Gut bacteria boosts cancer drug? early trial hints at possibility

NCT ID NCT03595683

First seen Jun 24, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tested whether taking a pill containing gut bacteria (EDP1503) could help the immunotherapy drug pembrolizumab (Keytruda) work better in people with advanced melanoma. The trial included two groups: those who had never received anti-PD1 therapy and those whose cancer had stopped responding to it. Only 8 people enrolled before the study was stopped early, so the results are very limited.

What this could mean

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

Active substance

pembrolizumab (Keytruda) and EDP1503 (a gut bacteria pill)

What this could lead to

If it works, this could point toward a way to make standard immunotherapy more effective for advanced melanoma by using gut bacteria.

What could go wrong

This was a very small, early-phase study that was terminated early, so results are limited. It is unclear if the combination is safe or effective, and it may not work for everyone.

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.

melanoma metastatic melanoma

As listed by the trial registrant

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

Contacts and locations

Locations

  • University of Chicago Medical Center

    Chicago, Illinois, 60637, United States