Rowe, Jacob M.

Key Points High-dose daunorubicin benefits AML patients with favorable and intermediate cytogenetics and with FLT3-ITD, NPM1, and DNMT3A mutations. High-dose daunorubicin is required for the favorable impact of the NPM1 mutation in AML.

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti‐CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8‐12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m2 weekly)(n = 16) or low dose (20 mg/m2 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression‐free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti‐CD20 mAb therapy as a potentially more effective use of anti‐CD20 mAb in the treatment of CLL. Am. J. Hematol. 91:308–312, 2016. © 2015 Wiley Periodicals, Inc.

SummaryPatients with mantle cell lymphoma (MCL) generally respond to first‐line immunochemotherapy, but often show chemoresistance upon subsequent relapses, with poor outcome. Several studies of the immunomodulator, lenalidomide, have demonstrated its activity in MCL including the MCL‐001 study in relapsed/refractory patients who had failed defined prior therapies of anthracyclines or mitoxantrone, cyclophosphamide, rituximab and also bortezomib. We present here the long‐term efficacy follow‐up of the prospective phase II MCL‐001 study (N = 134), including new exploratory analyses with baseline Ki‐67 (MIB1), a biological marker of tumour proliferation. With longer follow‐up, lenalidomide showed a 28% overall response rate [ORR; 8% complete response (CR)/CR unconfirmed (CRu)]. Median duration of response (DOR), progression‐free survival and overall survival were 16·6, 4·0 and 20·9 months, respectively. Myelosuppression continued to be the most common grade 3/4 toxicity. Several studies of MCL patients treated with chemotherapy, rituximab and bortezomib have shown an inverse association between survival and Ki‐67. Ki‐67 data in 81/134 MCL‐001 patients showed similar ORRs in both low (<30% or <50%) versus high (≥30% or ≥50%) Ki‐67–expressing groups, yet lower Ki‐67 levels demonstrated superior CR/CRu, DOR and survival outcomes. Overall, lenalidomide showed durable efficacy with a consistent safety profile in heavily pretreated, relapsed/refractory MCL post‐bortezomib.

Key PointsIn this first ALL GWAS in AYAs, we determined that inherited GATA3 variants strongly influence ALL susceptibility in this age group. These findings revealed similarities and differences in the genetic basis of ALL susceptibility between young children and AYAs.

Key Points Imatinib improves outcomes for adults with Ph+ ALL at least in part by facilitating allogeneic stem cell transplant. Allogeneic hematopoietic stem cell transplant is not dispensible in Ph+ ALL in the imatinib era.

Key Points Serum 2HG analysis by LC-MS can accurately identify patients with AML with and without IDH mutations. Oncometabolite testing of serum 2HG is indicated as a diagnostic, prognostic, and therapeutic monitoring tool in AML.

Abstract Genetic lesions such as BCR–ABL1, E2A–PBX1, and MLL rearrangements (MLLr) are associated with unfavorable outcomes in adult B-cell precursor acute lymphoblastic leukemia (B-ALL). Leukemia oncoproteins may directly or indirectly disrupt cytosine methylation patterning to mediate the malignant phenotype. We postulated that DNA methylation signatures in these aggressive B-ALLs would point toward disease mechanisms and useful biomarkers and therapeutic targets. We therefore conducted DNA methylation and gene expression profiling on a cohort of 215 adult patients with B-ALL enrolled in a single phase III clinical trial (ECOG E2993) and normal control B cells. In BCR–ABL1-positive B-ALLs, aberrant cytosine methylation patterning centered around a cytokine network defined by hypomethylation and overexpression of IL2RA(CD25). The E2993 trial clinical data showed that CD25 expression was strongly associated with a poor outcome in patients with ALL regardless of BCR–ABL1 status, suggesting CD25 as a novel prognostic biomarker for risk stratification in B-ALLs. In E2A–PBX1-positive B-ALLs, aberrant DNA methylation patterning was strongly associated with direct fusion protein binding as shown by the E2A–PBX1 chromatin immunoprecipitation (ChIP) sequencing (ChIP-seq), suggesting that E2A–PBX1 fusion protein directly remodels the epigenome to impose an aggressive B-ALL phenotype. MLLr B-ALL featured prominent cytosine hypomethylation, which was linked with MLL fusion protein binding, H3K79 dimethylation, and transcriptional upregulation, affecting a set of known and newly identified MLL fusion direct targets with oncogenic activity such as FLT3 and BCL6. Notably, BCL6 blockade or loss of function suppressed proliferation and survival of MLLr leukemia cells, suggesting BCL6-targeted therapy as a new therapeutic strategy for MLLr B-ALLs. Significance: We conducted the first integrative epigenomic study in adult B-ALLs, as a correlative study to the ECOG E2993 phase III clinical trial. This study links for the first time the direct actions of oncogenic fusion proteins with disruption of epigenetic regulation mediated by cytosine methylation. We identify a novel clinically actionable biomarker in B-ALLs: IL2RA(CD25), which is linked with BCR–ABL1 and an inflammatory signaling network associated with chemotherapy resistance. We show that BCL6 is a novel MLL fusion protein target that is required to maintain the proliferation and survival of primary human adult MLLr cells and provide the basis for a clinical trial with BCL6 inhibitors for patients with MLLr. Cancer Discov; 2(11); 1004–23. ©2012 AACR. Read the Commentary on this article by Cimmino and Aifantis, p. 976. This article is highlighted in the In This Issue feature, p. 961

Abstract We determined the prognostic relevance of CD25 (IL-2 receptor-α) expression in 657 patients (≤ 60 years) with de novo acute myeloid leukemia (AML) treated in the Eastern Cooperative Oncology Group trial, E1900. We identified CD25POS myeloblasts in 87 patients (13%), of whom 92% had intermediate-risk cytogenetics. CD25 expression correlated with expression of stem cell antigen CD123. In multivariate analysis, controlled for prognostic baseline characteristics and daunorubicin dose, CD25POS patients had inferior complete remission rates (P = .0005) and overall survival (P < .0001) compared with CD25NEG cases. In a subset of 396 patients, we integrated CD25 expression with somatic mutation status to determine whether CD25 impacted outcome independent of prognostic mutations. CD25 was positively correlated with internal tandem duplications in FLT3 (FLT3-ITD), DNMT3A, and NPM1 mutations. The adverse prognostic impact of FLT3-ITDPOS AML was restricted to CD25POS patients. CD25 expression improved AML prognostication independent of integrated, cytogenetic and mutational data, such that it reallocated 11% of patients with intermediate-risk disease to the unfavorable-risk group. Gene expression analysis revealed that CD25POS status correlated with the expression of previously reported leukemia stem cell signatures. We conclude that CD25POS status provides prognostic relevance in AML independent of known biomarkers and is correlated with stem cell gene-expression signatures associated with adverse outcome in AML.

SummaryAlthough the incidence rate of acute lymphoblastic leukaemia (ALL) is slightly higher in older than in younger adults, response rates to induction chemotherapy and survival rates are poorer. The contribution of disease‐related versus treatment‐related factors remains unclear. We analysed 100 older patients (aged 55–65 years) treated on the UKALLXII/ECOG2993 trial compared with 1814 younger patients (aged 14–54 years). Baseline characteristics, induction chemotherapy course, infections, drug reductions and survival outcomes were compared. There were more Philadelphia‐positive (Ph+) patients in the older group (28% vs. 17%, P = 0·02), and a trend towards higher combined cytogenetic risk score (46% vs. 35%, P = 0·07). The complete remission rate in older patients was worse (73% vs. 93%, P < 0·0001) as was 5‐year overall survival (21% vs. 41%, P < 0·0001) and event‐free survival (EFS) (19% vs. 37%, P < 0·0001). Older patients had more infections during induction (81% vs. 70%, P = 0·05), and drug reductions (46% vs. 28%, P = 0·0009). Among older patients, Ph+ and cytogenetic risk category as well as infection during induction predicted for worse EFS. Poorer outcomes in these patients are partly due to cytogenetic risk, but there is significant morbidity and mortality during induction chemotherapy with frequent delays and drug reductions. New approaches, including better risk stratification and use of targeted therapies, could improve treatment for these patients.

Abstract Chemotherapy-related myeloid neoplasia (t-MN) is a significant late toxicity concern after cancer therapy. In the randomized intergroup phase 3 E2997 trial, initial therapy of chronic lymphocytic leukemia with fludarabine plus cyclophosphamide (FC) compared with fludarabine alone yielded higher complete and overall response rates and longer progression-free, but not overall, survival. Here, we report t-MN incidence in 278 patients enrolled in E2997 with a median 6.4-year follow-up. Thirteen cases (4.7%) of t-MN occurred at a median of 5 years from initial therapy for chronic lymphocytic leukemia, 9 after FC and 4 after fludarabine alone. By cumulative incidence methodology, rates of t-MN at 7 years were 8.2% after FC and 4.6% after fludarabine alone (P = .09). Seven of the 9 cases of t-MN after FC occurred without additional therapy. Abnormalities involving chromosomes 5 or 7 were found in 10 cases, which suggests alkylator involvement. These data suggest that FC may induce more t-MN than fludarabine alone.