Beam Therapeutics gains 5% as FDA clears BEAM-304 IND for PKU

Beam Therapeutics received US Food and Drug Administration clearance to begin a Phase I/II trial of BEAM-304 in patients with phenylketonuria, advancing its liver-targeted base editing platform into a second clinical indication. Shares of the Cambridge, Massachusetts-based company rose 5% on the news.

PKU is an inherited metabolic disorder affecting roughly one in 10,000 to 15,000 newborns in the US, caused by mutations in the PAH gene that lead to toxic accumulation of phenylalanine. Current standard of care involves a strict lifelong low-protein diet and medical foods, with limited pharmacologic options such as BioMarin Pharmaceutical's Kuvan (sapropterin), which is effective only in a subset of patients with residual enzyme activity. BEAM-304 uses adenine base editing to correct the underlying genetic mutation directly in liver cells, offering a potential one-time treatment.

The FDA nod follows Beam's presentation of updated Phase 1/2 data for BEAM-302 in alpha-1 antitrypsin deficiency at the American Thoracic Society International Conference on May 18. Chief Medical Officer Amy Simon said at the time that the findings supported treating AATD "at the root cause of disease" using a one-time gene-editing therapy, and the company plans to start a pivotal cohort in the second half of 2026. Trial investigator John Hurst called the approach "a paradigm shift" after results showed a single dose could restore AAT function.

Beam's platform uses CRISPR-based base editors that make single-letter DNA changes without creating double-strand breaks, a technology the company is applying across multiple liver disorders. The PKU program enters a competitive landscape that includes gene therapy approaches from other developers, though no approved genetic medicine currently exists for the condition. The global PKU treatment market was valued at roughly $1.2 billion in 2025, driven largely by dietary management products.

Beam held approximately $1.1 billion in cash as of its most recent quarterly filing, providing runway through multiple clinical readouts. The company's ability to advance two liver-targeted programs into the clinic within a single year strengthens its position in the genetic medicine space, where investors are watching for proof-of-concept data that could validate base editing as a therapeutic modality beyond sickle cell disease. Intellia Therapeutics, which is developing a CRISPR-based therapy for transthyretin amyloidosis, represents a key peer in the liver-targeted gene editing space.

This article is for informational purposes only and does not constitute investment advice.