Metastatic Breast CancerNCT05977036
BettER: Biomarker Driven Early Therapeutic Selection in Patients With HR+ HER2- Metastatic or Unresectable Breast Cancer
A study testing DiviTum® TKa assay in people with Metastatic Breast Cancer and Unresectable Breast Cancer, run by Washington University School of Medicine at 1 site in United States.
Trial summary
This is a prospective study to assess the impact of biomarker driven, early therapeutic switching and delayed imaging with the incorporation of DiviTum® serum TK1 activity ("DiviTum® TKa") in patients with hormone receptor (HR) positive, HER-2 negative metastatic or unresectable breast cancer receiving first-line or… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Metastatic Breast Cancer, Unresectable Breast Cancer
- What is being tested?
- DiviTum® TKa assay
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 145 participants
- Where
- 1 siteUnited States
- Study dates
- 25 Sep 2024to 30 Sep 2035
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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:
Show all 17Show fewer
- 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).
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Washington University School of Medicine
St Louis, Missouri, 63110
Katherine Clifton, M.D., 314-273-3712, k.clifton@wustl.edu
Katherine Clifton, M.D.
About this study
This is a prospective study to assess the impact of biomarker driven, early therapeutic switching and delayed imaging with the incorporation of DiviTum® serum TK1 activity ("DiviTum® TKa") in patients with hormone receptor (HR) positive, HER-2 negative metastatic or unresectable breast cancer receiving first-line or second-line treatment.
- Being tested
- DiviTum® TKa assay
- Keywords
- ER+ HER2- metastatic breast cancer, biomarkers, thymidine kinase
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DiviTum® TKa assayDevice
Will be utilized for determination of serum enzymatic activity of TK1 according to the manufacturer's instructions
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 1st line treatment | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 1 with suppressed TKa (defined as ≤ 145 DuA) at C1D15 will be allocated into Cohort A, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. These patients may be given an option to delay imaging if TKa continues to be suppressed at coinciding TKa draw and imaging time points. Receives: Device: DiviTum® TKa assay |
| Arm 1 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch to alternate therapy | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 1 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients who do switch therapies will be allocated into Cohort B, and the patient will have TKa samples drawn at initiation of next-line therapy and on the first day of subsequent cycles, until progression or end of active participation (EOAP), whichever occurs first. Receives: Device: DiviTum® TKa assay |
| Arm 1 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 1st line treatment | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 1 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients with unsuppressed TKa levels at C1D15 who do not switch therapies will be allocated into Cohort, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. Receives: Device: DiviTum® TKa assay |
| Arm 2 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 2nd line treatment | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 2 with suppressed TKa (defined as ≤ 145 DuA) at C1D15 will be allocated into Cohort A, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. These patients may be given an option to delay imaging if TKa continues to be suppressed at coinciding TKa draw and imaging time points. Receives: Device: DiviTum® TKa assay |
| Arm 2 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch from 2nd line to alternate therapy | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 2 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients who do switch therapies will be allocated into Cohort B, and the patient will have TKa samples drawn at initiation of next-line therapy and on the first day of subsequent cycles, until progression or end of active participation (EOAP), whichever occurs first. Receives: Device: DiviTum® TKa assay |
| Arm 2 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 2nd line treatment | Experimental | * Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars.
* Patients in Arm 2 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients with unsuppressed TKa levels at C1D15 who do not switch therapies will be allocated into Cohort, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. Receives: Device: DiviTum® TKa assay |
| Arm 3: Receiving 1st/2nd line treatment with any treatment other than CDK4/6i & endocrine therapy | Active comparator | Patients in Arm 3 will have TKa samples drawn at C2D1, C4D1, and every 3 months (+/- 2 weeks) thereafter (or at their physician's discretion), as well as at the time of clinical progression or end of active participation (EOAP), whichever occurs first. No recommendations for treatment or imaging will be made. Receives: Device: DiviTum® TKa assay |
| Physicians | No intervention | - Physicians will be asked to complete surveys as follows: * Physician Survey 1 for patients in Arm 1 Cohort A who have the option increase the scan timing interval between the C4D1 and C7D1 scan. * Physician Survey 2 for patients in Arms 1 and 2, Cohorts B and C who have the option to switch to alternate therapy. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression-free survival (PFS) in patients who remain on CKD4/6i (Arms 1 and 2, Cohort A)
PFS is defined as from the start date of receiving CDK4/6i to the date of progression, death, or last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Clinical benefit rate (CBR) in patients who remain on CDK4/6i (Arms 1 and 2, Cohort A)
CBR is defined as total number (or percentage) of patients who achieved a complete response, partial response, or had stable disease for 6 months or more.
Measured: Through completion of follow-up (estimated to be 7 years)
Progression-free survival (PFS2) in patients who switch to an alternate therapy (Arms 1 and 2, Cohort B)
PFS is defined as from the start date of receiving CDK4/6i to the date of progression on the alternate therapy, death, or last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Clinical benefit rate (CBR) in patients who switch to an alternate therapy (Arms 1 and 2, Cohort B)
CBR is defined as total number (or percentage) of patients who achieved a complete response, partial response, or had stable disease for 6 months or more.
Measured: Through completion of follow-up (estimated to be 7 years)
Secondary outcomes (12)
Feasibility of early therapeutic switching as measured by compliance rate (Arms 1 and 2, Cohorts B and C)
Compliance is defined as subset of physicians and patients following protocol recommendation to switch to next line of treatment
Measured: At cycle 1 day 15 (each cycle is 28 days)
Feasibility of delayed imaging as measured by compliance rate (Arm 1 Cohort A)
Compliance is defined as this subset of physicians and patients who delay restaging scans from C7D1 to C10D1.
Measured: At cycle 7 day 1 (each cycle is 28 days)
Baseline TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Clinical benefit is defined as SD for 16 weeks or longer, CR, or PR.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Clinical benefit is defined as SD for 16 weeks or longer, CR, or PR.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Clinical benefit is defined as SD for 16 weeks or longer, CR, or PR.
Measured: Through completion of follow-up (estimated to be 7 years)
Baseline TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
- PFS in patients with suppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression, death, or last follow-up.
- PFS in patients with unsuppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression on the alternate therapy, death, or last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
- PFS in patients with suppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression, death, or last follow-up.
- PFS in patients with unsuppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression on the alternate therapy, death, or last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
- PFS in patients with suppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression, death, or last follow-up.
- PFS in patients with unsuppressed TKa levels is defined as from the start date of receiving CDK4/6i to the date of progression on the alternate therapy, death, or last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Baseline TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
OS is defined as from the start date of receiving CDK4/6i (Arms 1 and 2) or non-CDK4/6i therapy (Arm 3) to the date of death or date of last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
OS is defined as from the start date of receiving CDK4/6i (Arms 1 and 2) or non-CDK4/6i therapy (Arm 3) to the date of death or date of last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
OS is defined as from the start date of receiving CDK4/6i (Arms 1 and 2) or non-CDK4/6i therapy (Arm 3) to the date of death or date of last follow-up.
Measured: Through completion of follow-up (estimated to be 7 years)
Number of patients with suppressed TKa levels at cycle 1 day 15 who have stable disease on subsequent disease assessments (Arms 1 and 2, Cohort A)
Measured: Through 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Aug 2023
- Study start25 Sep 2024
- Primary completion30 Sep 2035 (estimated)
- Study completion30 Sep 2035 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Breast CancerStudies of the same condition, open and under way.
- More trials run by Washington University School of MedicineThe 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
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 145 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Washington University School of Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- Biovica
- Responsible party
- Sponsor
- Investigators
- Katherine Clifton, M.D., Principal investigator, Washington University School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05977036
- Sponsor's protocol ID
- 202307176
- Status last verified
- Oct 2026
- First submitted
- 27 Jul 2023
- Last updated
- 9 Oct 2026
- 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 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- BettER: Biomarker Driven Early Therapeutic Selection in Patients With HR+ HER2- Metastatic or Unresectable Breast Cancer
- ClinicalTrials.gov ID
- NCT05977036
- Acronym / sponsor ID
- 202307176
- Keywords
- ER+ HER2- metastatic breast cancer, biomarkers, thymidine kinase
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 145 participants (estimated)
- Lead sponsor
- Washington University School of MedicineUniversity, hospital or other
- Collaborators
- Biovica
- Study start
- 25 Sep 2024 (actual)
- Primary completion
- 30 Sep 2035 (estimated)
- Study completion
- 30 Sep 2035 (estimated)
- First posted
- 4 Aug 2023 (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 is a prospective study to assess the impact of biomarker driven, early therapeutic switching and delayed imaging with the incorporation of DiviTum® serum TK1 activity ("DiviTum® TKa") in patients with hormone receptor (HR) positive, HER-2 negative metastatic or unresectable breast cancer receiving first-line or second-line treatment.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| Arm 1 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 1st line treatment | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 1 with suppressed TKa (defined as ≤ 145 DuA) at C1D15 will be allocated into Cohort A, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. These patients may be given an option to delay imaging if TKa continues to be suppressed at coinciding TKa draw and imaging time points. |
| Arm 1 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch to alternate therapy | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 1 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients who do switch therapies will be allocated into Cohort B, and the patient will have TKa samples drawn at initiation of next-line therapy and on the first day of subsequent cycles, until progression or end of active participation (EOAP), whichever occurs first. |
| Arm 1 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 1st line treatment | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 1 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients with unsuppressed TKa levels at C1D15 who do not switch therapies will be allocated into Cohort, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. |
| Arm 2 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 2nd line treatment | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 2 with suppressed TKa (defined as ≤ 145 DuA) at C1D15 will be allocated into Cohort A, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. These patients may be given an option to delay imaging if TKa continues to be suppressed at coinciding TKa draw and imaging time points. |
| Arm 2 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch from 2nd line to alternate therapy | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 2 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients who do switch therapies will be allocated into Cohort B, and the patient will have TKa samples drawn at initiation of next-line therapy and on the first day of subsequent cycles, until progression or end of active participation (EOAP), whichever occurs first. |
| Arm 2 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 2nd line treatment | Experimental | Device: DiviTum® TKa assay* Blood serum samples will be collected and analyzed using DiviTum® TKa prior to starting treatment, during treatment, and during follow-up as specified on the calendars. * Patients in Arm 2 with unsuppressed TKa (defined as >145 DuA) at C1D15 will be recommended to switch to an alternative therapy. Patients with unsuppressed TKa levels at C1D15 who do not switch therapies will be allocated into Cohort, and the patient will continue on their CDK4/6i and endocrine therapy and undergo TKa draws at C2D1, C4D1, C7D1, and then approximately every 3 months. |
| Arm 3: Receiving 1st/2nd line treatment with any treatment other than CDK4/6i & endocrine therapy | Active comparator | Device: DiviTum® TKa assayPatients in Arm 3 will have TKa samples drawn at C2D1, C4D1, and every 3 months (+/- 2 weeks) thereafter (or at their physician's discretion), as well as at the time of clinical progression or end of active participation (EOAP), whichever occurs first. No recommendations for treatment or imaging will be made. |
| Physicians | No intervention | –- Physicians will be asked to complete surveys as follows: * Physician Survey 1 for patients in Arm 1 Cohort A who have the option increase the scan timing interval between the C4D1 and C7D1 scan. * Physician Survey 2 for patients in Arms 1 and 2, Cohorts B and C who have the option to switch to alternate therapy. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (17 listed)
- 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:
- 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:
- Measurable or non-measurable disease per RECIST v1.1.
- At least 18 years of age.
Key exclusion criteria (7 listed)
- 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.
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® TKa assayWill be utilized for determination of serum enzymatic activity of TK1 according to the manufacturer's instructions | Device | Arm 1 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 1st line treatment, Arm 1 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch to alternate therapy, Arm 1 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 1st line treatment, Arm 2 Cohort A: Suppressed TKa at Cycle 1 Day 15-continue 2nd line treatment, Arm 2 Cohort B: Lack of Tka suppression at Cycle 1 Day 15-switch from 2nd line to alternate therapy, Arm 2 Cohort C: Lack of TKa suppression at Cycle 1 Day 15-remain on same 2nd line treatment, Arm 3: Receiving 1st/2nd line treatment with any treatment other than CDK4/6i & endocrine therapy |
Primary outcome
Progression-free survival (PFS) in patients who remain on CKD4/6i (Arms 1 and 2, Cohort A)
Time frame: Through completion of follow-up (estimated to be 7 years)
PFS is defined as from the start date of receiving CDK4/6i to the date of progression, death, or last follow-up.
Clinical benefit rate (CBR) in patients who remain on CDK4/6i (Arms 1 and 2, Cohort A)
Time frame: Through completion of follow-up (estimated to be 7 years)
CBR is defined as total number (or percentage) of patients who achieved a complete response, partial response, or had stable disease for 6 months or more.
Progression-free survival (PFS2) in patients who switch to an alternate therapy (Arms 1 and 2, Cohort B)
Time frame: Through completion of follow-up (estimated to be 7 years)
PFS is defined as from the start date of receiving CDK4/6i to the date of progression on the alternate therapy, death, or last follow-up.
Clinical benefit rate (CBR) in patients who switch to an alternate therapy (Arms 1 and 2, Cohort B)
Time frame: Through completion of follow-up (estimated to be 7 years)
CBR is defined as total number (or percentage) of patients who achieved a complete response, partial response, or had stable disease for 6 months or more.
12 secondary outcomes
Feasibility of early therapeutic switching as measured by compliance rate (Arms 1 and 2, Cohorts B and C)
Time frame: At cycle 1 day 15 (each cycle is 28 days)
Feasibility of delayed imaging as measured by compliance rate (Arm 1 Cohort A)
Time frame: At cycle 7 day 1 (each cycle is 28 days)
Baseline TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict clinical benefit on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Baseline TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict progression-free survival (PFS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Baseline TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 1 day 15 TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Cycle 2 day 1 TKa levels to predict overall survival (OS) on first-line CDK4/6i and on later lines of therapy (All Arms and Cohorts)
Time frame: Through completion of follow-up (estimated to be 7 years)
Number of patients with suppressed TKa levels at cycle 1 day 15 who have stable disease on subsequent disease assessments (Arms 1 and 2, Cohort A)
Time frame: Through 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Oct 2026.
- Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of MedicineLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Metastatic Breast Cancer
RecruitingObservational study
Collection of CSF Samples From Participants With Metastatic Triple Negative Breast Cancer (TNBC) and HER2+ Breast Cancer With no Prior History Nor Active Radiographically Detectable Brain Metastases
Breast Cancer, Breast Carcinoma
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.
Katherine Clifton, M.D. principal investigator
Washington University School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing DiviTum® TKa assay in people with Metastatic Breast Cancer and Unresectable Breast Cancer, run by Washington University School of Medicine at 1 site 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 17 inclusion and 7 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: looking for participants now, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Katherine Clifton, M.D. (314-273-3712, k.clifton@wustl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Progression-free survival (PFS) in patients who remain on CKD4/6i (Arms 1 and 2, Cohort A) (time frame: Through completion of follow-up (estimated to be 7 years)). The study lists 4 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 9 Oct 2026.