Deferasirox: appraisal of safety and efficacy in long-term therapy

Efficacy and Safety of a Dispersible Tablet of GPO-Deferasirox Monotherapy among Children with Transfusion-Dependent Thalassemia and Iron Overload

The study aimed to determine efficacy and safety of generic deferasirox monotherapy. Deferasirox was administered in transfusion-induced iron overloaded thalassemia. Efficacy was defined as responders and nonresponders by ≤ 15 reduced serum ferritin from baseline. Adverse events were also monitored. Fifty-two patients with mainly Hb E/β-thalassemia at the mean (SD) age of 8.7 (4.1) years, were enrolled. The mean (SD) daily transfusion iron load was 0.47 (0.1) mg/kg and maximum daily deferasirox was 35.0 (6.2) mg/kg. Altogether, 52, 40 and 18 patients completed the first, second and third years of study, respectively. The median baseline serum ferritin 2,383 ng/mL decreased to 1,478, 1,038 and 1,268 ng/mL at the end of first, second and third years, respectively, with overall response rate at 73.1% (38/52). Patients with baseline serum ferritin >2,500 ng/mL showed a change in serum ferritin higher than those ≤2,500 ng/mL starting from the 9th month of chelation. Adverse events were found in 5 of 52 patients (9.6%) including transaminitis (n = 2), one each of proteinuria, rash and proximal tubular dysfunction which resolved after transient stopping or decreasing the chelation dose. Generic deferasirox was effective and safe among pediatric patients with transfusion-induced iron overloaded thalassemia.

Deferiprone for transfusional iron overload in sickle cell disease and other anemias: open-label study of up to 3 years

Long-term safety and efficacy data on the iron chelator deferiprone in sickle cell disease (SCD) and other anemias are limited. FIRST-EXT was a 2-year extension study of FIRST (Ferriprox in Patients With Iron Overload in Sickle Cell Disease Trial), a 1-year, randomized noninferiority study of deferiprone vs deferoxamine in these populations. Patients who entered FIRST-EXT continued to receive, or were switched to, deferiprone. Altogether, 134 patients were enrolled in FIRST-EXT (mean age: 16.2 years), with mean (SD) exposure to deferiprone of 2.1 (0.8) years over the 2 studies. The primary end point was safety. Secondary end points were change in liver iron concentration (LIC), cardiac T2∗, serum ferritin (SF), and the proportion of responders (≥20% improvement in efficacy measure). The most common adverse events considered at least possibly related to deferiprone were neutropenia (9.0%) and abdominal pain (7.5%). LIC (mg/g dry weight) decreased over time, with mean (SD) changes from baseline at each time point (year 1, -2.64 [4.64]; year 2, -3.91 [6.38]; year 3, -6.64 [7.72], all P < .0001). Mean SF levels (μg/L) decreased significantly after year 2 (-771, P = .0008) and year 3 (-1016, P = .0420). Responder rates for LIC and SF increased each year (LIC: year 1, 46.5%; year 2, 57.1%; year 3, 66.1%; SF: year 1, 35.2%; year 2, 55.2%; year 3, 70.9%). Cardiac T2∗ remained normal in all patients. In conclusion, long-term therapy with deferiprone was not associated with new safety concerns and led to continued and progressive reduction in iron load in individuals with SCD or other anemias. The trial was registered at www.clinicaltrials.gov as #NCT02443545.

Successful Deferasirox Rechallenge and Treating Through Reaction in a Patient with Challenge-Proven Mild Immediate Reaction: A Case Report

This is the first report of successful deferasirox administration, using graded challenge and treating through, in a patient with mild immediate hypersensitivity reaction. Beginning with drug graded challenges could indicate the eliciting dose and reaction severity which are important for the management plan in the next step. This approach could be a safe shortcut in a stable patient with a mild reaction and a long avoidance period.

Iron Overload in Myelodysplastic Syndromes: Pathophysiology, Consequences, Diagnosis, and Treatment

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic neoplasms varying in severity affecting one or more lines of hematopoiesis. Ineffective erythropoiesis results in dysregulation of iron metabolism. Most MDS patients have anemia, and some require regular red blood cell transfusions. These transfusions, in addition to factors of the disease itself, can result in iron overload (IO). Retrospective analyses suggest that MDS patients with IO have reduced overall survival and poorer outcomes following allogeneic stem cell transplant vs. those without IO. Iron chelation therapy (ICT; deferoxamine, deferasirox, or deferiprone) has been used to alleviate IO in other transfusion-dependent hematologic conditions (e.g., thalassemia), but its role in MDS has not been firmly established. A growing body of evidence suggests that ICT in MDS patients is an effective means for reducing transfusional IO and may significantly improve outcomes such as survival. The orally administered iron chelator deferasirox has been widely studied in MDS, and available studies have shown it to be generally well tolerated and effective in reducing IO in this population. The pathophysiology and clinical consequences of IO in MDS, as well as current methods for diagnosing and treating IO in these patients, are discussed.

Efficacy and adverse effects of oral chelating therapy (deferasirox) in multi-transfused Pakistani children with β-thalassemia major

Objective:

To determine the efficacy and adverse effects of oral chelation therapy (deferasirox) in multi-transfused β-thalassemia major patients visiting pediatric thalassemia clinic in Civil Hospital Karachi.

Methods:

This prospective study was conducted at pediatric thalassemia clinic of Civil Hospital Karachi. Hundred multi-transfused β-thalassemia patients registered in the clinic for oral iron chelation therapy were included in the study. Information regarding clinical and laboratory parameters including abdominal pain, jaundice, serum ferritin, creatinine and serum transaminase levels were recorded on a Performa and data was analyzed through SPSS 16.

Results:

Hundred patients were stratified into two age groups, 54% were below and 46% were above nine year. Majority were males, 62% and 38% were females. Abdominal pain 41%, nausea 31%, vomiting 15%, jaundice 15% and elevated serum creatinine 11.5% were frequently observed clinical adverse effects in this study. Serum glutamic pyruvic transaminase (SGPT) level was statistically significant compared with initial visit and six months after optimal chelation therapy (p=0.030). Although Serum ferritin was decreased but it was not statistically significant (p=0.929).

Conclusion:

Deferasirox is an effective oral chelation agent for β-thalassemia major patients. Most common adverse effects of the drug are abdominal pain, nausea, vomiting, and elevation of liver enzymes.

Influence of single-nucleotide polymorphisms on deferasirox C trough levels and effectiveness

Deferasirox (DFX) is the only once-daily oral chelator for iron overload and its pharmacokinetic has been related with response to therapy. Our aim was to evaluate DFX plasma concentrations according to single-nucleotide polymorphisms in genes involved in its metabolism (UGT1A1, UGT1A3, CYP1A1, CYP1A2 and CYP2D6) and elimination (MRP2 and BCRP1). Further aim was to define a plasma concentration cutoff value predicting an adequate response to therapy. Plasma concentrations were determined at the end of dosing interval (C trough) using an high-performance liquid chromatography-ultraviolet method. Allelic discrimination was performed by real-time PCR. C trough levels were influenced by UGT1A1C>T rs887829, CYP1A1C>A rs2606345, CYP1A2A>C rs762551, CYP1A2C>T rs2470890 and MRP2G>A rs2273697 polymorphisms. A DFX plasma efficacy cutoff value of 20,000 ng ml(-1) was identified; CYP1A1C>A rs2606345 AA and CYP1A2C>T rs2470890 TT genotypes may predict this value, suggesting a negative predictive role in therapy efficacy. Our data suggest the feasibility of a pharmacogenetic-based DFX dose personalization.

Iron chelation therapy with deferasirox in the management of iron overload in primary myelofibrosis

Deferasirox (DSX) is the principal option currently available for iron-chelation-therapy (ICT), principally in the management of myelodysplastic syndromes (MDS), while in primary myelofibrosis (PMF) the expertise is limited. We analyzed our experience in 10 PMF with transfusion-dependent anemia, treated with DSX from September 2010 to December 2013. The median dose tolerated of DSX was 750 mg/day (10 mg/kg/day), with 3 transient interruption of treatment for drug-related adverse events (AEs) and 3 definitive discontinuation for grade 3/4 AEs. According to IWG 2006 criteria, erythroid responses with DSX were observed in 4/10 patients (40%), 2 of them (20%) obtaining transfusion independence. Absolute changes in median serum ferritin levels (Delta ferritin) were greater in hematologic responder (HR) compared with non-responder (NR) patients, already at 6 months of ICT respect to baseline. Our preliminary data open new insights regarding the benefit of ICT not only in MDS, but also in PMF with the possibility to obtain an erythroid response, overall in 40 % of patients. HR patients receiving DSX seem to have a better survival and a lower incidence of leukemic transformation (PMF-BP). Delta ferritin evaluation at 6 months could represent a significant predictor for a different survival and PMF-BP. However, the tolerability of the drug seems to be lower compared to MDS, both in terms of lower median tolerated dose and for higher frequency of discontinuation for AEs. The biological mechanism of action of DSX in chronic myeloproliferative setting through an independent NF-κB inhibition could be involved, but further investigations are required.