As part of Dr. Orlando’s analyses he also looked at the impact of Androxal and Androgel on luteinizing hormone (LH) and follicle stimulating hormone (FSH) in the men with baseline morning testosterone ≤ 250 ng/dl. Androxal significantly increased LH levels in a dose dependent manner. LH stimulates the testes to produce testosterone. Androxal also significantly increased FSH in a dose dependent manner. FSH stimulates the testes to produce sperm. He further determined that there was a statistically significant correlation between changes in LH and changes in morning testosterone level (correlation = 0.6137, p value <0.0001). This analysis underscores the mode of action of Androxal which restores pituitary responsiveness to low circulating levels of testosterone, in turn stimulating the testes to produce normal levels of testosterone in a normal rhythmic pattern.
Conversely, Androgel significantly reduced pituitary secretions of both LH and FSH which further suppressed testicular function, and causes variability in testosterone levels not corresponding to the normal rhythmic pattern observed in healthy males.
One of the safety assessments proposed by the FDA that will be made in the planned Phase IIb study is to assess the impact of Androxal compared to placebo and Testim (an approved topical testosterone preparation) upon the reproductive status of men receiving three months of treatment with the study drugs. Dr. Orlando also observed that over 62% of men on Androgel in the analysis of the 003 study exhibited FSH levels below the lower limit of normal (1.4 mIU/ml) after three months of Androgel treatment, and noted that over 43% of those men had FSH levels below the lower limit of detection 0.3 mIU/ml. In a previous proof of principle study conducted by Repros it was found that roughly 80% of men with FSH levels less than 2.0 exhibited sperm parameters that would be considered sub fertile. After three months of treatment all men on the 25 mg dose of Androxal had FSH levels above 1.4 mIU/ml (minimum observed 2.9).