Beam reports BEAM-302 raised functional AAT in AATD patients, the first clinical correction of a disease-causing mutation

Beam Therapeutics/BEAM-302 (AATD)

In the first nine patients, a single dose of the in vivo base editor BEAM-302 raised total and functional AAT and lowered the mutant Z-AAT protein. At 60 mg, mean total AAT reached 12.4 µM by day 28, above the 11 µM protective threshold, and Z-AAT fell 78%, with no serious adverse events.

• BEAM-302: in vivo base-editing therapy targeting the SERPINA1 gene in AATD patients.
• 60 mg dose: mean AAT 12.4 µM (above 11 µM protective threshold), Z-AAT reduced 78%.
• No serious adverse events or Grade 3+ transaminase elevations; safety exceptional across doses.
• First human clinical evidence of base-editing-induced disease-gene correction.