Microbiotica presented new data on the mechanism of action of MB097, a clinical-stage drug candidate being developed as a co-therapy in combination with KEYTRUDA® (pembrolizumab) in patients with advanced melanoma
Data presented at AACR IO meeting in Los Angeles
Cambridge, UK – 26 February 2025: Microbiotica, a clinical-stage biopharma company developing a pipeline of oral precision microbiome medicines called live biotherapeutic products (LBPs), has presented new data on the mechanism of action of MB097 at the American Association for Cancer Research AACR IO meeting held in Los Angeles, February 23-26. MB097 is an LBP in development as an adjunct to immune-oncology treatments such as MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy, KEYTRUDA® (pembrolizumab).
Dr Mat Robinson, Microbiotica’s Senior Vice-President of Research, presented data from new pre-clinical studies in a poster entitled “Clinical response to immune checkpoint inhibitors in melanoma is associated with distinct gut bacterial species that promote anti-tumor immunity by different mechanisms”. The poster can be accessed here (https://microbiotica.com/2025-aacr-poster)
The bacteria comprising MB097 were found to be associated with response to immune-oncology treatments, such as KEYTRUDA® (pembrolizumab), in multiple cohorts of melanoma patients. These new data demonstrate that the bacterial strains within MB097 can interact directly with dendritic cells to potently activate cytotoxic T lymphocytes (CTL). In addition, certain MB097 bacteria also produced metabolites that enhanced the tumor cell-killing potential of CTLs. One strain released metabolites that reversed the inhibitory effects of tumor-associated macrophages.
Mat Robinson, Microbiotica’s Senior VP of Research, said, “These data begin to identify the different mechanisms by which gut commensal bacteria drive immunotherapy response.”
MB097 is being tested in an international Phase Ib clinical study, in combination with KEYTRUDA® (pembrolizumab), MSD's anti-PD-1 therapy, in patients with cutaneous melanoma who have failed to respond to immunotherapies. Data readout expected by the end of 2025.
