A Study to Evaluate the Safety and Tolerability of TOS-358 in Women With HR+ HER2- Breast Cancer (NCT05683418)
A Study to Evaluate the Safety and Tolerability of the Covalent Phosphoinositide-3-Kinase (PI3K)-Alpha Inhibitor, TOS-358, in Adult Subjects With Select Solid Tumors
🩺 Plain-English Summary (8th-Grade Level)
The goal of this clinical trial is to evaluate the safety and efficacy of TOS-358 in women with HR+ HER2- metastatic breast cancer whose tumors have a mutation in PIK3CA and who meet all other study enrollment criteria. The main questions it aims to answer are: 1. Phase 1a: what is the maximum tolerated dose and recommended dose for phase 2? 2. Phase 1a: how safe and tolerable is TOS-358 at different dose levels when taken orally once or twice per day? 3. Phase 1b: how safe and effective is TOS-358 when given with standard of care medicines for HR+HER2- metastatic breast cancer (fulvestrant and CDK4/6i)
Who can join: Review the eligibility criteria below.
Location: Northwestern Memorial Hospital — Chicago, Illinois
Age range: 18 Years
🧪 Interventions in This Study
📋 "Do I Qualify?" — 1-Minute Self Screener
Instant ChecklistFull eligibility criteria are available on the official NIH protocol. View the criteria ↗
📍 All Participating Trial Locations (18 Sites)
- Northwestern Memorial Hospital — Chicago, Illinois
- Beth Israel Deaconess Medical Center — Boston, Massachusetts
- Dana-Farber Cancer Institute — Boston, Massachusetts
- Comprehensive Cancer Centers of Nevada — Las Vegas, Nevada
- University of Pennsylvania — Philadelphia, Pennsylvania
- Sarah Cannon Cancer Center — Nashville, Tennessee
- Vanderbilt-Ingram Cancer Center — Nashville, Tennessee
- Texas Oncology - Flower Mound — Flower Mound, Texas
- Virginia Cancer Specialists — Fairfax, Virginia
- NEXT Oncology - Hospital Quironsalud Barcelona - PPDS — Barcelona,
- START Barcelona HM Nou Delfos — Barcelona,
- Instituto de Investigacion Oncologica Vall dHebron (VHIO) - EPON — Barcelona,
- Hospital Clinico San Carlos — Madrid,
- START MADRID Hospital Universitario Fundacion Jimenez Diaz - EDOS — Madrid,
- START MADRID Hospital Universitario HM Sanchinarro - CIOCC — Madrid,
- Clinica Universidad de Navarra — Pamplona,
- NEXT Oncology - Hospital Quironsalud Madrid - PPDS — Pozuelo de Alarcón,
- Hospital Clinico Universitario de Valencia — Valencia,
📞 Contact the Study Coordinator
Phone: (312) 695-9361
Email: essence.baymon@northwestern.edu
Coordinator details come directly from the registered NIH protocol. Confirm the study is still recruiting before traveling.
💰 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.
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💡 How to Participate
- Check the checklist above to see if you may qualify.
- Contact the study coordinator using the phone/email above.
- Ask about the visit schedule, what is covered at no cost, and any travel support.
- Confirm with your own doctor before making a decision.