Post Hoc Analysis of Recombinant C1 Inhibitor Clinical Data Using Contemporary Endpoints for Hereditary Angioedema.

Publication Title

Advances in therapy

Document Type

Article

Publication Date

5-20-2026

Keywords

california; santa monica; psjhc

Abstract

Introduction: Contemporary trials of medications to treat hereditary angioedema (HAE) attacks define efficacy endpoints using Patient Global Impression of Severity (PGI-S) and Patient Global Impression of Change (PGI-C) scales; these differ from the visual analog scale (VAS) and treatment effect questionnaire (TEQ) used in legacy recombinant human C1 esterase inhibitor (rhC1-INH) studies. This post hoc analysis aimed to evaluate pooled rhC1-INH trial data, mapped to contemporary HAE clinical trial endpoints and designs.

Methods: Pooling data from three rhC1-INH trials for acute HAE attacks (NCT00225147, NCT01188564, NCT00262301), this analysis applied results from a bookmarking study to convert TEQ and VAS measurements to PGI-S and PGI-C scales. Kaplan-Meier estimates were calculated for time to complete resolution (TTCR; defined as "none" on PGI-S) and time to onset of symptom relief (TOSR; defined as "a little better" on PGI-C at ≥ 2 consecutive time points within 12 h). Log-rank tests were used to determine differences between treatment groups.

Results: Across trials, 48 and 60 patients received rhC1-INH 50 U/kg and placebo, respectively. The most common attack locations were peripheral (47.9% and 41.7%, respectively) and abdominal (35.4% and 35.0%, respectively). Baseline attack severity was either severe or very severe in all patients. Median [95% confidence interval (CI)] TOSR was 0.75 h (0.55-1.50) with rhC1-INH and 8.00 h (3.00-8.05) with placebo (P < 0.001). Median (95% CI) TTCR was 4.50 h (3.55-5.50) with rhC1-INH and 24.00 h (16.00- > 24.00) with placebo (P < 0.001).

Conclusion: This post hoc analysis confirmed that rhC1-INH, compared with placebo, is associated with significantly shorter TOSR and TTCR of HAE attacks.

Clinical trial registration: ClinicalTrials.gov: NCT00225147, NCT01188564, NCT00262301.

Specialty/Research Institute

Allergy & Immunology

Specialty/Research Institute

Dermatology

Specialty/Research Institute

Internal Medicine

DOI

10.1007/s12325-026-03625-0

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