Blood test could help personalize breast cancer therapy

NCT ID NCT05977036

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tests whether a blood test measuring thymidine kinase activity (TKa) can help doctors decide early if a patient's breast cancer treatment is working. Patients with HR+ HER2- metastatic breast cancer start standard therapy with a CDK4/6 inhibitor and endocrine therapy. If the blood test at day 15 shows the treatment isn't suppressing TKa, patients switch to a different therapy. The goal is to see if this early switch improves how long the cancer stays under control.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

CDK4/6 inhibitor plus endocrine therapy

What this could lead to

If successful, this could show that a simple blood test helps doctors choose the right treatment earlier, potentially improving how long the cancer is controlled.

What could go wrong

This is a small, early-phase study (65 people) without a control group, so results may not apply broadly. The blood test may not reliably predict treatment response.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

breast cancer breast carcinoma breast neoplasm hormone receptor-positive breast cancer

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Study contacts

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

Locations

  • Washington University School of Medicine

    RECRUITING

    St Louis, Missouri, 63110, United States

    Contact

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

    Contact

    Contact

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