The BioMarin Fabry deal gives the US company exclusive worldwide rights, outside Korea, to an early-stage injectable enzyme therapy. BioMarin announced the licence on 29 October 2026 with GC Biopharma and Hanmi Pharm. The candidate is HM15421/GC1134A, also known as LA-GLA. It is in a Phase 1/2 trial, and the release reports preclinical findings only. BioMarin will pay $70 million upfront, with up to $405 million more dependent on milestones.
BioMarin says it has entered into the agreement. As at 2 November 2026, the release states no closing conditions or expected closing date. No financial or legal advisers are named in the release.
What does the BioMarin Fabry deal pay?
The upfront, milestones and royalties
BioMarin’s release sets out three payment components. The first is a $70 million upfront payment. The second is up to $405 million in development and commercial milestones. The third is tiered royalties on net sales. The release does not disclose the royalty rates or the milestone schedule.
The first two components add up to a maximum of $475 million. That figure is a ceiling, not the price paid. Only the $70 million is an upfront commitment. The remainder depends on events that may never occur. A separate biotech deal structure explainer sets out how upfronts, milestones and royalties differ.
The release says GC and Hanmi are jointly eligible for the milestones. BioSpectator, a Korean trade outlet, reported an equal split. It gave $35 million upfront to each company and up to $202.5 million each in milestones. That split does not appear in BioMarin’s release.
Deal terms at a glance
| Licensee | BioMarin Pharmaceutical |
| Licensors | GC Biopharma and Hanmi Pharm |
| Asset | HM15421/GC1134A (LA-GLA), Phase 1/2 |
| Upfront | $70 million |
| Milestones | Up to $405 million, development and commercial |
| Royalties | Tiered on net sales, rates not disclosed |
| Maximum before royalties | $475 million (sum of the two components above) |
| BioMarin territory | Worldwide, excluding Korea |
| Retained by GC and Hanmi | Commercialisation rights in Korea |
| Expected close | None stated in the release |
| Status | Agreement entered into, announced 29 October 2026 |
Who holds what after the deal
BioMarin receives exclusive worldwide rights, excluding Korea. GC and Hanmi keep commercialisation rights in Korea. The handover comes after the ongoing Phase 1/2 study. At that point, “BioMarin will assume sole responsibility for all subsequent clinical development, manufacturing and commercialization” outside Korea.
The BioMarin Fabry deal is a licence, not an acquisition, so neither Korean company has been bought. The release does not say who funds the current study. A trial listing names GC Biopharma as sponsor.
What is HM15421/GC1134A and what stage is it at?
The candidate is a human recombinant alpha-galactosidase A enzyme therapy, according to the release. Fabry disease is a lysosomal storage disorder caused by inherited changes in the GLA gene. Korea Herald reports that the asset combines Hanmi’s long-acting platform with GC Biopharma’s enzyme replacement experience. That experience includes Hunterase, its Hunter syndrome treatment.
BioMarin says the candidate “has the potential to be the first subcutaneous enzyme replacement therapy for Fabry disease”. That is a company claim about an unapproved product. The FDA granted Orphan Drug Designation in 2024, which does not establish efficacy.
The release gives no dosing interval. Daily Pharm reported in 2024 that the developers designed the therapy for monthly injection. Seoul Shinmun notes that actual dosing intervals still need confirmation in clinical trials.
What the Phase 1/2 trial is testing
The study is NCT06858397, described in a mirrored registry listing as an open-label, dose-range, proof-of-concept study. The listing expects 18 participants. It gives a May 2025 start and an estimated August 2028 completion. It names two US sites, in Los Angeles and Kansas City, and was last updated in November 2025.
BioPharm International reports three dose cohorts and a safety primary endpoint measured over 48 weeks. Participants must be treatment naive or off Fabry therapy for six months, according to the listing. The listing therefore does not describe switching people directly from current infusions.
BioMarin says preclinical studies showed “differentiated efficacy across key measures”. It names renal function, vascular health and peripheral nervous system outcomes. The release gives no figures, and preclinical findings may not predict results in patients.
Why does BioMarin say it wants the asset?
The rationale for the BioMarin Fabry deal is the company’s own. Its headline calls the candidate “a second potential treatment for Fabry disease”. Alexander Hardy is BioMarin’s President and Chief Executive Officer. He said the agreement “reflects our growing commitment to the Fabry community”. He said it builds on the Amicus acquisition. BioMarin completed its Amicus purchase on 27 April 2026. It paid $14.50 per share in cash, about $4.8 billion in total equity value.
Hardy also said the therapy “could allow us to reach a new generation of patients with Fabry”. He specified patients “beyond those with mutations amenable to treatment with GALAFOLD”.
That limit is visible in the label. The Galafold UK SmPC restricts the oral drug to patients with an amenable mutation. BioMarin reported $106 million of Galafold net product revenue for the second quarter of 2026. The release does not estimate how many patients sit outside that group.
The Korean partners framed the BioMarin Fabry deal as an outcome of their collaboration. Korea Herald quoted Lim Ju-hyun, Vice Chair of Hanmi Group: “Through this partnership, we will further accelerate the global development of LA-GLA.” Huh Eun-chul, Chief Executive Officer of GC Biopharma, also credited close research cooperation, the same report said.
How does it compare with current Fabry treatments?
No comparative patient data exist in the release, so only the routes and schedules can be compared. UK labels show that existing enzyme therapies are given by intravenous infusion. Fabrazyme is 1 mg/kg once every two weeks. Replagal is 0.2 mg/kg once every two weeks.
The Elfabrio UK SmPC, revised in May 2026, gives 1 mg/kg once every two weeks. It also allows 2 mg/kg once every four weeks in patients stable on enzyme therapy. Galafold is the oral alternative, at 123 mg once every other day. A subcutaneous product would differ on route, but its clinical standing is unknown.
How does it fit the wider Fabry deal landscape?
The BioMarin Fabry deal is one of several recent transactions in this disease. PTC Therapeutics bought the gene therapy ST-920 from Sangamo in the third quarter of 2026. PTC’s results release gives $111 million upfront and up to $100 million in contingent payments. PTC expects to complete its FDA submission in the fourth quarter of 2026.
Idorsia and Nxera Pharma announced a lucerastat agreement on 28 October 2026. Idorsia said Nxera will pay a CHF 7 million upfront fee. Nxera gains exclusive rights in Japan and selected Asia Pacific territories, excluding China. The oral candidate has entered a pivotal Phase 3 study.
Not every Fabry programme has advanced cleanly. Sanofi said in February 2026 that venglustat missed the primary endpoint in the PERIDOT phase 3 study. Its second study, CARAT, was still ongoing at that date. Larger company takeovers appear in this tracker of billion-dollar biotech acquisitions.
When will the BioMarin Fabry deal produce answers?
The release sets no timetable for later trials, filings or launch. It therefore cannot say when a patient might receive the therapy outside a study. Several events would narrow the uncertainty:
First, BioMarin held its third quarter results call on 2 November 2026. Any management comment there on the licence would add to the release.
Second, first human data would test the preclinical claims. No presentation date has been disclosed. The August 2028 date in the listing is an estimate for study completion, not BioMarin guidance.
Third, milestone payments would show whether development has progressed, if BioMarin discloses them. The schedule is not public, so a reader cannot yet map them to events.
Finally, PTC’s FDA submission for ST-920 will show how quickly a one-time gene therapy could reach the market. The release describes no UK or European filing for HM15421/GC1134A. Any such plan remains unstated as at 2 November 2026.
