Blinatumomab differentially modulates peripheral blood and bone marrow immune cell repertoire: A Campus ALL study

Blinatumomab is the first bi-specific T-cell engager approved for relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (B-ALL). Despite remarkable clinical results, the effects of blinatumomab on the host immune cell repertoire are not fully elucidated. In the present study, we characterized the peripheral blood (PB) and, for the first time, the bone marrow (BM) immune cell repertoire upon blinatumomab treatment. Twenty-nine patients with B-ALL received blinatumomab according to clinical practice. Deep multiparametric flow cytometry was used to characterize lymphoid subsets during the first treatment cycle. Blinatumomab induced a transient redistribution of PB effector T-cell subsets and Treg cells with a persistent increase in cytotoxic NK cells, which was associated with a transient upregulation of immune checkpoint receptors on PB CD4 and CD8 T-cell subpopulations and of CD39 expression on suppressive Treg cells. Of note, BM immune T-cell subsets showed a broader post-treatment subversion, including the modulation of markers associated with a T-cell-exhausted phenotype. In conclusion, our study indicates that blinatumomab differentially modulates the PB and BM immune cell repertoire, which may have relevant clinical implications in the therapeutic setting.

Posaconazole and midostaurin in patients with FLT3-mutated acute myeloid leukemia: Pharmacokinetic interactions and clinical facts in a real life study

Midostaurin is used in combination with chemotherapy to treat patients with newly diagnosed FLT3-mutated acute myeloid leukemia. Chemotherapy-induced neutropenia exposes these patients to a significant risk of invasive fungal infections (IFIs). International guidelines recommend primary antifungal prophylaxis with posaconazole (PCZ) but nested analysis of a phase III trial showed that strong PCZ inhibition of CYP3A4 diminished midostaurin metabolism and increased midostaurin plasma levels; however, midostaurin-related adverse events (AEs) were only moderately exacerbated. We conducted a prospective multicenter real-life study to evaluate (i) how often concerns around PCZ-midostaurin interactions made the hematologist prescribe antifungals other than PCZ, (ii) how remarkably PCZ increased midostaurin plasma levels, and (iii) how significantly PCZ-midostaurin interactions influenced hematologic and safety outcomes of induction therapy. Although the hematologists were blinded to pharmacokinetic findings, as many as 16 of 35 evaluable patients were prescribed antifungal prophylaxis with micafungin, weak CYP3A4 inhibitor, in place of PCZ (p < 0.001 for deviation from guidelines). In the 19 patients managed as per guidelines, PCZ-midostaurin interactions were more remarkable than previously characterized, such that at the end of induction therapy midostaurin minimum plasma concentration (Cmin ) was greater than three times higher than reported; moreover, midostaurin Cmin , maximum plasma concentration, and area under the curve were more than or equal to four times higher with PCZ than micafungin. Hematologic outcomes (complete remission and duration of severe neutropenia) and safety outcomes (midostaurin-related any grade or grade ≥3 AEs) were nonetheless similar for patients exposed to PCZ or micafungin, as was the number of breakthrough IFIs. In waiting for randomized phase III trials of new prophylaxis regimens, these findings show that PCZ should remain the antifungal of choice for the midostaurin-treated patient.

Oral anti-viral therapy for early COVID-19 infection in patients with haematological malignancies: A multicentre prospective cohort

High rates of lung failure have been reported in haematological patients after SARS-CoV2 infection. An early administration of monoclonal antibodies or anti-virals may improve the prognosis. Oral anti-virals may have a wider use independently of the genetic variations of the virus. Prospective data on anti-virals in haematological malignancies (HMs) are still lacking. Outpatients diagnosed with HM and early COVID-19 infection were prospectively treated with the oral anti-virals nirmatrelvir/ritonavir and molnupiravir. Incidence of lung failure, deaths and adverse events was analysed. Long-term outcome at third month was evaluated. Eighty-two outpatients were evaluable for the study objectives. All patients had been treated for their HM within 12 months. COVID-19-related lung failure was 23.1%. Active HM (aOR = 4.42; p = 0.038) and prolonged viral shedding (aOR = 1.04; p = 0.022) resulted independent predictors of severe infection. The vaccination with three to four doses (aOR = 0.02; p = 0.001) and with two doses (aOR = 0.06; p = 0.006) resulted protective. COVID-19-related deaths at 28 days were 6.1%. All-cause mortality at 90-day follow-up was 13.4% (n. 11) and included opportunistic infections and cardiovascular events. In conclusion, this approach reduced the incidence of lung failure and specific mortality compared to previous cohorts, but patients remain at high risk of further complications.

Multicenter Observational Retrospective Study on Febrile Events in Patients with Acute Myeloid Leukemia Treated with Cpx-351 in "Real-Life": The SEIFEM Experience

In the present study, we aimed to evaluate the absolute risk of infection in the real-life setting of AML patients treated with CPX-351. The study included all patients with AML from 30 Italian hematology centers of the SEIFEM group who received CPX-351 from July 2018 to June 2021. There were 200 patients included. Overall, 336 CPX-351 courses were counted: all 200 patients received the first induction cycle, 18 patients (5%) received a second CPX-351 induction, while 86 patients (26%) proceeded with the first CPX-351 consolidation cycle, and 32 patients (10%) received a second CPX-351 consolidation. A total of 249 febrile events were recorded: 193 during the first or second induction, and 56 after the first or second consolidation. After the diagnostic work-up, 92 events (37%) were classified as febrile neutropenia of unknown origin (FUO), 118 (47%) were classifiable as microbiologically documented infections, and 39 (17%) were classifiable as clinically documented infections. The overall 30-day mortality rate was 14% (28/200). The attributable mortality-infection rate was 6% (15/249). A lack of response to the CPX-351 treatment was the only factor significantly associated with mortality in the multivariate analysis [p-value: 0.004, OR 0.05, 95% CI 0.01-0.39]. Our study confirms the good safety profile of CPX-351 in a real-life setting, with an incidence of infectious complications comparable to that of the pivotal studies; despite prolonged neutropenia, the incidence of fungal infections was low, as was infection-related mortality.

Efficacy of Remdesivir and Neutralizing Monoclonal Antibodies in Monotherapy or Combination Therapy in Reducing the Risk of Disease Progression in Elderly or Immunocompromised Hosts Hospitalized for COVID-19: A Single Center Retrospective Study

INTRODUCTION

Remdesivir (REM) and monoclonal antibodies (mAbs) could alleviate severe COVID-19 in at-risk outpatients. However, data on their use in hospitalized patients, particularly in elderly or immunocompromised hosts, are lacking.

METHODS

All consecutive patients hospitalized with COVID-19 at our unit from 1 July 2021 to 15 March 2022 were retrospectively enrolled. The primary outcome was the progression to severe COVID-19 (P/F < 200). Descriptive statistics, a Cox univariate-multivariate model, and an inverse probability treatment-weighted (IPTW) analysis were performed.

RESULTS

Overall, 331 subjects were included; their median (q1-q3) age was 71 (51-80) years, and they were males in 52% of the cases. Of them, 78 (23%) developed severe COVID-19. All-cause in-hospital mortality was 14%; it was higher in those with disease progression (36% vs. 7%, p < 0.001). REM and mAbs resulted in a 7% (95%CI = 3-11%) and 14% (95%CI = 3-25%) reduction in the risk of severe COVID-19, respectively, after adjusting the analysis with the IPTW. In addition, by evaluating only immunocompromised hosts, the combination of REM and mAbs was associated with a significantly lower incidence of severe COVID-19 (aHR = 0.06, 95%CI = 0.02-0.77) when compared with monotherapy.

CONCLUSIONS

REM and mAbs may reduce the risk of COVID-19 progression in hospitalized patients. Importantly, in immunocompromised hosts, the combination of mAbs and REM may be beneficial.

Abstract 6163: Fusion landscape in acute leukemias: A submerged world of not routinely characterized transcripts

Background: Fusions (Fs) are major molecular biological abnormalities in acute leukemias (ALs), and all well-known Fs in leukemias are founder variations are routinely used as molecular markers for the diagnosis, classification, risk stratification, and targeted therapy but there is a considerable part of ALs that are not screened for other known/unknown transcripts. For example in B-Other B Acute Lymphoblastic Leukemia (B-ALL) [Ph-/-/-; negative for t(9;22); t(1;19); t(4;11); 61% of adult B-ALL], many chimeric genes have been identified leading to a refined classification of B-ALL and to, in some cases, tailored therapies. At this point, a RNA-seq approach is needed but challenging for many aspects, among them a not standardized and very heterogeneous F data analysis.

Aims: We developed and validated our integrated pipeline in order to assess targetable biomarkers and to better classify patients (pts).

Methods: we performed 1385 gene RNAseq (Illumina) of 224 adult AL samples (112 Ph-/-/-, 41 Ph+, 6 t(1;19), 16 T-LBL/T-ALL and 49 AML). Starting from Ph-/-/-, we developed a combined 4 tool analysis that is further implemented with a filtering strategy with a specific ALs fusion literature filter (Patent PCTEP2021-065692 and 749 ALL Fs database copyright) (Fig.1A). We validate our strategy using: RT-PCR, FISH SNP Arrays; MLPA and total RNA-seq.

Results: From 3022 candidate Fs, we retained 160 of them (5.3%; excluding WHO canonical Fs) not otherwise detected, in 120 pts with a high Fs rate in T-LBL/T-ALL, Ph-/-/- and Ph+ (62.5%, 62.2% and 61% respectively) denoting that ALs are not deeply characterized (Fig 1B). The lower rate was found in AML (26.5%), but we were able to identify new ETV6 rearrangement (r) and a FISH cryptic F in a 46, XY pt (TBL1XR1-MECOM). We validated 98 Fs that have been already reported in the literature and 43 novel F transcripts. We obtained a validation rate of 81%. The majority of fused samples (65.2%) had only one detectable F while a smaller group was characterized by multiple Fs. Many of these Fs were previously described in B/T-ALL and AML (e.g. KMT2A-MLLT1, ABL1/2-RCSD1, IGH-MYC, NUP214-SET, ETV6-MECOM). In our bigger sub-cohort (Ph-/-/-), 44 Fs out of 109 (40.3%) were never been reported in Ph- ALL cases. In 15 Ph-like pts, we identified and validate 11 new transcripts. Ph-/-/- F detection help to sub-classify our fused pts in Ph-/-/- subgroups (ZNF384r-11.8%; Ph-like-19.1%; DUX4r- 4.4%; HLFr, MLLr and BCL2/MYC in 2.9%; MEF2Dr-1.5%).

Conclusions: we identified pivotal transcripts in all ALs and an unexpected high rate of secondary Fs in adult ALs subgroups (52.4%) that are not characterized with conventional diagnostic methods. The use of an NGS approach and a powerful pipeline permit us to detect Fs useful for a better classification, prognostic identification (e.g. TBL1XR1-MECOM) and in some cases to find targetable Fs (e.g. ABL1-2/RCSD1, NUMA1-CSF1R, ZMYM2-FLT3). Supported by: L3P2505.

Citation Format: Anna Ferrari, Silvia Vitali, Eugenio Fonzi, Andrea Ghelli Luserna Di Rora, Chiara Domizio, Cristina Papayannidis, Maria Teresa Bochicchio, Giovanni Marconi, Daniele Dall'Olio, Michela Tebaldi, Michela Rondoni, Barbara Giannini, Fabio Giglio, Crescenza Pasciolla, Monica Fumagalli, Sara Galimberti, Gastone Castellani, Daniel Remondini, Giorgia Simonetti, Giovanni Martinelli. Fusion landscape in acute leukemias: A submerged world of not routinely characterized transcripts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6163.

Current therapies for chronic lymphocytic leukemia: risk and prophylaxis strategies for secondary/opportunistic infections

INTRODUCTION

Currently, the implementation of new therapeutic options for treatment of chronic lymphocytic leukemia (CLL) considerably improved the outcome of this disease. However, patients affected by CLL are at higher risk for infections, due to the state of immunosuppression related to hematologic disease and therapies. Consequently, anti-infective prophylaxis should be properly managed, according to risk factors for opportunistic infection, related to antineoplastic drugs and characteristics of patients.

AREAS COVERED

This review aims to summarize current knowledge on secondary/opportunistic infections during CLL treatment, including chemo-immunotherapies, Bruton Tyrosine Kinase inhibitors, idelalisib and venetoclax. In addition, possible schemes of prophylaxis are provided.

EXPERT OPINION

The establishment of a multidisciplinary team including hematologist and infectious diseases specialist is pivotal for the best management of anti-infective prophylaxis and prevention of new onset infections.

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.

High Incidence of Invasive Fungal Diseases in Patients with FLT3-Mutated AML Treated with Midostaurin: Results of a Multicenter Observational SEIFEM Study

The potential drug-drug interactions of midostaurin may impact the choice of antifungal (AF) prophylaxis in FLT3-positive acute myeloid leukemia (AML) patients. To evaluate the incidence of invasive fungal diseases (IFD) during the treatment of FLT3-mutated AML patients and to correlate it to the different AF prophylaxis strategies, we planned a multicenter observational study involving 15 SEIFEM centers. One hundred fourteen patients treated with chemotherapy + midostaurin as induction/reinduction, consolidation or both were enrolled. During induction, the incidence of probable/proven and possible IFD was 10.5% and 9.7%, respectively; no statistically significant difference was observed according to the different AF strategy adopted. The median duration of neutropenia was similar in patients with or without IFD. Proven/probable and possible IFD incidence was 2.4% and 1.8%, respectively, during consolidation. Age was the only risk factor for IFD (OR, 95% CI, 1.10 [1.03–1.19]) and complete remission achievement after first induction the only one for survival (OR, 95% CI, 5.12 [1.93–13.60]). The rate of midostaurin discontinuation was similar across different AF strategies. The IFD attributable mortality during induction was 8.3%. In conclusion, the 20.2% overall incidence of IFD occurring in FLT3-mutated AML during induction with chemotherapy + midostaurin, regardless of AF strategy type, was noteworthy, and merits further study, particularly in elderly patients.

CPX-351 treatment in secondary acute myeloblastic leukemia is effective and improves the feasibility of allogeneic stem cell transplantation: results of the Italian compassionate use program

Secondary acute myeloid leukemia (sAML) poorly responds to conventional treatments and allogeneic stem cell transplantation (HSCT). We evaluated toxicity and efficacy of CPX-351 in 71 elderly patients (median age 66 years) with sAML enrolled in the Italian Named (Compassionate) Use Program. Sixty days treatment-related mortality was 7% (5/71). The response rate at the end of treatment was: CR/CRi in 50/71 patients (70.4%), PR in 6/71 (8.5%), and NR in 10/71 (19.7%). After a median follow-up of 11 months relapse was observed in 10/50 patients (20%) and 12 months cumulative incidence of relapse (CIR) was 23.6%. Median duration of response was not reached. In competing risk analysis, CIR was reduced when HSCT was performed in first CR (12 months CIR of 5% and 37.4%, respectively, for patients receiving (=20) or not (=30) HSCT, p = 0.012). Twelve-months OS was 68.6% (median not reached). In landmark analysis, HSCT in CR1 was the only significant predictor of longer survival (12 months OS of 100 and 70.5%, for patients undergoing or not HSCT in CR1, respectively, p = 0.011). In conclusion, we extend to a real-life setting, the notion that CPX is an effective regimen for high risk AML patients and may improve the results of HSCT.

Monosomal karyotype in myeloid neoplasias: a literature review

In 2008, the concept of the monosomal karyotype (MK) in adult acute myeloid leukemia (AML) patients was introduced, defined by the presence of a chromosomal aberration pattern characterized by the presence of at least two autosomal monosomies or of one monosomy plus one or more structural aberrations (not including loss of a chromosome). We present a systematic review of the literature about the influence of the MK on the outcome of patients affected by myeloid malignancies (AML, myelodysplastic syndromes, and primary myelofibrosis). For this review, a comprehensive literature search using the term “monosomal karyotype” was performed, considering articles listed in MEDLINE. This analysis of the literature confirms the negative prognostic impact on survival of the MK in myeloid neoplasias. The detrimental effect of MK on AML patients’ outcome is independent of other variables, including adverse cytogenetic features, supporting the identification of this entity as a challenging subgroup of patients with distinct biologic and clinical features.