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

Recruiting

• Conditions: Metastatic Breast Cancer; HER2-negative Breast Cancer; Hormone-receptor-positive Breast Cancer
• Interventions: Procedure: Biospecimen Collection

• Registration Number: NCT06388122
• Lead Sponsor: Mayo Clinic

Brief Summary

The purpose of this study is to explore the clinical utility of routinely measuring thymidine kinase activity (TKa) in HR+ metastatic breast cancer patients receiving treatment with any approved endocrine therapy either alone or in combination with any approved CDK4/6 inhibitor.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2024-04-24
• Study First Submitted QC: 2024-04-26
• Study First Posted: 2024-04-29
• Study Start: 2024-04-30
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-15
• Last Update Posted: 2025-05-19
• Primary Completion: 2031-06-15
• Study Completion: 2031-06-15

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 100

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Group 1 (initiating 1st line CDK4/6 & endocrine therapy)	Biospecimen Collection	Blood will be drawn every 14 days starting from the first treatment cycle until the start of cycle 3; starting at cycle 3 blood will be drawn the first day of every cycle thereafter until progression. Optional blood draws will be taken with standard of care labs when starting next therapy.
Group 3 (currently receiving 1st line CDK4/6 and endocrine therapy)	Biospecimen Collection	Blood will be drawn on day 15 of the next cycle after enrollment and the first day of every cycle thereafter until progression. Optional blood draws will be taken with standard of care labs when starting next therapy.
Group 2 (initiating 2nd or later line of CDK4/6 with or without endocrine therapy)	Biospecimen Collection	Blood will be drawn every 14 days starting from the first treatment cycle until the start of cycle 3; starting at cycle 3 blood will be drawn the first day of every cycle thereafter until progression. Optional blood draws will be taken with standard of care labs when starting next therapy.
Group 4 (initiating or currently receiving 1st or 2nd line endocrine therapy)	Biospecimen Collection	Blood will be drawn at baseline or the first day of the treatment cycle and the first day of every cycle thereafter until progression. Optional blood draws will be taken with standard of care labs when starting next therapy.

Primary Outcome Measures

Name	Time	Method
DiviTum®TKa assay as an early predictor of primary treatment resistance	Every cycle (approximately 28 days) until disease progression up to 6 months	Blood samples collected from participants will be assessed using DiviTum®TKa assay for thymidine kinase activity (TKa) levels above Limit of Detection (LOD) as a predictor of primary treatment resistance. Primary treatment resistance will be defined as disease progression in less than 6 months.

Trial Locations

Locations (1)

Mayo Clinic in Florida; 🇺🇸 Jacksonville, Florida, United States