Medications That Affect Microbiome May Influence Checkpoint Inhibitory Response

September 16, 2020 by Elisa Becze BA, ELS, Editor

Common classes of non-cancer medications that affect a patient’s microbiome are associated with increased or decreased survival with immune checkpoint inhibitor (ICI) drugs, researchers reported ( in study findings published in BMC Cancer.

In a retrospective analysis of 690 patients receiving ICIs for advanced cancer, researchers studied the relationship between the microbiome, ICI response, and various medications: antibiotics, corticosteroids, proton pump inhibitors, histamine receptor blockers, nonsteroidal anti-inflammatory drugs (NSAIDs), and statins.

They found that patients who took antibiotics or corticosteroids within 28 days of starting ICI therapy experienced reduced survival across all cancer types. Other medications showed significant associations with specific cancers, and some even appeared to increase survival. For example, histamine receptor blockers and NSAIDs were associated with decreased survival in sarcoma and non-small cell lung cancer, respectively; protein pump inhibitors and statins were positively associated with overall survival in sarcoma.

“A clear understanding of which microbes are important for ICI responses and in what cancers will require the collection of microbiome samples across a wide variety of clinical settings,” the researchers wrote ( “Medications that affect the microbiome given concomitantly with ICIs provide evidence for where microbes play a role. Further work is needed to identify which microbes are important and identify solutions to mitigate these effects and perhaps promote greater response to ICIs.”

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