Arsenic trioxide as primary treatment in acute promyelocytic leukemia

Abstract

16533 Acute Promyelocytic Leukemia (APL) is a separate, distinct and biologically unique subset of Acute Myelogenous Leukemia (AML). The affordability of ATRA is detrimental for its use especially in the developing world. The use of Arsenic trioxide (As2O3) has radically changed the treatment, initially for relapsed APL and now is being used upfront as first line therapy in APL some studies. We accrued 11 cases (6 males, 5 females) of APL for the past 1 year. 2 patients of these had been already treated with ATRA + chemotherapy (Daunorubicin and Cytosine Arabanoside). These relapsed patients were switched over to Arsenic trioxide. One of these relapsed patients has completed the treatment and is in CR for the past 6 months after completing treatment. The other patient has recently completed the treatment and is in remission. 9 of our patients are newly diagnosed and could not afford ATRA and chemotherapy. All these patients were explained the treatment protocol and after obtaining a formal consent, patients were put on Arsenic trioxide. The protocol consists of Induction therapy with Arsenic trioxide given in a dose of 0.15 mg/kg/day till CR is achieved or to a maximum of 60 doses, followed by Consolidation treatment with Arsenic trioxide in the similar dose schedule but only for 28 days, and finally Maintenance therapy with Arsenic trioxide every 10 days a month for a total of 6 months with an interval of 4–6 weeks in between the cycles. Of the remaining patients (n = 7), 2 patients did not respond to Arsenic trioxide after 60 doses. The remaining patients (n = 5) are in different phases of treatment (all having completed Induction therapy) and are presently in CR (Mean duration to avhieve CR-57 days, documented by bone marrow examination). There were no major morbidities and none of our patients exhibited APL syndrome. The lower cost of treatment with Arsenic trioxide (Approx. Rs. 50–60,000) compared to ATRA + chemotherapy (Approx. Rs. 90,000–1,10,000), the magnitude of response and the least encountered adverse effects seem awesome in this treatment especially in the developing countries. No significant financial relationships to disclose.