The run of US approvals for Bristol-Myers Squibb’s immunotherapy Opdivo has hit a stumbling block after US regulators refused to approve the drug’s use in patients with advanced melanoma carrying a specific genetic mutation.

BMS is seeking to expand the drug’s scope as a monotherapy for melanoma to include carrying previously untreated patients with BRAF wild-type and BRAF V600 mutation positive metastatic forms of the disease. 

Last week the US Food and Drug Administration issued a green light for Opdivo (nivolumab) in the BRAF wild-type indication, but issued a complete response letter for the BRAF V600 mutation-positive group, asking for more information for this patient population.

The drugmaker said it is working to evaluate the FDA’s request and will “continue to work closely with the agency to determine whether additional data, currently under review, adequately addresses these comments”.

A separate supplemental filing for the drug as a single agent and in combination with Yervoy (ipilimumab) in patients with previously untreated advanced melanoma is currently undergoing a priority review in the US with a target action date of January 23. Data for Opdivo monotherapy in both BRAF wild-type and BRAF V600 mutation positive advanced melanoma was included as part of this application, BMS noted.

The drug is has already racked up approvals as: a single agent for BRAF V600 wild-type unresectable or metastatic melanoma; as monotherapy for unresectable or metastatic BRAF V600 mutation-positive melanoma and disease progression following treatment with Yervoy and a BRAF inhibitor; in combination with Yervoy for BRAF V600 wild-type, unresectable or metastatic melanoma; for the treatment of metastatic non-small cell lung cancer with progression on or after platinum-based chemotherapy; and for the treatment of patients with advanced renal cell carcinoma who have received prior anti-angiogenic therapy.