Purpose Philadelphia chromosome (Ph) -like acute lymphoblastic leukemia (ALL) is a high-risk subtype of childhood ALL characterized by kinase-activating alterations that are amenable to treatment with tyrosine kinase inhibitors. We sought to define the prevalence and genomic landscape of Ph-like ALL in adults and assess response to conventional chemotherapy. Patients and Methods The frequency of Ph-like ALL was assessed by gene expression profiling of 798 patients with B-cell ALL age 21 to 86 years. Event-free survival and overall survival were determined for Ph-like ALL versus non-Ph-like ALL patients. Detailed genomic analysis was performed on 180 of 194 patients with Ph-like ALL. Results Patients with Ph-like ALL accounted for more than 20% of adults with ALL, including 27.9% of young adults (age 21 to 39 years), 20.4% of adults (age 40 to 59 years), and 24.0% of older adults (age 60 to 86 years). Overall, patients with Ph-like ALL had an inferior 5-year event-free survival compared with patients with non-Ph-like ALL (22.5% [95% CI, 14.9% to 29.3%; n = 155] v 49.3% [95% CI, 42.8% to 56.2%; n = 247], respectively; P < .001). We identified kinase-activating alterations in 88% of patients with Ph-like ALL, including CRLF2 rearrangements (51%), ABL class fusions (9.8%), JAK2 or EPOR rearrangements (12.4%), other JAK-STAT sequence mutations (7.2%), other kinase alterations (4.1%), and Ras pathway mutations (3.6%). Eleven new kinase rearrangements were identified, including four involving new kinase or cytokine receptor genes and seven involving new partners for previously identified genes. Conclusion Ph-like ALL is a highly prevalent subtype of ALL in adults and is associated with poor outcome. The diverse range of kinase-activating alterations in Ph-like ALL has important therapeutic implications. Trials comparing the addition of tyrosine kinase inhibitors to conventional therapy are required to evaluate the clinical utility of these agents in the treatment of Ph-like ALL.

Chromosomal rearrangements are initiating events in acute lymphoblastic leukaemia (ALL). Here using RNA sequencing of 560 ALL cases, we identify rearrangements between MEF2D (myocyte enhancer factor 2D) and five genes (BCL9, CSF1R, DAZAP1, HNRNPUL1 and SS18) in 22 B progenitor ALL (B-ALL) cases with a distinct gene expression profile, the most common of which is MEF2D-BCL9. Examination of an extended cohort of 1,164 B-ALL cases identified 30 cases with MEF2D rearrangements, which include an additional fusion partner, FOXJ2; thus, MEF2D-rearranged cases comprise 5.3% of cases lacking recurring alterations. MEF2D-rearranged ALL is characterized by a distinct immunophenotype, DNA copy number alterations at the rearrangement sites, older diagnosis age and poor outcome. The rearrangements result in enhanced MEF2D transcriptional activity, lymphoid transformation, activation of HDAC9 expression and sensitive to histone deacetylase inhibitor treatment. Thus, MEF2D-rearranged ALL represents a distinct form of high-risk leukaemia, for which new therapeutic approaches should be considered.

No abstract

Despite recent advancements, approximately 50% of patients with acute myeloid leukemia (AML) do not respond to induction therapy (primary induction failure, PIF) or relapse after &lt;6 months (early relapse, ER). We have recently shown an association between an immune-infiltrated tumor microenvironment (TME) and resistance to cytarabine-based chemotherapy but responsiveness to flotetuzumab, a bispecific DART® antibody-based molecule to CD3ε and CD123. This study reports the results of a multicenter, open-label, phase 1/2 study of flotetuzumab in adults with relapsed/refractory AML. Eighty-eight AML patients were enrolled, 42 in dose-finding and 46 at the recommended phase 2 dose (RP2D) of 500ng/kg/day. Consistent with flotetuzumab's mode of action, the most frequent adverse events were infusion-related reactions (IRR)/cytokine release syndrome (CRS), the majority as grade 1-2. Stepwise dosing during week 1, pre-treatment dexamethasone, prompt use of tocilizumab and temporary dose reductions/interruptions successfully prevented severe IRR/CRS, resulting in acceptable tolerability. Clinical benefit accrued to PIF/ER AML patients, who showed an immune-infiltrated TME. Among 30 PIF/ER patients treated at the RP2D, the CR/CRh rate was 26.7%, with an overall response rate (CR/CRh/CRi) of 30.0%. In PIF/ER patients who achieved CR/CRh, median OS was 10.2 months (range 1.87-27.27), with 6- and 12-month survival rates of 75% (95%CI, 0.450-1.05) and 50% (95%CI, 0.154-0.846). Bone marrow transcriptomic analysis showed that a parsimonious 10-gene signature predicted complete responses to flotetuzumab (AUROC=0.904 versus 0.672 for the ELN risk classifier). Flotetuzumab represents an innovative experimental approach associated with acceptable safety and encouraging evidence of activity in PIF/ER AML patients. Trial registration number: NCT02152956.

We retrospectively analyzed 65 patients with refractory/relapsed (r/r) ALL who were treated with blinatumomab for predictors of leukemia response as well as clinical patterns of relapse and resistance with particular focus on downregulation of CD19 expression and extramedullary disease (EM-ALL). The complete remission (CR) rate was 51%, and 15 (45%) responders underwent allogeneic hematopoietic cell transplantation (HCT) in CR. High leukemia burden (bone marrow blasts >50%) (P = .02), history of prior EM-ALL (P = .005), and active EM-ALL at the time of initiating blinatumomab (P = .05) predicted lower CR rate. Among refractory cases, 13 (41%) had evidence of EM-ALL progression, and CD19 expression was negative or dim in 18% and 23%, respectively. Among responders, 20 (61%) subsequently relapsed among whom EM-ALL relapse occurred in 8 (40%) patients, and CD19 expression was negative or dim in 35 and 6% of evaluable cases, respectively. Pretreatment moderate/strong CD19 expression (P = .01) and history of prior EM-ALL during ALL course (P = .04) were risk factors for developing EM-ALL at progression/relapse. However, no pretreatment factors predicted progression/relapse with CD19-negative ALL. Overall-survival (OS) and even-free survival were improved for patients underwent allogeneic HCT compared to responders who did not. Furthermore, OS was superior for patients responded to blinatumomab compared to those who did not. Extramedullary and CD19-negative disease are common during blinatumomab failure in r/r ALL. In addition to high leukemia burden, concurrent or prior history EM-ALL were associated with lower response to blinatumomab. Higher CD19 expression as well as prior history of EM-ALL were associated with EM-ALL at the time of blinatumomab failure.

Our dose and schedule of pegaspargase, based on its pharmacokinetics, and our detailed toxicity profile could be applied for safer adaptation of pediatric ALL protocols in adults.

No abstract

SummaryStudies of ethnic disparities in malignancies have revealed variation in clinical outcomes. In multiple myeloma (MM), previous literature has focused only on patients of Caucasian and African-American (AA) descent. We present a Surveillance Epidemiology and End Results (SEER)-based outcome analysis of MM patients from a broader range of ethnicities, representing current United States demographics. The SEER 17 Registry data was utilized to analyse adult MM patients diagnosed since 1992 (n = 37 963), as patients of other ethnicities were not well represented prior to that. Overall survival (OS) and myeloma-specific survival (MSS) were compared across different ethnicities stratified by year of diagnosis, registry identification, age, sex and marital-status. Hispanics had the youngest median age at diagnosis (65 years) and Whites had the oldest (71 years) (P < 0·001). Increased age at diagnosis was an independent predictor of decreased OS and MSS. Asians had the best median OS (2·7 years) and MSS (4·1 years), while Hispanics had the worst median OS (2·4 years). These trends were more pronounced in patients 75 years. Cumulative survival benefit over successive years was largest among Whites (1·3 years) and smallest among Asians (0·5 years). These disparities may be secondary to multifactorial causes that need to be explored and should be considered for optimal triaging of healthcare resources.