NEW YORK (Reuters) – Bristol Myers Squibb Co said on Monday that its blockbuster cancer immunotherapy Opdivo performed well in two separate late-stage trials, prolonging survival in previously untreated patients with kidney cancer and lung cancer.

Opdivo is one of Bristol’s top-selling drugs, but sales of the drug have slowed in recent years as it has been eclipsed by Merck & Co’s rival drug Keytruda.

New Jersey-based Bristol said Opdivo used in combination with Exelixis Inc’s drug Cabometyx significantly improved progression-free survival – a measure of the drugs’ ability to delay the disease worsening – in patients with advanced kidney cancer. That is in comparison to patients who received Pfizer’s Sutent.

It said the drug combination also improved overall survival and objective response rate – a measure of whether patients saw a reduction in tumor size. The company did not release more specific data, which it plans to present at an upcoming medical conference.

Opdivo is already approved in combination with Bristol Myers’ other immunotherapy Yervoy as an initial treatment for some kidney cancer patients. The latest trial is for a broader set of patients.

“We’re looking at another very effective combination,” Bristol Myers Chief Medical Officer Samit Hirawat said in an interview. “We certainly think its going to be a very competitive combination, compared to many others that are available.”

Merck’s Keytruda is already approved to treat advanced kidney cancer in combination with Pfizer’s Inlyta.

Bristol Myers also said that Opdivo used in combination with its other immunotherapy Yervoy improved overall survival in patients with a rare form of lung cancer called malignat pleural mesothelioma.

In the general population of previously untreated patients with advanced or metastatic malignant pleural mesothelioma, median survival is less than one year and the five-year survival rate is about 10%, Bristol Myers said.

(Reporting by Michael Erman; Editing by Cynthia Osterman)