Mallinckrodt has sued the FDA over its decision to revoke the equivalence rating on the company’s generic version of Janssen’s attention deficit hyperactivity disorder drug Concerta.

The agency did so without prior notice or an opportunity for comment, in a violation of Mallinckrodt’s due process rights, the Irish drugmaker said in a complaint filed in Maryland federal court. The drugmaker asked for a temporary restraining order that would reverse the equivalence rating change pending a final ruling on the FDA’s decision.

The FDA decision to change the rating from AB interchangeable to BX, meaning the generic cannot automatically be swapped for branded Concerta (methylphenidate HCl), centered on concerns that the generics from Mallinckrodt and fellow drugmaker Kudco aren’t released at the same rate as the brand.

The move effectively took the companies’ versions off the market, Mallinckrodt said.
The problem, according to the lawsuit, is that the FDA cannot remove a product without an opportunity for a hearing, even when there are concerns for public health. Nor has the FDA furnished sufficient evidence to demonstrate that Mallinckrodt’s version is not effective, the firm added. 

In its lawsuit, Mallinckrodt continues to maintain that its version of Concerta, launched December 2012, is safe and effective. The firm reiterates prior assertions that there have been just 68 confirmed adverse events over a lack of efficacy when patients switched from branded Concerta to its generic. That’s compared with more than 88 million doses of Mallinckrodt’s version that have been prescribed.

The FDA changed its equivalence findings for the therapies six days after it issued a new draft guidance on bioequivalence testing for Concerta generics. At the time of the status change, the agency noted that it had found efficacy issues in nearly 200 adverse event reports on Mallinckrodt’s version.

Mallinckrodt also expressed concerns that the removal of its version and Kudco’s could create shortages. The only other approved generic version of Concerta is one from Janssen, which the FDA said did not experience similar equivalence issues.

The FDA’s stated policy is to not comment on pending litigation. — Bryan Koenig

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.