New Melanoma Therapy Shows Early Promise in Phase 1b
A bacterial therapy combined with immunotherapy helped some patients with advanced melanoma in a small, early-stage trial.
Updated on Oct. 26, 2026 in Cancer
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Microbiotica presented Phase 1b trial results showing that a novel oral bacterial therapy, MB097, combined with KEYTRUDA may benefit patients with advanced melanoma. The study examined outcomes in 41 participants who were previously unresponsive to standard anti-PD-1 treatments.
Why it matters
Researchers are investigating whether modifying the gut microbiome with live therapeutic bacteria can overcome resistance to traditional immunotherapy. This approach seeks to improve clinical response rates for patients who no longer benefit from established cancer treatments.
In a Phase 1b trial of 41 patients with advanced melanoma refractory to anti-PD-1 therapy, investigators tested the combination of MB097 and KEYTRUDA. Findings indicate a 14% response rate for those receiving vancomycin preconditioning compared to 10% for those who did not.
The players
Microbiotica
A biotechnology company headquartered in Cambridge, UK, focused on developing therapies derived from the human gut microbiome.
KEYTRUDA
A widely used anti-PD-1 immunotherapy drug that helps the immune system detect and attack cancer cells.
The details
MB097 is an oral, once-daily medication containing nine distinct bacterial strains designed to alter the gut environment. By administering vancomycin prior to treatment, researchers aimed to clear space in the microbiome to facilitate better bacterial engraftment. Participants underwent 24 weeks of combined treatment with MB097 and KEYTRUDA to evaluate safety and clinical activity.
Timeline
23-27 October 2026: The ESMO Congress 2026 was held in Madrid.
24 October 2026: Clinical trial findings were presented to the scientific community.
26 October 2026: The official data announcement was published by the manufacturer.
Health Landscape
The MELODY-1 clinical trial represents an emerging research effort to enhance immunotherapy efficacy by targeting the gut microbiome. This approach aims to address treatment resistance in advanced cancer, moving beyond existing standard-of-care protocols.
These preliminary findings are intended for clinical research purposes and do not represent an approved treatment for melanoma patients. It is worth discussing with your doctor whether you are eligible for experimental immunotherapy trials if you have refractory advanced melanoma.
The takeaway
Early data suggests that modulating the gut microbiome might help some patients respond to cancer immunotherapy where they previously could not. Patients interested in these experimental options should consult with their oncologist about current clinical trial enrollment opportunities.
Further reading
For more information on current developments in immunotherapy and research, visit our Cancer section.
More information
View the clinical study registry details for complete information on this trial.
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