Hematology · 2 h ago
Eculizumab response patterns in high-risk transplant-associated TMA
This study compared 85 children and young adults with high-risk transplant-associated thrombotic microangiopathy (TA-TMA) treated with pharmacokinetic/pharmacodynamic-guided eculizumab. Non-responders had more severe organ injury and poorer survival, with evidence of persistent endothelial injury despite sustained suppression of terminal complement activity.
- Non-responders had more severe organ injury and poorer survival.
- Durable sC5b-9 normalization took a median of 35 days.
- Endothelial injury markers remained elevated despite complement suppression.
- Interferon signaling may contribute to treatment resistance.
Researchers compared 55 responders and 30 non-responders among 85 children and young adults with high-risk TA-TMA who received pharmacokinetic/pharmacodynamic-guided eculizumab. The analysis examined treatment response, complement activity, markers of endothelial stress and interferon signaling, and survival.
Non-responders had more severe systemic organ injury and markedly inferior survival. They required intensified eculizumab dosing to suppress terminal complement activity, measured by sC5b-9. Durable sC5b-9 normalization took a median of 35 days (IQR 21.5–55). Despite sustained suppression, non-responders had persistently elevated proteinuria and endothelial-stress and interferon-signaling markers, including ST2 and CXCL9. In a subset receiving eculizumab plus the interferon-γ blocker emapalumab, complement pharmacodynamics improved despite greater baseline complement activation.
The findings suggest persistent endothelial injury may contribute to non-response beyond circulating terminal complement activity, and support further study of interferon signaling in treatment resistance. The source reports an observational response comparison, not evidence that adding emapalumab improves clinical outcomes. The study population was limited to children and young adults, and the supplied abstract does not provide further details on design limitations or the combination-treatment subgroup.
In practice
For children and young adults with high-risk TA-TMA receiving eculizumab, non-response was associated with more severe organ injury, poorer survival, and persistent proteinuria and endothelial-stress markers despite sustained sC5b-9 suppression. Durable sC5b-9 normalization took a median of 35 days, underscoring that early complement suppression may not reflect resolution of endothelial injury. These findings do not establish a management change: the reported emapalumab combination observation is a subset finding, and the source does not show that it improves clinical outcomes.
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Blood Advances: Patterns of Response to Eculizumab in High-Risk Transplant-Associated Thrombotic Microangiopathy ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.