Serum beta(2)-microglobulin and serum thymidine kinase are independent predictors of progression-free survival in chronic lymphocytic leukemia and immunocytoma

Reassessing the chronic lymphocytic leukemia International Prognostic Index in the era of targeted therapies

ABSTRACT

We evaluated the chronic lymphocytic leukemia International Prognostic Index (CLL-IPI) in patients with CLL treated first line with targeted drugs (n = 991) or chemoimmunotherapy (n = 1256). With a median observation time of 40.5 months, the 3-year progression-free survival (PFS) rates for targeted drug-treated patients varied by CLL-IPI risk group: 96.5% (low), 87.6% (intermediate), 82.4% (high), and 78.7% (very high). Differences between consecutive CLL-IPI risk groups were observed for intermediate vs low and high vs intermediate, but not very high vs high. CLL-IPI factors β2-microglobulin, immunoglobulin heavy variable (IGHV) status, and TP53 status each retained prognostic value for PFS. The 3-year overall survival (OS) rates by CLL-IPI risk groups were 100%, 96%, 93.9%, and 89.4%, respectively, with no differences between consecutive risk groups. Age, Binet stage, β2-microglobulin, and TP53 status each retained prognostic value for OS. In chemoimmunotherapy patients (median observation time, 66.9 months), 3-year PFS rates for CLL-IPI risk groups were 78.1%, 51.4%, 40.1%, and 16.5%, respectively; corresponding 3-year OS rates were 97.4%, 93.1%, 81.8%, and 57.3%. In a matched-pair analysis, PFS differences in targeted therapies (n = 812) vs chemoimmunotherapy (n = 812) across all risk groups and OS differences in all but patients at low risk were demonstrated. The CLL-IPI maintains its prognostic value in predicting PFS outcomes with targeted drugs, but its impact in predicting survival appears diminished. Targeted therapies showed enhanced outcomes over chemoimmunotherapy, highlighting their effectiveness across various risk groups. Our findings support ongoing assessment of prognostic tools in CLL treatment evolution. These trials were registered at www.ClinicalTrials.gov as #NCT02345863, #NCT02401503, #NCT02689141, #NCT02445131, #NCT02758665, #NCT02950051, #NCT02242942, #NCT00262782, #NCT00281918, and #NCT01010061.

Mice Overexpressing Wild-Type RRAS2 Are a Novel Model for Preclinical Testing of Anti-Chronic Lymphocytic Leukemia Therapies

B-cell chronic lymphocytic leukemia (B-CLL) is the most common type of leukemia in the Western world. Mutation in different genes, such as TP53 and ATM, and deletions at specific chromosomic regions, among which are 11q or 17p, have been described to be associated to worse disease prognosis. Recent research from our group has demonstrated that, contrary to what is the usual cancer development process through missense mutations, B-CLL is driven by the overexpression of the small GTPase RRAS2 in its wild-type form without activating mutations. Some mouse models of this disease have been developed to date and are commonly used in B-CLL research, but they present different disadvantages such as the long waiting period until the leukemia fully develops, the need to do cell engraftment or, in some cases, the fact that the model does not recapitulate the alterations found in human patients. We have recently described Rosa26-RRAS2fl/flxmb1-Cre as a new mouse model of B-CLL with a full penetrance of the disease. In this work, we have validated this mouse model as a novel tool for the development of new therapies for B-CLL, by testing two of the most broadly applied targeted agents: ibrutinib and venetoclax. This also opens the door to new targeted agents against R-RAS2 itself, an approach not yet explored in the clinic.

Expert consensus on the management of chronic lymphocytic leukaemia in Asia

In recent years, considerable progress has been made in the standard treatment for chronic lymphocytic leukaemia (CLL) due to the availability of new potent drugs. However, the majority of data on CLL were derived from Western populations, with limited studies and guidelines on the management of CLL from an Asian population perspective. This consensus guideline aims to understand treatment challenges and suggest appropriate management approaches for CLL in the Asian population and other countries with a similar socio-economic profile. The following recommendations are based on a consensus by experts and an extensive literature review and contribute towards uniform patient care in Asia.

How I Manage Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL), is a hematologic malignancy characterized by the uncontrolled proliferation of mature B lymphocytes. CLL is the most prevalent leukemia in Western countries. Its presentation can range from asymptomatic with the incidental finding of absolute lymphocytosis on a routine blood test, to symptomatic disease requiring immediate intervention. Prognosis of the disease is defined by the presence or absence of specific mutations such as TP53, chromosomal abnormalities such as del(17p), a type of IGHV mutational status, and elevation of B2M and LDH. Treatment of CLL in the United States and Europe has evolved over the recent years thanks to the development of targeted therapies. The standard of care has shifted from traditional chemoimmunotherapy approaches to targeted therapies including Bruton tyrosine kinase inhibitors (BTKis) and BCL2 inhibitors, administered either as monotherapy or in combination with CD20 monoclonal antibodies. Several clinical trials have also recently evaluated combinations of BTKi and venetoclax and showed the combination to be well tolerated and able to induce deep remissions. Targeted therapies have a good safety profile overall; however, they also have unique toxicities that are important to recognize. Diarrhea, fatigue, arthralgia, infections, cytopenias, bleeding, and cardiovascular toxicities (including atrial fibrillation, ventricular arrhythmias, and hypertension) are the adverse events (AEs) commonly associated with BTKis. Initiation of therapy with venetoclax requires close monitoring because of the risk for tumor lysis syndrome associated with this agent, particularly in patients with a high disease burden. Development of newer target therapies is ongoing and the therapeutic landscape in CLL is expanding rapidly.

Time to second treatment can be used to predict overall survival in chronic lymphocytic leukemia: identifying risk factors to help guide treatment selection

Targeted therapies have largely replaced chemoimmunotherapy (CIT) in first-line treatment of chronic lymphocytic leukemia (CLL). We aimed to develop a prognostic model to determine who would benefit from first-line CIT vs target therapy. In follicular lymphoma, time from diagnosis to second treatment (TT2T) correlates better with overall survival (OS) than time from diagnosis to first treatment (TT1T). We hypothesized that TT2T is a potential surrogate for OS in CLL. In a model-building cohort (n = 298), we evaluated potential predictors for TT2T and derived a risk score, which we validated in an external cohort (n = 1141). Our data demonstrated that TT2T and OS were more strongly correlated than TT1T and OS. Our risk score model consisted of three predictors (unmutated IGHV, β2-microglobulin >297 nmol/L, and Rai stage I-IV), and was prognostic for TT2T and OS. TT2T is a promising surrogate for OS in CLL, but further validation is needed to establish this association.

Prognostic markers in patients with chronic lymphocytic leukaemia on targeted therapy, chemoimmunotherapy with anti-CD20 monoclonal antibody: a systematic review and meta-analysis of prognostic factors

Combination chemoimmunotherapy (CIT) consisting of anti-CD20 has improved the progression-free survival (PFS) and overall survival (OS) of patients with chronic lymphocytic leukaemia (CLL). We performed a comprehensive synthesis of prognostic factors in patients with CLL on combined CIT with anti-CD20 antibodies compared with standard chemotherapy alone or targeted therapy.We searched the MEDLINE and academic search complete electronic databases as well as clinicaltrials.gov (from inception up to 01 August 2022) for randomised controlled trials examining chemoimmunotherapy and targeted therapy in patients with CLL. The risk of bias and the quality of evidence was assessed using the quality in prognostic studies tool (QUIPS).A total of 10 prognostic factors were identified and evaluated in patients with CLL on anti-CD20 antibody-containing CIT. The predictive value of the following prognostic factors was confirmed and associated with poor patient outcomes; deletion 17p (HR = 3.39), Immunoglobulin heavy chain variable region gene mutation status (HR = 0.96) and β_2-microglobulin (HR = 1.41).Conventional predictive factors may have retained prognostic value and could be useful in the stratification of patients who may be non-responsive to CIT.Trial registration: International Prospective Register of Systematic Reviews (PROSPERO) registry (CRD42021218997).

Super-Enhancer–Associated nine-gene prognostic score model for prediction of survival in chronic lymphocytic leukemia patients

Chronic lymphocytic leukemia (CLL) is a type of highly heterogeneous mature B-cell malignancy with various disease courses. Although a multitude of prognostic markers in CLL have been reported, insights into the role of super-enhancer (SE)–related risk indicators in the occurrence and development of CLL are still lacking. A super-enhancer (SE) is a cluster of enhancers involved in cell differentiation and tumorigenesis, and is one of the promising therapeutic targets for cancer therapy in recent years. In our study, the CLL-related super-enhancers in the training database were processed by LASSO-penalized Cox regression analysis to screen a nine-gene prognostic model including TCF7, VEGFA, MNT, GMIP, SLAMF1, TNFRSF25, GRWD1, SLC6AC, and LAG3. The SE-related risk score was further constructed and it was found that the predictive performance with overall survival and time-to-treatment (TTT) was satisfactory. Moreover, a high correlation was found between the risk score and already known prognostic markers of CLL. In the meantime, we noticed that the expressions of TCF7, GMIP, SLAMF1, TNFRSF25, and LAG3 in CLL were different from those of healthy donors (p < 0.01). Moreover, the risk score and LAG3 level of matched pairs before and after treatment samples varied significantly. Finally, an interactive nomogram consisting of the nine-gene risk group and four clinical traits was established. The inhibitors of mTOR and cyclin-dependent kinases (CDKs) were considered effective in patients in the high-risk group according to the pRRophetic algorithm. Collectively, the SE-associated nine-gene prognostic model developed here may be used to predict the prognosis and assist in the risk stratification and treatment of CLL patients in the future.

Serum B-Cell Maturation Antigen is an Independent Prognostic Marker in Previously Untreated Chronic Lymphocytic Leukemia

B-cell maturation antigen (BCMA) is a cell membrane receptor expressed on mature B lymphocytes with elevated serum levels found among patients with B-cell malignancies, including chronic lymphocytic leukemia (CLL). Serum BCMA (sBCMA) levels were measured in 331 untreated, newly diagnosed CLL patients using an ELISA with a polyclonal anti-BCMA antibody. Elevated sBCMA was found among patients with CLL compared to age- and sex-matched healthy controls and those with more active CLL based on prognostic factors. The relationships between sBCMA, time to first treatment (TTFT), overall survival (OS) and multiple prognostic factors were compared using Mann Whitney and Kruskal-Wallis tests. The median sBCMA level in the CLL cohort (48.6 ng/mL) was significantly higher (p < 0.001) compared to age- and sex-matched healthy subjects (n = 100; 37.8 ng/mL). sBCMA correlated with TTFT (hazard ratio [HR] 2.9, 95% confidence interval [CI] 2.0-4.2, p < 0.001) and OS (HR 2.5, 95% CI 1.5-4.0, p < 0.001). Multiple models were utilized to test the predictive effects of sBCMA, sex, CLL-IPI and IPS-E on TTFT and OS. The addition of sBCMA to CLL-IPI and IPS-E improved their prognostic ability to predict TTFT and OS. Thus, serum BCMA is a new promising prognostic biomarker for CLL.

Detailing the epidemiological and clinical characteristics of chronic lymphocytic leukaemia in Portugal-Results from a population-based cancer registry cohort study

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia among adults in western countries. Considering the increasing incidence and prevalence of this condition, it is highly relevant to better characterise these patients in Portugal, where data is still scarce.

METHODS

To determine incidence, clinical presentation, survival and second malignancies, a population-based historical cohort study was conducted. Cases of interest were identified through the South Region Cancer Registry database and additional data sources. Patients aged ≥18 years, with a confirmed diagnosis of CLL or small lymphocytic lymphoma between January 1st, 2013 and December 31st, 2014 were included. Patients were followed-up until death or cut-off date (December 31st, 2019).

RESULTS

A total of 496 patients were included and median follow-up time was 5.46 years. Crude incidence rates were 5.03 and 5.22 per 100,000 inhabitants for 2013 and 2014, respectively, and age-adjusted incidence rates were 3.18:100,000 European population for 2013 and 3.35:100,000 European population for 2014. Median age at diagnosis was 71 years and the male/female ratio was 1.40. The majority of patients had leukemic presentation of the disease (86.09%), was diagnosed in Binet stage A (75.58%) and did not present B symptoms (84.01%), anaemia (haemoglobin ≤10g/dL; 90.63%) nor thrombocytopenia (platelet count ≤100 000/μL; 91.73%). Five-year overall survival (OS) rate was 70.53% (95%CI 66.31-74.34) and age, lactate dehydrogenase, Binet stage and a ≥5 Charlson comorbidity index score were independently associated with OS. Standardised-incidence ratios for any second malignancy and cutaneous squamous cell carcinoma were 1.59 (95%CI 1.19-2.08) and 10.15 (95%CI 6.28-15.51), respectively.

CONCLUSION

Incidence, clinical presentation and survival of CLL Portuguese patients are similar to those reported for other western countries. The increased risk of second malignancies raises concerns and needs adequate clinical watchfulness.

The Evolving Landscape of Chronic Lymphocytic Leukemia on Diagnosis, Prognosis and Treatment

The knowledge of chronic lymphocytic leukemia (CLL) has progressively deepened during the last forty years. Research activities and clinical studies have been remarkably fruitful in novel findings elucidating multiple aspects of the pathogenesis of the disease, improving CLL diagnosis, prognosis and treatment. Whereas the diagnostic criteria for CLL have not substantially changed over time, prognostication has experienced an expansion with the identification of new biological and genetic biomarkers. Thanks to next-generation sequencing (NGS), an unprecedented number of gene mutations were identified with potential prognostic and predictive value in the 2010s, although significant work on their validation is still required before they can be used in a routine clinical setting. In terms of treatment, there has been an impressive explosion of new approaches based on targeted therapies for CLL patients during the last decade. In this current chemotherapy-free era, BCR and BCL2 inhibitors have changed the management of CLL patients and clearly improved their prognosis and quality of life. In this review, we provide an overview of these novel advances, as well as point out questions that should be further addressed to continue improving the outcomes of patients.

Incorporating molecular biomarkers into the continuum of care in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy characterized by marked heterogeneity. Discoveries in disease biology over the past two decades have helped explain clinical variability and heralded the arrival of the targeted therapy era. In this article, we review improvements in risk stratification which have coincided with this progress, including individual biomarkers and their incorporation into prognostic models. Amidst an ever-expanding list of biomarkers, we seek to bring focus to the essential tests to improve patient care and counseling at particular times in the disease course, beginning with prognosis at diagnosis. The majority of patients do not require treatment at the time of diagnosis, making time-to-first-treatment a key initial prognostic concern. Prognostic and predictive biomarkers are then considered at subsequent major junctures, including at the time of treatment initiation, while on therapy, and at the time of relapse on novel agents.

Prognostic impact of prevalent chronic lymphocytic leukemia stereotyped subsets: analysis within prospective clinical trials of the German CLL Study Group (GCLLSG)

Almost one-third of all patients with chronic lymphocytic leukemia (CLL) express stereotyped B cell receptor immunoglobulins (BcR IG) and can be assigned to distinct subsets, each with a particular BcR IG. The largest stereotyped subsets are #1, #2, #4 and #8, associated with specific clinicobiological characteristics and outcomes in retrospective studies. We assessed the associations and prognostic value of these BcR IG in prospective multicenter clinical trials reflective of two different clinical situations: i) early-stage patients (watch-and-wait arm of the CLL1 trial) (n=592); ii) patients in need of treatment, enrolled in 3 phase III trials (CLL8, CLL10, CLL11), treated with different chemo-immunotherapies (n=1861). Subset #1 was associated with del(11q), higher CLL international prognostic index (CLL-IPI) scores and similar clinical course to CLL with unmutated immunoglobulin heavy variable (IGHV) genes (U-CLL) in both early and advanced stage groups. IGHV-mutated (M-CLL) subset #2 cases had shorter time-to-first-treatment (TTFT) versus other M-CLL cases in the early-stage cohort (HR: 4.2, CI: 2-8.6, p<0.001), and shorter time-to-next-treatment (TTNT) in the advanced-stage cohort (HR: 2, CI: 1.2-3.3, p=0.005). M-CLL subset #4 was associated with lower CLL-IPI scores and younger age at diagnosis; in both cohorts, these patients showed a trend towards better outcomes versus other M-CLL. U-CLL subset #8 was associated with trisomy 12. Overall, this study shows that major stereotyped subsets have distinctive characteristics. For the first time in prospective multicenter clinical trials, subset # 2 appeared as an independent prognostic factor for earlier TTFT and TTNT and should be proposed for risk stratification of patients.

Recent progress of prognostic biomarkers and risk scoring systems in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia with high heterogeneity in the western world. Thus, investigators identified a number of prognostic biomarkers and scoring systems to guide treatment decisions and validated them in the context of immunochemotherapy. A better understanding of prognostic biomarkers, including serum markers, flow cytometry outcomes, IGHV mutation status, microRNAs, chromosome aberrations and gene mutations, have contributed to prognosis in CLL. Del17p/ TP53 mutation, NOTCH1 mutation, CD49d, IGHV mutation status, complex karyotypes and microRNAs were reported to be of predictive values to guide clinical decisions. Based on the biomarkers above, classic prognostic models, such as the Rai and Binet staging systems, MDACC nomogram, GCLLSG model and CLL-IPI, were developed to improve risk stratification and tailor treatment intensity. Considering the presence of novel agents, many investigators validated the conventional prognostic biomarkers in the setting of novel agents and only TP53 mutation status/del 17p and CD49d expression were reported to be of prognostic value. Whether other prognostic indicators and models can be used in the context of novel agents, further studies are required.

A laboratory-based scoring system predicts early treatment in Rai 0 chronic lymphocytic leukemia

We present a laboratory-based prognostic calculator (designated CRO score) to risk stratify treatment-free survival in early stage (Rai 0) chronic lymphocytic leukemia (CLL) developed using a training-validation model in a series of 1,879 cases from Italy, the United Kingdom and the United States. By means of regression analysis, we identified five prognostic variables with weighting as follows: deletion of the short arm of chromosome 17 and unmutated immunoglobulin heavy chain gene status, 2 points; deletion of the long arm of chromosome 11, trisomy of chromosome 12, and white blood cell count >32.0x103/microliter, 1 point. Low-, intermediate- and high-risk categories were established by recursive partitioning in a training cohort of 478 cases, and then validated in four independent cohorts of 144 / 395 / 540 / 322 cases, as well as in the composite validation cohort. Concordance indices were 0.75 in the training cohort and ranged from 0.63 to 0.74 in the four validation cohorts (0.69 in the composite validation cohort). These findings advocate potential application of our novel prognostic calculator to better stratify early-stage CLL, and aid case selection in risk-adapted treatment for early disease. Furthermore, they support immunocytogenetic analysis in Rai 0 CLL being performed at the time of diagnosis to aid prognosis and treatment, particularly in today's chemofree era.

Novel Therapies in Chronic Lymphocytic Leukemia: A Rapidly Changing Landscape

OPINION STATEMENT

Treatment landscape of chronic lymphocytic leukemia (CLL) has changed since 2014 after the introduction of inhibitors of B-cell receptor signaling pathway (ibrutinib, acalabrutinib, idelalisib and duvelisib) and the inhibitor of the anti-apoptotic protein BCL-2 (venetoclax). In 2019, novel agents were upgraded from being a "great treatment option" to the "preferred choice" for all lines of treatment after number of randomized clinical trials proved their superiority compared to conventional chemoimmunotherapy (CIT) regimens. A growing number of next-generation molecules are in clinical trials with a promise of improved efficacy and less toxicity. This includes agents with expected better safety profile (zanubrutinib, umbralisib, etc.) or more importantly with a potential to overcome the resistance mechanism to early generation agents (ARQ-531, LOXO-305, or vecabrutinib). Early intervention has once again become an active topic of research and, if proven to provide an overall survival benefit, will eliminate the "watch and wait" strategy for asymptomatic CLL patients. Until then, treatment should only be offered to patients who meet the standard treatment indication in standard practice. With our upgraded therapeutic toolbox, there are and will be many unanswered questions. CLL field will need to define the optimal treatment sequence and most effective combinations with a goal of having a time-limited and chemotherapy-free regimen that provides longest remissions and potentially cure. Cellular immunotherapy with chimeric antigen receptor T-cell (CAR-T) may become available for high-risk CLL along with allogeneic stem cell transplant (allo-SCT). Financial toxicity of novel agents especially when used in combination will need to be an important aspect of research in coming years to avoid unnecessary overtreatment of patients. As current prognostic models (CLL-IPI, etc.) were developed and validated in the CIT era, there is ongoing effort to develop new models using clinical and molecular characteristics to accurately define high-risk CLL in the era of novel agents. We all need to keep in mind that access to the novel agents is currently limited to certain developed countries and every effort should be made to make sure patients around the world also benefit from these outstanding drugs.

Prognostic model for newly diagnosed CLL patients in Binet stage A: results of the multicenter, prospective CLL1 trial of the German CLL study group

The heterogeneity of early stage CLL challenges prognostication, and refinement of prognostic indices for risk-adapted management in this population is essential. The aim of the multicenter, prospective CLL1 trial was to explore a novel prognostic model (CLL1-PM) developed to identify risk groups, separating patients with favorable from others with dismal prognosis. A cohort of 539 clinically, biochemically, and genetically characterized Binet stage A patients were observed until progression, first-line treatment, or death. Multivariate analysis identified six independent factors associated with overall survival (OS) and time-to-first treatment (TTFT): del(17p), unmutated IGHV, del(11q), ß2-microglobulin >3.5 mg/dL, lymphocyte doubling time (LDT) <12 months, and age >60 years. These factors were integrated into the CLL1-PM, which stratified patients into four risk groups. The CLL1-PM was prognostic for OS and TTFT, e.g., the risk of treatment at 5 years was 85.9, 51.8, 27.6, and 11.3% for very low (0-1.5), low (2-4), high (4.5-6.5), and very high-risk (7-14) scores, respectively (P < 0.001). Notably, in addition to factors comprising CLL-IPI, we substantiated del(11q) and LDT as prognostic factors in early CLL. Altogether, our findings would be useful to effectively stratify Binet stage A patients, particularly within the scope of clinical trials evaluating novel agents.

[Characteristics of chronic lymphocytic leukemia in Togo]

The epidemiological, clinical and biological characteristics of chronic lymphocytic leukemia (CLL) are little studied in Togo. The purpose of this study was to describe these characteristics at the time of diagnosis. We conducted a retrospective and descriptive study of patients diagnosed at the University Hospital Campus from January 1999 to December 2018. Over the past two decades, 87 patients were seen for CLL (20% of patients with hematological malignancies) with an annual prevalence of 4.35 new cases. The average age of patients was 61 +/- 12,48 years (ranging from 17-85 years); 55 women and 32 men (sex ratio M/F 0.58) were enrolled. Clinically, 16 patients (18%) had no tumor syndrome, 33 patients (38%) had lymphadenopathy, 62 patients (71%) splenomegaly and 23 patients (26%) hepatomegaly. Biologically, the mean blood and medullary lymphocyte count was 87188/mm3 (ranging from 7000-481780/mm3) and 75.75% +/- 12,88 (ranging from 44,5-96,5%) respectively; 65 patients (75%) had haemoglobin less than 10g/dl and 20 patients (23%) had platelet count below 100000/mm3. At the time of diagnosis, 67 patients (77%) had Binet stage C, 7 patients (8%) stage B and 13 patients (15%) stage A. The study of biological prognostics factors showed that 66% of cases had β2-microglobulin level higher than normal and 95% of cases had LDH higher than normal. CLL is a reality in Togo with a predominance of women and an average age of 61 years. Most patients are seen at Binet stage C and their assessment has revealed huge tumor mass with increased LDH and β2-microglobulin. The current follow-up of these patients will enable us to assess their overall survival.

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.

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.

Chronic lymphocytic leukaemia

Important advances in understanding the pathogenesis of chronic lymphocytic leukaemia in the past two decades have led to the development of new prognostic tools and novel targeted therapies that have improved clinical outcome. Chronic lymphocytic leukaemia is the most common type of leukaemia in developed countries, and the median age at diagnosis is 72 years. The criteria for initiating treatment rely on the Rai and Binet staging systems and on the presence of disease-related symptoms. For many patients with chronic lymphocytic leukaemia, treatment with chemotherapy and anti-CD20 monoclonal antibodies is the standard of care. The impressive efficacy of kinase inhibitors ibrutinib and idelalisib and the BCL-2 antagonist venetoclax have changed the standard of care in specific subsets of patients. In this Seminar, we review the recent progress in the management of chronic lymphocytic leukaemia and highlight new questions surrounding the optimal disease management.

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.

B-cell Receptor Signaling Regulates Metabolism in Chronic Lymphocytic Leukemia

Peripheral blood chronic lymphocytic leukemia (CLL) cells are quiescent but have active transcription and translation processes, suggesting that these lymphocytes are metabolically active. Based on this premise, the metabolic phenotype of CLL lymphocytes was investigated by evaluating the two intracellular ATP-generating pathways. Metabolic flux was assessed by measuring glycolysis as extracellular acidification rate (ECAR) and mitochondrial oxidative phosphorylation as oxygen consumption rate (OCR) and then correlated with prognostic factors. Further, the impact of B-cell receptor signaling (BCR) on metabolism was determined by genetic ablation and pharmacological inhibitors. Compared with proliferative B-cell lines, metabolic fluxes of oxygen and lactate were low in CLL cells. ECAR was consistently low, but OCR varied considerably in human patient samples (n = 45). Higher OCR was associated with poor prognostic factors such as ZAP 70 positivity, unmutated IGHV, high β2M levels, and higher Rai stage. Consistent with the association of ZAP 70 and IGHV unmutated status with active BCR signaling, genetic ablation of BCR mitigated OCR in malignant B cells. Similarly, knocking out PI3Kδ, a critical component of the BCR pathway, decreased OCR and ECAR. In concert, PI3K pathway inhibitors dramatically reduced OCR and ECAR. In harmony with a decline in metabolic activity, the ribonucleotide pools in CLL cells were reduced with duvelisib treatment. Collectively, these data demonstrate that CLL metabolism, especially OCR, is linked to prognostic factors and is curbed by BCR and PI3K pathway inhibition.Implications: This study identifies a relationship between oxidative phosphorylation in CLL and prognostic factors providing a rationale to therapeutically target these processes. Mol Cancer Res; 15(12); 1692-703. ©2017 AACR.

Comparative Efficacy of Ibrutinib Versus Obinutuzumab + Chlorambucil in First-Line Treatment of Chronic Lymphocytic Leukemia: A Matching-Adjusted Indirect Comparison

INTRODUCTION

Ibrutinib (ibr) monotherapy and the combination of obinutuzumab plus chlorambucil (obi) are approved for previously untreated chronic lymphocytic leukemia (CLL). No trials directly comparing their efficacy are available. Therefore a matching-adjusted indirect comparison (MAIC) was performed to provide insight into their relative efficacy in terms of progression-free survival (PFS) and overall survival (OS). MAIC attempts to adjust for between-trial differences in factors known or suspected to influence treatment effects, to minimize bias.

METHODS

A MAIC within a Bayesian framework was conducted using individual patient data from the RESONATE-2 study of ibr versus chlorambucil and published data from the CLL11 study of obi versus chlorambucil. Both studies were conducted in patients ineligible for full-dose fludarabine-based therapy. After matching, the reweighted adjusted relative efficacy measure of ibr versus chlorambucil from RESONATE-2 [hazard ratio (HR), 95% credible interval (CrI)] was compared with that of obi versus chlorambucil from CLL11 for each endpoint, using a Bayesian indirect comparison.

RESULTS

Our results suggest that in a population with similar average baseline characteristics to CLL11, ibr would improve PFS and OS outcomes compared to obi. Before matching, the HRs for ibr versus obi were 0.48 [CrI = 0.22-1.02, p(HR <1) = 97%], 0.85 [CrI = 0.44-1.63, p(HR <1) = 69%], and 0.40 [CrI = 0.10-1.54, p(HR <1) = 91%] for PFS by investigator assessment, PFS by independent review committee, and OS, respectively. After matching on all available characteristics the HRs decreased to 0.12 [CrI = 0.02-0.97, p(HR <1) = 98%], 0.24 [CrI = 0.04-1.35, p(HR <1) = 95%], and 0.21 [CrI = <0.01-8.89, p(HR <1) = 79%], respectively. There was a large variance around the treatment effect for OS due to the low number of deaths.

CONCLUSION

Our analysis suggests that ibrutinib is highly likely to provide greater PFS benefit than obinutuzumab plus chlorambucil in older or less fit patients with previously untreated CLL. There is also an indication of improvement in OS, albeit with a higher uncertainty due to the low number of events.

FUNDING

Janssen-Cilag Ltd.

Long-term follow-up of patients receiving allogeneic stem cell transplant for chronic lymphocytic leukaemia: mixed T-cell chimerism is associated with high relapse risk and inferior survival

There is limited information regarding the immunological predictors of post-allogeneic stem cell transplant (alloSCT) outcome in chronic lymphocytic leukaemia (CLL), such as mixed T-cell chimerism. We analysed 143 consecutive patients with relapsed/refractory CLL, transplanted between 2000 and 2012, to determine the prognostic relevance of mixed chimerism post-alloSCT and the ability of post-transplant immunomodulation to treat relapse. Mixed T-cell chimerism occurred in 50% of patients at 3 months and 43% at 6 months post-alloSCT; upon 3- and 6-month landmark analysis, this was associated with inferior progression-free survival (PFS) [Hazard ratio (HR) 1·93, P = 0·003 and HR 2·58, P < 0·001] and survival (HR 1·66, P = 0·05 and HR 2·17, P < 0·001), independent of baseline patient characteristics, and a lower rate of grade II-IV acute graft-versus-host disease (GHVD) (16% vs. 52%, P < 0·001). Thirty-three patients were treated with immunomodulation for relapse post-alloSCT (immunosuppression withdrawal, n = 6, donor lymphocyte infusion, n = 27); 17 achieved complete response (CR), which predicted superior PFS (53 months vs. 10 months, P < 0·001) and survival (117 months vs. 30 months, P = 0·006). Relapsed patients with mixed chimerism had inferior response to immunomodulation; conversion to full donor chimerism was highly correlated both with CR and with the development of severe acute GVHD, which was fatal in 3/8 patients. Novel therapeutic strategies are required for patients with mixed T-cell chimerism post-alloSCT for CLL.

TP53 Staining in Tissue Samples of Chronic Lymphocytic Lymphoma Cases: An Immunohistochemical Survey of 51 Cases

Objective:

Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disease in adults. The aim of this study is to find out if the extent of proliferation centers or the immunohistochemical expression of p53 is related to disease prognosis.

Materials and Methods:

In the scope of this study, 54 biopsy specimens from 51 patients (50 of lymph nodes; the others of spleen, tonsil, orbit, and liver) diagnosed with CLL at the Hacettepe University Department of Pathology in 2000-2013 were reevaluated. The clinical and demographic data of the patients were obtained from our patient database. Biopsy samples were assessed semi-quantitatively for the percentage of proliferation center/total biopsy area (PC/TBA) and an immunohistochemical study was performed on representative blocks of tissues for p53 expression.

Results:

When the patients were divided into two categories according to Rai stage as high and low (stages 0, 1, and 2 vs. stages 3 and 4), it was seen that patients with low Rai stage had a better prognosis than those with high stages (p=0.030). However, there was no statistically significant correlation between overall survival and PC/TBA ratio or p53 expression levels.

Conclusion:

In our cohort, PC/TBA ratio and immunopositivity of p53 did not show correlations with overall survival.

Chronic Lymphocytic Leukemia Prognostic Index: A New Integrated Scoring System to Predict the Time to First Treatment in Chinese Patients with Chronic Lymphocytic Leukemia

BACKGROUND

The established clinical staging systems (Rai/Binet) of chronic lymphocytic leukemia (CLL) cannot accurately predict the appropriate treatment of patients in the earlier stages. In the past two decades, several prognostic factors have been identified to predict the outcome of patients with CLL, but only a few studies investigated more markers together. To predict the time to first treatment (TTFT) in patients of early stages, we evaluated the prognostic role of conventional markers as well as cytogenetic abnormalities and combined them together in a new prognostic scoring system, the CLL prognostic index (CLL-PI).

METHODS

Taking advantage of a population of 406 untreated Chinese patients with CLL at early and advanced stage of disease, we identified the strongest prognostic markers of TTFT and, subsequently, in a cohort of 173 patients who had complete data for all 3 variables, we integrated the data of traditional staging system, cytogenetic aberrations, and mutational status of immunoglobulin heavy chain variable region (IGHV) in CLL-PI. The median follow-up time was 45 months and the end point was TTFT.

RESULTS

The median TTFT was 38 months and the 5-year overall survival was 80%. According to univariate analysis, patients of advanced Rai stages (P < 0.001) or with 11q- (P = 0.002), 17p- (P < 0.001), unmutated IGHV (P < 0.001), negative 13q- (P = 0.007) and elevated lactate dehydrogenase levels (P = 0.001) tended to have a significantly shorter TTFT. And subsequently, based on multivariate Cox regression analysis, three independent factors for TTFT were identified: advanced clinical stage (P = 0.002), 17p- (P = 0.050) and unmutated IGHV (P = 0.049). Applying weighted grading of these independent factors, a CLL-PI was constructed based on regression parameters, which could categorize four different risk groups (low risk [score 0], intermediate low [score 1], intermediate high [score 2] and high risk [score 3-6]) with significantly different TTFT (median TTFT of not reached (NR), 65.0 months, 36.0 months and 19.0 months, respectively, P < 0.001).

CONCLUSIONS

This study developed a weighted, integrated CLL-PI prognostic system of CLL patients which combines the critical genetic prognostic markers with traditional clinical stage. This novel modified PI system could be used to discriminate among groups and may help predict the TTFT and prognosis of patients with CLL.

Chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is a malignancy of CD5+ B cells that is characterized by the accumulation of small, mature-appearing lymphocytes in the blood, marrow and lymphoid tissues. Signalling via surface immunoglobulin, which constitutes the major part of the B cell receptor, and several genetic alterations play a part in CLL pathogenesis, in addition to interactions between CLL cells and other cell types, such as stromal cells, T cells and nurse-like cells in the lymph nodes. The clinical progression of CLL is heterogeneous and ranges from patients who require treatment soon after diagnosis to others who do not require therapy for many years, if at all. Several factors, including the immunoglobulin heavy-chain variable region gene (IGHV) mutational status, genomic changes, patient age and the presence of comorbidities, should be considered when defining the optimal management strategies, which include chemotherapy, chemoimmunotherapy and/or drugs targeting B cell receptor signalling or inhibitors of apoptosis, such as BCL-2. Research on the biology of CLL has profoundly enhanced our ability to identify patients who are at higher risk for disease progression and our capacity to treat patients with drugs that selectively target distinctive phenotypic or physiological features of CLL. How these and other advances have shaped our current understanding and treatment of patients with CLL is the subject of this Primer.

Chemoimmunotherapy Versus Targeted Treatment in Chronic Lymphocytic Leukemia: When, How Long, How Much, and in Which Combination?

During the past 5 years, rapid therapeutic advances have changed the landscape of chronic lymphocytic leukemia (CLL) therapy. This disease has traditionally been treated using cytotoxic chemotherapy regimens in combination with anti-CD20 antibody treatment, and recent long-term follow-up data from multiple centers suggest that fit patients with CLL with favorable disease features-particularly mutated immunoglobulin heavy chain variable region (IGHV) genes-derive very long-term benefit from the most potent of these regimens, namely the fludarabine, cyclophosphamide, and rituximab (FCR) regimen. The advent of oral targeted therapies, particularly ibrutinib and idelalisib, has provided generally well-tolerated and highly effective additional options that have come into widespread use in the relapsed setting. Additional agents are advancing in clinical development, with the BCL-2 inhibitor venetoclax likely to be approved by the U.S. Food and Drug Administration (FDA) in 2016. With the development of these novel therapies for patients with relapsed CLL, many unanswered questions remain, including the optimal sequence (first vs. second line), duration, discontinuation, and combination of these agents. In addition, recent publications show the emergence of a pattern of treatment resistance in certain subgroups of patients with del(17p) and complex karyotype that needs further study and improvement. Because the field of CLL management has become much more complex, we focus here on understanding the recent data and discuss many of the questions and controversies important for how we approach patients with CLL.

Chronic Lymphocytic Leukemia in the Elderly, Which Investigations Are Necessary: A Map for the Practicing Oncologist

BACKGROUND

Chronic lymphocytic leukemia (CLL), the most prevalent leukemia in the Western world, is predominantly a disease of older individuals who also have other comorbidities as well as declining organ and bone marrow reserve. Although chemoimmunotherapy is the frontline therapy for fit CLL patients who can tolerate the therapy, many elderly patients cannot tolerate such intense therapy.

METHODS

The authors first reviewed the most recent findings concerning CLL cytogenetics, molecular biology, and prognostic models. They then surveyed recent and ongoing trials of novel CLL agents and strategies, with a focus on those most relevant to elderly patients.

RESULTS

Novel therapies, revised staging procedures, and careful assessment of individual patients' frailty and functional status will allow clinicians to provide optimal care management for older CLL patients.

CONCLUSION

Therapy for the elderly CLL population must be tailored to each patient's fitness level and comorbid conditions, with special consideration for the potential quality-of-life impacts of various treatment recommendations.

The prognostic significance of surface dipeptidylpeptidase IV (CD26) expression in B-cell chronic lymphocytic leukemia

A number of factors related to B-cell chronic lymphocytic leukemia (B-CLL) patients' prognosis have been identified. However, still some factors better reflecting disease activity in individual cases are explored. The study aimed to evaluate prognostic significance of dipeptidylpeptidase IV/CD26 expression on B-CLL cells and its relationship with other well established prognostic factors. The study included 94 patients with newly diagnosed B-CLL and involved analysis of clinical, laboratory, flow-cytometry and cytogenetic data. Detailed analysis showed that CD26 expression on B-CLL cells correlates with Rai's clinical stage of the disease at diagnosis (p=0.034), β2-microglobulin concentration (p=0.012), lactic acid dehydrogenase activity (p=0.045) and absolute lymphocytes' count (p=0.027) in the blood. The multivariate analysis revealed that time to treatment (TTT) was significantly influenced by Rai clinical stage, LDH activity in blood and CD26 expression on B-CLL cell's. Moreover, in the multivariate analysis restricted to the group of patients with documented cytogenetic risk (n=36) CD26 expression, Rai clinical stage and cytogenetic profile remained their independent impact on TTT. The results of our study indicate that the CD26 expression should be incorporated in B-CLL patients risk assessment along with well known prognostic factors, since it seems to have a relationship with the tumor mass and influences TTT.

An international prognostic index for patients with chronic lymphocytic leukaemia (CLL-IPI): a meta-analysis of individual patient data

BACKGROUND

The management of patients with chronic lymphocytic leukaemia is currently undergoing improvements due to novel therapies and a plethora of biological and genetic variables that add prognostic information to the classic clinical staging systems. We established an international consortium with the aim to create an international prognostic index for chronic lymphocytic leukaemia (CLL-IPI) that integrates the major prognostic parameters.

METHODS

We used results from a systematic search of the Cochrane Haematological Malignancies Group of MEDLINE, Embase, and Central databases for prospective, clinical phase 2 and 3 trials of chronic lymphocytic leukaemia, published between Jan 1, 1950, and Dec 31, 2010, which identified 13 trials. We contacted the principal investigators of these 13 trials, of which eight agreed to include individual patient data. We used the individual patient data from these phase 3 trials from France, Germany, Poland, the UK, and the USA to create the full analysis dataset. The full analysis dataset was randomly divided, using a random sample procedure, into training and internal-validation datasets. We did a univariate analysis and multivariate analyses using 27 baseline factors and overall survival as an endpoint. We assigned weighted risk scores to each factor included in the final multivariable model. We assessed the discriminatory value using C-statistics and also the validity and reproducibility of the CLL-IPI by subgroup analysis. We used two additional datasets from the Mayo Clinic (Rochester, MN, USA; MAYO cohort) and the SCALE Scandinavian population-based case-control study (SCAN cohort) as the external-validation datasets.

FINDINGS

3472 treatment-naive patients were included in the full analysis dataset; 2308 were randomly segregated into the training dataset and 1164 into the internal-validation dataset. 838 patients were included in the MAYO cohort and 416 in the SCAN cohort. Median age of patients in the full analysis dataset was 61 years (range 27-86). Five independent prognostic factors were identified in the training dataset: TP53 status (no abnormalities vs del[17p] or TP53 mutation or both), IGHV mutational status (mutated vs unmutated), serum β2-microglobulin concentration (≤3·5 mg/L vs >3·5 mg/L), clinical stage (Binet A or Rai 0 vs Binet B-C or Rai I-IV), and age (≤65 years vs >65 years). Using a weighted grading of the independent factors, a prognostic index was derived that identified four risk groups within the training dataset with significantly different overall survival at 5 years: low (93·2% [95% CI 90·5-96·0]), intermediate (79·3% [75·5-83·2]), high (63·3% [57·9-68·8]), and very high risk (23·3% [12·5-34·1]; log-rank test comparing survival across the four risk groups p<0·0001; C-statistic, c=0·723 [95% CI 0·684-0·752]). These risk groups were confirmed in the internal-validation and external-validation datasets.

INTERPRETATION

The CLL-IPI combines genetic, biochemical, and clinical parameters into a prognostic model, discriminating four prognostic subgroups. The CLL-IPI will allow a more targeted management of patients with chronic lymphocytic leukaemia in clinical practice and in trials testing novel drugs.

FUNDING

José Carreras Leukaemia Foundation.

Analysis of clinical prognostic variables for Chronic Lymphocytic Leukemia decision-making problems

INTRODUCTION

Chronic Lymphocytic Leukemia (CLL) is a disease with highly heterogeneous clinical course. A key goal is the prediction of patients with high risk of disease progression, which could benefit from an earlier or more intense treatment. In this work we introduce a simple methodology based on machine learning methods to help physicians in their decision making in different problems related to CLL.

MATERIAL AND METHODS

Clinical data belongs to a retrospective study of a cohort of 265 Caucasians who were diagnosed with CLL between 1997 and 2007 in Hospital Cabueñes (Asturias, Spain). Different machine learning methods were applied to find the shortest list of most discriminatory prognostic variables to predict the need of Chemotherapy Treatment and the development of an Autoimmune Disease.

RESULTS

Autoimmune disease occurrence was predicted with very high accuracy (>90%). Autoimmune disease development is currently an unpredictable severe complication of CLL. Chemotherapy Treatment has been predicted with a lower accuracy (80%). Risk analysis showed that the number of false positives and false negatives are well balanced.

CONCLUSIONS

Our study highlights the importance of prognostic variables associated with the characteristics of platelets, reticulocytes and natural killers, which are the main targets of the autoimmune haemolytic anemia and immune thrombocytopenia for autoimmune disease development, and also, the relevance of some clinical variables related with the immune characteristics of CLL patients that are not taking into account by current prognostic markers for predicting the need of chemotherapy. Because of its simplicity, this methodology could be implemented in spreadsheets.

Chronic lymphocytic leukemia (CLL)-Then and now

The field of chronic lymphocytic leukemia (CLL) has witnessed considerable change since the time clinical staging was introduced in clinical practice in 1975. Over the years, the prognostication in CLL has expanded with the addition in late 90s of mutational status of variable region of immunoglobulin heavy chain (IGHV), and chromosomal analyses using fluorescent in situ hybridization (FISH). More recently, stereotypy of BCR (B cell receptor) and whole exome sequencing (WES) based discovery of specific mutations such as NOTCH1, TP53, SF3B1, XPO-1, BIRC3, ATM, and RPS15 further refined the current prognostication system in CLL. In therapy, the field of CLL has seen major changes from oral chlorambucil and steroids prior to 1980s, to chemo-immunotherapy (CIT) with fludarabine, cyclophosphamide, rituximab (FCR) to the orally administered targeted therapeutic agents inhibiting kinases in the B cell receptor (BCR) signaling pathway such as Ibrutinib (BTK inhibitor) and Idelalisib (p110 PI3Kδ inhibitor) and novel anti-CD20 mAb's (monoclonal antibodies) such as obinutuzumab. This progress is continuing and other targeted therapeutics such as Bcl2 antagonists (Venetoclax or ABT-199) and finally chimeric antigen receptor against T cells (CART) are in the process of being developed. This review is an attempt to summarize the major benchmarks in the prognostication and in the therapy of CLL. The topic allocated to us by Dr Ayalew Tefferi and Dr Carlo Brugnara is very appropriate to reminisce what our understanding of chronic lymphocytic leukemia (CLL) was in 1976 and how rapidly have the advances occurring in this field affected the patients with CLL.

β2 -microglobulin normalization within 6 months of ibrutinib-based treatment is associated with superior progression-free survival in patients with chronic lymphocytic leukemia

BACKGROUND

A high pretreatment β2 -microglobulin (B2M) level is associated with inferior survival outcomes in patients with chronic lymphocytic leukemia. However, to the authors' knowledge, the prognostic and predictive significance of changes in B2M during treatment have not been reported to date.

METHODS

The authors analyzed 83 patients treated with ibrutinib-based regimens (66 with recurrent/refractory disease) and 198 treatment-naive patients who were treated with combined fludarabine, cyclophosphamide, and rituximab (FCR) to characterize changes in B2M and their relationship with clinical outcomes.

RESULTS

B2M rapidly decreased during treatment with ibrutinib; on multivariable analysis, patients who received FCR (odds ratio, 0.40; 95% confidence interval [95% CI], 0.18-0.90 [P = .027]) were less likely to have normalized B2M at 6 months than patients treated with ibrutinib. On univariable analysis, normalization of B2M was associated with superior progression-free survival (PFS) from the 6-month landmark in patients treated with ibrutinib-based regimens and FCR. On multivariable analysis, failure to achieve normalized B2M at 6 months of treatment was associated with inferior PFS (hazard ratio, 16.9; 95% CI, 1.3-220.0 [P = .031]) for patients treated with ibrutinib, after adjusting for the effects of baseline B2M, stage of disease, fludarabine-refractory disease, and del(17p). In contrast, in patients treated with FCR, negative minimal residual disease status in the bone marrow was the only variable found to be significantly associated with superior PFS (hazard ratio, 0.28; 95% CI, 0.12-0.67 [P = .004]).

CONCLUSIONS

Normalization of B2M at 6 months in patients treated with ibrutinib was found to be a useful predictor of subsequent PFS and may assist in clinical decision-making.

Long-term remissions after FCR chemoimmunotherapy in previously untreated patients with CLL: updated results of the CLL8 trial

Despite promising results with targeted drugs, chemoimmunotherapy with fludarabine, cyclophosphamide (FC), and rituximab (R) remains the standard therapy for fit patients with untreated chronic lymphocytic leukemia (CLL). Herein, we present the long-term follow-up of the randomized CLL8 trial reporting safety and efficacy of FC and FCR treatment of 817 treatment-naïve patients with CLL. The primary end point was progression-free survival (PFS). With a median follow-up of 5.9 years, median PFS were 56.8 and 32.9 months for the FCR and FC group (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.50-0.69, P < .001). Median overall survival (OS) was not reached for the FCR group and was 86.0 months for the FC group (HR, 0.68; 95% CI, 0.54-0.89, P = .001). In patients with mutated IGHV (IGHV MUT), FCR improved PFS and OS compared with FC (PFS: HR, 0.47; 95% CI, 0.33-0.68, P < .001; OS: HR, 0.62; 95% CI, 0.34-1.11, P = .1). This improvement remained applicable for all cytogenetic subgroups other than del(17p). Long-term safety analyses showed that FCR had a higher rate of prolonged neutropenia during the first year after treatment (16.6% vs 8.8%; P = .007). Secondary malignancies including Richter's transformation occurred in 13.1% in the FCR group and in 17.4% in the FC group (P = .1). First-line chemoimmunotherapy with FCR induces long-term remissions and highly relevant improvement in OS in specific genetic subgroups of fit patients with CLL, in particular those with IGHV MUT. This trial was registered at www.clinicaltrials.gov as #NCT00281918.

Monoclonal B-cell lymphocytosis and early-stage chronic lymphocytic leukemia: diagnosis, natural history, and risk stratification

Monoclonal B lymphocytosis (MBL) is defined as the presence of a clonal B-cell population in the peripheral blood with fewer than 5 × 10(9)/L B-cells and no other signs of a lymphoproliferative disorder. The majority of cases of MBL have the immunophenotype of chronic lymphocytic leukemia (CLL). MBL can be categorized as either low count or high count based on whether the B-cell count is above or below 0.5 × 10(9)/L. Low-count MBL can be detected in ∼5% of adults over the age of 40 years when assessed using standard-sensitivity flow cytometry assays. A number of biological and genetic characteristics distinguish low-count from high-count MBL. Whereas low-count MBL rarely progresses to CLL, high-count MBL progresses to CLL requiring therapy at a rate of 1% to 2% per year. High-count MBL is distinguished from Rai 0 CLL based on whether the B-cell count is above or below 5 × 10(9)/L. Although individuals with both high-count MBL and CLL Rai stage 0 are at increased risk of infections and second cancers, the risk of progression requiring treatment and the potential to shorten life expectancy are greater for CLL. This review highlights challenging questions regarding the classification, risk stratification, management, and supportive care of patients with MBL and CLL.

CD49d and CD26 are independent prognostic markers for disease progression in patients with chronic lymphocytic leukemia

CLL is characterized by extremely variable clinical course. Several prognostic factors can predict disease progression and therapeutic outcomes in those patients. The aim was to evaluate the use of CD49d and CD26 as independent prognostic markers in CLL patients. The present study measured surface expression of CD49d and CD26 by three-color flow cytometry in a series of 103 untreated CLL patients. We evaluated the prognostic role of CD49d and CD26 to predict the risk of lymphocyte doubling, disease progression and overall survival. We confirmed that CD49d and CD26 were significant predictors of lymphocyte doubling(P<0.001 for both markers) and disease progression (P<0.001 for both markers) but insignificant for overall survival(P=0.303 and 0.519 respectively. Multivariate analysis between clinical parameters and flow cytometry markers revealed that CD49d and CD26 are independent prognostic markers for lymphocyte doubling (HR=1.487 P=007 and HR=2.248, P=0.014 respectively) and progression to a more advanced stage (HR=3.191, P=0.049 and HR=7.887, P=0.003). Also, concordant expression of both markers was found to improve their predictive power. Many studies reported that CD49d and CD26 combined analysis was found to improve their power to predict the risk of lymphocyte doubling and disease progression. CD49d and CD26 have independent prognostic value and we suggest its use as a part of routine panel for prognostic stratification of CLL.

[Chronic lymphocytic leukemia : treatment concepts in transition]

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western hemisphere and mainly affects elderly patients. No curative treatment is currently available for this disease.

TREATMENT

Advanced disease is treated according to the patients' fitness and comorbidity burden as well as according the presence of high risk genetic factors in CLL cells. The detection of del(17p) and/or TP53 gene mutations reflects a very unfavorable prognosis and refractoriness to chemotherapy (very high risk CLL). In physically fit patients without high comorbidity burden and without very high risk prognostic factors, chemoimmunotherapy containing fludarabine, cyclophosphamide, and the CD20 antibody rituximab (FCR) is standard therapy because this regimen has been shown to improve overall survival. In patients with significant comorbidity burden, a less intense chemoimmunotherapy regimen should be administered consisting of the alkylating agent chlorambucil plus CD20 antibody. In very high risk patients, kinase inhibitors blocking the signaling transduction pathway of the B cell receptor have been approved since 2014. The same substances are also approved in relapsed CLL. However, in relapsed CLL repetitive administration of chemoimmunotherapy is still an alternative treatment option, especially if the first remission was longer lasting (> 24 months). Allogeneic hematopoietic stem cell transplantation in very high risk CLL or early relapsed disease has become less important than in the past. In some patients considering the risk of the transplantation versus the risk of failing to respond to the new treatment option, this procedure might still be the treatment of choice in order to achieve long-lasting remissions.

CONCLUSION

In the choice of treatment for patients with CLL, several factors must be considered. Because of the broad spectrum of treatment options, therapy within a clinical study is still the best treatment option.

Prospective study of prognostic factors in asymptomatic patients with B-cell chronic lymphocytic leukemia-like lymphocytosis: the cut-off of 11 × 10(9)/L monoclonal lymphocytes better identifies subgroups with different outcomes

The arbitrary threshold of 5 × 10(9)/L chronic lymphocytic leukemia (CLL)-like lymphocytes differentiates monoclonal B lymphocytosis (MBL) from CLL. There are no prospective studies that search for the optimal cut-off of monoclonal lymphocytes able to predict outcome and simultaneously analyze the prognostic value of classic, immunophenotypic, and cytogenetic variables in patients with asymptomatic clonal CLL lymphocytosis (ACL), which includes MBL plus Rai 0 CLL patients. From 2003 to 2010, 231 ACL patients were enrolled in this study. Patients with 11q deletion and atypical lymphocyte morphology at diagnosis had shorter progression-free survival (PFS) (p = 0.007 and p = 0.015, respectively) and treatment-free survival (TFS) (p = 0.009 and p = 0.017, respectively). Elevated beta-2 microglobulin (B2M) also correlated with worse TFS (p = 0.002). The optimal threshold of monoclonal lymphocytes independently correlated with survival was 11 × 10(9)/L (p = 0.000 for PFS and p = 0.016 for TFS). As conclusion, monoclonal lymphocytosis higher than 11 × 10(9)/L better identifies two subgroups of patients with different outcomes than the standard cut-off value of 5 × 10(9)/L. Atypical lymphocyte morphology, 11q deletion and elevated B2M had a negative impact on the survival in ACL patients.

A new prognostic score for CLL

In this issue of Blood, Pflug et al describe the new prognostic score published by the German Chronic Lymphocytic Leukemia Study Group (GCLLSG).

Development of a comprehensive prognostic index for patients with chronic lymphocytic leukemia

In addition to clinical staging, a number of biomarkers predicting overall survival (OS) have been identified in chronic lymphocytic leukemia (CLL). The multiplicity of markers, limited information on their independent prognostic value, and a lack of understanding of how to interpret discordant markers are major barriers to use in routine clinical practice. We therefore performed an analysis of 23 prognostic markers based on prospectively collected data from 1948 CLL patients participating in phase 3 trials of the German CLL Study Group to develop a comprehensive prognostic index. A multivariable Cox regression model identified 8 independent predictors of OS: sex, age, ECOG status, del(17p), del(11q), IGHV mutation status, serum β2-microglobulin, and serum thymidine kinase. Using a weighted grading system, a prognostic index was derived that separated 4 risk categories with 5-year OS ranging from 18.7% to 95.2% and having a C-statistic of 0.75. The index stratified OS within all analyzed subgroups, including all Rai/Binet stages. The validity of the index was externally confirmed in a series of 676 newly diagnosed CLL patients from Mayo Clinic. Using this multistep process including external validation, we developed a comprehensive prognostic index with high discriminatory power and prognostic significance on the individual patient level. The studies were registered as follows: CLL1 trial (NCT00262782, http://clinicaltrials.gov), CLL4 trial (ISRCTN 75653261, http://www.controlled-trials.com), and CLL8 trial (NCT00281918, http://clinicaltrials.gov).

Prognostic factors in chronic lymphocytic leukemia: a conceptual approach

SUMMARY 

Prognostic assessment is an essential component in the management of patients with chronic lymphocytic leukemia. Prognostic factors (e.g., clinical stage, lymphocyte doubling time and IGHV mutational status/ZAP70 expression), allow predicting time to disease progression and need of therapy and also provide a rough estimate of the overall survival. The most important predictor of survival in patients requiring intervention is response to therapy and its degree, patients with undetectable minimal residual disease following therapy having a much better outcome than those with an inferior response. Given the increasing number of treatment modalities for CLL, the identification of predictive factors is important. Unfortunately, with the only exception of del(17p)/TP53 mutations that predict a poor response to purine analogs-based therapy and del(11q) that correlates with inferior response to fludarabine given as single agent, there are not reliable predictors of response. Well-conducted studies aimed at identifying prognostic and, particularly, predictive factors are needed. New prognostic and predictive parameters should demonstrate superiority over already well validated markers and be helpful in the management of patients with CLL.

miR-29c down-regulation is associated with disease aggressiveness and poor survival in Chinese patients with chronic lymphocytic leukemia

Aberrant expression of microRNAs in chronic lymphocytic leukemia (CLL) has been reported to be associated with clinical outcome and improve prognostic stratification. The aim of this study was to explore the association of miR-29c expression with clinical parameters and survival in 53 Chinese patients with CLL. We showed that the miR-29c expression level decreased significantly from early to advanced clinical stages, and was significantly lower in patients with β(2)-microglobulin higher than 3.5 mg/L or with disease progression or death. With the cut-off determined by receiver operating characteristic (ROC) curve analysis, optimizing concordance with immunoglobulin heavy chain (IgVH) mutation status, miR-29c negative and positive groups were defined as including 17 and 36 patients, respectively. The miR-29c negative group had a higher percentage of patients with trisomy 12 or deletion of 11q or 17p (70.6% vs. 34.3%; p = 0.014) compared to the miR-29c positive group. The median progression-free survival and overall survival of the miR-29c negative group were 21 and 92 months, respectively, significantly shorter than in the miR-29c positive group (both not reached; p = 0.002 and p = 0.042, respectively), and miR-29c down-regulation was an independent prognostic factor for PFS. In conclusion, down-regulation of miR-29c is associated with higher tumor burden and significantly predicts short survival in Chinese patients with CLL.

The changing paradigm of chronic lymphocytic leukemia management

B cell-chronic lymphocytic leukemia (CLL), the commonest adult leukemia in western world, is today most often diagnosed at early-stage, following the accidental detection of lymphocytosis during a routine blood analysis. Moreover, the expectations of CLL patients have dramatically changed in the past decade and for the first time a significant overall survival improvement has been demonstrated in the disease--at least in the younger and fit patients--with the use of the FCR regimen, which combines rituximab fludarabine and cyclophosphamide. New drugs and new regimens are currently being developed for the relapsed patients and for those too old or too frail to receive aggressive treatments. Some of these promising compounds will likely be part of the future front-line treatments. Additionally, the increasing knowledge on the molecular features that predict the clinical outcome may soon result in a molecular classification of the disease. These acquisitions are producing a migration from palliative care to a curative and individually-tailored approach. In this review we tried to summarize the advances achieved in the past decade and help the specialists in internal medicine and the general practitioners to understand the completely changed scenario in which the disease should nowadays be managed.