Treatment with 60 mg of BEAM-302 Led to Mean Steady-state Total AAT Level of 16.1 µM and All Patients Consistently and Durably Above the 11 µM Protective AAT Threshold with up to 12 Months of Follow-up

Corrected M-AAT Comprised 94% of Total AAT with a Concomitant 84% Reduction in Mutant Z-AAT Following BEAM-302 60 mg Treatment

Post-treatment Inducibility of AAT Observed During Respiratory Infection with a Patient Reaching ~30 µM Total AAT, Retaining 95% M-AAT Composition

Well-tolerated Safety Profile Observed with Single Doses of BEAM-302 up to 75 mg; Safety Consistent Across Single-dose Part A and Part B Cohorts

60 mg Selected as Optimal Biological Dose, Supported by Strong Safety and Efficacy Profile Across Single-dose Cohorts; Global Pivotal Cohort Expected to Initiate in Second Half of 2026

Beam to Host Investor Webcast Today, March 25, 2026, at 8:00 a.m. ET

CAMBRIDGE, Mass., March 25, 2026 (GLOBE NEWSWIRE) -- Beam Therapeutics Inc. (NASDAQ:BEAM), a biotechnology company developing precision genetic medicines through base editing, today announced updated safety and efficacy data from the ongoing Phase 1/2 trial of BEAM-302 and the selection of 60 mg as the optimal biological dose to advance into pivotal development to support potential accelerated approval. BEAM-302 is a liver-targeting lipid-nanoparticle (LNP) formulation designed to directly correct the underlying genetic mutation that causes the severe form of alpha-1 antitrypsin deficiency (AATD) through base editing.