A phase IV prospective evaluation of the safety and efficacy of extended release testosterone pellets for the treatment of male hypogonadism.

Introduction: Men with hypogonadism exhibit decreased serum testosterone levels and may experience a constellation of clinical symptoms, including decrease in muscle mass, loss of sexual desire, impotence, and infertility. While previous studies have shown that implantation of extended release testosterone pellets can provide therapeutic levels of testosterone over several months, additional data are needed to establish this approach as the standard of care for male hypogonadism.

Aim: To evaluate the safety and efficacy of testosterone pellets over 6 months as a treatment for male hypogonadism in a clinical practice setting.

Methods: A phase IV, single center, open-label study designed to assess the safety and efficacy of subcutaneous insertion of 8 to 12 testosterone 75 mg pellets (450 mg to 900 mg), during a single implantation procedure in hypogonadal men. Subjects who successfully completed the protocol were allowed to enroll in an extension study that included another implantation and 6 months of follow-up.

Main Outcome Measures: Safety was determined by investigator-reported adverse events, changes in vital signs, physical exam findings, and laboratory tests. Efficacy was based on serum laboratory tests, physical exams, implantation site evaluations, and vital signs. Secondary objectives were to assess patient preference for testosterone pellets and to maintain optimal total testosterone.

Results: Mean testosterone significantly increased and luteinizing hormone (LH) levels significantly decreased from pre-implantation values at weeks 1, 4, and 12, and had returned to pre-implantation levels by week 24. Prostate-specific antigen levels remained unchanged for the duration of the study. Improvements in several symptoms of hypogonadism were determined with multiple questionnaires. Implanted testosterone pellets were generally well tolerated.

Conclusion: Implanted testosterone pellets can normalize testosterone and LH levels and improve symptoms for at least 3 months and up to 6 months in men with hypogonadism, and should be considered as a therapeutic option for hypogonadal men.