Capricor Sues Nippon Shinyaku Over 'Fatal Flaw' in Duchenne Drug Pricing Deal

Capricor Therapeutics has launched a legal assault against Nippon Shinyaku, accusing the Japanese pharmaceutical company and its U.S. subsidiary of deliberately stalling on marketing commitments for a Duchenne muscular dystrophy treatment while refusing to fix a pricing formula that the biotech calls a "fatal flaw" in their exclusive distribution agreement. The lawsuit, filed Thursday in New Jersey state court, alleges that the pricing structure would make it "economically impracticable" for the therapy, deramiocel, to reach patients covered by Medicare, Medicaid, and private insurers.

At the heart of the dispute is a reimbursement mechanism that ties Medicare payments to the price Capricor charges NS Pharma, which serves as the sole U.S. buyer under the agreement. According to the complaint, healthcare providers would receive less in reimbursement than they would spend to acquire and administer the drug—a structural defect that Nippon Shinyaku and NS Pharma disclosed in March 2025 but have allegedly refused to correct. Capricor claims its partner has also failed to execute on marketing plans for deramiocel, raising questions about the Japanese company's commitment to the partnership.

The confrontation threatens to derail patient access to a treatment for Duchenne muscular dystrophy, a devastating genetic disorder that primarily affects boys and leads to progressive muscle degeneration. The case highlights the complex financial engineering that underpins rare disease drug distribution in the United States, where pricing formulas must navigate Medicare reimbursement structures, specialty pharmacy networks, and exclusive licensing arrangements. For Capricor, the stakes are significant: a drug without viable commercial distribution cannot reach the patients it was designed to serve.