BEAM-304

BEAM-304 is an investigational in vivo base editing therapy developed by Beam Therapeutics for the treatment of phenylketonuria (PKU). PKU is a rare genetic metabolic disorder caused by deficiency of the enzyme phenylalanine hydroxylase (PAH), leading to the accumulation of toxic levels of phenylalanine. BEAM-304 uses a liver-targeting lipid nanoparticle (LNP) to deliver base editing reagents that precisely correct disease-causing mutations in the PAH gene, such as the common R408W variant. Administered as a one-time intravenous infusion, the therapy aims to provide a durable reduction in phenylalanine levels, potentially allowing patients to achieve normal metabolic function and dietary freedom. The program employs an innovative approach where multiple mutation-specific base editors are advanced within a single clinical program to address various prevalent PKU variants.