U.S. regulators approved Bristol-Myers Squibb Co. ’s advanced lung cancer drug Opdivo, the latest of a string of events that has focused efforts on using the immune system to battle the disease. 

The action by the U.S. Food and Drug Administration came three months ahead of the agency’s deadline for reviewing the drug and just two months after a clinical trial of Opdivo was stopped early because of a significant improvement in survival. Lung cancer is the leading cause of cancer death in the U.S.

“This approval will provide patients and health care providers knowledge of the survival advantage associated with Opdivo and will help guide patient care and future lung-cancer trials,” Richard Pazdur, head of hematology and oncology products at the FDA, said.

“This is an important day for cancer patients and an important day for Bristol-Myers,” said Giovanni Caforio, the company’s chief operating officer and chief-executive officer-designate. Studies showed Opdivo has “the ability to nearly double the survival rate” for patients, “which really says it can become the standard of care for this disease,” Dr. Caforio said.

The approval amounts to an expanded indication for Opdivo, which was first approved for the market in December for patients with advanced melanoma, a skin cancer. The company plans to price the drug at about $12,500 a month, or $150,000 for patients who stay on it for a year. That is the same price as Bristol-Myers charges for the melanoma treatment.

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