The $70 million license gives BioMarin development and sales rights outside South Korea for a Fabry disease candidate still in Phase 1/2 testing, an early step toward possible commercialization.
GC Biopharma and Hanmi Pharm are jointly eligible for as much as $405 million in payments linked to development and sales milestones. The cap applies to both companies together. The contract also provides tiered royalties based on net sales, but BioMarin did not state the royalty rates or when milestones would be paid.
After the current Phase 1/2 trial, BioMarin will be solely responsible for further clinical work, manufacturing and sales outside Korea. GC Biopharma and Hanmi will retain commercialization rights in South Korea.
HM15421/GC1134A is a human recombinant alpha-galactosidase A enzyme replacement therapy being tested in people with Fabry disease. BioMarin says the candidate was designed to keep the enzyme active longer and improve its stability compared with existing enzyme replacement treatments, with the aim of enabling injections under the skin. BioMarin’s announcement reported preclinical findings covering kidney, vascular and peripheral nerve measures, but no clinical outcome data.
Fabry disease is an inherited disorder associated with changes in the GLA gene. BioMarin says reduced alpha-galactosidase A activity can lead to a buildup of GL-3. Hanmi’s 2024 announcement described the candidate’s intended schedule as an under-the-skin injection once a month. It said existing enzyme replacement treatments are generally given through intravenous infusions every two weeks.
BioMarin completed its acquisition of Amicus Therapeutics on April 27, 2026, adding GALAFOLD (migalastat) to its portfolio. A BioMarin filing describes GALAFOLD as the first oral treatment for Fabry disease. BioMarin CEO Alexander Hardy said HM15421/GC1134A could potentially serve patients with mutations for which GALAFOLD is not suitable. The company frames the license as adding a second potential treatment for Fabry disease.
BioMarin said the candidate received U.S. Food and Drug Administration Orphan Drug Designation in 2024; that designation is separate from marketing approval. ClinicalTrials.gov estimates the study will enroll 18 people and reach primary completion on Aug. 30, 2028.
