How a cancer medication affects other drugs in your body

Plain-English translation of NCT07704658 on ClinicalTrials.gov ↗ · Source last updated July 2026 · Translation generated July 2026 · How we translate trials

Phase 4 — The treatment has already been approved. Researchers are tracking how it works in a large number of people over time.

What is this trial?

This trial is testing how (Gavreto), a cancer medication, affects the way your body processes other medications you might be taking. Researchers want to understand whether this medication speeds up, slows down, or doesn't change how your body breaks down common drugs and hormonal birth control. This information helps doctors safely prescribe alongside other treatments.

When you take multiple medications at the same time, they can interact with each other in ways that make them more or less effective. Doctors need to know exactly how this medication affects your body's ability to process other drugs so they can adjust doses safely and prevent harmful interactions.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been diagnosed with an advanced or metastatic solid tumor with a RET mutation or fusion that has not responded to standard treatments
you have recovered from side effects of prior cancer treatment to mild levels or better
you have adequate organ function (healthy enough blood counts, liver, and kidney function)
you have not had major surgery, radiation, chemotherapy, or other cancer treatments within the last 4–6 weeks

You likely don't qualify if…

you have had a recent lung inflammation or pneumonitis (within the last 12 months)
you have a stomach or digestive condition that would prevent you from absorbing medications properly
you have significantly abnormal blood tests, heart rhythm problems, or other medical conditions that could interfere with the study
you are a woman of childbearing age (the study requires women to be postmenopausal or surgically sterile)

What participation looks like

You will take along with special test drugs (called probe substrates) that help researchers see how your body processes medications. The study involves blood tests to measure drug levels in your system at different times. If you are female, you may also take a hormonal birth control probe to see how the medication affects it. The study is small—only 12 people total—and takes place at multiple medical centers.

AI-generated summary from trial data · Jul 15, 2026 · Not medical advice

Trial locations(2 sites)

Spain

Hospital Universitario San Pedro, Logroño, La Rioja

Hospital Universitario HM Sanchinarro, Madrid