Phase II dosing study of cytarabine chemotherapy in combination with cenersen (EL625) and idarubicin in refractory and relapsed acute myelogenous leukemia (AML)

Abstract

7070 Background: Cenersen is an antisense oligonucleotide that blocks production of p53. It sensitizes acute myeloid leukemia (AML) stem cells in vitro to DNA damage. Methods: Thirty-seven patients (13 refractory, 24 relapsed) with AML have been enrolled in the ongoing trial. All patients received cenersen (0.1 mg/kg/hr continuous intravenous infusion over 4 days [d]) plus Idarubicin (12mg/m2/dx3). Cytarabine was administered as follows: group (1) no cytarabine; (2) 100mg/m2/dx7; (3) 1g/m2/dx4 (3d > 60y). Chemotherapy started day 2. Results: Eighteen patients were treated per protocol and 19 were inevaluable to include 16 who received prohibited substances that block the action of cenersen (acetaminophen and/or high dose antioxidants). Six (33%) of those treated per protocol achieved CR compared to none of the 16 who received prohibited substances (p=0.02). This rate compares favorably to a literature report of a similar patient population (14%; Estey 1996). There were 2 patients who achieved a CRp, one of whom received acetaminophen on day 7. No significant differences in response occurred between the three treatment arms. The remission duration for 7 of the 8 responding patients was longer than the prior remission duration for the same patients. Several adverse events (AEs) (infection, bleeding, mucositis and hair loss) were significantly (p<0.001) less common for patients in this trial compared to the AE frequency described in the package insert for Idarubicin for its use in combination with standard dose Cytarabine. No adverse events attributable to cenersen were identified. Conclusions: We conclude that cenersen in combination with chemotherapy may improve the response rate compared to that expected with chemotherapy alone. No significant financial relationships to disclose.