Bristol Myers Squibb Co said on Tuesday its blockbuster cancer immunotherapy, Opdivo, in combination with chemotherapy improved survival in patients with a type of bladder cancer in a late-stage trial.

The drug met the dual main goals of extending overall survival and helping patients live without their disease worsening, in combination with chemotherapy followed by Opdivo, in the study testing it against standard-of-care chemotherapy.

Opdivo was being studied in patients with types of urothelial carcinoma, or bladder cancer, who are eligible for standard-of-care cisplatin-based chemotherapy.

The drug, first approved in 2014, is one of the top selling treatments for Bristol Myers, with analysts forecasting $8.3 billion in sales for the year, according to Refinitiv estimates.

But the drug's sales have slowed in recent years after rival Merck & Co's Keytruda, which was approved in 2016, became the market leader in the treatment for the most common form of lung cancer. In 2017, the U.S. Food and Drug Administration approved the use of Opdivo to include the treatment of some types of bladder cancer.

It was also approved by the FDA a few years later, as an adjuvant or follow-up treatment for bladder cancer patients who are at a high risk of recurrence after undergoing radical resection.

Bladder cancer is the tenth most common form of the disease in the world, with more than 573,000 new cases diagnosed annually, according to Bristol Myers.