Beam Therapeutics Presents Additional Data for BEAM-302 in Alpha-1 Antitrypsin Deficiency (AATD) at 2025 Alpha-1 Foundation 7th Global Research Conference and 10th Patient Congress

New Data Demonstrate Proportion of Corrected M-AAT Reached a Mean of 91% of Total AAT in Circulation at Day 28 Following BEAM-302 Treatment in 60 mg Cohort (n=3)

Mean Decrease of 79% in Mutant Z-AAT Observed at Day 28 in 60 mg Cohort (n=3)

Fourth Cohort Evaluating 75 mg of BEAM-302 Initiated, with Updated Data from Part A of the Phase 1/2 Trial Expected to be Presented at a Medical Conference in Second Half of 2025

CAMBRIDGE, Mass., April 05, 2025 (GLOBE NEWSWIRE) --  Beam Therapeutics Inc. (Nasdaq: BEAM), a biotechnology company developing precision genetic medicines through base editing, today presented additional data from the Phase 1/2 clinical trial of BEAM-302 in patients with alpha-1 antitrypsin deficiency (AATD) at the 2025 Alpha-1 Foundation 7th Global Research Conference and 10th Patient Congress, taking place April 4-5, 2025, in Lisbon, Portugal.

Positive initial safety and efficacy data from the Phase 1/2 trial of BEAM-302 were previously reported in March 2025, establishing clinical proof of concept as a potential treatment for AATD and in vivo base editing. Preliminary results from the first three single-ascending dose cohorts demonstrated that BEAM-302 was well tolerated, with single doses of BEAM-302 leading to durable dose-dependent correction of the disease-causing mutation and total AAT protein levels above the therapeutic threshold in the 60 mg dose cohort.

These previously reported data were included in today’s presentation, alongside updated biomarker data from the 60 mg cohort showing levels of corrected protein (M-AAT) and the mutant form of alpha-1 antitrypsin protein (Z-AAT) out to Day 28 for all three patients. At Day 28, the proportion of corrected M-AAT reached a mean of 91% of total AAT in circulation, surpassing levels observed in patients with the MZ genotype where circulating M-AAT is typically ~80%. In addition, treatment with BEAM-302 led to a mean decrease of 79% of circulating mutant Z-AAT from baseline as of Day 28.

“Patients living with AATD can face serious complications, including early onset emphysema and liver disease, and there is a significant unmet need for more effective therapies that can treat the entire spectrum of disease manifestations,” said Amy Simon, M.D., chief medical officer of Beam. “The totality of the data shared to date highlight the promising impact of our approach across multiple drivers of disease pathology, including dose-dependent correction of the disease-causing mutation, rapid elevation in the circulation of total AAT and corrected M-AAT that is functional, and significant reduction in circulating mutant Z-AAT. We are honored to share these findings with the AATD community and look forward to continuing to advance our Phase 1/2 study to bring this potentially transformative treatment to patients as quickly as possible.”