Sequential high-dose cytarabine and mitoxantrone (S-HAM) versus standard double induction in acute myeloid leukemia-a phase 3 study

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 (CR_i) 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.

Pretransplant NPM1 MRD levels predict outcome after allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia

The objective was to evaluate the prognostic impact of pre-transplant minimal residual disease (MRD) as determined by real-time quantitative polymerase chain reaction in 67 adult NPM1-mutated acute myeloid leukemia patients receiving allogeneic hematopoietic stem cell transplantation (HSCT). Twenty-eight of the 67 patients had a FLT3-ITD (42%). Median age at transplantation was 54.7 years, median follow-up for survival from time of allografting was 4.9 years. At transplantation, 31 patients were in first, 20 in second complete remission (CR) and 16 had refractory disease (RD). Pre-transplant NPM1 MRD levels were measured in 39 CR patients. Overall survival (OS) for patients transplanted in CR was significantly longer as compared to patients with RD (P=0.004), irrespective of whether the patients were transplanted in first or second CR (P=0.74). There was a highly significant difference in OS after allogeneic HSCT between pre-transplant MRD-positive and MRD-negative patients (estimated 5-year OS rates of 40 vs 89% P=0.007). Multivariable analyses on time to relapse and OS revealed pre-transplant NPM1 MRD levels >1% as an independent prognostic factor for poor survival after allogeneic HSCT, whereas FLT3-ITD had no impact. Notably, outcome of patients with pre-transplant NPM1 MRD positivity >1% was as poor as that of patients transplanted with RD.

Regulation of the T cell receptor-alpha mRNA expression in the human lymphoblastic T cell line CEM

We analyzed the transcriptional events involved in the T cell receptor (TcR)-alpha mRNA expression in a human lymphoblastic T-cell line CEM. CD3-negative and CD3-positive CEM subclones that either lack mature TcR-alpha mRNA or express TcR-alpha mRNA were used. Exposure of the TcR-alpha mRNA negative subclones to phorbol 12-myristate 13-acetate (PMA) was followed by 2- to 3-fold increase of transcription, indicating that PMA acts on a transcriptional level. No increase of transcription was observed after blocking protein synthesis with cycloheximide (CHX) or after sequential stimulation with CHX followed by PMA. On the posttranscriptional level, CHX as well as PMA induced a progressive stabilization of TcR-alpha mRNA in the nuclear compartment, which was independent of ongoing transcription. The half-life of the TcR-alpha mRNA upon stimulation was about 6 hours. The accumulation of mature TcR-alpha mRNA seemed to be controlled by nuclear events on a transcriptional as well as posttranscriptional level. The data imply that alterations of TcR-alpha gene transcription are dependent on protein synthesis. DNA-binding proteins enhance transcription and labile nuclear proteins target TcR-alpha mRNA for rapid turnover.