Effect of age and treatment on predictive value of measurable residual disease: implications for clinical management of adult patients with acute myeloid leukemia.

Measurable residual disease (MRD) is a powerful predictor of outcome in acute myeloid leukemia. In the early phases of treatment, MRD refines initial disease risk stratification and is used for the allocation to allogeneic transplant. Despite its well-established role, a relatively high fraction of patients eventually relapses albeit achieving MRDneg status. The aim of this work was to assess specifically the influence of baseline features and treatment intensity on the predictive value of an MRDneg status, particularly focusing on MRD2, measured after two consecutive chemotherapy cycles. Among baseline features, younger MRD2neg patients (<55 years) had a significantly longer disease-free survival (median not reached) compared to their older counterparts (median 25.0 months, P=0.013, hazard ratio=2.08). Treatment intensity, specifically the delivery of a high dose of cytarabine in induction or first consolidation, apparently had a pejorative effect on the outcome of MRD2neg patients compared to standard dose (P=0.048, hazard ratio=1.80), a finding also confirmed by the analysis of data extracted from the literature. The combination of age and treatment intensity allowed us to identify categories of patients, among those who reached a MRD2neg status, characterized by significantly different disease-free survival rate. Our data showed that variables such as age and intensity of treatment administered can influence the predictive value of MRD in patients with acute myeloid leukemia. In addition to underscoring the need for further improvement of MRD analysis, these findings call for a reasoned application of MRD data, as currently available, to modulate consolidation therapy on adequately estimated relapse rates.

Blinatumomab and Inotuzumab Ozogamicin Sequential Use for the Treatment of Relapsed/Refractory Acute Lymphoblastic Leukemia: A Real-Life Campus All Study.

BACKGROUND: Blinatumomab (Blina) and inotuzumab ozogamicin (InO) has improved the outcome of relapsed/refractory B-lymphoblastic leukemia (R/R B-ALL). However, little is known about the outcome after recurrence and re-treatment with immunotherapy. METHODS: We describe 71 R/R B-ALL patients treated for different relapses with Blina and InO. Blina was the first treatment in 57 patients and InO in 14. Twenty-seven patients had a previous allogeneic hematopoietic stem cell transplantation (allo-HSCT). RESULTS: In the Blina/InO group, after Blina, 36 patients (63%) achieved a complete remission (CR), with 42% of negative minimal residual disease (MRD-); after InO, a CR was achieved in 47 patients (82%, 34 MRD-). In the InO/Blina group, after InO, 13 cases (93%) reached a CR (6 MRD-); after Blina, a CR was re-achieved in 6 cases (43%, 3 MRD-). Twenty-six patients proceeded to allo-HSCT. In the Blina/InO group, the median overall survival (OS) was 19 months; the disease-free survival (DFS) after Blina was 7.4 months (11.6 vs. 2.7 months in MRD- vs. MRD+, p = 0.03) and after InO, 5.4 months. In the InO/Blina group, the median OS was 9.4 months; the median DFS after InO was 5.1 months and 1.5 months after Blina (8.7 vs. 2.5 months in MRD- vs. MRD+, p = 0.02). With a median follow-up of 16.5 months from the start of immunotherapy, 24 patients (34%) are alive and 16 (22%) are alive in CR. CONCLUSION: In our series of R/R B-ALL, Blina and InO treatment demonstrate efficacy for subsequent relapses in terms of MRD response, OS and DFS, and as a bridge to allo-HSCT.

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.

Orphan Drug Use in Patients With Rare Diseases: A Population-Based Cohort Study.

Background: Orphan drugs are used for the diagnosis, prevention and treatment of rare diseases that, in the European Union, are defined as disorders affecting no more than 5 persons in 10,000. So far, a total of around 800 orphan medicinal products have been approved by the European Medicines Agency, however the utilization profile of orphan drugs has yet to be explored. This study aimed at assessing the utilization profile of orphan drugs authorized for marketing by the Italian Medicines Agency using population-based data. Methods: A total of 21 orphan drugs used in outpatient settings, approved in the European Union before or during the 2008-2018 period and involving 15 rare diseases, were included in the study. The monitored population included patients with one of the conditions surveilled by the population-based Tuscany Registry of Rare Diseases and diagnosed between 2000-2018. A multi-database approach was applied, by linking data from the registry with information collected in drug prescriptions databases. The prevalence and intensity of use were estimated for the selected orphan drugs and other non-orphan medications, used to treat the same rare disease and for which a change in the prevalence of use was hypothesized after authorization of the orphan drug. Results: For some diseases (acquired aplastic anemia, tuberous sclerosis complex, most metabolic diseases) a low prevalence of orphan drugs use was observed (range between 1.1-12.5%). Conversely, orphan drugs were frequently used in hemophilia B, Wilson disease and idiopathic pulmonary fibrosis (maximum of 78.3, 47.6 and 41.8%, respectively). For hemophilia B and Leber's hereditary optic neuropathy, there are currently no other medications used in clinical practice in addition to orphan drugs. Six orphan drugs were used for the treatment of pulmonary arterial hypertension, appearing the elective therapy for this disease, albeit with different utilization profiles (range of prevalence 1.7-55.6%). Conclusion: To the best of our knowledge, this is the first study investigating the utilization profile of orphan drugs prescribed in a defined geographical area, and providing relevant information to monitor over time potential changes in the prevalence of these medications as well as in the health care decision making.

Making Treatment-Free Remission (TFR) Easier in Chronic Myeloid Leukemia: Fact-Checking and Practical Management Tools.

In chronic-phase chronic myeloid leukemia (CML), tyrosine kinase inhibitors (TKIs) are the standard of care, and treatment-free remission (TFR) following the achievement of a stable deep molecular response (DMR) has become, alongside survival, a primary goal for virtually all patients. The GIMEMA CML working party recently suggested that the possibility of achieving TFR cannot be denied to any patient, and proposed specific treatment policies according to the patient's age and risk. However, other international recommendations (including 2020 ELN recommendations) are more focused on survival and provide less detailed suggestions on how to choose first and subsequent lines of treatment. Consequently, some grey areas remain. After literature review, a panel of Italian experts discussed the following controversial issues: (1) early prediction of DMR and TFR: female sex, non-high disease risk score, e14a2 transcript and early MR achievement have been associated with stable DMR, but the lack of these criteria is not sufficient to exclude any patient from TFR; (2) criteria for first and subsequent line therapy choice: a number of patient and drug characteristics have been proposed to make a personalized decision; (3) monitoring of residual disease after discontinuation: after the first 6 months, the frequency of molecular tests can be reduced based on MR4.5 persistence and short turnaround time; (4) prognosis of TFR: therapy and DMR duration are important to predict TFR; although immunological control of CML plays a role, no immunological predictive phenotype is currently available. This guidance is intended as a practical tool to support physicians in decision making.

Venetoclax-Based Regimens for Relapsed/Refractory Acute Myeloid Leukemia in a Real-Life Setting: A Retrospective Single-Center Experience.

Relapsed/refractory (R/R) acute myeloid leukemia (AML) is a largely unmet medical need, owing to the lack of standardized, effective treatment approaches, resulting in an overall dismal outcome. The only curative option for R/R AML patients is allogeneic hematopoietic stem cell transplantation (HSCT) which is only applicable in a fraction of patients due to the scarce efficacy and high toxicity of salvage regimens. Recently, a number of targeted agents with relatively favorable toxicity profiles have been explored in clinical trials for R/R AML patients. The Bcl-2 inhibitor venetoclax, in combination with hypomethylating agents or low dose cytarabine, has produced impressive results for newly diagnosed AML, while its role in R/R disease is not well defined yet. We retrospectively analyzed the clinical outcomes of 47 R/R AML patients treated with venetoclax-based regimens between March 2018 and December 2020 at our institution. Overall, we report a composite complete response rate of 55% with an overall acceptable toxicity profile. Outcomes were particularly favorable for NPM1 mutated patients, unlike for FLT3-ITD positive patients irrespective of NPM1 status. For patients treated with intention to transplant, the procedure could be finally performed in 54%. These findings suggest a role for venetoclax-based regimens in R/R AML patients and support the design of prospective studies.

Successful use of caplacizumab in a case of refractory acquired thrombotic thrombocytopenic purpura following subacute thyroiditis.

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare condition mainly characterized by microangiopathic hemolytic anemia, thrombocytopenia, reported in approximately three cases per one million adults per year. Some reports describing co-occurrence of aTTP and other autoimmune disorders, as Graves' thyroiditis, are reported. To the best of our knowledge this is the first report describing co-occurrence of subacute thyroiditis and aTTP. The patient was refractory to conventional therapy with plasma exchange, steroids and rituximab but was successfully treated with the addition of caplacizumab, an anti-VWF bivalent variable-domain-only immunoglobulin fragment that inhibits interaction between VWF multimers and platelets.

Multilineage Dysplasia as Assessed by Immunophenotype in Acute Myeloid Leukemia: A Prognostic Tool in a Genetically Undefined Category.

Acute myeloid leukemia (AML) "with myelodysplasia-related changes (MRC)" is considered a separate entity by the World Health Organization (WHO) classification of myeloid neoplasms. While anamnestic and cytogenetic criteria provide objective attribution to this subset, with clear unfavorable prognostic significance, the actual role of multi-lineage dysplasia (MLD) as assessed by morphology is debated. The aim of our work was to study MLD by a technique alternative to morphology, which is multiparameter flow cytometry (MFC), in a large series of 302 AML patients intensively treated at our Center. The correlation with morphology we observed in the unselected analysis reiterated the capability of the MFC-based approach at highlighting dysplasia. MLD data, estimated through an immune-phenotypic score (IPS), provided no insight into prognosis when considered overall nor within well-defined genetic categories. Of interest, IPS-related dysplasia conveyed significant prognostic information when we focused on genetically undefined patients, triple-negative for NPM1, FLT3 and CEBPA (TN-AML). In this context, the lack of dysplastic features (IPS_0) correlated with a significantly higher CR rate and longer survival compared to patients showing dysplasia in one or both (neutrophil and erythroid) cell lineages. The impact of IPS category maintained its validity after censoring at allogeneic HSCT and in a multivariate analysis including baseline and treatment-related covariates. In a subgroup featured by the lack of genetic determinants, our data could help address the relative unmet needs in terms of risk assessment and treatment strategy, and provide insight into prediction of response in the rapidly evolving therapeutic scenario of AML.

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.

In Vitro Comparison of the Effects of Imatinib and Ponatinib on Chronic Myeloid Leukemia Progenitor/Stem Cell Features.

BACKGROUND: The development of molecularly tailored therapeutic agents such as the BCR/ABL-active tyrosine kinase inhibitors (TKi) resulted in an excellent treatment option for chronic myeloid leukemia (CML) patients. However, following TKi discontinuation, disease relapses in 40-60% of patients, an occurrence very likely due to the persistence of leukemic stem cells that are scarcely sensitive to TKi. Nevertheless, TKi are still the only current treatment option for CML patients. OBJECTIVE: The aim of this study was to compare the effects of TKi belonging to different generations, imatinib and ponatinib (first and third generation, respectively), on progenitor/stem cell expansion potential and markers. PATIENTS AND METHODS: We used stabilized CML cell lines (KCL22, K562 and LAMA-84 cells), taking advantage of the previous demonstration of ours that cell lines contain cell subsets endowed with progenitor/stem cell properties. Primary cells explanted from CML patients were also used. The effects of TKi on the expression of stem cell related genes were compared by quantitative PCR. Flow cytometry was performed to evaluate aldehyde-dehydrogenase (ALDH) activity and the expression of cluster of differentiation (CD) cell surface hematopoietic stem cell markers. Progenitor/stem cell potential was estimated by serial colony formation ability (CFA) assay. RESULTS: Ponatinib was more effective than imatinib for the reduction of cells with ALDH activity and progenitor/stem cell potential of CML patient-derived cells and cell lines. Furthermore, ponatinib was more effective than imatinib in reducing the percentage of CD26-expressing cells in primary CML cells, whereas imatinib and ponatinib showed similar efficacy on KCL22 cells. Both drugs strongly upregulated NANOG and SOX2 in CML cell lines, but in KCL22 cells this upregulation was significantly lower with ponatinib than with imatinib, an outcome compatible with a lower level of enrichment of the stem cell compartment upon ponatinib treatment. CONCLUSION: Ponatinib seems to target CML progenitor/stem cells better than imatinib.

Early peripheral blast cell clearance predicts minimal residual disease status and refines disease prognosis in acute myeloid leukemia.

Minimal residual disease (MRD) assessment in acute myeloid leukemia (AML) is increasingly used in risk stratification. However, several issues around this use are unresolved, including, among others, the most suitable time-point(s) for its application. Overall, late assessments appear more effective at distinguishing outcome but, in some studies, the early evaluations were already highly informative, anticipating the value of later ones. Our work integrated MRD with peripheral blast clearance (PBC), a treatment-related biomarker previously demonstrated to be a powerful predictor of response. From 2007 to 2014, we have studied 120 patients treated according to the NILG 02-06 trial and who achieved CR after induction. Patients in PBC-defined categories (separated by a 1.5-log threshold) showed significantly different probabilities of attaining MRD negativity, after either induction (MRD1) or consolidation (MRD2). Peripheral blast clearance combined with MRD1 largely anticipated MRD2-related information: when both biomarkers predicted chemosensitive disease (PBChigh /MRD1neg ), the rate of MRD2-negativity was 90%, and DFS and OS estimates were 68% and 76% at 3 years, respectively. When both markers were unfavorable (PBClow /MRD1pos ), rates of MRD2 negativity, DFS, and OS were 20%, 34%, and 24%, respectively, at 3 years. In fact, MRD2 added prognostic value only in cases with discordant PBC/MRD1 data. Our data support a reasoned timing for MRD-based therapeutic decisions, modulated on individual chemosensitivity, an approach we have implemented in a forthcoming prospective multi-center trial by Gruppo Italiano Malattie EMatologiche dell'Adulto (GIMEMA).

Real-world experience with decitabine as a first-line treatment in 306 elderly acute myeloid leukaemia patients unfit for intensive chemotherapy.

Despite widespread use of decitabine to treat acute myeloid leukaemia (AML), data on its effectiveness and safety in the real-world setting are scanty. Thus, to analyze the performance of decitabine in clinical practice, we pooled together patient-level data of three multicentric observational studies conducted since 2013 throughout Italy, including 306 elderly AML patients (median age 75 years), unfit for intensive chemotherapy, treated with first-line decitabine therapy at the registered schedule of 20 mg/m2 /iv daily for 5 days every 4 weeks. Overall response rate (ORR), overall survival (OS) curves, and multivariate hazard ratios (HRs) of all-cause mortality were computed. Overall, 1940 cycles of therapy were administered (median, 5 cycles/patient). A total of 148 subjects were responders and, therefore, ORR was 48.4%. Seventy-one patients (23.2%) had complete remission, 32 (10.5%) had partial remission, and 45 (14.7%) had haematologic improvement. Median OS was 11.6 months for patients with favourable-intermediate cytogenetic risk and 7.9 months for those with adverse cytogenetic risk. Median relapse-free survival after CR was 10.9 months (95% confidence interval [CI]: 8.7-16.0). In multivariate analysis, mortality was higher in patients with adverse cytogenetic risk (HR=1.58; 95% CI: 1.13-2.21) and increased continuously with white blood cell (WBC) count (HR=1.12; 95% CI: 1.06-1.18). A total of 183 infectious adverse events occurred in 136 patients mainly (>90%) within the first five cycles of therapy. This pooled analysis of clinical care studies confirmed, outside of clinical trials, the effectiveness of decitabine as first-line therapy for AML in elderly patients unfit for intensive chemotherapy. An adverse cytogenetic profile and a higher WBC count at diagnosis were, in this real life setting, unfavourable predictors of survival.

Lenograstim and filgrastim in the febrile neutropenia prophylaxis of hospitalized patients: efficacy and cost of the prophylaxis in a retrospective survey.

PURPOSE: We conducted a retrospective study to evaluate the efficacy and related costs of using two different molecules of granulocyte-colony stimulating factor (G-CSF) (lenograstim - LENO or filgrastim - FIL) as primary prophylaxis of chemotherapy-induced neutropenia in a hematological inpatient setting. METHODS: The primary endpoints of the analysis were the efficacy of the two G-CSFs in terms of the level of white blood cells, hemoglobin and platelets at the end of the treatment and the per capita direct medical costs related to G-CSF prophylaxis. RESULTS: Two hundred twelve patients (96 LENO, 116 FIL) have been evaluated. The following statistically significant differences have been observed between FIL and LENO: the use of a higher number of vials (11 vs 7; P<0.03) to fully recover bone marrow, a higher grade 3-4 neutropenia at the time of G-CSF discontinuation (29.3% vs 16.7%; P=0.031) and an increased number of days of hospitalization (8 vs 5; P<0.005). A longer hospital stay before discharge was necessary (12 vs 10), which reflects the higher final costs per patient (median treatment cost per cycle 10.706 € for LENO, compared to 12.623 € for FIL). CONCLUSION: The use of LENO has been associated with a lower number of days of hospitalization, number of vials and less incidence of grade 3-4 neutropenia at the time of G-CSF discontinuation. LENO seems to be cost-saving when compared with FIL (-15.2%).

The hOCT1 and ABCB1 polymorphisms do not influence the pharmacodynamics of nilotinib in chronic myeloid leukemia.

First-line nilotinib in chronic myeloid leukemia is more effective than imatinib to achieve early and deep molecular responses, despite poor tolerability or failure observed in one-third of patients. The toxicity and efficacy of tyrosine kinase inhibitors might depend on the activity of transmembrane transporters. However, the impact of transporters genes polymorphisms in nilotinib setting is still debated. We investigated the possible correlation between single nucleotide polymorphisms of hOCT1 (rs683369 [c.480C>G]) and ABCB1 (rs1128503 [c.1236C>T], rs2032582 [c.2677G>T/A], rs1045642 [c.3435C>T]) and nilotinib efficacy and toxicity in a cohort of 78 patients affected by chronic myeloid leukemia in the context of current clinical practice. The early molecular response was achieved by 81% of patients while 64% of them attained deep molecular response (median time, 26 months). The 36-month event-free survival was 86%, whereas 58% of patients experienced toxicities. Interestingly, hOCT1 and ABCB1 polymorphisms alone or in combination did not influence event-free survival or the adverse events rate. Therefore, in contrast to data obtained in patients treated with imatinib, hOCT1 and ABCB1 polymorphisms do not impact on nilotinib efficacy or toxicity. This could be relevant in the choice of the first-line therapy: patients with polymorphisms that negatively condition imatinib efficacy might thus receive nilotinib as first-line therapy.

CEBPA-double-mutated acute myeloid leukemia displays a unique phenotypic profile: a reliable screening method and insight into biological features.

Mutations in CCAAT/enhancer binding protein α (CEBPA) occur in 5-10% of cases of acute myeloid leukemia. CEBPA-double-mutated cases usually bear biallelic N- and C-terminal mutations and are associated with a favorable clinical outcome. Identification of CEBPA mutants is challenging because of the variety of mutations, intrinsic characteristics of the gene and technical issues. Several screening methods (fragment-length analysis, gene expression array) have been proposed especially for large-scale clinical use; although efficient, they are limited by specific concerns. We investigated the phenotypic profile of blast and maturing bone marrow cell compartments at diagnosis in 251 cases of acute myeloid leukemia. In this cohort, 16 (6.4%) patients had two CEBPA mutations, whereas ten (4.0%) had a single mutation. First, we highlighted that the CEBPA-double-mutated subset displays recurrent phenotypic abnormalities in all cell compartments. By mutational analysis after cell sorting, we demonstrated that this common phenotypic signature depends on CEBPA-double-mutated multi-lineage involvement. From a multidimensional study of phenotypic data, we developed a classifier including ten core and widely available parameters. The selected markers on blasts (CD34, CD117, CD7, CD15, CD65), neutrophil (SSC, CD64), monocytic (CD14, CD64) and erythroid (CD117) compartments were able to cluster CEBPA-double-mutated cases. In a validation set of 259 AML cases from three independent centers, our classifier showed excellent performance with 100% specificity and 100% sensitivity. We have, therefore, established a reliable screening method, based upon multidimensional analysis of widely available phenotypic parameters. This method provides early results and is suitable for large-scale detection of CEBPA-double-mutated status, allowing gene sequencing to be focused in selected cases.

Genetic predisposition and induced pro-inflammatory/pro-oxidative status may play a role in increased atherothrombotic events in nilotinib treated chronic myeloid leukemia patients.

Several reports described an increased risk of cardiovascular (CV) events, mainly atherothrombotic, in Chronic Myeloid Leukemia (CML) patients receiving nilotinib. However, the underlying mechanism remains elusive. The objective of the current cross-sectional retrospective study is to address a potential correlation between Tyrosine Kinase Inhibitors (TKIs) treatment and CV events. One hundred and 10 chronic phase CML patients in complete cytogenetic response during nilotinib or imatinib, were screened for CV events and evaluated for: traditional CV risk factors, pro/anti-inflammatory biochemical parameters and detrimental ORL1 gene polymorphisms (encoding for altered oxidized LDL receptor-1). Multivariate analysis of the whole cohort showed that the cluster of co-existing nilotinib treatment, dyslipidaemia and G allele of LOX-1 polymorphism was the only significant finding associated with CV events. Furthermore, multivariate analysis according to TKI treatment confirmed IVS4-14 G/G LOX-1 polymorphism as the strongest predictive factor for a higher incidence of CV events in nilotinib patients. Biochemical assessment showed an unbalanced pro-inflammatory cytokines network in nilotinib vs imatinib patients. Surprisingly, pre-existing traditional CV risk factors were not always predictive of CV events. We believe that in nilotinib patients an induced "inflammatory/oxidative status", together with a genetic pro-atherothrombotic predisposition, may favour the increased incidence of CV events. Prospective studies focused on this issue are ongoing.