Immunotherapy drug keytruda takes on mysterious cancers of unknown origin

NCT ID NCT03391973

First seen Jul 02, 2026 · Last updated Jul 02, 2026

Summary

This phase 2 trial is investigating whether the immunotherapy drug pembrolizumab (Keytruda) can help people with a rare and aggressive cancer called carcinoma of unknown primary (CUP), where doctors cannot find where the cancer started. Participants have not received prior treatment and have a poor prognosis. They receive pembrolizumab by IV every three weeks for up to 24 months. The study aims to see if the drug can shrink tumors or slow the disease.

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)

What this could lead to

If it works, this could offer a new treatment option for people with a hard-to-treat cancer where the original site is unknown.

What could go wrong

This is a small, early-phase trial with no control group, so results may not apply broadly. Pembrolizumab can cause immune-related side effects.

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.

cancer of unknown primary site Neoplasms, Unknown Primary

As listed by the trial registrant

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

More trials for these conditions

Other studies related to the condition(s) this trial covers.

Contacts and locations

Locations

  • Cross Cancer Institute

    Edmonton, Alberta, Canada

  • Ottawa Hospital Cancer Centre

    Ottawa, Ontario, Canada

  • Tom Baker Cancer Centre

    Calgary, Alberta, T2N 4N2, Canada