Auto-Injected Testosterone May Address Some TRT Shortcomings

CHICAGO—Testosterone replacement therapy (TRT) using an auto injector to self-administer testosterone subcutaneously once-weekly maintains testosterone levels in a clinically desirable and physiologically normal range in hypogonadal men, according to study findings presented presented at the 2018 annual meeting of the Large Urology Group Practice Association.

The findings are from the phase 3 STEADY trial, which enrolled 150 men with hypogonadism to evaluate the efficacy, safety, and pharmacokinetics of the drug-device combination (XYOSTED). The men had a mean age of 53.4 years and mean baseline total testosterone level of 230 ng/dL. Starting doses of 75 mg were administered once-weekly for 6 weeks. Dose adjustments when necessary to address lower or higher levels were made at week 7 using 100 mg or 50 mg strengths.

Of the 150 patients, 139 (92.7%) met the study’s primary end point—a testosterone level of 300 to 1100 ng/dL—at week 12, investigators reported in a poster presentation. The compliance rate was 98.5%, with 98 men still receiving treatment at week 52.

Jonathan S. Jaffe, MD, Vice President of Clinical Development for Antares Pharma Inc, in Ewing, New Jersey, which developed the product, called the development of the auto-injector, which delivers highly viscous testosterone enanthate in sesame oil through a 27-gauge needle in under 10 seconds, “a profound mechanical feat.” The product, which was approved by the FDA in September, is a once-weekly pre-filled, single-use, disposable device designed to avoid the problems associated with other TRT options, Dr Jaffe and colleagues noted. Topical treatments may result in testosterone exposure to other individuals, buccal and nasal treatments require twice- or thrice-daily dosing, and intramuscular formulations can result in supraphysiologic peaks and subsequent subphysiologic troughs in testosterone levels.

Over 52 weeks, trough levels, which reflect exposure, remained constant and testosterone levels during the entire 7-day post-dose interval, were therapeutic, Dr Jaffe said. The product could decrease the number of blood draws and dose adjustments typically required with other testosterone therapies.

Sixty-six patients (44%) experienced adverse events related to the product. These events were mostly reported as mild or moderate. Thirty patients (20%) discontinued the study because of treatment-emergent adverse events (TEAEs). The most frequently reported TEAEs leading to study discontinuation were increased PSA (13 patients) and elevated hematocrit (7 patients).

The majority of injections (1510 of 1519) were reported as painless.

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Reference

Jaffe JS. Safety, efficacy, metabolic parameters and patient satisfaction from the phase 3 STEADY trial of a novel, pre-filled subcutaneous testosterone enanthate auto-injector (XYOSTED) for testosterone replacement therapy. Presented at the 2018 annual meeting of the Large Urology Group Practice Association in Chicago, Nov. 1-3.