Beam presents updated BEAM-302 Phase 1/2 data as a late-breaker at ERS Congress 2026

Beam Therapeutics/BEAM-302 (AATD)

Beam's BEAM-302, a one-time base-editing infusion that rewrites the single DNA letter behind alpha-1 antitrypsin deficiency (AATD), kept protective protein levels in the blood for up to 18 months of follow-up. At the chosen 60 mg dose, mean total AAT stayed above the 11 µM level thought to protect the lungs, and almost all the AAT now made was the corrected, normal form. Beam is using 60 mg in a pivotal cohort aimed at US accelerated approval.

• Why it matters: AATD's faulty Z protein fails to protect the lungs and builds up in the liver; correcting the gene can address both.
• 29 evaluable patients. At 60 mg, mean total AAT was 14.4 µM in Part A and 13.5 µM in Part B, up from about 5 µM at baseline.
• Circulating mutant Z-AAT fell 84%, and 93% of AAT was the corrected M form, above the ~80% seen in healthy MZ carriers.
• Infusion reactions in 41% of patients; mostly Grade 1 liver-enzyme rises, plus one transient Grade 3 rise that needed no treatment.
• About 50 more patients will be enrolled; the planned approval endpoint is AAT biomarkers over 12 months. First pivotal patient was dosed in July.