Beam Therapeutics Inc. announced the first patient was treated with BEAM-302, an investigational in vivo base editing medicine designed to precisely correct the underlying cause of severe alpha-1 antitrypsin deficiency (AATD), that is currently being evaluated in a Phase 1/2 clinical trial. BEAM-302 is being evaluated in an open-label, dose-escalation Phase 1/2 clinical trial that will investigate the safety, pharmacodynamics, pharmacokinetics and efficacy of BEAM-302. The study design includes a dose exploration portion followed by a dose expansion portion to identify the optimal dose to take forward in a pivotal study.