A New Oral Testosterone Undecanoate Formulation Restores Testosterone to Normal Concentrations in Hypogonadal Men
Ronald S. Swerdloff, Christina Wang, William B. White, Jed Kaminetsky, Marc Gittelman, James Longstreth, Robert E. Dudley, Theodore M. Danoff
Abstract
CONTEXT: A novel formulation of oral testosterone (T) undecanoate (TU) was evaluated in a phase 3 clinical trial. OBJECTIVE: Determine efficacy, short-term safety, and alignment of new oral TU formulation with current US approval standards for T replacement therapy. DESIGN: Randomized, active-controlled, open-label study. SETTING AND PATIENTS: Academic and private clinical practice sites; enrolled patients were clinically hypogonadal men 18 to 65 years old. METHODS: Patients were randomized 3:1 to oral TU, as prescribed (JATENZO®; n = 166) or a topical T product once daily (Axiron®; n = 56) for 3 to 4 months. Dose titration was based on average T levels (Cavg) calculated from serial pharmacokinetic (PK) samples. T was assayed by liquid chromatography-mass spectrometry/mass spectrometry. Patients had 2 dose adjustment opportunities prior to final PK visit. Safety was assessed by standard clinical measures, including ambulatory blood pressure (BP). RESULTS: 87% of patients in both groups achieved mean T Cavg in the eugonadal range. Sodium fluoride-ethylenediamine tetra-acetate plasma T Cavg (mean ± standard deviation) for the oral TU group was 403 ± 128 ng/dL (~14 ± 4 nmol/L); serum T equivalent, ~489 ± 155 ng/dL (17 ± 5 nmol/L); and topical T, 391 ± 140 ng/dL (~14 ± 5 nmol/L). Modeling/simulation of T PK data demonstrated that dose titration based on a single blood sample 4 to 6 h after oral TU dose yielded efficacy (93%) equivalent to Cavg-based titration (87%). Safety profiles were similar in both groups, but oral TU was associated with a mean increase in systolic BP of 3 to 5 mm Hg. CONCLUSION: A new oral TU formulation effectively restored T to mid-eugonadal levels in hypogonadal patients.