Endo Pharmaceuticals announced that it received a complete response letter from the US Food and Drug Administration (FDA) regarding the New Drug Application (NDA) for its extended-duration testosterone undecanoate injection, Aveed, for men diagnosed with low testosterone. Low testosterone is also known as hypogonadism.

In the complete response letter, the US FDA has requested information from Endo to address the agency's concerns regarding very rare but serious adverse events, including post-injection anaphylactic reaction and pulmonary oil microembolism. The letter also specified that the proposed Risk Evaluation and Mitigation Strategy (REMS) is not sufficient.

Endo is currently evaluating the FDA's complete response letter.

Known as Nebido outside the United States, Aveed was licensed from Bayer Schering Pharma AG, Germany to Indevus Pharmaceuticals, a company Endo acquired earlier this year. Nebido, discovered and developed by Bayer Schering Pharma, has subsequently been approved in 86 countries worldwide and is available in more than 50 countries across Europe, Asia Pacific and Latin America.

Endo Pharmaceuticals is a specialty pharmaceutical company engaged in the research, development, sale and marketing of branded and generic prescription pharmaceuticals used to treat and manage pain, prostate cancer and the early onset of puberty in children, or central precocious puberty (CPP).