Encorafenib Plus Cetuximab as a New Standard of Care for Previously Treated BRAF V600E-Mutant Metastatic Colorectal Cancer: Updated Survival Results and Subgroup Analyses from the BEACON Study.

PURPOSE: BEACON CRC evaluated encorafenib plus cetuximab with or without binimetinib versus investigators' choice of irinotecan or FOLFIRI plus cetuximab in patients with BRAFV600E-mutant metastatic colorectal cancer (mCRC), after progression on 1-2 prior regimens. In the previously reported primary analysis, encorafenib, binimetinib plus cetuximab (ENCO/BINI/CETUX; triplet) and encorafenib plus cetuximab (ENCO/CETUX; doublet) regimens improved overall survival (OS) and objective response rate (ORR; by blinded central review) versus standard of care. The purpose of this analysis was to report updated efficacy and safety data. METHODS: In this open-label, phase III trial, 665 patients with BRAF V600E-mutant mCRC were randomly assigned 1:1:1 to receive triplet, doublet, or control. Primary end points were OS and independently reviewed ORR comparing triplet to control. OS for doublet versus control was a key secondary end point. Updated analyses include 6 months of additional follow-up and ORR for all randomized patients. RESULTS: Patients received triplet (n = 224), doublet (n = 220), or control (n = 221). Median OS was 9.3 months (95% CI, 8.2 to 10.8) for triplet and 5.9 months (95% CI, 5.1 to 7.1) for control (hazard ratio [HR], 0.60 [95% CI, 0.47 to 0.75]). Median OS for doublet was 9.3 months (95% CI, 8.0 to 11.3) (HR v control, 0.61 [95% CI, 0.48 to 0.77]). Confirmed ORR was 26.8% (95% CI, 21.1% to 33.1%) for triplet, 19.5% (95% CI, 14.5% to 25.4%) for doublet, and 1.8% (95% CI, 0.5% to 4.6%) for control. Adverse events were consistent with the prior primary analysis, with grade ≥ 3 adverse events in 65.8%, 57.4%, and 64.2% for triplet, doublet, and control, respectively. CONCLUSION: In the BEACON CRC study, encorafenib plus cetuximab improved OS, ORR, and progression-free survival in previously treated patients in the metastatic setting compared with standard chemotherapy. Based on the primary and updated analyses, encorafenib plus cetuximab is a new standard care regimen for previously treated patients with BRAF V600E mCRC.

Encorafenib, Binimetinib, and Cetuximab in BRAF V600E-Mutated Colorectal Cancer.

BACKGROUND: Patients with metastatic colorectal cancer with the BRAF V600E mutation have a poor prognosis, with a median overall survival of 4 to 6 months after failure of initial therapy. Inhibition of BRAF alone has limited activity because of pathway reactivation through epidermal growth factor receptor signaling. METHODS: In this open-label, phase 3 trial, we enrolled 665 patients with BRAF V600E-mutated metastatic colorectal cancer who had had disease progression after one or two previous regimens. Patients were randomly assigned in a 1:1:1 ratio to receive encorafenib, binimetinib, and cetuximab (triplet-therapy group); encorafenib and cetuximab (doublet-therapy group); or the investigators' choice of either cetuximab and irinotecan or cetuximab and FOLFIRI (folinic acid, fluorouracil, and irinotecan) (control group). The primary end points were overall survival and objective response rate in the triplet-therapy group as compared with the control group. A secondary end point was overall survival in the doublet-therapy group as compared with the control group. We report here the results of a prespecified interim analysis. RESULTS: The median overall survival was 9.0 months in the triplet-therapy group and 5.4 months in the control group (hazard ratio for death, 0.52; 95% confidence interval [CI], 0.39 to 0.70; P<0.001). The confirmed response rate was 26% (95% CI, 18 to 35) in the triplet-therapy group and 2% (95% CI, 0 to 7) in the control group (P<0.001). The median overall survival in the doublet-therapy group was 8.4 months (hazard ratio for death vs. control, 0.60; 95% CI, 0.45 to 0.79; P<0.001). Adverse events of grade 3 or higher occurred in 58% of patients in the triplet-therapy group, in 50% in the doublet-therapy group, and in 61% in the control group. CONCLUSIONS: A combination of encorafenib, cetuximab, and binimetinib resulted in significantly longer overall survival and a higher response rate than standard therapy in patients with metastatic colorectal cancer with the BRAF V600E mutation. (Funded by Array BioPharma and others; BEACON CRC ClinicalTrials.gov number, NCT02928224; EudraCT number, 2015-005805-35.).

Binimetinib, Encorafenib, and Cetuximab Triplet Therapy for Patients With BRAF V600E-Mutant Metastatic Colorectal Cancer: Safety Lead-In Results From the Phase III BEACON Colorectal Cancer Study.

PURPOSE: To determine the safety and preliminary efficacy of selective combination targeted therapy for BRAF V600E-mutant metastatic colorectal cancer (mCRC) in the safety lead-in phase of the open-label, randomized, three-arm, phase III BEACON Colorectal Cancer trial ( ClinicalTrials.gov identifier: NCT02928224; European Union Clinical Trials Register identifier: EudraCT2015-005805-35). PATIENTS AND METHODS: Before initiation of the randomized portion of the BEACON Colorectal Cancer trial, 30 patients with BRAF V600E-mutant mCRC who had experienced treatment failure with one or two prior regimens were to be recruited to a safety lead-in of encorafenib 300 mg daily, binimetinib 45 mg twice daily, plus standard weekly cetuximab. The primary end point was safety, including the incidence of dose-limiting toxicities. Efficacy end points included overall response rate, progression-free survival, and overall survival. RESULTS: Among the 30 treated patients, dose-limiting toxicities occurred in five patients and included serous retinopathy (n = 2), reversible decreased left ventricular ejection fraction (n = 1), and cetuximab-related infusion reactions (n = 2). The most common grade 3 or 4 adverse events were fatigue (13%), anemia (10%), increased creatine phosphokinase (10%), increased AST (10%), and urinary tract infections (10%). In 29 patients with BRAF V600E-mutant tumors (one patient had a non-BRAF V600E-mutant tumor and was not included in the efficacy analysis), the confirmed overall response rate was 48% (95% CI, 29.4% to 67.5%), median progression-free survival was 8.0 months (95% CI, 5.6 to 9.3 months), and median overall survival was 15.3 months (95% CI, 9.6 months to not reached), with median duration of follow-up of 18.2 months (range, 16.6 to 19.8 months). CONCLUSION: In the safety lead-in, the safety and tolerability of the encorafenib, binimetinib, and cetuximab regimen is manageable and acceptable for initiation of the randomized portion of the study. The observed efficacy is promising compared with available therapies and, if confirmed in the randomized portion of the trial, could establish this regimen as a new standard of care for previously treated BRAF V600E-mutant mCRC.

MicroRNA Profiling of Salivary Duct Carcinoma Versus Her2/Neu Overexpressing Breast Carcinoma Identify miR-10a as a Putative Breast Related Oncogene.

Salivary duct carcinomas (SDC) and Her2/Neu3-overexpressing invasive breast carcinomas (HNPIBC/IBC) are histologically indistinguishable. We investigated whether common histopathologic and immunophenotypic features of SDC and IBC are mirrored by a similar microRNA (miRNA) profile. MiRNA profiling of 5 SDCs, 6 IBCs Her2/Neu3+, and 5 high-grade ductal breast carcinoma in situ (DCIS) was performed by NanoString platform. Selected miRNAs and HOXA1 gene were validated by RT-PCR. We observed similar miRNA expression profiles between IBC and SDC with the exception of 2 miRNAs, miR-10a and miR-142-3p, which were higher in IBC tumors. DCIS tumors displayed increased expression of miR-10a, miR-99a, miR-331-3p and miR-335, and decreased expression of miR-15a, miR-16 and miR-19b compared to SDC. The normal salivary gland and breast tissues also showed similar expression profiles. Interestingly, miR-10a was selectively increased in both IBC and normal breast tissue compared to SDC and normal salivary gland tissue. Moreover, our NanoString and RT-PCR data confirmed that miR-10a was upregulated in IBC and DCIS compared to SDC. Finally, we show downregulation of HOXA1, a miR-10 target, in IBC tumors compared to normal breast tissue. Taken together, our data demonstrates that, based on miRNA profiling, SDC is closely related to HNPIBC. Our results also suggest that miR-10a is differentially expressed in IBC compared to SDC and may have potential utility as a diagnostic biomarker in synchronous or metachronous malignant epithelial malignancies involving both organs. In addition, miR-10a could be playing an important role as a mammary-specific oncogene, involved in breast cancer initiation (DCIS) and progression (IBC), through mechanisms that include modulation of HOXA1 gene expression.

A Phase Ib Dose-Escalation Study of Encorafenib and Cetuximab with or without Alpelisib in Metastatic BRAF-Mutant Colorectal Cancer.

Preclinical evidence suggests that concomitant BRAF and EGFR inhibition leads to sustained suppression of MAPK signaling and suppressed tumor growth in BRAFV600E colorectal cancer models. Patients with refractory BRAFV600-mutant metastatic CRC (mCRC) were treated with a selective RAF kinase inhibitor (encorafenib) plus a monoclonal antibody targeting EGFR (cetuximab), with (n = 28) or without (n = 26) a PI3Kα inhibitor (alpelisib). The primary objective was to determine the maximum tolerated dose (MTD) or a recommended phase II dose. Dose-limiting toxicities were reported in 3 patients receiving dual treatment and 2 patients receiving triple treatment. The MTD was not reached for either group and the phase II doses were selected as 200 mg encorafenib (both groups) and 300 mg alpelisib. Combinations of cetuximab and encorafenib showed promising clinical activity and tolerability in patients with BRAF-mutant mCRC; confirmed overall response rates of 19% and 18% were observed and median progression-free survival was 3.7 and 4.2 months for the dual- and triple-therapy groups, respectively.Significance: Herein, we demonstrate that dual- (encorafenib plus cetuximab) and triple- (encorafenib plus cetuximab and alpelisib) combination treatments are tolerable and provide promising clinical activity in the difficult-to-treat patient population with BRAF-mutant mCRC. Cancer Discov; 7(6); 610-9. ©2017 AACR.See related commentary by Sundar et al., p. 558This article is highlighted in the In This Issue feature, p. 539.

Methylation-dependent loss of RIP3 expression in cancer represses programmed necrosis in response to chemotherapeutics.

Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is an essential part of the cellular machinery that executes "programmed" or "regulated" necrosis. Here we show that programmed necrosis is activated in response to many chemotherapeutic agents and contributes to chemotherapy-induced cell death. However, we show that RIP3 expression is often silenced in cancer cells due to genomic methylation near its transcriptional start site, thus RIP3-dependent activation of MLKL and downstream programmed necrosis during chemotherapeutic death is largely repressed. Nevertheless, treatment with hypomethylating agents restores RIP3 expression, and thereby promotes sensitivity to chemotherapeutics in a RIP3-dependent manner. RIP3 expression is reduced in tumors compared to normal tissue in 85% of breast cancer patients, suggesting that RIP3 deficiency is positively selected during tumor growth/development. Since hypomethylating agents are reasonably well-tolerated in patients, we propose that RIP3-deficient cancer patients may benefit from receiving hypomethylating agents to induce RIP3 expression prior to treatment with conventional chemotherapeutics.

Pluripotent stem cell miRNAs and metastasis in invasive breast cancer.

BACKGROUND: The purpose of this study is to determine whether microRNA for pluripotent stem cells are also expressed in breast cancer and are associated with metastasis and outcome. METHODS: We studied global microRNA profiles during differentiation of human embryonic stem cells (n =26) and in breast cancer patients (n = 33) and human cell lines (n = 35). Using in situ hybridization, we then investigated MIR302 expression in 318 untreated breast cancer patients (test cohort, n = 22 and validation cohort, n = 296). In parallel, using next-generation sequencing data from breast cancer patients (n = 684), we assessed microRNA association with stem cell markers. All statistical tests were two-sided. RESULTS: In healthy tissues, the MIR302 (high)/MIR203 (low) asymmetry was exclusive for pluripotent stem cells. MIR302 was expressed in a small population of cancer cells within invasive ductal carcinoma, but not in normal breast (P < .001). Furthermore, MIR302 was expressed in the tumor cells together with stem cell markers, such as CD44 and BMI1. Conversely, MIR203 expression in 684 breast tumors negatively correlated with CD44 (Spearman correlation, Rho = -0.08, P = .04) and BMI1 (Rho = -0.11, P = .004), but positively correlated with differentiation marker CD24 (Rho = 0.15, P < .001). Primary tumors with lymph node metastasis had cancer cells showing scattered expression of MIR302 and widespread repression of MIR203. Finally, overall survival was statistically significantly shorter in patients with MIR302-positive cancer cells (P = .03). CONCLUSIONS: In healthy tissues the MIR302(high)/MIR203(low) asymmetry was characteristic of embryonic and induced pluripotency. In invasive ductal carcinoma, the MIR302/MIR203 asymmetry was associated with stem cell markers, metastasis, and shorter survival.

Combined molecular and clinical prognostic index for relapse and survival in cytogenetically normal acute myeloid leukemia.

PURPOSE: Cytogenetically normal (CN) acute myeloid leukemia (AML) is the largest and most heterogeneous cytogenetic AML subgroup. For the practicing clinician, it is difficult to summarize the prognostic information of the growing number of clinical and molecular markers. Our purpose was to develop a widely applicable prognostic model by combining well-established pretreatment patient and disease characteristics. PATIENTS AND METHODS: Two prognostic indices for CN-AML (PINA), one regarding overall survival (OS; PINAOS) and the other regarding relapse-free survival (RFS; PINARFS), were derived from data of 572 patients with CN-AML treated within the AML Cooperative Group 99 study (www.aml-score.org). RESULTS: On the basis of age (median, 60 years; range, 17 to 85 years), performance status, WBC count, and mutation status of NPM1, CEBPA, and FLT3-internal tandem duplication, patients were classified into the following three risk groups according to PINAOS and PINARFS: 29% of all patients and 32% of 381 responding patients had low-risk disease (5-year OS, 74%; 5-year RFS, 55%); 56% of all patients and 39% of responding patients had intermediate-risk disease (5-year OS, 28%; 5-year RFS, 27%), and 15% of all patients and 29% of responding patients had high-risk disease (5-year OS, 3%; 5-year RFS, 5%), respectively. PINAOS and PINARFS stratified outcome within European LeukemiaNet genetic groups. Both indices were confirmed on independent data from Cancer and Leukemia Group B/Alliance trials. CONCLUSION: We have developed and validated, to our knowledge, the first prognostic indices specifically designed for adult patients of all ages with CN-AML that combine well-established molecular and clinical variables and that are easily applicable in routine clinical care. The integration of both clinical and molecular markers could provide a basis for individualized patient care through risk-adapted therapy of CN-AML.

SPARC promotes leukemic cell growth and predicts acute myeloid leukemia outcome.

Aberrant expression of the secreted protein, acidic, cysteine-rich (osteonectin) (SPARC) gene, which encodes a matricellular protein that participates in normal tissue remodeling, is associated with a variety of diseases including cancer, but the contribution of SPARC to malignant growth remains controversial. We previously reported that SPARC was among the most upregulated genes in cytogenetically normal acute myeloid leukemia (CN-AML) patients with gene-expression profiles predictive of unfavorable outcome, such as mutations in isocitrate dehydrogenase 2 (IDH2-R172) and overexpression of the oncogenes brain and acute leukemia, cytoplasmic (BAALC) and v-ets erythroblastosis virus E26 oncogene homolog (ERG). In contrast, SPARC was downregulated in CN-AML patients harboring mutations in nucleophosmin (NPM1) that are associated with favorable prognosis. Based on these observations, we hypothesized that SPARC expression is clinically relevant in AML. Here, we found that SPARC overexpression is associated with adverse outcome in CN-AML patients and promotes aggressive leukemia growth in murine models of AML. In leukemia cells, SPARC expression was mediated by the SP1/NF-κB transactivation complex. Furthermore, secreted SPARC activated the integrin-linked kinase/AKT (ILK/AKT) pathway, likely via integrin interaction, and subsequent ß-catenin signaling, which is involved in leukemia cell self-renewal. Pharmacologic inhibition of the SP1/NF-κB complex resulted in SPARC downregulation and leukemia growth inhibition. Together, our data indicate that evaluation of SPARC expression has prognosticative value and SPARC is a potential therapeutic target for AML.

Recombinant interleukin-2 in patients aged younger than 60 years with acute myeloid leukemia in first complete remission: results from Cancer and Leukemia Group B 19808.

BACKGROUND: Recombinant interleukin-2 (rIL-2) induces cellular cytotoxicity against leukemia blasts. Patients with acute myeloid leukemia (AML) in first complete remission (CR) may harbor minimal residual disease that is susceptible to rIL-2-activated effector cells. METHODS: In the Cancer and Leukemia Group B (CALGB) 19808 study, patients with AML in first CR were randomly assigned after all planned chemotherapy to receive a 90-day course of subcutaneously administered rIL-2 or no further therapy. The primary objective was to compare disease-free survival (DFS) between the 2 treatment arms. A total of 534 patients achieved a CR, 214 of whom were randomized. Six courses of low-dose daily rIL-2 were given for the expansion of cytotoxic effector cells, each followed by 3-day high-dose boluses given to trigger cytotoxicity against minimal residual disease. RESULTS: On the protocol-specified intention-to-treat analysis, the hazards ratio for DFS was 0.75 (95% confidence interval, 0.52-1.09; P = .13); the 5-year DFS rate was 42% in the observation arm and 53% in the rIL-2 treatment arm. The hazards ratio for overall survival (OS) was 0.88 (95% confidence interval, 0.54-1.23; P = .34); the 5-year OS rate was 58% for the observation arm and 63% for the rIL-2 treatment arm. Twenty-five of the 107 patients randomized to treatment with rIL-2 either refused or were unable to initiate therapy and 30 patients did not complete their assigned therapy. However, significant toxicities were not commonly observed. The trial design did not anticipate the difficulties patients would encounter with protocol compliance. CONCLUSIONS: The efficacy of immunotherapy with rIL-2 administered after intensive postremission treatment was not assessed as planned because of unexpected refusals by patients and/or their physicians to comply with protocol-directed therapy. Neither DFS nor OS was found to be significantly improved.

Epigenetics meets genetics in acute myeloid leukemia: clinical impact of a novel seven-gene score.

PURPOSE: Molecular risk stratification of acute myeloid leukemia (AML) is largely based on genetic markers. However, epigenetic changes, including DNA methylation, deregulate gene expression and may also have prognostic impact. We evaluated the clinical relevance of integrating DNA methylation and genetic information in AML. METHODS: Next-generation sequencing analysis of methylated DNA identified differentially methylated regions (DMRs) associated with prognostic mutations in older (≥ 60 years) cytogenetically normal (CN) patients with AML (n = 134). Genes with promoter DMRs and expression levels significantly associated with outcome were used to compute a prognostic gene expression weighted summary score that was tested and validated in four independent patient sets (n = 355). RESULTS: In the training set, we identified seven genes (CD34, RHOC, SCRN1, F2RL1, FAM92A1, MIR155HG, and VWA8) with promoter DMRs and expression associated with overall survival (OS; P ≤ .001). Each gene had high DMR methylation and lower expression, which were associated with better outcome. A weighted summary expression score of the seven gene expression levels was computed. A low score was associated with a higher complete remission (CR) rate and longer disease-free survival and OS (P < .001 for all end points). This was validated in multivariable models and in two younger (< 60 years) and two older independent sets of patients with CN-AML. Considering the seven genes individually, the fewer the genes with high expression, the better the outcome. Younger and older patients with no genes or one gene with high expression had the best outcomes (CR rate, 94% and 87%, respectively; 3-year OS, 80% and 42%, respectively). CONCLUSION: A seven-gene score encompassing epigenetic and genetic prognostic information identifies novel AML subsets that are meaningful for treatment guidance.

GAS6 expression identifies high-risk adult AML patients: potential implications for therapy.

Emerging data demonstrate important roles for the TYRO3/AXL/MERTK receptor tyrosine kinase (TAM RTK) family in diverse cancers. We investigated the prognostic relevance of GAS6 expression, encoding the common TAM RTK ligand, in 270 adults (n=71 aged<60 years; n=199 aged ⩾60 years) with de novo cytogenetically normal acute myeloid leukemia (CN-AML). Patients expressing GAS6 (GAS6+), especially those aged ⩾60 years, more often failed to achieve a complete remission (CR). In all patients, GAS6+ patients had shorter disease-free (DFS) and overall (OS) survival than patients without GAS6 expression (GAS6-). After adjusting for other prognostic markers, GAS6+ predicted CR failure (P=0.02), shorter DFS (P=0.004) and OS (P=0.04). To gain further biological insights, we derived a GAS6-associated gene-expression signature (P<0.001) that in GAS6+ patients included overexpressed BAALC and MN1, known to confer adverse prognosis in CN-AML, and overexpressed CXCL12, encoding stromal cell-derived factor, and its receptor genes, chemokine (C-X-C motif) receptor 4 (CXCR4) and CXCR7. This study reports for the first time that GAS6 expression is an adverse prognostic marker in CN-AML. Although GAS6 decoy receptors are not yet available in the clinic for GAS6+ CN-AML therapy, potential alternative therapies targeting GAS6+-associated pathways, for example, CXCR4 antagonists, may be considered for GAS6+ patients to sensitize them to chemotherapy.

Clinical role of microRNAs in cytogenetically normal acute myeloid leukemia: miR-155 upregulation independently identifies high-risk patients.

PURPOSE: To evaluate the impact of miR-155 on the outcome of adults with cytogenetically normal (CN) acute myeloid leukemia (AML) in the context of other clinical and molecular prognosticators and to gain insight into the leukemogenic role of this microRNA. PATIENTS AND METHODS: We evaluated 363 patients with primary CN-AML. miR-155 levels were measured in pretreatment marrow and blood by NanoString nCounter assays that quantified the expression of the encoding gene MIR155HG. All molecular prognosticators were assessed centrally. miR-155-associated gene and microRNA expression profiles were derived using microarrays. RESULTS: Considering all patients, high miR-155 expression was associated with a lower complete remission (CR) rate (P < .001) and shorter disease-free survival (P = .001) and overall survival (OS; P < .001) after adjusting for age. In multivariable analyses, high miR-155 expression remained an independent predictor for a lower CR rate (P = .007) and shorter OS (P < .001). High miR-155 expressers had approximately 50% reduction in the odds of achieving CR and 60% increase in the risk of death compared with low miR-155 expressers. Although high miR-155 expression was not associated with a distinct microRNA expression profile, it was associated with a gene expression profile enriched for genes involved in cellular mechanisms deregulated in AML (eg, apoptosis, nuclear factor-κB activation, and inflammation), thereby supporting a pivotal and unique role of this microRNA in myeloid leukemogenesis. CONCLUSION: miR-155 expression levels are associated with clinical outcome independently of other strong clinical and molecular predictors. The availability of emerging compounds with antagonistic activity to microRNAs in the clinic provides the opportunity for future therapeutic targeting of miR-155 in AML.

Identification of a 24-gene prognostic signature that improves the European LeukemiaNet risk classification of acute myeloid leukemia: an international collaborative study.

PURPOSE: To identify a robust prognostic gene expression signature as an independent predictor of survival of patients with acute myeloid leukemia (AML) and use it to improve established risk classification. PATIENTS AND METHODS: Four independent sets totaling 499 patients with AML carrying various cytogenetic and molecular abnormalities were used as training sets. Two independent patient sets composed of 825 patients were used as validation sets. Notably, patients from different sets were treated with different protocols, and their gene expression profiles were derived using different microarray platforms. Cox regression and Kaplan-Meier methods were used for survival analyses. RESULTS: A prognostic signature composed of 24 genes was derived from a meta-analysis of Cox regression values of each gene across the four training sets. In multivariable models, a higher sum value of the 24-gene signature was an independent predictor of shorter overall (OS) and event-free survival (EFS) in both training and validation sets (P < .01). Moreover, this signature could substantially improve the European LeukemiaNet (ELN) risk classification of AML, and patients in three new risk groups classified by the integrated risk classification showed significantly (P < .001) distinct OS and EFS. CONCLUSION: Despite different treatment protocols applied to patients and use of different microarray platforms for expression profiling, a common prognostic gene signature was identified as an independent predictor of survival of patients with AML. The integrated risk classification incorporating this gene signature provides a better framework for risk stratification and outcome prediction than the ELN classification.

inv(16)/t(16;16) acute myeloid leukemia with non-type A CBFB-MYH11 fusions associate with distinct clinical and genetic features and lack KIT mutations.

The inv(16)(p13q22)/t(16;16)(p13;q22) in acute myeloid leukemia results in multiple CBFB-MYH11 fusion transcripts, with type A being most frequent. The biologic and prognostic implications of different fusions are unclear. We analyzed CBFB-MYH11 fusion types in 208 inv(16)/t(16;16) patients with de novo disease, and compared clinical and cytogenetic features and the KIT mutation status between type A (n = 182; 87%) and non-type A (n = 26; 13%) patients. At diagnosis, non-type A patients had lower white blood counts (P = .007), and more often trisomies of chromosomes 8 (P = .01) and 21 (P < .001) and less often trisomy 22 (P = .02). No patient with non-type A fusion carried a KIT mutation, whereas 27% of type A patients did (P = .002). Among the latter, KIT mutations conferred adverse prognosis; clinical outcomes of non-type A and type A patients with wild-type KIT were similar. We also derived a fusion-type-associated global gene-expression profile. Gene Ontology analysis of the differentially expressed genes revealed-among others-an enrichment of up-regulated genes involved in activation of caspase activity, cell differentiation and cell cycle control in non-type A patients. We conclude that non-type A fusions associate with distinct clinical and genetic features, including lack of KIT mutations, and a unique gene-expression profile.

Lenalidomide-mediated enhanced translation of C/EBPα-p30 protein up-regulates expression of the antileukemic microRNA-181a in acute myeloid leukemia.

Recently, we showed that increased miR-181a expression was associated with improved outcomes in cytogenetically normal acute myeloid leukemia (CN-AML). Interestingly, miR-181a expression was increased in CN-AML patients harboring CEBPA mutations, which are usually biallelic and associate with better prognosis. CEBPA encodes the C/EBPα transcription factor. We demonstrate here that the presence of N-terminal CEBPA mutations and miR-181a expression are linked. Indeed, the truncated C/EBPα-p30 isoform, which is produced from the N-terminal mutant CEBPA gene or from the differential translation of wild-type CEBPA mRNA and is commonly believed to have no transactivation activity, binds to the miR-181a-1 promoter and up-regulates the microRNA expression. Furthermore, we show that lenalidomide, a drug approved for myelodysplastic syndromes and multiple myeloma, enhances translation of the C/EBPα-p30 isoform, resulting in higher miR-181a levels. In xenograft mouse models, ectopic miR-181a expression inhibits tumor growth. Similarly, lenalidomide exhibits antitumorigenic activity paralleled by increased miR-181a expression. This regulatory pathway may explain an increased sensitivity to apoptosis-inducing chemotherapy in subsets of AML patients. Altogether, our data provide a potential explanation for the improved clinical outcomes observed in CEBPA-mutated CN-AML patients, and suggest that lenalidomide treatment enhancing the C/EBPα-p30 protein levels and in turn miR-181a may sensitize AML blasts to chemotherapy.

Prognostic significance of the European LeukemiaNet standardized system for reporting cytogenetic and molecular alterations in adults with acute myeloid leukemia.

PURPOSE: To evaluate the prognostic significance of the international European LeukemiaNet (ELN) guidelines for reporting genetic alterations in acute myeloid leukemia (AML). PATIENTS AND METHODS: We analyzed 1,550 adults with primary AML, treated on Cancer and Leukemia Group B first-line trials, who had pretreatment cytogenetics and, for cytogenetically normal patients, mutational status of NPM1, CEBPA, and FLT3 available. We compared complete remission (CR) rates, disease-free survival (DFS), and overall survival (OS) among patients classified into the four ELN genetic groups (favorable, intermediate-I, intermediate-II, adverse) separately for 818 younger (age < 60 years) and 732 older (age ≥ 60 years) patients. RESULTS: The percentages of younger versus older patients in the favorable (41% v 20%; P < .001), intermediate-II (19% v 30%; P < .001), and adverse (22% v 31%; P < .001) genetic groups differed. The favorable group had the best and the adverse group the worst CR rates, DFS, and OS in both age groups. Both intermediate groups had significantly worse outcomes than the favorable but better than the adverse group. Intermediate-I and intermediate-II groups in older patients had similar outcomes, whereas the intermediate-II group in younger patients had better OS but not better CR rates or DFS than the intermediate-I group. The prognostic significance of ELN classification was confirmed by multivariable analyses. For each ELN group, older patients had worse outcomes than younger patients. CONCLUSION: The ELN classification clearly separates the genetic groups by outcome, supporting its use for risk stratification in clinical trials. Because they have different proportions of genetic alterations and outcomes, younger and older patients should be reported separately when using the ELN classification.