Bristol-Myers Squibb's drug Opdivo (nivolumab) has been approved by US Food and Drug Administration (FDA) for the treatment of lung cancer.

Opdivo was approved in December to treat advanced melanoma among people who don't respond to other medicines.

Now, FDA expanded its approval for patients with advanced squamous non-small-cell lung cancer (NSCLC) whose disease progressed during or after trying chemotherapy. The drug has been authorized for people who have been treated with platinum-based chemotherapy.

The decision to approve the drug came just weeks after clinical-trial results were available. The medicine is part of a class of drugs called immunotherapies that use patients' own immune systems to fight cancer.

Opdivo reduces the cellular pathway known as PD-1 protein on cells that prevents the immune system from attacking cancer cells.

According to FDA, Opdivo was clinically tested on more than 270 people with NSCLC and was compared to another anti-cancer drug, docetaxel. The agency said that people who received Opdivo lived an average of 3.2 months longer than people given docetaxel.

Richard Pazdur, director of the agency's Office of Hematology and Oncology Products mentioned that the clinical-trial results were released by Bristol in December. The agency then decided to work with the company to make the progress of drug's early approval.

The most common side-effects of Opdivo included fatigue, shortness of breath, musculoskeletal pain, loss of appetite, cough, nausea, and constipation.

More severe adverse effects included immune reactions involving healthy organs, including the lungs, colon, liver, kidneys, and hormone-producing glands.

Shares of Bristol hit a 14-year high after the company won expanded FDA approval. According to the average estimates of eight analysts compiled by Bloomberg, Opdivo sales are expected to reach $1.7 billion next year.