Assessment of the 4-factor score: Retrospective analysis of 586 CLL patients receiving ibrutinib. A campus CLL study

Early reappearance of intraclonal proliferative subpopulations in ibrutinib-resistant chronic lymphocytic leukemia

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib represents an effective strategy for treatment of chronic lymphocytic leukemia (CLL), nevertheless about 30% of patients eventually undergo disease progression. Here we investigated by flow cytometry the long-term modulation of the CLL CXCR4dim/CD5bright proliferative fraction (PF), its correlation with therapeutic outcome and emergence of ibrutinib resistance. By longitudinal tracking, the PF, initially suppressed by ibrutinib, reappeared upon early disease progression, without association with lymphocyte count or serum beta-2-microglobulin. Somatic mutations of BTK/PLCG2, detected in 57% of progressing cases, were significantly enriched in PF with a 3-fold greater allele frequency than the non-PF fraction, suggesting a BTK/PLCG2-mutated reservoir resident within the proliferative compartments. PF increase was also present in BTK/PLCG2-unmutated cases at progression, indicating that PF evaluation could represent a marker of CLL progression under ibrutinib. Furthermore, we evidence different transcriptomic profiles of PF at progression in cases with or without BTK/PLCG2 mutations, suggestive of a reactivation of B-cell receptor signaling or the emergence of bypass signaling through MYC and/or Toll-Like-Receptor-9. Clinically, longitudinal monitoring of the CXCR4dim/CD5bright PF by flow cytometry may provide a simple tool helping to intercept CLL progression under ibrutinib therapy.

Chronic Lymphocytic Leukemia: Prognostic Factors in the Era of Novel Drugs

Novel drugs have profoundly changed the outcomes in chronic lymphocytic leukemia (CLL) patients, and the traditional prognostic factors that were identified in the era of chemoimmunotherapy need to be validated in the context of these new targeted therapies. Currently, the most important prognostic genetic biomarkers are the immunoglobulin heavy chain variable (IGHV) mutational status, genetic aberrations including del(17p)/TP53 abnormalities, and the complex karyotype. In this review, we discuss the prognostic role of these genomic markers in relation to novel treatments. Moreover, we present and discuss new scoring systems that were elaborated and validated in the era of new drugs. In routine clinical practice, the application of an extensive genomic work-up with validated prognostic markers could improve the identification of "very high-risk" CLL patients who could benefit from novel, more effective targeted treatments.

Prognostication in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in Western countries. CLL is a highly heterogeneous disease: some patients may never require therapy and others relapse several times after different therapeutic strategies. Therefore, in CLL, prognostic markers are essential to capture high-risk patients for different clinical endpoints including early treatment requirement, early progression after BTK or BCL2 inhibitors and Richter transformation. In early stage CLL, different biological and clinical biomarkers have been identified to predict time to treatment requirement that could be used to identify the most appropriate population for early intervention clinical trial. However, at the moment, the standard of care for early stage CLL remains watch & wait since no survival benefit has been identified in clinical trials with chemoimmunotherapy and with BTK inhibitors. In patients requiring treatment TP53 disruptions identify high-risk patients who benefit the most from long-term continuous therapy with BTKi. On the opposite side of the spectrum, IGHV mutated patients devoid of TP53 disruption benefit the most from fixed-duration therapy with venetoclax-obinutuzumab. In between, the highly heterogenous subgroup of patients with IGHV unmutated genes represents the group in which further efforts are needed to identify additional prognostic biomarkers aimed at selecting patients who can benefit from fixed-duration and patients who can benefit from long term BTKi therapy. In the context of the aggressive transformation of CLL, namely Richter syndrome, the clonal relationship to the CLL counterpart represents the strongest prognostic biomarker. Clonally related Richter syndrome still represents an unmet clinical need which requires further efforts to identify new therapeutic strategies.

Real-life diagnostic and therapeutic approach to CLL: a 2022 update from an expert panel in Tuscany

A panel of chronic lymphocytic leukemia (CLL) experts from Tuscany propose a real-life diagnostic and therapeutic approach CLL that considers the role of genomic and somatic prognostic factors in risk stratification and treatment decisions. Safety and efficacy of new agents has been demonstrated now not only in clinical trials but also in many real-world series. The BTK inhibitors, ibrutinib and acalabrutinib, and BH3 mimetic venetoclax are now indicated as first-line therapy and chemoimmunotherapy can be spared to the majority of CLL patients, thus preventing unnecessary hematological and non-hematological toxicity and second primary tumors. For treatment, FISH for 17 p and P53 mutational status are essential. IGHV mutation can be done at diagnosis or before treatment. Echography is the gold standard radiological investigation in CLL, at both diagnosis and response evaluation. Chemotherapy is virtually abandoned. Age, genetic risk, and patient comorbidities have to be carefully evaluated for treatment decision. With the availability of different drugs, there is a need for a uniform and shared approach in daily therapeutic choice. The proposed approach is based on current evidence and guidelines as well as results from clinical trials and daily clinical experience.

A perspective on prognostic models in chronic lymphocytic leukemia in the era of targeted agents

Despite the increase in the number of prognostic models currently available for evaluating patients with chronic lymphocytic leukemia (CLL), their current application and utilization in clinical practice in the era of targeted agents is unclear. A critical reappraisal of recently developed prognostic models is presented in this review. The underlying CLL's genetic instability and changes in the host's health and comorbidities can all contribute to the acquisition of additional risk factors for adverse outcomes during the course of the disease. Therefore, available risk models solely based on pretreatment variables only partially predict patients' clinical outcome. A dynamic prognostic model that takes into account changes in the risk profile over time could indeed be useful in routine clinical practice. The next generation of risk assessment models should incorporate post-treatment and response biomarkers such as minimal residual disease. Finally, recent advances in the field of machine learning present novel opportunities to generate models capable of providing an individualized estimation of clinical outcomes in CLL. However, in the era of improved prognostic models, it is important to remember that these indices should supplement but not replace clinical expertise and medical decision-making.