We evaluated the ability of the EXL01 strain to restore the anti-tumour effects of the anti-PDL1 antibody in the MCA205 tumour-bearing mouse model, with a dysregulated microbiota induced through antibiotic administration. The study was performed on an in vivo syngeneic subcutaneously implanted MCA205 tumour-bearing mouse model.
Antibiotic administration clearly limited the anti-PDL1 mediated anti-tumour effect, thus highlighting the critical role of the microbiota in response to immune checkpoint inhibitors. EXL01 partially restored anti-PDL1 efficacy as highlighted through a significantly higher number of animals with reduced tumour volumes (Figure 1A), and a significantly higher survival benefit (Figure 1B).
Figure 1: Tumour volumes (A) and survival progression (B) in syngeneic subcutaneously implanted MCA205 tumour-bearing mice with a dysregulated microbiota induced through antibiotic administration following the administration of anti-PDL1 in combination with EXL01 through oral gavage.