (95% confidence interval 12.9–44.9%, P = 0.027) in 27 patients who were anti-PD-1 Ab-refractory based on investigator assessment in the protocol per set cohort. Seven patients discontinued treatment owing to progressive disease or adverse events. Treatment-related grade 3 or higher adverse events occurred in 3 of 39 patients (7.7%) in the intention-to-treat cohort. Conclusions: TM5614 in combination with nivolumab is well tolerated and effective in anti-PD-1 Ab-refractory unresectable melanoma.

Therapeutic options for treating advanced melanoma are progressing rapidly. Until six years ago, the regimen for treating advanced melanoma mainly comprised cytotoxic agents such as dacarbazine, and type I interferons. Since 2014, anti-programmed cell death 1 (PD1) antibodies have become recognized as anchor drugs for treating advanced melanoma with or without additional combination drugs such as ipilimumab. In addition, v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase inhibitors in combination with mitogen-activated protein kinase kinase (MEK) inhibitors are among the most promising chemotherapeutic regimens for treating advanced BRAF-mutant melanoma, especially in patients with low tumor burden. Since anti-PD1 antibodies are widely applicable for the treatment of both BRAF wild-type and mutated advanced melanomas, several clinical trials for drugs in combination with anti-PD1 antibodies are ongoing. This review focuses on the development of the anti-melanoma therapies available today, and discusses the clinical trials of novel regimens for the treatment of advanced melanoma.

Therapeutic options for treating advanced melanoma have progressed rapidly in recent decades. Until 6 years ago, the regimen for treating advanced melanoma consisted mainly of cytotoxic agents such as dacarbazine and type I interferons. Since 2014, anti-programmed cell death 1 (PD1) antibodies have been recognized as anchor drugs for treating advanced melanoma, with or without additional combination drugs such as ipilimumab, but the efficacies of these immunotherapies are not fully satisfactory. In this review, we describe the development of the currently available anti-PD1 Abs-based immunotherapies for advanced melanoma, focusing on their efficacy and immune-related adverse events (AEs), as well as clinical trials still ongoing for the future treatment of advanced melanoma.

It has been more than a decade since anti-PD-1 and anti-CTLA-4 antibodies were first introduced for the treatment of unresectable melanoma. The advent of these immunotherapies has dramatically transformed the treatment landscape. In recent years, anti-PD-1 antibodies have become the cornerstone of melanoma therapy, and the development of new treatment regimens has advanced rapidly in both Eastern and Western countries. However, clinical practice has revealed lower response rates in East Asian melanoma patients compared to Caucasian populations. This discrepancy may be partially attributed to T cell immune exhaustion within the tumor microenvironment, although the detailed mechanisms remain unclear. Moreover, there is currently no established treatment for BRAF wild-type melanoma that is resistant to anti-PD-1 antibodies. This review discusses the currently available therapeutic strategies for advanced melanoma and addresses the aforementioned challenges, highlighting recent efforts in both Eastern and Western regions.