Outcome of 421 adult patients with Philadelphia-negative acute lymphoblastic leukemia treated under an intensive program inspired by the GIMEMA LAL1913 clinical trial: a Campus ALL study.

The introduction of pediatric-inspired regimens in adult Philadelphia-negative acute lymphoblastic leukemia (Ph-ALL) has significantly improved patients' prognosis. Within the Campus ALL network we analyzed the outcome of adult Ph-ALL patients treated according to the GIMEMA LAL1913 protocol outside the clinical trial, to compare the real-life data with the study results. We included 421 consecutive patients, with a median age of 42 years. The complete remission (CR) rate after the first course of chemotherapy was 94% and a measurable residual disease (MRD) negativity after the third course was achieved in 72% of patients. The 3-year overall survival (OS) and disease-free survival (DFS) were 67% and 57%, respectively. In a multivariate analysis, MRD positivity negatively influenced DFS. In a time-dependent analysis including only very high risk (VHR) and MRD positive cases, transplanted (HSCT) patients had a significantly better DFS than non-HSCT ones (P=0.0017). During induction, grade ≥2 pegaspargase-related hepato-toxicity was observed in 25% of patients (vs 12% in the GIMEMA LAL1913 trial, P=0.0003). In this large real-life cohort of Ph-ALL, we confirmed the very high CR rate and a superimposable OS and DFS compared to the GIMEMA LAL1913 clinical trial: CR rate after C1 94% vs 85%, P=0.0004; 3-year OS 67% vs 67%, P=0.94; 3-year DFS 57% vs 63%, P=0.17. HSCT confirms its important role in VHR and MRD-positive patients. The rate of pegaspargase-related toxicity was significantly higher in the real-life setting, emphasizing the importance of dose adjustment in the presence of risk factors to avoid excessive toxicity.

Orthogonal proteogenomic analysis identifies the druggable PA2G4-MYC axis in 3q26 AML.

The overexpression of the ecotropic viral integration site-1 gene (EVI1/MECOM) marks the most lethal acute myeloid leukemia (AML) subgroup carrying chromosome 3q26 abnormalities. By taking advantage of the intersectionality of high-throughput cell-based and gene expression screens selective and pan-histone deacetylase inhibitors (HDACis) emerge as potent repressors of EVI1. To understand the mechanism driving on-target anti-leukemia activity of this compound class, here we dissect the expression dynamics of the bone marrow leukemia cells of patients treated with HDACi and reconstitute the EVI1 chromatin-associated co-transcriptional complex merging on the role of proliferation-associated 2G4 (PA2G4) protein. PA2G4 overexpression rescues AML cells from the inhibitory effects of HDACis, while genetic and small molecule inhibition of PA2G4 abrogates EVI1 in 3q26 AML cells, including in patient-derived leukemia xenografts. This study positions PA2G4 at the crosstalk of the EVI1 leukemogenic signal for developing new therapeutics and urges the use of HDACis-based combination therapies in patients with 3q26 AML.

Stem cell architecture drives myelodysplastic syndrome progression and predicts response to venetoclax-based therapy.

Myelodysplastic syndromes (MDS) are heterogeneous neoplastic disorders of hematopoietic stem cells (HSCs). The current standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, almost 50% of MDS patients fail HMA therapy and progress to acute myeloid leukemia, facing a dismal prognosis due to lack of approved second-line treatment options. As cancer stem cells are the seeds of disease progression, we investigated the biological properties of the MDS HSCs that drive disease evolution, seeking to uncover vulnerabilities that could be therapeutically exploited. Through integrative molecular profiling of HSCs and progenitor cells in large patient cohorts, we found that MDS HSCs in two distinct differentiation states are maintained throughout the clinical course of the disease, and expand at progression, depending on recurrent activation of the anti-apoptotic regulator BCL-2 or nuclear factor-kappa B-mediated survival pathways. Pharmacologically inhibiting these pathways depleted MDS HSCs and reduced tumor burden in experimental systems. Further, patients with MDS who progressed after failure to frontline HMA therapy and whose HSCs upregulated BCL-2 achieved improved clinical responses to venetoclax-based therapy in the clinical setting. Overall, our study uncovers that HSC architectures in MDS are potential predictive biomarkers to guide second-line treatments after HMA failure. These findings warrant further investigation of HSC-specific survival pathways to identify new therapeutic targets of clinical potential in MDS.

Nelarabine as salvage therapy and bridge to allogeneic stem cell transplant in 118 adult patients with relapsed/refractory T-cell acute lymphoblastic leukemia/lymphoma. A CAMPUS ALL study.

The outcome of relapsed or refractory (R/R) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) in adults is poor, with less than 20% of patients surviving at 5 years. Nelarabine is the only drug specifically approved for R/R T-ALL/T-LBL, but the information to support its use is based on limited available data. The aim of this observational phase four study was to provide recent additional data on the efficacy and safety of nelarabine in adults with R/R T-ALL/T-LBL and to evaluate the feasibility and outcome of allogeneic hematopoietic stem cell transplant (SCT) after salvage with nelarabine therapy. The primary endpoints were overall response rate (ORR) and overall survival (OS). Additional endpoints were safety, SCT rate and post-SCT OS. Between May 2007 and November 2018, 118 patients received nelarabine salvage therapy at 27 Italian hematology sites. The median age was 37 years (range 18-74 years), 73% were male, 77 had a diagnosis of T-ALL and 41 of T-LBL, and 65/118 (55%) had received more than two lines of therapy. The median number of nelarabine cycles was two (range 1-4); 43/118 (36%) patients had complete remission (CR), 16 had partial remission (14%) and 59 (50%) were refractory, with an ORR of 50%. The probability of OS, from the first dose of nelarabine, was 37% at 1 year with a median survival of 8 months. The OS at 1 year was significantly better for the 47 patients (40%) who underwent SCT after nelarabine salvage therapy (58% vs 22%, log-rank P < .001). The probability of OS at 2 and 5 years from SCT was 46% and 38%, respectively. Seventy-five patients (64%) experienced one or more drug-related adverse events (AE). Grade III-IV neurologic toxicities were observed in 9/118 (8%) of cases and thrombocytopenia or/and neutropenia (grade III-IV) were reported in 41% and 43% of cases, respectively. In conclusion, this is one of the largest cohorts of adult patients with R/R T-ALL/T-LBL treated in real life with nelarabine. Taking into account the poor prognosis of this patient population, nelarabine represents an effective option with an ORR of 50% and a CR rate of 36%. In addition, 40% of cases following nelarabine salvage therapy could undergo SCT with an expected OS at 2 and 5 years of 46% and 38%, respectively. The safety profile of nelarabine was acceptable with only 8% of cases showing grade III-IV neurological AE.

Haploidentical hematopoietic stem cell transplantation in adults using the αßTCR/CD19-based depletion of G-CSF-mobilized peripheral blood progenitor cells.

In patients with hematological malignancies at high risk for relapse, a mismatched hematopoietic stem cells transplants can be offered with no undue delay between decision-making and transplantation as virtually all patients have a full-haplotype mismatched member who could serve immediately as a donor. Using a T-cell depletion approach, these patients can benefit from a graft-vs-leukemia effect in the absence of both acute and chronic graft-vs-host disease. Over the past decade, efforts have concentrated on developing new conditioning regimens, optimizing the graft processing and improving the posttransplant immunological recovery. The innovative strategy based on the selective depletion of alpha/beta-positive T lymphocytes from G-CSF-mobilized peripheral blood precursor cells has shown very promising results in the setting of the pediatric transplantation. This paper reports the outcome in adult patients with hematological malignancies.

Febrile events in acute lymphoblastic leukemia: a prospective observational multicentric SEIFEM study (SEIFEM-2012/B ALL).

The purpose of the present study is to estimate the current incidence of febrile events (FEs) and infectious episodes in acute lymphoblastic leukemia (ALL) and evaluate the outcome. We analyzed data on all FEs in a cohort of patients affected by ALL admitted to 20 Italian hematologic centers during 21 months of observation from April 1, 2012 to December 31, 2013. Data about treatment phase, steroids, neutropenia, type and site of infection, and outcome of infection were collected. The population comprehended 271 ALL adult patients. Median age was 46 years old (range 19-75), M/F 1.1:1. We collected 179 FEs occurring during 395 different phases of treatment in 127 patients (45.3% incidence): remission induction treatment 53.1%, consolidation/maintenance 35.7%, treatment for a first or second relapse 44.3%, and refractory disease 85.7%. The incidence of FUO (fever of unknown origin) was 55/395 (13.9%). In the remaining cases, bacteria caused 92 FEs (23.2%), fungi 17 (4.3%), viruses 5 (1%). Mixed infections occurred in 10 cases mainly fungal+bacterial (9/10 cases). Neutropenia was mostly present at onset of FE (89.9% of FEs). Mortality rate was 11.7% (21/179) while 16 deaths occurred with evidence of infection (8.9%). Age > 60 years, neutropenia, poor performance status, steroids, refractory disease, and mixed infections significantly correlated with infection-related mortality. A statistically significant association with mortality was observed also for pulmonary localization and bacteremia. Our study describes the real-life epidemiological scenario of infections in ALL and identifies a subset of patients who are at higher risk for infection-related mortality.