Company receives approvable letter for hypogonadism treatment

Indevus Pharmaceuticals, Inc. has received an approvable letter from FDA for its long-acting depot preparation of testosterone undecanoate (Nebido), which is indicated for the treatment of male hypogonadism.

The letter, received in June 2008, is related to a new drug application submitted in August 2007. It indicated that the application may be approved if the company is able to adequately respond to certain clinical deficiencies related to the product.

FDA has expressed a concern about a relatively small number of patients in European post-marketing who experienced respiratory symptoms immediately following the intramuscular injection of testosterone undecanoate, 1,000-mg, 4-cc injection volume (vs. the 750-mg, 3-cc injection volume used in the United States). The company said it believes, and FDA concurs, that the reaction is likely the result of a small amount of the oily solution immediately entering the vascular system from the injection site.

In Indevus’ U.S. clinical trials of the 750-mg dosage, a single, mild case of oil-based cough was observed. In addition, FDA believes that four cases in the European post-marketing experience may have an anaphylactoid component.

FDA has requested the company provide detailed follow-up data from ongoing U.S. and European studies to determine the precise incidence of serious post-injection oil-based reactions and allergic reactions. In addition, Indevus has been asked to provide both a plan to minimize the risks associated with the clinical use of the drug and certain in vitro and skin-testing data to exclude an allergic component to the drug or some of its excipients.