Endo presses pause on litigation after FDA assurance to sort out compounding competition by year-end

Stamp with blue ink that says "FDA Approved"
Litigation by Endo Pharmaceuticals challenges the FDA's approval of competing compounded drugs. (Olivier Le Moal/Getty Images)

Endo Pharmaceuticals’ on-again, off-again lawsuit, aimed at keeping the FDA from giving bulk compounders the ability to compete with one of its key drugs, is off again.

Endo said on Monday that it had agreed to an additional stay of its litigation against the FDA until Dec. 31, 2018, with the understanding the the agency by then will complete a review of whether vasopressin, the API in its blood pressure booster Vasostrict, should be on a list of bulk ingredients available to compounders.

"Endo reiterates its prior statement that bulk compounding of vasopressin by outsourcing facilities is inappropriate and undermines the longstanding new drug approval framework of the Federal Food, Drug, and Cosmetic Act," Matthew J. Maletta, chief legal officer of Endo, said in a statement.

Had it not been for the FDA's "best efforts commitment," Maletta said Endo would not have held off on the litigation, which has been stayed and then reopened multiples times.  

The litigation, which was filed last December by Endo subsidiary Par, is specific to vasopressin, the API in Endo’s Vasostrict, a drug that brought in about $400 million for Endo last year. However, it still has implications for other drugmakers whose drugs may be targeted by large-scale compounders for generics.

RELATED: FDA rolls out draft guidelines that narrowly define what drugs compounding pharmacies can make

In 2016, draft guidelines were released by the regulatory agency targeted at making sure a valid clinical need exists before a compounded version of an approved drug can be made for a patient. Even though a federal law said compounders shouldn’t make copies of drugs that are approved for sale, the guidelines were an attempt to refine the FDA’s interpretation of that law.

Since opening up the list to suggestions for inclusion, compounders have nominated hundreds of bulk substances in hopes of cashing in on compounded versions of them. The FDA approved vasopressin for that list last December, prompting Endo’s suit. The litigation challenges the way the FDA is approving drugs to the list of APIs, saying it violates the provisions of introducing new drugs to the market.

In July, New York-based compounder Athenex intervened in Endo’s litigation and in August announced it intended to introduce a line of compounded vasopressin to the market.

As the FDA Law Blog from the law firm of Phelps and McNamara pointed out at the time, Athenex argued, among other things, that after Par received FDA approval for its product, it “leveraged its exclusivity to maximize sales,” and the “average wholesale price of intravenous vasopressin surged 3141%—from $4.27 to $148.40 per vial.”

Endo then challenged Athenex’ right to move forward with its products. Now, with an agreement from Athenex, Endo has again stayed the litigation after a Sept. 20 conversation with the FDA in which the agency said it will get everything sorted out by year’s end.