Treatment Monitoring of Patients Receiving CDK 4/6 Inhibitors for Hormone Receptor (HR) Positive, HER2 Negative Metastatic Breast Cancer (MBC) With or Without the Addition of DiviTum® Serum Thymidine Kinase 1 (TK1) Activity Testing

Not Applicable

Recruiting

• Conditions: Breast Cancer; Cancer of the Breast
• Interventions: Device: DiviTum® TKa assay; Other: Study Care Plans

• Registration Number: NCT04968964
• Lead Sponsor: Washington University School of Medicine

Brief Summary

Historically, serial testing of patients with metastatic breast cancer has included a combination of physical exam, symptom evaluation, laboratory testing, and imaging. Circulating tumor biomarkers are sometimes also incorporated. Frequent testing with numerous diagnostics at each time point is a significant burden to patients and to healthcare systems.

The DiviTum® TKa assay measures TK1 activity. Numerous studies have illustrated the prognostic nature of plasma or serum TK1 activity level in metastatic cancer. The investigators hypothesize that the incorporation of data from DiviTum® TKa measurement into the treatment monitoring schema will be associated with physician desire to change the near-term usage and/or timing of other routine restaging tests, including either standard tumor imaging or tumor marker testing. Given the relatively low rate of disease progression in this first-line population, it is expected that most of this change will be an intended reduction in scheduling of routine treatment surveillance testing with increase in intervals of subsequent tumor restaging imaging by at least 4 weeks. Secondarily, the consequences of rescheduling of routine surveillance testing may ultimately result in an absolute reduction in the number of some tests used during the time period examined.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-07-08
• Study First Submitted QC: 2021-07-08
• Study First Posted: 2021-07-20
• Study Start: 2022-03-07
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-02
• Last Update Posted: 2025-01-03
• Primary Completion: 2027-08-01
• Study Completion: 2029-09-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 55

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Cohort 2: Currently receiving first line therapy	DiviTum® TKa assay	* 1st line therapy with endocrine therapy + any FDA-approved CDK 4/6 inhibitor for ≤ 24 months with stable disease * Serum samples (analyzed using DiviTum® TKa) at Baseline, Week 2, Week 4, Week 6, Week 8, Week 12, Week 16, Week 20, Week 24 and every 12 weeks thereafter until disease progression or 36 months. Treating physician will evaluate the patient \& review any updated results of the institutional standard of care monitoring tests. Following receipt of DiviTum® TKa value, the treating physician will review the preceding locked Study Care Plan and record any changes
Cohort 1: Scheduled to receive first line therapy	DiviTum® TKa assay	* Scheduled to receive 1st line therapy with endocrine therapy + any FDA-approved CDK 4/6 inhibitor * Serum samples (analyzed using DiviTum® TKa) at Baseline, Week 2, Week 4, Week 6, Week 8, Week 12, Week 16, Week 20, Week 24 and every 12 weeks thereafter until disease progression or 36 months. Treating physician will evaluate the patient \& review any updated results of the institutional standard of care monitoring tests. Following receipt of DiviTum® TKa value, the treating physician will review the preceding locked Study Care Plan and record any changes
Medical Oncologists	Study Care Plans	-Will be completing the Study Care Forms at Baseline, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24 and every 12 weeks thereafter until disease progression or 36 months.

Primary Outcome Measures

Name	Time	Method
Any physician-reported intended change in imaging testing interval identified on the study care plan post receipt of DiviTUM® TKa value	Within the first 48-week period of study participation

Secondary Outcome Measures

Name	Time	Method
Concordance rate between progression status on the first on-study imaging and progression status based on DiviTum® TKa values	At 12 weeks and 24 weeks
Cohort 1 only: DiviTum® TKa level	At 2 weeks post CDK 4/6 inhibitor therapy initiation
Number of surveillance imaging tests intended to be used and actually used, in total and by modality	Over the entire study period (estimated to be 36 months)
Longitudinal changes in DiviTum® TKa value dynamics	Over the entire study period (estimated to be 36 months)	The TK trajectory of a patients will be plot against time for temporal pattern and the trajectories will be modeled via linear or non-linear mixed effects mode as appropriate. If linear mixed effects model, the longitudinal rate of change will be estimated with 95% CI to indicate growth rate of TK. If non-linear, the regression coefficients of time or time relevant terms will be estimated with 95% CI

Trial Locations

Locations (1)

Washington University School of Medicine; 🇺🇸 Saint Louis, Missouri, United States