Celltrion has agreed to pay as much as ₩1.06 trillion ($735 million) for two preclinical antibody candidates from Maryland biotech Kaigene, marking the South Korean company’s latest effort to diversify beyond its biosimilar business. The deal includes an upfront payment of ₩11.4 billion ($7.9 million), with the remainder tied to development and commercial milestones.
One asset, designated KG006, is described as a next-generation FcRn inhibitor with what Kaigene characterizes as extended durability compared with existing therapies. The second candidate, KG002, aims to both degrade disease-specific autoantibodies and suppress the B cells producing them. Celltrion secured global rights for KG006 excluding China and Japan, and worldwide rights for KG002.
The FcRn inhibitor market has drawn intense competition, with approved drugs from Argenx, Johnson & Johnson, and UCB already treating conditions like myasthenia gravis and chronic inflammatory demyelinating polyneuropathy. Analysts project Argenx’s efgartigimod could reach $8.3 billion in sales by 2033.
Kaigene was founded by Shin Min-jae, who previously led development of the FcRn inhibitor batoclimab at HanAll Biopharma. Celltrion has stated it plans to submit investigational new drug applications for 13 candidates by 2028 as it works to transform from a biosimilar specialist into a novel drug developer. The company reported record 2024 revenue but has been investing heavily in its pipeline and manufacturing capacity.
The substantial price tag for preclinical assets reflects both the potential of autoimmune treatments and the risks inherent in early-stage drug development, where the majority of candidates fail before reaching approval.
