NCT04968964 · Washington University School of Medicine
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
What this study is about
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.
View original scientific description
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.
Interventions
DEVICE
DiviTum® TKa assay
-Determines serum enzymatic activity of TK1
OTHER
Study Care Plans
-Study Care Plans will be completed prior to and post release of serum DiviTum® TKa value
Primary outcome measures
Any physician-reported intended change in imaging testing interval identified on the study care plan post receipt of DiviTUM® TKa value
Time frame: Within the first 48-week period of study participation
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- - Patients:
- Diagnosis of metastatic or advanced resectable invasive breast cancer that is hormone receptor-positive (HR+) and HER2-negative. Tumor assessment by radiographic imaging will be performed within 4 weeks of baseline study visit.
- Cohort 1 only: Scheduled to initiate standard of care first-line combination therapy with any FDA-approved endocrine therapy plus any FDA-approved CDK 4/6 inhibitor (palbociclib, ribociclib, or abemaciclib) for the stated diagnosis at the time of study enrollment. Type of endocrine therapy and CDK 4/6 inhibitor will be documented. Patients may also be eligible if:
- Patients were treated with and progressed on prior endocrine therapy monotherapy in the metastatic setting, OR
- Patients initiated endocrine therapy alone with ultimate intention to add CDK 4/6 inhibitor therapy, OR
- Patients recurred on adjuvant endocrine therapy monotherapy and are scheduled to receive next line endocrine therapy combined with CDK 4/6 inhibitor. Patients may have also received CDK 4/6 inhibitor therapy in the adjuvant setting provided therapy completion occurred greater than 12 months prior to study enrollment.
- Cohort 2 only: Currently receiving first-line combination therapy with any FDA-approved endocrine therapy plus any FDA-approved CDK 4/6 inhibitor (palbociclib, ribociclib, or abemaciclib). Changes in endocrine therapy or CDK 4/6 inhibitor agent during first-line combination therapy are permitted as long as change was not performed due to progressive disease. CDK 4/6 inhibitor must have been initiated within 24 months of study enrollment, and patient must have at least stable disease (no progression) on such therapy for a minimum of 12 weeks prior to enrollment as determined by radiographic studies as deemed appropriate by the treating physician. Type of endocrine therapy and CDK 4/6 inhibitor will be documented. Patients may also be eligible if they are receiving next line endocrine therapy plus CDK 4/6 inhibitor therapy following:
- Progression on prior endocrine therapy monotherapy in the metastatic setting, OR
- Recurrence on adjuvant endocrine therapy monotherapy. Patients may have also received CDK 4/6 inhibitor therapy in the adjuvant setting provided therapy completion occurred greater than 12 months prior to study enrollment.
- Any prior therapy for early stage breast cancer is allowed, including endocrine therapy and chemotherapy.
- At least 18 years of age.
- Life expectancy \> 6 months.
- 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).
- Currently being treated at Siteman Cancer Center by a medical oncologist participating in this trial.
Exclusion criteria
- - Patients:
- Receipt of any prior cytotoxic chemotherapy line for metastatic disease. There will be no limited to chemotherapy use in the neoadjuvant or adjuvant setting.
- Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the protocol assessments or analyses are eligible for this trial as determined by treating physician and with agreement by Principal Investigator
- 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 invasive breast cancer
- Willing to complete Study Care Plans on a serial basis during participation
Where
- St Louis, Missouri
Collaborators
Biovica
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 6, 2026 · Source of record for eligibility and locations