(204) INITIATING HIGH-DOSE ORAL TESTOSTERONE UNDECANOATE THERAPY IN HYPOGONADAL MEN: SAFETY, EFFICACY, AND PATIENT SATISFACTION

Abstract Introduction Hypogonadism in men is commonly treated with testosterone replacement therapy. Kyzatrex (Marius Pharmaceuticals), a novel oral testosterone undecanoate (TU) formulation, is conventionally initiated at a dose of 200 mg BID. However, many patients attain greater symptomatic benefit at higher doses. In our practice we often initiate therapy at a starting dose of 400 mg BID. This retrospective chart review examines the outcomes of initiating therapy at 400 mg BID. Objective Retrospectively report the safety, efficacy, patient satisfaction, and adherence of starting hypogonadal men on oral TU at the maximum available dose of 400 mg BID. Methods This retrospective, single-center chart review included hypogonadal men treated with oral TU at 400 mg BID from August 2023 to April 2024. Medical records were reviewed for baseline and follow-up levels of serum total testosterone (TT), sex hormone binding globin (SHBG), calculated free testosterone (fT), Estradiol, Hematocrit (Hct), follicle stimulating hormone (FSH), and luteinizing hormone (LH). Satisfaction was subjectively recorded in the medical record and adherence was measured by prescription refill records. Results A total of 27 patients met the inclusion criteria and had complete data. At a mean follow up time of 6 months, patients demonstrated a significant increase in TT (263 to 798 ng/dL), drop in SHBG (32.4 to 17.83 nmol/L), and increase in calculated fT (7.24 to 26.74 ng/dL). FSH and LH, while lower, were maintained at non-zero levels (FSH from 5.7 to 2.9 mIU/mL and LH from 3.3 to 1.9 mIU/mL). Estradiol modestly increased (20.5 to 24.7 pg/mL) while hematocrit did not significantly increase (44.9% to 47.4%). No patients reported testicular atrophy or were initiated on aromatase inhibitors. One patient had a hematocrit rise above 52% (53.2%) and was reduced to 300 mg BID. Patient reported side effects were rare with 2 patients (7.4%) reporting transient GI upset. Subjective patient satisfaction was high, with 26/27 (96%) of patients reporting improvement in symptoms and continuing on therapy. One patient opted to convert to testosterone cypionate injections instead. Conclusions Initiating oral TU therapy with Kyzatrex at 400 mg BID is safe and effective in achieving therapeutic serum testosterone levels. The high dose was well-tolerated and resulted in substantial symptom improvement, high patient satisfaction, and adherence. These findings support considering a higher starting dose for hypogonadal men considering oral TU therapy. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Senior author serves as consultant for Marius Pharmaceuticals, Boston Scientific, Endo Pharmaceuticals.