Coultreon Biopharma, a 10 person spinout from Galapagos, has raised $125M to pursue salt inducible kinase (SIK) inhibitors for inflammatory diseases, reprising a target that failed in Galapagos's midphase trials in 2022. A February 2025 JCI Insight paper co authored by Galapagos…
A Belgian biotech that couldn't make its physics work is back for more. This time it's a spinout with 10 employees, $125 million, and the same target that helped sink its parent company.
Galapagos spent years and enormous resources on JAK inhibitors, then cell therapy. Both collapsed. Now the company has spun out its inflammation program to a dedicated team, betting that focus can accomplish what scale couldn't. Coultreon Biopharma closed its Series M round this week Endpoints News. Pierre Raboisson, formerly of the Raboisson family lab, is CEO. The company was founded in January 2025 in Leuven, Belgium and currently employs about 10 people, according to company registry filings. Top-tier US and European biotech investors participated, Endpoints reported.
The target is salt-inducible kinases, or SIKs. These enzymes act like a thermostat on immune cells, dialing inflammation up or down depending on signals in their environment. A peer-reviewed paper co-authored by Galapagos scientists, published in JCI Insight in February, showed that selectively blocking these enzymes reprogrammed inflammatory pathways in mouse models of colitis, psoriasis, and arthritis JCI Insight. Preclinically, the mechanism holds.
Clinically is another story.
Galapagos tried this before. Its lead SIK compound, GLPG3970, went into midphase trials (the stage where you first test whether a drug actually helps patients, not just that it is safe) and failed to beat placebo in 2022. The failure was public and effectively ended the Toledo program. Galapagos moved on to cell therapy. That bet also collapsed. The company is now winding down its cell therapy operations, a process initiated in January 2026 that has affected 365 employees across sites in Europe, the US, and China.
Coultreon is the Toledo program's third act. Same target, new company, fresh capital, dedicated team.
What specifically makes this iteration different is unclear. The Endpoints article is paywalled, and Coultreon has not published its clinical strategy. The JCI Insight paper demonstrates the basic science is sound. But understanding why GLPG3970 failed matters enormously: insufficient target selectivity, wrong patient population, wrong disease indication, or simple bad luck in a difficult-to-treat population are all plausible explanations, and they point to very different solutions. One competitor, Nimbus Therapeutics, has a SIK2 inhibitor advancing toward first-in-human studies for inflammatory and autoimmune diseases, suggesting the mechanism is still taken seriously by serious operators.
The science is legitimate. The track record is not encouraging. A 10-person spinout with $125 million and an old target is either a contrarian bet with real insight, or the kind of deal that gets made when the story sounds better in a fundraising deck than it reads in a clinical chart.
We'll know in a few years. For now, Coultreon is making the same pitch every biotech makes after a failure: this time we understand it better.
We'll see.