CAMBRIDGE, United Kingdom, Oct. 26, 2026 (GLOBE NEWSWIRE) — Microbiotica, a clinical-stage biopharma company developing a pipeline of precision microbiome medicines, has presented clinical data with encouraging efficacy from its Phase 1b MELODY-1 trial of MB097, its precision microbiome therapeutic for patients with advanced melanoma, at the European Society for Medical Oncology (ESMO) Congress 2026 taking place 23-27 October 2026, in Madrid, Spain.

Key findings presented at ESMO 2026

  • Poster presentation outlined clinical data from the Phase 1b MELODY-1 trial, which met all its primary and secondary endpoints.
  • MB097 was safe and well tolerated in combination with KEYTRUDA® (pembrolizumab), with no serious adverse effects related to MB097.
  • The nine-strain bacterial consortium demonstrated rapid, robust and persistent engraftment, particularly in patients receiving vancomycin preconditioning.
  • Three of 21 patients (14%) in the vancomycin-preconditioning arm achieved an objective response, despite being refractory to anti-PD-1 therapy.
  • Two of 20 patients (10%) in the non-vancomycin preconditioning arm achieved an objective response consistent with lower engraftment.
  • The responses in the vancomycin arm were deep with all responders achieving >75% reduction in target lesion dimensions and one complete response.

Professor Paolo Ascierto, Director of the Department of Skin Cancers, Cancer Immunotherapy and Development Therapeutics at University of Naples Federico II, Istituto Nazionale Tumori IRCCS Fondazione G. Pascale, Naples, Italy and a National Co-ordinating Investigator for the MELODY-1 study, said: “The advanced melanoma patients enrolled in MELODY-1 had recently received anti-PD-1 therapy but continued to experience disease progression. Many had received multiple prior lines of treatment, including combination immune checkpoint inhibitor regimens, without achieving a meaningful clinical benefit. This represents a particularly challenging patient population with limited therapeutic options. It is therefore encouraging to observe clinically meaningful responses, including deep tumour regressions, suggesting that modulation of the gut microbiome with MB097 may help restore sensitivity to pembrolizumab in patients previously refractory to anti-PD-1 therapy. These findings provide an important early clinical proof-of-concept for microbiome-based strategies aimed at enhancing the effectiveness of cancer immunotherapy and warrant further investigation in larger clinical studies.”

MB097 is an oral, once-daily live therapeutic comprising a consortium of nine bacterial strains identified through the analysis of four clinical studies in the US and Europe using Microbiotica’s genomics-driven microbiome platform. MB097 is being evaluated in an international Phase 1b clinical study (MELODY-1) which is assessing MB097’s safety and tolerability when administered once daily in combination with MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy KEYTRUDA® (pembrolizumab), in patients with advanced melanoma. The trial recruited 41 patients with advanced melanoma whose cancer had failed to respond at any time to treatment with anti-PD-1 antibody therapy (primary refractory) at clinical centres in the UK, France, Italy and Spain.

To assess the effect of antibiotic preconditioning on bacterial engraftment and clinical outcome, patients were randomised to receive either five days of vancomycin (125 mg four times daily), followed by a two-day washout period (n=21), or no antibiotic preconditioning (n=20). Patients in both arms were then treated with MB097 and KEYTRUDA for 24 weeks after which patients with disease control were eligible for continued treatment with KEYTRUDA. All 41 patients have completed the MB097 treatment phase and 12-week safety follow-up.

Robert Tansley, Chief Medical Officer of Microbiotica, said: “Growing evidence highlights the role of the gut microbiome in patients’ responses to immune checkpoint inhibitors, particularly anti-PD-1 therapies. The data presented at ESMO from our Phase 1b MELODY-1 study demonstrates that MB097 was safe and well tolerated in combination with KEYTRUDA, with robust, persistent engraftment of the bacterial consortium and encouraging clinical responses in this challenging patient population. These findings support further evaluation of MB097, and we look forward to generating additional data from the extension phase as we continue to investigate its potential for patients with melanoma who do not respond to anti-PD-1 therapy.”

Poster details

Section: Investigational immunotherapy
Title: Safety and efficacy of MB097, a precision live biotherapeutic product, combined with pembrolizumab in anti-PD1 primary resistant advanced melanoma; a phase 1B first-in-human study
Presentation Number: 1983P
Date: 24 October 2026
Time: 12:00-12:45
Presenter: Paolo A. Ascierto

Study details: ClinicalTrials.gov NCT06540391

For media enquiries, please contact:

Microbiotica
Tim Sharpington
tsharpington@microbiotica.com

FTI Consulting
Ben Atwell, Simon Conway, Natalie Garland-Collins
microbiotica@fticonsulting.com
+44 (0) 20 3727 1000

Notes to editors

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

About Microbiotica

Microbiotica is a private, clinical-stage, biopharma company developing oral precision microbiome medicines called live biotherapeutic products (LBPs). Its lead programme, MB310, is being developed for ulcerative colitis and has demonstrated promising clinical activity and a favourable safety profile in a Phase 1b study. Microbiotica is also advancing a pipeline of immuno-oncology programmes, including MB097 in combination with KEYTRUDA® (pembrolizumab) for advanced melanoma, which has met its trial endpoints and is progressing through a Phase 1b extension phase.

Microbiotica’s proprietary, genomics-driven microbiome profiling platform enables precision identification of bacteria associated with favourable clinical trial outcomes in specific patient populations. This clinical-data led approach informs the selection of bacterial strains for therapeutic development with the potential to improve the likelihood of clinical success.

Spun out of the Wellcome Sanger Institute in 2016, the Company is based in purpose-built facilities at the Chesterford Research Park near Cambridge, UK. Microbiotica is backed by British Business Bank, Cambridge Innovation Capital, Flerie Invest, IP Group plc, Seventure Partners and Tencent. The Company has also received financial support from the US-based Crohn’s and Colitis Foundation.

For more information, please visit www.microbiotica.com, and follow us on LinkedIn.


Primary Logo

Media gallery

About The Author
Microbiotica