Nov 24 (Reuters) - Bristol-Myers Squibb Co said the U.S. Food and Drug Administration had approved the expanded use of its cancer drug, Opdivo, to treat an additional form of advanced skin cancer.

Opdivo, first approved in December 2014, raked in worldwide revenue of $467 million in the nine months ended Sept. 30.

The drug has been approved for five other indications in the past 12 months.

The company said on Tuesday the approval allows for the drug's use in patients with a previously untreated, advanced form of melanoma and is based on data from a late-stage study comparing the drug with chemotherapy.

Opdivo, already in use in patients with forms of lung cancer and with advanced melanoma who have received treatment, belongs to a promising new class of drugs designed to help the body's immune system fight cancer by blocking a protein called programmed death receptor (PD-1).

Wall Street expects such drugs to capture combined annual sales of over $20 billion by 2020.

(Reporting by Amrutha Penumudi in Bengaluru; Editing by Sriraj Kalluvila)