Measuring a biomarker for breast cancer treatment effectiveness

DiviTum®TKa: A Biomarker Assay for Efficacy in HR+ Metastatic Breast Cancer Patients

Observational Mayo Clinic · NCT06388122

This study is testing if measuring a specific biomarker can help doctors understand how well hormone treatments are working for people with advanced breast cancer.

Quick facts

Study typeObservational
Enrollment100 (estimated)
Ages18 Years and up
SexFemale
SponsorMayo Clinic Academic / other
Locations1 site (Jacksonville, Florida)
Trial IDNCT06388122 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate the clinical utility of measuring thymidine kinase activity (TKa) in patients with hormone-receptor-positive metastatic breast cancer who are undergoing treatment with approved endocrine therapies, either alone or in combination with CDK4/6 inhibitors. The study will involve collecting biospecimens from participants to assess the relationship between TKa levels and treatment efficacy. Eligible patients include those starting or currently receiving specific lines of therapy for their condition. The findings could provide insights into optimizing treatment strategies for this patient population.

Who should consider this trial

Good fit: Ideal candidates are pre- or post-menopausal women with hormone-receptor-positive metastatic breast cancer receiving or scheduled to receive specific therapies.

Not a fit: Patients with HER2-positive breast cancer or those not receiving the specified therapies may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help tailor breast cancer treatments based on biomarker levels, potentially improving patient outcomes.

How similar studies have performed: Other studies have explored biomarker assessments in breast cancer, indicating potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Pre- or post-menopausal HR+ metastatic breast cancer patients who are:

  * Group 1: scheduled to initiate 1st line combination therapy with an FDA-approved CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) and an FDA-approved endocrine therapy for pre- or post-menopausal HR+ metastatic breast cancer (mBC).
  * Group 2: scheduled to initiate second or later lines of therapy with an FDA-approved CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) with or without an FDA-approved endocrine therapy for pre- or post-menopausal HR+ mBC.
  * Group 3: currently receiving 1st line therapy with an FDA-approved CDK4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) and an FDA-approved endocrine therapy for pre- or post-menopausal HR+ mBC.
  * Group 4: scheduled to initiate, or are currently receiving, 1st or 2nd line therapy of an FDA approved endocrine therapy (single agent) for pre- or post-menopausal HR+ mBC.

NOTE: Patients that meet eligibility criteria for any of the above groups that are already enrolled in an ongoing clinical trial are eligible for co-enrollment to this observational study.

Exclusion Criteria:

* Treatment including investigational agent or therapies
* Early breast cancer diagnosis
* Male breast cancer
* Currently receiving treatment for other active malignancy at time of registration

  * EXCEPTIONS: Nonmelanoma skin cancer or carcinoma-in-situ (e.g. of cervix, prostate)
* Inability to give written informed consent

Where this trial is running

Jacksonville, Florida

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HER2-negative Breast CancerHormone-receptor-positive Breast CancerMetastatic Breast Cancer
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.