Safety and efficacy of zandelisib plus zanubrutinib in previously treated follicular and mantle cell lymphomas.

The combination of the phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor zandelisib with the Bruton's tyrosine kinase (BTK) inhibitor zanubrutinib was hypothesized to be synergistic and prevent resistance to single-agent therapy. This phase 1 study (NCT02914938) included a dose-finding stage in patients with relapsed/refractory (R/R) B-cell malignancies (n = 20) and disease-specific expansion cohorts in follicular lymphoma (FL; n = 31) or mantle cell lymphoma (MCL; n = 19). The recommended phase 2 dose was zandelisib 60 mg on Days 1-7 plus zanubrutinib 80 mg twice daily continuously in 28-day cycle. In the total population, the most common adverse events (AEs; all grades/grade 3-4) were neutropenia (35%/24%), diarrhoea (33%/2%), thrombocytopenia (32%/8%), anaemia (27%/8%), increased creatinine (25%/0%), contusion (21%/0%), fatigue (21%/2%), nausea (21%/2%) and increased aspartate aminotransferase (24%/6%). Three patients discontinued due to AEs. The overall response rate was 87% (complete response [CR] = 33%) for FL and 74% (CR = 47%) for MCL. The median duration of response and progression-free survival (PFS) were not reached in either group. The estimated 1-year PFS was 72.3% (95% confidence interval [CI], 51.9-85.1) for FL and 56.3% (95% CI, 28.9-76.7) for MCL (median follow-up: 16.5 and 10.9 months respectively). Zandelisib plus zanubrutinib was associated with high response rates and no increased toxicity compared to either agent alone.

Strategies for overcoming resistance to Bruton's tyrosine kinase inhibitor zanubrutinib.

Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the treatment of B-cell malignancies. They target BTK, a key effector in the B-cell receptor (BCR) signaling pathway, crucial for B-cell survival and proliferation. The first-in-class irreversible BTK inhibitor, ibrutinib, was approved for various B-cell malignancies but has limitations due to off-target effects. Second-generation inhibitors, such as acalabrutinib and zanubrutinib, offer improved selectivity and reduced side effects. However, resistance to BTK inhibitors, driven by BTK mutations, remains a challenge. Combinatorial therapies with PI3K inhibitors, immune checkpoint inhibitors, BH3 mimetics, and anti-CD20 antibodies show promise in overcoming resistance. Noncovalent BTK inhibitors and proteolysis-targeting chimeras (PROTACs) are emerging strategies with potential to combat resistance. Overall, advancements in BTK-targeted therapies provide hope for improved outcomes in patients with B-cell malignancies and a promising avenue to address drug resistance. Further research is needed to optimize combination therapies and identify optimal treatment regimens.

Identifying and addressing unmet clinical needs on the use of zanubrutinib in chronic lymphocytic leukemia: A consensus-based position paper from an ad hoc expert panel.

Zanubrutinib has been approved for treating patients with different lymphoproliferative disorders and now represents a significant breakthrough in treating relapsed/refractory and previously untreated patients with chronic lymphocytic leukemia (CLL). Because few systematic studies or comparative randomized clinical trials have been conducted, optimal use of zanubrutinib in approved indications may be challenging. This article presents the results of a group discussion among an ad hoc constituted panel of experts to identify and address unmet clinical needs (UCNs) in using zanubrutinib in patients with CLL. Key UCNs were selected according to the criterion of clinical relevance using the Delphi process. Panel members reviewed the results of first-line and upstream controlled trials in which the efficacy and toxicity profile of zanubrutinib and other BTK inhibitors were investigated in patients with CLL. Based on a critical discussion of data, the panel produced recommendations for using zanubrutinib and proposals for new studies to increase the evidence for the optimal treatment of patients with CLL. The recommendations given by the panel are intended for use not only by expert centers but, above all, by less experienced hematologists as well as general practitioners.

Zanubrutinib-lenalidomide-rituximab (ZR2) in unfit diffuse large B-cell lymphoma: efficient and tolerant.

The objective of this study is to examine the effectiveness and safety of zanubrutinib, rituximab, and lenalidomide (ZR2) in unfit patients with diffuse large B-cell lymphoma (DLBCL). Thrombosis or bleeding risk of ZR2 regimen, especially when antiplatelet agents were co-prescribed, was also evaluated. We retrospectively reviewed unfit newly diagnosed (ND) and refractory or relapsed (R/R) patients with DLBCL who were administered with ZR2 regimen in two medical centers between December 2019 and February 2022. Response rates, progression-free survival (PFS), overall survival (OS), bleeding adverse events (AEs), and thrombosis episodes were analyzed. Furthermore, we investigated the effects of zanubrutinib alone or in combination with lenalidomide on platelet functions in vitro and in vivo. A total of 30 unfit patients (13 ND DLBCL and 17 R/R DLBCL patients) who received ZR2 regimen were enrolled in the study (median age: 69.5 years). The ultimate ORRs for the ND DLBCL and R/R DLBCL were 77.0% and 50.1%, respectively. The median follow-up was 16.6 months. The median PFS and OS were not achieved during the follow-up time. Subcutaneous hemorrhage AEs occurred in four cases, three cases suffered severe bleeding events, and thrombosis events were observed in two patients. ZR2 regimen inhibited platelet functions (aggregation, clot retraction, spreading and activation) in vitro and in vivo function testing especially in response to collagen. ZR2 is an efficient treatment option for unfit patients with DLBCL and could be well tolerated. Notably, this regimen inhibited platelet functions. Antiplatelet agents should be used with caution in patients treated with this regimen.

Improved efficacy and safety of zanubrutinib versus ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL) in China: a subgroup of ALPINE.

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has different epidemiology in Chinese vs. Western patients, but there are few studies of CLL/SLL in large populations of Chinese patients. ALPINE is a global phase 3 trial investigating Bruton tyrosine kinase inhibitors zanubrutinib vs. ibrutinib to treat relapsed/refractory (R/R) CLL/SLL. Here we report results from the subgroup of Chinese patients. Adults with R/R CLL/SLL were randomized 1:1 to receive zanubrutinib (160 mg twice-daily) or ibrutinib (420 mg once-daily) until disease progression or unacceptable toxicity. Endpoints included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety. Data were analyzed descriptively. Ninety patients were randomized in China (zanubrutinib, n = 47; ibrutinib, n = 43). Baseline characteristics were balanced between groups, with fewer male patients in the zanubrutinib vs. ibrutinib group (55.3% vs. 69.8%). Median age was 60.5 years, 11% had del(17p) mutation, and 32% had tumor protein 53 (TP53) mutation. With median 25.3 months follow-up, ORR was 80.9% with zanubrutinib vs. 72.1% with ibrutinib. PFS was improved with zanubrutinib vs. ibrutinib (HR = 0.34 [95% CI, 0.15, 0.77]), and the HR for OS was 0.45 (95% CI, 0.14, 1.50). Rates of Grade ≥ 3 treatment-emergent adverse events (TEAEs; 64.4% vs. 72.1%), AEs leading to discontinuation (6.4% vs. 14.0%), and serious TEAEs (35.6% vs. 51.2%) were lower with zanubrutinib vs. ibrutinib. Zanubrutinib demonstrated improved ORR, PFS, and OS vs. ibrutinib and a more favorable safety profile in patients with R/R CLL/SLL in China. These results are consistent with the full global population of ALPINE. ClinicalTrials.gov: NCT03734016, registered November 7, 2018.

Cardiovascular events of Bruton's tyrosine kinase inhibitors: A real-world study based on the United States Food and Drug Administration Adverse Event Reporting System database.

AIMS: Bruton's tyrosine kinase inhibitors (BTKIs), including first-generation ibrutinib, second-generation acalabrutinib and zanubrutinib, may be involved in the mechanisms of action related to adverse events (AEs) of the cardiovascular system. We aimed to characterize the cardiovascular AEs of BTKIs reported in the US Food and Drug Administration (FDA) Adverse Event Reporting System, and to compare the cardiovascular risks of BTKIs. METHODS: Across all indications of three FDA-approved BTKIs, primary suspect drugs were extracted over two periods: from January 2013 to December 2022 (after the approval of the first BTKI), and from January 2020 to December 2022 (all three BTKIs on the market). Disproportionality was measured by reporting odds ratios (RORs) and information components. Additional analyses were performed without incorporating patients with underlying cardiovascular disease (CVD). RESULTS: A total of 10 353 cases included the uses of ibrutinib, acalabrutinib and zanubrutinib. Ibrutinib was significantly associated with 47 cardiovascular AEs. Acalabrutinib was associated with new signals, including cardiac failure (ROR = 1.82 [1.13-2.93]), pulmonary oedema (ROR = 2.15 [1.19-3.88]), ventricular extrasystoles (ROR = 5.18 [2.15-12.44]), heart rate irregular (ROR = 3.05 [1.53-6.11]), angina pectoris (ROR = 3.18 [1.71-5.91]) and cardiotoxicity (ROR = 25.22 [17.14-37.10]). In addition, cardiovascular events had an earlier onset in acalabrutinib users. Zanubrutinib was only associated with atrial fibrillation. Acalabrutinib and zanubrutinib had lower ROR values than ibrutinib. The AE signals were generally consistent between the population receiving and not receiving CVD medications. CONCLUSIONS: Potential cardiovascular risks identified in this study were not clearly noted on the label of marketed acalabrutinib. Caution should be paid to the cardiovascular risks of BTKIs having been or being developed.

Plain language summary of zanubrutinib or ibrutinib in chronic lymphocytic leukemia that is resistant to treatment or has come back after treatment.

WHAT IS THIS SUMMARY ABOUT?: This is a plain language summary of a research study called ALPINE. The study involved people who had been diagnosed with, and previously treated at least once for, relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). Lymphocytes help to find and fight off viruses and infections in the body, but when someone has CLL or SLL, the body creates abnormal lymphocytes, leaving the patient with a weakened immune system and susceptible to illness. In CLL, these lymphocytes are in the bone marrow and bloodstream, whereas for SLL, they are mostly found in the lymph nodes, such as those in the neck. HOW WAS THE RESEARCH DONE?: The ALPINE study was designed to directly compare the cancer-fighting effects and side effects of zanubrutinib and ibrutinib as treatment for patients with relapsed or refractory CLL/SLL. WHAT WERE THE RESULTS?: After 30 months, zanubrutinib was more effective than ibrutinib at reducing and keeping the cancer from coming back. Clinical Trial Registration: NCT03734016 (ClinicalTrials.gov).

Health-related quality of life in patients with Waldenström macroglobulinemia: results from the ASPEN trial.

Aim ASPEN is a randomized, open-label, Phase III study comparing zanubrutinib and ibrutinib in patients with Waldenström macroglobulinemia (WM). Materials & methods: Patient-reported outcomes were exploratory end points assessed using the EORTC QLQ-C30 and EQ-5D-5L VAS scores. Results: Overall, 201 patients (102 zanubrutinib; 99 ibrutinib) were enrolled. Clinically meaningful differences were observed in diarrhea and nausea/vomiting in both the intent-to-treat population and in patients attaining very good partial response (VGPR) in earlier cycles of treatment, as well as in long-term physical functioning and fatigue in patients achieving VGPR. Conclusion: Treatment with zanubrutinib was associated with greater improvements in health-related quality of life compared with ibrutinib in patients with WM and MYD88 mutations.Clinical Trial Registration: NCT03053440 (ClinicalTrials.gov).

Patient quality of life is importantWhat is this article about? This article talks about a study called the ASPEN trial, which compares two medicines used for treating a rare blood cancer that doctors call Waldenström macroglobulinemia. The medicines are called zanubrutinib (ZAN) and ibrutinib (IBR). They work in the same way, by blocking a protein called Bruton tyrosine kinase. When patients take medicines for an illness, it is important to learn about their physical, social, emotional and mental well-being (quality of life). In this study, we asked patients to fill out questionnaires about their well-being before starting the study treatment for their blood cancer, and again a few times while taking the medication, to see if there were any changes.What were the results of the study? There were two groups of patients. One group took ZAN and the other took IBR. The patients could not choose which medicine they were going to take. Results from both groups of patients were compared. Patients taking ZAN did not feel worse or better about their diarrhea and sickness, but those taking IBR said these symptoms had become worse. Both medicines improved how patients were feeling. However, improvement in tiredness and physical ability was larger in patients taking ZAN than those on IBR, especially for the patients whose cancer was getting better.What do the results mean? For patients with a rare blood cancer in this study, those taking ZAN had a better quality of life than those taking IBR.

Evaluation of second-generation Bruton's tyrosine kinase inhibitors for the treatment of mantle cell lymphoma.

INTRODUCTION: Second-generation Bruton's tyrosine kinase (BTK) inhibitors, acalabrutinib and zanubrutinib, are preferred agents for the treatment of relapsed and/or refractory mantle cell lymphoma (MCL) over first-generation BTK inhibitor, ibrutinib. The comparative safety and efficacy of these two agents have not been studied. Currently, the decision between using one second-generation BTK inhibitor over the other is largely dependent on provider preference, cost, organ dysfunction, presence of drug-drug interactions, adherence considerations, and theorized differences in safety outcomes due to the lack of head-to-head trials in MCL. METHODS: This retrospective, observational study seeks to provide real-world data on the safety and efficacy of second-generation BTK inhibitors in the setting of relapsed and/or refractory MCL. RESULTS: Thirty-eight patients treated with a second-generation BTK inhibitor were evaluated. Ten percent of patients experienced a select adverse drug event (ADE) in the acalabrutinib group that included hypertension and major hemorrhage with no patients experiencing a select ADE in the zanubrutinib group. CONCLUSIONS: Results support historical data that acalabrutinib and zanubrutinib have a more favorable safety profile compared to ibrutinib in MCL.

A Review of Resistance Mechanisms to Bruton's Kinase Inhibitors in Chronic Lymphocytic Leukemia.

Bruton's Tyrosine Kinase (BTK) inhibitors have become one of the most vital drugs in the therapy of chronic lymphocytic leukemia (CLL). Inactivation of BTK disrupts the B-cell antigen receptor (BCR) signaling pathway, which leads to the inhibition of the proliferation and survival of CLL cells. BTK inhibitors (BTKi) are established as leading drugs in the treatment of both treatment-naïve (TN) and relapsed or refractory (R/R) CLL. Furthermore, BTKi demonstrate outstanding efficacy in high-risk CLL, including patients with chromosome 17p deletion, TP53 mutations, and unmutated status of the immunoglobulin heavy-chain variable region (IGHV) gene. Ibrutinib is the first-in-class BTKi which has changed the treatment landscape of CLL. Over the last few years, novel, covalent (acalabrutinib, zanubrutinib), and non-covalent (pirtobrutinib) BTKi have been approved for the treatment of CLL. Unfortunately, continuous therapy with BTKi contributes to the acquisition of secondary resistance leading to clinical relapse. In recent years, it has been demonstrated that the predominant mechanisms of resistance to BTKi are mutations in BTK or phospholipase Cγ2 (PLCG2). Some differences in the mechanisms of resistance to covalent BTKi have been identified despite their similar mechanism of action. Moreover, novel mutations resulting in resistance to non-covalent BTKi have been recently suggested. This article summarizes the clinical efficacy and the latest data regarding resistance to all of the registered BTKi.

Bruton's Tyrosine Kinase Inhibitors: Recent Updates.

Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the landscape for the treatment of hematological malignancies, solid tumors, and, recently, autoimmune disorders. The BTK receptor is expressed in several hematopoietic cells such as macrophages, neutrophils, mast cells, and osteoclasts. Similarly, the BTK receptor is involved in signaling pathways such as chemokine receptor signaling, Toll-like receptor signaling, and Fc receptor signaling. Due to their unique mechanism, these agents provide a diverse utility in a variety of disease states not limited to the field of malignant hematology and are generally well-tolerated.

Bruton's tyrosine kinase-bearing B cells and microglia in neuromyelitis optica spectrum disorder.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease of the central nervous system that involves B-cell receptor signaling as well as astrocyte-microglia interaction, which both contribute to evolution of NMOSD lesions. MAIN BODY: Through transcriptomic and flow cytometry analyses, we found that Bruton's tyrosine kinase (BTK), a crucial protein of B-cell receptor was upregulated both in the blood and cerebrospinal fluid of NMOSD patients. Blockade of BTK with zanubrutinib, a highly specific BTK inhibitor, mitigated the activation and maturation of B cells and reduced production of causal aquaporin-4 (AQP4) autoantibodies. In a mouse model of NMO, we found that both BTK and pBTK expression were significantly increased in microglia. Transmission electron microscope scan demonstrated that BTK inhibitor ameliorated demyelination, edema, and axonal injury in NMO mice. In the same mice colocalization of GFAP and Iba-1 immunofluorescence indicated a noticeable increase of astrocytes-microglia interaction, which was alleviated by zanubrutinib. The smart-seq analysis demonstrated that treatment with BTK inhibitor instigated microglial transcriptome changes including downregulation of chemokine-related genes and genes involved in the top 5 biological processes related to cell adhesion and migration, which are likely responsible for the reduced crosstalk of microglia and astrocytes. CONCLUSIONS: Our results show that BTK activity is enhanced both in B cells and microglia and BTK inhibition contributes to the amelioration of NMOSD pathology. These data collectively reveal the mechanism of action of BTK inhibition and corroborate BTK as a viable therapeutic target.

Indirect comparisons of efficacy of zanubrutinib versus orelabrutinib in patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma or relapsed or refractory mantle cell lymphoma.

We conducted two indirect comparisons to estimate the efficacy of zanubrutinib versus orelabrutinib in Chinese patients with relapsed or refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) or R/R mantle cell lymphoma (MCL). An unanchored matching-adjusted indirect comparison (MAIC) was performed in R/R CLL/SLL patients. Individual patient data from zanubrutinib trial (BGB-3111-205) were adjusted to match the aggregated data from the orelabrutinib trial (ICP-CL-00103). A naïve comparison was performed in R/R MCL for the different response assessment methodology and efficacy analysis set between the zanubrutinib (BGB-3111-206) and orelabrutinib (ICP-CL-00102) trials. Efficacy outcomes included ORR and PFS. In R/R CLL/SLL patients, after matching, IRC-assessed ORR was comparable (86.6% vs. 92.5%; risk difference, -5.9% [95% CI: -15.8%-3.8%]); IRC-assessed PFS was similar with a favorable trend in zanubrutinib over orelabrutinib (HR, 0.74 [95% CI: 0.37-1.47]) and the 18-month PFS rate was numerically higher in zanubrutinib (82.9% vs. 78.7%). In R/R MCL patients, naïve comparison showed investigator-assessed ORR was similar (83.7% vs. 87.9%; risk difference, -4.2% [95% CI: -14.8%-6.0%]), and CR rate was significantly higher in zanubrutinib over orelabrutinib (77.9% vs. 42.9%; risk difference, 35.0% [95% CI: 14.5%, 53.7%]). Investigator-assessed PFS was similar with a favorable trend (HR, 0.77 [95% CI: 0.45-1.32]) in zanubrutinib over orelabrutinib and the 12-month PFS rate was numerically higher in zanubrutinib (77.5% vs. 70.8%). MAIC result showed zanubrutinib demonstrated favorable PFS over orelabrutinib for R/R CLL/SLL patients. The naïve comparison showed zanubrutinib had favorable PFS and higher CR rate than orelabrutinib for R/R MCL patients.

Anticancer effect of zanubrutinib in HER2-positive breast cancer cell lines.

Small molecule Bruton's tyrosine kinase (BTK) inhibitors have been developed for the treatment of various haemato-oncological diseases, and ibrutinib was approved as the first BTK inhibitor for anticancer therapy in 2013. Previous reports proved the receptor kinase human epidermal growth factor receptor 2 (HER2) to be a valid off-target kinase of ibrutinib and potentially other irreversible BTK inhibitors, as it possesses a druggable cysteine residue in the active site of the enzyme. These findings suggest ibrutinib as a candidate drug for repositioning in HER2-positive breast cancer (BCa). This subtype of breast cancer belongs to one of the most common classes of breast tumours, and its prognosis is characterized by a high rate of recurrence and tumour invasiveness. Based on their similar kinase selectivity profiles, we investigated the anticancer effect of zanubrutinib, evobrutinib, tirabrutinib and acalabrutinib in different BCa cell lines and sought to determine whether it is linked with targeting the epidermal growth factor receptor family (ERBB) pathway. We found that zanubrutinib is a potential inhibitor of the HER2 signalling pathway, displaying an antiproliferative effect in HER2-positive BCa cell lines. Zanubrutinib effectively inhibits the phosphorylation of proteins in the ERBB signalling cascade, including the downstream kinases Akt and ERK, which mediate key signals ensuring the survival and proliferation of cancer cells. We thus propose zanubrutinib as another suitable candidate for repurposing in HER2-amplified solid tumours.

Unmet clinical needs in the use of zanubrutinib in malignant lymphomas (Waldenström macroglobulinemia, marginal zone lymphoma and mantle cell lymphoma): A consensus-based position paper from an ad hoc expert panel.

Zanubrutinib has been approved for the treatment of patients with different lymphoproliferative disorders, and now represents a major breakthrough in the treatment of patients resistant or relapsing after the recommended therapies. Because few systematic studies or comparative randomized clinical trials have been conducted, optimal use of the drug in approved indications is challenging, and questions are emerging on its use in earlier stages of the disorders. This article presents the results of group discussion among an ad hoc constituted panel of experts aimed at identifying and addressing unmet clinical needs (UCNs) in the use of zanubrutinib in the lymphomas which have received the approval of use, specifically Waldenström macroglubulinemia, marginal zone lymphoma and mantle cell lymphoma. Key UCNs were selected according to the criterion of clinical relevance using the Delphi process. The panel produced recommendations and proposals for new studies for the management of the identified UCNs. These recommendations are intended for use not only by expert centers but above all by not experienced hematologists as well as general practitioners.

Sequencing and combination of current small-molecule inhibitors for chronic lymphocytic leukemia: Where is the evidence?

Small-molecule inhibitors have revolutionized the treatment of chronic lymphocytic leukemia (CLL), a landscape once dominated by chemoimmunotherapy (i.e., an anti-CD20 monoclonal antibody in combination with systemic chemotherapy) in fit and unfit individuals. Key challenges include the management of refractory disease as well as the optimization of the therapy sequence. Decreased responsiveness has been observed with prolonged treatment, especially with Bruton tyrosine kinase (BTK) and phosphatidylinositol 3-kinase (PI3K) inhibitors which are given continuously, while venetoclax, an agent that targets dysregulations in intrinsic apoptosis signaling, has a fixed duration when combined with anti-CD20 monoclonal antibodies or BTK inhibitors. Combination therapy aims to synergistically target different oncogenic signaling pathways to abrogate the proliferation of resistant clones and thereby allows for fixed-duration treatments. An advantage of fixed-duration therapy is the potential to decrease financial and drug-induced toxicities. Sequencing of therapies is important to individualize treatment decisions based on factors such as age, comorbidities, tolerability, and patient preferences. However, to date, there are limited data to guide the rational sequencing or combination of these therapies, since conventional chemoimmunotherapy or chemotherapy regimens were used as comparators against these small-molecule inhibitors in trials that led to their regulatory approvals. In this article, we examined and evaluated the current evidence for sequencing versus the combination of small-molecule inhibitors for CLL by conducting comprehensive searches of the United States National Library of Medicine PubMed database, key meeting abstracts, and clinical practice guidelines. We also summarized findings from expert opinions to elucidate best practices for clinical scenarios with limited evidence to guide treatment selection.

Next-Generation Sequencing-Optimal Sequencing of Therapies in Relapsed/Refractory Chronic Lymphocytic Leukemia (CLL).

PURPOSE OF REVIEW: This research paper aims to provide an overview of evidence-based sequencing of therapies in relapsed/refractory chronic lymphocytic leukemia (CLL) in the era of targeted drugs. RECENT FINDINGS: In the absence of data from randomized clinical trials comparing novel agents head-to-head, growing evidence suggests that patients with late relapse (> 2 years) after fixed-duration therapies benefit from identical retreatment, whereas a class switch is favorable in those with short-lived remissions or progressive disease on continuous drug intake. Treatment of patients previously exposed to both covalent inhibitors of BTK and BCL2 remains an unmet medical need. Novel drugs, in particular noncovalent BTKI, show promising efficacy in this difficult-to-treat subgroup in early clinical trials. The optimal sequencing of therapies in CLL requires consideration of individual patient factors and disease characteristics. Double-refractory disease continuous to pose a clinical challenge with a focus on participation in clinical trials whenever possible.

Cost-effectiveness of BTK inhibitors vs bendamustine and rituximab in chronic lymphocytic leukemia patients.

Background: We aimed to compare the cost-effectiveness of bruton tyrosine kinase inhibors (BTKis) versus bendamustine-rituximab (R-bendamustine) as a first-line treatment for Chinese patients with relapsed or refractory chronic lymphocytic leukemia. Methods: A partitioned survival model was constructed using TreeAge Pro 2022 software and transition probabilities were estimated from the reported survival probabilities using parametric survival modeling. One-way analysis and probabilistic sensitivity analysis were performed to explore the uncertainty of the modeling results. In addition, several scenario analyses were evaluated. Results: In comparison to R-bendamustine, zanubrutinib had an incremental cost-effectiveness ratio (ICER; life years) and ICER (quality-adjusted life years) of US$12,173.38 and $17,983.40, respectively. While ibrutinib had a higher ICER relative to R-bendamustine. Conclusion: Zanubrutinib was cost-effective for patients with relapsed or refractory chronic lymphocytic leukemia in China.

Ibrutinib and Bruton's Tyrosine Kinase Inhibitors in Chronic Lymphocytic Leukemia: Focus on Atrial Fibrillation and Ventricular Tachyarrhythmias/Sudden Cardiac Death.

BACKGROUND: The natural history of chronic lymphocytic leukemia (CLL) was dramatically improved by the introduction of ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor. In this review, we aimed to summarize and critically evaluate the association between first- and second-generation BTK inhibitors and the risk of atrial fibrillation (AF) and ventricular arrhythmias (VA). SUMMARY: Since the first clinical experience, the development of AF was observed as the result of off-target effects that likely combined with patient's predisposing risk factors and concomitant cardiac morbidities. More recently, both ibrutinib dose reduction and arrhythmia management allowed long-term treatment, with positive effects on progression-free survival and reduced all-cause mortality as well. Second-generation BTK inhibitors, acalabrutinib, and zanubrutinib have been tested and validated in CLL. A lower occurrence of AF as compared with ibrutinib has been found, although AF has always been a secondary endpoint of all studies that probed these agents. KEY MESSAGES: For this reason, caution should be exercised before concluding that second-generation BTK inhibitors are safer than ibrutinib. Recent data on the effectiveness of ibrutinib over a follow-up of 8 years show a remarkable benefit on all-cause mortality, which is of great value also for interpreting the clinical impact of the few cases of VA and sudden cardiac death (SCD) reported for ibrutinib, independently of QT lengthening. Since a risk of VA and SCD has been recently reported also during treatment with second-generation BTK inhibitors, it appears that this risk, usually reaching its maximum size effect at long-term follow-up, likely denotes a class effect of BTK inhibitors.

A rapid and sensitive UPLC-MS/MS method for the determination of zanubrutinib in beagle plasma and its application in pharmacokinetics.

A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of zanubrutinib in the plasma of beagle dogs. The column used was an Acquity BEH C18 column (2.1 mm × 50 mm, 1.7 µm), maintained at 40°C with an injection volume of 2 µl. The gradient elution program was as follows: 0-1 min, 10-10% A; 1-1.1 min, 10-90% A; 1.1-2.1 min, 90-90% A; 2.1-2.2 min, 90-10% A; 2.2-3.0 min, 10-10% A. Mobile phase A was 0.1% formic acid, B was acetonitrile, and the total analysis time was 3 min. The mass spectrometry was performed in positive ion mode, and the scanning mode was multi-reaction monitoring mode with electrospray ionization as the ion source; m/z 472.2 → 455.01 for zanubrutinib and m/z 441.03 → 137.99 for ibrutinib (internal standard). The plasma samples were processed by protein precipitation. The standard curve showed good linearity (r2 = 0.999 8) in the range of 1.0-1,000 ng/ml (zanubrutinib) with a low limit of quantification of 1 ng/ml. Also, the intra-day and inter-day precision (RSD) was <5.88% and the accuracy (RE) ranged from -1.56 to 1.08%; the recoveries of zanubrutinib in beagle plasma ranged from 90.12 to 93.53% (RSD 1.67-6.42%) and the ME values of zanubrutinib were 98.70-101.06% (RSD 5.37-8.49%, n = 6). All values meet US Food and Drug Administration requirements. A rapid, highly selective and sensitive method for the determination of zanubrutinib concentration in plasma by UPLC-MS/MS was successfully developed. This method is suitable for pharmacokinetic studies in beagle dogs by following oral administration of zanubrutinib.