Effects on hearing after long-term use of iron chelators in beta-thalassemia: Over twenty years of longitudinal follow-up

OBJECTIVE

The role of iron chelation in causing hearing loss (HL) is still unclear. The present study assessed the prevalence of HL among transfusion-dependent thalassemia (TDT) patients who underwent audiological follow-up over a 20-year period.

METHODS

We retrospectively analyzed clinical records and audiological tests from January 1990 (T0) to December 2022 (T22) of a group of TDT patients who received iron chelation therapy with deferoxamine (DFO), deferiprone (DFP) or deferasirox (DFX), in monotherapy or as part of combination therapy.

RESULTS

A total of 42 adult TDT patients (18 male, 24 female; age range: 41-55 years; mean age: 49.2 ± 3.7 years) were included in the study. At the T22 assessment, the overall prevalence of sensorineural HL was 23.8 % (10/42). When patients were stratified into two groups, with and without ototoxicity, no differences were observed for sex, age, BMI, creatinine level, pre-transfusional hemoglobin, start of transfusions, cardiac or hepatic T2 MRI; only ferritin serum values and duration of chelation were significantly higher (p = 0.02 and p = 0.01, respectively) in patients with hearing impairment in comparison to those with normal hearing.

CONCLUSION

This study with long-term follow-up suggests that iron chelation therapy might induce ototoxicity; therefore, a long and accurate audiological follow-up should be performed in TDT patients.

Efficacy and safety of deferoxamine, deferasirox and deferiprone triple iron chelator combination therapy for transfusion-dependent β-thalassaemia with very high iron overload: a protocol for randomised controlled clinical trial

INTRODUCTION

Despite the improvement in medical management, many patients with transfusion-dependent β-thalassaemia die prematurely due to transfusion-related iron overload. As per the current guidelines, the optimal chelation of iron cannot be achieved in many patients, even with two iron chelators at their maximum therapeutic doses. Here, we evaluate the efficacy and safety of triple combination treatment with deferoxamine, deferasirox and deferiprone over dual combination of deferoxamine and deferasirox on iron chelation in patients with transfusion-dependent β-thalassaemia with very high iron overload.

METHODS AND ANALYSIS

This is a single-centre, open-label, randomised, controlled clinical trial conducted at the Adult and Adolescent Thalassaemia Centre of Colombo North Teaching Hospital, Ragama, Sri Lanka. Patients with haematologically and genetically confirmed transfusion-dependent β-thalassaemia are enrolled and randomised into intervention or control groups. The intervention arm will receive a combination of oral deferasirox, oral deferiprone and subcutaneous deferoxamine for 6 months. The control arm will receive the combination of oral deferasirox and subcutaneous deferoxamine for 6 months. Reduction in iron overload, as measured by a reduction in the serum ferritin after completion of the treatment, will be the primary outcome measure. Reduction in liver and cardiac iron content as measured by T2* MRI and the side effect profile of trial medications are the secondary outcome measures.

ETHICS AND DISSEMINATION

Ethical approval for the study has been obtained from the Ethics Committee of the Faculty of Medicine, University of Kelaniya (Ref. P/06/02/2023). The trial results will be disseminated in scientific publications in reputed journals.

TRIAL REGISTRATION NUMBER

The trial is registered in the Sri Lanka Clinical Trials Registry (Ref: SLCTR/2023/010).

Efficacy of the iron-chelating agent, deferiprone, in patients with Parkinson's disease: A systematic review and meta-analysis

INTRODUCTION

Several studies have reported iron accumulation in the basal ganglia to be associated with the development of Parkinson's Disease (PD). Recently, a few trials have examined the efficacy of using the iron-chelating agent Deferiprone (DFP) for patients with PD. We conducted this meta-analysis to summarize and synthesize evidence from published randomized controlled trials about the efficacy of DFP for PD patients.

METHODS

A comprehensive literature search of four electronic databases was performed, spanning until February 2023. Relevant RCTs were selected, and their data were extracted and analyzed using the RevMan software. The primary outcome was the change in the Unified Parkinson's Disease Rating Scale (UPDRS-III).

RESULTS

Three RCTs with 431 patients were included in this analysis. DFP did not significantly improve UPDRS-III score compared to placebo (Standardized mean difference -0.06, 95% CI [-0.69, 0.58], low certainty evidence). However, it significantly reduced iron accumulation in the substantia nigra, putamen, and caudate as measured by T2*-weighted MRI (with high certainty evidence).

CONCLUSION

Current evidence does not support the use of DFP in PD patients. Future disease-modification trials with better population selection, adjustment for concomitant medications, and long-term follow up are recommended.

Longitudinal prospective comparison of pancreatic iron by magnetic resonance in thalassemia patients transfusion-dependent since early childhood treated with combination deferiprone-desferrioxamine vs deferiprone or deferasirox monotherapy

BACKGROUND

In transfusion-dependent thalassemia patients who started regular transfusions in early childhood, we prospectively and longitudinally evaluated the efficacy on pancreatic iron of a combined deferiprone (DFP) + desferrioxamine (DFO) regimen versus either oral iron chelator as monotherapy over a follow-up of 18 months.

MATERIALS AND METHODS

We selected patients consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia network who received a combined regimen of DFO+DFP (No.=28) or DFP (No.=61) or deferasirox (DFX) (No.=159) monotherapy between the two magnetic resonance imaging scans. Pancreatic iron overload was quantified by the T2* technique.

RESULTS

At baseline no patient in the combined treatment group had a normal global pancreas T2* (≥26 ms). At follow-up the percentage of patients who maintained a normal pancreas T2* was comparable between the DFP and DFX groups (57.1 vs 70%; p=0.517).Among the patients with pancreatic iron overload at baseline, global pancreatic T2* values were significantly lower in the combined DFO+DFP group than in the DFP or DFX groups. Since changes in global pancreas T2* values were negatively correlated with baseline pancreas T2* values, the percent changes in global pancreas T2* values, normalized for the baseline values, were considered. The percent changes in global pancreas T2* values were significantly higher in the combined DFO+DFP group than in either the DFP (p=0.036) or DFX (p=0.030) groups.

DISCUSSION

In transfusion-dependent patients who started regular transfusions in early childhood, combined DFP+DFO was significantly more effective in reducing pancreatic iron than was either DFP or DFX.

Deferiprone versus deferoxamine for transfusional iron overload in sickle cell disease and other anemias: Pediatric subgroup analysis of the randomized, open-label FIRST study

BACKGROUND

Children with sickle cell disease (SCD) who are chronically transfused often, require iron chelation therapy. There are limited data that allow for comparison of the efficacy and safety of the iron chelator deferiprone versus deferoxamine in children with SCD.

METHODS

This post hoc analysis of the phase 3b/4, randomized, open-label FIRST (Ferriprox in Patients with IRon Overload in Sickle Cell Disease Trial) study (NCT02041299) included patients 17 years and younger with SCD or other anemias receiving deferiprone or deferoxamine.

RESULTS

Overall, 142 patients were evaluated; mean ages were 10.5 and 11.7 years in the deferiprone and deferoxamine groups, respectively. At 12 months: mean change from baseline in liver iron concentration was -3.3 mg/g dry weight (dw) with deferiprone and -3.4 mg/g dw with deferoxamine (p = .8216); relative mean change (coefficient of variation %) in log cardiac T2* magnetic resonance imaging was 1.02 (21.8%) with deferiprone and 0.95 (19.5%) with deferoxamine (p = .0717); and the mean (standard error) change in serum ferritin levels was -133.0 (200.3) μg/L with deferiprone and -467.1 (244.1) μg/L with deferoxamine (p = .2924). The most common deferiprone-related adverse events (AEs) were upper abdominal pain (20.2%), vomiting (13.8%), pyrexia (9.6%), decreased neutrophil count (9.6%), increased alanine aminotransferase (ALT; 9.6%), and increased aspartate aminotransferase (AST; 9.6%). All cases of increased ALT, increased AST, and neutropenia resolved, most without intervention.

CONCLUSIONS

This post hoc analysis of pediatric patients from FIRST corroborated previous findings in adults that deferiprone is comparable to deferoxamine in reducing iron overload. No new safety concerns were observed. Deferiprone is an oral chelation option that could improve adherence and outcomes in children.

Drug Selection and Posology, Optimal Therapies and Risk/Benefit Assessment in Medicine: The Paradigm of Iron-Chelating Drugs

The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.

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.

Successful chelation in beta-thalassemia major in the 21st century

This century has seen a revolution the management of beta-thalassemia major. Over a 12-year period to 2016, we aimed to analyze the benefits of such advances. In 209 patients, independent of the chelation regimen, ferritin, cardiac T2* and liver iron concentration changes were evaluated. We defined chelation success (ChS) as no iron load in the heart and acceptable levels in the liver. Over 3 early magnetic resonance imagings, the same parameters were assessed in 2 subgroups, the only 2 that had sufficient patients continuing on 1 regimen and for a significant period of time, 1 on deferrioxamine (low iron load patients n = 41, Group A) and 1 on deferoxamine-deferiprone (iron overloaded n = 60, Group B). Finally, 28 deaths and causes were compared to those of an earlier period. The 209 patients significantly optimized those indices, while the number of patients with chelation success, increased from 6% to 51% (P < .0001). In group A, ChS after about 8 years increased from 21 to 46% (P = .006), while in Group B, from 0% to 60% (P < .001) after about 7 years. Deaths over the 2 periods showed significant reduction. Combined clearance of cardiac and liver iron (ChS) is feasible and should become the new target for all patients. This requires, serial magnetic resonance imagings and often prolonged intensified chelation for patients.

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.

A novel C19ORF12 mutation in two MPAN sisters treated with deferiprone

BACKGROUND

Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a rare and devastating disease caused by pathogenic mutations in C19orf12 gene. MPAN is characterized by pathological iron accumulation in the brain and fewer than 100 cases of MPAN have been described. Although the diagnosis of MPAN has achieved a great breakthrough with the application of the whole exome gene sequencing technology, the therapeutic effect of iron chelation therapy in MPAN remains controversial.

CASE PRESENTATION

We reported that two sisters from the same family diagnosed with MPAN had dramatically different responses to deferiprone (DFP) treatment. The diagnosis of MPAN were established based on typical clinical manifestations, physical examination, brain magnetic resonance imaging (MRI), cerebrospinal fluid analysis (CSF) and gene sequencing results. The clinical presentations of the two sisters with MPAN due to novel gene locus mutations were similar to those previously reported. There is no other difference in basic information except that the proband had a later onset age and fertility history. Both the proband and his second sister were treated with deferiprone (DFP), but they had dramatically different responses to the treatment. The proband's condition deteriorated sharply after treatment with DFP including psychiatric symptoms and movement disorders. However, the second sister of the proband became relatively stable after receiving the DFP treatment. After four years of follow-up, the patient still denies any new symptoms of neurological deficits.

CONCLUSION

The findings of this study enriched the MPAN gene database and indicated that DFP might ameliorate symptom progression in patients without severe autonomic neuropsychiatric impairment at the early stage of the disease.

Trial of Deferiprone in Parkinson's Disease

BACKGROUND

Iron content is increased in the substantia nigra of persons with Parkinson's disease and may contribute to the pathophysiology of the disorder. Early research suggests that the iron chelator deferiprone can reduce nigrostriatal iron content in persons with Parkinson's disease, but its effects on disease progression are unclear.

METHODS

We conducted a multicenter, phase 2, randomized, double-blind trial involving participants with newly diagnosed Parkinson's disease who had never received levodopa. Participants were assigned (in a 1:1 ratio) to receive oral deferiprone at a dose of 15 mg per kilogram of body weight twice daily or matched placebo for 36 weeks. Dopaminergic therapy was withheld unless deemed necessary for symptom control. The primary outcome was the change in the total score on the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS; range, 0 to 260, with higher scores indicating more severe impairment) at 36 weeks. Secondary and exploratory clinical outcomes at up to 40 weeks included measures of motor and nonmotor disability. Brain iron content measured with the use of magnetic resonance imaging was also an exploratory outcome.

RESULTS

A total of 372 participants were enrolled; 186 were assigned to receive deferiprone and 186 to receive placebo. Progression of symptoms led to the initiation of dopaminergic therapy in 22.0% of the participants in the deferiprone group and 2.7% of those in the placebo group. The mean MDS-UPDRS total score at baseline was 34.3 in the deferiprone group and 33.2 in the placebo group and increased (worsened) by 15.6 points and 6.3 points, respectively (difference, 9.3 points; 95% confidence interval, 6.3 to 12.2; P<0.001). Nigrostriatal iron content decreased more in the deferiprone group than in the placebo group. The main serious adverse events with deferiprone were agranulocytosis in 2 participants and neutropenia in 3 participants.

CONCLUSIONS

In participants with early Parkinson's disease who had never received levodopa and in whom treatment with dopaminergic medications was not planned, deferiprone was associated with worse scores in measures of parkinsonism than those with placebo over a period of 36 weeks. (Funded by the European Union Horizon 2020 program; FAIRPARK-II ClinicalTrials.gov number, NCT02655315.).

Benefits and Risks in Polypathology and Polypharmacotherapy Challenges in the Era of the Transition of Thalassaemia from a Fatal to a Chronic or Curable Disease

Beta thalassaemia major (TM), a potentially fatal haemoglobinopathy, has transformed from a fatal to a chronic disease in the last 30 years following the introduction of effective, personalised iron chelation protocols, in particular the use of oral deferiprone, which is most effective in the removal of excess iron from the heart. This transition in TM has been achieved by the accessibility to combination therapy with the other chelating drugs deferoxamine and deferasirox but also therapeutic advances in the treatment of related co-morbidities. The transition and design of effective personalised chelation protocols was facilitated by the development of new non-invasive diagnostic techniques for monitoring iron removal such as MRI T2*. Despite this progress, the transition in TM is mainly observed in developed countries, but not globally. Similarly, potential cures of TM with haemopoietic stem cell transplantation and gene therapy are available to selected TM patients but potentially carry high risk of toxicity. A global strategy is required for the transition efforts to become available for all TM patients worldwide. The same strategy could also benefit many other categories of transfusional iron loaded patients including other thalassaemias, sickle cell anaemia, myelodysplasia and leukaemia patients.

Deferiprone: A Forty-Year-Old Multi-Targeting Drug with Possible Activity against COVID-19 and Diseases of Similar Symptomatology

The need for preparing new strategies for the design of emergency drug therapies against COVID-19 and similar diseases in the future is rather urgent, considering the high rate of morbidity and especially mortality associated with COVID-19, which so far has exceeded 18 million lives. Such strategies could be conceived by targeting the causes and also the serious toxic side effects of the diseases, as well as associated biochemical and physiological pathways. Deferiprone (L1) is an EMA- and FDA-approved drug used worldwide for the treatment of iron overload and also other conditions where there are no effective treatments. The multi-potent effects and high safety record of L1 in iron loaded and non-iron loaded categories of patients suggests that L1 could be developed as a “magic bullet” drug against COVID-19 and diseases of similar symptomatology. The mode of action of L1 includes antiviral, antimicrobial, antioxidant, anti-hypoxic and anti-ferroptotic effects, iron buffering interactions with transferrin, iron mobilizing effects from ferritin, macrophages and other cells involved in the immune response and hyperinflammation, as well as many other therapeutic interventions. Similarly, several pharmacological and other characteristics of L1, including extensive tissue distribution and low cost of production, increase the prospect of worldwide availability, as well as many other therapeutic approach strategies involving drug combinations, adjuvant therapies and disease prevention.

Deferiprone Treatment in Aged Transgenic Tau Mice Improves Y-Maze Performance and Alters Tau Pathology

The accumulation of neurofibrillary tangles (NFTs), which is composed of abnormally hyperphosphorylated tau aggregates, is the classic neuropathology associated with cognitive dysfunction in tauopathies such as Alzheimer's disease (AD). However, there is an emerging theory suggesting that dysregulation in cerebral iron may contribute to NFT formation. Iron is speculated to bind to tau and induce conformational changes of the protein, potentially leading to subsequent aggregation and cognitive decline. Deferiprone (DFP) is a clinically available iron chelator, which has demonstrated potential therapeutic advantages of chelating iron in neurodegenerative disorders, and is currently in clinical trials for AD. However, its effect on tau pathology remains unclear. Here, we report the effects of short-term DFP treatment (4 weeks, 100 mg/kg/daily, via oral gavage) in a mixed-gender cohort of the rTg(tauP301L)4510 mouse model of tauopathy. Our results revealed that DFP improved Y-maze and open field performance, accompanied by a 28% decrease in brain iron levels, measured by inductively coupled plasma mass spectrometry (ICP-MS) and reduced AT8-labeled p-tau within the hippocampus in transgenic tau mice. This data supports the notion that iron may play a neurotoxic role in tauopathies and may be a potential therapeutic target for this class of disorders that can be modulated by the clinically available metal chelator DFP.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model

Introduction

Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery.

Materials and methods

112 adult (8–10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups.

Results

Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats.

Conclusions

Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

Iron Chelation in Local Infection

Iron is an essential element in multiple biochemical pathways in humans and pathogens. As part of the innate immune response in local infection, iron availability is restricted locally in order to reduce overproduction of reactive oxygen species by the host and to attenuate bacterial growth. This physiological regulation represents the rationale for the therapeutic use of iron chelators to support induced iron deprivation and to treat infections. In this review paper we discuss the importance of iron regulation through examples of local infection and the potential of iron chelation in treating infection.

Deferiprone (DFP) Targets Cancer Stem Cell (CSC) Propagation by Inhibiting Mitochondrial Metabolism and Inducing ROS Production

Deferiprone (DFP), also known as Ferriprox, is an FDA-approved, orally active, iron chelator that is currently used clinically for the treatment of iron-overload, especially in thalassaemia major. As iron is a critical factor in Fe-S cluster assembly that is absolutely required for the metabolic function of mitochondria, we hypothesized that DFP treatment could be used to selectively target mitochondria in cancer stem cells (CSCs). For this purpose, we used two ER(+) human breast cancer cell lines, namely MCF7 and T47D cells, as model systems. More specifically, a 3D tumorsphere assay was employed as a functional readout of CSC activity which measures anchorage-independent growth under low attachment conditions. Here, we show that DFP dose dependently inhibited the propagation of CSCs, with an IC-50 of ~100 nM for MCF7 and an IC-50 of ~0.5 to 1 μM for T47D cells, making DFP one the most potent FDA-approved drugs that we and others have thus far identified for targeting CSCs. Mechanistically, we show that high concentrations of DFP metabolically targeted both mitochondrial oxygen consumption (OCR) and glycolysis (extracellular acidification rates (ECAR)) in MCF7 and T47D cell monolayers. Most importantly, we demonstrate that DFP also induced a generalized increase in reactive oxygen species (ROS) and mitochondrial superoxide production, and its effects reverted in the presence of N-acetyl-cysteine (NAC). Therefore, we propose that DFP is a new candidate therapeutic for drug repurposing and for Phase II clinical trials aimed at eradicating CSCs.

The Iron Chelator Deferiprone Improves the Phenotype in a Mouse Model of Tauopathy

BACKGROUND

Abnormally hyperphosphorylated tau is a defining pathological feature of tauopathies, such as Alzheimer's disease (AD), and accumulating evidence suggests a role for iron in mediating tau pathology that may lead to cognitive decline in these conditions. The metal chelator deferiprone (DFP), which has a high affinity for iron, is currently in clinical trials for AD and Parkinson's disease. However, the effect of DFP on tau pathology remains underexplored.

OBJECTIVE

We aimed to investigate the impact of chronic DFP treatment on tau pathology using a well-characterized mouse model of tauopathy (rTg(tauP301L)4510).

METHODS

Animals were treated daily with DFP (100 mg/kg) via oral gavage for 16 weeks. After 14 weeks, mice were tested in the Y-maze, open field, Morris water maze, and rotorod. At the end of the study, brain tissue was collected to examine metal levels (using inductively coupled plasma-mass spectrometry) and for western blot analysis of DFP on tau and iron associated pathways.

RESULTS

DFP significantly reduced anxiety-like behavior, and revealed a trend toward improved cognitive function. This was accompanied by a decrease in brain iron levels and sarkosyl-insoluble tau. Our data also showed downregulation of the tau kinases glycogen synthase kinase 3β and cyclin dependent kinase-5 in DFP treated mice and an increase in the methylation of the catalytic subunit of protein phosphatase 2A.

CONCLUSION

These data support the hypothesis that suggests that iron plays a neurotoxic role in tauopathies and may be a potential therapeutic target for this class of disorders.

Safety and efficacy of deferiprone for pantothenate kinase-associated neurodegeneration: a randomised, double-blind, controlled trial and an open-label extension study

BACKGROUND

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare genetic disorder characterised by progressive generalised dystonia and brain iron accumulation. We assessed whether the iron chelator deferiprone can reduce brain iron and slow disease progression.

METHODS

We did an 18-month, randomised, double-blind, placebo-controlled trial (TIRCON2012V1), followed by a pre-planned 18-month, open-label extension study, in patients with PKAN in four hospitals in Germany, Italy, England, and the USA. Patients aged 4 years or older with a genetically confirmed diagnosis of PKAN, a total score of at least 3 points on the Barry-Albright Dystonia (BAD) scale, and no evidence of iron deficiency, neutropenia, or abnormal hepatic or renal function, were randomly allocated (2:1) to receive an oral solution of either deferiprone (30 mg/kg per day divided into two equal doses) or placebo for 18 months. Randomisation was done with a centralised computer random number generator and with stratification based on age group at onset of symptoms. Patients were allocated to groups by a randomisation team not masked for study intervention that was independent of the study. Patients, caregivers, and investigators were masked to treatment allocation. Co-primary endpoints were the change from baseline to month 18 in the total score on the BAD scale (which measures severity of dystonia in eight body regions) and the score at month 18 on the Patient Global Impression of Improvement (PGI-I) scale, which is a patient-reported interpretation of symptom improvement. Efficacy analyses were done on all patients who received at least one dose of the study drug and who provided a baseline and at least one post-baseline efficacy assessment. Safety analyses were done for all patients who received at least one dose of the study drug. Patients who completed the randomised trial were eligible to enrol in a single-arm, open-label extension study of another 18 months, in which all participants received deferiprone with the same regimen as the main study. The trial was registered on ClinicalTrials.gov, number NCT01741532, and EudraCT, number 2012-000845-11.

FINDINGS

Following a screening of 100 prospective patients, 88 were randomly assigned to the deferiprone group (n=58) or placebo group (n=30) between Dec 13, 2012, and April 21, 2015. Of these, 76 patients completed the study (49 in the deferiprone group and 27 in the placebo group). After 18 months, the BAD score worsened by a mean of 2·48 points (SE 0·63) in patients in the deferiprone group versus 3·99 points (0·82) for patients in the control group (difference -1·51 points, 95% CI -3·19 to 0·16, p=0·076). No subjective change was detected as assessed by the PGI-I scale: mean scores at month 18 were 4·6 points (SE 0·3) for patients in the deferiprone group versus 4·7 points (0·4) for those in the placebo group (p=0·728). In the extension study, patients continuing deferiprone retained a similar rate of disease progression as assessed by the BAD scale (1·9 points [0·5] in the first 18 months vs 1·4 points [0·4] in the second 18 months, p=0·268), whereas progression in patients switching from placebo to deferiprone seemed to slow (4·4 points [1·1] vs 1·4 points [0·9], p=0·021). Patients did not detect a change in their condition after the additional 18 months of treatment as assessed by the PGI-I scale, with mean scores of 4·1 points [0·2] in the deferiprone-deferiprone group and of 4·7 points [0·3] in the placebo-deferiprone group. Deferiprone was well tolerated and adverse events were similar between the treatment groups, except for anaemia, which was seen in 12 (21%) of 58 patients in the deferiprone group, but was not seen in any patients in the placebo group. No patient discontinued therapy because of anaemia, and three discontinued because of moderate neutropenia. There was one death in each group of the extension study and both were secondary to aspiration. Neither of these events was considered related to deferiprone use.

INTERPRETATION

Deferiprone was well tolerated, achieved target engagement (lowering of iron in the basal ganglia), and seemed to somewhat slow disease progression at 18 months, although not significantly, as assessed by the BAD scale. These findings were corroborated by the results of an additional 18 months of treatment in the extension study. The subjective PGI-I scale was largely unchanged during both study periods, indicating that might not be an adequate tool for assessment of disease progression in patients with PKAN. Our trial provides the first indication of a decrease in disease progression in patients with neurodegeneration with brain iron accumulation. The extensive information collected and long follow-up of patients in the trial will improve the definition of appropriate endpoints, increase the understanding of the natural history, and thus help to shape the design of future trials in this ultra-orphan disease.

FUNDING

European Commission, US Food and Drug Administration, and ApoPharma Inc.