Lilly and FDA clash over retatrutide classification as company nears submission

Eli Lilly is preparing to file its obesity drug candidate retatrutide for approval while a legal dispute with the FDA over the drug's classification intensifies.

The agency has concluded that retatrutide does not meet the definition of a biologic, meaning the company would have to pursue a traditional new drug application rather than a biologics license application.

The filing path matters because a biologics license would grant up to 12 years of market exclusivity, compared with only five years under a standard drug application, a difference that could translate into tens of billions of dollars for Lilly.

The disagreement dates back to a September 2024 lawsuit filed by Lilly, and although the case remains unresolved, the issue is coming to a head as the submission deadline approaches.