FDA Releases Draft Guidance for Lenalidomide Bioequivalence Testing

The US Food and Drug Administration (FDA) has released a new draft guidance regarding bioequivalence (BE) recommendations for lenalidomide capsules.

Lenalidomide capsules, marketed by Celgene Corporation under the trade name Revlimid, are an analogue of Thalidomide and used to treat multiple myeloma. The latter was notorious in the late 1950s and early '60s for causing horrific birth defects in countries where the drug was approved-which did not, as FDA is proud to note, include the US-and the former was approved in 2005 with heavy restrictions on its use.

Physicians, for example, may only prescribe the drug after registering with a special education program geared toward making sure they understand the drug's teratogenic risks. Female patients must be prescribed birth control for several weeks before taking the drug, and for weeks after stopping treatment as well. Male patients are meanwhile advised to use contraception-condoms-because of the potential for lenalidomide to affect sperm, though this is unconfirmed.

FDA came out with a draft guidance on BE studies used to support an abbreviated new drug application (ANDA) in June 2010 in which it recommended studies be undertaken at both the 15mg and 25mg dose strengths to show BE.

In its new draft guidance, however, FDA said it has determined that the 15mg dose testing "is unnecessary," and sponsors may waive the requirements for the 2.5mg, 5mg, 10mg and 10mg strengths based on testing at the 25mg strength.

FDA said those waivers will be granted if sponsors can show three things: "Acceptable fasting and fed bioequivalence studies on the 25 mg strength, (2) proportional similarity of the formulations across all strengths, and (3) acceptable in vitro dissolution testing of all strengths."

The full draft guidance is available here.