(Reuters) - Reviewers for the U.S. Food and Drug Administration said safety data on Endo Health Solutions Inc's twice-rejected testosterone injection Aveed was "concerning" and showed that the therapy was associated with severe and immediate post-injection adverse events.
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. (http://link.reuters.com/dem47t)
"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 a replacement therapy in adult males for conditions associated with a deficiency or absence of testosterone hormone.
The FDA 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 FDA's advisory panel will vote on the drug's safety profile and approval on Thursday.
"We expect a conservative advisory panel on April 18 due to the poor risk/benefit profile of Aveed and are not assigning any additional value to this product in our model," Cantor Fitzgerald analyst Irina Rivkind said.
The most commonly reported adverse events were acne, fatigue, cough, injection site pain, insomnia and sinusitis, among others.
Aveed, or testosterone undecanoate, is a long-acting formulation of testosterone in castor oil and benzyl benzoate, and is intended for intramuscular injection.
"We think that Aveed, if unexpectedly approved, could conservatively attain revenues in the $300 million range and add approximately $3 to Endo valuation," Rivkind added.
She has a "hold" rating and a $34 price target on Endo shares.
Endo shares were up 1 percent at $34.64 on the Nasdaq in late-morning trading.
(Reporting by Esha Dey in Bangalore; Editing by Roshni Menon, Maju Samuel)