Biomarker-driven treatment selection for metastatic breast cancer

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This prospective study evaluates the impact of biomarker-driven early therapeutic switching and delayed imaging in patients with HR+ HER2- metastatic or unresectable breast cancer. Patients will start with a CDK4/6 inhibitor and endocrine therapy, with blood samples taken to assess thymidine kinase activity (TKa) at baseline and on day 15 of treatment. If TKa suppression is not observed, patients will switch therapies; if suppression is noted, they will continue treatment and delay imaging scans. The study aims to determine if TKa levels can predict progression-free survival on the initial therapy.

Why it matters

Who can join: the full rules

Inclusion Criteria - Patients

* Diagnosis of metastatic or advanced unresectable invasive breast cancer with MD intent to treat as HR-positive and HER2-negative, with the following arm-specific requirements:

  * Arm 1: Patient must be planning to initiate standard of care first-line therapy with FDA-approved endocrine therapy plus CDK4/6 inhibitor for the stated diagnosis at the time of study enrollment. Note: Ribociclib is the preferred CDK4/6 inhibitor, but alternative CDK4/6 inhibitors are allowed. Note: Initiation of endocrine therapy prior to ultimate plan for addition of CDK4/6 inhibitor is permitted prior to enrollment.
  * Arm 2: patient must be planning to initiate standard of care second-line therapy with FDA-approved endocrine therapy plus CDK4/6 inhibitor for the stated diagnosis at the time of study enrollment. Triplet regimens are permitted as long as they contain CDK4/6 inhibitor and endocrine therapy. Note: Initiation of endocrine therapy prior to ultimate plan for addition of CDK4/6 inhibitor is permitted prior to enrollment.
  * Arm 3: patient must be planning to initiate first- or second-line therapy for the stated diagnosis at the time of study enrollment with therapy other than endocrine therapy plus CDK4/6 inhibitor.
* Any prior therapy for early stage breast cancer is allowed, including endocrine therapy and chemotherapy.
* Prior receipt of adjuvant CDK 4/6 inhibitor therapy is permitted with the following arm-specific requirements:

  * Arm 1: CDK4/6 inhibitor may have been given only in the neoadjuvant/adjuvant setting (not metastatic setting), and the last dose must have been \> 12 months prior to study enrollment.
  * Arms 2 and 3: No restrictions on prior CDK4/6 inhibitors.
* Measurable or non-measurable disease per RECIST v1.1.
* At least 18 years of age.
* ECOG PS ≤ 2
* Post-menopausal status, defined as one of the following:

  * Age ≥ 60 years
  * Age \< 60 with intact uterus and amenorrhea for 12 consecutive months or more
  * Status post bilateral oophorectomy, total hysterectomy
  * Pre- or peri-menopausal with suppressed ovarian function by use of GnRH agonist/antagonist or surgical bilateral oophorectomy
* Ability to understand and willingness to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).

Exclusion Criteria - Patients

* Receipt of any prior cytotoxic chemotherapy line for metastatic disease. There will be no limit to chemotherapy use in the neoadjuvant or adjuvant setting.
* Prior or concurrent malignancy (unless that malignancy's natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen).
* Arms 1 and 2: Concurrent participation in any investigational therapeutic trial for treatment of metastatic breast cancer.

Eligibility Criteria - Physicians

* Medical Oncologist at Siteman Cancer Center.
* Treating patients with metastatic or advanced unresectable breast cancer.
* Willing to complete Physician Surveys during participation.

Where it's running

• Washington University School of Medicine
  St Louis, Missouri, United States Recruiting

Study contacts

• Principal investigator: Katherine Clifton, M.D. — Washington University School of Medicine
• Study coordinator: Katherine Clifton, M.D.
• Email: k.clifton@wustl.edu
• Phone: 314-273-3712

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Other studies for the same condition or treatment. Recruiting studies are listed first.

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.