Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of BTX-9341 in Advanced and/or Metastatic Breast Cancer
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: BTX-9341, Fulvestrant, BTX-9341.
- Who it may be relevant to
- Registry conditions: Breast Cancer. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
A First-in-Human, Open-Label, Dose Escalation and Expansion Trial of BTX-9341 in Participants With Advanced and/or Metastatic Breast Cancer
Overview
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.
Detailed description
This first-in-human (FIH), Phase 1 study of BTX-9341 is multicenter, nonrandomized, and open-label to evaluate the safety, tolerability, pharmacokinetics (PK), and preliminary efficacy of BTX-9341 in participants with advanced and/or metastatic HR+/HER2 breast cancer. The study will include a dose escalation part (Part A) followed by a dose expansion part (Part B). During Part A, BTX-9341 will initially be dose escalated alone and then in combination with fulvestrant. A single combination therapy cohort of BTX-9341 + fulvestrant will be further explored in Part B. BTX-9341 will be administered orally in 28-day treatment cycles.
Interventions
- Drug BTX-9341
Daily oral dose in 28-day cycles until maximum tolerated dose (MTD) or maximum evaluable dose (MED) determined - Drug Fulvestrant
500 mg intramuscular injections on Day 15 and then every 28 days - Drug BTX-9341
Daily oral dose in 28-day cycles using dose determined in Part A
Primary outcome measures
- Safety and Tolerability of BTX-9341 [Time frame: Up to 28 days after last dose of BTX-9341]
- Part A: Number of Participants With Dose Limiting Toxicities (DLTs) [Time frame: 28 days]
- Part A: Determine MTD/MED of BTX-9341 in monotherapy [Time frame: Approximately 1 year from study start]
- Part A: Determine MTD/MED of BTX-9341 in combination therapy [Time frame: Approximately 18 months from study start]
- Part B Combination Therapy: Objective Response (OR) rate [Time frame: Approximately 18 months from start of Part B]
Eligibility criteria
Inclusion criteria
- Metastatic and/or locally advanced HR+/HER2- breast cancer (dose escalation: measurable disease and/or at least 1 lytic or mixed \[lytic + sclerotic\] bone lesion that can be assessed by CT or MRI or non-measurable disease \[including bone lesions\]; dose expansion: measurable disease)
- Dose escalation: (a) received not more than 1 chemotherapy in the metastatic/advanced setting; (b) no limit to the lines of endocrine therapy (monotherapy or combination therapy) in the metastatic setting; (c) received CDK4/6 inhibitor therapy
- Dose expansion: (a) received not more than 1 chemotherapy in metastatic/advanced setting; (b) received not more than 2 lines of endocrine therapy (monotherapy or combination therapy) and must have been on prior endocrine therapy for at least 6 months before progression; (c) 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
- Acceptable hematologic function
- ANC ≥ 1500 per mL. Note: Use of growth-factors to maintain the ANC criterion is prohibited.
- Platelet count ≥ 100,000 per mL. Note: Use of transfusions or thrombopoietic agents to achieve the baseline platelet count criterion is prohibited.
- Hemoglobin ≥ 9.0 g/dL. Note: Packed red blood cell transfusion is allowed up to 14 days prior to trial entry.
- Acceptable liver function
- Bilirubin ≤ 2.0 × institutional upper limit of normal (ULN) (or < 3.0 × institutional ULN if Gilbert's disease is present)
- Alanine transaminase (ALT)/aspartate aminotransferase (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)
- Able and willing to sign informed consent
- Meets all study requirements in the opinion of the Investigator
Exclusion criteria
- RB1 (retinoblastoma) gene mutation
- Symptomatic visceral disease
- Clinical evidence or history of central nervous system metastasis
- Abnormalities in coagulation, such as bleeding diathesis, or treatment with anticoagulants precluding injections of fulvestrant or luteinizing hormone-releasing hormone (LHRH) agonist
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Non-randomized
- Model
- Sequential
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
United States · 6 centers
- Biotheryx Investigative Site — Rochester
- Biotheryx Investigative Site — Omaha
- Biotheryx Investigative Site — Houston
- Biotheryx Investigative Site — San Antonio
- Biotheryx Investigative Site — West Valley City
- Biotheryx Investigative Site — Fairfax
Identifiers
NCT: NCT06515470 · BTX-9341-101