Testing an antibiotic with radiation therapy for advanced lung cancer

Plain-English translation of NCT03546829 on ClinicalTrials.gov ↗ · Source last updated January 2026 · Translation generated June 2026 · How we translate trials

Phase 1 — Testing in a small group (usually 20–80 people) to find a safe dose and watch for side effects.

What is this trial?

This study is testing whether — an antibiotic — combined with precision radiation therapy can safely help patients whose lung cancer has started growing again in a limited number of spots after their first round of cancer treatment. Researchers believe that might work alongside radiation to improve outcomes. Participants will receive the medication for a week before radiation starts and for a month after, while providing blood and stool samples so doctors can monitor safety.

When lung cancer comes back in just a few spots after initial immunotherapy or targeted drug treatment, doctors want to know if they can control it better by combining radiation with this medication. This trial is exploring a new approach to see if the medication makes the radiation therapy more effective and safe.

Do you qualify?

You likely qualify if…

you have non-small cell lung cancer that has started growing again in fewer than 5 spots after your first cancer treatment
your cancer progressed after receiving immunotherapy or a targeted drug therapy
you are scheduled to receive precise, high-dose radiation therapy to all areas where your cancer is growing
you are 18 years or older and able to give informed consent

You likely don't qualify if…

you have taken antibiotics, antivirals, antifungals, or antiparasite medications in the 4 weeks before starting the trial
you are currently taking daily anti-diarrheal medications or probiotics
you have an active infection or fever (oral temperature over 100°F)
you have untreated cancer that has spread to your brain or spinal fluid
you have a documented history of HIV, hepatitis B, or hepatitis C

What participation looks like

You will start taking one week before your radiation therapy begins, and continue it for one month after radiation starts. Throughout the study, you will have blood and stool samples collected at specific timepoints so researchers can monitor how the medication and radiation affect your body. Your participation involves receiving your radiation treatment as planned while taking the medication and providing these samples — typically a commitment of several weeks to a couple of months.

AI-generated summary from trial data · Jun 12, 2026 · Not medical advice

Trial locations(1 site)

United States

University of Pennsylvania, Philadelphia, Pennsylvania