Clinical Evaluation of Subcutaneous Testosterone Implants in Men With Symptomatic Hypogonadism

Introduction:

Male hypogonadism is a clinical syndrome associated with significant consequences for health and quality of life. In Brazil, approved testosterone replacement therapy options are limited to injectable formulations and transdermal gels, which are often associated with suboptimal adherence. Subcutaneous testosterone implants, already used in the United States and recommended by international guidelines, represent a promising alternative but are not yet available in Brazil.

Objective:

To evaluate the efficacy, safety, pharmacokinetics, and quality-of-life impact of 200 mg testosterone implants manufactured in Brazil for the treatment of men with symptomatic hypogonadism.

Methods:

This is a prospective interventional study conducted at the Division of Urology of the Hospital das Clínicas, University of São Paulo School of Medicine (FMUSP). Thirty cisgender hypogonadal men meeting strict inclusion and exclusion criteria will be enrolled. Participants will receive subcutaneous testosterone implants totaling 800 mg and will be followed for six months. Serial blood sampling will be performed to assess hormonal levels (total and free testosterone, LH, FSH, and PSA) and metabolic parameters (lipid profile, body mass index, and waist circumference). Validated questionnaires, including the IIEF-15, ADAM, and WHOQOL-BREF, will be used to evaluate sexual function, hypogonadal symptoms, quality of life, and patient satisfaction.

Outcomes:

The primary outcome is the ability of the implants to achieve and maintain therapeutic serum testosterone levels (450-800 ng/dL). Secondary outcomes include pharmacokinetic profile (Cmax, half-life, and mean duration), metabolic effects, changes in quality of life, and treatment adherence.

Clinical Significance:

This study advances the understanding of a testosterone replacement modality that may offer greater convenience for selected patients and for which data on nationally manufactured products are currently lacking. Over a six-month period, the study will investigate laboratory behavior, clinical impact, and patient satisfaction.

Relevance and Impact:

This is the first study of its kind conducted in Brazil, combining methodological rigor with a robust design to evaluate the safety and efficacy of domestically manufactured testosterone implants. The methodology incorporates detailed ethical and scientific criteria, ensuring high-quality data. The results may support regulatory and clinical decision-making, benefiting patients and potentially contributing to the Brazilian Unified Health System (SUS).