GTx Announces Positive Results from Enobosarm Phase 2 Proof-of-Concept Clinical Trial in Women with Stress Urinary Incontinence

Truckee, CA (UroToday.com) GTx, Inc. announced top-line clinical trial results demonstrating that a daily dose of enobosarm 3 mg (GTx-024) substantially improved  (SUI) in women, as well as related quality of life measurements. In this open-label clinical trial, all 17 patients completing 12 weeks of treatment saw a clinically significant reduction (50 percent or greater) in stress leaks per day, compared to baseline. Mean stress leaks decreased by 83 percent from baseline over 12 weeks, and the reductions in daily stress leaks following completion of treatment have been sustained as patients are being followed for up to 7 months post-treatment to assess the durability of treatment effect. No patient has relapsed to her baseline levels. These results were presented at the International Continence Society (ICS) Annual Meeting currently being held in Florence, Italy from September 12-15, 2017.

“Since stress incontinence occurs when muscles that control one’s ability to hold urine get weak or do not work, it stands to reason that increasing pelvic floor muscle mass should reduce involuntary or unintentional leakage of urine”

“All 17 patients completing treatment have shown a significant reduction in the number of leaks per day recorded at their baseline, and the improvements in symptoms were sustained well beyond ceasing enobosarm treatment at 12 weeks,” said Kenneth M. Peters, M.D., Chairman of Urology, Oakland University William Beaumont School of Medicine, and the principal investigator in the trial. “The results in this proof-of-concept study are promising, and we are excited to be participating in a larger, placebo-controlled Phase 2 study.”

The podium presentation entitled “Kegels In A Bottle”: Preliminary Results Of A Selective Androgen Receptor Modulator (GTx-024) For The Treatment Of SUI In Post-Menopausal Women, summarized clinical data from the first 17 patients completing 12 weeks of enobosarm treatment, including the duration of response for up to 7 months following completion of enobosarm treatment. In this trial, a total of 19 post-menopausal women were enrolled by three clinical sites to receive enobosarm treatment. In addition to the 17 patients who completed treatment, another will complete treatment in approximately 8 weeks and one patient previously withdrew consent shortly after her initial visit. Data highlights were as follows:

Each of the women treated with enobosarm showed a clinically significant reduction in incontinence episodes per day:

  • Mean stress leaks decreased by 83% percent from baseline over 12 weeks
  • Stress leaks decreased from a mean of 5.08 leaks/day at baseline, to 0.88 leaks/day at Week 12
  • All 17 patients achieved the primary endpoint of reductions in leaks per day, compared to baseline, of at least 50% at Week 12
Reductions in incontinence episodes were sustained well beyond the 12 week treatment period:

  • Patients are being followed for up to 7 months post-treatment to assess duration of the drug’s effect, and to date no patient, including 6 patients who have reached 7 months, has returned to her baseline levels of SUI episodes
Women reported improved quality of life measurements in each of the five instruments collected in the study, including the Patient Global Impression of Improvement (PGI-I) and Female Sexual Function Index (FSFI):

  • At Week 12, 16 of 17 patients showed improved PGI-I scores and median FSFI scores improved from a baseline score of 15.90 to 28.05 at Week 12
There were no serious adverse events reported and reported adverse events were minimal and included headaches, nausea, fatigue, hot flashes, insomnia, muscle weakness and acne. Mild transient elevations in liver enzymes were observed, as well as reductions in total cholesterol, LDL, HDL and triglycerides. The abstract is available on the International Continence Society’s website.

Based on the results from its enobosarm Phase 2 proof-of-concept study, the Company has initiated a randomized, placebo-controlled Phase 2 clinical trial to evaluate the change in frequency of daily stress urinary incontinence episodes following 12 weeks of treatment. The trial will evaluate the safety and efficacy of enobosarm (1 mg and 3 mg) compared with placebo in postmenopausal women with SUI. Enobosarm has previously been evaluated in clinical trials enrolling in excess of 1,700 patients, in which approximately 1,200 individuals received doses ranging from 0.1 mg to 100 mg, and has been observed to be generally safe and well tolerated.

“Since stress incontinence occurs when muscles that control one’s ability to hold urine get weak or do not work, it stands to reason that increasing pelvic floor muscle mass should reduce involuntary or unintentional leakage of urine,” said Dr. William J. Evans, Adjunct Professor in the geriatrics program at the Duke University Medical Center. “The muscles of the pelvic floor are enriched with androgen receptors and are responsive to the body’s hormonal status which is why we hypothesize that a selective androgen receptor modulator, like enobosarm, could have a beneficial effect on SUI.”
 
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