Zadie Davis

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial

BACKGROUND Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine. METHODS 777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610. FINDINGS There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival. INTERPRETATION Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

ZAP-70 expression and prognosis in chronic lymphocytic leukaemia

BACKGROUND Chronic lymphocytic leukaemia (CLL) is a heterogeneous disease; many patients never need treatment, whereas some have poor outcomes. New treatments, which can induce complete remissions, allow patients with poor outlook to be treated while they are still asymptomatic. Whether or not the IgVH gene is mutated is the best predictor of clinical outcome, but this assay is unsuited to the routine laboratory. The gene coding for ZAP-70, a tyrosine kinase protein normally expressed in T and NK cells, has been shown by gene-expression profiling to be differentially expressed between patients with mutated and unmutated IgVH genes. We assessed whether ZAP-70 could be used as a prognostic marker in CLL. METHODS We developed a flow cytometry assay for ZAP-70 protein expression and investigated its concordance with ZAP-70 mRNA expression, IgVH gene mutational status, and clinical outcome in 167 patients with CLL. FINDINGS We showed high concordance between ZAP-70 protein expression and IgVH gene mutations. 108 patients (65%) had mutated IgVH genes and were ZAP-70 negative; 46 (28%) had unmutated IgVH genes and were ZAP-70 positive. Findings were discordant in 13 patients: six (4%) had mutated IgVH genes but were ZAP-70 positive, and seven (4%) had unmutated IgVH genes and were ZAP-70 negative. Expression of mRNA showed 97% concordance with ZAP-70 protein. Median survival was 24.4 years (95% CI 15.1-33.8) in ZAP-70 negative patients and 9.3 years (7.0-11.5) in those who were ZAP-70 positive (hazard ratio 5.5, 2.8-.8). INTERPRETATION ZAP-70 protein, which can be measured by flow cytometry in the general laboratory, is a reliable prognostic marker in CLL, equivalent to that of IgVH gene mutational status.

Recurrent mutations refine prognosis in chronic lymphocytic leukemia

Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%). BIRC3 mutations (2.5%) were associated with unmutated IGHV genes (U-CLL), del(11q) and trisomy 12, whereas MYD88 mutations (2.2%) were exclusively found among M-CLL. NOTCH1, SF3B1 and TP53 exhibited variable frequencies and were mostly enriched within clinically aggressive cases. Interestingly, as the timespan between diagnosis and mutational screening increased, so too did the incidence of SF3B1 mutations; no such increase was observed for NOTCH1 mutations. Regarding the clinical impact, NOTCH1 mutations, SF3B1 mutations and TP53 aberrations (deletion/mutation, TP53ab) correlated with shorter time-to-first-treatment (P<0.0001) in 889 treatment-naive Binet stage A cases. In multivariate analysis (n=774), SF3B1 mutations and TP53ab along with del(11q) and U-CLL, but not NOTCH1 mutations, retained independent significance. Importantly, TP53ab and SF3B1 mutations had an adverse impact even in U-CLL. In conclusion, we support the clinical relevance of novel recurrent mutations in CLL, highlighting the adverse impact of SF3B1 and TP53 mutations, even independent of IGHV mutational status, thus underscoring the need for urgent standardization/harmonization of the detection methods.

Cytogenetic aberrations and their prognostic value in a series of 330 splenic marginal zone B-cell lymphomas: a multicenter study of the Splenic B-Cell Lymphoma Group.

We conducted a retrospective collaborative study to cytogenetically characterize splenic marginal zone lymphoma (SMZL) and ascertain the prognostic value of chromosomal aberrations. Of 330 cases, 72% displayed an aberrant karyotype, 53% were complex, and 29% had a single aberration. The predominant aberrations were gains of 3/3q and 12q, deletions of 7q and 6q and translocations involving 8q/1q/14q. CD5 expression was detected in 39 of 158 cases (25%). The cytogenetic makeup of the CD5(+) group differed significantly from that of the CD5(-) group. Cases with unmutated IGHV were significantly associated with deletions of 7q and TP53. A strong association was noted between usage of the IGVH1-2 and deletion 7q, 14q alterations, and abnormal karyotype. On univariate analysis, patients with more than or equal to 2 aberrations, 14q alterations, and TP53 deletions had the shortest survival; 7q deletion did not affect survival. On multivariate analysis, cytogenetic aberrations did not retain prognostic significance; the parameters negatively affecting survival were hemoglobin and age. In conclusion, the cytogenetic profile of SMZL is distinct from other B-cell lymphomas. Complexity of the karyotype, 14q aberrations, and TP53 deletions are poor prognostic indicators and may be considered together with other clinicobiologic parameters to ascertain the prognosis of SMZL.

DLEU2, frequently deleted in malignancy, functions as a critical host gene of the cell cycle inhibitory microRNAs miR-15a and miR-16-1

The microRNAs miR-15a and miR-16-1 are downregulated in multiple tumor types and are frequently deleted in chronic lymphocytic leukemia (CLL), myeloma and mantle cell lymphoma. Despite their abundance in most cells the transcriptional regulation of miR-15a/16-1 remains unclear. Here we demonstrate that the putative tumor suppressor DLEU2 acts as a host gene of these microRNAs. Mature miR-15a/miR-16-1 are produced in a Drosha-dependent process from DLEU2 and binding of the Myc oncoprotein to two alterative DLEU2 promoters represses both the host gene transcript and levels of mature miR-15a/miR-16-1. In line with a functional role for DLEU2 in the expression of the microRNAs, the miR-15a/miR-16-1 locus is retained in four CLL cases that delete both promoters of this gene and expression analysis indicates that this leads to functional loss of mature miR-15a/16-1. We additionally show that DLEU2 negatively regulates the G1 Cyclins E1 and D1 through miR-15a/miR-16-1 and provide evidence that these oncoproteins are subject to miR-15a/miR-16-1-mediated repression under normal conditions. We also demonstrate that DLEU2 overexpression blocks cellular proliferation and inhibits the colony-forming ability of tumor cell lines in a miR-15a/miR-16-1-dependent way. Together the data illuminate how inactivation of DLEU2 promotes cell proliferation and tumor progression through functional loss of miR-15a/miR-16-1.

Prognostic factors identified three risk groups in the LRF CLL4 trial, independent of treatment allocation

Background Many prognostic markers have been identified in chronic lymphocytic leukemia, but there have been few opportunities to assess their relative importance in a large randomized trial. The aim of this study was to determine which of the available markers independently predicted outcome in patients requiring treatment and to use these to define new risk groups. Design and Methods A broad panel of clinical and laboratory markers, measured at randomization in patients entering the LRF CLL4 trial, was assessed with respect to treatment response, progression-free and overall survival, at a median follow-up of 68 months. Results Using the factors identified as independent predictors for progression-free survival, patients were subdivided into three risk groups: 6% had poor risk with known TP53 loss of greater than 10%; 72% had an intermediate risk without TP53 loss (≤10%) and with at least one of: unmutated IGHV genes and/or IGHV3-21 usage, 11q deletion, β-2 microglobulin greater than 4 mg/L; 22% had a good risk (with none of the above and mutated IGHV genes). The 5-year progression-free survival rates for these three groups were 0%, 12% and 34%, respectively, and the corresponding 5-year overall survival rates were 9%, 53% and 79% (both P<0.00005 independent of treatment allocation). In the intermediate risk group 250 patients, with data for all three risk factors, were further subdivided into intermediate-low (one risk factor) or intermediate-high (2 or 3 risk factors). The 5-year progression-free survival rates were 18% and 7% (P=0.0001) and the 5-year overall survival rates were 68% and 40% (P<0.00005), respectively. Conclusions This study demonstrates the role of biomarkers in prognosis and shows that, in patients requiring treatment, disease stage may no longer be an independent predictor of outcome. If validated independently, the risk groups defined here may inform the design of future trials in chronic lymphocytic leukemia. (Clinicaltrials.gov identifier: NCT00004218; controlled-trials.com identifier ISRCTN58585610).

Biallelic ATM Inactivation Significantly Reduces Survival in Patients Treated on the United Kingdom Leukemia Research Fund Chronic Lymphocytic Leukemia 4 Trial

PURPOSE The prognostic significance of ATM mutations in chronic lymphocytic leukemia (CLL) is unclear. We assessed their impact in the context of a prospective randomized trial. PATIENTS AND METHODS We analyzed the ATM gene in 224 patients treated on the Leukemia Research Fund Chronic Lymphocytic Leukemia 4 (LRF-CLL4) trial with chlorambucil or fludarabine with and without cyclophosphamide. ATM status was analyzed by denaturing high-performance liquid chromatography and was related to treatment response, survival, and the impact of TP53 alterations for the same patient cohort. RESULTS We identified 36 ATM mutations in 33 tumors, 16 with and 17 without 11q deletion. Mutations were associated with advanced disease stage and involvement of multiple lymphoid sites. Patients with both ATM mutation and 11q deletion showed significantly reduced progression-free survival (median, 7.4 months) compared with those with ATM wild type (28.6 months), 11q deletion alone (17.1 months), or ATM mutation alone (30.8 months), but survival was similar to that in patients with monoallelic (6.7 months) or biallelic (3.4 months) TP53 alterations. This effect was independent of treatment, immunoglobulin heavy chain variable gene (IGHV) status, age, sex, or disease stage. Overall survival for patients with biallelic ATM alterations was also significantly reduced compared with those with ATM wild type or ATM mutation alone (median, 42.2 v 85.5 v 77.6 months, respectively). CONCLUSION The combination of 11q deletion and ATM mutation in CLL is associated with significantly shorter progression-free and overall survival following first-line treatment with alkylating agents and purine analogs. Assessment of ATM mutation status in patients with 11q deletion may influence the choice of subsequent therapy.

A subset of Binet stage A CLL patients with TP53 abnormalities and mutated IGHV genes have stable disease

TP53 abnormalities consistently emerge as the most significant adverse prognostic factor in multivariate analyses of both prospective and retrospective studies in early and advanced chronic lymphocytic leukaemia (CLL).1 In view of the higher response rates often achieved with alemtuzumab-containing regimens compared with alkylating agent and/or purine analogue therapy2 and the possibility of long-term disease-free survival following allogeneic transplantation in some patients, there is an increasing consensus for screening for TP53 abnormalities in CLL patients who fulfil the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) recommendations for initiating therapy.

Immunogenetic analysis of the immune response to pneumococcal polysaccharide

Pneumococcal serotype‐specific anti‐capsular polysaccharide antibodies protect against invasive pneumococcal disease. Within an individual the diversity of these antibodies is limited. To evaluate the repertoire of antibodies to pneumococcus and determine whether oligoclonality is seen both between serotypes and between individuals, we sampled the B cell repertoire induced by polysaccharide and conjugate vaccine in adult volunteers. Fifteen hybridomas secreting pneumococcus‐specific monoclonal antibodies were generated from five volunteers. Ten were isotype switched, six were IgG2 and four were IgA. These included two isotype switch variants of the same clone. VH3 and Vκ2 were used by 10 / 15 and 7 / 13 of the sequenced clones, respectively, with identical genes, VH3 – 48 and Vκ2‐A17 used by a number of volunteers to a variety of serotypes. VDJ junctional characteristics and complementarity‐determining region (CDR) 3 length were variable. High levels of somatic mutation in CDR1 and 2, inconsistent with a primary response, were found in 10 / 11 of the isotype‐switched antibodies, including those induced by plain polysaccharide antigens. These data suggest that wild‐type infection or nasopharyngeal carriage of Streptococcus pneumoniae in adults may induce memory and the response to subsequent immunization with plain polysaccharide or conjugate pneumococcal vaccines may have the characteristics of a secondary response.

Over 30% of patients with splenic marginal zone lymphoma express the same immunoglobulin heavy variable gene: ontogenetic implications

We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele (*)04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2(*)04 peaked at 31%. The IGHV1-2(*)04 rearrangements carried significantly longer complementarity-determining region-3 (CDR3) than all other cases and showed biased IGHD gene usage, leading to CDR3s with common motifs. The great majority of analyzed rearrangements (299/345, 86.7%) carried IGHV genes with some impact of somatic hypermutation, from minimal to pronounced. Noticeably, 75/79 (95%) IGHV1-2(*)04 rearrangements were mutated; however, they mostly (56/75 cases; 74.6%) carried few mutations (97-99.9% germline identity) of conservative nature and restricted distribution. These distinctive features of the IG receptors indicate selection by (super)antigenic element(s) in the pathogenesis of SMZL. Furthermore, they raise the possibility that certain SMZL subtypes could derive from progenitor populations adapted to particular antigenic challenges through selection of VH domain specificities, in particular the IGHV1-2(*)04 allele.