Vitiligo associated with survival in patients receiving Keytruda for metastatic melanoma

Source: Healio.com/dermatology, October 2015

The onset of vitiligo may be associated with clinical benefit in patients with metastatic melanoma who were treated with Keytruda, according to study results recently published in JAMA Dermatology.

Researchers in France conducted a prospective study of patients with metastatic melanoma from Jan. 1, 2012 to Sept. 24, 2013, at the Cancer Campus of Gustave Roussy Institute. The patients had confirmed diagnosis of unresectable stage III or IV melanoma and had received Keytruda (pembrolizumab, Merck) according to a phase 1 protocol. Data were collected and analyzed.

Objective tumor response regarding the occurrence of vitiligo in patients receiving treatment of pembrolizumab was the primary outcome. Kaplan-Meier product-limit method was used to estimate the correlation between vitiligo occurrence and overall survival.

Seventeen patients (25%) developed vitiligo during pembrolizumab treatment. A higher occurrence of vitiligo was associated with an objective (complete or partial) response to treatment (12 of 17 patients vs. 14 of 50 patients; P = .002). The median time to onset of vitiligo was 126 days from start of treatment.

In final follow-up measurements of the patients who developed vitiligo, three had a complete tumor response to treatment, nine had a partial response, three had stable disease and two had progressive disease.

The study had a median follow-up of 441 days, with all patients who developed vitiligo still alive. Vitiligo did not develop in the 22 patients who died at final follow-up.

“Our results suggest that vitiligo could be a clinically visible immune-related event associated with clinical benefit in the context of pembrolizumab treatment,” the researchers concluded. “Better understanding of immunity against melanocytes in melanoma, which clinically manifest as vitiligo, might contribute to identification of other targets for immunotherapy against melanoma.” — by Bruce Thiel