Site Editor
Soo Park, MD
Soo Park, MD
Posted: Wednesday, August 20, 2025
According to Antoni Ribas, MD, PhD, of Jonsson Comprehensive Cancer Center, University of California, Los Angeles, and colleagues, patients with advanced desmoplastic melanoma showed a high response rate to single-agent anti-PD–1 inhibition but are limited by a frequency of toxicities that is numerically higher than in other populations. The outcomes of those with unresectable disease in cohort B of the single-arm phase II SWOG S1512 trial were published in the journal Nature Medicine.
Overall, the data “reinforce the use of anti–PD-1 [immunotherapy] as the preferred treatment option for this disease,” Dr. Ribas commented in an institutional press release. He continued, “It offers a less invasive, more targeted approach compared with surgery, radiation [therapy, and] combination immunotherapies, which can have more severe side effects.”
The investigators divided the study into two cohorts to evaluate the activity of pembrolizumab in patients with surgically resectable (cohort A) and unresectable (cohort B) disease. Cohort B enrolled 27 patients receiving 200 mg of the agent intravenously every 3 weeks for up to 2 years.
The complete response rate was 37%, and the post hoc objective response rate was 89%. The estimated 3-year melanoma-specific progression-free survival and overall survival rates were 84% and 96%, respectively, with one patient having died from disease progression. A total of 37% of the cohort experienced grade 3 or 4 adverse events, and 33% discontinued treatment because of adverse events.
“The promising results from this trial show that pembrolizumab can offer durable benefit for patients with a melanoma subtype that previously had no successful treatment options, and now we know that desmoplastic melanoma is among the cancers with the highest response rates to the anti–PD-1 class of cancer immunotherapies,” Dr. Ribas concluded in the press release. “This advances our understanding of exceptional responders to cancer immunotherapy, and it changes the treatment paradigm with a highly active and low toxicity treatment approach.”
Disclosure: For full disclosures of the study authors, visit nature.com.
JNCCN Spotlights
Resources
For your Patients
