Synlogic
Pioneer synthetic biology biopharmaceutical company engineering bacteria as living medicines, now winding down after a pivotal trial setback.
Synlogic Investor Relations (Official Site)Synlogic is a Boston-based biopharmaceutical company founded in 2014 and listed on Nasdaq (SYBX) following a 2017 merger with Mirna Therapeutics. It was the first synthetic biology company focused entirely on therapeutics, pioneering a modality it called Synthetic Biotic medicines — orally administered, GI-restricted formulations based on genetically engineered Escherichia coli Nissle designed to metabolize or synthesize specific biological targets in the body.
The company's pipeline centered on rare metabolic diseases, including its lead program labafenogene marselecobac (SYNB1934) for phenylketonuria (PKU), SYNB1353 for classical homocystinuria (HCU), and additional candidates targeting enteric hyperoxaluria, gout, and cystinuria. Its platform used a reproducible, modular synthetic biology approach to create new enzymatic pathways addressing validated disease biology.
In February 2024, Synlogic voluntarily halted its pivotal Phase 3 Synpheny-3 trial for PKU after an internal review indicated it was unlikely to meet its primary endpoint — not due to safety concerns. The company subsequently announced a plan to cease operations, cut its workforce by more than 90%, and saw CEO Dr. Aoife Brennan step down. As of Q3 2024, Synlogic held approximately $19.4 million in cash and was retaining Lucid Capital Markets to explore strategic options including acquisition or merger, with only one full-time employee remaining.