Dr Patel on the Safety of Pembrolizumab Plus ADT in Salivary Gland Cancer

“We didn’t see any increased safety concerns. We saw patients develop immune-related toxicities that we expect with pembrolizumab. Secondly, we saw toxicities that we would expect with goserelin as well, such as hot flashes. However, the frequency of the AEs was not worse than what we would expect with either of the drugs alone.”

Manish Patel, DO, a medical oncologist at the University of Minnesota Health and an associate professor of medicine in the Division of Hematology, Oncology and Transplantation in the Department of Medicine at the University of Minnesota Medical School, discussed the toxicity profile of androgen deprivation therapy (ADT) in combination with pembrolizumab (Keytruda) for the treatment of patients with advanced-stage, androgen receptor–positive salivary gland cancer, as seen in the phase 2 BTCRC HN17-111 trial (NCT03942653).

Patel highlighted that the research did not reveal any increased safety concerns, noting that patients developed immune-related toxicities expected with pembrolizumab alongside standard adverse effects (AEs) associated with goserelin, such as hot flashes. He explained that although 3 patients discontinued pembrolizumab due to toxicity concerns, these patients continued to receive ADT. Notably, 1 patient each discontinued this agent due to Stevens-Johnson syndrome, neurotoxicity, and pneumonitis. Patel emphasized that the frequency of these observed AEs was not worse than what would be expected with either drug administered alone, confirming the relative safety of the combined regimen within the study population.

Overall, the most common grade 3/4 AEs seen with the combination included diarrhea and skin rash (10.5% each); as well as adrenal insufficiency, increased creatine phosphokinase levels, hypoxia, decreased lymphocyte counts, neurotoxicity, pneumonitis, and weight loss (5.3% each).

Disclosures: Patel reported that the study was funded by Merck, Sharpe and Dohme and supported by TerSera Therapeutics, LLC. Patel’s disclosures unrelated to this study include receiving research funding/consultant fees from AstraZeneca and serving on the Bayer advisory board.