These results suggest that NOD2 mutations have influence on the occurrence of acute GVHD after transplantation.

Dose-dense induction with the S-HAM regimen was compared to standard double induction therapy in adult patients with newly diagnosed acute myeloid leukemia. Patients were centrally randomized (1:1) between S-HAM (2nd chemotherapy cycle starting on day 8 = “dose-dense”) and double induction with TAD-HAM or HAM(-HAM) (2nd cycle starting on day 21 = “standard”). 387 evaluable patients were randomly assigned to S-HAM (N = 203) and to standard double induction (N = 184). The primary endpoint overall response rate (ORR) consisting of complete remission (CR) and incomplete remission (CRi) was not significantly different (P = 0.202) between S-HAM (77%) and double induction (72%). The median overall survival was 35 months after S-HAM and 25 months after double induction (P = 0.323). Duration of critical leukopenia was significantly reduced after S-HAM (median 29 days) versus double induction (median 44 days)—P < 0.001. This translated into a significantly shortened duration of hospitalization after S-HAM (median 37 days) as compared to standard induction (median 49 days)—P < 0.001. In conclusion, dose-dense induction therapy with the S-HAM regimen shows favorable trends but no significant differences in ORR and OS compared to standard double induction. S-HAM significantly shortens critical leukopenia and the duration of hospitalization by 2 weeks.

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Background For curative treatment of younger patients with acute myeloid leukemia (AML) double induction with two cycles of intensive cytarabine/ anthracycline based chemotherapy 21 days apart is the current standard of care. In the prospective randomized AML-CG 2008 trial we asked question whether current results could be improved on by a dose-dense regimen (S-HAM – Sequential High-dose cytArabine and Mitoxantrone) in which the interval between cycles was minimized to 3 days. A prior large one-armed study (AML-CG 2004) had demonstrated a high antileukemic efficacy and shortened neutropenia of the S-HAM regimen as compared to a historical control of standard double induction treatment. The first clinical results of the randomized comparison are presented here. Methods All patients with first diagnosis of a de-novo or secondary AML (excluding APL) that were deemed fit for intensive induction chemotherapy by their treating physician were eligible for this study. Younger patients in the standard arm were treated with one cycle of TAD-9 (standard dose cytarabine and daunorubicine 60mg/m2 for 3 days) and a mandatory second cycle of HAM (high dose cytarabine and mitoxantrone) starting at day 21. Elderly patients were treated with one cycle of HAM followed by a second cycle of HAM only in case of residual leukemia in the day 16 bone marrow aspirate. Patients in the experimental arm all received S-HAM (two sequential cycles of high-dose cytarabine on days 1+2, mitoxantrone days 3+4) with a 3 days interval. Patients in the age cohort 60 – 69 could be allocated to the “younger” or “elderly” cohort according to their biological fitness at the discretion of the treating physician. However high-dose cytarabine dosages were allocated according to chronological age with patients <60 years receiving 3g/m2 cytarabine per dose and patients 60+ years receiving 1g/m2. The primary endpoint was the overall response rate (i.e. CR + CRirate), secondary endpoints were duration of critical neutropenia, overall survival amongst others. Postremission treatment consisted of recommended early allogeneic transplantation in high risk patients and conventional postremission treatment according to the AML-CG standard (one cycle of TAD-9 consolidation followed by up to 3 years of maintenance treatment) in patients with low risk disease. Results 396 patients were randomized into the study with an age range of 18 to 86 years (median 58). The 387 evaluable patients (184 standard, 203 experimental) were well balanced according to their clinical characteristics, cytogenetics, molecular genetics and overall risk profile. For the primary endpoint a higher ORR of 77% for S-HAM could be found as compared to 72% in the standard arm which was however not significant because a 15% difference had been postulated for the study. Non-hematological toxicities did not show any significant differences. However this was in clear contrast to hematological toxicities: Importantly the duration of critical neutropenia was highly significantly reduced by more than 2 weeks from 45 days (standard) to 29 days (S-HAM) counted from day 1 of treatment. Similarly critical thrombocytopenia was reduced by 13 days from 46 days to 33 days. The early death (ED) rate between both arms was identical between both arms. However a subgroup analysis demonstrated a significantly reduced ED rate in patients receiving 1g/m2 S-HAM as compared to all other treatment groups. The respective ED rates for the various time intervals (always counted from day d1 of treatment) for the 1g/m2S-HAM group were as follows: Interval d1-14 1%, d1-30 3%, d1-60 5%, d1-90 10%. Data for overall survival will be available in November 2013. Conclusion The dose-dense induction regimen S-HAM was highly feasible in patients up to the 8th age decade. The antileukemic efficacy was high with an ORR of 77% for the whole group of unselected patients. As compared to standard double induction dose-dense S-HAM reduced critical neutropenia by more than two weeks. Moreover the subgroup of patients receiving the 1g/m2 S-HAM regimen experienced the lowest ED rate ever reported in the AML-CG trials. This underlines that in contrast to our general expectations the concept of dose-density is able to combine high antileukemic efficacy with significantly reduced haematological toxicity in AML, characterising this approach as first candidate for the next standard arm for future trials of the study group. Disclosures: Lengfelder: TEVA/ Cephalon: Research Funding.

The innate immune system detects invading pathogens through several pattern-recognition receptors and represents the first line of mucosal host defense. Mutations of the NOD2/CARD15 and Toll like receptor −2, −4, −9 genes have been associated with an increased incidence of inflammatory bowel disease due to a diminished response to bacterial cell wall products. Moreover, it was reported that mutations of NOD2 gene loci might be associated with an increased risk for TRM and severe GVHD in patients who underwent allogeneic blood stem cell transplantation. Here we analyzed 201 patients and their respective donors for NOD2, TLR-2, TLR-4 and TLR-9 mutations and correlated the results with the incidence of overall acute GVHD and intestinal GVHD. Further, we evaluated if the occurrence of NOD2/CARD15 and TLR allele mutations are accompanied with an increased risk for transplant-related mortality and overall survival. Mutated alleles of the NOD2 gene were observed in 17% of the patients and 16% of the donors. NOD2 gene mutations in patients and donors together were associated with an increased incidence of severe acute GVHD grade III-IV (6/11 patients; 55% versus 35/145 patients; 24%). If a mutated allele of the NOD2 gene was found either in patients or in donors only no correlation with increased incidence of severe acute GVHD was seen in this study. Patients with mutated alleles in TLR-4 genes (Asp299Gly and Thr399Ile) had a higher incidence of intestinal GVHD (p<0.02), whereas mutations of donor alleles only had no influence on the occurrence of intestinal GVHD in this analysis. No correlation with intestinal GVHD or overall acute GVHD was seen in patients with mutated alleles for TLR-2 and TLR-9. Overall survival, TRM and relapse risks was not influenced in none of the patients with mutated alleles of the innate immune system genes. Multivariate analysis including all potential factors, confirmed that that mutations of NOD2/CARD15 in patients and donors together influenced the occurrence of severe acute GVHD, whereas the occurrence of intestinal GVHD was influenced in patients by mutated alleles of TLR-4 gene. But mutations in alleles of the NOD2 or TLR-2,−4,−9 had no influence on the outcome of allogeneic transplant (TRM and overall survival) in the multivariate analysis. Since all patients in our institution had received an intestinal bacterial decontamination using metronidazole and ciprofloxacin after allogeneic stem cell transplantation, it might be speculative, if the reduction of concentrations of anaerobic bacteria in the intestinum might have protected patients from the occurrence of increased TRM. Decontamination of anaerobic bacteria is associated with a reduced risk for severe acute GVHD as reported earlier (Blood1999; 93:3267–75).