FDA Staff Concerned About Safety of Testosterone Injection

April 16, 2013

(Reuters) - Reviewers for the U.S. Food and Drug Administration said safety data on Endo Health Solutions Inc's twice-rejected testosterone injection Aveed were "concerning" and showed that the therapy was associated with severe and immediate post-injection adverse events.

Aveed, or testosterone undecanoate, is a long-acting formulation of testosterone in castor oil and benzyl benzoate, and is intended for intramuscular injection.

No deaths were reported from the post-injection reactions, but resuscitations and hospitalizations were required in some cases, the reviewers said in documents posted on the FDA's website on Tuesday.

"There are no known approaches to predict or prevent the occurrence of an Aveed-related severe post-injection reaction for any patient," the FDA reviewers said.

"It is unclear whether a 'slowly administered' intramuscular injection or a 30 minute post-injection wait time in the healthcare provider's office will entirely mitigate this risk."

Endo is seeking approval for Aveed as replacement therapy in men for conditions associated with a deficiency or absence of testosterone hormone.

The FDA had first denied approval to the therapy in 2008 citing safety concerns, and then again in 2009 as it continued to believe that the drug's risks outweighed its benefits.

However, the reviewers said on Tuesday that the drug met the regulatory requirement for efficacy for a testosterone replacement indication.

The reviewers said that while considering a risk management strategy for Aveed, the primary benefit of the drug would be to administer fewer injections in a patient population that has a variety of other treatment options available.

Endo's failure to accurately characterize the drug's use, the consistent high rate of adverse events, and its "unwillingness to acknowledge or effectively address possible increased rates is concerning," the FDA staff said.

The most commonly reported adverse events were acne, fatigue, cough, injection site pain, insomnia and sinusitis, among others.

The FDA's advisory panel will vote on the drug's safety profile and approval on Thursday.