Trial shows Loqtorzi improves progression-free survival in rare melanoma subtype

New research suggests an immune checkpoint inhibitor could offer a better first-line option for a hard-to-treat form of melanoma. In a phase 3 clinical trial of patients with advanced melanoma, predominantly of acral subtype, Loqtorzi (toripalimab) significantly improved progression-free survival compared with standard chemotherapy. The findings were published online on Jan. 2, 2026, in JAMA Oncology and point to a potential shift in first-line treatment for acral melanoma.

Melanoma remains one of the deadliest skin cancers worldwide. Acral melanoma is a rare subtype of melanoma that arises on the palms of the hands, soles of the feet or the nail beds. In the United States, an estimated 2,000 to 3,000 people are diagnosed with the subtype each year. In China and other parts of Asia, acral melanoma accounts for a much larger share of cases. Unlike non-acral melanoma, acral disease tends to be more aggressive and has shown poorer outcomes with immune checkpoint inhibitors, with available data largely limited to retrospective studies or subgroup analyses rather than dedicated prospective trials.

Immunotherapy has reshaped melanoma care over the past decade, and PD-1 inhibitors are now standard first-line treatment in many parts of the world. However, most pivotal trials supporting their use were conducted in Western populations dominated by non-acral disease. As a result, chemotherapy with dacarbazine has remained the only standard first-line option in China for patients without BRAF variations, despite modest response rates and short progression-free survival.

To address this gap, investigators led by Xinan Sheng, M.D., of Peking University Cancer Hospital & Institute in Beijing, conducted the phase 3 MELATORCH trial. The multicenter, open-label study enrolled patients with previously untreated stage 3 or 4 melanoma from January 2018 through July 2023.

A total of 256 patients were randomized to receive either Loqtorzi every two weeks for up to two years or dacarbazine every three weeks until disease progression or unacceptable toxicity. Nearly two-thirds of participants had acral melanoma.

After a median follow-up of nearly 12 months, Loqtorzi reduced the risk of disease progression or death by about 29% compared with dacarbazine. The progression-free survival benefit was consistent across most prespecified subgroups, including patients with acral melanoma. Blinded independent central review showed a higher objective response rate with Loqtorzi than with dacarbazine, along with a longer median duration of response, which was 13.8 months with Loqtorzi compared with 6.9 months with chemotherapy. Safety results were in line with expectations for PD-1 inhibitors.

“To our knowledge, this is the first pivotal phase 3 study to investigate the efficacy and safety of a PD-1 inhibitor in patients with previously untreated advanced melanoma predominantly of acral subtype,” the authors wrote in their paper. With nearly two-thirds of participants having acral disease, the trial showed a significant progression-free survival benefit with Loqtorzi over dacarbazine, providing what the authors describe as more direct evidence of the clinical value of first-line PD-1 inhibitor therapy in non-Western populations where acral melanoma is most common.

The authors noted several limitations, including the lack of biomarker analyses and the absence of head-to-head comparisons with other PD-1 inhibitors, which were not approved for first-line use in China when the study began. In addition, the trial was not specifically powered to assess outcomes in the acral melanoma subgroup. Even so, the findings suggest that Loqtorzi could expand the available treatment options for patients facing acral melanoma.

The study was funded by Shanghai Junshi Biosciences Co., Ltd. Loqtorzi is a PD-1 inhibitor that was FDA approved in 2023 to treat patients with nasopharyngeal carcinoma, both in combination with chemotherapy as a first-line option and as a single agent for disease that has progressed after platinum-based therapy. In the United States, Loqtorzi is marketed by Coherus Oncology.