Genentech, a unit of Swiss drugmaker Roche Holding AG, said on Monday it got approval from the U.S. Food and Drug Administration for its already approved immunotherapy drug, Tecentriq, to treat advanced bladder cancer.

Tecentriq, also known as atezolizumab, received the go-ahead under the FDA's accelerated approval program as a first-line treatment for patients with advanced bladder cancer who are not eligible for standard cisplatin chemotherapy.

The drug was earlier approved in patients with advanced or metastatic bladder cancer whose disease worsened within a year of receiving chemotherapy.

The approval, which came six months after the FDA approved Tecentriq for the treatment of non-small cell lung cancer, is a boost to the Swiss drugmaker's bid to expand indications for the drug.

Tecentriq belongs to a closely watched class of drugs called PD-1 inhibitors, which help the immune system fight cancer by blocking a mechanism that tumors use to evade attack.

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