Celltrion Licenses KG013 for Up to $580.5 Million to Develop and Commercialize It Globally
Key Facts
Celltrion and Kaigen announced an exclusive global license agreement on October 22, 2026, granting Celltrion rights to develop and commercialize drug candidate KG013, with the deal’s total value reaching up to $580.5 million. The consideration includes an upfront payment and payments tied to the achievement of development, regulatory and commercialization milestones, so the figure does not represent an upfront cash payment. Royalties on net sales are payable separately from this value, according to Kaigen’s announcement published via PR Newswire. Kaigen retained an option to co-commercialize the drug in South Korea. The deal places the candidate within Celltrion’s autoimmune treatment pipeline, which the company said the agreement strengthens through strategic partnerships and expands with a mechanism targeting APRIL protein.
KG013 targets IgA nephropathy, known as IgAN, as its first planned indication. In the disease, immune complexes containing IgA accumulate in the kidneys, causing inflammation and damage, according to Kaigen’s description in its announcement. The company’s chief executive said IgA nephropathy affects about 160,000 diagnosed patients in the United States alone and is particularly common among populations in Asia. He added that about 30,000 patients in South Korea are among those who need effective treatments with a sustained impact. These figures indicate the size of the group targeted by the initial plan, while the agreement did not announce a start date for trials or clinical development.
Kaigen describes KG013 as a fully human, half-life-extended monoclonal antibody that binds to APRIL protein and is being developed for long-acting subcutaneous injections. According to the company, APRIL supports plasma-cell survival and immunoglobulin production. Inhibiting this pathway is intended to suppress the production of pathogenic IgA and IgM antibodies. Kaigen’s pipeline page says the candidate targets autoimmune diseases associated with these two antibody types and aims to suppress autoantibodies without depleting B cells. Kaigen’s chief executive said: "We believe KG013 has the potential to become a leading treatment for IgA- and IgM-related diseases."
The deal extends the licensing relationship between the two companies. On November 4, 2025, Celltrion announced an exclusive agreement with Kaigen covering two candidates to treat autoimmune diseases. Kaigen describes KG013 as the third immune candidate in its dealings with Celltrion, while the new agreement grants Celltrion global development and commercialization rights and gives Kaigen an option to co-commercialize in the South Korean market. The move is part of Celltrion’s expansion from biosimilars into the development of innovative autoimmune drugs, according to the company’s description of its strategy. In its Korean announcement, Celltrion said its next-generation immune drug pipeline had become more robust through strategic open innovation. The announcement does not say KG013 targets tumors; the stated target is autoimmune diseases.
KG013 is being developed as APRIL targeting has become a licensed treatment approach for reducing urine protein in some adults with IgA nephropathy. The U.S. Food and Drug Administration’s accelerated approval of Voyxact was based on an average 50% reduction in urine protein from baseline after 9 months of treatment, compared with a 2% increase with placebo over the same period. The agency said accelerated approval has not yet established that the drug slows long-term decline in kidney function. It tied continued approval to confirmation of clinical benefit in a confirmatory trial. This context puts the development of a new treatment for the disease on a regulatory and clinical path that requires verification of benefit, while neither Kaigen nor Celltrion announced a next milestone for KG013.