Multicenter retrospective analysis of clinical outcome of adult patients with mixed-phenotype acute leukemia treated with acute myeloid leukemia-like or acute lymphoblastic leukemia-like chemotherapy and impact of allogeneic stem cell transplantation: a Campus ALL study.

Mixed-phenotype acute leukemia (MPAL) is a rare disease. Treatment is often similar to that of acute lymphoblastic leukemia (ALL), but the outcome in adults and the role of allogeneic stem cell transplantation (AlloSCT) are not well defined. We report on 77 adult patients diagnosed with MPAL over the last 10 years and treated with a curative intent. Median age was 49 years; 7.6% of cases had a BCR::ABL1 rearrangement. Thirty patients (39%) were treated with an acute myeloid leukemia (AML)-like induction and 47 (61%) with an ALL-like scheme. The complete remission (CR) rate was 67.6% and an ALL-like therapy was associated with a better CR rate (P = 0.048). The median OS was 41.9 months; age ≤ 60 years was associated with a better OS (67 vs 26 months, P = 0.014). An AlloSCT was performed in 50 patients (65%). The 5-year OS of transplanted patients was 54%. The OS post-AlloSCT was better in patients who were minimal residual disease (MRD)-negative prior to transplant (75.8% vs 45.2%, P = 0.06). This study shows that MPAL patients respond better to an ALL-like induction therapy; that consolidation therapy should include, whenever possible, an AlloSCT and that MRD negativity should be a primary endpoint of treatment.

Incidence, treatment and outcome of central nervous system relapse in adult acute lymphoblastic leukaemia patients treated front-line with paediatric-inspired regimens: A retrospective multicentre Campus ALL study.

Within the Campus ALL network we analyzed the incidence, characteristics, treatment and outcome of a central nervous system (CNS) relapse in 1035 consecutive adult acute lymphoblastic leukemia (ALL) patients treated frontline with pediatric-inspired protocols between 2009 and 2020. Seventy-one patients (6.8%) experienced a CNS recurrence, more frequently in T- (28/278; 10%) than in B-ALL (43/757; 5.7%) (p = 0.017). An early CNS relapse-< 12 months from diagnosis-was observed in 41 patients. In multivariate analysis, risk factors for early CNS relapse included T-cell phenotype (p = <0.001), hyperleucocytosis >100 × 109 /L (p<0.001) and male gender (p = 0.015). Treatment was heterogeneous, including chemotherapy, radiotherapy, intrathecal therapy and novel agents. A complete remission (CR) was obtained in 39 patients (55%) with no differences among strategies. After CR, 26 patients underwent an allogenic transplant, with a significant overall survival benefit compared to non-transplanted patients (p = 0.012). After a median observation of 8 months from CNS relapse, 23 patients (32%) were alive. In multivariate analysis, the time to CNS relapse was the strongest predictor of a lower 2-year post-relapse survival (p<0.001). In conclusion, in adult ALL the outcome after a CNS relapse remains very poor. Effective CNS prophylaxis remains the best approach and allogenic transplant should be pursued when possible.

Unbalanced IDO1/IDO2 Endothelial Expression and Skewed Keynurenine Pathway in the Pathogenesis of COVID-19 and Post-COVID-19 Pneumonia.

Despite intense investigation, the pathogenesis of COVID-19 and the newly defined long COVID-19 syndrome are not fully understood. Increasing evidence has been provided of metabolic alterations characterizing this group of disorders, with particular relevance of an activated tryptophan/kynurenine pathway as described in this review. Recent histological studies have documented that, in COVID-19 patients, indoleamine 2,3-dioxygenase (IDO) enzymes are differentially expressed in the pulmonary blood vessels, i.e., IDO1 prevails in early/mild pneumonia and in lung tissues from patients suffering from long COVID-19, whereas IDO2 is predominant in severe/fatal cases. We hypothesize that IDO1 is necessary for a correct control of the vascular tone of pulmonary vessels, and its deficiency in COVID-19 might be related to the syndrome's evolution toward vascular dysfunction. The complexity of this scenario is discussed in light of possible therapeutic manipulations of the tryptophan/kynurenine pathway in COVID-19 and post-acute COVID-19 syndromes.

The serological prevalence of SARS-CoV-2 infection in patients with chronic myeloid leukemia is similar to that in the general population.

BACKGROUND: Patients with hematological malignancies are at an increased risk of SARS-CoV-2 disease (COVID-19) and adverse outcome. However, a low mortality rate has been reported in patients with chronic myeloid leukemia (CML). Preclinical evidence suggests that tyrosine kinase inhibitors (TKIs) may have a protective role against severe COVID-19. METHODS: We conducted a cross-sectional study of 564 consecutive patients with CML who were tested for anti-SARS-CoV-2 IgG/IgM antibodies at their first outpatient visit between May and early November 2020 in five hematologic centers representative of three Italian regions. RESULTS: The estimated serological prevalence of SARS-CoV-2 infection in patients with CML after the first pandemic wave was similar to that in the general population (about 2%), both at national and regional levels. CML patients with positive anti-SARS-CoV-2 serology were more frequently male (p = 0.027) and active workers (p = 0.012), while there was no significant association with TKI treatment type. Only 3 out of 11 IgG-positive patients had previously received a molecular diagnosis of COVID-19, while the remainders were asymptomatic or with mild symptoms. CONCLUSIONS: Our data confirm that the course of SARS-CoV-2 infection in patients with CML is generally mild and reassure about the safety of continuing TKIs during the COVID-19 pandemic. Furthermore, we suggest that patients with CML succeed to mount an antibody response after exposure to SARS-CoV-2, similar to the general population.

The pathogenic role of epithelial and endothelial cells in early-phase COVID-19 pneumonia: victims and partners in crime.

Current understanding of the complex pathogenesis of COVID-19 interstitial pneumonia pathogenesis in the light of biopsies carried out in early/moderate phase and histology data obtained at postmortem analysis is discussed. In autopsies the most observed pattern is diffuse alveolar damage with alveolar-epithelial type-II cell hyperplasia, hyaline membranes, and frequent thromboembolic disease. However, these observations cannot explain some clinical, radiological and physiopathological features observed in SARS-CoV-2 interstitial pneumonia, including the occurrence of vascular enlargement on CT and preserved lung compliance in subjects even presenting with or developing respiratory failure. Histological investigation on early-phase pneumonia on perioperative samples and lung biopsies revealed peculiar morphological and morpho-phenotypical changes including hyper-expression of phosphorylated STAT3 and immune checkpoint molecules (PD-L1 and IDO) in alveolar-epithelial and endothelial cells. These features might explain in part these discrepancies.

Covid-19 Interstitial Pneumonia: Histological and Immunohistochemical Features on Cryobiopsies.

BACKGROUND: The pathogenetic steps leading to Covid-19 interstitial pneumonia remain to be clarified. Most postmortem studies to date reveal diffuse alveolar damage as the most relevant histologic pattern. Antemortem lung biopsy may however provide more precise data regarding the earlier stages of the disease, providing a basis for novel treatment approaches. OBJECTIVES: To ascertain the morphological and immunohistochemical features of lung samples obtained in patients with moderate Covid-19 pneumonia. METHODS: Transbronchial lung cryobiopsy was carried out in 12 Covid-19 patients within 20 days of symptom onset. RESULTS: Histopathologic changes included spots of patchy acute lung injury with alveolar type II cell hyperplasia, with no evidence of hyaline membranes. Strong nuclear expression of phosphorylated STAT3 was observed in >50% of AECII. Interalveolar capillaries showed enlarged lumen and were in part arranged in superposed rows. Pulmonary venules were characterized by luminal enlargement, thickened walls, and perivascular CD4+ T-cell infiltration. A strong nuclear expression of phosphorylated STAT3, associated with PD-L1 and IDO expression, was observed in endothelial cells of venules and interstitial capillaries. Alveolar spaces macrophages exhibited a peculiar phenotype (CD68, CD11c, CD14, CD205, CD206, CD123/IL3AR, and PD-L1). CONCLUSIONS: Morphologically distinct features were identified in early stages of Covid-19 pneumonia, with epithelial and endothelial cell abnormalities different from either classical interstitial lung diseases or diffuse alveolar damage. Alveolar type II cell hyperplasia was a prominent event in the majority of cases. Inflammatory cells expressed peculiar phenotypes. No evidence of hyaline membranes and endothelial changes characterized by IDO expression might in part explain the compliance and the characteristic pulmonary vasoplegia observed in less-advanced Covid-19 pneumonia.

Real-World Multicenter Experience in Tumor Debulking Prior to Blinatumomab Administration in Adult Patients With Relapsed/Refractory B-Cell Precursor Acute Lymphoblastic Leukemia.

Blinatumomab is an immunotherapeutic agent with dual specificity for CD3 and CD19 that is approved for the treatment of relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL). A steroid based pre-treatment is recommended before administering blinatumomab to patients with a high tumor burden to minimize the risk of tumor lysis syndrome, but the optimal debulking regimen and whether it can improve responses remain unclear. The present study retrospectively evaluated real-world outcomes following tumor debulking and blinatumomab infusion in R/R B-ALL adult patients treated at 7 Italian centers. Data were collected from 34 patients. The choice of the cytoreductive therapy was made by the treating clinician on an individual patient basis; regimens included chemotherapy (n=23), steroids (n=7) and tyrosine kinase inhibitors alone or in combination (n=4). The rate of complete responses (CR) and complete minimal residual disease (MRD) responses in CR patients were 67.6% and 81% respectively, after 2 cycles of blinatumomab. Moreover, among patients with a high tumor burden 50% obtained a CR, with 89% of them also achieving a complete MRD response. Favorable responses were also obtained in patients over 50 years of age at treatment initiation. Overall, 7 of 23 patients in CR after blinatumomab underwent hematopoietic stem cell transplantation. The results of this retrospective study highlight the heterogeneity in the use of pre-blinatumomab tumor debulking in real-life clinical practice. Nonetheless, debulking pre-treatment enhanced responses to blinatumomab compared to historic studies, indicating that this strategy may help to improve outcomes for R/R B-ALL patients.

Effects of CD20 antibodies and kinase inhibitors on B-cell receptor signalling and survival of chronic lymphocytic leukaemia cells.

Recently, clinical trial results have established inhibitors of B-cell receptor (BCR)-associated kinase (BAKi), with or without CD20 moniclonal antibodies (mAbs), as the preferred first-line treatment for most chronic lymphocytic leukaemia (CLL) patients. Using phosphospecific flow cytometry, we showed that in leukaemic cells from CLL patients the CD20 therapeutic antibodies - rituximab, ofatumumab, and obinutuzumab - inhibited BCR signalling pathways targeting preferentially pBTKY551 - but not BTKY223 - and pAKT. On the contrary, ibrutinib and idelalisib reduced pBTKY223 to a higher extent than pBTKY551 . The strong reduction of pAKT induced by idelalisib was enhanced by its combination with rituximab or ofatumumab. Moreover, CD20 mAbs and BAKi induced the death of leukaemia cells that was significantly potentiated by their combination. Analysis of the enhancement of cell death in these combinations revealed an approximately additive enhancement induced by rituximab or obinutuzumab combined with ibrutinib or idelalisib. Taken together, our data identified negative regulatory effects of CD20 mAbs and their combinations with BAKi on BCR signalling and cell survival in CLL. In conclusion, this study advances our understanding of mechanisms of action of CD20 mAbs as single agents or in combination with BAKi and could inform on the potential of combined therapies in ongoing and future clinical trials in patients with CLL.

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.

CAL2 monoclonal antibody is a rapid and sensitive assay for the detection of calreticulin mutations in essential thrombocythemia patients.

Calreticulin (CALR) mutations are detected in the majority of JAK2 wild type patients with essential thrombocythemia (ET). Unlike JAK2V617F and MPL point mutations, CALR mutations are highly heterogeneous, with several types of indels being reported so far. CAL2 is a monoclonal antibody specifically recognizing the C-neoterminal peptide derived from all the frameshift mutations of CALR. We retrospectively analysed 172 ET patients diagnosed at our Institution from 1980 to 2015. In JAK2V617F- and MPLW515K/L-wild type patients CALR mutations were searched on peripheral blood and CAL2 immunostaining was performed on bone marrow. In addition, bone marrow biopsies were histologically reviewed for megakaryocytic features. Thirty-one patients (18%) were CALR-mutated. Concordance between molecular and immunohistological detection of CALR mutations was near complete, albeit a single patient was found to be positive by molecular tests only. Two patterns were defined in CAL2-positive bone marrow samples, characterized by staining of almost only megakaryocytes (pattern A: 41%) or staining of megakaryocytes and ≥ 2% small non megakaryocytic elements (pattern B: 59%), at least partially being myeloid precursors. Pattern B biopsies had higher cellularity and number of megakaryocytes compared to pattern A samples. In this series, CAL2 allowed rapid and cost-efficient identification of CALR-mutated ET patients. The biological significance of different staining pattern should be confirmed in wider and independent series.

Safety and efficacy of switching from branded to generic imatinib in chronic phase chronic myeloid leukemia patients treated in Italy.

The use of generic drugs after patent expiration of their originators is a relative novelty in the treatment of chronic cancer patients in Western countries. In this observational study we analyzed a cohort of 294 Italian chronic phase chronic myeloid leukemia patients treated frontline with branded imatinib (Glivec®) for at least 6 months and then uniformly switched to generic imatinib upon requirement of health authorities in early 2017. Median age at diagnosis was 57 years (range 19-87). Sokal risk was low/intermediate/high in 55%, 32% and 8% of cases, respectively. Median duration of branded imatinib treatment was 7.4 years (range 0.5-16.7). At a median follow-up of 7.5 months after switch to generic imatinib, 17% of patients reported new or worsening side effects, but grade 3-4 non-hematological adverse events were rare. Six patients switched back to branded imatinib, with improvement in the side effect profile, and 4 pts moved to bosutinib or nilotinib for resistance/intolerance. The majority of patients were in major (26%) or deep molecular response (66%) at the time of switch. Molecular responses remained stable, improved or worsened in 61%, 25% and 14% of patients, respectively. We conclude that switch to generic imatinib for patients who have been receiving branded imatinib appears to be effective and safe. Molecular responses may continue to improve over time. Some patients experienced new or worsened side effects but less than 5% of the whole cohort needed to switch back to branded imatinib or move to other treatments. Savings were around 3 million Euros.

Excellent outcomes of 2G-TKI therapy after imatinib failure in chronic phase CML patients.

Second-generation tyrosine kinase inhibitors (2G-TKIs) dasatinib and nilotinib produced historical rates of about 50% complete cytogenetic response (CCyR) and about 40% major molecular response (MMR) in chronic myeloid leukaemia (CML) patients failing imatinib. Direct comparisons between dasatinib and nilotinib are lacking, and few studies addressed the dynamics of deep molecular response (DMR) in a "real-life" setting. We retrospectively analyzed 163 patients receiving dasatinib (n = 95) or nilotinib (n = 68) as second-line therapy after imatinib. The two cohorts were comparable for disease's characteristics, although there was a higher rate of dasatinib use in imatinib-resistant and of nilotinib in intolerant patients. Overall, 75% patients not in CCyR and 60% patients not in MMR at 2G-TKI start attained this response. DMR was achieved by 61 patients (37.4%), with estimated rate of stable DMR at 5 years of 24%. After a median follow-up of 48 months, 60% of patients persisted on their second-line treatment. Rates and kinetics of cytogenetic and molecular responses, progression-free and overall survival were similar for dasatinib and nilotinib. In a "real-life" setting, dasatinib and nilotinib resulted equally effective and safe after imatinib failure, determining high rates of CCyR and MMR, and a significant chance of stable DMR, a prerequisite for treatment discontinuation.

Low catalase expression confers redox hypersensitivity and identifies an indolent clinical behavior in CLL.

B-cell receptor (BCR) signaling is a key determinant of variable clinical behavior and a target for therapeutic interventions in chronic lymphocytic leukemia (CLL). Endogenously produced H2O2 is thought to fine-tune the BCR signaling by reversibly inhibiting phosphatases. However, little is known about how CLL cells sense and respond to such redox cues and what effect they have on CLL. We characterized the response of BCR signaling proteins to exogenous H2O2 in cells from patients with CLL, using phosphospecific flow cytometry. Exogenous H2O2 in the absence of BCR engagement induced a signaling response of BCR proteins that was higher in CLL with favorable prognostic parameters and an indolent clinical course. We identified low catalase expression as a possible mechanism accounting for redox signaling hypersensitivity. Decreased catalase could cause an escalated accumulation of exogenous H2O2 in leukemic cells with a consequent greater inhibition of phosphatases and an increase of redox signaling sensitivity. Moreover, lower levels of catalase were significantly associated with a slower progression of the disease. In leukemic cells characterized by redox hypersensitivity, we also documented an elevated accumulation of ROS and an increased mitochondrial amount. Taken together, our data identified redox sensitivity and metabolic profiles that are linked to differential clinical behavior in CLL. This study advances our understanding of the redox and signaling heterogeneity of CLL and provides the rationale for the development of therapies targeting redox pathways in CLL.

Bortezomib, Thalidomide and Lenalidomide: Have They Really Changed the Outcome of Multiple Myeloma?

Treatment of multiple myeloma (MM) has significantly improved, although the disease remains incurable. Prospective clinical trials evaluating the impact on outcome of new drugs such as proteasome inhibitors or immunomodulating agents are limited since they are not able to reflect the clinical routine and available retrospective data are not detailed enough to directly evaluate the value of new drugs. To address these information gaps, we performed a retrospective real-life analysis. We retrospectively assessed 949 patients treated for multiple myeloma or plasma cell leukemia at three Italian cancer centers in the years 1979-2014. Clinical features at the time of diagnosis were consistent with what was observed in clinical routine. A total of 39% of patients underwent high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). The median overall survival (OS) of the whole group was 5.4 years and ranged from 3.4 years for patients who did not receive at least one of the new drugs compared to 5.9 years in the other patients (p<0.001). The improvement in OS due to administration of new drugs was also observed among different prognostic sub-groups such as age, Durie and Salmon stage, international staging system and renal impairment. Availability of new drugs significantly improved survival of patients who underwent ASCT and also those who did not. In conclusion, we provided evidence that the advent of the new drugs drastically improved the outcome of patients with MM, also in cases with poor risk at the time of diagnosis. ASCT is still of major importance in the treatment of this disease. Nevertheless, MM remains incurable and new therapeutic approaches are warranted.

Multicentre survey to explore current survival of patients with acute myeloid leukaemia who failed induction chemotherapy.

BACKGROUND: Acute myeloid leukaemia not responsive to first induction chemotherapy (PIF-AML) still remains a challenge, and there are only few recent epidemiological data regarding the outcome of these patients. In this multicentre survey, we evaluate the prognosis and outcome of patients with PIF-AML, who were diagnosed and treated in the last 5 yrs in four Italian institutions. RESULTS: One hundred PIF-AML were recorded, 57 males and 43 females, with a median age of 63 yrs (19-79), 42% were younger than 60 yrs; 42% had a secondary AML and 40% had an adverse karyotype. According to cytogenetic/molecular risk stratification at diagnosis, 33% of patients were classified as favourable/intermediate-1 risk and 56% as intermediate-2/adverse risk. After a median follow-up of 11 months (1-49), 77% of patients died, while 23% were alive (with 12/23 in cCR). Thirty-six patients underwent allogeneic SCT, and of these, 11 of 36 (31%) were alive at last follow-up. The 12- and 24-month OS probability of the whole population was 45% and 21%, respectively. In multivariate analysis, the probability of OS of the whole population was significantly improved by Allo-SCT procedure (12-month OS probability 60% vs. 35%; P < 0.0001) and was better in patients with favourable/intermediate-1 risk at diagnosis (12-month OS probability 58% vs. 40%; P = 0.028). In transplanted cases, a pretransplant responsive disease was the only significant factor to predict a favourable outcome after Allo-SCT (P = 0.006). CONCLUSION: Treatment options of PIF-AML still are limited and the prognosis, even recently, remains extremely poor. This survey shows that PIF-AML is still rarely cured without Allo-SCT and confirms the importance of initiating an urgent unrelated donor search in cases without a matched sibling donor. Moreover, the outcome of Allo-SCT is better in patients who achieve a good AML debulking before transplant. To reach this goal, new predictive scores and new protocols of salvage therapy (with target drugs or combinations) need to be explored urgently in PIF-AML.