Icatibant

Evidence Level: L5

Predicted Indications: 10

Icatibant
Icatibant: From Undocumented Original Indication to C1 Inhibitor Deficiency (Hereditary Angioedema)

## Pharmacist Assessment Report

Icatibant: From Undocumented Original Indication to C1 Inhibitor Deficiency (Hereditary Angioedema)

One-Sentence Summary

Icatibant’s original approved indication is not available in the structured regulatory data provided (drug is currently Not marketed/not marketed in this jurisdiction, 0 licenses on file). The TxGNN model predicts it may be effective for C1 Inhibitor Deficiency, with 23 clinical trials and 20 publications currently supporting this direction — though this evidence largely describes Icatibant’s already-established use in Hereditary Angioedema (HAE) rather than a novel repurposing hypothesis (see rationale below).

Quick Overview

Item	Content
Original Indication	Not available in regulatory data (no licenses on file). Literature evidence (e.g., PMID 21284353) indicates Icatibant is authorised elsewhere for acute attacks of Hereditary Angioedema (HAE)
Predicted New Indication	C1 Inhibitor Deficiency
TxGNN Prediction Score	99.99%
Evidence Level	L1 (≥2 completed Phase 3 RCTs)
EU Market Status	Not marketed (Not marketed)
Number of Authorizations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism-of-action data is flagged as a data gap in DrugBank for this record. However, the evidence pack’s own literature abstracts consistently describe Icatibant as a synthetic decapeptide and selective bradykinin B2 receptor antagonist (PMID 24925394, PMID 21284353), used to block the bradykinin-mediated vascular permeability that drives angioedema attacks.

C1 Inhibitor (C1-INH) deficiency causes uncontrolled activation of the kallikrein-kinin system, resulting in excess bradykinin and the swelling attacks characteristic of Hereditary Angioedema. Blocking the bradykinin B2 receptor directly counteracts this downstream mechanism, which is mechanistically coherent regardless of whether C1-INH function is restored.

Importantly, the trial and literature evidence in this pack (e.g., NCT00097695, NCT00912093, PMID 21284353 noting Icatibant “is now authorised in the European Union”) indicates that Icatibant is already an established treatment for HAE due to C1-INH deficiency in multiple markets. This means the TxGNN “prediction” here largely reflects a true, already-known drug–disease relationship rather than a genuinely novel repurposing candidate. The practical question for this jurisdiction is less “is this mechanistically plausible” and more “why is the drug not yet marketed here, and what local regulatory/safety data is missing.”

Clinical Trial Evidence

Note: the disease-level search also returned trials for competitor drugs in the same disease space (BCX7353, KVD900, lanadelumab, plasma-derived/recombinant C1-INH concentrate, GNR-038) — these are excluded below as not directly evaluating Icatibant. The table lists the most relevant Icatibant-specific trials.

Trial Number	Phase	Status	Enrollment	Key Findings
NCT00097695	Phase 3	Completed	84	Randomized, double-blind, placebo-controlled study of SC icatibant for acute cutaneous/abdominal HAE attacks (pivotal registration trial)
NCT00912093	Phase 3	Completed	98	Randomized, double-blind, placebo-controlled study confirming efficacy and safety of icatibant vs. placebo for acute HAE attacks
NCT00500656	Phase 3	Completed	85	Randomized, controlled, parallel-group study comparing SC icatibant vs. oral tranexamic acid; icatibant showed faster time to symptom relief
NCT00997204	Phase 3	Completed	151	Open-label, multicenter study of self-administered SC icatibant — confirmed safety, tolerability, and convenience of home self-treatment
NCT03888755	Phase 3	Completed	8	Open-label study of icatibant efficacy, PK, and safety in Japanese HAE type I/II patients
NCT01386658	Phase 3	Completed	32	Multicenter, non-randomized PK/safety/tolerability study of single-dose icatibant in pediatric/adolescent HAE patients
NCT04654351	Phase 3	Completed	2	Non-randomized study of SC icatibant safety, efficacy, and PK in Japanese children/adolescents with acute HAE attacks
NCT01457430	Phase 4	Completed	19	Open-label study confirming self-administered icatibant does not change time to symptom resolution vs. clinic administration
NCT07290855	Phase 4	Completed	5	Safety/efficacy of icatibant injection (Icanticure®) for bradykinin-induced angioedema; notes NHI Taiwan reimbursement for diagnosed HAE
NCT01034969	N/A (Registry)	Completed	1,761	Icatibant Outcome Survey (IOS) — large prospective real-world registry documenting routine clinical safety/effectiveness outcomes

Literature Evidence

PMID	Year	Type	Journal	Key Findings
21284353	2010	Review	Prescrire International	Confirms icatibant (bradykinin B2 antagonist) authorised in the EU for HAE attacks; positions it relative to C1 esterase inhibitor
29757016	2018	Review	Expert Rev Clin Immunol	Reviews RCT and open-label extension data supporting icatibant safety/efficacy in adolescents and children (≥2 years) with C1-INH-HAE
23420425	2013	Systematic Review	Pneumonol Alergol Pol	Comparative effectiveness review of conestat alfa, human C1 esterase inhibitor, and icatibant for acute HAE attacks
22686628	2012	Observational	Allergy	Real-world study of icatibant in 8 patients with acquired C1-INH deficiency angioedema; 48 attacks treated with SC icatibant 30mg
35662289	2022	Registry-based	Clin Exp Allergy	Registry analysis of icatibant and C1-inhibitor use specifically for laryngeal HAE attacks
34965883	2021	Observational (Registry)	Allergy Asthma Clin Immunol	Icatibant Outcome Survey (IOS) data from Spain on HAE treatment outcomes
35871284	2023	Retrospective Study	J Clin Pharmacol	Retrospective review finding predominant off-label use of C1-INH concentrates and icatibant beyond the approved HAE indication
30280305	2018	Case Series	J Clin Immunol	Reports treatment of HAE attacks with icatibant and recombinant C1 inhibitor during pregnancy
36044174	2022	Review	Curr Allergy Asthma Rep	Reviews safety evidence for icatibant use during pregnancy, noting plasma-derived C1-INH remains first-line due to limited icatibant data
37898409	2024	Review	J Allergy Clin Immunol	Reviews HAE disease burden and treatment access (including icatibant) in the Asia-Pacific region

EU Market Information

No marketing authorizations are on file for this jurisdiction (total_licenses = 0, market status: Not marketed/Not marketed). This is notable given the substantial global clinical evidence base above, and should be clarified as part of any further evaluation (e.g., is the product simply not yet filed here, or was it discontinued/never sought?).

Safety Considerations

Please refer to the SmPC for safety information.

Conclusion and Next Steps

Decision: Hold

Rationale:

Efficacy evidence is strong (L1: ≥2 completed Phase 3 RCTs plus a large real-world registry of 1,761 patients), but this evidence documents Icatibant’s already-known role in HAE/C1-INH deficiency rather than a novel repurposing signal.
A Blocking data gap exists — no TFDA/local label (warnings, contraindications) is available, which per the evidence pack explicitly prevents entry into the S1 safety pre-assessment stage. Combined with the absence of any local marketing authorization, the candidate cannot responsibly advance past Hold.

To proceed, the following is needed:

TFDA (or equivalent local regulator) approved label: warnings, precautions, and contraindications (DG001)
Confirmed mechanism-of-action documentation via DrugBank API (DG002)
Drug-drug interaction (DDI) data — current query returned no results
Clarification of local regulatory/market status: reason for absence of any marketing authorization despite mature global evidence, and whether this candidate should be framed as a “new market entry” rather than a “new indication”
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.