Ono Pharmaceutical Co has become the first company in the world to get an approval for a PD-1 checkpoint inhibitor, as regulators in Japan gave the green light to nivolumab, developed with Bristol-Myers Squibb, as a treatment for melanoma.

The drug will be marketed as Opdivo for unresectable melanoma although Ono noted that because of the very limited number of patients treated with nivolumab in Japanese clinical trials, the firm is required to perform a "post-marketing use-results survey covering all cases until data on a certain minimum number of patients have been accumulated”.

Ono said that currently only the chemotherapy dacarbazine is available for advanced melanoma in Japan and until reimbursement is approved, it will, “based on ethical considerations,” provide access to Opdivo free of charge as soon as it is ready. The recommended dose for adults is 2 mg/kg (body weight) of nivolumab administered as an intravenous infusion every three weeks.

Gyo Sagara, Ono’s president, said the Osaka-headquartered firm is delighted to obtain approval for a drug targeting PD-1 “for the first time in the world”. The company will now seek the green light for “additional indications on ongoing development for other cancers to bring many patients Opdivo as soon as possible”.

The development of nivolumab came about through a research collaboration signed in May 2005 between Ono and Medarex, which was acquired by B-MS in 2009. As part of a pact signed with the latter in September 2011, Ono retained the rights to the drug in Japan, Korea and Taiwan, and B-MS was granted a license for the rest of the world.

Just a couple of weeks ago, B-MS stopped its Phase III study assessing nivolumab in melanoma after independent regulators found that it showed a superior survival benefit over dacarbazine. It is being studied in multiple tumour types in 35 different trials, notably for non-small cell lung cancer.

The PD-1 arena is causing huge excitement among oncologists and in April nivolumab was filed in the USA in April for melanoma through a rolling application. Just last week, Merck & Co filed its checkpoint inhibitor pembrolizumab for the skin cancer with regulators in Europe.