Daunorubicine, Cytarabine and Cladribine (DAC) Vs Daunorubicine and Cytarabine (DA) Induction Treatment in Elderly Acute Myeloid Leukemia (AML) Patients – Results of the Prospective, Multicenter, Randomized Trial of the Polish Adult Leukemia Group (PALG)

AML in elderly patients is associated with very poor prognosis. The best treatment option for this group of patients is not established, yet. The intensity of treatment depends on performance status and comorbidities. The previous PALG AML study showed that addition of cladribine (2CdA) to conventional induction therapy; especially in patients above 40 yrs, is associated with better outcome (Ho³owiecki 2004). Based on this observation we designed a study addressed to newly diagnosed AML patients above 60 yrs old, who were fit enough to intensive treatment.

To verify whether addition of 2CdA has an impact to clinical outcome in newly diagnosed AML patients older than 60 years old.

From October 2004 to November 2011, 178 patients from 16 hematological PALG centers were randomly assigned to DA induction therapy consisting of daunorubicine (DNR) 45mg/m², intravenously (iv), day 1–3 and cytarabine (AraC) 100 mg/m², iv, day 1–7 (DA) or DA with addition of 2CdA 5mg/m², iv, day 1–5 (DAC). Patients, who achieved complete remission (CR), received one course of consolidation with mitoxantron 6mg/m2 iv day1–2 and AraC 100mg/m² iv day 1–5, followed by six cycles of maintenance consisting of (DNR 30mg/m2 iv day 1–2 with AraC 100mg/m² sc day 1–5 and tioguanine 100mg/m2, p.o., twice day, day 1–5 with AraC 100mg/m² s.c. day 1–5, alternately). Response criteria were determined according to revised recommendations of the International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia (Chesson 2003).

Pairwise comparisons between patient characteristics were performed by the Mann-Whitney U-test for continuous variables and by χ²-statistics or Fisher's exact test for categorical variable. The Kaplan-Meier estimates of survival were calculated and compared using the log-rank test. For multivariate analysis, the Cox proportional hazard regression model was applied. P values < 0.05 were considered significant.

88 pts with median age 66 yrs (range 60–79 yrs) were randomized to DA and 90 pts with median age 64 yrs (range 60–79 yrs) was enrolled to DAC schema. The both groups were comparable in terms of age, sex, performance status, white blood cell count, hemoglobin level, platelets count, tumor burden parameters, cytogenetic, between the both groups. The overall CR rate was 38%. In DA and DAC groups CR was achieved in 33% and 43% pts, respectively (p=0.12). However, in patients under 65 yrs the trend towards higher CR rate in DAC arm than DA group was observed (47% vs. 29%, p=0.09). In pts above 65 yrs the CR rate was comparable (39% vs. 38%, p=0.8). The efficacy and hematological toxicity in DA and DAC groups was similar (Table 1). Also no statistical significant differences in non-hematological toxicity were observed (data not shown). Early deaths in DA and DAC did not differ significantly. Median overall survival (OS) in DA and DAC arm was also similar in both groups (Table 1). In proportional hazard Cox analysis only age under 65yo, CR achievement and WBC above 100G/L were important for better OS (p=0.02, p<0.001 and p=0.09). The presence of dysplastic changes, karyotype, LDH, number of bone marrow blasts did not influenced OS.

Our data suggest that prolonged overall survival can be achieved in elderly AML patients mainly till 65yrs. Intensive therapy, especially in patients older than 65yrs, may be associated with high number of complications what results withdrawing from intensive treatment protocol. Hematological and non-hematological toxicity of DA and DAC schema is comparable, however higher CR rate in DAC group in patient till 65yrs may suggest, that addition of 2CdA to DA does not increase toxicity and may be a treatment option in this patient population.

Wiktor-Jedrzejczak:Janssen-Cilag: Consultancy; Amgen: Consultancy; Novartis: Consultancy, Speakers Bureau; Pfizer: Consultancy; Bayer: Consultancy; Genopharm: Speakers Bureau; Celgene: Speakers Bureau; Genzyme: Speakers Bureau; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.