Japanese drugmaker Shionogi announced it will acquire one of the only approved therapies for amyotrophic lateral sclerosis (ALS) for roughly $2.5 billion, expanding the company’s footprint in rare neuromuscular disease. The transaction transfers ownership of an approved product, giving Shionogi immediate commercial presence and patient access in ALS. Management framed the acquisition as central to Shionogi’s rare‑disease strategy and pipeline diversification. The deal underscores M&A as a rapid route to rare disease franchises with existing reimbursement and market uptake.