Abstract
Background: Patients with aplastic anemia (AA) can be effectively treated with bone marrow transplantation or immunosuppressive/immunomodulatory therapy, but many will require repeated blood transfusions to manage symptoms of severe anemia and are subsequently at risk of accumulating excessive body iron. Reduction in iron burden across a range of transfusion-dependent anemias, including AA, has been previously demonstrated with deferasirox (Exjade®). More recently, the EPIC trial enrolled the largest cohort of patients with AA undergoing iron chelation to date. The efficacy and safety of deferasirox in these patients are presented.
Methods: Enrolled patients had transfusion-dependent AA and serum ferritin (SF) levels of □1000 ng/mL, or <1000 ng/mL with a history of multiple transfusions (>20 transfusions or 100 mL/kg of red blood cells) and an R2 MRI-confirmed liver iron concentration (LIC) >2 mg Fe/g dry weight. Deferasirox was administered at an initial dose of 10–30 mg/kg/day depending on transfusion requirements, with dose adjustments in steps of 5–10 mg/kg/day (in the range 0–40 mg/kg/day) based on assessment of SF trends and safety markers indicative of iron toxicity. SF was assessed every 4 weeks and the primary efficacy endpoint was the change at week 52 from baseline. Safety assessments included adverse event (AE) monitoring and assessment of laboratory parameters.
Results: In total, 116 AA patients (67 males, 49 females; mean age 33.3 years) were enrolled. Median baseline SF was 3254.0 ng/mL; patients received a mean of 115.8 mL/kg of blood in the year prior to enrollment. Approximately two-thirds of patients (68.1%) had received no prior chelation therapy. Of those who had, patients received deferoxamine (DFO; n=31, 26.7%) or combination DFO/deferiprone (n=6, 5.2%). After 12 months, median SF decreased significantly by 964.0 ng/mL from baseline median of 3254.0 ng/mL (P=0.0003). This occurred at an average actual deferasirox dose of 17.6±4.8 mg/kg/day. The median change in SF from baseline was –970.0 ng/mL (P<0.0001; 3263.0 ng/mL [baseline]; 0.20 mg/kg/day [mean iron intake]) in patients receiving a mean actual deferasirox dose <20 mg/kg/day (n=75) and −883.8 ng/mL (P=0.27; 3238.0 ng/mL [baseline]; 0.29 mg/kg/day [mean iron intake]) in those receiving 20–<30 mg/kg/day (n=40). Overall, 88 patients (76%) completed the study; reasons for discontinuation included AEs (n=13, 11%), consent withdrawal (n=6, 5%), lost to follow-up (n=1, 1%) and various other reasons (n=3, 3%). In addition, five patients (4%) died during the study (one death related to pneumonia, three due to sepsis and one as a result of hepatic adenoma rupture). No death was suspected by investigators to be treatment related. The most common drug-related AEs (investigator-assessed) were: nausea (n=26, 22%), diarrhea (n=18, 16%), rash (n=13, 11%), vomiting (n=10, 9%), dyspepsia (n=9, 8%), abdominal pain (n=7, 6%), upper abdominal pain (n=7, 6%), and anorexia (n=7, 6%). Most AEs were mild or moderate in severity (>95%). 29 patients (25.0%) had an increase in serum creatinine >33% above baseline and the upper limit of normal (ULN) on two consecutive visits; there were no progressive increases. One patient (0.9%) had an increase in alanine aminotransferase (ALT) that exceeded >10xULN on two consecutive visits; ALT levels were elevated in this patient at baseline.
Conclusions: Over a 1-year treatment period, deferasirox significantly reduced iron burden in transfusion-dependent, iron overloaded patients with AA. Despite the high iron burden, most patients had received no prior chelation therapy, indicating a clear need for iron chelation in this patient population. Overall, deferasirox was generally well tolerated in these AA patients with the majority of AEs being mild to moderate.
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