U.S. FDA approves Roche's immunotherapy for bladder cancer

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By Toni Clarke and Natalie Grover

May 18 (Reuters) - Roche Holding AG (LSE: 0QOK.L - news) won earlier-than-expected U.S (Other OTC: UBGXF - news) . approval on Wednesday for its bladder cancer drug Tecentriq, the company's first entry in a new class of cancer drugs that work by harnessing the body's own immune system.

Tecentriq is the first new drug to treat patients with the most common form of bladder cancer approved by the U.S. Food and Drug Administration in 30 years, and the first in a class known as PD-L1 inhibitors which help prevent cancer cells from evading the immune system.

PD-L1 drugs and their close cousins, PD1-inhibitors, are considered one of the most promising areas of cancer research. The FDA has already approved PD1-inhibitors made by Bristol-Myers Squibb Co's and Merck (Jakarta: 28586808.JK - news) & Co in a variety of cancers. AstraZeneca Plc (NYSE: AZN - news) is also developing a PD-L1 inhibitor for bladder cancer.

Tecentriq, known also as atezolizumab, is approved to treat patients with advanced or metastatic bladder cancer whose disease worsened within a year of receiving chemotherapy. Roche is also studying it to treat other cancers. Analysts expect the drug could generate sales of $2.8 billion by 2020 according to Thomson Reuters (Dusseldorf: TOC.DU - news) data.

Roche, the world's biggest maker of cancer drugs, is counting on Tecentriq to offset competition from cheaper "biosimilar" versions of its older medicines.

Bladder cancer is the fifth most commonly diagnosed cancer in the United States, according to the Bladder Cancer Advocacy Network.

In a clinical trial of 310 patients, 14.8 percent experienced at least a partial shrinkage of their tumors, an effect that lasted from more than two months to nearly 14 months, the FDA said in a statement. In patients whose cancer cells expressed the PD-L1 protein, 26 percent experienced a tumor response, compared with 9.5 percent of patients who were classified as "negative" for PD-L1 expression.

"The greater effect in those who were classified as "positive" for PD-L1 expression suggests that the level of PD-L1 expression in tumor-infiltrating immune cells may help identify patients who are more likely to respond to treatment with Tecentriq," the FDA said.

The agency also approved a test, the Ventana PD-L1 assay, to detect PD-L1 protein expression levels to help doctors determine which patients might benefit the most from treatment. The test is made by Ventana Medical Systems.

The FDA gave Tecentriq accelerated approval based on its ability to shrink tumors, a so-called "surrogate" endpoint that can reasonably be predicted to result in a clinical benefit. The company will need to conduct studies to confirm that hypothesis.

(Reporting by Toni Clarke and Natalie Grover, Editing by Sriraj Kalluvila and Tom Brown)