Search

Elderly chronic lymphocytic leukaemia (CLL) patients treated outside of trials have notably greater toxicity with the Brutons tyrosine kinase inhibitor ibrutinib compared to younger patients. It is not known whether the same holds true for the B-cell lymphoma 2 inhibitor venetoclax. We provide a comprehensive analysis of key safety measures and efficacy in 342 patients comparing age categories ≥75 and

Limited data exists to show the correlation of (tumour protein 53) TP53 mutation detected by Next generation sequencing (NGS) and the presence/absence of deletions of 17p13 detected by FISH. The study which is the largest series to date includes 2332 CLL patients referred for analysis of del(17p) by FISH and TP53 mutations by NGS before treatment. Using a 10% variant allele frequency (VAF) threshold, cases were segregated into high burden mutations (≥10%) and low burden mutations (<10%). TP53 aberrations (17p [del(17p)] and/or TP53 mutation) were detected in 320/2332 patients (13.7%). Using NGS analysis, 429 TP53 mutations were identified in 303 patients (13%). Of these 238 (79%) and 65 (21%) were cases with high burden and low burden mutations respectively. In our cohort, 2012 cases did not demonstrate a TP53 aberration (86.3%). A total of 159 cases showed TP53 mutations in the absence of del(17p) (49/159 with low burden TP53 mutations) and 144 cases had both TP53 mutation and del(17p) (16/144 with low burden mutations). Only 17/2332 (0.7%) cases demonstrated del(17p) with no TP53 mutation. Validated NGS protocols should be used in clinical decision making to avoid missing low-burden TP53 mutations and can detect the vast majority of TP53 aberrations. [ABSTRACT FROM AUTHOR]

Abstract Background Prognostic index for survival estimation by clinical-demographic variables were previously proposed in chronic lymphocytic leukemia (CLL) patients. Our objective was to test in a large retrospective cohort of CLL patients the prognostic power of biological and clinical-demographic variable in a comprehensive multivariate model. A new prognostic index was proposed. Methods Overall survival and time to treatment in 620 untreated CLL patients were analyzed retrospectively to evaluate the multivariate independence and predictive power of mutational status of immunoglobulin heavy chain variable gene segments (IGHV), high-risk chromosomal aberration such as 17p or 11q deletions, CD38 and ZAP-70 expression, age, gender, Binet stage, β2-microglobulin levels, absolute lymphocyte count and number of lymph node regions. Results IGHV mutational status and 17p deletion were the sole biological variables with independent prognostic relevance in a multivariate model for overall survival, which included easily measurable clinical parameters (Binet staging, β2-microglobulin levels) and demographics (age and gender). Analysis of time to treatment in Binet A patients below 70 years of age showed that IGHV was the most important predictor. A novel 6-variable clinical-biological prognostic index was developed and internally validated, which assigned 3 points for Binet C stage, 2 points/each for Binet B stage and for age > 65 years, 1 point/each for male gender, high β2-microglobulin levels, presence of an unmutated IGHV gene status or 17p deletion. Patients were classified at low-risk (score = 0-1; 21%), intermediate-risk (score 2-5; 63% of cases), high-risk (score 6-9; 16% of cases). Projected 5-year overall survival was 98%, 90% and 58% in low-, intermediate- and high-risk groups, respectively. A nomogram for individual patient survival estimation was also proposed. Conclusions Data indicate that IGHV mutational status and 17p deletion may be integrated with clinical-demographic variables in new prognostic tools to estimate overall survival.

Summary: Venetoclax is a BCL2 inhibitor with activity in relapsed/refractory (R/R) chronic lymphocytic leukaemia (CLL). We conducted a multi‐centre retrospective analysis of 105 R/R CLL patients who received venetoclax pre‐National Health Service commissioning. The median age was 67 years and median prior lines was 3 (range: 1–15). 48% had TP53 disruption. At ≥2 lines, 60% received a Bruton Tyrosine Kinase inhibitor (BTKi) and no prior phosphoinositide 3‐kinase inhibitor (Pi3Ki), 25% received a Pi3Ki and no prior BTKi, and 10% received both. Patients discontinued B cell receptor inhibitor (BCRi) because of toxicity in 44% and progression in 54%. Tumour lysis syndrome risk was low, intermediate or high in 27%, 25%, and 48% respectively. Overall response was 88% (30% complete response [CR]). The overall response rate was 85% (CR 23%) in BTKi‐exposed patients, 92% (CR 38%) in Pi3Ki‐exposed patients and 80% (CR 20%) in both (P = 0·59). With a median follow‐up of 15·6 months, 1‐year progression‐free survival was 65·0% and 1‐year overall survival was 75·1%. Dose reduction or temporary interruption did not result in an inferior progression‐free or discontinuation‐free survival. Risk of progression or death after stopping a prior BCRi for progression was double compared to those stopping for other reasons (predominantly toxicity) (Hazard Ratio 2·01 P = 0·05). Venetoclax is active and well tolerated in R/R CLL post ≥1 BCRi. Reason(s) for stopping BCRi influences venetoclax outcomes. [ABSTRACT FROM AUTHOR]

IGHV gene mutational status has prognostic significance in chronic lymphocytic leukaemia ( CLL) but the percentage of mutations that correlates best with clinical outcome remains controversial. We initially studied 558 patients from diagnosis and found significant differences in median time to first treatment ( TTFT) among Stage A patients and in overall survival ( OS) for the whole cohort, between cases with <97% and 97-98·99% identity and between cases with 97-98·99% and ≥99% identity, when cases from the IGHV3-21 Stereotype Subset #2 were excluded. A significant difference in progression-free survival (PFS) and OS between those with <97% and 97-98·99% identity, but not between those with 97-98·99% and ≥99% identity was also observed in a validation cohort comprising 460 patients in the UK CLL4 trial. Cox Regression analyses in the Stage A cohort revealed that a model which incorporated <97%, 97-98·99% and ≥99% identity as subgroups, was a better predictor of TTFT in CLL than using the 98% cut-off. Multivariate analysis selected the three mutational subgroups as independent predictors of TTFT in Stage A patients, and of OS in the diagnostic cohort. This study highlights that cases with 97% identity should not be considered to have the same prognosis as other cases with mutated IGHV genes defined as <98% identity to germline. [ABSTRACT FROM AUTHOR]

In a fraction of patients, chronic lymphocytic leukaemia ( CLL) can transform to Richter syndrome ( RS), usually a diffuse large B-cell lymphoma ( DLBCL). We studied genome-wide promoter DNA methylation in RS and clonally related CLL-phases of transformed patients, alongside de novo DLBCL (of non-germinal centre B type), untransformed- CLL and normal B-cells. The greatest differences in global DNA methylation levels were observed between RS and DLBCL, indicating that these two diseases, although histologically similar, are epigenetically distinct. RS was more highly methylated for genes involved in cell cycle regulation. When RS was compared to the preceding CLL-phase and with untransformed- CLL, RS presented a higher degree of methylation for genes possessing the H3 K27me3 mark and PRC2 targets, as well as for gene targets of TP53 and RB1. Comparison of the methylation levels of individual genes revealed that OSM, a stem cell regulatory gene, exhibited significantly higher methylation levels in RS compared to CLL-phases. Its transcriptional repression by DNA methylation was confirmed by 5-aza-2′deoxycytidine treatment of DLBCL cells, determining an increased OSM expression. Our results showed that methylation patterns in RS are largely different from de novo DLBCL. Stem cell-related genes and cell cycle regulation genes are targets of DNA methylation in RS. [ABSTRACT FROM AUTHOR]

Deletion on the long arm of chromosome 11 occurs in 5-20% of chronic lymphocytic leukaemia (CLL) patients. We analysed clinical-biological characteristics of 131 CLL patients carrying 11q deletion documented before therapy ( de novo 11q deleted CLL). De novo 11q deleted CLL were characterized by high frequencies of unmutated immunoglobulin variable heavy genes, multiple fluorescence in situ hybridization aberrations and lymph node involvement. Factors significantly associated with shorter time to first treatment (TTFT) were advanced Binet stages, high white blood cell count, increased β2-microglobulin levels, 17p in addition, splenomegaly and more extensive lymphadenopathy. We found that patients with <25% 11q deleted nuclei ( n = 22) experienced longer TTFT compared with patients with ≥25% 11q deleted nuclei ( n = 87; median TTFT, 40 vs. 14 months, p = 0.011) and also showed better response to treatments (complete response, 50% vs. 21%, p = 0.016). The variables identified by multivariate analysis as independently associated with reduced TTFT were advanced Binet stages [hazard ratio (HR) 4.69; p < 0.001] and ≥25% 11q deleted nuclei (HR 4.73; p = 0.004). De novo 11q deleted CLLs exhibit variable clinical outcome. The percentage of deleted nuclei inside leukemic clone should be included in the prognostic definition of therapy-naïve 11q deleted CLL patients. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents a study on 605 patients with chronic lymphocytic leukemia (CLL) focusing on the impact of NOTCH1 and SFB3 mutations on the risk of transformation of CLL to Richter syndrome (RS). Techniques like Sanger sequencing, flow cytometry and multivariate analysis were used during the study. The SFB3 mutations showed no impact on RS development and were absent in all the CLL patients. 40 to 50 percent of NOTCH1 mutated patients developed RS.

Several appendixes are presented depicting clinical and biological characteristics of patients with chronic lymphocytic leukaemia and Tp53 disfunction.

The immunoglobulin heavy chain variable gene ( IGHV) mutational status has been recognized as an important predictor of prognosis in chronic lymphocytic leukaemia (CLL) since 1999. More recently, other features of the B-cell receptor, such as stereotypy, have been identified as capable of refining the prognostic potential of IGHV status in the clinical assessment of CLL patients. In this context, different genes belonging to the IGHV3 subgroup, the most frequently used subgroup in CLL, have been shown to denote disease subsets that either display a bad prognosis (i.e. IGHV3-21, IGHV3-23) or are associated with particularly good clinical outcomes, including a highly stable/indolent clinical course, even prone to spontaneous regression (i.e. IGHV3-72, IGHV3-30). The present review focuses on the molecular and biological features of CLL-expressing specific genes belonging to the IGHV3 subgroup that are known to mark disease subsets with completely different clinical courses, and may be possibly related to CLL pathogenesis via antigen and/or superantigen involvement. [ABSTRACT FROM AUTHOR]

Richter syndrome (RS) represents the transformation of chronic lymphocytic leukaemia (CLL) to aggressive lymphoma. Risk factors of CLL transformation to RS are only partly known. We explored the role of the host genetic background as a risk factor for RS occurrence. Forty-five single nucleotide polimorphisms (SNPs) known to be relevant for CLL prognosis were genotyped in a consecutive cohort of 331 CLL, of which 21 had transformed to RS. After correcting for multiple testing and adjusting for previously reported RS risk factors, the LRP4 rs2306029 TT variant genotype was the sole SNP independently associated with a higher risk of RS transformation (Hazard Ratio: 4·17; P = 0·001; q = 0·047). The enrichment of LRP4 TT genotype in RS was confirmed in an independent series ( n = 44) used for validation purposes. The LRP4 protein was expressed in CLL ( n = 66). Bioinformatic analysis scored LRP4 rs2306029 as a variant with possible deleterious and damaging variant of LRP4. LRP4 genotyping may help the recognition of patients with increased risk of RS at the time of CLL diagnosis. [ABSTRACT FROM AUTHOR]

Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic monoclonal expansion of <5·0 × 109/l circulating CLL-phenotype B-cells. The relationship between MBL and Rai 0 CLL, as well as the impact of biological risk factors on MBL prognosis, are unknown. Out of 460 B-cell expansions with CLL-phenotype, 123 clinical MBL (cMBL) were compared to 154 Rai 0 CLL according to clinical and biological profile and outcome. cMBL had better humoral immune capacity and lower infection risk, lower prevalence of del11q22-q23/del17p13 and TP53 mutations, slower lymphocyte doubling time, and longer treatment-free survival. Also, cMBL diagnosis was a protective factor for treatment risk. Despite these favourable features, all cMBL were projected to progress, and lymphocytes <1·2 × 109/l and >3·7 × 109/l were the best thresholds predicting the lowest and highest risk of progression to CLL. Although IGHV status, CD38 and CD49d expression, and fluorescence in situ hybridization (FISH) karyotype individually predicted treatment-free survival, multivariate analysis identified the presence of +12 or del17p13 as the sole independent predictor of treatment requirement in cMBL (Hazard ratio: 5·39, 95% confidence interval 1·98–14·44, P = 0·001). Overall, these data showed that cMBL has a more favourable clinical course than Rai 0 CLL. Given that the biological profile can predict treatment requirement, stratification based on biological prognosticators may be helpful for cMBL management. [ABSTRACT FROM AUTHOR]

A fraction of chronic lymphocytic leukaemia (CLL) cases carry highly homologous B-cell receptors (BCR), i.e. characterized by non-random combinations of immunoglobulin heavy-chain variable ( IGHV) genes and heavy-chain complementarity determining region-3 (HCDR3), often associated with a restricted selection of IGVK/L light chains. Such ‘stereotyped’ BCR occur more frequently in CLL with unmutated (UM) than mutated (M) IGHV genes. We analysed 1426 IG rearrangements (from 1398 CLL cases) by a clustering driven by HCDR3 similarities. Molecular findings were correlated to time-to-treatment (TTT) and presence of known prognosticators. Sixty-nine clusters (319 IG-rearrangements, 22·4%) with stereotyped BCR were identified. Among 30 confirmed clusters (≥3 IG-rearrangements/cluster), we found 14 novel clusters, of which 11 had M IG rearrangements (M clusters) and predominantly (8/11) used IGHV3 subgroup genes. Recurrent cluster-biased amino acid changes were found throughout IGHV sequences of these ‘M clusters’. Regarding clinical outcome: (i) UM CLL from the IGHV1-2/1-3/1-18/1-46/7-4-1/IGKV1-39 cluster had poorer prognosis than UM/M cases, or UM cases using the same IGHV genes but not in clusters; (ii) M CLL from the IGHV3-21/IGLV3-21 cluster had TTT similar to UM CLL, and shorter than M CLL expressing IGHV3-21 but not in cluster. Altogether, our analysis identified additional molecular and clinical features for CLL expressing stereotyped BCR. [ABSTRACT FROM AUTHOR]

Deletion of 17p ( TP53) identifies a rare subset of chronic lymphocytic leukaemia (17p- CLL) with aggressive behaviour. Genome-wide DNA-profiling was performed to investigate 18 patients with 17p- CLL. All cases had multiple copy-number (CN) changes. Among the several recurrent CN changes identified, 8q24.13-q24.1-gain ( MYC), 8p-loss ( TNFRSF10A/B, also known as TRAIL1/2) and 2p16.1-p14-gain ( REL/BCL11A) appeared frequently represented. 8p-loss and 2p16.1-p14-gain also appeared clinically relevant and predicted significant shorter time from diagnosis to treatment (8p-loss) and overall survival (8p-loss and 2p16.1-p14-gain, P < 0·05). These observations document a highly unstable genome in 17p- CLL and suggest that additional genes outside the TP53 locus may be important for tumour behaviour. [ABSTRACT FROM AUTHOR]

Immunophenotypic studies, fluorescence in situ hybridization (FISH) and conventional karyotyping were used to define the clinicobiological significance of 14q32 translocations involving the immunoglobulin gene locus (14q32/ IGH) in 252 chronic lymphocytic leukaemia (CLL) patients. The following regions were studied: 13q14, centromere 12, 6q21; 11q22/ ATM; 17p13/ TP53, 14q32/ IGH. Patients were classified as group 1 (favourable, i.e. 13q-single or normal), group 2 (intermediate risk, i.e. +12, 6q-, 1–2 anomalies), group 3 (unfavourable, i.e. 17p-, 11q-, complex karyotype), or group 4 (14q32/ IGH translocation). Endpoints were treatment-free survival (TFS) and overall survival (OS). One hundred and ten patients were included in group 1, 99 in group 2, 25 in group 3 and 18 in group 4. 14q32/ IGH translocation partners were identified in eight cases ( BCL2 in five cases, BCL11A, CCND3 and CDK6 in one case each). group 4 showed shorter TFS versus groups 2 and 1 (25% patients treated at 2 months vs. 12 ( P = 0·02) and 20 months ( P = 0·002), respectively) and shorter OS (25% patients dead at 18 months versus 50 ( P = 0·0003) and >60 months ( P < 0·0001) respectively. The 14q32/ IGH translocation maintained prognostic significance at multivariate analysis on TFS ( P = 0·025) and OS ( P < 0·001), along with advanced stage and CD38+. These findings show that the 14q32/ IGH translocation predicts for an unfavourable outcome in CLL and that this cytogenetic subset might be included as a separate entity in a hierarchical cytogenetic classification of CLL. [ABSTRACT FROM AUTHOR]

BTK inhibitors (BTKi) have dramatically improved outcomes for patients with chronic lymphocytic leukaemia (CLL) and some forms of B-cell lymphoma. However, new strategies are needed to enhance responses. Here we have performed a detailed analysis of the effects of BTKi on B-cell receptor (BCR)-induced signalling using primary malignant cells from CLL patients and B-lymphoma cell lines. Although BTK is considered as a key activator of PLCγ2, BTKi (ibrutinib and acalabrutinib) failed to fully inhibit calcium responses in CLL samples with strong BCR signalling capacity. This BTKi-resistant calcium signalling was sufficient to engage downstream calcium-dependent transcription and suppress CLL cell apoptosis and was entirely independent of BTK and not just its kinase activity as similar results were obtained using a BTK-degrading PROTAC. BTK-independent calcium signalling was also observed in two B-lymphoma cell lines where BTKi had little effect on the initial phase of the calcium response but did accelerate the subsequent decline in intracellular calcium. In contrast to BTKi, calcium responses were completely blocked by inhibition of SYK in CLL and lymphoma cells. Engagement of BTK-independent calcium responses was associated with BTK-independent phosphorylation of PLCγ2 on Y753 and Y759 in both CLL and lymphoma cells. Moreover, in CLL samples, inhibition of RAC, which can mediate BTK-independent activation of PLCγ2, cooperated with ibrutinib to suppress calcium responses. BTK-independent calcium signalling may limit the effectiveness of BTKi to suppress BCR signalling responses and our results suggest inhibition of SYK or dual inhibition of BTK and RAC as alternative strategies to strengthen pathway blockade. • Efficacy of BTKi against BCR-induced Ca2+ responses varies between CLL samples • BTK-independent signals can promote CLL cell survival and transcriptional responses • BTK-independent Ca2+ responses are associated with retained PLCγ2 phosphorylation • RAC inhibition and ibrutinib cooperate to suppress Ca2+ responses in CLL cells [ABSTRACT FROM AUTHOR]