BioMarin is paying $70 million upfront to license a Fabry disease drug candidate, expanding the franchise it acquired through its $4.8 billion takeover of Amicus Therapeutics.
The Amicus acquisition gave BioMarin control of Galafold, an oral Fabry treatment that generated $521.7 million in net product sales in 2025. Now, BioMarin is adding a long-acting enzyme replacement therapy (ERT) in phase 1/2 development through a licensing deal with South Korea's GC Biopharma and Hanmi Pharm.
BioMarin is paying $70 million upfront and committing up to $405 million in development and commercial milestone payments, plus tiered royalties on sales. The agreement gives BioMarin rights to the drug candidate, known as HM15421/GC1134A, worldwide except South Korea, where GC and Hanmi will retain commercialization rights.
The South Korean companies started a phase 1/2 first-in-human study of the drug candidate last year. The trial is enrolling patients with Fabry disease in the U.S., Argentina and South Korea to evaluate the safety, tolerability, pharmacokinetics and efficacy of the ERT. Investigators are testing three dose levels and assessing measures of kidney function and other outcomes over a period of up to 48 weeks.
Two ERTs, Sanofi's Fabrazyme and Chiesi's Elfabrio, have FDA approval, while Takeda's Replagal is approved in many international markets. All three are administered by intravenous infusion every two weeks. GC and Hanmi designed their candidate to be administered by subcutaneous injection once a month, potentially offering patients a more convenient alternative to existing ERTs.
If successful, the new therapy would give BioMarin another way to compete in the Fabry disease market. Galafold is an oral treatment that binds to and stabilizes certain misfolded enzymes, allowing them to reach lysosomes and function properly. Amicus evaluated the therapy in a pivotal study that enrolled patients who had never received ERT or had been off enzyme therapy for at least six months.
BioMarin is targeting peak annual Galafold sales of approximately $1.4 billion by the mid-2030s, with improved diagnosis rates central to its growth strategy. Those efforts could also benefit HM15421/GC1134A by identifying more patients who need treatment. While Galafold is approved only for patients with certain genetic mutations, the experimental ERT could potentially serve a broader Fabry disease population.