Bioxodes BIOX-101 cuts perihematomal oedema growth in Phase 2a ICH trial
Bioxodes has presented full Phase 2a data from its BIRCH trial of BIOX-101 in intracerebral haemorrhage, reporting statistically significant reductions in both haematoma expansion and perihematomal oedema (PHE) growth at 72 hours compared with standard of care. The data were disclosed for the first time as a late-breaking oral presentation at the 18th World Stroke Congress in Seoul on 21 October 2026.
The Belgian clinical-stage company enrolled 23 patients with spontaneous ICH across eight Belgian stroke units in a randomised, open-label design (17 receiving BIOX-101 added to standard of care, six receiving standard of care alone). In baseline-adjusted exploratory analyses, normalised haematoma volume remained essentially flat in the BIOX-101 arm at 72 hours, falling 1.9% from baseline, while it rose 25.5% in the control arm (least-squares mean difference: -27.4%; p=0.0097). PHE growth was 49.7% in the BIOX-101 arm versus 128.8% in the control arm (least-squares mean difference: -79.1%; p=0.0098).
Clinical significance and safety
PHE is brain swelling that develops around the bleed. A 2026 meta-analysis of individual participant data, published in Stroke, found that greater PHE growth within 24 to 72 hours of ICH onset was independently associated with death or dependence at 90 days, making early PHE control a clinically meaningful target. BIOX-101 also produced a trend toward lower disability on the modified Rankin Scale that was visible from Day 7 and persisted through Day 360, despite the BIOX-101 group entering the trial with larger baseline bleeds (mean 25.3 mL versus 14.1 mL).
Safety was the primary objective of BIRCH, and the results were clean. There were no deaths, no treatment-related serious or severe adverse events, and no secondary haemorrhages on Day 7 MRI in either group. The most frequent treatment-related event was prolonged aPTT, consistent with the dual mechanism of BIOX-101, which inhibits coagulation factors XI and XII. Target engagement was confirmed: mean factor XI and factor XII inhibition of 62% and 81%, respectively, was maintained across the 48-hour infusion window.
Dr Dimitri Hemelsoet of Ghent University Hospital, presenting author, said the results were "very encouraging exploratory findings from such a small open-label study," noting that consistency across imaging, biomarker and functional endpoints supports proceeding to a larger blinded trial.
Competitive landscape and next steps
ICH accounts for roughly 10 to 15% of all strokes globally but carries disproportionately high mortality, and no pharmacological treatment is currently approved for the condition. That regulatory vacuum has attracted a handful of academic and commercial programmes over the past decade, including approaches targeting haematoma expansion with haemostatic agents, but none has yet translated Phase 2 signal into a licensed therapy. BIOX-101's dual inhibition of factors XI and XII positions it as an anti-thromboinflammatory candidate rather than a pure haemostatic agent, distinguishing it mechanistically from prior attempts.
Bioxodes is now preparing BIRCH 2, a randomised, double-blind, placebo-controlled Phase 2b trial planned to enrol approximately 230 patients globally. The primary endpoint will be PHE volume at 72 hours adjusted for baseline; functional outcome on the mRS at Day 90 and Day 180, and all-cause mortality, are planned as secondary endpoints. The independent Data Monitoring Committee recommended retaining the same patient criteria and dosing regimen used in BIRCH. The company said it is in discussions with potential partners and investors to finance the study, and plans to host a key opinion leader event and investor webcast following the congress presentation. A successful BIRCH 2 readout would likely be required before any regulatory submission, meaning approval remains several years away even under an optimistic timeline.