In a blow to AbbVie’s efforts to head off generic competition on its AndroGel 1%, the FDA said Irish drugmaker Perrigo’s testosterone gel product is bioequivalent and interchangeable.

Perrigo’s product has the same active ingredient, dosage form, route of administration and strength as AndroGel 1% (testosterone gel), the FDA said July 23 in response to AbbVie’s citizen petition that had sought a finding of non-equivalence, meaning it could not be swapped for the brand. Instead, the FDA gave Perrigo’s version an AB rating as safe to substitute.

The FDA also rejected AbbVie’s request for a requirement of additional rulemaking on bioequivalence before the FDA considered any AndroGel competitor. In addition, the agency rejected its request for a labelling change that said other topical testosterone products are not interchangeable with AndroGel. The FDA noted that versions of the product proposed by Perrigo and Teva already would be required to include warnings requested by AbbVie that testosterone gels may have different doses or application instructions.

Perrigo had originally submitted the drug as an ANDA but the FDA deemed there was need for additional clinical testing, and the company resubmitted the product under an NDA to perform that testing. Perrigo’s version passed those trials and became a generic as soon as the FDA granted it an AB rating, according to the company’s vice president for global regulatory affairs, Richard Stec.
The finding represents an important precedent, Stec said, affirming that drugs filed under NDAs can win an AB equivalence rating.

AbbVie’s petition was not entirely unsuccessful. While it now faces generic competition from Perrigo, the FDA sided with AbbVie in a parallel argument that sought a BX rating of non-equivalence for Teva’s testosterone gel. The difference between the generics products, the FDA found, is that Teva’s version fell outside of the range of bioequivalence during testing.

The petition’s finding also negates a lawsuit brought by Perrigo against the FDA in March that had sought a therapeutic equivalence finding to AndroGel from the agency. Perrigo dropped that lawsuit the day after the FDA issued its response to the citizen petition.

AndroGel is applied topically for men with low testosterone. AbbVie’s most recent earnings report lists the drug as one of its key products, having generated $218 million in sales in the second quarter of this year.

Perrigo had held off on marketing its version of AndroGel pending the AB rating, Stec said. The product can now go to market, although Perrigo did not give a possible timeline.

AbbVie said it was reviewing the decision and considering its next steps. — 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.