Induction Therapy with Idarubicin and Etoposide Combined with Sequential or Concurrent Azacitidine In Patients with High-Risk Acute Myeloid Leukemia: Pilot-Phase of the AMLSG 12-09 Study

Treatment outcome in patients with cytogenetically and/or molecularly defined high-risk acute myeloid leukemia (AML) is dismal with low complete remission (CR) rates after intensive induction therapy and 5-year overall survival of about 25% in patients 60 years and younger and far below 5% in patients above the age of 60 years. In younger patients, allogeneic hematopoietic stem cell transplantation (allo-HSCT) from matched related or unrelated donors results in significantly better clinical outcome especially if patients are transplanted early in first CR (Schlenk et al., J. Clin. Oncol. 2010, in press). Azacitidine is a demethylating agent showing promising results as a single agent in AML patients with bone marrow blast counts between 20 and 30%. Therefore, the randomized AMLSG 12-09 trial will evaluate the combination of idarubicin/etoposide chemotherapy combined with azacitidine instead of cytarabine as compared to induction with idarubicin/etoposide/cytarabine (ICE) in an attempt to increase CR rates in these high-risk patients.

To evaluate feasibility of the investigational induction therapy with idarubicin and etoposide in combination with sequentially or concurrently administered subcutaneous (sc) azacitidine.

Patients were treated according to the investigational treatment schedules of the AMLSG 12-09 protocol. Patients received idarubicin 12 mg/sqm on days 1, 3 and 5 and etoposide 100 mg/sqm on days 1, 2 and 3 (patients above the age of 65 years received idarubicin 12 mg/sqm and etoposide 100 mg/sqm only on days 1 and 3, respectively). Azacitidine 100 mg/sqm sc was added on days -5 to -1 in 7 patients (schedule A), days 1 to 5 in 6 patients (schedule B), and days 4 to 8 in 5 patients (schedule C).

18 patients have been treated (13 males and 5 females). Median age was 62.5 years (range, 28–76). The cytogenetic and molecular risk profile of the 18 AML was as follows: Eight AML had MDS-related cytogenetic changes (WHO 2008) including five exhibiting a complex karyotype and two had 3q abnormalities; three AML had balanced t(v;11q23), and six exhibited a normal karyotype together with triple negative genotype (NPM1-wt, FLT3-wt and CEBPA-wt). In one case, there were no metaphases available, however molecularly NPM1-wt, FLT3-wt, CEBPA-wt, no core binding factor AML, no t(15;17) and or t(9;11) were present. Median WBC was 4.6/nl (range, 0–6-75/nl).

Overall response to induction therapy was CR n=7, partial remission (PR) n=3, refractory disease (RD) n=7 and one patient died during induction therapy (ED). Moreover, two patients with RD achieved CR after additional cycles of single agent azacitidine treatment. Overall response rates (CR and PR) according to treatment schedule were 43% (3/7), 67% (4/6) and 80% (4/5) for schedules A, B and C, respectively. Most common azacitidine-related toxicity was local reactions at injection site not exceeding CTC-grade 2. As expected, fever in neutropenia was the most common severe toxicity (83%). In addition, one patient with history of epilepsy had seizures during induction therapy and one patient with history of Crohn‘s disease had mucositis CTC-grade 3. Allo-HSCT has been performed in three patients and is planned in five. After a median time of 7.5 months, 16 of 18 patients are alive.

Azacitidine administered sc can be given safely either sequentially or concurrently in combination with idarubicine/etoposide induction chemotherapy. Response rate of this high-risk population appears promising and the toxicity profile was favorable. The question which schedule is the most effective will be addressed in the randomized AMLSG trial (NCT01180322)

Stilgenbauer: Amgen: Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Genzyme: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Sanofi Aventis: Research Funding. Döhner: Pfizer: Research Funding. Schlenk: Celgene, Pfizer, Novartis, Cephalon, Amgen: Research Funding.