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Repros Therapeutics Inc. (RPRX - Snapshot Report) recently provided top-line results from the ZA-301 study on its late-stage candidate, Androxal, which is being evaluated for the treatment of secondary hypogonadism. The ZA-301 study met both the primary endpoints.

The phase III program on Androxal includes two identical pivotal phase III studies, ZA-301 and ZA-302. The ZA-301 study had 151 patients randomized in a 3:1 ratio; 113 on Androxal and 38 on placebo.

The results showed that 79% of the patients had a 24-hour average total testosterone in a normal range at the end of the 12-week study period. Completer – a separate analysis – showed 83% of men were within the normal testosterone range.

The second primary endpoint was related to the drug’s impact on sperm concentration, which met the FDA threshold criteria as Androxal exhibited non-inferiority to placebo at a margin of 20%. Repros reported that Androxal was generally well-tolerated with no adverse events leading to discontinuation in the Androxal arm.

Earlier this year, the company had announced that it has completed the enrollment process in the one-year study, DEXA (ZA-303), evaluating the effects of Androxal on bone mineral density. The company completed enrollment three months before the scheduled date.

We are encouraged by the positive data from the ZA-301 study. Although the testosterone replacement therapy (TRT) market is pretty crowded, it nevertheless represents huge potential.

According to information provided by Repros, around 13 million men in the US are estimated to suffer from low levels of testosterone. Moreover, the company said that about 70% of men that have low testosterone suffer from secondary hypogonadism.

Androxal, which is being developed as an oral therapy for the treatment of the cause of secondary hypogonadism, could provide patients with a differentiated treatment option once launched. Currently, the most used treatment for secondary hypogonadism is testosterone replacement therapy. The market has products like Axiron (testosterone solution), Testim (testosterone gel), AndroGel (testosterone gel) and Androderm (patch therapy).

Repros currently carries a Zacks Rank #4 (Sell). Currently, companies like Transcept Pharmaceuticals, Inc. , Cleveland BioLabs, Inc. and Biogen Idec Inc. (BIIB - Analyst Report) look more attractive with a Zacks Rank #1 (Strong Buy).

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