Long-term safety and erythroid response with luspatercept treatment in patients with ß-thalassemia.

Background: ß-thalassemia is a hereditary blood disorder resulting in ineffective erythropoiesis and anemia. Management of anemia with regular blood transfusions is associated with complications including iron overload. Here, we report long-term safety and efficacy results of the first clinical study of luspatercept in ß-thalassemia, initiated in 2013, enrolling adults with both nontransfusion-dependent (NTD) and transfusion-dependent (TD) ß-thalassemia. Objectives: The objective was to report long-term safety data, for up to 5 years of treatment, for 64 patients with TD or NTD ß-thalassemia, and long-term efficacy data for a subset of 63 patients with ß-thalassemia who received high-dose luspatercept (0.6-1.25 mg/kg): 31 NTD and 32 TD patients. Design: The study was a phase 2, noncontrolled, open-label trial comprising a dose-finding base phase and a 5-year extension phase. Methods: Endpoints include safety; erythroid response over a continuous 12-week period [NTD: hemoglobin increase from baseline ⩾1.0 or ⩾1.5 g/dl; TD: red blood cell (RBC) transfusion burden reduction, ⩾20%, ⩾33%, or ⩾50%]; and changes in biomarkers of ineffective erythropoiesis, iron metabolism parameters, Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F) scores, and 6-min walking distance. Results: Median duration of luspatercept exposure for NTD and TD patients was 910 days (range, 40-1850) and 433 days (range, 21-1790), respectively. Seventeen of 31 (54.8%) NTD patients achieved a mean hemoglobin increase of ⩾1.5 g/dl and 19 of 32 (59.4%) TD patients achieved ⩾50% reduction in RBC transfusion burden, during any continuous 12-week period. Median cumulative duration of response was 1126 days (range, 127-1790) for NTD patients and 909 days (range, 87-1734) for TD patients. The most common treatment-related adverse events of any grade were bone pain, headache, and myalgia. Conclusion: Long-term assessment of patients with ß-thalassemia showed luspatercept was associated with sustained increases in hemoglobin levels in NTD patients and sustained transfusion burden reductions in TD patients. Trial registration: (ClinicalTrials.gov Identifiers: NCT01749540 and NCT02268409). Plain Language Summary: Long-term safety and erythroid response with luspatercept treatment in patients with ß-thalassemia Background: ß-thalassemia is a genetic blood disorder caused by mutations in the ß-globin gene, which encodes one of the proteins that comprise hemoglobin, a key constituent of red blood cells. Patients with ß-thalassemia experience anemia, the main treatment for which is blood transfusions. Long-term repeated blood transfusions lower patients' quality of life, use hospital resources, and the resulting accumulation of excess iron can cause organ failure and decrease life expectancy. The severity of the anemia experienced by patients with ß-thalassemia varies; patients with transfusion-dependent ß-thalassemia require regular blood transfusions, compared with those with nontransfusion-dependent ß-thalassemia who require infrequent transfusions, or even none at all, to manage their symptoms. Luspatercept (Reblozyl®) is an agent that stimulates the production of red blood cells and is used to treat anemia caused by ß-thalassemia. However, the long-term effects of luspatercept treatment on patients with ß-thalassemia are not known.Objective: In this study, we report the long-term safety of luspatercept in 64 adult patients with either transfusion-dependent or nontransfusion-dependent ß-thalassemia, and the long-term efficacy of high-dose luspatercept (0.6-1.25 mg/kg) in a subset of 63 patients.Results: The average time period that patients were treated with luspatercept was 910 days for nontransfusion-dependent ß-thalassemia and 433 days for transfusion-dependent ß-thalassemia. We report that in patients with nontransfusion-dependent ß-thalassemia, luspatercept treatment was associated with sustained increases, just over 3 years, in hemoglobin levels. Likewise, in transfusion-dependent ß-thalassemia, luspatercept treatment was associated with a sustained reduction, 2.5 years, in the amount of blood transfusion required to manage their anemia. Long-term treatment with luspatercept was not associated with any new side effects compared with previous short-term treatment studies. The most common side effects were headache (27 patients), bone pain (20 patients), and muscle pain (14 patients) with more than 90% of these patients experiencing these side effects as mild severity.Conclusion: The results of this study show that in patients with either transfusion-dependent or nontransfusion-dependent ß-thalassemia, luspatercept provides lasting reduction in anemia with mostly mild and predictable side effects.

Combination therapy of deferasirox and deferoxamine shows significant improvements in markers of iron overload in a patient with ß-thalassemia major and severe iron burden.

BACKGROUND: Iron overload is a common complication of patients with ß-thalassemia major (TM). Despite the availability of three iron chelators, deferoxamine (DFO), deferiprone (DFP), and deferasirox (DFX), some patients fail to respond adequately to monotherapy with any of them. We report a case of TM who had refractory severe iron overload and was successfully and safely chelated with the combination of DFX with DFO. CASE REPORT: A 40-year-old male with ß-TM, who had been regularly transfused from the age of 2, had been administered in the past iron chelation with DFO, DFP, and DFX monotherapy, without major improvement on his iron overload status. Liver and cardiac magnetic resonance imaging (MRI) revealed severe iron overload, while serum ferritin was persistently greater than 2500 µg/L. After the patient gave informed consent, he was administered combination therapy of DFX at 30 mg/kg/day for 7 days per week and DFO at 2500 mg/day for 4 days every week and routinely followed up for compliance. RESULTS: Eighteen months later, serum ferritin was reduced to 680 µg/L, while both liver and cardiac MRI T2* values improved, reflecting lower iron overload. The combination regimen was well tolerated and no adverse events were documented. CONCLUSION: This is the first official report of simultaneous daily administration of the two iron chelators DFX and DFO that demonstrates the beneficial effect of the combination on heart and liver hemosiderosis. If our observation is confirmed in more patients, this combination could constitute a useful option in tailoring individual chelation therapy for ß-TM patients with iron overload.

Deferiprone as an oral iron chelator in sickle cell disease.

Iron overload is not uncommon in sickle cell disease (SCD) and requires regular chelation therapy in several instances. The present study evaluates the effect of deferiprone in 15 adult patients with SCD (ten beta(s)/beta(0)thalassemia and five beta(s)/beta(s)) and iron overload. Deferiprone was given at a dose of 75 mg/kg daily for 12 months. The evaluation considered pre- and post-treatment values of serum ferritin, urinary iron excretion, and T2 values of liver and heart obtained by magnetic resonance imaging (MRI). Eleven patients had a liver biopsy prior to starting therapy to evaluate iron concentration (LIC). Twelve patients completed the study with satisfactory compliance. In ten of them (83.3%) the serum ferritin levels decreased significantly at the end of the trial; in eight patients (66.6%) the reduction of serum ferritin was accompanied by a significant increase of their liver T2 values. All patients had a significant increase of urinary iron excretion in response to the drug. Ferritin levels and liver T2 values correlated with liver iron concentration; on the contrary, ferritin levels and liver T2 values failed to show any correlation with heart T2 values. Heart T2 values did not also show any correlation with left ventricular ejection fraction. Deferiprone was well tolerated and did not cause any significant adverse effects. These results suggest that deferiprone may effectively decrease the iron deposition in patients with SCD; moreover, T2 MRI proves to be a reliable and rapid, noninvasive method for assessing the liver iron load in patients with SCD.