Anatomic Stage IV Breast Cancer AJCC v8NCT06572800
Tka Assay for CDK4/6i
A study testing DiviTum-TKa in people with Anatomic Stage IV Breast Cancer AJCC v8 and Metastatic HER2-Negative Breast Carcinoma, run by Yale University at 18 sites in United States.
Trial summary
This clinical trial assesses whether using a test developed by DiviTum can identify optimal levels of CDK 4/6 inhibitor medications in the blood and whether assessing medical compliance and drug-drug interactions can optimize (improve) these levels in patients with estrogen receptor (ER) or progesterone receptor (PR)… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Anatomic Stage IV Breast Cancer AJCC v8, Metastatic HER2-Negative Breast Carcinoma
- What is being tested?
- DiviTum-TKa
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 34 participants
- Where
- 18 sitesUnited States
- Study dates
- 5 Sep 2023to 16 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participants must have histologically confirmed metastatic ER-positive (> 10%), PR-positive or PR-negative, and HER2-negative (0 by immunohistochemistry [IHC] or if +1 or +2 by IHC, not amplified by fluorescence in situ hybridization [FISH]) breast cancer; ER positivity, PR positivity, and HER2 negativity as per the 2018 joint American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.
- Participants must be starting CDK4/6 inhibitor and endocrine therapy as part of first-line therapy per standard of care and be previously CDK4/6 inhibitor-naïve.
- Participants must be enrolled prior to starting CDK4/6 inhibitor therapy.
- Participants must be ≥ 18 years of age.
- Participants must have an Eastern Cooperative Oncology Group (ECOG) Performance Status < 3.
- Willing and able to provide written informed consent for the trial.
Who cannot join
- Participants without evidence of metastatic disease prior to registration.
- Participants with prior use of CDK4/6 inhibitor therapy.
- Participants who are unable to provide informed consent for the trial.
Trial locations and contacts
18 sites in 1 country.
18 sites in 1 country
United States18 sites
Smilow Cancer Hospital-Derby Care Center
Derby, Connecticut, 06418
Smilow Cancer Hospital Care Center-Fairfield
Fairfield, Connecticut, 06824
Smilow Cancer Hospital Care Center at Glastonbury
Glastonbury, Connecticut, 06033
Smilow Cancer Hospital Care Center at Greenwich
Greenwich, Connecticut, 06830
Smilow Cancer Hospital Care Center - Guilford
Guilford, Connecticut, 06437
Smilow Cancer Hospital-Hamden Care Center
Hamden, Connecticut, 06518
Smilow Cancer Hospital Care Center at Saint Francis
Hartford, Connecticut, 06105
Smilow Cancer Center/Yale-New Haven Hospital
New Haven, Connecticut, 06510
Yale-New Haven Hospital Saint Raphael Campus
New Haven, Connecticut, 06511
Yale University
New Haven, Connecticut, 06520
Yale-New Haven Hospital North Haven Medical Center
North Haven, Connecticut, 06473
Smilow Cancer Hospital-Orange Care Center
Orange, Connecticut, 06477
Smilow Cancer Hospital Care Center at Long Ridge
Stamford, Connecticut, 06902
Smilow Cancer Hospital-Torrington Care Center
Torrington, Connecticut, 06790
Smilow Cancer Hospital Care Center-Trumbull
Trumbull, Connecticut, 06611
Smilow Cancer Hospital-Waterbury Care Center
Waterbury, Connecticut, 06708
Smilow Cancer Hospital Care Center - Waterford
Waterford, Connecticut, 06385
Smilow Cancer Hospital Care Center - Westerly
Westerly, Rhode Island, 02891
About this study
Official title: Use of DiviTum-TKa as a Biomarker Assay for CDK4/6 Inhibitor Medication Compliance and Drug-Drug Interaction Assessment in ER/PR Positive Metastatic Breast Cancer
This clinical trial assesses whether using a test developed by DiviTum can identify optimal levels of CDK 4/6 inhibitor medications in the blood and whether assessing medical compliance and drug-drug interactions can optimize (improve) these levels in patients with estrogen receptor (ER) or progesterone receptor (PR) positive, and human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic) and are receiving CDK 4/6 inhibitors. CDK4/6 inhibitors in combination with endocrine therapy (ET) is first line treatment for metastatic hormone positive (ER/PR positive) breast cancer (mBC). Thymidine kinase is a biomarker (biological molecule found in blood, other body fluids, or tissues that is a sign of a condition or disease) that reflects cell proliferation (an increase in the number of cells as a result of cell growth and cell division). DiviTum-thymidine kinase activity (TKa) is a Food and Drug Administration approved assay which showed that a TKa is associated with the decreased likelihood of disease progression within 30 days or 60 days post testing. Using the DiviTum-TKa may improve medication compliance and remove potential drug-drug interactions in patients with ER/PR positive HER2-negative MBC.
Read the detailed description
PRIMARY OBJECTIVE:
- To estimate the rate of improvement in CDK4/6 inhibitor response (i.e. moving from profile 3 to profiles 1 or 2) in cycles 2 and 3 after counseling for medication compliance and adjustment of potential deleterious drug-drug interactions.
SECONDARY OBJECTIVES:
- Estimate the rate of sub-optimal CDK 4/6 inhibitor response (profile 3) in patients with metastatic hormone positive breast cancer in cycle 1 of CDK4/6 inhibitor and endocrine therapy in the first line setting.
II. Compare clinical benefit rate (CBR) in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK4/6 inhibitor response after both cycles 1 and cycle 3.
III. Compare progression free survival (PFS) rates at 6 months (mo), 12 mo, 18 mo in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK 4/6 inhibitor response after both cycles 1 and cycle 3.
IV. Assess CDK4/6 inhibitor response via TKa levels upon CDK4/6 inhibitor dose reductions or changes in CDK4/6 inhibitor regimens.
- Compare CDK4/6 inhibitor response profiles across the three CDK 4/6 inhibitors among different patients and within the same patients if CDK4/6 inhibitor is changed throughout treatment course.
VI. Correlate TKa levels with tumor marker levels. VII. Assess plasma concentrations of CDK4/6 inhibitor drugs in patients with suboptimal TKa levels.
OUTLINE:
Patients undergo collection of blood samples per standard of care (SOC) on days 1, 15, and 28 of cycle 1, days 15 and 28 of cycle 2, days 15 and 28 of cycle 3, and day 28 of subsequent cycles for up to 12 cycles for analysis by DiviTum-TKa in the absence of disease progression or unacceptable toxicity.
After completion of study intervention, patients are followed up for 2 years.
- Being tested
- DiviTum-TKa
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DiviTum-TKaDevice
Analyze blood samples by DiviTum-TKa
| Study group | Role | What they receive |
|---|---|---|
| Health services research (DiviTum-TKa) | Experimental | Patients undergo collection of blood samples per SOC on days 1, 15, and 28 of cycle 1, days 15 and 28 of cycle 2, days 15 and 28 of cycle 3, and day 28 of subsequent cycles for up to 12 cycles for analysis by DiviTum-TKa in the absence of disease progression or unacceptable toxicity. Receives: Device: DiviTum-TKa |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of patients with thymidine kinase activity (TKa) values that switch from profile 3 to profile 1 or 2 after medication compliance and drug-drug interaction assessment
Will be estimated using the two-sided 95% exact confidence interval (CI) using Clopper-Pearson method.
Measured: Immediately following counseling for medication compliance and adjustment of potential deleterious drug-drug interactions
Rate of improvement in CDK4/6 inhibitor response (i.e. moving from profile 3 to profiles 1 or 2)
Will be estimated using the two-sided 95% exact CI using Clopper-Pearson method.
Measured: At day 28 of cycles 2 and 3 immediately following counselling for medication compliance and removing potential deleterious drug-drug interactions
Secondary outcomes (4)
Clinical benefit rate (CBR) in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK4/6 inhibitor response
CBR is defined as the total number of patients who achieve a complete response, partial response, or stable disease for 6 months or more from day 1 (D1) cycle 1 (C1). Comparisons between paired outcomes will be completed using the paired t-test or Wilcoxon signed-rank test for continuous parameters of interest, or McNemar's Chi-square test for categorical parameters of interest.
Measured: At day 28 of cycles 1 and 3
Progression free survival (PFS)
PFS is defined as the time from D1C1 to disease progression. Will be estimated using Kaplan-Meier method.
Measured: At 6, 12, and 18 months
CDK4/6 inhibitor response via TKa levels upon CDK4/6 inhibitor dose reductions or changes in CDK4/6 inhibitor regimen due to adverse events
Will estimate the two-sided 95% exact CI using Clopper-Pearson method.
Measured: Up to 2 years
Comparison of CDK4/6 inhibitor response profiles across the three CDK 4/6 inhibitors
Will be completed using the paired t-test or Wilcoxon signed-rank test for continuous parameters of interest, or McNemar's Chi-square test for categorical parameters of interest.
Measured: Up to 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Aug 2024
- Study start5 Sep 2023
- Primary completion16 Sep 2025
- Study completion16 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Anatomic Stage IV Breast Cancer AJCC v8Studies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 34 participants (actual)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Responsible party
- Sponsor
- Investigators
- Mariya Rozenblit, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06572800
- Sponsor's protocol ID
- 2000033797
- Other IDs
- NCI-2024-01395, 2000033797, P30CA016359
- Status last verified
- Oct 2025
- First submitted
- 22 Aug 2024
- Last updated
- 8 Oct 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of DiviTum-TKa as a Biomarker Assay for CDK4/6 Inhibitor Medication Compliance and Drug-Drug Interaction Assessment in ER/PR Positive Metastatic Breast Cancer
- ClinicalTrials.gov ID
- NCT06572800
- Acronym / sponsor ID
- 2000033797
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 34 participants (actual)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Study start
- 5 Sep 2023 (actual)
- Primary completion
- 16 Sep 2025 (actual)
- Study completion
- 16 Sep 2025 (actual)
- First posted
- 27 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This clinical trial assesses whether using a test developed by DiviTum can identify optimal levels of CDK 4/6 inhibitor medications in the blood and whether assessing medical compliance and drug-drug interactions can optimize (improve) these levels in patients with estrogen receptor (ER) or progesterone receptor (PR) positive, and human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic) and are receiving CDK 4/6 inhibitors. CDK4/6 inhibitors in combination with endocrine therapy (ET) is first line treatment for metastatic hormone positive (ER/PR positive) breast cancer (mBC). Thymidine kinase is a biomarker (biological molecule found in blood, other body fluids, or tissues that is a sign of a condition or disease) that reflects cell proliferation (an increase in the number of cells as a result of cell growth and cell division). DiviTum-thymidine kinase activity (TKa) is a Food and Drug Administration approved assay which showed that a TKa is associated with the decreased likelihood of disease progression within 30 days or 60 days post testing. Using the DiviTum-TKa may improve medication compliance and remove potential drug-drug interactions in patients with ER/PR positive HER2-negative MBC.
Detailed description
PRIMARY OBJECTIVE:
- To estimate the rate of improvement in CDK4/6 inhibitor response (i.e. moving from profile 3 to profiles 1 or 2) in cycles 2 and 3 after counseling for medication compliance and adjustment of potential deleterious drug-drug interactions.
SECONDARY OBJECTIVES:
- Estimate the rate of sub-optimal CDK 4/6 inhibitor response (profile 3) in patients with metastatic hormone positive breast cancer in cycle 1 of CDK4/6 inhibitor and endocrine therapy in the first line setting.
II. Compare clinical benefit rate (CBR) in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK4/6 inhibitor response after both cycles 1 and cycle 3.
III. Compare progression free survival (PFS) rates at 6 months (mo), 12 mo, 18 mo in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK 4/6 inhibitor response after both cycles 1 and cycle 3.
IV. Assess CDK4/6 inhibitor response via TKa levels upon CDK4/6 inhibitor dose reductions or changes in CDK4/6 inhibitor regimens.
- Compare CDK4/6 inhibitor response profiles across the three CDK 4/6 inhibitors among different patients and within the same patients if CDK4/6 inhibitor is changed throughout treatment course.
VI. Correlate TKa levels with tumor marker levels. VII. Assess plasma concentrations of CDK4/6 inhibitor drugs in patients with suboptimal TKa levels.
OUTLINE:
Patients undergo collection of blood samples per standard of care (SOC) on days 1, 15, and 28 of cycle 1, days 15 and 28 of cycle 2, days 15 and 28 of cycle 3, and day 28 of subsequent cycles for up to 12 cycles for analysis by DiviTum-TKa in the absence of disease progression or unacceptable toxicity.
After completion of study intervention, patients are followed up for 2 years.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Health services research (DiviTum-TKa) | Experimental | Device: DiviTum-TKaPatients undergo collection of blood samples per SOC on days 1, 15, and 28 of cycle 1, days 15 and 28 of cycle 2, days 15 and 28 of cycle 3, and day 28 of subsequent cycles for up to 12 cycles for analysis by DiviTum-TKa in the absence of disease progression or unacceptable toxicity. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Participants must have histologically confirmed metastatic ER-positive (> 10%), PR-positive or PR-negative, and HER2-negative (0 by immunohistochemistry [IHC] or if +1 or +2 by IHC, not amplified by fluorescence in situ hybridization [FISH]) breast cancer; ER positivity, PR positivity, and HER2 negativity as per the 2018 joint American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.
- Participants must be starting CDK4/6 inhibitor and endocrine therapy as part of first-line therapy per standard of care and be previously CDK4/6 inhibitor-naïve.
- Participants must be enrolled prior to starting CDK4/6 inhibitor therapy.
- Participants must be ≥ 18 years of age.
- Participants must have an Eastern Cooperative Oncology Group (ECOG) Performance Status < 3.
Key exclusion criteria (3 listed)
- Participants without evidence of metastatic disease prior to registration.
- Participants with prior use of CDK4/6 inhibitor therapy.
- Participants who are unable to provide informed consent for the trial.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DiviTum-TKaAnalyze blood samples by DiviTum-TKa | Device | Health services research (DiviTum-TKa) |
Primary outcome
Proportion of patients with thymidine kinase activity (TKa) values that switch from profile 3 to profile 1 or 2 after medication compliance and drug-drug interaction assessment
Time frame: Immediately following counseling for medication compliance and adjustment of potential deleterious drug-drug interactions
Will be estimated using the two-sided 95% exact confidence interval (CI) using Clopper-Pearson method.
Rate of improvement in CDK4/6 inhibitor response (i.e. moving from profile 3 to profiles 1 or 2)
Time frame: At day 28 of cycles 2 and 3 immediately following counselling for medication compliance and removing potential deleterious drug-drug interactions
Will be estimated using the two-sided 95% exact CI using Clopper-Pearson method.
4 secondary outcomes
Clinical benefit rate (CBR) in patients with sub-optimal (profile 3) and optimal (profiles 1 and 2) CDK4/6 inhibitor response
Time frame: At day 28 of cycles 1 and 3
Progression free survival (PFS)
Time frame: At 6, 12, and 18 months
CDK4/6 inhibitor response via TKa levels upon CDK4/6 inhibitor dose reductions or changes in CDK4/6 inhibitor regimen due to adverse events
Time frame: Up to 2 years
Comparison of CDK4/6 inhibitor response profiles across the three CDK 4/6 inhibitors
Time frame: Up to 2 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Oct 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mariya Rozenblit principal investigator
Yale University
18 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing DiviTum-TKa in people with Anatomic Stage IV Breast Cancer AJCC v8 and Metastatic HER2-Negative Breast Carcinoma, run by Yale University at 18 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 18 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of patients with thymidine kinase activity (TKa) values that switch from profile 3 to profile 1 or 2 after medication compliance and drug-drug interaction assessment (time frame: Immediately following counseling for medication compliance and adjustment of potential deleterious drug-drug interactions). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2025.