Ibrutinib, a first-in-class Bruton’s Tyrosine Kinase inhibitor (BTKi), is a commonly deployed therapeutic option for previously untreated, and relapsed/refractory (R/R) patients with chronic lymphocytic leukemia (CLL). The use of ibrutinib is, however, partially limited by significant off-target side effects. Zanubrutinib (zanu) is a second-generation BTKi with enhanced target selectivity and occupancy of the kinase binding site. The SEQUOIA study showed that zanu significantly prolonged progression-free survival (PFS) when compared to bendamustine–rituximab (BR) in treatment-naive CLL patients with an acceptable safety profile. More recently, data from the phase III ALPINE trial which directly compared zanu with ibrutinib has demonstrated that zanu’s advantages are both an improved safety profile and enhanced clinical efficacy. Based on the results of the SEQUOIA and ALPINE pivotal trials the Food and Drug Administration (FDA) and European Medicines Agency (EMA) licensed zanu for the treatment of patients with CLL or small lymphocytic lymphoma (SLL) in January 2023. The updated (v2.2023) National Comprehensive Cancer Network (NCCN) guidelines and newly released German CLL algorithm, suggest that zanu may replace first-generation BTKi as one of the preferred therapeutic options for patients with CLL/SLL due to its increased selectivity for the kinase binding site, improved therapeutic efficacy, and favorable toxicity profile.

Keywords: chronic lymphocytic leukemia; older patient, Bruton tyrosine kinase, BCL2, cost-effectiveness Bruton tyrosine kinase inhibitors (BTKi) and the BCL2 inhibitor venetoclax, with or without the anti CD20 monoclonal antibody Obinutuzumab, represent the preferred options for the first-line therapy of CLL because they are more effective and may improve quality of life. However, pa-tient’s inclusion criteria were heterogeneous across trials designed for older patients and the identification of CLL-specific parameters identifying unfit patients at risk of developing drug-specific adverse events are required to guide treatment choice. Due to inclusion/exclusion criteria in trials, higher discontinuation rates with BTKi were reported in real-world studies and registry analyses provided useful information on factors predicting for earlier discontinuation in a real-world setting. Though targeted agents were shown to be cost-effective treatments in high-income countries, the out-of-pocket expenses may limit accessibility to these drugs and the overall expenditure for new drugs in CLL is projected to increase substantially posing an issue for sustainability. This being said, the choice of a finite duration treatment based on venetoclax containing regimens or treatment until progression with BTKi is today possible in high- income countries and the therapy choice drivers are represented by coexisting medical conditions rather than age, by patient expectations, logistics and sustainability.

(1) Background: Heart failure (HF) is the final stage of multiple cardiac diseases, which has now become a severe public health problem worldwide. β-Adrenergic receptor (β-AR) overactivation is a major pathological factor associated with multiple cardiac diseases and mediates cardiac fibrosis and inflammation. Previous study has demonstrated that Bruton's tyrosine kinase (BTK) mediated cardiac fibrosis by TGF-β related signal pathways, indicating that BTK was a potential drug target for cardiac fibrosis. Zanubrutinib, a second-generation BTK inhibitor, has shown anti-fibrosis effects in previous research. However, it is unclear whether Zanubrutinib can alleviate cardiac fibrosis induced by β-AR overactivation;(2) Methods: In vivo: Male C57BL/6J mice were treated with or without the β-AR agonist isoproterenol (ISO) to establish cardiac fibrosis animal model. Here, results showed that BTK inhibitor Zanubrutinib (ZB) had a great effect on cardiac fibrosis and inflammation induced by β-AR. In vitro: Results showed that ZB alleviated β-AR-induced cardiac fibroblast activation and macrophage proinflammatory cytokine production. Further mechanism studies demonstrated that ZB inhibited β-AR-induced cardiac fibrosis and inflammation by BTK、STAT3、NF-κB and PI3K/Akt signal pathways both in vivo and in vitro; (4) Conclusions: our research provides evidence that ZB ameliorates β-AR-induced cardiac fibrosis and inflammation.

The use of the Bruton’s tyrosine kinase (BTK) inhibitors has changed the management and clinical history of patients with chronic lymphocytic leukemia (CLL). BTK is a critical molecule that interconnects B-cell antigen receptor (BCR) signaling. BTKIs are classified into two categories: irreversible (covalent) inhibitors and reversible (non-covalent) inhibitors. Ibrutinib is the first irreversible BTK inhibitor approved by the U.S. Food and Drug Administration in 2013 as a breakthrough therapy in CLL patients. Subsequently, several studies evaluated the efficacy and safety of new agents with reduced toxicity when compared with ibrutinib. Two other irreversible, second-generation BTK inhibitors, acalabrutinib and zanubrutinib, were developed to reduce ibrutinib-mediated adverse effects. Additionally, new reversible BTK inhibitors are currently under development in an early phase studies to improve their activity and to diminish adverse effects. This review summarizes the pharmacology, clinical efficacy, safety, dosing, drug-drug interactions associated with the treatment of CLL with BTK inhibitors, and examines its further implications.