Pharmacokinetics, pharmacodynamics and safety of a novel hydroalcoholic testosterone gel 2% (TG) were evaluated in phase II sequential dose escalation studies using 3 application sites (thigh, abdomen and shoulder/upper arm) and 2 application methods. Hypogonadal men (n = 40), 18-75 years, with serum testosterone <300 ng dl(-1) were included in both studies. Study 1 evaluated hand-applied multiple doses of TG 1.25, 2.50 and 3.75 ml (23, 46 and 70 mg of testosterone, respectively), once daily for 10 days to shoulder/upper arm. Study 2 evaluated applicator-applied (TG 1.25, 2.50 and 3.75 ml) versus hand-applied (TG 2.5 ml) doses, once daily for 7 days to shoulder/upper arm. Primary endpoint for both studies was responder rate (Cave testosterone levels between 298 and 1050 ng dl(-1) ). In Study 1 following multiple applications, >70% participants in each group were responders. Dose-dependent increase was observed in PK values for total testosterone, free testosterone and DHT. In Study 2, responder rate was dose proportional: 16.7%, 50.0% and 77.8% responders in TG 1.25, 2.50 and 3.75 ml groups respectively. The bioavailability was highest for the shoulder application. There was a significant improvement in almost all the domains of sexual functioning. Applicator-application was preferred over hand-application by majority of the participants. TG was found to be safe and well tolerated in hypogonadal men.
Keywords: Efficacy; hydroalcoholic testosterone gel 2%; male hypogonadism; pharmacokinetics; pump applicator.
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