[Edaily Reporter Kim Seung-kwon ] Celltrion(068270)is acquiring a next-generation drug candidate for autoimmune diseases from a U.S. biotech company.

This move is part of a strategy to expand its business structure—currently centered on biosimilars—to include new drugs, while leveraging its robust overseas distribution network to increase its influence in the global autoimmune disease market.

Celltrion announced on the 22nd that it has signed a global license-in agreement with Kaijin, a biotech company based in Maryland, U.S., for the autoimmune disease drug candidate “KG013.”

Through this agreement, Celltrion has secured exclusive worldwide rights to develop and commercialize KG013. The total value of the agreement, including an upfront payment and milestone payments tied to development, regulatory approval, and commercialization, amounts to up to $580.5 million (approximately 769.5 billion won).

Following commercialization, Celltrion will pay separate running royalties based on net sales, and Kaijin retains the right to participate in co-marketing exclusively in the South Korean market.

Kaijin, the partner company, is a biotech firm specializing in the development of novel multi-antibody drugs based on “PDEG,” its proprietary platform technology that degrades pathogenic autoantibodies.

KG013 is a next-generation antibody drug candidate that targets “APRIL (A Proliferation-Inducing Ligand),” a signaling protein involved in the survival and functional maintenance of antibody-producing B cells. Its primary indications include chronic diseases such as IgA nephropathy (IgAN), which require long-term treatment and ensure safety.

Unlike existing approaches that broadly suppress immune cells or lower blood pressure, it employs a mechanism that selectively inhibits the production of pathogenic IgA, the core cause of the disease. KG013 is designed to significantly improve efficacy and duration of action compared to first-generation therapies, enabling disease control with lower doses and longer dosing intervals. Celltrion aims to develop it into a best-in-class drug.

With this agreement, Celltrion has completed its lineup of three new drugs for autoimmune diseases, adding the anti-APRIL antibody to the two drugs—including the fetal Fc receptor (FcRn) inhibitor—acquired from Kaijin last year.

“KG006,” which targets the immunoglobulin G (IgG) degradation pathway, and “KG013,” which inhibits IgA and IgM production, complement each other, enabling a dramatic expansion of the therapeutic scope.

Celltrion plans to combine the sales infrastructure and commercialization capabilities of its biosimilar product portfolio—which includes tumor necrosis factor alpha (TNF-α) and interleukin (IL) inhibitors that have established a strong presence in the global market—with its new drug lineup.

The company has identified anticancer drugs, obesity and metabolic diseases, and autoimmune diseases as the three pillars of its new drug development and is accelerating a two-track strategy combining in-house development and open innovation.

A Celltrion spokesperson stated, “Following the introduction of an FcRn inhibitor last year, securing the license for this anti-APRIL antibody has further strengthened our open innovation pipeline,” adding, “We will maximize synergies with our existing flagship product lines to maintain our unrivaled leadership in the global autoimmune disease market.”