Coultreon Biopharma (rebranded from an Onco3R Therapeutics spinout) raised a $125 million Series A to advance COL-5671, an oral SIK3 inhibitor designed for autoimmune indications. The round was led by Sofinnova Investments with Forbion and Novo Holdings as co-leads, alongside multiple long-term investors. COL-5671 is in Phase 1 with plans to begin Phase 2 studies next year with psoriasis and ulcerative colitis targets for clinical proof-of-concept. The company said its mechanism involves SIK3 inhibition to reduce pro-inflammatory cytokines such as TNFα and IL-23 while increasing IL-10. The financing underscores investor appetite for oral, targeted immunology programs that aim to match or improve on injectable biologics while offering potentially broader disease control.