Beam Therapeutics Receives FDA RMAT Designation for BEAM-302 Base Editing Therapy for Alpha-1 Antitrypsin Deficiency

CAMBRIDGE, Mass. – May 12, 2025 – Beam Therapeutics Inc. (Nasdaq: BEAM), a company focused on precision genetic medicines through base editing, today announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to BEAM-302. This liver-targeting lipid-nanoparticle (LNP) formulation delivers a guide RNA and an mRNA encoding a base editor designed to correct the genetic mutation responsible for alpha-1 antitrypsin deficiency (AATD).

AATD is an inherited disorder affecting the lungs and/or liver, leading to early-onset emphysema and liver disease. There is a significant unmet need for effective therapies that can address the full spectrum of this disease.

Giuseppe Ciaramella, Ph.D., president of Beam Therapeutics, expressed enthusiasm for the RMAT designation, recognizing BEAM-302’s potential as a transformative, one-time treatment for AATD. He emphasized the strength of their clinical data and the promise of base editing to directly correct the underlying genetic cause of severe AATD. The RMAT designation will allow for closer collaboration with the FDA to potentially accelerate the development of BEAM-302.

The FDA’s RMAT designation supports the development of regenerative medicines, including gene therapies, for serious or life-threatening diseases with unmet medical needs. It offers benefits such as early interactions with the FDA, potential for accelerated approval pathways, and priority review of future biologics license applications.

Positive initial safety and efficacy data from the Phase 1/2 trial of BEAM-302, reported in March, demonstrated clinical proof of concept and in vivo base editing. Preliminary results from the first three dose cohorts showed that BEAM-302 was well tolerated and led to durable, dose-dependent correction of the PiZ mutation and increased total AAT protein levels above the therapeutic threshold in the 60 mg dose cohort. Beam has begun dosing in the fourth cohort (75 mg) and plans to share updated data in the second half of 2025. Additionally, the company anticipates dosing the first patient in Part B of the study, which will include AATD patients with mild to moderate liver disease, in the second half of 2025. The IND for BEAM-302 was cleared by the FDA in March 2025.

About BEAM-302: BEAM-302 is an LNP-formulated base editing therapy designed to correct the PiZ mutation, which is prevalent in severe AATD. This one-time A-to-G correction has the potential to reduce the toxic buildup of misfolded AAT protein in the liver, generate therapeutic levels of corrected AAT protein, and increase total functional AAT in circulation, addressing both liver and lung disease aspects. Correcting the native SERPINA1 gene is also expected to allow for physiological increases in AAT levels in response to inflammation or infection, a key function absent in current protein replacement therapies. The correction is anticipated to be durable based on preclinical and clinical findings.

About Alpha-1 Antitrypsin Deficiency (AATD): AATD is a genetic disorder that can cause early emphysema and liver disease. The PiZZ genotype, resulting from a specific point mutation in both copies of the SERPINA1 gene, represents the most severe form, leading to misfolded AAT protein accumulation in the liver and very low circulating levels. This deficiency leaves the lungs vulnerable to damage and can also cause liver inflammation and cirrhosis. Approximately 100,000 individuals in the U.S. have the PiZZ genotype, with only about 10% diagnosed. Currently, there are no curative treatments, and the approved protein replacement therapy has not been shown to prevent lung function decline.