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Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of BTX-9341 in Advanced and/or Metastatic Breast Cancer
Trial Status: active
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.
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)
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
Additional locations may be listed on ClinicalTrials.gov for NCT06515470.
Locations matching your search criteria
United States
Minnesota
Rochester
Mayo Clinic in Rochester
Status: Active
Name Not Available
Texas
Houston
M D Anderson Cancer Center
Status: Active
Name Not Available
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
