Deferiprone

證據等級: L5

預測適應症: 10 個

Deferiprone: From Transfusional Iron Overload to Hepatic Porphyria

One-Sentence Summary

Deferiprone is an oral iron chelator established for treating transfusional iron overload in patients with thalassemia major, targeting toxic intracellular iron accumulation in the heart, liver, and other organs. The TxGNN model predicts it may be effective for Hepatic Porphyria, particularly subtypes where excess hepatic iron worsens porphyrin-driven oxidative damage. Currently 0 registered clinical trials and 2 preclinical publications support this direction, placing the evidence at L4 (mechanism/animal model level).

Quick Overview

Item	Content
Original Indication	Transfusional iron overload in thalassemia major
Predicted New Indication	Hepatic Porphyria
TxGNN Prediction Score	99.20%
Evidence Level	L4
EU Market Status	Not marketed (0 licenses in regulatory database)
Number of Authorizations	0
Recommended Decision	Hold

Why Is This Prediction Reasonable?

Detailed mechanism of action data is not available in this Evidence Pack. Based on known pharmacological information, Deferiprone (known as L1) is an oral bidentate iron chelator that binds ferric iron (Fe³⁺) in a 3:1 molar ratio and forms a stable complex excreted renally. Its key pharmacological advantage over deferoxamine is membrane permeability: deferiprone enters cells and removes iron from intracellular compartments, including cardiac myocytes, hepatocytes, and erythroid precursors. This property underlies its proven superiority over deferoxamine in clearing myocardial iron in thalassemia major patients.

In hepatic porphyria — specifically Congenital Erythropoietic Porphyria (CEP) and Porphyria Cutanea Tarda (PCT) — hepatic iron overload functions as a pathogenic cofactor. Excess intracellular iron catalyzes Fenton-type reactions, generating reactive oxygen species that amplify oxidative damage from accumulating non-physiological porphyrin isomers. This worsens both skin photosensitivity and chronic hemolytic anemia. Deferiprone’s ability to chelate intracellular iron provides a mechanistically coherent rationale: reducing the iron substrate for Fenton chemistry could attenuate the porphyrin-iron oxidative cascade in iron-overloaded subtypes.

However, “hepatic porphyria” is a heterogeneous diagnostic category that includes diseases with fundamentally different pathophysiology. The mechanistic rationale applies selectively to iron-driven subtypes (CEP, PCT). Acute hepatic porphyrias — Acute Intermittent Porphyria (AIP), Variegate Porphyria (VP), and Hereditary Coproporphyria (HCP) — are triggered by enzyme deficiencies in the heme synthesis pathway and are not primarily iron-mediated. Deferiprone is unlikely to provide benefit in these subtypes and the prediction should be interpreted with this heterogeneity in mind.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
32678895	2020	Animal model + possible case series	Blood	Iron chelation rescued hemolytic anemia and skin photosensitivity in a CEP mouse model (UROS-deficient); results suggest that iron reduction — targeting the Fenton cascade — may be a viable therapeutic strategy in CEP
17854053	2007	Animal experiment	Hepatology	Deferiprone reduced hepatic uroporphyrin (URO) accumulation in Hfe⁻/⁻ mice given ALA (a PCT model); efficacy was comparable to iron-deficient diet, validating iron depletion as a mechanistic intervention in PCT-like uroporphyria

Safety Considerations

Please refer to the SmPC for safety information.

Note: Two data gaps have been identified that affect safety evaluation:

DG001 (Blocking): TFDA labeling warnings and contraindications are unavailable — full S1 safety screening cannot be completed.

DG002 (High): MOA documentation is absent — limits mechanistic link analysis.

Conclusion and Next Steps

Decision: Hold

Rationale: All available evidence is preclinical (L4: animal models only), and the target population within “hepatic porphyria” is narrow — the mechanistic rationale holds for iron-overloaded subtypes (CEP, PCT) but not for acute hepatic porphyrias. Without human clinical data and with critical safety data gaps unresolved, this candidate is not ready to advance.

To proceed, the following is needed:

Subtype specificity: Restrict the repurposing target to CEP and/or PCT with documented iron overload, rather than the broader “hepatic porphyria” grouping
Safety gap resolution (DG001): Retrieve SmPC or TFDA labeling to complete contraindication and warning review
MOA documentation (DG002): Obtain structured DrugBank MOA data to strengthen the mechanistic rationale dossier
Human case evidence: Identify published case reports or retrospective series of CEP/PCT patients who received deferiprone, to establish whether preclinical benefits translate clinically
Biomarker eligibility criteria: Define serum ferritin and transferrin saturation thresholds as inclusion criteria for any future pilot study, ensuring iron overload is confirmed in enrolled patients
Disclaimer

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