Rockville, Maryland-based Kaigene has entered another major international licensing agreement with South Korea’s Celltrion, giving the drugmaker exclusive worldwide development and commercialization rights to KG013, an experimental antibody therapy initially aimed at IgA nephropathy, a chronic kidney disease. The agreement could bring Kaigene up to $580.5 million in upfront and milestone payments, plus royalties on future sales, extending a partnership that began with two other autoimmune drug candidates last year. Kaigene’s announcement and Celltrion’s announcement confirm the transaction.
A New Agreement Builds on an Existing Partnership
Celltrion will lead KG013’s global development and commercialization, while Kaigene retains an option to participate in co-marketing in South Korea. The headline value is a potential maximum, not an upfront cash payment: most of the consideration depends on future development, regulatory and commercial milestones. The upfront amount was not disclosed, and royalties would be paid separately if the product reaches the market.
Targeting an Immune Pathway in Kidney Disease
KG013 targets APRIL, a protein involved in the survival of antibody-producing cells and the production of immunoglobulins. Kaigene is developing the fully human antibody to reduce harmful IgA and IgM antibody activity, beginning with IgA nephropathy, a disease in which IgA-containing immune deposits damage the kidneys. The candidate is designed for long-acting subcutaneous administration, potentially allowing less frequent dosing. Those advantages remain development goals rather than demonstrated patient outcomes. Kaigene’s pipeline listing places KG013 at the IND-enabling stage, before human clinical testing.
Third Candidate Deepens the Companies’ Relationship
The agreement follows a November 2025 licensing deal covering KG006, an FcRn inhibitor, and KG002, a dual-acting antibody candidate. That earlier agreement provided $8 million upfront and up to $736 million in potential milestone payments, plus royalties. In July 2026, Kaigene also licensed Japanese rights to KG006 to Taisho Pharmaceutical, further extending its international development network. For Celltrion, the new APRIL-targeting asset adds a different mechanism to its growing innovative-drug portfolio as it expands beyond its established biosimilars business.
