Strategies for managing transfusional iron overload: conventional treatments and novel strategies

[Pure red cell aplasia: Diagnosis, classification and treatment]

Pure red cell aplasia (PRCA) is a rare anemia characterised by profound reticulocytopenia caused by a marked reduction in bone marrow erythroblasts, without abnormalities in other blood lineages. Blackfan-Diamond anemia is an inherited ribosomopathy responsible for a hereditary form of PRCA. Acquired PRCA are separated in primary and secondary forms, including Parvovirus B19 infection, thymoma, lymphoproliferative disorders, autoimmune diseases (lupus) and drug-induced PRCA. The pathophysiology of PRCA is not fully understood and involves both humoral and T lymphocyte autoreactive cells. In Parvovirus B19-related PRCA, treatment is based on polyvalent immunoglobulins. Thymectomy for thymoma is mandatory but results in prolonged remission in a limited number of cases. The therapeutic strategy is based on expert opinion: corticosteroids in monotherapy provide few sustained responses. The choice of an additional immunosuppressant drug is guided by the presence of an underlying disease. In most cases, cyclosporine A is the first choice providing the best response rate but requires a concentration monitoring (150 to 250 ng/mL). The second choice is cyclophosphamide in large granular lymphocyte leukaemia. Sirolimus (mTOR inhibitor) seems to be a promising option especially in refractory cases. Transfusion independence is the main objective. If the patient receives numerous red blood cell transfusions (> 20 packs), iron overload assessment is crucial to initiate an iron chelation. A retrospective and prospective national cohort (EPIC-F) has been set up and is now available to include each case of PRCA to improve the knowledge of this disease and to optimize the therapeutic strategy.

The molecular and metabolic landscape of iron and ferroptosis in cardiovascular disease

The maintenance of iron homeostasis is essential for proper cardiac function. A growing body of evidence suggests that iron imbalance is the common denominator in many subtypes of cardiovascular disease. In the past 10 years, ferroptosis, an iron-dependent form of regulated cell death, has become increasingly recognized as an important process that mediates the pathogenesis and progression of numerous cardiovascular diseases, including atherosclerosis, drug-induced heart failure, myocardial ischaemia-reperfusion injury, sepsis-induced cardiomyopathy, arrhythmia and diabetic cardiomyopathy. Therefore, a thorough understanding of the mechanisms involved in the regulation of iron metabolism and ferroptosis in cardiomyocytes might lead to improvements in disease management. In this Review, we summarize the relationship between the metabolic and molecular pathways of iron signalling and ferroptosis in the context of cardiovascular disease. We also discuss the potential targets of ferroptosis in the treatment of cardiovascular disease and describe the current limitations and future directions of these novel treatment targets.

Effect of Aging on Deferasirox Therapy in Transfusion-dependent Patients. A prospective-retrospective, cohort-study

BACKGROUND

Iron-chelation therapy is life-saving in patients on a chronic transfusion regimen as it reduces organ damage related to iron deposition in the tissues. Deferasirox, an iron-chelator, is characterized by pharmacokinetics variability, and some patients may discontinue the treatment due to toxicities.

OBJECTIVE

Understanding whether deferasirox plasma levels are related to patients' specific characteristics could help optimize DFX dosage.

METHODS

We analyzed deferasirox plasma concentration in 57 transfusion-dependent anemic patients using the HPLC method in this prospective-retrospective cohort study. All outpatients (3 to 98 years) were treated with deferasirox (film-coated tablet) for at least one year (median dose, 16.5 mg/Kg once a day). Deferasirox plasma concentration was normalized for dose/Kg (C/dose) and corrected with a linear regression model that relates C/dose and the time of blood sampling (Cref/dose).

RESULTS

No significant differences in Cref/dose were found between males and females, either between different types of hemoglobinopathies or depending on the presence of the UGT1A1*28 polymorphism. Cref/dose has a positive and significant correlation with age, creatinine, and direct bilirubin. Cref/dose, instead, has a negative and significant correlation with Liver Iron Concentration (LIC), ferritin, and eGFR. Cref/dose was significantly different between three age categories <18yrs, 18-50yrs, and >50yrs, with Cref/dose median values of 1.0, 1.2, and 1.5, respectively.

CONCLUSION

The study evidenced that to ensure the efficacy of deferasirox in terms of control over LIC and, at the same time, a lesser influence on renal function, the dose of the drug to be administered to an elderly patient could be reduced.

Which part of the blood in the knee joint is responsible for its detrimental effects? (An experimental study on the knee joint in rabbits)

AIM

This study aims to determine the potential causative elements which are responsible for the cartilage damage in case of frequent intra-articular bleeding and to evaluate the effects of intra-articular free iron and chelation of iron in the knee joint.

METHODS

Thirty-five New Zealand rabbits were randomly divided into five groups according to substances injected into their knee joints. Plasma (group I) and cellular components (group II) of the blood harvested from the rabbits, iron (ferric hydroxide sucrose) (group III), iron&chelator (group IV) and only chelator (deferoxamine mesylate) (group V) were injected into their right knees three times a week for 12 weeks. The joint surface was examined histologically according to the classification system modified from Colombo et al. The changes in the synovial tissue were evaluated according to the scoring system modified from Madhok et al.

RESULTS

Cartilage and synovial abnormality scores were significantly higher in all study groups when compared to their own controls (p < 0.0001). Cartilage scores of groups I and V were significantly lower when compared to groups III and IV (p = 0.002 for group I and p = 0.003 for group V). Synovial abnormality score of group I was significantly lower than scores of groups III and IV (p = 0.001); and of group V lower than groups III and IV (p = 0.003 and p = 0.001, respectively).

CONCLUSIONS

All substances tested in this study caused a certain amount of damage in the cartilage tissue and led to synovial abnormalities. Both iron and iron&chelator caused more damage in the cartilage and led to more advanced synovial changes when compared to the plasma component of blood and chelator itself. Influence of iron and iron&chelators were found to be similar showing that chelation was inadequate in antagonizing the detrimental effects of iron.

Pure red cell aplasia in systemic lupus erythematosus, a nationwide retrospective cohort and review of the literature

OBJECTIVES

To characterize the clinical and biological course, management and response to treatment in Systemic Lupus Erythematosus (SLE)-associated Pure Red Cell Aplasia (PRCA).

METHODS

Nationwide multicentre retrospective cohort study. From 2006 to 2018, we included adults with a diagnosis of PRCA supported by bone-marrow examination and SLE or biologic manifestations of SLE after ruling out parvovirus B19 infection.

RESULTS

We enrolled 24 patients (20 women). SLE was diagnosed before PRCA for 14 patients (median delay 81 months). At PRCA diagnosis, mean age, haemoglobin level and reticulocyte and differential erythroblast count were 39.2 ± 13.2 years, 62 ± 20 g/L, 9.1 ± 7.6 x 109/L and 2.8 ± 2.5%, respectively. Eleven (45%) patients experienced multiple PRCA flares (median 6, range: 2-11). Corticosteroid therapy resulted in only three complete sustained responses, and 19 (79%) patients required immunosuppressive agents with highly variable regimens. After a median follow-up of 76 months (range 13-173), 17 (71%) patients showed complete response for PRCA, five (21%) partial response and two (8%) treatment failure. In total, 21 (87%) patients required red-blood-cell transfusion; five had a diagnosis of transfusion-related iron overload. Eighteen (75%) patients experienced severe infectious events requiring hospitalization.

CONCLUSION

SLE-associated PRCA is a severe condition. Repeated red-blood-cell transfusions and several lines of immunosuppressant therapy are mostly required with high risk of severe infectious events and iron overload. Despite sustained response for PRCA and SLE obtained in most patients, the best therapeutic strategy remains to be determined.

Two-year long safety and efficacy of deferasirox film-coated tablets in patients with thalassemia or lower/intermediate risk MDS: phase 3 results from a subset of patients previously treated with deferasirox in the ECLIPSE study

Background

Despite the proven benefits of iron chelation therapy (ICT) in the management of chronic iron overload and related complications, compliance to long-term ICT is challenging. Results from the ECLIPSE study, an open-label, randomized, multicenter, 2-arm, phase 2 study evaluated the safety of deferasirox dispersible tablet and film-coated tablet (FCT) formulations in patients with transfusion-dependent thalassemia (TDT) or very low, low, or intermediate risk myelodysplastic syndrome (MDS) treated over 24 weeks.

Methods

The aim of the current study (a 2-year, open-label, multicenter, single-arm, phase 3 study) is to evaluate the long-term safety and efficacy of deferasirox FCT in a subset of patients with TDT or lower/intermediate-risk MDS treated for 2 years after the completion of 24 weeks of treatment with deferasirox in the ECLIPSE phase 2 study.

Results

Of 53 patients enrolled, 34 (64.2%) completed treatment and study. Adverse events (AEs) reported in most patients (~ 70%) were of mild to moderate severity. Headache and diarrhea were the most frequently (> 25%) reported AEs. None of the serious AEs (including 1 death) were considered treatment related. No new safety signal was identified, and long-term safety of deferasirox FCT was consistent with the known safety profile of deferasirox. No major concerns associated with gastrointestinal tolerability, renal safety, or hematological abnormalities (thrombocytopenia/neutropenia) were reported during the 2 years. Patients receiving deferasirox FCT had a treatment compliance (by pill count) of ~ 90% and persistence (continuous use for ≥ 30 days) of > 95%. Reduction in serum ferritin level was almost consistent starting from week 2 across all post-baseline time points (relative reduction: month 6, 19%; month 12, 29%).

Conclusions

The results from this 2-year interventional study suggest that the recommended dosing of deferasirox FCT, with better tolerability, palatability, and compliance, offers a favorable option of ICT for long-term management of iron overload and associated complications in TDT.

Trial registration ClinicalTrials.gov, NCT02720536. Registered 28 March 2016, https://www.clinicaltrials.gov/ct2/show/NCT02720536