Targeted next-generation sequencing identifies clinically relevant mutations in patients with chronic neutrophilic leukemia at diagnosis and blast crisis

Purpose. Chronic neutrophilic leukemia is a rare form of myeloproliferative neoplasm characterized by mature neutrophil hyperleukocytosis. The majority of patients harbor somatic mutations of CSF3R gene and are potentially amenable to targeted therapy with JAK inhibitors. The incidence and clinical significance of additional mutations requires clarification. Materials and methods. A next-generation sequencing approach for myeloid malignancy-associated mutations was applied to diagnostic and matched blast crisis samples from four chronic neutrophilic leukemia patients. Results. Next-generation sequencing confirmed the CSF3R T618I in all patients with identification of concurrent SRSF2, SETBP1, NRAS and CBL mutations at diagnosis. At blast crisis, clonal evolution was evidenced by an increased CSF3R T618I allele frequency and by loss or acquisition of CBL and NRAS mutations. Conclusion. The diagnostic utility of a targeted next-generation sequencing approach was clearly demonstrated with the identification of additional mutations providing the potential for therapeutic stratification of chronic neutrophilic leukemia patients (AU)

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Targeted next-generation sequencing identifies clinically relevant mutations in patients with chronic neutrophilic leukemia at diagnosis and blast crisis.

PURPOSE: Chronic neutrophilic leukemia is a rare form of myeloproliferative neoplasm characterized by mature neutrophil hyperleukocytosis. The majority of patients harbor somatic mutations of CSF3R gene and are potentially amenable to targeted therapy with JAK inhibitors. The incidence and clinical significance of additional mutations requires clarification. MATERIALS AND METHODS: A next-generation sequencing approach for myeloid malignancy-associated mutations was applied to diagnostic and matched blast crisis samples from four chronic neutrophilic leukemia patients. RESULTS: Next-generation sequencing confirmed the CSF3R T618I in all patients with identification of concurrent SRSF2, SETBP1, NRAS and CBL mutations at diagnosis. At blast crisis, clonal evolution was evidenced by an increased CSF3R T618I allele frequency and by loss or acquisition of CBL and NRAS mutations. CONCLUSION: The diagnostic utility of a targeted next-generation sequencing approach was clearly demonstrated with the identification of additional mutations providing the potential for therapeutic stratification of chronic neutrophilic leukemia patients.

Transformed follicular lymphoma (tFL): consolidation therapy may improve survival.

PURPOSE: Retrospective study to evaluate the outcome of patients with transformed follicular lymphoma (tFL) treated with rituximab-containing chemotherapy and consolidation. PATIENTS AND METHODS: Patients diagnosed with tFL from 2003 to 2013 treated with consolidation therapy with last follow-up in December 2015 were identified from the institutional lymphoma database and included in this study. Data collected included age, gender, stage, interval to tFL diagnosis, R-IPI score, histological diagnosis and therapy. The treatment algorithm used was stratified for age, performance status (PS) and sibling donor availability using R-chemotherapy induction followed by consolidation with allogeneic stem cell transplant (SCT), autologous SCT, Zevalin or rituximab maintenance (RM). Patients with B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and Burkitt's lymphoma (BCL-U), with FISH-proven t(14;18) and t(8;14) and their variants were excluded. RESULTS: Four hundred patients were diagnosed with FL of whom 26 (7%) developed histologically proven tFL. The group was predominantly male (73%) with a median age at transformation of 53 (range 27-72) years and 85% presented with stage III/IV disease. Thirteen (50%) patients presented with de novo tFL and the remainder had previously diagnosed FL, with a median time to transformation of 5.7 (range 1-15) years. The median follow-up time from tFL diagnosis to December 2015 is 8 (range 4-14) years. All patients received immuno-chemotherapy achieving an overall response rate (ORR) of 100%. Fourteen (54%), patients were transplant eligible and based on donor availability, six had an auto-SCT only, five had an allo-SCT only and three had a matched unrelated allo-SCT for a post-auto-SCT relapse. The 12 patients (46%) who were not transplant eligible were consolidated with rituximab maintenance (RM) in nine (35%) and Zevalin in three (11%) cases. The overall survival (OS) and progression-free survival (PFS) for the series at 5 years were, 92 and 73%, respectively. CONCLUSION: This consecutively treated series of 26 patients with tFL have had a better outcome than expected which may be due to the use of rituximab-chemotherapy and a consolidation strategy based on age, PS and availability of a sibling donor.

Treatment-free remission following frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the ENESTfreedom study.

The single-arm, phase 2 ENESTfreedom trial assessed the potential for treatment-free remission (TFR; i.e., the ability to maintain a molecular response after stopping therapy) following frontline nilotinib treatment. Patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase with MR4.5 (BCR-ABL1⩽0.0032% on the International Scale (BCR-ABL1IS)) and ⩾2 years of frontline nilotinib therapy were enrolled. Patients with sustained deep molecular response during the 1-year nilotinib consolidation phase were eligible to stop treatment and enter the TFR phase. Patients with loss of major molecular response (MMR; BCR-ABL1IS⩽0.1%) during the TFR phase reinitiated nilotinib. In total, 215 patients entered the consolidation phase, of whom 190 entered the TFR phase. The median duration of nilotinib before stopping treatment was 43.5 months. At 48 weeks after stopping nilotinib, 98 patients (51.6%; 95% confidence interval, 44.2-58.9%) remained in MMR or better (primary end point). Of the 86 patients who restarted nilotinib in the treatment reinitiation phase after loss of MMR, 98.8% and 88.4%, respectively, regained MMR and MR4.5 by the data cutoff date. Consistent with prior reports of imatinib-treated patients, musculoskeletal pain-related events were reported in 24.7% of patients in the TFR phase (consolidation phase, 16.3%).

Burkitt leukaemia/lymphoma: R-CODOX-M/R-IVAC remains gold standard treatment in BL.

BACKGROUND: Sporadic Burkitt lymphoma (BL), characterised by translocation-associated C-MYC upregulation is a rare, aggressive lymphoma with a cure rate up to 90 % using the R-CODOX-M/R-IVAC (RCRI) protocol. RCRI is active in HIV-associated BL in combination with HAART. The WHO classification system defines lymphomas intermediate between DLBCL and BL, in which lymphomas with t(14;18)(q32;q21) and C-MYC-carrying translocation, i.e. 'double-hit' are included (BL-DH), and these patients are conventionally treated with RCRI. RESULT: We describe the SJH experience of 25 patients with BL, BL + HIV and BL-DH treated with RCRI between 2002 and 2011. Twelve BL patients (8M/4F), median age 49.1 years (range 20-73 years); of whom 9 had extensive disease, including 8 with marrow and 2 with CNS involvement. Eleven patients remain in remission at 80.5 months (range 37-147 months) from completion of treatment and one died of progressive BL giving an OS of 91.6 % at 1 year with no late relapses. Eight patients with BL + HIV were treated (6M/2F) with a median age 40.25 years (range 24-64). Five remain in complete remission (CR) at 65 months (range 13-109 months), three patients died, two of progressive disease and one of treatment-associated hepatotoxicity in CR. Five patients with BL-DH were included; (3M/2F), age 47.8 years (range 42-55 years); and all patients died of progressive disease, 4 on RCRI therapy and a further patient despite an allogeneic transplantation. CONCLUSION: These results confirm that RCRI is an effective treatment in adults with BL and BL + HIV and remains the gold standard against which other regimens should be compared. We confirm the poor prognosis found in BL-DH, indicating new treatment approaches are needed for this sub-group which should be identified at diagnosis by FISH analysis.

BK virus (BKV) plasma dynamics in patients with BKV-associated hemorrhagic cystitis following allogeneic stem cell transplantation.

INTRODUCTION: The use of real-time polymerase chain reaction testing in the investigation of BK virus (BKV)-associated disease has been widely studied in renal transplant recipients; however, far less research has been done in this area with respect to the plasma BK viral load dynamics of BKV hemorrhagic cystitis (BKV-HC) in hematopoietic stem cell transplant recipients. AIM: The aim of this study was to examine the BK viral load dynamics in plasma samples collected from patients post transplant who had laboratory-confirmed BKV-HC. METHODS: Patients who developed BK viremia were compared with patients who did not develop viremia, and a statistical comparison of risk factors for viremia was performed. Seventeen patients were included in this study. Urine samples from the day of BKV diagnosis were available in 13 of the 17 cases. In total, 154 archived plasma samples from around the time of the BKV-HC event were also included in the study from these 17 patients. RESULTS: The median time from transplantation to the onset of detectable viremia was 68 days. The median viral load in the 13 urine samples was 1.8 × 10(8) copies/mL, which was significantly higher than the median viral load in the 38 positive plasma samples of 6.6 × 10(2) copies/mL (Mann-Whitney test, U = 16, P < 0.001). CONCLUSION: The lymphocyte count on the day of the positive BKV test was significantly lower in patients with BKV viremia than in patients with no viremia (P = 0.02) and also the white cell and platelet counts were lower on the day of the first positive BKV test. Although there is not inter-patient consistency as regards correlation between urinary BK viral loads and severity of clinical BKV-HC, in individual patients the decline in viral load in plasma did correlate with clinical recovery.

Correlation of the BRAF V600E mutation in hairy cell leukaemia with morphology, cytochemistry and immunophenotype.

Hairy cell leukaemia (HCL) has distinct clinical, morphological and immunophenotypic features with no recurrent cytogenetic or molecular abnormalities reported until the recent description of the BRAF V600E mutation in patients with classical HCL. The incidence of this mutation was sought in 27 patients with either classical HCL or HCL variant by an allele-specific PCR approach and findings related to morphology, cytochemistry and immunophenotype. A high degree of correlation was noted between the presence of BRAF V600E and established diagnostic criteria in 26/27 patients with HCL/HCL variant. Detection of the BRAF V600E mutation is therefore a useful adjunct in the differential diagnosis of HCL and HCL variant and highlights the value of a multifaceted approach to the diagnosis of this malignancy.

Incidence and significance of FLT3-ITD and NPM1 mutations in patients with normal karyotype acute myeloid leukaemia.

BACKGROUND: Acute myeloid leukaemia (AML) is a heterogeneous clonal disorder of haematopoietic progenitor cells. Approximately half of all adult AML patients have a normal karyotype (NK-AML) and an intermediate risk prognosis. AIMS: To determine the incidence and prognostic significance of NPM1 and FLT3-ITD mutations in a population of patients with NK-AML. METHODS: FLT3-ITD and NPM1 mutation status was retrospectively sought in presentation samples from 44 NK-AML patients. RESULTS: FLT3-ITD and NPM1 mutations were detected in 45.5 and 54.5% of patients, respectively, allowing stratification according to genotype. CONCLUSIONS: FLT3-ITD and NPM1 mutation status can be defined in NK-AML. Prospective screening for these mutations is advocated in all NK-AML patients, as the genotype is of clinical importance when considering treatment options including stem cell transplantation.

Novel pyrrolo-1,5-benzoxazepine compounds display significant activity against resistant chronic myeloid leukaemia cells in vitro, in ex vivo patient samples and in vivo.

BACKGROUND: Imatinib is a direct and potent inhibitor of the constitutively active tyrosine kinase, breakpoint cluster region-Abelson (Bcr-Abl), which is central to the pathogenesis of chronic myeloid leukaemia (CML) patients. As such, imatinib has become the front-line treatment for CML patients. However, the recent emergence of imatinib resistance, commonly associated with point mutations within the kinase domain, has led to the search for alternative drug treatments and combination therapies for CML. METHODS: In this report, we analyse the effects of representative members of the novel pro-apoptotic microtubule depolymerising pyrrolo-1,5-benzoxazepines or PBOX compounds on chemotherapy-refractory CML cells using a series of Bcr-Abl mutant cell lines, clinical ex vivo patient samples and an in vivo mouse model. RESULTS: The PBOX compounds potently reduce cell viability in cells expressing the E225K and H396P mutants as well as the highly resistant T315I mutant. The PBOX compounds also induce apoptosis in primary CML samples including those resistant to imatinib. We also show for the first time, the in vivo efficacy of the pro-apoptotic PBOX compound, PBOX-6, in a CML mouse model of the T315I Bcr-Abl mutant. CONCLUSION: Results from this study highlight the potential of these novel series of PBOX compounds as an effective therapy against CML.

Fludarabine, Cyclophosphamide and Rituximab: an effective chemoimmunotherapy combination with high remission rates for chronic lymphocytic leukaemia.

BACKGROUND: Combined Fludarabine and Cyclophosphamide is now standard first-line therapy in chronic lymphocytic leukaemia (CLL) and the addition of Rituximab improves outcome. METHODS: We adopted a modified Fludarabine, Cyclophosphamide and Rituximab (FCR) protocol in treating 39 patients (median age 57 years) with progressive or advanced CLL. Depending on CR, treatment was given for four or six cycles. RESULT: Twenty-six patients were treatment naïve and 13 were pre-treated. Twelve patients had progressive Binet stage A, 16 stage B and 11 stage C disease. The overall response rate (ORR) was 100%, with 75% achieving CR. Neutropenia was the major toxicity in 71/187 (38%) of the cycles. There were five deaths, two from infection and three from progressive disease. Twenty-six of 31 patients have maintained their post-treatment disease status for a median of 17 months (2-41). CONCLUSION: We conclude that FCR is a feasible, well-tolerated and effective treatment for patients with CLL.

Successful outcome of patients with relapsed/refractor Hodgkin lymphoma treated with high dose chemotherapy at the National Adult Bone Marrow Transplant Unit at St. James's Hospital.

Patients with Hodgkin lymphoma who relapse or are refractory to first line multi-agent chemotherapy can be successfully salvaged with high dose therapy (HDT) and autologous stem cell transplant (ASCT). Twenty-six patients with relapsed or refractory Hodgkin lymphoma have been treated with HDT and ASCT at St James Hospital between 2000 and 2005. At day 100 post HDT-ASCT, 23 patients were in complete remission. This group included all 6 patients transplanted at first relapse, 8 of 9 with advanced disease and 9 of 11 with primary refractory disease. Patients treated in first relapse had the best outcome with an overall and progression free survival of 100% (median, 37 months). Patients with primary refractory disease had the poorest outcome with an overall survival of 76% (median, 28 months). All patients with primary refractory disease responsive to salvage chemotherapy were in remission at a median of 28 months. The presence of chemosensitive disease prior to transplantation was the most important determinant of outcome. PET-CT imaging is useful to assess chemosensititvity prior to HDT and thus predict which patients will do well post HDT-ASCT. No patient died of treatment related toxicity. The outcome of this patient series compares favourably with international figures.

Incidence and significance of the JAK2 V617F mutation in patients with chronic myeloproliferative disorders.

BACKGROUND: The chronic myeloproliferative disorders (MPD) are clonal haemopoietic stem cell disorders. AIMS: The incidence of JAK2 V617F mutation was sought in a population of patients with MPD. METHODS: The JAK2 V617 mutation status was determined in 79 patients with known MPD and 59 patients with features suggestive of MPD. RESULTS: The mutation was found in patients with polycythaemia vera, essential thrombocythaemia, idiopathic myelofibrosis and in patients with other chronic myeloproliferative disorders. Eight JAK2 V617F positive cases were identified amongst those patients with features suggestive of MPD. CONCLUSIONS: The incidence of the JAK2 V617F mutation in MPD patients is similar to that reported by other groups. The assay confirmed and refined the diagnosis of several patients with features indicative of MPD. We suggest screening for this mutation in all patients with known and suspected MPD as identification is valuable in classification and is a potential target for signal transduction therapy.

Marrow aplasia developing 13 years after HLA-identical sibling allogeneic transplantation for chronic myeloid leukaemia: successful treatment with antithymocyte globulin and peripheral blood stem cell infusion from the original donor.

Secondary or late graft failure has been defined as the development of inadequate marrow function after initial engraftment has been achieved. We describe a case of profound marrow aplasia occurring 13 years after sibling allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) in first chronic phase. Although the patient remained a complete donor chimera, thereby suggesting that an unselected infusion of donor peripheral blood stem cells (PBSC) or bone marrow might be indicated, the newly acquired aplasia was thought to be immune in aetiology and some immunosuppression was therefore considered appropriate. Rapid haematological recovery was achieved after the infusion of unselected PBSC from the original donor following conditioning with anti-thymocyte globulin (ATG).

Myeloablative allografting for chronic lymphocytic leukemia: evidence for a potent graft-versus-leukemia effect associated with graft-versus-host disease.

In all, 30 patients with CLL proceeded to myeloablative allogeneic BMT using related (n=20, 67%) or unrelated (n=10) donors, at the Princess Margaret Hospital (Toronto) (n=20) or the Leukemia/BMT Program of BC (Vancouver) (n=10), from 1989 to 2001. Median (range) interval from diagnosis to BMT was 4.8 (0.3-13) years, median number of prior therapies was three and median age 48 years. The preparative regimen included total body irradiation in 15 (50%). In all, 14 of 30 patients (47%) are alive, with median (range) follow up of 4.3 (2.4-10.5) years. All are in complete remission, two following therapy for post-BMT progression. Actuarial overall (OS) and event-free survival (EFS) at 5 years is 39% (OS 48% for related donor and 20% for unrelated donor BMT); cumulative incidence of nonrelapse mortality (NRM) and relapse is 47 and 19%, respectively. Both acute (RR=0.008, P=0.01) and chronic (RR=0.006, P=0.02) Graft-versus-host disease (GVHD) were associated with markedly decreased risk of relapse. Patients receiving grafts from unrelated donors had increased NRM (RR=3.6, P=0.02) and decreased OS (RR of death=3.4, P=0.002). Allogeneic BMT has resulted in long-term EFS in approximately 40% of patients with CLL. There is evidence for a strong graft-versus-leukemia effect associated with acute and chronic GVHD, resulting in near complete protection from relapse.

Autologous stem cell transplantation in myeloma: the St James's Hospital experience, 1997-2003.

BACKGROUND: High-dose treatment with autologous stem cell transplantation (ASCT) has become the standard of care for patients with myeloma below the age of 65 years. AIMS: We report an audit of 60 patients (median age: 52.5 years) who underwent ASCT in the National Bone Marrow Transplant centre in St James's Hospital in Dublin between 1997 and 2003 inclusive. METHODS: Clinical and laboratory data were retrieved from patient medical records and hospital information management systems. RESULTS: Thirty-six patients had IgG, 11 IgA, 1 IgD, 9 light chain and 3 non-secretory MM. Fifty-seven (95%) patients received anthracycline-corticosteroid combination chemotherapy prior to autografting. There was no transplant-related mortality (TRM). Complete (CR) and Partial Responses (PR) were seen in 16 (29.6%) and 29 (53.7%) of those evaluable (n = 54 (90%)). The actuarial Progression-Free (PFS) and Overall Survival (OS) rates at five years are 13% and 55% respectively. CONCLUSION: Centre outcome is comparable to published international series and supports the use of ASCT in the treatment of this malignancy.