Microbiome therapeutics company Seres Therapeutics Inc (NASDAQ: MCRB) announced on Tuesday that it has finished patient enrollment for the Phase 1B trial of SER-155 in Allogeneic Hematopoietic Stem Cell Transplantation (Allo HSCT) patients.

SER-155 aims to reduce enteric-derived infections and bloodstream infections, including those with antibiotic resistance, in immunocompromised patients. Enrollment for the placebo-controlled Cohort 2 is now complete.

The Phase 1B trial is conducted across 13 clinical centres in the US, including Memorial Sloan Kettering, with Cohort 1 demonstrating favorable tolerability and successful drug bacteria engraftment.

SER-155 utilises Seres' reverse translation discovery platform and has received FDA Fast Track Designation. It is designed to prevent bacterial pathogen colonization and enhance GI tract integrity, potentially reducing infections and GvHD incidence.

Seres Therapeutics' lead program VOWST is approved by the FDA for preventing recurrence of C. difficile infection.