🏛️ Verified NIH Record • Updated 2026-01-09

Ovarian Suppression Evaluating Subcutaneous Leuprolide Acetate in Breast Cancer (NCT04906395)

Phase 3,Single Arm,Open-Label Study Evaluating Ovarian Suppression Following 3 Month Leuprolide Acetate For Injectable Suspension (TOL2506) in Combination With Endocrine Therapy in Premenopausal Subjects With Hormone-Receptor-Positive (HR+),Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Breast Cancer

🔵 Active, Not Recruiting Phase3 💊 Investigational Drug / Biologic Sponsor: Tolmar Inc.

🩺 Plain-English Summary (8th-Grade Level)

This is a phase 3, single arm, open-label study evaluating the effectiveness of TOL2506 to suppress ovarian function in premenopausal women with HR+, HER2-negative breast cancer. The study will also aim to assess the safety of TOL2506 in men with HR+, HER2-negative breast cancer. The Screening Period will be conducted in two parts: 1) an abbreviated, initial screening where premenopausal status will be determined prior to neoadjuvant or adjuvant chemotherapy (if planned) and 2) the full screening assessment conducted after neoadjuvant or adjuvant chemotherapy (or for subjects who enter the study without having received chemotherapy). Following the Screening Period, eligible subjects will enter into the 48 week Treatment Period in 1 of 2 groups: those who will receive tamoxifen concurrently with TOL2506 or those who will initiate therapy with an AI (letrozole, anastrozole, or exemestane) beginning 6 weeks after the first administration of TOL2506, upon confirmation that estradiol (E2) levels of \< 20 pg/mL (testosterone levels \< 50 ng/dL in males) have been achieved. After Week 12, subjects will be allowed to switch from receiving an AI to receiving tamoxifen or from tamoxifen to AI at the discretion of the Investigator. However, a switch is not permitted 28 days prior to a dosing visit (eg, Week 24, 36, and 48 where a pre-dose blood sample for PK and PD analysis will be drawn). At the end of the Treatment Period, upon completion of the End of Study Visit (Visit 9, Week 48) subjects may be eligible to participate in a Safety Extension Study under a separate Protocol.

Who can join: Review the eligibility criteria below.

Location: Marin Cancer Care, Inc — Greenbrae, California

Age range: 18 Years to 49 Years

📋 "Do I Qualify?" — 1-Minute Self Screener

Instant Checklist

Full eligibility criteria are available on the official NIH protocol. View the criteria ↗

📍 All Participating Trial Locations (59 Sites)

Showing the first 25 of 59 sites.

  • Marin Cancer Care, Inc — Greenbrae, California
  • Cypress Hematology and Oncology — Parker, Colorado
  • Mount Sinai Hospital — Chicago, Illinois
  • Baptist Health Louisville — Louisville, Kentucky
  • Maryland Oncology Hematology, P.A. — Glenn Dale, Maryland
  • Nebraska Cancer Specialists — Omaha, Nebraska
  • Montefiore - Einstein Center for Cancer Care at Montefiore Medical Park — The Bronx, New York
  • Oncology Hematology Care Clinical Trials — Cincinnati, Ohio
  • Lankenau Medical Center — Wynnewood, Pennsylvania
  • Tennessee Oncology, PLLC — Chattanooga, Tennessee
  • Tennessee Oncology, PLLC — Nashville, Tennessee
  • Texas Oncology-Austin — Austin, Texas
  • Texas Oncology- Dallas Presbyterian Hospital — Dallas, Texas
  • Texas Oncology- San Antonio — New Braunfels, Texas
  • Texas Oncology- Northeast Texas — Tyler, Texas
  • Texas Oncology- Deke Slayton Cancer Center — Webster, Texas
  • Seattle Cancer Center Alliance — Seattle, Washington
  • Hospital Britanico de Buenos Aires — Buenos Aires, Buenos Aires F.D.
  • Instituto Oncologico de Cordoba (IONC) — Córdoba, Córdoba Province
  • Centro Privado de RMI Rio Cuarto — Río Cuarto, Córdoba Province
  • Instituto Medico de la Fundacion Estudios Clinicos — Rosario, Santa Fe Province
  • Hospital Provincial del Centenario — Rosario, Santa Fe Province
  • Hospital Aleman — Buenos Aires,
  • Fundacion CENIT — CABA,
  • Sanatorio Allende- Sede Nueva Cordoba — Córdoba,

💰 Cost, Insurance & Patient Rights

  • 100% Free Items: The investigational treatment and protocol-required procedures are supplied at zero cost by the sponsor.
  • Routine Patient Care: Under federal law (ACA § 2709) and many state statutes, routine care costs are covered during participation.
  • Voluntary Participation: You may withdraw at any time without affecting your standard medical care.

Explore by condition: All Breast Cancer clinical trials

💡 How to Participate

  1. Check the checklist above to see if you may qualify.
  2. Review the official NIH record below to find the coordinating site.
  3. Ask about the visit schedule, what is covered at no cost, and any travel support.
  4. Confirm with your own doctor before making a decision.
🏛️ View Official NIH Record ↗