Hematologic Improvement with Iron Chelation using therapy Deferasirox in Patients with Aplastic Anemia: A Subgroup Analysis of KAMS0112 Prospective Study,

Abstract 3424

Patients with aplastic anemia (AA) are suffered from various complications related to bone marrow failure and peripheral cytopenia. Although immunosuppressive therapy or hematopoietic stem cell transplantation has been performed for curative purpose, the majority of patients have been treated only by supportive cares including repeated transfusion. However, because continued transfusion eventually induces iron overload in many tissues and organs, transfusional iron overload and its consequences are another life-threatening problems for AA patients. Previous reports about iron chelation therapy (ICT) have mainly shown its efficiency for decreasing tissue iron and safety. However, improvement in hematopoiesis after iron chelation therapy has been limitedly reported as case reports or trials involving small number of patients without objective tools for measuring tissue iron content. In the KAMS0112 study (a multi-center, open label, prospective study evaluating the efficacy of ICT with deferasirox in transfusional iron overload with myelodysplastic syndrome or AA using quantitative R₂-MRI, Ferriscan), a total of 54 patients with AA showing serum ferritin level over 1,000 ng/ml were enrolled from 19 institutes, and further analyzed for the changes in hemogram during ICT as well as efficacy and safely of deferasirox. During the study, the specific treatments for AA, such as immunosuppressive therapy or hematopoietic stem cells transplantation, were not undertaken. During 1 year prior to study, patients received 23.7±16.9 units of red blood cell (RBC) product, and the baseline serum ferritin level and liver iron content (LIC) were 4,164±447 ng/ml and 20.1±12.0 mg Fe/g DW, respectively. Deferasirox was given orally at a dose of 20 mg/kg/day for at least 6 months to all patients. If the serum ferritin level falls below 500 ng/ml, treatment was withheld. In spite of continued transfusional support during the study, serum ferritin level and LIC were significantly decreased after 1 year of ICT with deferasirox (Ds-ferritin=−3,076.7±489.9 ng/ml, p=0.0003; DLIC=−7.73 mg/Fe/g DW, p=0.001). To evaluate the improvement of each parameter in hemogram by ICT, patients with baseline hemoglobin level less than 8.0 g/dl (n=28), with baseline WBC count less than 4/ml (n=43), and with baseline platelet count less than 20/ml (n=31) were selected separately. At the end of study, hemoglobin level and platelet count (8.2±3.0 g/dl and 22.2±31.4/ml, respectively) was significantly increased from the baseline value (6.1±1.1 g/dl, p=0.001; 12.5±12.4/ml, p=0.05, respectively). WBC count was also slightly increased (from 2.1±0.9/ml to 2.3±0.9/ml, p=0.457). Considering the relatively uniform criteria of transfusion, the finding that hemoglobin level and platelet count could increase above 8 g/dl and 20/ml, respectively, after 1 year of deferasirox treatment is clinically significantly. Due to gradual improvement of anemia, requirement of RBC transfusion had continuously decreased during the study period (R²=0.31). This subanalysis of KAMS0112 study demonstrates that ICT using deferasirox can be effective in improving anemia and thrombocytopenia in the transfusional iron overload patients with AA, as well as reducing serum ferritin level and LIC. Further studies might be required to elucidate the mechanism involved in the improvement of hematopoiesis associated with correction of deranged intracellular iron homeostasis.