Coultreon Biopharma, a Belgium-based biotechnology company formerly known as Onco3R Therapeutics, has closed an oversubscribed 125 million dollar Series A financing round to advance its immunology pipeline. The round was led by Sofinnova Investments and co-led by Forbion and Novo Holdings, with additional participation from Galapagos, Regeneron Ventures, Balyasny Asset Management, Luma Group, Samsara BioCapital, Longwood Fund, and Finchley Healthcare Ventures.
Proceeds will fund the clinical development of COL-5671, a highly selective, oral once-daily SIK3 inhibitor currently in Phase 1 studies. The company plans to advance the therapy into Phase 2 trials for psoriasis and ulcerative colitis, with potential to demonstrate clinical proof-of-concept in 2027. COL-5671 was initially developed by Galapagos NV and fully transferred to Coultreon in April 2025, when Galapagos also provided an initial seed investment.
Coultreon’s approach is grounded in more than fifteen years of research into salt-inducible kinases, a family of proteins that regulate key inflammatory pathways. By targeting SIK3, COL-5671 reduces transcription of pro-inflammatory cytokines including TNFα and IL-23 while increasing expression of the immunoregulatory cytokine IL-10. The company believes this mechanism has the potential to deliver broader and more durable disease control than existing therapies across multiple immune-mediated conditions including ulcerative colitis, Crohn’s disease, psoriasis, psoriatic arthritis, and rheumatoid arthritis. Coultreon is headquartered in Leuven, Belgium.
KEY QUOTES:
“This financing marks a major inflection point for our company. 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. I am extremely proud of what the team has achieved, and I look forward to advancing our novel first-in-class therapies to patients.”
Pierre Raboisson, CEO, Coultreon Biopharma
“We have strong conviction in the company’s lead SIK3 program to be valuable across a range of auto-immune diseases where patients would benefit from an alternative oral treatment option.”
Maha Katabi, General Partner, Sofinnova Investments
