The safety and acceptability of twice-daily deferiprone for transfusional iron overload: A multicentre, open-label, phase 2 study

Real-world evidence: Long-term safety of deferiprone in a large cohort of patients with sickle cell disease enrolled in a registry for up to 10 years

Patients with sickle cell disease (SCD) and other anemias who receive blood transfusions are at risk of organ damage due to transfusional iron overload. Deferiprone is an iron chelator with a well-established safety and efficacy profile that is indicated for the treatment of transfusional iron overload. Here, we report safety data from the large-scale, retrospective Ferriprox® Total Care Registry, which involved all patients with SCD taking deferiprone following the 2011 approval of deferiprone in the United States through August 2020. A total of 634 patients who had initiated deferiprone treatment were included. The mean (SD) duration of deferiprone exposure in the registry was 1.6 (1.6) years (range 0 to 9.7 years). In the overall patient population (N = 634), 64.7% (n = 410) of patients reported a total of 1885 adverse events (AEs). In subgroup analyses, 54.6% (n = 71) of pediatric patients and 67.3% (n = 339) of adult patients reported AEs. The most common AEs reported in patients receiving deferiprone were sickle cell crisis (22.7%), nausea (12.1%), vomiting (8.7%), abdominal discomfort (5.4%), and fatigue (5.4%). Neutropenia was reported in four (0.6%) patients and severe neutropenia/agranulocytosis (defined as absolute neutrophil count <0.5 × 109 /L) was reported in two (0.3%) patients. Of patients with evaluable data, all cases of neutropenia and severe neutropenia/agranulocytosis resolved with deferiprone discontinuation. Results from the nearly 10 years of real-world data collected in the Ferriprox® Total Care Registry demonstrate that deferiprone is safe and well tolerated in patients with SCD or other anemias who have transfusional iron overload.

Combination chelation therapy

Combination chelation therapies are considered in transfusion-dependent thalassemia patients for whom monotherapy regimens have failed to achieve iron balance or intensification of iron chelation therapy is required for the rapid reduction of excess iron to avoid permanent organ damage. Combination chelation may provide a more flexible approach for individualizing chelation therapy, thereby improving tolerability, adherence, and quality of life. In principle, iron chelators can be combined with an infinite number of dosing regimens; these involve simultaneous or sequential exposure to the chelators on the same day or alternating the drugs on different days. Clinical studies have established the safety and efficacy of chelation combinations. However, real-life data with combination therapies indicate the significance of compliance for a meaningful reduction in iron overload compared to monotherapies.

Adherence to Iron Chelation Therapy Among Children with Beta Thalassemia Major: A Multicenter Cross-Sectional Study

BACKGROUND

Adherence to iron chelation therapy (ICT) remains an issue among thalassemia patients. This study aimed to determine the prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia and the factors associated with it.

METHODS

This was a cross-sectional study conducted between November 2019 and November 2021 at seven tertiary hospitals in Malaysia. Participants registered with Malaysian Thalassemia Registry were recruited by convenience sampling. Adherence was measured via pill count and self-reported adherence. Knowledge about thalassemia and ICT was measured using a questionnaire from Modul Thalassemia by Ministry of Health of Malaysia. A decision tree was used to identify predictors of non-adherence.

RESULTS

A total of 135 patients were recruited. The prevalence of non-adherence to ICT in those who took subcutaneous ± oral medications was 47.5% (95% CI: 31.5%, 63.9%) and the prevalence of non-adherence to ICT in those who took oral medications only was 21.1% (95% CI: 13.4%, 30.6%). The median knowledge score was 67.5% (IQR 15%). A decision tree has identified two factors associated with non-adherence. They were ICT's route of administration and knowledge score. Out of 100 patients who were on oral medications only, 79 were expected to adhere. Out of 100 patients who were on subcutaneous ± oral medications and scored less than 56.25% in knowledge questionnaire, 86 were expected to non-adhere. Based on the logistic regression, the odds of non-adherence in patients who took oral medications only was 71% lower than the odds of non-adherence in patients who took subcutaneous ± oral medications (OR = 0.29; 95% CI = 0.13, 0.65; p = .002).

CONCLUSION

The prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia was 20/95 (21.1%) in those who took oral medications only and the prevalence of non-adherence was 19/40 (47.5%) in those who took subcutaneous ± oral medications. The factors associated with non-adherence were ICT's route of administration and knowledge score.

Clinical Challenges with Iron Chelation in Beta Thalassemia

Conventional therapy for severe thalassemia includes regular red cell transfusions and iron chelation therapy to prevent and treat complications of iron overload. Iron chelation is very effective when appropriately used, but inadequate iron chelation therapy continues to contribute to preventable morbidity and mortality in transfusion-dependent thalassemia. Factors that contribute to suboptimal iron chelation include poor adherence, variable pharmacokinetics, chelator adverse effects, and difficulties with precise monitoring of response. The regular assessment of adherence, adverse effects, and iron burden with appropriate treatment adjustments is necessary to optimize patient outcomes.

Deferiprone and Iron-Maltol: Forty Years since Their Discovery and Insights into Their Drug Design, Development, Clinical Use and Future Prospects

The historical insights and background of the discovery, development and clinical use of deferiprone (L1) and the maltol-iron complex, which were discovered over 40 years ago, highlight the difficulties, complexities and efforts in general orphan drug development programs originating from academic centers. Deferiprone is widely used for the removal of excess iron in the treatment of iron overload diseases, but also in many other diseases associated with iron toxicity, as well as the modulation of iron metabolism pathways. The maltol-iron complex is a recently approved drug used for increasing iron intake in the treatment of iron deficiency anemia, a condition affecting one-third to one-quarter of the world's population. Detailed insights into different aspects of drug development associated with L1 and the maltol-iron complex are revealed, including theoretical concepts of invention; drug discovery; new chemical synthesis; in vitro, in vivo and clinical screening; toxicology; pharmacology; and the optimization of dose protocols. The prospects of the application of these two drugs in many other diseases are discussed under the light of competing drugs from other academic and commercial centers and also different regulatory authorities. The underlying scientific and other strategies, as well as the many limitations in the present global scene of pharmaceuticals, are also highlighted, with an emphasis on the priorities for orphan drug and emergency medicine development, including the roles of the academic scientific community, pharmaceutical companies and patient organizations.

An evaluation of deferiprone as twice-a-day tablets or in combination therapy for the treatment of transfusional iron overload in thalassemia syndromes

INTRODUCTION

Regular blood transfusions in patients with thalassemia syndromes can cause iron overload resulting in complications including cirrhosis, heart problems, or endocrine abnormalities. To prevent iron overload toxicity in these patients, three iron chelators are currently FDA-approved for use: deferoxamine, deferasirox, and deferiprone. In the United States, deferiprone has been approved for three times daily dosing since 2011 and has recently gained approval for twice-daily administration.

AREAS COVERED

A PubMed literature search was performed with the keywords 'deferiprone' and 'thalassemia.' Relevant original research studying deferiprone's effects on transfusional iron overload in patients with thalassemia syndromes was included. Exclusion criteria included case reports and review papers. Deferiprone is effective at reducing serum ferritin levels in patients with iron overload. Twice-daily administration provides a similar level of iron chelation as three times daily dosing with a comparable side effect profile and increased patient acceptability.

EXPERT OPINION

New studies are highlighting deferiprone's potential for combination therapy with either deferoxamine or deferasirox to improve iron chelation. Deferiprone's ability to significantly decrease cardiac and liver iron content can be utilized in other transfusion-dependent hematologic conditions, as evidenced by its recent approval for use in the United States for sickle cell disease or other anemias.