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KEYNOTE-158: What the Cancer Trial Found

KEYNOTE-158 tested pembrolizumab in tumor-mutational-burden-high cancers in cancer, measuring objective response. Plain-language summary of a result widely described as practice-influencing — and what it doesn't mean.

By Cancer Explained Editorial SystemPublished July 12, 2026

Original commentary from the Cancer Explained editorial team.

Please note: this page is educational only — it is not medical advice, and it does not speculate about anyone’s health beyond reliable public reporting. For questions about your own health, talk with your healthcare team.

In brief

KEYNOTE-158 was phase 2, basket trial in cancer that compared pembrolizumab in tumor-mutational-burden-high cancers and measured objective response. It reported a result widely described as practice-influencing.

Trial at a glance

FieldDetail
TrialKEYNOTE-158
IdentifierNot recorded here
PhasePhase 2
Designphase 2, basket trial
Cancer typeCancer
Comparatorpembrolizumab in tumor-mutational-burden-high cancers
Primary endpointobjective response
Reported resultA result widely described as practice-influencing

Who took part

The trial enrolled the population described in its report for cancer.

The main result

The trial's main finding concerned objective response: KEYNOTE-158 reported a result widely described as practice-influencing. Full numbers, follow-up, and statistical detail are held for verification against the peer-reviewed report or trial registry.

What the result means

Results like this help shape research and, sometimes, care — but a trial's finding is one piece of evidence, tied to the specific people and design it used.

What to keep in perspective

  • A positive trial does not automatically mean a treatment is approved or available; approval and access are separate steps.
  • A response or progression-free-survival result is not the same as living longer; overall-survival data may take longer to mature.
  • Trial participants are selected by specific criteria, so results may not apply to everyone with this cancer.

If this is relevant to you, questions to ask

  • Does this apply to my specific cancer type and situation?
  • Is this treatment approved and available, or still investigational?
  • What are the main side effects, and how would they be managed?

Sources

This article was written from the sources below, which were checked on the source-check date shown above.

How this article was prepared

Prepared by Cancer Explained's AI-assisted editorial system and checked against the sources listed below. This article has not been reviewed by a healthcare professional unless a named reviewer is specifically shown.

Cancer Explained is published by the National Cancer Information Foundation as a nonprofit-oriented public-interest education project. It is not a diagnostic service, does not recommend treatments, and is not for emergencies.

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