US regulators need more time to reach a decision on whether to approve Bristol-Myers Squibb’s Opdivo as a first-line treatment for advanced melanoma following the submission of extra clinical data.

The company said it has taken the opportunity to submit more data from the Opdivo (nivolumab) clinical trial program to ensure the broadest data set, irrespective of BRAF status, is included in the assessment.

Originally the US Food and Drug Administration was expected to make a decision by the end of August, but because the new data constitutes a “major amendment” to the file, the review time has been extended until November 27.

The PD-1 checkpoint inhibitor was first approved in the US in December for previously treated patients advanced melanoma, followed by a green light in March for advanced lung cancer.

Analysts believe the drug could pull in peak annual sales of $5 - $7 billion.