OncoMatch/Clinical Trials/NCT06515470
Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of BTX-9341 in Advanced and/or Metastatic Breast Cancer
Is NCT06515470 recruiting? Yes, currently enrolling (Jun 2026). This Phase 1 trial studies multiple treatments including BTX-9341 and Fulvestrant for breast cancer.
Treatment: BTX-9341 · Fulvestrant · BTX-9341 — The purpose of this study is to test BTX-9341 alone or in combination with fulvestrant (a currently marketed medication for breast cancer) in participants with advanced and/or metastatic hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer. The study includes a dose escalation part (Part A) where small groups of participants will receive increasing doses of BTX-9341 or BTX-9341 + fulvestrant followed by a dose expansion part (Part B) where participants will receive the dose of BTX-9341 selected in Part A + fulvestrant.
Check if I qualifyExtracted eligibility criteria
Treatments studied
Endocrine / hormonal
Other
Cancer type
Breast Carcinoma
Biomarker criteria
Excluded: RB1 mutation
Prior therapy
Must have received: CDK4/6 inhibitor — dose escalation: any; dose expansion: at most 2 lines (1 adjuvant, 1 metastatic), at least 6 months duration
received CDK4/6 inhibitor therapy (dose escalation); received at most 2 lines of CDK4/6 inhibitor therapy (1 in the adjuvant setting and 1 in the metastatic setting) and must have been on prior CDK4/6 inhibitor therapy for at least 6 months (dose expansion)
Lab requirements
Blood counts
ANC ≥ 1500 per mL (no growth factors allowed); Platelet count ≥ 100,000 per mL (no transfusions or thrombopoietic agents allowed); Hemoglobin ≥ 9.0 g/dL (packed red blood cell transfusion allowed up to 14 days prior to trial entry)
Liver function
Bilirubin ≤ 2.0 × institutional ULN (or < 3.0 × institutional ULN if Gilbert's disease is present); ALT/AST ≤ 3.0 × institutional ULN (≤ 5.0 × institutional ULN if liver metastases present); Alkaline phosphatase ≤ 2.5 × institutional ULN (≤ 5.0 × institutional ULN if bone or liver metastases present)
Acceptable hematologic function: ANC ≥ 1500 per mL. Platelet count ≥ 100,000 per mL. Hemoglobin ≥ 9.0 g/dL. Acceptable liver function: Bilirubin ≤ 2.0 × institutional ULN (or < 3.0 × institutional ULN if Gilbert's disease is present); ALT/AST ≤ 3.0 × institutional ULN (≤ 5.0 × institutional ULN if liver metastases present); Alkaline phosphatase ≤ 2.5 × institutional ULN (≤ 5.0 × institutional ULN if bone or liver metastases present)
Structured fields extracted by AI. May contain errors — verify against the official protocol.
US trial sites
- Biotheryx Investigative Site · Rochester, Minnesota
- Biotheryx Investigative Site · Omaha, Nebraska
- Biotheryx Investigative Site · Houston, Texas
- Biotheryx Investigative Site · San Antonio, Texas
- Biotheryx Investigative Site · West Valley City, Utah
Showing up to 5 US sites.
See all sites on ClinicalTrials.gov →Frequently asked questions
Is NCT06515470 currently recruiting?
Yes, this trial is currently recruiting patients.
Is prior treatment required for enrollment?
Yes. Patients must have previously received CDK4/6 inhibitor.
Are patients with RB1 alterations eligible?
No. RB1 mutation is an exclusion criterion.
Could you qualify for this trial?
Enter your biomarker results to see how this trial's eligibility criteria match your specific cancer profile.
Check if I qualifyRelated pages