Introduction. A new formulation of testosterone gel (1.62% testosterone gel) with increased viscosity and reduced volume of application has been shown to be safe and efficacious after 182 days of use in a phase 3, double-blind study in adult hypogonadal males.
Aim. The objective of this study was to evaluate the efficacy and safety of the 1.62% testosterone gel after daily application to the skin in a 182-day (6-month) open-label extension of the initial 182-day double-blind study.
Methods. One hundred and sixty-three subjects, aged 26 to 77 years, continued on active (Continuing Active subjects) 1.62% testosterone gel for the remainder of the study (364 days total). In 28 subjects who had previously received placebo (Formerly Placebo subjects), the dose was titrated to normal levels of serum total testosterone (300–1,000 ng/dL). Dose adjustments for both groups were allowed at specific visits to maintain serum testosterone within a normal range.
Main Outcome Measure. The main outcome measure was the percentage of subjects with serum total testosterone average concentrations (Cav) within the normal range at day 364.
Results. On day 364, 77.9% (95% confidence interval: 70.0, 84.6) of the Continuing Active subjects and 87.0% (66.4, 97.2) of the Formerly Placebo subjects had Cav values within the eugonadal range. The 1.62% testosterone gel was safe and well tolerated in this study.
Conclusion. Treatment with 1.62% testosterone gel for up to 1 year (182 days for the Formerly Placebo subjects, 364 days for the Continuing Active subjects) was safe and efficacious, resulting in >77% of treated subjects achieving normal serum testosterone levels at final visit. Kaufman JM, Miller MG, Fitzpatrick S, McWhirter C, and Brennan JJ. One-year efficacy and safety study of a 1.62% testosterone gel in hypogonadal men: Results of a 182-day open-label extension of a 6-month double-blind study. J Sex Med 12;9:1149–1161.