Results from a 1-year, open-label, single arm, multi-center trial evaluating the efficacy and safety of oral Deferasirox in patients diagnosed with low and int-1 risk myelodysplastic syndrome (MDS) and transfusion-dependent iron overload

Abstract

The majority of patients with myelodysplastic syndrome (MDS) present with anemia and will become dependent on regular transfusions of packed red blood cells (PRBC) with the risk of iron overload (IOL). Liver iron content best reflects the total body iron content, and measurement of liver iron concentration (LIC) by MRI is a validated tool for detection, but data in MDS is rather limited. Here we present the results of a multi-center trial evaluating the efficacy and safety of deferasirox (DFX) in low and intermediate-1 risk MDS patients with transfusion-dependent IOL. Three patients with transfusion frequency of > 4 units PRBC per month were initially treated with 30mg/kg/day while in 46 patients with a lower transfusion burden deferasirox was initiated at 20mg/kg/day, due to patient related reasons one patient received DFX in a dose of 6mg/kg/day only. LIC was measured by MRI at baseline and end of study using the method by St. Pierre et al. The intention to treat population consisted of 50 MDS patients (28 male; 22 female) with a median age of 69years who were treated with DFX for a median duration of 354days. Mean daily dose of DFX was 19mg/kg/day. Median serum ferritin level (SF) at baseline was 2,447ng/mL and decreased to 1,685ng/mL (reduction by 31%) at end of study (p = 0.01). In 7 (13%) patients the initially chosen dose had to be increased due to unsatisfactory efficacy of chelation therapy. For 21 patients, LIC measurement by liver MRI was performed at baseline and for 19 of these patients at the end of study: mean LIC decreased significantly from 16,8mg/g dry tissue weight (± 8.3mg/g dry tissue weight) at study entry to 10,8mg/g dry tissue weight (± 10.4mg/g dry tissue weight) at end of study (p = 0.01). Of all patients exposed to the study drug (n = 54), 28 (52%) did not complete the 12month study period most commonly due to AEs in 28% (n = 15) and abnormal laboratory values in 7% (n = 4), respectively. The most common adverse events (≥ 10% of all patients) with suspected drug relationship were diarrhea (n = 25, 46%), nausea (n = 13, 24%), upper abdominal pain (n = 8, 15%), serum creatinine increase (n = 16, 30%) and rash (n = 5, 9%). Adverse events making dose adjustments or interruption of study drug necessary occurred in 33 patients (61%). Hematologic improvement according to IWG criteria (2006) was observed in 6 patients (11%). Initiation of treatment of IOL with DFX depending on the transfusion burden yields sufficient reduction of excess iron indicated by serum ferritin levels and most importantly by liver MRI. The safety profile of DFX was comparable to previous observations.