BioMarin Pharmaceutical has secured exclusive worldwide rights, excluding South Korea, to an investigational enzyme replacement therapy for Fabry disease from GC Biopharma and Hanmi Pharm. The agreement adds a potential treatment option for the rare genetic disorder as BioMarin expands its presence in the disease area.

The licensed candidate, HM15421/GC1134A, is a long-acting recombinant alpha-galactosidase A enzyme therapy currently being evaluated in a Phase 1/2 clinical trial in people with Fabry disease. The treatment is administered subcutaneously and could become the first enzyme replacement therapy for the condition delivered through an injection under the skin.

Fabry disease is an inherited disorder caused by deficient activity of the alpha-galactosidase A enzyme, leading to the buildup of certain fatty substances in cells. This accumulation can damage multiple organs, including the kidneys, heart, and nervous system. BioMarin said the candidate could potentially reach patients whose genetic mutations are not amenable to treatment with GALAFOLD, a therapy for eligible patients with Fabry disease.

Under the terms of the agreement, BioMarin will pay $70 million upfront. GC Biopharma and Hanmi Pharm are jointly eligible to receive up to an additional $405 million tied to development and commercial milestones, along with tiered royalties on net sales.

Preclinical studies of HM15421/GC1134A showed activity across several measures, including kidney function, vascular health, and peripheral nervous system outcomes. The FDA granted the candidate Orphan Drug Designation in 2024.

BioMarin CEO Alexander Hardy says the agreement builds on the company’s commitment to the Fabry disease community, following its acquisition of Amicus earlier in 2026. He added that the candidate could broaden the company’s treatment portfolio and provide another potential option for patients.

Following completion of the ongoing Phase 1/2 study, BioMarin will take responsibility for subsequent clinical development, manufacturing, and commercialization in markets outside South Korea. GC Biopharma and Hanmi Pharm will retain commercialization rights in South Korea.

The deal expands BioMarin’s clinical pipeline in rare diseases and gives the company an opportunity to advance a potential next-generation enzyme replacement therapy with a different route of administration for people living with Fabry disease. The candidate’s safety and efficacy will need to be established through further clinical evaluation.

To learn more, please visit www.biomarin.com.