Quick Facts
- BIOX-101 was well tolerated when added to standard care in patients with acute spontaneous ICH. No major safety concerns were reported, and the treatment produced rapid, reversible target engagement.
- BIOX-101 showed signals of reduced secondary brain injury. Normalized hematoma expansion and perihematomal edema growth were lower with BIOX-101 than with standard care alone.
- The treatment appeared to suppress early inflammation. Neutrophil-to-lymphocyte ratios remained stable with BIOX-101 but increased early in the standard-care group.
- Functional outcomes favored BIOX-101, with a favorable shift in modified Rankin Scale scores. The findings support further evaluation in a larger, later-phase trial.
Structuring the BIRCH Trial
BIRCH was a phase 2a, open-label, randomized proof-of-concept study evaluating the safety, tolerability, and efficacy of BIOX-101 in acute ICH. Patients were eligible for enrollment if they were ≥18 years old and had experienced a first-ever, spontaneous, supratentorial ICH in the cerebral cortex or deep brain structures with a volume ≥5 mL and ≤60 mL, among other criteria. Patients with a history of personal or familial bleeding disorders, as well as a known deficiency in factor XII or hemophilia type A, B, or C, among other criteria, were excluded.2,3
Patients were randomly assigned in a 3:1 ratio to receive either BIOX-101 on top of SoC or SoC alone. The primary endpoints included the incidence of abnormalities in physical examinations, change in HR and PR interval, and change in blood pressure and heart rate 7 days after randomization. Secondary endpoints included change in perihematomal oedema (PHO) and hemorrhage volumes 10 days after randomization and measurement of the effects of BIOX-101 on the activated Partial Thromboplastin Time (aPTT) and factor XI and XII inhibition.3
A total of 17 patients were assigned to receive BIOX-101, and 6 received only SoC treatment. BIOX-101 was administered as a 48-hour infusion. Hemelsoet and colleagues assessed PK/PD and neutrophil-to-lymphocyte ratio (NLR) ≤168 hours, while safety and functional outcomes, determined by modified Rankin Scale (mRS) scores, were assessed ≤day 360.1
Outcomes of BIOX-101 Treatment
Hemelsoet and colleagues noted that BIOX-101 achieved active plasma levels within <1 hour, with stable exposure and rapid and reversible pharmacodynamic effects. The aPTT ratio at this timepoint was roughly 2.5. The BIOX-101 cohort also saw greater baseline hematoma and perihematomal edema volumes compared to those receiving only SoC; however, after normalizing to baseline volumes, hematoma expansion and perihematomal edema growth were reduced compared with the SoC arm.1
By Day 7, DW-MRI showed a low incidence of ischemic lesions or microhemorrhages with BIOX-101, and NLR remained low and stable in the treatment arm while increasing early with only SoC. A favorable shift in mRS was also noted in the BIOX-101 arm.1
“BIOX-101 is safe, demonstrated rapid target engagement and showed encouraging signals of reduced secondary injury and improved recovery,” Hemelsoet and colleagues wrote. “These findings support advancement to a late-phase trial.”1
References
Hemelsoet D. BIRCH: A Phase IIa Randomized Study of BIOX-101 in Acute Intracerebral Hemorrhage. Presented at the World Stroke Congress (WSC) 2026, Seoul, Republic of South Korea. October 21-23, 2026.
Bioxodes S.A. A Study to Evaluate the Safety, Tolerability and the Effects of Ixodes Ricinus-Contact Phase Inhibitor (Ir-CPI) in Adult Patients With Spontaneous Intracerebral Hemorrhage (BIRCH). ClinicalTrials.gov Identifier: NCT05970224. Updated July 23, 2026. Accessed October 21, 2026. https://clinicaltrials.gov/study/NCT05970224?term=NCT05970224&rank=1