An anti-PD-1 therapy significantly improves overall survival (OS) compared with chemotherapy in previously treated patients with advanced bladder (urothelial) cancer, according to a study presented at the Society for Immunotherapy of Cancer 2016 meeting (November 9-13; National Harbor, MD).
The study, conducted by Merck, randomized 542 patients with urothelial cancer to receive either Merck’s pembrolizumab (Keytruda) or investigator-choice chemotherapy. The study was designed to assess endpoints in patients with or without PD-L1 expression as well as in patients with tumors expressing PD-L1 at levels of 10% or more. The chemotherapy arm included randomly assigned doses of either paclitaxel (175 mg/m2 every 3 weeks), docetaxel (75 mg/m2every 3 weeks), or vinflunine (320 mg/m2 every 3 weeks).
Dr Roger Dansey, senior vice president of oncology late-stage development at Merck Research Laboratories, and a team of investigators found a significant improvement in OS with pembrolizumab compared with chemotherapy, with a 27% reduction in the risk of death (HR, 0.73; 95% CI, 0.59–0.91; P = .0022). The study was stopped early after the primary endpoint was achieved.
Patients treated with pembrolizumab exhibited a median OS of 10.3 months (95% CI, 8.0–11.8). In comparison, patients treated with chemotherapy exhibited a median OS of 7.4 months (95% CI, 6.1–8.3). The estimated 1-year OS rate was 43.9% for patients treated with pembrolizumab, compared with 30.7% for patients treated with chemotherapy.
The study’s findings indicate pembrolizumab could offer a new option in the treatment of bladder cancer. “These data demonstrate the potential for pembrolizumab to provide a meaningful improvement in overall survival for patients with advanced urothelial cancer who previously have received platinum-containing chemotherapy,” said Dr Dean F. Bajorin, study investigator and medical oncologist at Memorial Sloan Kettering Cancer Center.
