GTx Announces Enrollment of First Patient in Phase 2 Clinical Trial of Enobosarm in ER+/AR+ Breast Cancer

GTx, Inc.

today announced the enrollment of the first patient into its Phase 2 clinical trial of enobosarm (GTx-024) to treat women with advanced, estrogen receptor positive (ER+), androgen receptor positive (AR+) breast cancer. Enobosarm, a selective androgen receptor modulator (SARM), is the Company's lead product candidate. "Additional endocrine directed therapies are needed for the treatment of estrogen receptor positive breast cancer as many women who respond to hormonally directed therapy will continue to demonstrate response with subsequent hormonal manipulation," said Robert J. Wills, Ph.D., Executive Chairman of GTx. "We believe that enobosarm may provide a new hormonal approach for the treatment of estrogen receptor positive breast cancer and may delay the need for chemotherapy in these women." The open-label, multi-center, multinational Phase 2 clinical trial (NCT02463032) will assess the efficacy and safety of orally administered enobosarm in up to 88 evaluable patients with metastatic or locally advanced, ER+/AR+ breast cancer. Patients will receive either enobosarm 9 mg or 18 mg given daily for up to 24 months. The initial stage of evaluation will be assessed among the first 18 evaluable patients for each dosing arm. If at least 3 of 18 patients achieve clinical benefit at week 24, then the trial will proceed to the second stage of enrollment for that dosing arm to assess clinical benefit in a total of 44 evaluable patients per arm. Clinical benefit is defined as a complete response, partial response, or stable disease, as measured by Response Evaluation Criteria in Solid Tumors (RECIST) at 24 weeks. The lead investigator for the trial is Dr. Beth Overmoyer from the Dana Farber Cancer Institute and the Harvard Medical School.