A 52-Week Study of Dose-Adjusted Subcutaneous Testosterone Enanthate in Oil Self-Administered via Disposable Auto-injector

Abstract

PurposeThis open-label, single-arm, dose-blinded, 52-week, registration-phase study evaluated the efficacy and safety of subcutaneous testosterone enanthate auto-injector (SCTE-AI) administered weekly to men with hypogonadism. MethodsPatients (N=150) were initiated on 75 mg SCTE-AI self-administered weekly. Dose adjustments were made at week 7 to 50, 75, or 100 mg testosterone enanthate (TE) based on week 6 total testosterone (TT) trough concentration. If required, dose adjustments continued through the extended treatment phase. Pharmacokinetic (PK) and clinical laboratory parameters, treatment-emergent adverse events (TEAEs), and injection site reactions were captured. ResultsThe primary endpoint was met: 92.7% of patients achieved an average TT concentration of 300–1100 ng/dL (553.3 ± 127.29 ng/dL, mean ± SD) at week 12. A Cmax of <1500 ng/dL was achieved by 91.3% of patients, and no patients had levels >1800 ng/dL at week 12. Mean TT Ctrough was 487.2 ± 153.33 ng/dL at week 52. Most patients (>95%) reported no injection-related pain. The most frequently-reported TEAEs were increased hematocrit, hypertension, and increased prostate-specific antigen, which led to discontinuation in 30 men. There were no study drug-related serious AEs. DiscussionDose-adjusted SCTE-AI demonstrated a steady serum TT PK profile, with small peak and trough fluctuations. SCTE-AI was safe, well tolerated, and virtually painless, indicating that SCTE-AI offers a testosterone delivery system that is a convenient weekly option for treatment of testosterone deficiency.