SYN-118

SYN-118 is an oral small-molecule inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD), a key enzyme in the catabolic pathway of tyrosine, thereby reducing the breakdown of tyrosine, the metabolic precursor of dopamine, and potentially increasing dopaminergic tone in the brain for the treatment of Parkinson’s disease and other movement disorders. It was originally licensed by Synosia Therapeutics from Syngenta, with subsequent rights for non-orphan indications partnered to UCB, while an HPPD inhibitor with the same pharmacological class is marketed separately as nitisinone (Orfadin) for hereditary tyrosinemia, a non-competing indication. In early clinical studies, SYN-118 demonstrated good oral bioavailability and tolerability, but a Phase IIa trial in Parkinson’s disease showed no appreciable difference vs placebo on motor function, although some earlier open-label data suggested motor benefit, and there is no evidence of further late-stage development.