Realizing precision medicine in chronic lymphocytic leukemia: Remaining challenges and potential opportunities.

Patients with chronic lymphocytic leukemia (CLL) exhibit diverse clinical outcomes. An expanding array of genetic tests is now employed to facilitate the identification of patients with high-risk disease and inform treatment decisions. These tests encompass molecular cytogenetic analysis, focusing on recurrent chromosomal alterations, particularly del(17p). Additionally, sequencing is utilized to identify TP53 mutations and to determine the somatic hypermutation status of the immunoglobulin heavy variable gene. Concurrently, a swift advancement of targeted treatment has led to the implementation of novel strategies for patients with CLL, including kinase and BCL2 inhibitors. This review explores both current and emerging diagnostic tests aimed at identifying high-risk patients who should benefit from targeted therapies. We outline existing treatment paradigms, emphasizing the importance of matching the right treatment to the right patient beyond genetic stratification, considering the crucial balance between safety and efficacy. We also take into consideration the practical and logistical issues when choosing a management strategy for each individual patient. Furthermore, we delve into the mechanisms underlying therapy resistance and stress the relevance of monitoring measurable residual disease to guide treatment decisions. Finally, we underscore the necessity of aggregating real-world data, adopting a global perspective, and ensuring patient engagement. Taken together, we argue that precision medicine is not the mere application of precision diagnostics and accessibility of precision therapies in CLL but encompasses various aspects of the patient journey (e.g., lifestyle exposures and comorbidities) and their preferences toward achieving true personalized medicine for patients with CLL.

IκBε deficiency accelerates disease development in chronic lymphocytic leukemia.

The NFKBIE gene, which encodes the NF-κB inhibitor IκBε, is mutated in 3-7% of patients with chronic lymphocytic leukemia (CLL). The most recurrent alteration is a 4-bp frameshift deletion associated with NF-κB activation in leukemic B cells and poor clinical outcome. To study the functional consequences of NFKBIE gene inactivation, both in vitro and in vivo, we engineered CLL B cells and CLL-prone mice to stably down-regulate NFKBIE expression and investigated its role in controlling NF-κB activity and disease expansion. We found that IκBε loss leads to NF-κB pathway activation and promotes both migration and proliferation of CLL cells in a dose-dependent manner. Importantly, NFKBIE inactivation was sufficient to induce a more rapid expansion of the CLL clone in lymphoid organs and contributed to the development of an aggressive disease with a shortened survival in both xenografts and genetically modified mice. IκBε deficiency was associated with an alteration of the MAPK pathway, also confirmed by RNA-sequencing in NFKBIE-mutated patient samples, and resistance to the BTK inhibitor ibrutinib. In summary, our work underscores the multimodal relevance of the NF-κB pathway in CLL and paves the way to translate these findings into novel therapeutic options.

Real-World Outcome of Treatment with Single-Agent Ibrutinib in Italian Patients with Chronic Lymphocytic Leukemia: Final Results of the EVIdeNCE Study.

Real-world data in clinical practice are needed to confirm the efficacy and safety that ibrutinib has demonstrated in clinical trials of patients with chronic lymphocytic leukemia (CLL). We described the real-world persistence rate, patterns of use, and clinical outcomes in 309 patients with CLL receiving single-agent ibrutinib in first line (1L, n = 118), 2L (n = 127) and ≥3L (n = 64) in the prospective, real-world, Italian EVIdeNCE study. After a median follow-up of 23.9 months, 29.8% of patients discontinued ibrutinib (1L: 24.6%, 2L: 29.9%, ≥3L: 39.1%), mainly owing to adverse events (AEs)/toxicity (14.2%). The most common AEs leading to discontinuation were infections (1L, ≥3L) and cardiac events (2L). The 2-year retention rate was 70.2% in the whole cohort (1L: 75.4%, 2L: 70.1%, ≥3L: 60.9%). The 2-year PFS and OS were, respectively, 85.4% and 91.7% in 1L, 80.0% and 86.2% in 2L, and 70.1% and 80.0% in ≥3L. Cardiovascular conditions did not impact patients' clinical outcomes. The most common AEs were infections (30.7%), bleeding (12.9%), fatigue (10.0%), and neutropenia (9.7%), while grade 3-4 atrial fibrillation occurred in 3.9% of patients. No new safety signals were detected. These results strongly support ibrutinib as a valuable treatment option for CLL.

Disrupting pro-survival and inflammatory pathways with dimethyl fumarate sensitizes chronic lymphocytic leukemia to cell death.

Microenvironmental signals strongly influence chronic lymphocytic leukemia (CLL) cells through the activation of distinct membrane receptors, such as B-cell receptors, and inflammatory receptors, such as Toll-like receptors (TLRs). Inflammatory pathways downstream of these receptors lead to NF-κB activation, thus protecting leukemic cells from apoptosis. Dimethyl fumarate (DMF) is an anti-inflammatory and immunoregulatory drug used to treat patients with multiple sclerosis and psoriasis in which it blocks aberrant NF-κB pathways and impacts the NRF2 antioxidant circuit. Our in vitro analysis demonstrated that increasing concentrations of DMF reduce ATP levels and lead to the apoptosis of CLL cells, including cell lines, splenocytes from Eµ-TCL1-transgenic mice, and primary leukemic cells isolated from the peripheral blood of patients. DMF showed a synergistic effect in association with BTK inhibitors in CLL cells. DMF reduced glutathione levels and activated the NRF2 pathway; gene expression analysis suggested that DMF downregulated pathways related to NFKB and inflammation. In primary leukemic cells, DMF disrupted the TLR signaling pathways induced by CpG by reducing the mRNA expression of NFKBIZ, IL6, IL10 and TNFα. Our data suggest that DMF targets a vulnerability of CLL cells linked to their inflammatory pathways, without impacting healthy donor peripheral blood mononuclear cells.