Kari Kendra, Shay Bellasea, Zeynep Eroglu, Siwen Hu-Lieskovan, Katie M. Campbell, William E. Carson, David A. Wada, J.A. Plaza, Gino K. In, Alexandra Ikeguchi, John Hyngstrom, Andrew S. Brohl, Bartosz Chmielowski, Nikhil I. Khushalani, Joseph Markowitz, Marcus Monroe, Carlo M. Contreras, Tawnya L. Bowles, K. Norman, Egmidio Medina, Cynthia R. Gonzalez, Ignacio Baselga-Carretero, Ivan Perez Garcilazo, Agustin Vega-Crespo, Jia Ming Chen, Nataly Naser Al Deen, Sapna P. Patel, Kenneth F. Grossmann, Vernon K. Sondak, Elad Sharon, James Moon, Michael C. Wu, Antoni Ribas
The phase 2 SWOG S1512 trial ( NCT02775851 ) was designed to evaluate the response to pembrolizumab (anti-PD-1) in individuals with desmoplastic melanoma. Here we report the results of cohort A of the trial, evaluating the pathological complete response (pCR) rate of neoadjuvant PD-1 blockade in surgically resectable desmoplastic melanoma. Secondary endpoints included clinical response rate, overall survival and toxicities. Twenty-eight eligible individuals with resectable desmoplastic melanoma received intravenous pembrolizumab (200 mg) every 3 weeks three times, followed by excision. Tissue samples before treatment, at 3-5 weeks after treatment initiation and at the time of surgery were reviewed. The primary endpoint of pCR rate by local pathological review was 71% (95% confidence interval, 51-87%; P < 0.001), which met the prespecified endpoint. There were two (7%) grade 3 treatment-related adverse events. At three years of follow-up, four participants have died, none known to be from melanoma or adverse events. In conclusion, neoadjuvant pembrolizumab in individuals with resectable desmoplastic melanoma results in a high pCR rate with acceptable safety profile. Clinicaltrials.gov: NCT02775851 .