The Safety, Tolerability and Efficacy of Deferasirox in Older Patients with Transfusional Dependent Anemia

Background

The majority of myelodysplastic syndrome (MDS), primary myelofibrosis (MPN) and aplastic anemia (AA) patients during the course of the disease develops a symptomatic anemia requiring transfusions of packed red blood cells (PRBC), each of them containing approximately 200 mg of elementary iron. Because of the fact that human beings are unable to actively eliminate iron from the body, secondary emosiderosis yet becomes evident when body iron content is above 7-14 grams, an amount easily reached after receiving as few as 15-30 PRCB units.From a pathophysiologic point of view, long-term transfusion therapy is certainly the most important cause of iron overload (IOL) in these patients; nevertheless, others mechanism account for this phenomenon, and in particular the role of the ineffective erythropoiesis.Deferasirox (DSX) is the principal option currently available for iron chelation therapy in the management of IOL due to transfusion dependent anemia. DSX is also a potent NF-kB inhibitor, and this effect may explain in part the phenomenon of hematological improvements reported in different clinical trials and in case reports.

Materials and Methods

We analyzed 21 patients,16 male and 5 female, with transfusion dependent anemia and with a transfusional history of almost 10 packed PRBC, treated with DSX from 1 February 2013 to 1 February 2014. Median age was 80 years (65-88). 20 patients (95%) have almost a comorbidity, 7 of them (30%) have more than 3 comorbidities. Heart disease was the most common comorbidity. At baseline median creatinine clearance was 76 ml/min; in 12 patients was < 60ml/min but >40 ml/min, according to NCCN Guidelines. All patients (16 MDS, 3 MPN, 1 AA, 1 hemolytic anemia) were evaluated for IOL by serum ferritin (SF), while only 7 with RM T2*.Median SF at baseline was 1750 μg/L and median PRBC was 32.The starting dose of DSX was 10 mg/kg/day; the dosage should be adjusted up to 20–30 mg/kg/daily according to the transfusional regimen, SF and IOL, if tolerated.

Objectives

To observe safety, tolerability, and efficacy of iron chelation therapy with DSX in older patients with transfusion dependent anemia.

Results

The SF decreased of 50% and 66% after 3 and 6 months respectively. The SF was normalized (SF<500 μg/L) in 5 patients (24%) after six months. The IOL occurred also in patients with a short transfusional history, inferior to 10 packed red blood cells, and SF <1000 μg/L. That was more evident in MDS patients especially in RARS. The median dose tolerated of DSX was 20 mg/kg/daily.The drug related adverse events (AE) was evaluated by the Common Terminology Criteria for Adverse Events (CTCAE versione 4.02). The severe adverse events (SAE) occurred in 10%.The most Common AE were diarrhea, nausea, upper abdominal pain, serum creatinine increase and rash. Hematologic response according to IWG criteria 2006 with DSX were observed in 17% of patients and was more frequent in MPN than MDS, independently from IOL.

Conclusion

DSX has shown high efficacy in a variety of iron overloaded patients with different anemias. Appropriate patient selection and regular clinical multidisciplinary evaluation of comorbidity and concomitant therapy remains a critical components of successful ther­apy, combined with carefull monitoring for both adverse effects and clinical efficacy, in order to derive the most benefit from a carefully imple­mented chelation strategy.In our cohort improvement of erythropoiesis was marginal. This might be due to the very small patient group analyzed.