February 10, 2020

LogicBio Therapeutics, Inc. (Nasdaq:LOGC), a genome editing company focused on developing medicines to durably treat rare diseases in pediatric patients, today announced that the U.S. Food and Drug Administration (FDA) has placed a clinical hold on the Investigational New Drug (IND) submission for LB-001 for the treatment of methylmalonic acidemia (MMA) pending the resolution of certain clinical and nonclinical questions. The Company submitted the IND in January 2020 to support the initiation of a Phase 1/2 clinical trial in patients with MMA. LogicBio expects that the FDA questions will be provided in writing within 30 days. LogicBio plans to work closely with the FDA to resolve these questions as quickly as possible.

About LB-001

LB-001 is an investigational pediatric genome editing therapy based on LogicBio’s GeneRide™ technology. GeneRide enables site-specific integration and lifelong expression of therapeutic transgenes, without the use of exogenous promoters or nucleases. LB-001 is designed to incorporate a functioning version of the faulty human methylmalonyl-COA mutase (MMUT) gene into the genome of MMA patients. LogicBio has demonstrated preclinical proof-of-concept of GeneRide in multiple animal models of the disease, improving survival and reversing disease pathology. In preclinical MMA models, LogicBio has shown that cells into which GeneRide has inserted a transgene demonstrate a selective survival advantage over cells not expressing the transgene. LB-001 has received both orphan drug and rare pediatric disease designations from the U.S. Food and Drug Administration