Prognostic factors and risk stratification in chronic lymphocytic leukemia

An overview of prognostic markers in patients with CLL

Chronic lymphocytic leukemia (CLL) is a low-grade B-cell lymphoproliferative disorder. It is the most prevalent type of leukemia in the western countries, with a median age at diagnosis of 70 years. In 2023, it is estimated that there will be 18,740 new cases of CLL, and an estimated 4,490 people will die of this disease. It represents 1.0% of all new cancer cases in the U.S. The rate of new cases was 4.6 per 100,000 men and women per year based on 2016-2020 cases, age-adjusted. Death rates from CLL are higher among older adults, or those 75 and older. The death rate was 1.1 per 100,000 men and women per year based on 2016-2020 deaths, age-adjusted. A common question that patients with CLL ask during their first clinic visit is: "How long will it be before I would need treatment?" Although this might seem like a simple question, the answer is not straight forward. CLL is a heterogenous disease, with a variable clinical course. Some patients may present with an aggressive disease requiring early initiation of treatment, while others have an indolent course and some, having so called smoldering CLL, may never need treatment. The variability in disease course can make predicting disease prognosis a complicated process. This brings forth the importance of establishing prognostic models that can predict disease course, time to treatment, and survival outcomes in such a heterogenous disease. The Rai and Binet staging systems were developed in the late 1970s to early 1980s. They separated patients into different stages based on clinical characteristics and laboratory findings. These simple staging systems are still in use; however, several prognostic markers need to be added for an individualized assessment and, with the recent development of genomic techniques leading to better understanding of CLL at the molecular level, newer prognostic markers have emerged.

Immune Evasion Through Human Leukocyte Antigen Implications and Its Impact on Targeted Therapy

The malfunctioning of human leukocyte antigen (HLA) class I antigens has a substantial negative impact on the effectiveness of leukemia treatment, particularly in the development of immunotherapies that rely on T-cell activation. HLA-G, a molecule that suppresses the immune response, plays a role in repressing the activation and proliferation of T cells, natural killer cells, and antigen-presenting cells. The expression of HLA-G is associated with various pathological conditions. Tumor cells exploit the immune evasion capabilities of HLA, allowing them to evade detection and elimination by the immune system. Understanding and modifying the HLA molecules is crucial for the advancement of innovative immunotherapies targeting chronic lymphocytic leukemia. Numerous mechanisms have been investigated to elucidate how HLA facilitates tumor evasion in patients with chronic lymphocytic leukemia and other malignancies. These mechanisms include inhibiting immune cell cytolysis, altering cytokine production levels, promoting immune cell programmed cell death, and impairing chemotaxis. This review provides a comprehensive overview of immune evasion mediated by HLA and its implications for targeted therapy.

Low Alanine-Aminotransferase Blood Activity Is Associated with Increased Mortality in Chronic Lymphocytic Leukemia Patients: A Retrospective Cohort Study of 716 Patients

BACKGROUND

Chronic lymphocytic leukemia (CLL) is one of the most common hematologic malignancies, especially among elderlies. Several prognostic scores are available that utilize the characteristics of patients' blood counts and cytogenetic anomalies-all are features of the disease rather than of the patient. Addressing the route of personalized rather than precise medicine, we refer to the assessment of patients' status of sarcopenia and frailty. Low alanine aminotransferase (ALT) was already shown to function as a surrogate marker for sarcopenia and frailty. We decided to find a possible correlation between low ALT values and poor prognosis of CLL patients.

PATIENTS AND METHODS

This is a retrospective cohort study of CLL patients treated in a large, tertiary medical center, as outpatients or inpatients. Their frailty status was evaluated in a retrospective manner. We defined patients with ALT below 12 IU/L as frail and divided our cohort into two groups including a low ALT level group (ALT < 12) and a normal ALT level group (ALT ≥ 12).

RESULTS

Overall, our final analysis included 716 CLL patients, of which 161 (22.5%) had ALT levels lower than 12 IU/L. There was no significant difference in patients' age between the two groups. Patients with the low ALT had a lower hemoglobin concentration (median 10.8 g/dL [IQR = 2.7] vs. 12.2 [IQR = 3.1]; p < 0.001) and a higher proportion of patients were classified as Binet C score [48.4% vs. 31.1%]; p < 0.001). Frail CLL patients' survival was significantly shorter when compared to non-frail patients, in both the univariate [HR = 1.6 [95% confidence interval, CI 1.23, 2.0]; p < 0.01] and multivariate analyses [HR = 1.3 [95% CI 1.0, 1.7]; p = 0.03].

CONCLUSIONS

Sarcopenia and frailty assessment, based on blood ALT measurements, could potentially point out differences in CLL patients' prognoses. Such assessment could serve the purpose of treatment personalization of CLL patients.

Empirical Study on Exploring the Role of CD180 and MD-1 Prognostic Indicators for the Chronic Lymphocytic Leukaemia (CLL) Disease

&lt;b&gt;Background and Objective:&lt;/b&gt; Chronic Lymphocytic Leukaemia (CLL) is a frequent type of leukaemia disease. This study was focused on investigating the role of prognostic indicators, such as CD180 and MD-1 for Chronic Lymphocytic Leukaemia (CLL) pathogenesis because they involve cell signalling and proliferation. &lt;b&gt;Materials and Methods:&lt;/b&gt; A total of 12 normal controls and 52 patients were taken to determine the expressions of CD180 and MD-1 with different variations in comparison with the IgVH (Immunoglobulin Heavy Chain variable region gene) mutational status, FISH (fluorescence &lt;i&gt;in situ&lt;/i&gt; hybridization) and Rai staging. &lt;b&gt;Results:&lt;/b&gt; The quantitative data findings were evident that CD180 and MD-1 expressions showed insignificant differences among CLL patients at the protein level based on SPSS results. On the contrary, they resulted in significant differences for subgroups of established biomarkers like Rai staging (stages 0, I, II and III), FISH (13q and non-13q deletions) and IgVH (mutated and unmutated). &lt;b&gt;Conclusion:&lt;/b&gt; The CD180 and MD-1 have been used as prognostic indicators to evaluate the outcomes relevant to the cell cycle and survival rate of CLL cells.

Assessment of Impact of Human Leukocyte Antigen-Type and Cytokine-Type Responses on Outcomes after Targeted Therapy Currently Used to Treat Chronic Lymphocytic Leukemia

Tumor growth and metastasis are reliant on intricate interactions between the host immune system and various counter-regulatory immune escape mechanisms employed by the tumor. Tumors can resist immune surveillance by modifying the expression of human leukocyte antigen (HLA) molecules, which results in the impaired presentation of tumor-associated antigens, subsequently evading detection and destruction by the immune system. The management of chronic lymphocytic leukemia (CLL) is based on symptom severity and includes various types of targeted therapies, including rituximab, obinutuzumab, ibrutinib, acalabrutinib, zanubrutinib, idelalisib, and venetoclax. These therapies rely on the recognition of specific peptides presented by HLAs on the surface of tumor cells by T cells, leading to an immune response. HLA class I molecules are found in most human cell types and interact with T-cell receptors (TCRs) to activate T cells, which play a vital role in inducing adaptive immune responses. However, tumor cells may evade T-cell attack by downregulating HLA expression, limiting the efficacy of HLA-dependent immunotherapy. The prognosis of CLL largely depends on the presence or absence of genetic abnormalities, such as del(17p), TP53 point mutations, and IGHV somatic hypermutation status. These oral targeted therapies alone or in combination with anti-CD20 antibodies have replaced chemoimmunotherapy as the primary treatment for CLL. In this review, we summarize the current clinical evidence on the impact of HLA- and cytokine-type responses on outcomes after targeted therapies currently used to treat CLL.

Genome-wide DNA methylation profiling in chronic lymphocytic leukaemia

Background: DNA methylation aberrations are widespread among the malignant B lymphocytes of patients with chronic lymphocytic leukaemia (CLL), suggesting that DNA methylation might contribute to the pathogenesis of CLL. Aim: We aimed to explore the differentially methylated positions (DMPs) associated with CLL and screen the differentially methylated and expressed genes (DMEGs) by combining public databases. We aimed to observe the direction of each DMEG in CLL based on the DMPs in the promoter and the body region respectively to narrow down DMEGs. We also aimed to explore the methylation heterogeneity of CLL subgroups and the effect of B cells maturation on CLL. Methods: In this population-based case control study, we reported a genome-wide DNA methylation association study using the Infinium HumanMethylation450 BeadChip, profiling the DNA methylation of CD19⁺ B Cells from 48 CLL cases and 28 healthy controls. By integrating methylation data and expression data from public databases, gene sets were jointly screened, and then the relationship between methylation sites in promoter and body region and expression of each gene was explored. In addition, support vector machine (SVM) classification algorithm was used to identify subgroups of CLL cases based on methylation pattern, and the effect of B-cell differentiation related methylation sites on CLL-related sites was observed. Results: We identified 34,797 DMPs related to CLL across the genome, most of which were hypomethylated; the majority were located in gene body regions. By combining these DMPs with published DNA methylation and RNA sequencing data, we detected 26,244 replicated DMPs associated with 1,130 genes whose expression were significantly different in CLL cases. Among these DMEGs, nine low expressed DMEGs were selected with hypermethylated in promoter and hypomethylated in body region, and 83 high expressed DMEGs were selected with both hypomethylated in promoter and body region. The 48 CLL cases were divided into 3 subgroups based on methylation site by SVM algorithm. Over 92% of CpGs associated with B cell subtypes were found in CLL-related DMPs. Conclusion: The DNA methylation pattern was altered across the genome in CLL patients. The methylation of ZAP70, FMOD, and ADAMTS17 was significantly different between CLL cases and controls. Further studies are warranted to confirm our findings and identify the underlying mechanisms through which these methylation markers are associated with CLL.

Successful treatment of persistent and severe SARS-CoV-2 infection in a high-risk chronic lymphocytic leukemia patient using Ronapreve™ antibodies

Patients with lymphoproliferative diseases are at an increased risk of an incomplete immune response following vaccination or SARS-CoV-2 infection and might develop persistent viral infection and severe COVID-19 disease. We present a case of successful treatment of persistent and mechanical-ventilation-requiring SARS-CoV-2 infection in a del17+ CLL patient using exogenous antibodies.

Impact of Low-Burden TP53 Mutations in the Management of CLL

In chronic lymphocytic leukemia (CLL), TP53 abnormalities are associated with reduced survival and resistance to chemoimmunotherapy (CIT). The recommended threshold to clinically report TP53 mutations is a matter of debate given that next-generation sequencing technologies can detect mutations with a limit of detection of approximately 1% with high confidence. However, the clinical impact of low-burden TP53 mutations with a variant allele frequency (VAF) of less than 10% remains unclear. Longitudinal analysis before and after fludarabine based on NGS sequencing demonstrated that low-burden TP53 mutations were present before the onset of treatment and expanded at relapse to become the predominant clone. Most studies evaluating the prognostic or predictive impact of low-burden TP53 mutations in untreated patients show that low-burden TP53 mutations have the same unfavorable prognostic impact as clonal defects. Moreover, studies designed to assess the predictive impact of low-burden TP53 mutations showed that TP53 mutations, irrespective of mutation burden, have an inferior impact on overall survival for CIT-treated patients. As low-burden and high-burden TP53 mutations have comparable clinical impacts, redefining the VAF threshold may have important implications for the clinical management of CLL.

Identifying patients with chronic lymphocytic leukemia without need of treatment: End of endless watch and wait?

INTRODUCTION

Early-stage chronic lymphocytic leukemia (CLL) challenges specialized management and follow-up.

METHODS

We developed and validated a prognostic index to identify newly diagnosed patients without need of treatment (CLL-WONT) by a training/validation approach using data on 4708 patients. Composite scores derived from weighted hazards by multivariable analysis defined CLL-WONT risk groups.

RESULTS

Age (>65 years: 1 point), Binet stage (B: 2 points), lactate dehydrogenase (LDH) (>205 U/L: 1 point), absolute lymphocyte count (15-30 × 10⁹ /L: 1 point; >30 × 10⁹ /L; 2 points), β2-microglobulin (>4 mg/L: 1 point), IGHV mutation status (unmutated: 1 point), and 11q or 17p deletion (1 point) were independently associated with shorter time to first treatment (TTFT). Low-risk patients demonstrated 5-year TTFT of 2% by internal validation, but 7-19% by external validation. Including all patients with complete scores, the 5-year TTFT was 10% for the 756 (39%) CLL-WONT low-risk patients, and the 704 (37%) patients who were both CLL-WONT and CLL-IPI low risk demonstrated even lower 5-year TTFT (8%).

CONCLUSION

We have adopted the CLL-WONT at an institution covering 1 800 000 individuals to allow patients with both low-risk CLL-WONT and CLL-IPI to be managed by primary healthcare providers, thereby prioritizing specialized hematology services for patients in dire need.

The CLL International Prognostic Index predicts outcomes in monoclonal B-cell lymphocytosis and Rai 0 CLL

The utility of the chronic lymphocytic leukemia-international prognostic index (CLL-IPI) in predicting outcomes of individuals with Rai 0 stage CLL and monoclonal B-cell lymphocytosis (MBL) is unclear. We identified 969 individuals (415 MBL and 554 Rai 0 CLL; median age, 64 years; 65% men) seen at Mayo Clinic between 1 January 2001 and 1 October 2018, and ascertained time to first therapy (TTFT) and overall survival (OS). After a median follow up of 7 years, the risk of disease progression needing therapy was 2.9%/y for MBL (median, not reached) and 5%/y for Rai 0 CLL (median, 10.4 years). Among patients with low, intermediate, and high/very high-risk CLL-IPI risk groups, the estimated 5-year risk of TTFT was 13.5%, 30%, and 58%, respectively, P< .0001 (c-statistic = 0.69); and the estimated 5-year OS was 96.3%, 91.5%, and 76%, respectively, P< .0001 (c-statistic = 0.65). In a multivariable analysis of absolute B-cell count with individual factors of the CLL-IPI, the absolute B-cell count was associated with shorter TTFT (hazard ratio [HR] for each 10 × 109/L increase: 1.31; P< .0001) and shorter OS (HR: 1.1; P = .02). The OS of the entire cohort was similar to that of the age- and sex-matched general population of Minnesota (P = .17), although Rai 0 CLL patients with high and very high-risk CLL-IPI score had significantly shorter OS (P= .01 and P= .0001, respectively). The results of this study demonstrate the ability of CLL-IPI to predict time from diagnosis to first treatment (an end point not affected by therapy) in a large cohort of patients whose only manifestation of disease is a circulating clonal lymphocyte population.

Natural history of monoclonal B-cell lymphocytosis among relatives in CLL families

Chronic lymphocytic lymphoma (CLL) has one of the highest familial risks among cancers. Monoclonal B-cell lymphocytosis (MBL), the precursor to CLL, has a higher prevalence (13%-18%) in families with 2 or more members with CLL compared with the general population (5%-12%). Although, the rate of progression to CLL for high-count MBLs (clonal B-cell count ≥500/µL) is ∼1% to 5%/y, no low-count MBLs have been reported to progress to date. We report the incidence and natural history of MBL in relatives from CLL families. In 310 CLL families, we screened 1045 relatives for MBL using highly sensitive flow cytometry and prospectively followed 449 of them. MBL incidence was directly age- and sex-adjusted to the 2010 US population. CLL cumulative incidence was estimated using Kaplan-Meier survival curves. At baseline, the prevalence of MBL was 22% (235/1045 relatives). After a median follow-up of 8.1 years among 449 relatives, 12 individuals progressed to CLL with a 5-year cumulative incidence of 1.8%. When considering just the 139 relatives with low-count MBL, the 5-year cumulative incidence increased to 5.7%. Finally, 264 had no MBL at baseline, of whom 60 individuals subsequently developed MBL (2 high-count and 58 low-count MBLs) with an age- and sex-adjusted incidence of 3.5% after a median of 6 years of follow-up. In a screening cohort of relatives from CLL families, we reported progression from normal-count to low-count MBL to high-count MBL to CLL, demonstrating that low-count MBL precedes progression to CLL. We estimated a 1.1% annual rate of progression from low-count MBL, which is in excess of that in the general population.

The prognostic value of serum levels of a proliferation-inducing ligand (APRIL) in treatment-naïve patients with chronic lymphocytic leukemia

Background/aim

A proliferation-inducing ligand (APRIL) has been investigated as a prognostic marker in chronic lymphocytic leukemia (CLL) patients. However, there is no cut-off level for serum APRIL (sAPRIL) levels that predict time to treatment in CLL patients.

Materials and methods

Between May and December 2012, 94 consecutive CLL patients and 25 healthy controls were assessed. sAPRIL levels were measured by ELISA. Demographic data and prognostic markers were obtained from the patients’ files. Treatment-naïve patients were followed up for 6.5 years for any treatment need.

Results

Patients were divided into 3 groups: Treatment-naïve (n = 47), chemotherapy receiving (n = 25), and those who had received chemotherapy previously (n = 22). There was no difference in median sAPRIL levels of patients who were receiving chemotherapy at the sampling time and the healthy controls, which indicates that sAPRIL levels might be influenced by treatment. For treatment-naïve patients, the best cut-off in predicting time to treatment was found at the sAPRIL level of 2.04 ng/mL, with 78% sensitivity and 63% specificity. Time to treatment was significantly earlier in the APRIL high group (n = 27) than in the APRIL low group (n = 20) (P = 0.010, log-rank test).

Conclusion

sAPRIL, a simple, promising blood test which can be measured by ELISA, will likely obtain a place in the wide range of prognostic markers in CLL. Prospective large-scale studies are required to validate and confirm the feasibility of the proposed cut-off level of 2.04 ng/mL as a predictor of time to treatment in treatment-naïve CLL patients.

Harrison C, Eswaran J, Soundararajan M. DAP Kinase-Related Apoptosis-Inducing Protein Kinase 2 (DRAK2) Is a Key Regulator and Molecular Marker in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the Western World and it is characterized by a marked degree of clinical heterogeneity. An impaired balance between pro- and anti-apoptotic stimuli determines chemorefractoriness and outcome. The low proliferation rate of CLL cells indicates that one of the primary mechanisms involved in disease development may be an apoptotic failure. Here, we study the clinical and functional significance of DRAK2, a novel stress response kinase that plays a critical role in apoptosis, T-cell biology, and B-cell activation in CLL. We have analyzed CLL patient samples and showed that low expression levels of DRAK2 were significantly associated with unfavorable outcome in our CLL cohort. DRAK2 expression levels showed a positive correlation with the expression of DAPK1, and TGFBR1. Consistent with clinical data, the downregulation of DRAK2 in MEC-1 CLL cells strongly increased cell viability and proliferation. Further, our transcriptome data from MEC-1 cells highlighted MAPK, NF-κB, and Akt and as critical signaling hubs upon DRAK2 knockdown. Taken together, our results indicate DRAK2 as a novel marker of CLL survival that plays key regulatory roles in CLL prognosis.

Exosome: From leukemia progression to a novel therapeutic approach in leukemia treatment

Exosomes, as small vesicles, are released by tumor cells and tumor microenvironment (cells and function as key intercellular mediators and effects on different processes including tumorigenesis, angiogenesis, drug resistance, and evasion from immune system. These functions are due to exosomes' biomolecules which make them as efficient markers in early diagnosis of the disease. Also, exosomes have been recently applied in vaccination. The potential role of exosomes in immune response toward leukemic cells makes them efficient immunotherapeutic agents treating leukemia. Furthermore, variations in exosomes contents make them beneficial to be used in treating different diseases. This review introduces the role of exosomes in the development of hematological malignancies and evaluates their functional role in the treatment of these malignancies.

Tumor mutational load predicts time to first treatment in chronic lymphocytic leukemia (CLL) and monoclonal B-cell lymphocytosis beyond the CLL international prognostic index

Next-generation sequencing identified about 60 genes recurrently mutated in chronic lymphocytic leukemia (CLL). We examined the additive prognostic value of the total number of recurrently mutated CLL genes (i.e., tumor mutational load [TML]) or the individually mutated genes beyond the CLL international prognostic index (CLL-IPI) in newly diagnosed CLL and high-count monoclonal B-cell lymphocytosis (HC MBL). We sequenced 59 genes among 557 individuals (112 HC MBL/445 CLL) in a multi-stage design, to estimate hazard ratios (HR) and 95% confidence intervals (CI) for time-to-first treatment (TTT), adjusted for CLL-IPI and sex. TML was associated with shorter TTT in the discovery and validation cohorts, with a combined estimate of continuous HR = 1.27 (CI:1.17-1.39, P = 2.6 × 10^-8 ; c-statistic = 0.76). When stratified by CLL-IPI, the association of TML with TTT was stronger and validated within low/intermediate risk (combined HR = 1.54, CI:1.37-1.72, P = 7.0 × 10^-14 ). Overall, 80% of low/intermediate CLL-IPI cases with two or more mutated genes progressed to require therapy within 5 years, compared to 24% among those without mutations. TML was also associated with shorter TTT in the HC MBL cohort (HR = 1.53, CI:1.12-2.07, P = .007; c-statistic = 0.71). TML is a strong prognostic factor for TTT independent of CLL-IPI, especially among low/intermediate CLL-IPI risk, and a better predictor than any single gene. Mutational screening at early stages may improve risk stratification and better predict TTT.

Promoter DNA Methylation Frequency and Clinicopathological Role of miR-129-2 Gene in Patients with Chronic Lymphocytic Leukemia

Objectives

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of apparently mature B-type lymphocytes in the lymphohematopoietic organs. Methylation in promoters of tumor suppressor genes is one of the mechanisms that causes blood malignancy. In this study, we evaluated the promoter DNA methylation status of miR-129-2 tumor suppressor gene and its association with clinical and laboratory parameters of patients with CLL.

Methods

We studied the promoter DNA methylation frequency of the miR-129-2 gene in 50 patients with CLL and 50 healthy controls using methylation-specific polymerase chain reaction methods. Statistical analysis was performed using SPSS-18 software, and a p-value < 0.050 was considered statistically significant.

Results

The frequency of promoter DNA methylation of the miR-129-2 gene was significantly higher in the CLL group compared with control group (38.0% vs. 0.0%, p < 0.001; χ² = 23.457). The promoter DNA methylation frequency of miR-129-2 gene was not significantly different between the two sexes (p = 0.236). A significant but weak correlation was seen between the methylated state of the miR-129-2 gene and organomegaly (p = 0.019, r = 0.330) as well as hemoglobin levels (p = 0.020, r = -0.233). However, binary logistic regression analysis indicated organomegaly as the only clinical biomarker with a statistically significant association with the hypermethylated miR-129-2 gene state (p = 0.046).

Conclusions

The high frequency of promoter DNA methylation of the miR-129-2 gene in the CLL group compared to the control group, as well as its significant association with organomegaly, suggests the importance of this epigenetic biomarker in the pathogenesis and prognosis of CLL disease.

Mitochondrial Genome-Derived circRNA mc-COX2 Functions as an Oncogene in Chronic Lymphocytic Leukemia

Circular RNAs (circRNAs), a novel family of non-coding RNAs, play crucial roles in cancer progression. While the existing research focuses on nuclear genome-derived (nu)-circRNAs, the biological and clinical characteristics of mitochondrial genome-derived (mt)-circRNAs remain largely unknown, especially in chronic lymphocytic leukemia (CLL). In this study, we attempted to identify the novel characteristics of mc-COX2 (mitochondrial genome-derived circRNAs [mc]), one of the mt-circRNAs that can be involved in CLL progression. mt-circRNAs were found to be highly expressed in the plasma exosomes of CLL patients. The endogenous reduction of mc-COX2 can affect mitochondrial functions, suppress cell proliferation, and induce cell apoptosis. The upregulation of mc-COX2 was positively associated with leukemogenesis and worsening survival of CLL patients. Notably, functional analysis revealed that mc-COX2, as differing from conventional nu-circRNAs, was less stable and may function through novel mechanisms other than acting as the competing endogenous RNA. We also screened and tested several chemical compounds and small-molecule inhibitors that can decrease the generation of mc-COX2. It was found that the silencing of mc-COX2 in CLL cells strengthened the anti-tumor effects of drugs used in coordination. Our findings prove that mc-COX2, a critical mt-circRNA highly expressed in plasma, derived from CLL cells and delivered by exosomes, is associated with the progression and prognosis of CLL.

Effects of eEF1A1 targeting by aptamer/siRNA in chronic lymphocytic leukaemia cells

BACKGROUND

The effectiveness of therapies for chronic lymphocytic leukemia (CLL), the most common leukemia in Western countries adults, can be improved via a deeper understanding of its molecular abnormalities. Whereas the isoforms of the eukaryotic elongation factor 1A (eEF1A1 and eEF1A2) are implicated in different tumors, no information are available in CLL.

METHODS

eEF1A1/eEF1A2 amounts were quantitated in the lymphocytes of 46 CLL patients vs normal control (real time PCR, western blotting). eEF1A1 role in CLL was investigated in a cellular (MEC-1) and animal model of CLL via its targeting by an aptamer (GT75) or a siRNA (siA1) delivered by electroporation (in vitro) or lipofection (in vivo).

RESULTS

eEF1A1/eEF1A2 were elevated in CLL lymphocytes vs control. eEF1A1 but not eEF1A2 levels were higher in patients which died during the study compared to those surviving. eEF1A1 targeting (GT75/siA1) resulted in MEC-1 viability reduction/autophagy stimulation and in vivo tumor growth down-regulation.

CONCLUSIONS

The increase of eEF1A1 in dead vs surviving patients may confer to eEF1A1 the role of a prognostic marker for CLL and possibly of a therapeutic target, given its involvement in MEC-1 survival. Specific aptamer/siRNA released by optimized delivery systems may allow the development of novel therapeutic options.

Machine learning can identify newly diagnosed patients with CLL at high risk of infection

Infections have become the major cause of morbidity and mortality among patients with chronic lymphocytic leukemia (CLL) due to immune dysfunction and cytotoxic CLL treatment. Yet, predictive models for infection are missing. In this work, we develop the CLL Treatment-Infection Model (CLL-TIM) that identifies patients at risk of infection or CLL treatment within 2 years of diagnosis as validated on both internal and external cohorts. CLL-TIM is an ensemble algorithm composed of 28 machine learning algorithms based on data from 4,149 patients with CLL. The model is capable of dealing with heterogeneous data, including the high rates of missing data to be expected in the real-world setting, with a precision of 72% and a recall of 75%. To address concerns regarding the use of complex machine learning algorithms in the clinic, for each patient with CLL, CLL-TIM provides explainable predictions through uncertainty estimates and personalized risk factors.

Chronic lymphocytic leukemia is an indolent disease, and many patients succumb to infection rather than the direct effects of the disease. Here, the authors use medical records and machine learning to predict the patients that may be at risk of infection, which may enable a change in the course of their treatment.

The Number of Signaling Pathways Altered by Driver Mutations in Chronic Lymphocytic Leukemia Impacts Disease Outcome

PURPOSE

Investigation of signaling pathways altered by recurrent gene mutations and their clinical impact in a consecutive cohort of patients with newly diagnosed chronic lymphocytic leukemia (CLL). The heterogeneous clinical course and genetic complexity of CLL warrant improved molecular prognostication. However, the prognostic value of recurrent mutations at the time of diagnosis remains unclear.

EXPERIMENTAL DESIGN

We sequenced samples from 314 consecutive, newly diagnosed patients with CLL to investigate the clinical impact of 56 recurrently mutated genes assessed by next-generation sequencing.

RESULTS

Mutations were identified in 70% of patients with enrichment among IGHV unmutated cases. With 6.5 years of follow-up, 15 mutated genes investigated at the time of diagnosis demonstrated significant impact on time to first treatment (TTFT). Carrying driver mutations was associated with shorter TTFT and poor overall survival. For outcome from CLL diagnosis, the number of signaling pathways altered by driver mutations stratified patients better than the number of driver mutations. Moreover, we demonstrated gradual impact on TTFT with increasing number of altered pathways independent of CLL-IPI risk. Thus, a 25-gene, pathway-based biomarker assessing recurrent mutations refines prognostication in CLL, in particular for CLL-IPI low- and intermediate-risk patients. External validation emphasized that a broad gene panel including low burden mutations was key for the biomarker based on altered pathways.

CONCLUSIONS

We propose to include the number of pathways altered by driver mutations as a biomarker together with CLL-IPI in prospective studies of CLL from time of diagnosis for incorporation into clinical care and personalized follow-up and treatment.

Role of long non-coding RNAs in disease progression of early stage unmutated chronic lymphocytic leukemia

Predicting disease progression in chronic lymphocytic leukemia (CLL) remains challenging particularly in patients with Rai Stage 0/I disease that have an unmutated immunoglobulin heavy chain variable region (UM IGHV). Even though patients with UM IGHV have a poor prognosis and generally require earlier treatment, not all UM IGHV patients experience more rapid disease progression with some remaining treatment free for many years. This observation suggests biologic characteristics other than known prognostic factors influence disease progression. Alterations in long non-coding RNA (lncRNA) expression levels have been implicated in diagnosis and prognosis of various cancers, however, their role in disease progression of early Rai stage UM CLL is unknown. Here we use microarray analysis to compare lncRNA and mRNA profiles of Rai 0/I UM IGHV patients who progressed in <2 years relative to patients who had not progressed for >5 years. Over 1,300 lncRNAs and 940 mRNAs were differentially expressed (fold change ≥ 2.0; p-value ≤ 0.05). Of interest, the differentially expressed lncRNAs T204050, NR_002947, and uc.436+, have known associated genes that have been linked to CLL. Thus, our study reveals differentially expressed lncRNAs in progressive early stage CLL requiring therapy versus indolent early Rai stage UM CLL. These lncRNAs have the potential to impact relevant biological processes and pathways that influence clinical outcome in CLL.

Prognostic Factors in the Era of Targeted Therapies in CLL

PURPOSE OF REVIEW

Chronic lymphocytic leukemia is heterogeneous disease characterized by a variable clinical course that is greatly influenced by various patient and disease characteristics. Over the last two decades, advent of new diagnostic methodologies has led to the identification of several factors of prognostic and predictive relevance. Furthermore, recent advances in next-generation sequencing techniques has identified recurrent novel mutations in NOTCH1, SF3B1, BIRC3, and ATM genes whose role as prognostic and predictive markers is currently being investigated. These biologic markers carry new prognostic information and their incorporation into prognostic scoring systems will likely lead to refined multi-parameter risk models.

RECENT FINDINGS

While the prognostic impact of many of the most commonly used markers on clinical outcomes in patients treated with chemo-immunotherapy is well documented, it is important to review their predictive and prognostic role in the era of novel targeted therapies. This article will discuss the currently available information on the clinical relevance of prognostic markers in patients treated with novel targeted therapies.

Deep targeted sequencing of TP53 in chronic lymphocytic leukemia: clinical impact at diagnosis and at time of treatment

In chronic lymphocytic leukemia, TP53 mutations and deletion of chromosome 17p are well-characterized biomarkers associated with poor progression-free and overall survival following chemoimmunotherapy. Patients harboring low burden TP53 mutations with variant allele frequencies of 0.3-15% have been shown to have similar dismal outcome as those with high burden mutations. We here describe a highly sensitive deep targeted next-generation sequencing assay allowing for the detection of TP53 mutations as low as 0.2% variant allele frequency. Within a consecutive, single center cohort of 290 newly diagnosed patients with chronic lymphocytic leukemia, deletion of chromosome 17p was the only TP53 aberration significantly associated with shorter overall survival and treatment-free survival. We were unable to demonstrate any impact of TP53 mutations, whether high burden (variant allele frequency >10%) or low burden (variant allele frequency ≤10%), in the absence of deletion of chromosome 17p. In addition, the impact of high burden TP53 aberration (deletion of chromosome 17p and/or TP53 mutation with variant allele frequency >10%) was only evident for patients with IGHV unmutated status; no impact of TP53 aberrations on outcome was seen for patients with IGHV mutated status. In 61 patients at time of treatment, the prognostic impact of TP53 mutations over 1% variant allele frequency could be confirmed. This study furthers the identification of a clinical significant limit of detection for robust TP53 mutation analysis in chronic lymphocytic leukemia. Multicenter studies are needed for validation of ultra-sensitive TP53 mutation assays in order to define and implement a technical as well as a clinical lower limit of detection.

On the architecture of translational research designed to control chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) has been 1 of the most dynamic fields of clinical research over the last 2 decades. Important advances in understanding the biology of CLL have led to the development of new prognostic and diagnostic tools. Concurrently, several recently approved new agents hold the potential to fundamentally change the management of this leukemia and have started to improve clinical outcomes for patients. This conceptual review summarizes the major recent insights regarding the biology of CLL, the technological advances that have allowed refinement of the prognostication of the clinical course, and the new therapeutic strategies that are currently under investigation to further ameliorate the outcome for patients with CLL.

SENP2 exerts an anti‑tumor effect on chronic lymphocytic leukemia cells through the inhibition of the Notch and NF‑κB signaling pathways

Chronic lymphocytic leukemia (CLL) is one of the most often diagnosed hematological malignant tumors in the Western world and a type of inert B-cell lymphoma that commonly attacks the elderly. Small ubiquitin related modifier (SUMO)-specific protease 2 (SENP2) can act as a suppressor in various types of cancer by regulating the stability of β-catenin to affect the Notch signaling pathway; however, it has a low expression level in CLL cells. In this study, we firstly used western blot analysis and RT-qPCR to detect the protein and mRNA expression levels of SENP2 in the peripheral blood of patients with CLL and healthy volunteers. Secondly, we overexpressed or knocked down the expression of SENP2 in CLL cells and then determined the cell invasive and chemotactic ability in a Transwell assay and chemotaxis assay. We examined the sensitivity of the cells to cytarabine and dexamethasone via a CCK-8 assay and determined the cell apoptotic condition and the expression of the Notch signaling pathway using flow cytometry and western blot analysis. The results demonstrated that the patients with CLL had relatively low expression levels of SENP2. The overexpression of SENP2 in the CLL cells decreased their invasive and proliferative ability, as well as their chemotactic response and enhanced their sensitivity to cytarabine and dexamethasone, while it promoted cell apoptosis. The silencing of SENP2 in the CLL cells generally produced the opposite results. We thus hypothesized that the overexpression of SENP2 downregulated β-catenin expression, thus inhibiting the Notch signaling pathway in CLL cells. Moreover, the nuclear factor (NF)-κB signaling pathway was also regulated by the overexpression of SENP2. On the whole, the findings of this study indicate tha SENP2 can act as a tumor suppressor in CLL cells, and may thus prove to be a novel target for CLL treatment in clinical practice.

Chronic lymphocytic leukemia treatment algorithm 2018

The treatment landscape for patients with chronic lymphocytic leukemia (CLL) has changed considerably with the introduction of very effective oral targeted therapies (such as ibrutinib, idelalisib, and venetoclax), and next-generation anti-CD20 monoclonal antibodies (such as obinutuzumab). These agents lead to improved outcomes in CLL, even among patients with high-risk features, such as del17p13 or TP53 mutation and unmutated immunoglobulin heavy chain (IGHV) genes. Each of these treatments is associated with a unique toxicity profile; in the absence of randomized data, the choice of one type of treatment over another depends on the co-morbidities of the patient. Chemoimmunotherapy still plays an important role in the management of previously untreated CLL patients, particularly among young fit patients who have standard risk FISH profile and mutated IGHV genes. Richter's transformation of CLL remains a difficult complication to treat, although therapy with programmed death 1 inhibitors such as pembrolizumab and nivolumab has shown impressive responses in a subset of patients. Our ability to risk stratify CLL patients continues to evolve; the CLL-International Prognostic Index (CLL-IPI) is the best validated tool in predicting time to first therapy among previously untreated patients. This review summarizes the current approach to risk stratification and management of CLL patients.

Oxidative stress in chronic lymphocytic leukemia: still a matter of debate

There is a large body of evidence showing a strong correlation between carcinogenesis of several types of human tumors, including chronic lymphocytic leukemia (CLL), and oxidative stress (OS). The mechanisms by which OS may promote cancer pathogenesis have not been completely deciphered yet and, in CLL, as in other neoplasms, whether OS is a primary cause or simply a downstream effect of the disease is still an open question. It has been demonstrated that, in CLL, OS concomitantly results from increased reactive oxygen species (ROS) production, mainly ascribable to CLL cells mitochondrial activity, and impaired antioxidant defenses. Interestingly, OS evaluation in CLL patients, at diagnosis, seems to have a prognostic significance, thus getting new insights in the biological comprehension of the disease with potential therapeutic implications.

Inhibition of maternal embryonic leucine zipper kinase with OTSSP167 displays potent anti-leukemic effects in chronic lymphocytic leukemia

TP53 pathway defects contributed to therapy resistance and adverse clinical outcome in chronic lymphocytic leukemia (CLL), which represents an unmet clinical need with few therapeutic options. Maternal embryonic leucine zipper kinase (MELK) is a novel oncogene, which plays crucial roles in mitotic progression and stem cell maintenance. OTSSP167, an orally administrated inhibitor targeting MELK, is currently in a phase I/II clinical trial in patients with advanced breast cancer and acute myeloid leukemia. Yet, no investigation has been elucidated to date regarding the oncogenic role of MELK and effects of OTSSP167 in chronic lymphocytic leukemia (CLL). Previous studies confirmed MELK inhibition abrogated cancer cell survival via p53 signaling pathway. Thus, we aimed to determine the biological function of MELK and therapeutic potential of OTSSP167 in CLL. Herein, MELK over-expression was observed in CLL cells, and correlated with higher WBC count, advanced stage, elevated LDH, increased β2-MG level, unmutated IGHV, positive ZAP-70, deletion of 17p13 and inferior prognosis of CLL patients. In accordance with functional enrichment analyses in gene expression profiling, CLL cells with depletion or inhibition of MELK exhibited impaired cell proliferation, enhanced fast-onset apoptosis, induced G2/M arrest, attenuated cell chemotaxis and promoted sensitivity to fludarabine and ibrutinib. However, gain-of-function assay showed increased cell proliferation and cell chemotaxis. In addition, OTSSP167 treatment reduced phosphorylation of AKT and ERK1/2. It decreased FoxM1 phosphorylation, expression of FoxM1, cyclin B1 and CDK1, while up-regulating p53 and p21 expression. Taken together, MELK served as a candidate of therapeutic target in CLL. OTSSP167 exhibits potent anti-tumor activities in CLL cells, highlighting a novel molecule-based strategy for leukemic interventions.

Chronic Lymphocytic Leukemia: Diagnosis and Treatment

The complexity of the treatment of patients with chronic lymphocytic leukemia has increased substantially over the past several years as a consequence of the advent of novel biological agents such as ibrutinib, idelalisib, and venetoclax, as well as increasingly potent anti-CD20 monoclonal antibodies. In addition, the identification of molecular predictive markers and the introduction of more sensitive and sophisticated techniques to assess minimal residual disease have allowed optimization of the use of chemoimmunotherapy and targeted therapies and may become standard of care in the future. This review summarizes the diagnosis, prognostication, and treatment of patients with chronic lymphocytic leukemia with emphasis on new prognostic and predictive factors and novel treatment strategies.

ZAP-70 in chronic lymphocytic leukemia: A meta-analysis

BACKGROUND

Recent studies have reported that zeta-chain-associated protein kinase 70 (ZAP-70) expression plays a prognostic role in chronic lymphocytic leukemia (CLL). However, these results remain controversial. Thus, we performed a meta-analysis to clarify the prognostic value of ZAP-70 expression in CLL.

MATERIALS AND METHODS

Relevant studies were searched in PubMed, Embase, Cochrane library, and Web of Science up to January 2018. Clinicopathological features and prognostic data were extracted from the studies. We pooled estimates and 95% confidence intervals (CIs) and estimated the heterogeneity of studies using Mantel-Haenszel or DerSimonian and Laird method.

RESULTS

Twelve studies that included 1956 patients with CLL were eligible for inclusion. The pooled results revealed that increased ZAP-70 expression was significantly associated with poor overall survival (hazard ratio [HR] = 2.48, 95% CI: 1.72-3.59, P = 0.019, I² = 53.0%) and event-free survival (HR = 4.17, 95% CI: 2.17-8.01, P = 0.014, I² = 68.2%) in a random-effects model with significant heterogeneity. Clinicopathological analysis demonstrated that ZAP-70 expression was significantly associated with unmutated immunoglobulin heavy-chain genes, CD38 expression, serum β-2 microglobulin, and lymphocyte doubling time.

CONCLUSIONS

Our findings indicated that ZAP-70 was a strong prognostic biomarker for patients with CLL.

Targeting the Adenosinergic Axis in Chronic Lymphocytic Leukemia: A Way to Disrupt the Tumor Niche?

Targeting adenosine triphosphate (ATP) metabolism and adenosinergic signaling in cancer is gaining momentum, as increasing evidence is showing their relevance in tumor immunology and biology. Chronic lymphocytic leukemia (CLL) results from the expansion of a population of mature B cells that progressively occupies the bone marrow (BM), the blood, and peripheral lymphoid organs. Notwithstanding significant progress in the treatment of these patients, the cure remains an unmet clinical need, suggesting that novel drugs or drug combinations are needed. A unique feature of CLL is its reliance on micro-environmental signals for proliferation and cell survival. We and others have shown that the lymphoid niche, an area of intense interactions between leukemic and bystander non-tumor cells, is a typically hypoxic environment. Here adenosine is generated by leukemic cells, as well as by cells of myeloid origin, acting through autocrine and paracrine mechanisms, ultimately affecting tumor growth, limiting drug responses, and skewing the immune cells towards a tolerant phenotype. Hence, understanding the mechanisms through which this complex network of enzymes, receptors, and metabolites functions in CLL, will pave the way to the use of pharmacological agents targeting the system, which, in combination with drugs targeting leukemic cells, may get us one step closer to curing these patients.

iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL

The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.

Subtype assignment of CLL based on B-cell subset associated gene signatures from normal bone marrow - A proof of concept study

Diagnostic and prognostic evaluation of chronic lymphocytic leukemia (CLL) involves blood cell counts, immunophenotyping, IgVH mutation status, and cytogenetic analyses. We generated B-cell associated gene-signatures (BAGS) based on six naturally occurring B-cell subsets within normal bone marrow. Our hypothesis is that by segregating CLL according to BAGS, we can identify subtypes with prognostic implications in support of pathogenetic value of BAGS. Microarray-based gene-expression samples from eight independent CLL cohorts (1,024 untreated patients) were BAGS-stratified into pre-BI, pre-BII, immature, naïve, memory, or plasma cell subtypes; the majority falling within the memory (24.5-45.8%) or naïve (14.5-32.3%) categories. For a subset of CLL patients (n = 296), time to treatment (TTT) was shorter amongst early differentiation subtypes (pre-BI/pre-BII/immature) compared to late subtypes (memory/plasma cell, HR: 0.53 [0.35-0.78]). Particularly, pre-BII subtype patients had the shortest TTT among all subtypes. Correlates derived for BAGS subtype and IgVH mutation (n = 405) revealed an elevated mutation frequency in late vs. early subtypes (71% vs. 45%, P < .001). Predictions for BAGS subtype resistance towards rituximab and cyclophosphamide varied for rituximab, whereas all subtypes were sensitive to cyclophosphamide. This study supports our hypothesis that BAGS-subtyping may be of tangible prognostic and pathogenetic value for CLL patients.

Guidelines for Diagnosis and Treatment of Chronic Lymphocytic Leukemia. Krohem B-Cll 2017

Recent developments in the diagnosis and treatment of chronic lymphocytic leukemia (B-CLL) have led to change of approach in clinical practice. New treatments have been approved based on the results of randomized multicenter trials for first line and for salvage therapy, and the results of numerous ongoing clinical trials are permanently providing new answers and further refining of therapeutic strategies. This is paralleled by substantial increase in understanding the disease genetics due to major advances in the next generation sequencing (NGS) technology. We define current position of the Croatian Cooperative Group for Hematologic Disease on diagnosis and treatment of CLL in the transition from chemo-immunotherapy paradigm into a new one that is based on new diagnostic stratification and unprecedented therapeutic results of B-cell receptor inhibitors (BRI) and Bcl-2 antagonists. This is a rapidly evolving field as a great number of ongoing clinical trials con-stantly accumulate and provide new knowledge. We believe that novel therapy research including genomic diagnosis is likely to offer new options that will eventually lead to time limited therapies without chemotherapy and more effective clinical care for B-CLL based on individualized precision medicine.

Cumulative experience and long term follow-up of pentostatin-based chemoimmunotherapy trials for patients with chronic lymphocytic leukemia

BACKGROUND

7 regimens of pentostatin based chemoimmunotherapy (CIT) for progressive previously untreated CLL primarily with long term follow-up to update both efficacy and toxicity.

RESEARCH DESIGN AND METHODS

Prognostic markers including assessment of IGVH and FISH status were done on all. Response rates and 95% binomial confidence intervals were calculated for each regimen and in the combined cohort. Overall survival and treatment-free survival were evaluated using Kaplan-Meier methods.

RESULTS

The initial CIT trial was pentostatin (2 mgs/m2), cyclophosphamide (600 mg/m2) and rituximab (PCR) but subsequent P based CIT trials with modifications in subsequent trials. The cohort (n = 288) included 52% with unmutated IGVH status and del17p (4.5%) and del11q (14.9%). Toxicity profiles were primarily hematologic and no patient has developed MDS or AML after a median follow-up of 6.4 years. The overall response rate across all trials was found to be over 90% with a 41% complete response rate. We validated that the CLL IPI model segregates progressive CLL patients into 4 risk groups associated with OS and TFS.

CONCLUSIONS

The high overall and complete response levels in favorable genetic risk CLL along with favorable toxicity profiles provide rationale for consideration of a PC based strategy for previously untreated progressive CLL.

Low catalase expression confers redox hypersensitivity and identifies an indolent clinical behavior in CLL

B-cell receptor (BCR) signaling is a key determinant of variable clinical behavior and a target for therapeutic interventions in chronic lymphocytic leukemia (CLL). Endogenously produced H₂O₂ is thought to fine-tune the BCR signaling by reversibly inhibiting phosphatases. However, little is known about how CLL cells sense and respond to such redox cues and what effect they have on CLL. We characterized the response of BCR signaling proteins to exogenous H₂O₂ in cells from patients with CLL, using phosphospecific flow cytometry. Exogenous H₂O₂ in the absence of BCR engagement induced a signaling response of BCR proteins that was higher in CLL with favorable prognostic parameters and an indolent clinical course. We identified low catalase expression as a possible mechanism accounting for redox signaling hypersensitivity. Decreased catalase could cause an escalated accumulation of exogenous H₂O₂ in leukemic cells with a consequent greater inhibition of phosphatases and an increase of redox signaling sensitivity. Moreover, lower levels of catalase were significantly associated with a slower progression of the disease. In leukemic cells characterized by redox hypersensitivity, we also documented an elevated accumulation of ROS and an increased mitochondrial amount. Taken together, our data identified redox sensitivity and metabolic profiles that are linked to differential clinical behavior in CLL. This study advances our understanding of the redox and signaling heterogeneity of CLL and provides the rationale for the development of therapies targeting redox pathways in CLL.

Highly similar genomic landscapes in monoclonal B-cell lymphocytosis and ultra-stable chronic lymphocytic leukemia with low frequency of driver mutations

Despite the recent discovery of recurrent driver mutations in chronic lymphocytic leukemia, the genetic factors involved in disease onset remain largely unknown. To address this issue, we performed whole-genome sequencing in 11 individuals with monoclonal B- cell lymphocytosis, both of the low-count and high-count subtypes, and 5 patients with ultra-stable chronic lymphocytic leukemia (>10 years without progression from initial diagnosis). All three entities were indistinguishable at the genomic level exhibiting low genomic complexity and similar types of somatic mutations. Exonic mutations were not frequently identified in putative chronic lymphocytic leukemia driver genes in all settings, including low-count monoclonal B-cell lymphocytosis. To corroborate these findings, we also performed deep sequencing in 11 known frequently mutated genes in an extended cohort of 28 monoclonal B-cell lymphocytosis/chronic lymphocytic leukemia cases. Interestingly, shared mutations were detected between clonal B cells and paired polymorphonuclear cells, strengthening the notion that at least a fraction of somatic mutations may occur before disease onset, likely at the hematopoietic stem cell level. Finally, we identified previously unreported non-coding variants targeting pathways relevant to B-cell and chronic lymphocytic leukemia development, likely associated with the acquisition of the characteristic neoplastic phenotype typical of both monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia.

Single cell profiling of phospho-protein levels in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) has a high incidence and a steeply growing prevalence in the Western world. The heterogeneity of the disease necessitates individual mapping of biology and predicted drug response in each patient as basis for administration of tailored treatments. Cell signaling aberrations may serve as biological indicators for suitable therapy. By applying phospho-specific flow cytometry, we mapped basal and induced phosphorylation levels of 20 phospho-epitopes on proteins relevant to B-cell signaling in B cells from 22 CLL patients and 25 normal controls. The signaling response of the cytostatic drugs fludarabine, doxorubicin and vincristine was also investigated. CLL cells exerted similar or lower basal phosphorylation levels compared to normal B cells, with the exception of STAT3 (pY705) which was increased. Interestingly, STAT3 inhibitors normalized the STAT3 (pY705) level and reduced cell viability. Vincristine treatment significantly modulated phosphorylation levels in CLL cells, while no effect was observed in controls or after fludarabine or doxorubicin treatment. After BCR stimulation, CLL cells showed a tendency towards impaired phosphorylation levels, significant for several of the analyzed proteins. However, the level of Akt (pS473) was more potently induced in IgHV unmutated CLL (UM-CLL) patient samples and was significantly higher than in M-CLL samples. Importantly, the PI3Kδ inhibitor idelalisib potently reversed the effect of anti-IgM on Akt (pS473). Thus, signaling aberrations could be identified by phosphoflow cytometry and aberrant signaling could be normalized by small molecule drugs. This approach can identify relevant drug targets as well as drug effects in the individual patient.

Optimizing frontline therapy of CLL based on clinical and biological factors

The heterogeneity of the clinical course of chronic lymphocytic leukemia (CLL) ranges from an indolent course, where patients do not require therapy for many years, to a very aggressive disease, where treatment is required soon after diagnosis and relapses may occur early. The improved tools for prognostication allow predicting the outcome of patients with increasing reliability. Some markers also allow selecting more specific therapies with improved activity in the presence of certain genetic or clinical features of CLL. Of these markers, TP53 dysfunction, age, the presence of comorbidities and the immunoglobulin heavy-chain variable region gene mutational status, or serum markers such as β2-microglobulin have shown independent prognostic value in multiple prospective trials. During the last 10 years, multiple novel agents have become available. The advent of oral kinase inhibitors or Bcl-2 antagonists has provided highly effective options with acceptable toxicity. This manuscript summarizes the current evidence of the available treatment options and proposes an integrated algorithm for the frontline therapy of CLL.

Liver dysfunction in chronic lymphocytic leukemia: Prevalence, outcomes, and pathological findings

The prevalence of liver dysfunction and its association with outcomes in patients with previously untreated chronic lymphocytic leukemia (CLL) is unknown. Newly diagnosed (<12 months) previously untreated CLL patients seen at Mayo Clinic, Rochester, MN between 9/1993 and 4/2016 who had baseline assessment of at least one liver function test (LFT) were included in this analysis. The prevalence of liver dysfunction at baseline, proportion of patients who acquired LFT abnormalities, time to first therapy (TTFT) and overall survival (OS) were assessed. An abnormal LFT was present in 82/2336 (3.5%) patients at diagnosis and was associated with advanced Rai stage (Rai III-IV) (21% vs. 6%; P < .001), lower hemoglobin (13.1 g/dL vs. 13.9 g/dL; P < .001), and lower platelet count (187 × 109/L vs. 200 × 109/L; P = .03). Additionally, 236 patients with normal LFTs at diagnosis developed acquired liver dysfunction during follow-up. Patients with abnormal LFTs at diagnosis had a shorter OS compared to those with normal LFTs (HR 1.80 95% CI 1.13-2.87; P = .014, adjusted for age, sex, Rai stage, and treatment), although TTFT was not different. Of 52 patients who underwent a liver biopsy, CLL was present in liver tissue in 39/52 (73%) patients, with the portal tracts the most common region involved. Histopathology findings of liver involvement by CLL had limited correlation with choice of CLL therapy. In conclusion, approximately 1 of 25 newly diagnosed CLL patients has abnormal LFTs at diagnosis. Although the TTFT was not different among patients with abnormal LFTs, these patients have a shorter OS compared to those with normal LFTs.

Ibrutinib-Associated Nail Plate Abnormalities: Case Reports and Review

Chronic lymphocytic leukemia is a lymphoproliferative disorder characterized by a gradual accumulation of neoplastic B-lymphocytes. Ibrutinib is a novel therapy for chronic lymphocytic leukemia. Ibrutinib therapy has been associated with nail plate abnormalities. Other common cutaneous adverse events caused by ibrutinib appear to be bruising, hair changes, pruritus, and rashes. We describe the clinical features of two patients with chronic lymphocytic leukemia: a 79-year-old woman and a 53-year-old man who developed nail plate abnormalities approximately 6 and 4 months, respectively, after beginning ibrutinib therapy. We also review the characteristics of other patients with chronic lymphocytic leukemia with ibrutinib-associated nail plate abnormalities. The PubMed database was used to search the following terms: abnormal, abnormalities, adverse, brittle, chronic, cutaneous, dystrophy, events, effects, ibrutinib, lymphocytic, leukemia, nail, plate, and side. The relevant referenced papers generated by the search were reviewed. In conclusion, ibrutinib is used to treat chronic lymphocytic leukemia. It is usually well-tolerated. Many patients receiving ibrutinib will develop nail plate abnormalities. This adverse event is not a drug-limiting toxicity.

Predictive and prognostic biomarkers in the era of new targeted therapies for chronic lymphocytic leukemia

Treatment options for chronic lymphocytic leukemia (CLL) have improved with the introduction of the B-cell receptor inhibitors ibrutinib and idelalisib, and of the BCL2 inhibitor venetoclax. While awaiting the results of head to head comparisons between novel agents and chemoimmunotherapy, predictive biomarkers can assist physicians in treatment tailoring. Though novel agents have modified the landscape of predictors at the time of treatment requirement, the usefulness of historical CLL prognostic biomarkers is still up-to-date when considering anticipation of time to first treatment. This review discusses: (i) disease-related (TP53 defects, immunoglobulin gene mutations), therapy-related (duration of remission), and patient-related (age, comorbidities) biomarkers that can be used in the clinical practice to inform CLL treatment decision either at the time of first line therapy and disease relapse; and (ii) the need of new biomarkers to re-define high-risk CLL because of the questioning by novel agents of historical prognostic factors.