Detection of measurable residual disease in adults with acute leukaemia

Introduction. Measurable residual disease (MRD) is a residual amount of malignant cells able to invoke relapse after complete haematological remission.Aim. Analysis of the MRD prognostic value in various treatment protocols for acute leukaemia.Main findings. MRD is a good prognostic indicator in lymphoblastic and myeloid leukaemia. Quantification of residual tumour cells is used for patient risk stratification according to the relapse prognosis. Stratification data, including MRD estimates at check points, may impact therapy choice, such as transplantation of allogeneic haematopoietic stem cells. Therefore, MRD estimation in acute leukaemia has become mandatory in clinical trial and research.

Hepatitis-associated Aplastic Anaemia in Children

Background Children with idiopathic acute liver failure (IALF) are at a high risk of developing life-threatening bone marrow failure (BMF). The aim of the study was to describe the development, therapy and prognosis of this hepatitis-associated aplastic anaemia (HAAA) in comparison to isolated acquired aplastic anaemia. Results We retrospectively found 18 patients (9 female) of HAAA between 1984 and 2017 with an age of 1.4–16.4 years. Fifteen of them fulfilled the SAA criteria, 3 had a bone marrow hypoplasia. Eleven of these children received liver transplantation (LTx) (these were 11 of 42 (26%) children receiving LTx for IALF), 6 patients recovered without LTx. The first signs of BMF, thrombocytopaenia and leucocytopaenia, occurred before LTx in all cases. During the follow-up period 8 patients reached haematological remission, 6 received haematopoietic stem cell transplantation (HSCT). Seven children died in a median of 304 days after the first symptoms mostly because of bleedings and infections. To date, extensive investigations failed to detect a genetically, viral or immunological aetiology. No AA was diagnosed in the 41 patients receiving liver transplants during the same period for ALF of known aetiology. As a comparison group, we collected the data of patients with isolated SAA. 73% achieved a remission after Immunosuppressive therapy (IST) without HSCT, and none of them died during the follow-up period. Conclusion Blood counts should be examined early and regularly (0–22 days after onset) in patients with IALF. Aggressive treatment with LTx, IST and HSCT appears to improve the prognosis.

Complement-Inhibiting Therapy of Atypical Haemolytic Uremic Syndrome in a Patient With Factor H Mutation

Atypical haemolytic uremic syndrome (aHUS) is an extremely rare pathology with the development of complement-mediated thrombotic microangiopathy (TMA). Before eculizumab, a humanized IgG monoclonal antibody to the complement component C5, the prognosis of total and renal survival with aHUS was unfavourable due to the high probability of death and the development of end-stage chronic renal failure in surviving patients. This article presents a clinical observation of a patient with aHUS who had an identified heterozygous factor H (CFH) mutation — c.3653G>A(p.Cys1218Tyr), and two heterozygous variants of polymorphism in the same gene — c.2016A>G; c.2808G>T. Despite the achievement of haematological remission of TMA against the background of plasma therapy, the child developed dialysis-dependent renal failure. Treatment with eculizumab in a patient with chronic kidney damage provided a significant improvement in their function, maintaining a stable remission and improving the quality of life of the patient with aHUS.Kh. М. Emirova, Е. S. Stolyarevich take part in educational events for doctors as lecturers with the support of Alexion Pharma. The other contributors confirmed the absence of a reportable conflict of interest.

Efficacy of Carfilzomib, Lenalidomide, and Dexamethasone for Extramedullary Intracranial Localization of Multiple Myeloma

EMD of myeloma usually occurs several years after diagnosis and is associated with a very poor OS of <6 months due to the fact that there are no efficient treatment options. In rrMM with EMDs, the most effective treatment is a lymphoma-like polychemotherapy regimen such as PACE, Dexa-BEAM, and HyperCVAD followed by ASCT or allogeneic SCT. RT of soft-tissue plasmacytoma is the further treatment choice and results in a high rate of local control and a prolonged disease-free survival. We report the case of a 41-year-old man affected by ultra-high-risk symptomatic IgAλMM with extramedullary intracranial soft-tissue relapsed after VTD-PACE followed by ASCT. The salvage program with KRd regimen determines a second biochemical and haematological remission and a gradual reduction in size of the extramedullary intracranial soft-tissue even in the absence of local aggressive radiotherapy, suggesting that carfilzomib and lenalidomide together could be effective also in this critical situation.

Idelalisib Rapidly Improves Platelets Function in Patients with Chronic Lymphocytic Leukemia (CLL)

INTRODUCTION Platelet function has never been studied systematically in patients with CLL. Novel drugs are now available for CLL treatment that may impact on platelet functions. Fifty per cent of patients treated with Ibrutinib suffered from minor bleedings and only 5% from major bleedings, partly caused by the drug driven inhibition of platelet glycoprotein VI signaling. No data on bleeding tendency has yet emerged on patient treated with Idelalisib, the first specific inhibitor of PI3K δ p110 approved for the treatment of relapsed/refractory CLL or for patients with del17p or TP53 as first line therapy. In animal models a reduction of p110δ on platelets (PLT) does not increase bleeding, causing only a slight reduction of platelet aggregation and activation. Knowledge about potential bleeding complications associated with the use of small molecules may be relevant in older patients and those at increased bleeding risk due to concomitant therapies. PATIENTS AND METHODS Ten patients with CLL (M/F: 6/4; median age: 71 years, range 47-82) who started therapy with Idelalisib were enrolled in a prospective observational pilot study. The Bleeding Severity Score (BSS), a validated questionnaire, was administrated to patients to estimate bleeding before and during idelalisib therapy. All patients underwent coagulation tests and platelet aggregation/secretion studies with different aggregating agents before starting therapy with Idelalisib, after 28 + 7 days and after 3 months. Patients with a platelet count less than 80.000/mm3, in antiplatelet or anticoagulant therapy, with recent use (within 7 days) of NSAIDs and a diagnosis of hereditary thrombocytopenia/pathy were excluded. We defined complete haematological remission (CHR) as Hb more than 11g/dl, PLT more than 100.000/mm3, lymphocyte less than 5.000/mm3 and partial haematological remission (PHR) as a response not fulfilling criteria for CHR. RESULTS No cases of hemorrhagic complications or increased bleeding tendency were observed in patients with CLL and no patients had a pathologic BSS (>5) at enrolment. All patients had coagulation tests within normal limits at baseline and after 28 days. Platelet count was below 100.000/mm3 in 5 patients. In 9 out of 10 patients platelet aggregation was pathological with at least 2 of the 4 aggregating agents tested. Platelet secretion before initiation of treatment with Idelalisib was particularly impaired with ADP (8/10 patients), while was pathological with collagen, a strong agonist, in only 2 patients. In 8 patients intraplatelet ATP/ADP ratio was pathological, as observed in delta storage pool disease. After 28 days of treatment 4 of 10 patients were in CHR and 3 in PHR. Platelets count was still below 100.000/mm3 in 2 subjects. At 28 days in 5 out of the 9 patients with pathological baseline test, platelet aggregation improved, while 3 remained unchanged and in one worsened. Even ADP secretion normalized in 4 patients. ATP/ADP ratio did not significantly change. At three months 7 patients reached CR and 2 reached PR. At three months platelets count was still below 100000/mm3 in 2 patients. In 3 patients platelet aggregation further ameliorated. CONCLUSIONS In this pilot study, treatment with idelalisib improved platelet aggregation tests in most of the CLL patients who presented a pathological test before starting therapy. It's unlikely that the drug has a direct effect on platelets, given their low expression of PI3Kδ; therefore our results are probably due to the rapid idealisib effect on CLL clone. Based on these preliminary data, Idelalisib seems to be safe in patients with an increased bleeding risk. Disclosures Reda: Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Research Funding. Peyvandi:Alexion: Other: research funding paid to Luigi Villa Foundation, Research Funding; Ablynx: Membership on an entity's Board of Directors or advisory committees, Other: research funding paid to Luigi Villa Foundation, Research Funding; CSL Behring: Speakers Bureau; Biotest: Other: research funding paid to Luigi Villa Foundation, Research Funding, Speakers Bureau; Octapharma: Consultancy; Kedrion Biopharma: Consultancy, Other: research funding paid to Luigi Villa Foundation, Research Funding; LFB: Consultancy; Grifols: Speakers Bureau; Novo Nordisk: Other: research funding paid to Luigi Villa Foundation, Research Funding, Speakers Bureau; SOBI: Speakers Bureau; Bayer: Speakers Bureau.

Is Having Clonal Cytogenetic Abnormalities the Same as Having Leukaemia?

A finding of cytogenetic abnormalities, even when these are clonal and even when the abnormalities are typically associated with leukaemia, is not the same as a person having leukaemia. We describe a person who had acute myeloid leukaemia (AML) and achieved a complete haematological remission and who then had persistent and transient clonal cytogenetic abnormalities for 22 years but no recurrence of leukaemia. These data suggest that clones of myeloid cells with mutations and capable of expanding to levels detectable by routine cytogenetic analyses do not all eventuate in leukaemia, even after a prolonged observation interval. The possibility of incorrectly diagnosing a person as having leukaemia becomes even greater when employing more sensitive techniques to detect mutations such as by polymerase chain reaction and whole-exome or whole-genome sequencing. Caution is needed when interpreting clonal abnormalities in AML patients with normal blood and bone marrow parameters.

Azacitidine Treatment in High Risk Myelodysplastic Patients in Complete Haematological Remission Reverts Mesenchymal Stem Cells to a Normal Phenotype

Introduction. Myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal hematopoietic stem cell (HSC) malignancies that are characterized by ineffective bone marrow hematopoiesis, peripheral blood cytopenias, and a substantial risk for progression to acute myeloid leukemia. Mesenchymal stem cells (MSCs) isolated from bone marrow of patients affected by myelodysplastic syndromes (MDS) play a critical role in myelodysplastic microenvironment showing altered structural epigenetic and functional features. Methods. In this work we evaluated the effect of azacitidine treatment on MSC-MDS. In particular, we analyzed MSC-MDS from 24 high-risk patients at diagnosis and after azacitidine treatment, studying their morphology, proliferative potential, cell cycle activity and their capacity to support haematopoiesis. Results. MDS-MSCs at diagnosis appeared larger and flattened, achieved confluence at a significantly lower rate than donors and displayed reduced proliferative capacity. In particular 40% of samples were unable to expand. This reduced proliferative capacity of MSC-MDS at diagnosis suggested changes in the cell cycle activity. Therefore we studied the gene expression profiles of 37 regulatory genes, observing CDKN2B up-regulation in MDS-MSCs (8 times higher than donors). Notably, after azacitidine treatment MDS-MSCs of patients who reached complete haematological remission (MDS-MSCs-CR) reverted to the typical BM-MSC morphology and recovered a proliferative potential similar to normal BM-MSC achieving confluence at a significantly higher rate. Molecular analysis on MDS-MSC-CR revealed a significant reduction in the expression level of CDKN2B showing correlation between cell cycle progression and expression level of this gene. Moreover, to study the long-term hematopoietic maintaining ability, MDS-MSCs at diagnosis were cultured with CD133+ cells, and they showed a decreased ability to support the growth of myeloid and erythroid progenitors. Conversely, MSC-MDS-CR showed an increased capacity to support haematopoiesis similar to healthy donors. Conclusion. We showed that MDS-MSCs at diagnosis were structurally and functionally altered while MSC-MDS-CR after azacitidine revert to a normal phenotype. It has been supposed that healthy MSCs adopt MDS-MSCs like molecular features when exposed to haematopoietic MDS cells. Our results may confirm these data suggesting that myelodysplastic cells can alter bone marrow microenvironment interacting with MSC and affecting their normal role and functionality. Disclosures No relevant conflicts of interest to declare.

Long-Term Remission Maintenance on Weekly Imatinib Dosage In Patients with FIP1L1-PDGFRA-Positive Chronic Eosinophilic Leukaemia

Abstract 4097 A small subset of patients with hypereosinophilic syndrome (HES) presents an interstitial deletion in chromosome 4q12, which leads to the expression of an imatinib -responsive fusion gene- called FIP1L1-PDGFRA (F/P). These patients have chronic eosinophilic leukemia (CEL). Here, we treated twenty five F/P-positive CEL patients (22 male, 2 female; median age of 50 years) with imatinib using initial daily doses ranging from 100 – 400 mg. At diagnosis a median peripheral blood eosinophilia and eosinophil marrow infiltration were 12×109/L (range 2.5–40.8) and 39% (range 7–80), respectively. Splenomagaly was the most frequent clinical manifestation in this patient subgroup. All imatinib-treated patients achieved clinical and molecular response. A complete haematological remission (CHR) was demonstrated after median of 13 days (range 3–90) whereas molecular response (MR) was confirmed after median of 9 months (range 3–24). In a remission maintenance phase, imatinib doses were de-escalated and they were following: 100mg once weekly (n=11), 100mg twice weekly (n=6), 100mg daily (n=5), 200mg once weekly (n=2) and 400mg once weekly (n=1). Plasma imatinib level was measured 24 hours after the last drug intake in 7 patients treated in once weekly schedule and it remained extremely low, ranging between 44–167 ng/ml. Molecular studies performed at the same time points confirmed molecular remission. With a median follow-up of 40 months all patients remained in CHR and FIP1L1-PDGFRA expression was undetectable in all treated patients. These data indicate that even very low imatinib doses are highly effective in remission maintenance of patients with F/P-positive CEL. Disclosures: No relevant conflicts of interest to declare.