Galapagos has spent the better part of a decade trying to figure out what it wants to be.
Filgotinib, the JAK1 inhibitor that was supposed to be its franchise drug, ran into FDA complete response letters and lost most of its commercial promise.
Their fibrosis pipeline has been recut.
Their cell therapy ambitions hit a brick wall.
They’ve laid off staff and re-pitched their strategy more times than is comfortable.
But the science wasn’t the problem.
They had genuinely interesting kinase work going on inside the building.
Well, someone smart noticed.
That “someone” is now Coultreon Biopharma, which just closed a $125 million Series A led by Sofinnova Investments and co-led by Forbion and Novo Holdings. The Leuven-based company spun out of Galapagos with over 15 years of accumulated salt-inducible kinase biology under the hood.
The lead asset is COL-5671, a once-daily oral selective inhibitor of SIK3, currently in Phase 1. Phase 2 trials are planned in psoriasis and ulcerative colitis.
The mechanism is interesting in a way that has been quietly building over the last few years.
SIK3 sits upstream of major inflammatory cytokine production. Inhibiting it reduces TNFα and IL-23, the two cytokines that anti-Humira biosimilars and Skyrizi/Tremfya have been chasing for years. SIK3 inhibition also increases IL-10, which is the regulatory cytokine that keeps inflammation in check.
If COL-5671 can do that pharmacology in a pill, it’s competing with Skyrizi and Stelara on a delivery format those biologics simply cannot match.
So, could be BIG. Only if it works.
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Now, let’s take another look at this syndicate because…ummm…it’s noteworthy.
Sofinnova lead, Forbion and Novo as co-leads, with Galapagos itself rolling equity into the spinout. Then add Regeneron Ventures, Balyasny Asset Management, Luma Group, Samsara BioCapital, Longwood Fund, and Finchley.
That is what a $125M immunology Series A looks like in 2026, with a real syndicate of immunology specialists plus crossover capital plus the parent’s stake. Onco3R/Coultreon was founded in 2025.
They got from incorporation to this round in about a year.
Onco3R-as-Coultreon also signals where the bigger pipeline goes. The press release flags both immunology and oncology indications. The company description mentions oncology candidates beyond COL-5671.
SIK3 has been linked to cancer cell metabolism and tumor immunity through several mechanisms, so the platform’s reach beyond psoriasis and IBD may be substantial.
The hard part for Coultreon will be the same as for every oral immunology asset trying to muscle into the IBD and psoriasis market: the safety profile has to be airtight.
JAK inhibitors have shown how quickly an oral immunology asset can lose its label expansion when serious adverse events show up. SIK3 is a different target with different biology, but the regulatory bar will be similar.
Phase 2 readouts in 2027 will tell.
Until then, this is one of the more thoughtful immunology spinouts of the year, and one of the most patient ones too.
Fifteen years of preclinical work doesn’t usually get this kind of clean Series A debut.
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