Merck, known as MSD outside the U.S. and Canada, has announced that the phase III KEYNOTE-045 trial investigating the use of KEYTRUDA (pembrolizumab), the company’s anti-PD-1 therapy, in patients with previously treated advanced urothelial cancer, met the primary endpoint of overall survival (OS). In this trial, KEYTRUDA was superior compared to investigator choice chemotherapy. Based on a pre-specified interim analysis, an independent Data Monitoring Committee (DMC) has recommended that the trial be stopped early.

“The results of KEYNOTE-045 represent a major breakthrough and will be welcome news for patients dealing with previously treated advanced urothelial cancer,” said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. “We look forward to sharing the findings from this study with the medical community and with regulatory authorities around the world.”

The safety profile of KEYTRUDA in this trial was consistent with that observed in previously reported studies involving patients with advanced urothelial cancer. Results from KEYNOTE-045 will be presented at an upcoming medical meeting.

The KEYTRUDA clinical development program includes more than 30 tumor types in more than 360 clinical trials, including nearly 200 trials that combine KEYTRUDA with other cancer treatments. For genitourinary cancers, Merck has the largest immuno-oncology clinical development program in bladder cancer, with 27 trials underway involving KEYTRUDA as monotherapy and in combination, including four registration-enabling studies.

KEYNOTE-045 is a randomized, pivotal, phase 3 study (ClinicalTrials.gov, NCT02256436) evaluating KEYTRUDA monotherapy compared to investigator-choice chemotherapy (paclitaxel, docetaxel, vinflunine) in the treatment of patients with metastatic or locally advanced or unresectable (inoperable) urothelial cancer that has recurred or progressed following platinum-based chemotherapy. The co-primary endpoints are overall survival (OS) and progression-free survival (PFS); secondary endpoints are overall response rate (ORR), duration of response (DOR), and safety. The study randomized 542 patients to receive KEYTRUDA (200 mg every three weeks) or investigator-choice of paclitaxel (175 mg/m2 every three weeks), docetaxel (75 mg/m2 every three weeks), or vinflunine (320 mg/m2 every three weeks).

Bladder cancer begins when cells in the urinary bladder start to grow uncontrollably. As more cancer cells develop, they can form a tumor and spread to other areas of the body. Urothelial carcinoma, the most common type of bladder cancer, starts in the urothelial cells that line the inside of the bladder. In 2012, approximately 430,000 people worldwide were diagnosed with bladder cancer and 165,000 died from the disease. The incidence of bladder cancer is elevated in North America, Europe, North Africa, the Middle East, Australia and New Zealand.