Coultreon bags US$125m for autoimmune pipeline

Leuven‑based Coultreon Biopharma, formerly Onco3R Therapeutics, will use the capital to move its lead candidate, the salt‑inducible kinase 3 (SIK3) inhibitor COL‑5671, into Phase II trials. Designed to address core inflammatory pathways across multiple autoimmune diseases, COL‑5671 has already shown a favourable safety and tolerability profile in early clinical cohorts. By targeting SIK3, the therapy reduces transcription of key pro-inflammatory cytokines, including TNFα and IL-23, while increasing expression of the immunoregulatory cytokine IL-10. This differentiated mechanism has the potential to deliver broader and more durable disease control compared to existing therapies. COL-5671 was initially developed by Galapagos NV, and ownership was fully transferred to Coultreon in April 2025, when Galapagos provided an initial seed investment.

Sofinnova Investments led the financing round, with Forbion and Novo Holdings as co-leads, joined by Galapagos, Regeneron Ventures, Balyasny Asset Management, Luma Group, Samsara BioCapital, Longwood Fund and Finchley Healthcare Ventures. The round reflects strong investor interest in alternative immunomodulatory pathways beyond the established TNF, IL‑23 and JAK‑targeting space. “With the support of this top-tier syndicate, we are well positioned to advance our SIK program, while unlocking the broader potential of our pipeline,” said Pierre Raboisson, CEO of Coultreon Biopharma.