Core-binding factor leukemia hijacks the T-cell-prone PU.1 antisense promoter.

The blood system serves as a key model for cell differentiation and cancer. It is orchestrated by precise spatiotemporal expression of crucial transcription factors. One of the key master regulators in the hematopoietic systems is PU.1. Reduced levels of PU.1 are characteristic for human acute myeloid leukemia (AML) and are known to induce AML in mouse models. Here, we show that transcriptional downregulation of PU.1 is an active process involving an alternative promoter in intron 3 that is induced by RUNX transcription factors driving noncoding antisense transcription. Core-binding factor (CBF) fusions RUNX1-ETO and CBFß-MYH11 in t(8;21) and inv(16) AML, respectively, activate the PU.1 antisense promoter that results in a shift from sense toward antisense transcription and myeloid differentiation blockade. In patients with CBF-AML, we found that an elevated antisense/sense transcript and promoter accessibility ratio represents a hallmark compared with normal karyotype AML or healthy CD34+ cells. Competitive interaction of an enhancer with the proximal or the antisense promoter forms a binary on/off switch for either myeloid or T-cell development. Leukemic CBF fusions thus use a physiological mechanism used by T cells to decrease sense transcription. Our study is the first example of a sense/antisense promoter competition as a crucial functional switch for gene expression perturbation by oncogenes. Hence, this disease mechanism reveals a previously unknown Achilles heel for future precise therapeutic targeting of oncogene-induced chromatin remodeling.

Talazoparib versus chemotherapy in patients with germline BRCA1/2-mutated HER2-negative advanced breast cancer: final overall survival results from the EMBRACA trial.

BACKGROUND: In EMBRACA, talazoparib prolonged progression-free survival versus chemotherapy (hazard ratio [HR] 0.542 [95% confidence interval (CI) 0.413-0.711]; P < 0.0001) and improved patient-reported outcomes (PRO) in germline BRCA1/2 (gBRCA1/2)-mutated advanced breast cancer (ABC). We report final overall survival (OS). PATIENTS AND METHODS: This randomized phase III trial enrolled patients with gBRCA1/2-mutated HER2-negative ABC. Patients received talazoparib or physician's choice of chemotherapy. OS was analyzed using stratified HR and log-rank test and prespecified rank-preserving structural failure time model to account for subsequent treatments. RESULTS: A total of 431 patients were entered in a randomized study (287 talazoparib/144 chemotherapy) with 412 patients treated (286 talazoparib/126 chemotherapy). By 30 September 2019, 216 deaths (75.3%) occurred for talazoparib and 108 (75.0%) chemotherapy; median follow-up was 44.9 and 36.8 months, respectively. HR for OS with talazoparib versus chemotherapy was 0.848 (95% CI 0.670-1.073; P = 0.17); median (95% CI) 19.3 months (16.6-22.5 months) versus 19.5 months (17.4-22.4 months). Kaplan-Meier survival percentages (95% CI) for talazoparib versus chemotherapy: month 12, 71% (66% to 76%)/74% (66% to 81%); month 24, 42% (36% to 47%)/38% (30% to 47%); month 36, 27% (22% to 33%)/21% (14% to 29%). Most patients received subsequent treatments: for talazoparib and chemotherapy, 46.3%/41.7% received platinum and 4.5%/32.6% received a poly(ADP-ribose) polymerase (PARP) inhibitor, respectively. Adjusting for subsequent PARP and/or platinum use, HR for OS was 0.756 (95% bootstrap CI 0.503-1.029). Grade 3-4 adverse events occurred in 69.6% (talazoparib) and 64.3% (chemotherapy) patients, consistent with previous reports. Extended follow-up showed significant overall improvement and delay in time to definitive clinically meaningful deterioration in global health status/quality of life and breast symptoms favoring talazoparib versus chemotherapy (P < 0.01 for all), consistent with initial analyses. CONCLUSIONS: In gBRCA1/2-mutated HER2-negative ABC, talazoparib did not significantly improve OS over chemotherapy; subsequent treatments may have impacted analysis. Safety was consistent with previous observations. PRO continued to favor talazoparib.

Azacitidine and donor lymphocyte infusions as first salvage therapy for relapse of AML or MDS after allogeneic stem cell transplantation.

The combination of azacitidine and donor lymphocyte infusions (DLI) as first salvage therapy for relapse after allogeneic transplantation (allo-HSCT) was studied in 30 patients with acute myeloid leukemia (AML; n=28) or myelodysplastic syndromes (MDS; n=2) within a prospective single-arm multicenter phase-II trial. Treatment schedule contained up to eight cycles azacitidine (100 mg/m(2)/day, days 1-5, every 28 days) followed by DLI (from 1-5 × 10(6) to 1-5 × 10(8) CD3(+)cells/kg) after every second azacitidine cycle. A median of three courses azacitidine (range 1-8) were administered, and 22 patients (73%) received DLI. Overall response rate was 30%, including seven complete remissions (CRs, 23%) and two partial remissions (7%). Five patients remain in CR for a median of 777 days (range 461-888). Patients with MDS or AML with myelodysplasia-related changes were more likely to respond (P=0.011), and a lower blast count (P=0.039) as well as high-risk cytogenetics (P=0.035) correlated with the likelihood to achieve CR. Incidence of acute and chronic graft-versus-host disease was 37% and 17%, respectively. Neutropenia and thrombocytopenia grade III/IV occurred during 65% and 63% of treatment cycles, while infections were the most common grade III/IV non-hematological toxicity. Azacitidine and DLI as salvage therapy is safe, induces long-term remissions and may become an alternative for patients with AML or MDS relapsing after allo-HSCT.

Tacrolimus and mycofenolate mofetil as GvHD prophylaxis following nonmyeloablative conditioning and unrelated hematopoietic SCT for adult patients with advanced hematologic diseases.

In the current study, we evaluated a combination of tacrolimus and mycophenolate mofetil (MMF) as GvHD prophylaxis in 50 patients undergoing truly nonmyeloablative (NM; 90 mg/m(2) fludarabine, 2 Gy TBI) hematopoietic SCT (HSCT) from unrelated donors. Median patient age was 51 years (range, 25-67 years). After a median follow-up of 1123 days (range, 47-2729 days), 20 patients (40%) are alive and free from disease. The probabilities of 1-, 2- and 3-year survival were 57, 47 and 39%, respectively. Patients who achieved a remission before HSCT had a significantly better OS compared with those who had active disease (P=0.01). The incidences of grade II-IV and III-IV acute GvHD (aGvHD) were 54% (n=27) and 16% (n=8). Remarkably, using tacrolimus and MMF, the median onset of aGvHD occurred distinctly late on day +66 (range, 12-119 days). A total of 46 patients were evaluable for chronic GvHD (cGvHD). Out of these, 26 (56%) patients developed cGvHD, with 16 (34%) of them showing limited and 10 (21%) showing extensive disease. We conclude that the combination of tacrolimus and MMF as post transplant immunosuppression for patients receiving NM unrelated donor HSCT permits stable engraftment and effective prophylaxis for acute and cGvHD. In particular, the occurrence of severe early-onset aGvHD was attenuated.

A 3-day short course of palifermin before HDT reduces toxicity and need for supportive care after autologous blood stem-cell transplantation in patients with multiple myeloma.

BACKGROUND: We retrospectively determined whether a 3-day short course of palifermin could reduce the toxicity of high-dose therapy (HDT) and autologous blood stem-cell transplantation (ASCT) in patients with multiple myeloma (MM). PATIENTS AND METHODS: Sixty-seven consecutive patients received 60 mug/kg palifermin for 3 days before HDT with melphalan 200 or 140 mg/m(2) for patients with renal failure (group A). Granulocyte colony-stimulating factor (G-CSF) was applied after ASCT. Data on haematopoietic reconstitution and toxicity were compared with two previously published patient groups from our institution who had received pegfilgrastim but not palifermin (group B, n = 21) and patients who had received neither palifermin nor G-CSF (group C, n = 21). RESULTS: In group A, patients with renal failure had a significantly higher risk for severe mucositis (64% versus 16%, P < 0.002). Patients with normal renal function who received palifermin experienced significantly less days of hospitalisation (P < 0.05) and less need for narcotic analgesia (P < 0.05), parenteral nutrition (P < 0.05) and erythrocyte transfusions (P < 0.05) in comparison with groups B and C. Time to haematopoietic reconstitution was not compromised by the use of palifermin. CONCLUSIONS: In conclusion, a short 3-day course of palifermin may be able to reduce the toxicity of HDT and ASCT in patients with MM. Patients with impaired renal function at the time of HDT need additional strategies to further reduce the incidence of severe mucositis.

Bendamustine in patients with relapsed or refractory multiple myeloma.

OBJECTIVE: In patients with multiple myeloma, bendamustine monotherapy is effective as 1st and 2nd line therapy. However, data for patients with advanced multiple myeloma is rare. METHODS: In this retrospective analysis we have identified 39 patients with relapsed or refractory multiple myeloma by means of case research, who have been treated at our institution with bendamustine as salvage therapy. After in median 2 lines of prior therapy (range: 1-5) patients received in median 3 (range: 1-10) cycles of bendamustine. Bendamustine dosage was 80-150 mg on day 1+2 of a monthly cycle. Bendamustine was administered as monotherapy in 39% of patients, whereas 61% received concomitant steroids. RESULTS: Toxicity was mild to moderate. Response rates were as follows: 3% vgPR, 33% PR, 18% MR, 26% SD and 20% PD. The median event-free and overall survival were 7 and 17 months, respectively. CONCLUSIONS: In conclusion, in patients with advanced multiple myeloma bendamustine is effective and associated with mild toxicity. Therefore, the role of bendamustine in patients with multiple myeloma should be investigated in further clinical trials.

5-Azacytidine for the treatment of patients with acute myeloid leukemia or myelodysplastic syndrome who relapse after allo-SCT: a retrospective analysis.

Patients with AML or myelodysplastic syndrome who relapse after allo-SCT have a poor prognosis. In the search for novel treatment strategies for these patients, we conducted a multicenter retrospective analysis and identified 22 patients treated with the DNA-methylation inhibitor 5-azacytidine (5-Aza). Patients received a median number of two cycles 5-Aza (range 1-8) at a dose of 100 mg/m(2) over 5 days following relapse. Eighteen patients (82%) also received a median number of two donor lymphocyte infusions (DLI, range 1-5). Sixteen patients (72%) responded to 5-Aza treatment and five patients (23%) achieved a CR. 5-Aza-induced CR lasted for 433 days (median, range 114-769). Median survival and the estimated 2-year survival rate were 144 days and 23%, respectively. Acute GVHD after DLI was seen in six patients (33%) and four of these patients developed chronic GVHD of the skin. There were no treatment-related deaths. Patients who achieved halving of leukocyte counts after the first 5-Aza cycle had a superior median survival of 802 days compared with 135 days (P=0.0025) in all other patients. On univariate analysis, the achievement of this halving of leukocyte counts was identified as a significant predictor of survival.

Fludarabine, amsacrine, high-dose cytarabine and 12 Gy total body irradiation followed by allogeneic hematopoietic stem cell transplantation is effective in patients with relapsed or high-risk acute lymphoblastic leukemia.

In this prospective study, we examined the toxicity and efficacy of an intensified conditioning regimen for treatment of patients with relapsed or high-risk acute lymphoblastic leukemia who undergo allogeneic hematopoietic stem cell transplantation. Fifteen patients received fludarabine 30 mg/m(2), cytarabine 2000 mg/m(2), amsacrine 100 mg/m(2) on days -10, -9, -8 and -7, anti-thymocyte globulin (ATG-Fresenius) 20 mg/kg body weight on days -6, -5 and -4 and fractionated total body irradiation 2 x 2 Gy on days -3, -2 and -1 (FLAMSA-ATG-TBI) before allogeneic hematopoietic stem cell transplantation. At the time of hematopoietic stem cell transplantation, 10 patients were in complete remission (8 CR1; 2 CR2), 3 with primary refractory and 2 suffered from refractory relapse. All patients achieved a complete remission after hematopoietic stem cell transplantation; and after a median follow-up time of 1091 days (range, 334-1554 days), nine patients (60%) are alive and free from disease, including three patients with prior refractory disease. Three patients died due to treatment-related mortality. The most frequent and severe conditioning-related toxicities observed in 9 out of 15 patients were grade III/IV infections according to common toxicity criteria. Thus, conditioning with the FLAMSA-ATG-TBI regimen is a feasible and effective alternative for patients with relapsed or high-risk acute lymphoblastic leukemia.

Pegfilgrastim for PBSC mobilization and autologous haematopoietic SCT.

To date, G-CSF is the most favoured cytokine administered for PBSC mobilization because of its great efficacy and lack of serious toxicity. Recently, a pegylated filgrastim (pegfilgrastim) has been introduced. Attachment of the polyethylene glycol (PEG) moiety reduces renal excretion and masks proteolytic cleavage sites resulting in elevated G-CSF serum levels for up to 14 days after a single injection. As single-dose pegfilgrastim had similar effects in the prophylaxis of chemotherapy-induced neutropenia as the daily administration of the unconjugated drug, its capability for the mobilization of haematopoietic stem and progenitor cells has been assessed and presented to be at least equal to that of conventional G-CSF. Administration of pegfilgrastim following high-dose therapy and autologous blood SCT (BSCT) shortened the time to myeloid recovery as seen in conventional G-CSF. Plasma G-CSF levels were about 1 log higher with pegfilgrastim, but in the setting of autologous BSCT this did not translate into a faster haematopoietic recovery. Only few data exist on the biological effects of pegfilgrastim. Still, these data suggest that pegfilgrastim-stimulation results in different functional properties of haematopoietic stem and progenitor cells compared with G-CSF.

The hematopoietic stem cell in chronic phase CML is characterized by a transcriptional profile resembling normal myeloid progenitor cells and reflecting loss of quiescence.

We found that composition of cell subsets within the CD34+ cell population is markedly altered in chronic phase (CP) chronic myeloid leukemia (CML). Specifically, proportions and absolute cell counts of common myeloid progenitors (CMP) and megakaryocyte-erythrocyte progenitors (MEP) are significantly greater in comparison to normal bone marrow whereas absolute numbers of hematopoietic stem cells (HSC) are equal. To understand the basis for this, we performed gene expression profiling (Affymetrix HU-133A 2.0) of the distinct CD34+ cell subsets from six patients with CP CML and five healthy donors. Euclidean distance analysis revealed a remarkable transcriptional similarity between the CML patients' HSC and normal progenitors, especially CMP. CP CML HSC were transcriptionally more similar to their progeny than normal HSC to theirs, suggesting a more mature phenotype. Hence, the greatest differences between CP CML patients and normal donors were apparent in HSC including downregulation of genes encoding adhesion molecules, transcription factors, regulators of stem-cell fate and inhibitors of cell proliferation in CP CML. Impaired adhesive and migratory capacities were functionally corroborated by fibronectin detachment analysis and transwell assays, respectively. Based on our findings we propose a loss of quiescence of the CML HSC on detachment from the niche leading to expansion of myeloid progenitors.

Sorafenib (Nexavar) induces molecular remission and regression of extramedullary disease in a patient with FLT3-ITD+ acute myeloid leukemia.

The fms-related tyrosine kinase 3 internal tandem duplication (FLT3-ITD) can be found in about one quarter of patients with acute myeloid leukemia (AML) [Small D. FLT3 mutations: biology and treatment. Hematology Am Soc Hematology. Educ. Program 2006;178-84 [Review]]. Patients who carry this mutation have a high risk of relapse even after allogeneic stem cell transplantation [Sheikhha MH, Awan A, Tobal K, Liu Yin JA. Prognostic significance of FLT3 ITD and D835 mutations in AML patients. Hematol J 2003;4:41-6; Meshinchi S, Arceci RJ, Sanders JE, Smith FO, Woods WB, Radich JP, et al. Role of allogeneic stem cell transplantation in FLT3/ITD-positive AML. Blood 2006;108(1):400-1]. Recent reports show that Sorafenib, a multikinase inhibitor has significant activity against FLT3-ITD(+) blasts in vitro [Auclair D, Miller D, Yatsula V, Pickett W, Carter C, Chang Y, et al. Antitumor activity of sorafenib in FLT3-driven leukemic cells. Leukemia 2007;21(3):439-45]. We here report the first clinical case of molecular remission induced by Sorafenib in a patient with FLT3-ITD(+) AML and extramedullary disease after allogenic stem cell transplantation.