FDA delays decision on inotersen, handing lead to Alnylam

The FDA has delayed the PDUFA date for Akcea’s hereditary TTR amyloidosis drug inotersen, handing first-mover advantage to Alnylam. Akcea suffered the setback after the FDA asked for more time to review its response to requests for information on the rare disease antisense drug.

Officials at the FDA accepted inotersen for priority review at the start of the year, setting the agency on the path to a July 6 decision. Ionis made the filing before licensing the drug to its affiliate Akcea in March. At that point, inotersen looked set to beat Alnylam’s rival TTR drug patisiran to market. That is no longer the case. 

By the time the FDA completes its review of inotersen, patisiran may already have been approved for two months. The late switch at the front of the race means Akcea has ceded a small headstart to a drug widely seen as having shone brighter than its inotersen in phase 3.

Akcea president Sarah Boyce said the FDA delayed the PDUFA date after finding it needed more time to review the company’s “responses to their standard information requests.” The biotech is working to help the FDA process its application as quickly as possible but it could be another five months before the agency rules one way or another.

Shares in Akcea fell 5% in premarket trading as investors digested the implications of the news. As well delaying the commercialization of inotersen, the setback raised the spectre of safety concerns seen during its development and doubts about Akcea’s execution of the regulatory process. 

Akcea has opportunities to dispel those doubts in the months to come. Volanesorsen, an antisense drug for lowering cholesterol, is set to go before an FDA advisory committee next week. The PDUFA date for volanesorsen is scheduled for the end of August. If all goes well, Akcea will end the year with two FDA-approved rare disease drugs.