PD-1 Blockade in Advanced Desmoplastic Melanoma
Posted: Friday, April 20, 2018
PD-1 or PD-L1 immune checkpoint blockade therapy appears to provide “substantial clinical benefit” in patients with advanced desmoplastic melanoma, according to a research study by Zeynep Eroglu, MD, of Moffitt Cancer Center, Tampa, Florida, and colleagues. Significant tumor response was observed in 70% of patients—one of the highest response rates reported for anti–PD-1 or PD-L1 therapies to date. The results of the retrospective review were published in Nature.
“Our findings challenge the previous school of thought that immunotherapy would offer little benefit to patients with desmoplastic melanoma due to the dense tissue architecture of these tumors. These tumors in fact have the necessary biological ingredients to be very effective targets for anti–PD-1 drugs,” stated Dr. Eroglu in a Moffitt press release.
The study identified 60 patients with advanced, nonresectable desmoplastic melanoma who received PD-1 or PD-L1 blockade therapy. Of the 42 patients with an objective tumor response, approximately half (n = 19) had a complete response. More than 2 years after beginning treatment, 74% of participants were still alive.
Researchers also noted that an immunohistochemistry analysis revealed a higher percentage of PD-L1–positive cells in the tumor parenchyma in desmoplastic melanoma versus other types of melanoma. These cells were highly associated with increased CD8 density and PD-L1 expression in the tumor-invasive margin.