Drug or biologic? An Eli Lilly lawsuit could impact weight loss drug compounders
By Nicole DeFeudis
November 22, 2024
Eli Lilly and Novo Nordisk have filed dozens of lawsuits against compounding pharmacies marketing their own versions of popular weight loss and diabetes drugs. A new legal strategy could put Lilly one step ahead of compounders, if it’s successful.
The case may come down to one amino acid.
Lilly filed a lawsuit in September against the FDA and the Department of Health and Human Services, arguing that its next-generation “triple G” agonist retatrutide should be reclassified as a biologic, as opposed to a drug. Retatrutide’s classification has “significant implications” for Lilly, the company argued in a complaint, including which regulatory pathway the company would take, what commercial rules it’d be subject to, the potential length of retatrutide’s exclusivity, and — perhaps most importantly — whether it could be compounded.
“I believe that’s the primary motivation behind this,” said Mark Boesen, an attorney and former compounding pharmacist. Boesen has been involved with amicus, or “friend of the court,” briefs in lawsuits brought by Novo Nordisk and Eli Lilly over GLP-1 compounding, and is currently representing a med spa in a GLP-1-related case brought by Eli Lilly earlier this month.
Eli Lilly’s tirzepatide was on the FDA’s shortage list for nearly two years, opening the door for compounders to produce their own, often cheaper versions of Lilly’s brand-name Mounjaro for diabetes and Zepbound for weight loss. The drug’s shortage status is still up in the air, after the FDA faced legal pressure from a compounding trade group to put it back on the shortage list. If retatrutide is approved, Boesen said it may be in a similar position.
“If history is a guide, this thing’s going to be in short supply very, very quickly,” Boesen said of retatrutide.
Meanwhile, Eli Lilly and its GLP-1 rival Novo Nordisk have argued that compounded weight loss products may not be as safe as brand-name versions, and both companies have asked the FDA to determine that their GLP-1 products are too complex to be reproduced by a compounder. Eli Lilly asked the agency in January to classify retatrutide as a biologic, which would make it off limits to compounders.
The FDA rejected Lilly’s request, instead classifying retatrutide after determining it did not meet a requirement of being “greater than 40 amino acids in size.”
Lilly argued in its complaint that retatrutide consists of 41 amino acids, therefore meeting the requirement and making the FDA’s decision “arbitrary, capricious, and not in accordance with law.” The company asked the Indiana federal court to toss the FDA’s decision, and require the agencies to designate retatrutide as a biologic.
“I think the primary reason, if not the most significant reason, is creating a barrier for pharmacies to compound this medication if it goes into a shortage situation,” Boesen said.
Lilly declined to comment on its legal strategy, with a spokesperson stating that “retatrutide qualifies as a biologic under the governing statute.”
The FDA said it does not comment on pending litigation, and HHS did not respond to a request for comment as of press time.
Why is Lilly talking about the Chevron case?
In its argument, Lilly cited the Supreme Court’s recent decision in Loper Bright, also known as the Chevron case, which eliminated a longstanding legal doctrine that deferred to federal agencies on interpreting federal law.
“Under the Supreme Court’s recent Loper Bright decision, determining what falls within the statutory definition of ‘biological product’ is an interpretative question that courts, rather than the agency, must ultimately resolve,” Lilly wrote.
Andrew Ittleman, an attorney who has advised compounders on GLP-1-related matters, said Lilly’s case “is very relevant to the times that we’re in.”
“This case, five or six years ago, is probably unheard of, simply because I don’t think there would be a challenge to an FDA interpretation of a regulation where the issue is so squarely within the FDA’s jurisdiction,” he said.
The compounding battle wages on
Regardless of the outcome of Lilly’s case, Ittleman thinks the classification of products as a drug or a biologic will continue to be the “billion-dollar question.”
“The manufacturers are going to be incentivized to ensure that their GLP-1s meet the standard of a protein and therefore meet the standard of biologics, so that the compounders can’t be in that world anymore,” he said.