資料來源：https://www.reuters.com/article/us-health-cancer-bladder-idUSKCN18D2Q8

Pivotal trial results for Merck & Co Inc's immunotherapy drug Keytruda show that it lengthened survival by three months, or nearly 40 percent, for patients with advanced bladder cancer who had stopped responding to chemotherapy.

The data, to be presented next month at a meeting of the American Society of Clinical Oncology, follow last week's announcement that rival drug Tecentriq, from Roche Holding AG, did not improve survival when used as a second-line treatment for bladder cancer in a trial.

The Merck drug is awaiting U.S. Food and Drug Administration approval, but Tecentriq was approved by the agency last year, contingent on verification of its clinical benefit. Roche, in an emailed statement, said it plans to discuss the data with health authorities but did not disclose the timing for the discussions. According to the FDA approval letter, the company has until December to submit the full trial data to the agency.

Merck filed in February for FDA approval of Keytruda for both initial and secondary treatment of advanced urothelial cancer, the most common type of bladder cancer. Keytruda is already approved for treating melanoma, lung cancer, head and neck cancer and Hodgkin lymphoma.

Merck announced in October that the second-line bladder cancer study met its main goal and was stopped early. The company is currently enrolling patients in a phase three trial of Keytruda, combined with chemotherapy, as an initial treatment for bladder cancer.

In addition to Tecentriq's approval for bladder cancer patients whose disease has stopped responding to chemotherapy, the FDA last month approved the Roche drug as an initial treatment for people with a specific type of advanced bladder cancer and in people whose cancer progressed despite at least one prior platinum-containing chemotherapy.

The agency has also granted contingent approval to AstraZeneca Plc's Imfinzi, Bristol-Myers Squibb's Opdivo and Bavencio, developed by Pfizer Inc and Merck KGaA, as second-line bladder cancer treatments.

All five drugs are part of a new class of treatments designed to unleash the body's immune system to fight cancer by interfering with proteins known as PD-1 or PD-L1 that help malignant cells evade immune attack.

Merck said data from an open-label Phase 3 trial of 542 advanced bladder cancer patients showed median survival of 10.3 months for Keytruda patients and 7.4 months for patients given second-line chemotherapy. The study's median follow-up was 18.5 moAfter 18 months, 36 percent of Keytruda patients were alive, compared with 20.5 percent of chemotherapy patients, according to research published by ASCO.

The study did not detect a difference in the length of time patients lived without their disease getting worse.

Severe side effects were reported in 16.5 percent of the Keytruda patients, compared with nearly half of the chemotherapy group.

(Reporting By Deena Beasley; Editing by Bill Rigby and David Gregorio)