Synlogic Bridging Study Data with Solid Oral Formulation of SYNB1618, a Synthetic Biotic Approach to Treat Phenylketonuria, Demonstrate Improved Tolerability over Early Liquid Formulation and Guide to Next Stage of Clinical Development

Synlogic, Inc. (Nasdaq: SYBX), a clinical stage company applying synthetic biology to beneficial microbes to develop novel, living medicines, today announced that data from the Company’s bridging study in healthy volunteers of a solid formulation of SYNB1618 support its continued development for the treatment of phenylketonuria (PKU). Synlogic expects to initiate a Phase 2 clinical trial of SYNB1618 to evaluate its potential to lower blood phenylalanine (Phe) in patients with PKU in the first half of 2020.

“We are pleased with the results of this study, which have allowed us to select a maximum tolerated dose of the solid, oral formulation of SYNB1618 to move into a Phase 2 clinical trial,” said Richard Riese, M.D., Ph.D., Synlogic’s chief medical officer. “Incorporating what we have learned, we expect to initiate a clinical trial in patients with PKU that will assess the Phe-lowering potential of SYNB1618 and confirm our modeling. We look forward to presenting the full data set from our bridging study at an appropriate scientific meeting, and to providing more detail regarding the Phase 2 clinical trial design at a later date.”

The bridging study’s primary objectives were to evaluate safety and tolerability of an optimized manufacturing process and solid formulation of SYNB1618 and its Phe-consuming activity in healthy volunteers, as determined by production of previously identified biomarkers. In addition to identifying a maximum tolerated dose of 2 x 10¹² live cells (5.3 x 10¹¹ colony forming units, or CFUs), the study demonstrated that a dose ramp improved SYNB1618 tolerability and that pH buffering was required for maximum Phe-consuming activity of the strain.

“Development of a solid oral formulation of a Synthetic Biotic medicine that is stable at room temperature and can be administered at home, is a major achievement for our platform and a meaningful innovation for SYNB1618. We are a step closer to providing a new therapeutic option that is suitable for all patients with PKU regardless of age or disease type,” said Aoife Brennan, M.B., B.Ch., Synlogic’s president and chief executive officer. “Data obtained in this study provide valuable information as we continue to advance SYNB1618 and other orally administered Synthetic Biotic medicines to address additional indications with high unmet medical need.”