Shares of Beam Therapeutics Inc. (NASDAQ:BEAM) gained about 8% on Wednesday after the company released updated results from its ongoing Phase 1/2 clinical study of BEAM-302, a treatment being developed for alpha-1 antitrypsin deficiency (AATD).
According to the company, patients receiving a 60 mg dose of BEAM-302 achieved a mean steady-state total AAT level of 16.1 µM. All treated patients maintained levels consistently above the protective threshold of 11 µM, with follow-up data extending up to 12 months. Corrected M-AAT represented 94% of total AAT, while levels of the mutant Z-AAT protein were reduced by 84% following treatment with the 60 mg dose.
BEAM-302 is a liver-targeted lipid nanoparticle therapy designed to correct the genetic mutation responsible for the severe form of AATD using base editing technology. The treatment is currently being studied in a Phase 1/2 open-label trial assessing its safety, tolerability, pharmacokinetics, pharmacodynamics, and overall effectiveness.
As of the February 10 data cutoff, a total of 29 patients had received BEAM-302, with follow-up periods reaching up to 18 months. Among 26 patients treated with a single dose, the therapy demonstrated a favorable safety profile at doses up to 75 mg. Reported adverse events were generally mild to moderate, with no serious adverse events or dose-limiting toxicities recorded by the cutoff date.
Based on the observed safety and efficacy across the single-dose cohorts, the company selected 60 mg as the optimal biological dose. Beam said it plans to launch a global pivotal cohort in the second half of 2026 to support a potential accelerated regulatory approval.
Researchers also observed a dynamic increase in AAT expression in one patient in the 60 mg cohort during a respiratory infection. In that case, total AAT levels rose from a steady-state level of 15.9 µM to 29.5 µM, while the AAT composition remained stable at 95% M-AAT.
In Part B of the trial, which includes patients with AATD-related liver disease, single doses of 30 mg and 60 mg of BEAM-302 produced efficacy results consistent with those seen in Part A participants who did not have liver disease.