Managing toxicities of Bruton tyrosine kinase inhibitors

Design, Synthesis, and Biological Evaluation of Pyrrolo[1,2-a]quinoxalin-4(5H)-one Derivatives as Potent and Orally Available Noncovalent Bruton's Tyrosine Kinase (BTK) Inhibitors

Bruton's tyrosine kinase (BTK) is a therapeutic target for B-cell-driven malignancies. Most of the approved covalent BTK inhibitors are associated with treatment limitations due to off-target toxicity and drug resistance. Developing noncovalent BTK inhibitors is a promising strategy to address unmet clinical needs. Here, a novel series of pyrrolo[1,2-a]quinoxalin-4(5H)-one derivatives were designed and synthesized as noncovalent BTK inhibitors. Among them, representative compound 9 exhibited potent BTK inhibitory activity (IC50 = 21.6 nM) and excellent selectivity against a panel of 468 kinases. Moreover, the oral exposure property of compound 9 was improved, and the antitumor efficacy of compound 9 (TGI = 64.4%) was superior to the lead S2 (TGI = 28.7%) and Ibrutinib (TGI = 41.1%) in the U-937 xenograft models at an oral dosage of 50 mg/kg. All these results suggest that compound 9 is a potent, selective, and orally available noncovalent BTK inhibitor worthy of further development.

Comprehensive Characterization of Bruton's Tyrosine Kinase Inhibitor Specificity, Potency, and Biological Effects: Insights into Covalent and Noncovalent Mechanistic Signatures

Uncovering a drug's mechanism of action and possible adverse effects are critical components in drug discovery and development. Moreover, it provides evidence for why some drugs prove more effective than others and how to design better drugs altogether. Here, we demonstrate the utility of a high-throughput in vitro screening platform along with a comprehensive panel to aid in the characterization of 15 Bruton's tyrosine kinase (BTK) inhibitors that are either approved by the FDA or presently under clinical evaluation. To compare the potency of these drugs, we measured the binding affinity of each to wild-type BTK as well as a clinically relevant resistance mutant of BTK (BTK C481S). In doing so, we discovered a considerable difference in the selectivity and potency of these BTK inhibitors to the wild-type and mutant proteins. Some of this potentially contributes to the adverse effects experienced by patients undergoing therapy using these drugs. Overall, noncovalent BTK inhibitors showed stronger potency for both the wild-type and mutant BTK when compared with that of covalent inhibitors, with the majority demonstrating a higher specificity and less off-target modulation. Additionally, we compared biological outcomes for four of these inhibitors in human cell-based models. As expected, we found different phenotypic profiles for each inhibitor. However, the two noncovalent inhibitors had fewer off-target biological effects when compared with the two covalent inhibitors. This and similar in-depth preclinical characterization of drug candidates can provide critical insights into the efficacy and mechanism of action of a compound that may affect its safety in a clinical setting.

Disease-modifying strategies: Targeting protein kinases in multiple sclerosis and other autoimmune disorders

A wide variety of immunomodulatory therapies are already available for the treatment of multiple sclerosis (MS). Through fundamental insights from basic research with a gain of knowledge in the pathological processes underlying MS, the exploration of additional medical compounds within clinical trials has been ignited. Emerging novel medications with innovative mechanisms of action are being introduced. Those mechanisms of action include a broad therapeutic spectrum of substances targeting various protein kinases, some of which could also be used for the treatment of other autoimmune-mediated diseases. The advancement of new compounds could therefore enable a more personalized approach in treating MS, taking into consideration patients' co-existing autoimmune-mediated diseases. In this review, we discuss potential compounds targeting protein kinases, currently under investigation in clinical trials for various autoimmune diseases that could become viable treatment options for MS and comorbid autoimmune conditions in the future.

Treatment patterns, health care resource utilization, and costs of chimeric antigen receptor T-cell vs standard therapy for relapsed/refractory mantle cell lymphoma in the United States

BACKGROUND

Standard of care (SOC) for relapsed/refractory mantle cell lymphoma (R/R MCL) has included chemoimmunotherapy and targeted therapies (eg, Bruton tyrosine kinase inhibitors [BTKis]). The approval of novel chimeric antigen receptor T-cell (CAR T) therapy in 2020 expanded therapeutic options.

OBJECTIVE

To compare real-world patient characteristics, treatment patterns, health care resource utilization (HRU), and costs in traditional Medicare and commercially insured patients with R/R MCL treated with CAR T vs non-CAR T SOC (non-CAR T).

METHODS

Adult patients with R/R MCL who had received 2 or more lines of therapy (LOTs) and continuously enrolled in their health plan between July 1, 2016, and December 31, 2021 (Medicare), or June 30, 2023 (commercial), were stratified into non-CAR T and CAR T cohorts based on therapy received during the study period after MCL diagnosis. Index date was 2L initiation for the non-CAR T cohort and CAR T infusion date for the CAR T cohort. Outcomes included time to next treatment (TTNT), treatment-free interval, MCL-related HRU (inpatient days, emergency department visits, and outpatient visits), and costs (medical and pharmacy).

RESULTS

2,835 non-CAR T and 122 CAR T patients were included. Compared with non-CAR T patients, CAR T patients were more often commercially insured (27% vs 17.3%; P < 0.01), younger (median age 69 vs 74; P < 0.0001), and male (75.4% vs 64.4%; P = 0.012). Median follow-up after index was 209.5 (CAR T) and 413 (non-CAR T) days. More than one-third (36.9%) of non-CAR T patients received 3L or higher LOT after index and median TTNT decreased with LOT from 689 days (2L) to 184 days (6L). In contrast, only 15% of CAR T patients required additional LOT, and median TTNT post-CAR T was not reached. Duration of treatment-free interval similarly declined with LOT for non-CAR T patients, and the CAR T interval was significantly longer than all non-CAR T LOT. Use of targeted therapies in non-CAR T increased sequentially by LOT (2L: 76%; 6L: 93.2%; BTKi 2L: 26.8%; BTKi 6L: 34.1%). Following CAR T, 9% of patients received targeted therapy, predominantly lenalidomide based. All MCL-related HRU and medical and pharmacy costs were lower post-CAR T than post-index non-CAR T.

CONCLUSIONS

Non-CAR T was associated with a greater use of post-index LOT, which also had shorter TTNT and treatment-free intervals. This suggests frequent and earlier progression as patients cycle through non-CAR T therapies. Standardized costs were higher in post-index non-CAR T vs post-CAR T episode periods. This suggests that earlier adoption of CAR T may reduce cycling through increasingly more expensive and less effective non-CAR T LOTs, potentially reducing HRU and financial burdens on patients with R/R MCL and the health system.

BTKi-induced cardiovascular toxicity in CLL: Risk mitigation and management strategies

Targeted therapies, consisting of Bruton tyrosine kinase inhibitors (BTKis) or BCL-2 inhibitors, are the mainstay of contemporary treatments for chronic lymphocytic leukemia (CLL). The most common adverse effects (AEs) of BTKis are fatigue, bruising, infection, hematological and cardiovascular AEs. While AEs during treatment are usually mild (grades 1 and 2), grade 3 and 4 AEs have been detected in some patients, necessitating additional medical care and temporary or permanent drug discontinuation. In this review, we analyzed the cardiovascular effects associated with BTKi therapy for CLL and the essential practical aspects of multidisciplinary management of patients who develop cardiovascular toxicity during treatment. We particularly focus on the data and strategies for controlling cardiovascular risks associated with ibrutinib and newer BTKis (acalabrutinib, zanubrutinib and pirtobrutinib), including the development of atrial fibrillation, hypertension, ventricular arrhythmias, sudden death, heart failure, bleeding, and ischemic complications (stroke and myocardial infarction). This review highlights hematological insights underlying cardiotoxicity, an area that has received limited attention in comparison to the predominantly cardiological perspective. This review synthesizes emerging evidence on hematological biomarkers, cardiotoxic mechanisms, and therapeutic interventions, linking hematology and cardiology to enhance understanding and guide comprehensive prevention and management strategies.

Ibrutinib pharmacokinetics in B-lymphoproliferative disorders discloses exposure-related incidence of hypertension

OBJECTIVE

Ibrutinib has been the first Bruton tyrosine kinase inhibitor (BTKi) authorized for the treatment of B-cell lymphoproliferative disorders (B-LPDs). Numerous publications have confirmed the efficacy of this orally administrated drug in chemo-free regimens for B-LPDs. They also reported several adverse events (AE) associated with ibrutinib treatment. Whether these AEs depended on ibrutinib exposure has however been seldom explored.

METHODS

In the study reported here, the incidence of AE was recorded in 92 patients with B-LPD (mostly chronic lymphocytic leukemia n  = 79) for whom ibrutinib alone was proposed as fist line therapy. Moreover, a pharmacokinetics (PK) exploration was planned over one day after 1 month treatment. PK assays included drug and metabolite (DHD-ibrutinib) mean/median and maximal plasmatic concentrations as well as areas under the curve (AUE) data.

RESULTS

This PK evaluation was analyzed regarding AEs recorded over the first year of therapy, which were similar as in published reports. PK data disclosed a significant impact of ibrutinib exposure on infections but mostly on the occurrence of hypertension. The latter was mostly related to dihydrodiol-ibrutinib (DHD-ibrutinib) exposure.

CONCLUSIONS

These data suggest that a DHD-ibrutinib assay after one month of treatment could be interesting to consider a lower dosage for patients above maximal concentration thresholds for the drug, its metabolite or the sum of both. Whether this can be applied to newer BTKi remains to be explored but it could be important for patients to whom ibrutinib is proposed.

SOHO State of the Art Updates and Next Questions | Covalent Bruton's Tyrosine Kinase Inhibitors in Chronic Lymphocytic Leukemia

Inhibitors of Bruton's tyrosine kinase (BTK) are among the most widely used therapies for chronic lymphocytic leukemia (CLL) and established a new expectation for efficacy and safety in the treatment of this disease. Currently there are 3 covalent inhibitors of BTK approved for the treatment of CLL: ibrutinib, acalabrutinib, and zanubrutinib. The first-in-class covalent BTK inhibitor is ibrutinib, which as monotherapy has excellent efficacy in the front-line setting with a 7-year progression free survival (PFS) of 59%. Ibrutinib-based therapies have also demonstrated superiority over standard chemoimmunotherapy in the front-line and the relapsed/refractory setting. Acalabrutinib is a second-generation BTK inhibitor that has higher selectivity to BTK. Acalabrutinib has efficacy in both frontline and relapsed CLL and is associated with a decreased incidence of atrial fibrillation and hypertension when compared to ibrutinib. Like acalabrutinib, zanubrutinib was designed to be more selective for BTK than ibrutinib and to maximize BTK inhibition in tissues. Zanubrutinib has demonstrated clinical efficacy in first line and relapsed/refractory setting. These agents are indicated as monotherapy, with dosing until disease progression or intolerable toxicity, and are mainly differentiated by safety profile, although efficacy differences may exist as well. Combination with CD20 monoclonal antibodies and/or BCL2 inhibitors are alternative options for use. Here we will review efficacy and safety considerations with these agents.

DDI-GPT: Explainable Prediction of Drug-Drug Interactions using Large Language Models enhanced with Knowledge Graphs

Identifying potential drug-drug interactions (DDIs) before clinical use is essential for patient safety yet remains a significant challenge in drug development. We presented DDI-GPT, a deep learning framework that predicts DDIs by combining knowledge graphs (KGs) and pre-trained large language models (LLMs), enabling early detection of potential drug interactions. We demonstrated that DDI-GPT outperforms current state-of-the-art methods by capturing contextual dependencies between biomedical entities to infer potential DDIs. Through feature attribution methods, we show that our explainable deep learning (DL) models enhance the quality of explanations on the pathways and interactome networks. Using TwoSIDES as our benchmark dataset, DDI-GPT achieved the best performance of 0.964 in AUROC compared with existing DL methods. We also applied DDI-GPT to perform zero-shot prediction on 9,480 DDI records, encompassing 442 distinct drugs from the FDA Adverse Event Reporting System. DDI-GPT can attain a high accuracy of in 0.84 AUROC, with an improvement of 14% compared to the best previously published method. We explored model interpretations on predicted DDIs involving Bruton's tyrosine kinase (BTK) inhibitors and uncovered CYP3A-enriched signals underlying the contaminant use of BTK inhibitors with other drugs leading to toxicity. Altogether, DDI-GPT, implemented as both a web server platform and a software package, identifies DDI events and offers a deep learning tool for drug safety use with expandable features.

Bruton's tyrosine kinase: A promising target for treating systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disorder involving multiple organs and systems. There is growing evidence that autoreactive B cells occupy a central role in the occurrence and progression of SLE due to their ability to generate pathogenic autoantibodies. Small molecule inhibitors targeting Bruton's tyrosine kinase (BTK), a crucial intracellular kinase regulating B cell development and function, emerge as a new strategy to treat SLE in recent years and are superior to biologic agents depleting B cells in many aspects. Supportive data obtained from lupus-prone mice preliminarily demonstrated the promising therapeutic potential of BTK inhibition. However, these BTK inhibitors, including elsubrutinib, evobrutinib, etc., mostly face with unsatisfactory efficacy and certain safety issues during clinical use, driving the quest for new-generation inhibitors with improved potency and higher selectivity. This paper elaborates the importance of BTK involvement in SLE pathogenesis, reviews the clinical research progress of BTK inhibitors for SLE and discusses limitations and challenges the drugs met in development, in order to contribute to a deeper understanding of disease mechanism and provide a reference for new-generation BTK inhibitor research.

Novel Therapies for Primary Central Nervous System Lymphomas

PURPOSE OF REVIEW

Primary Central Nervous System Lymphoma (PCNSL) is an aggressive form of lymphoma that can involve the brain, spinal cord, leptomeninges and eyes. PCNSL prognosis continues to be poor, with 5-year survival rates of 30-40%. Therapeutic options are especially limited for relapsed/refractory (r/r) PCNSL. In recent years, studies shed light on the pathogenesis and oncogenic pathways driving PCNSL, leading to the development of novel therapeutics. In this review, we discuss the evidence supporting these novel agents and present ongoing clinical studies.

RECENT FINDINGS

Key oncogenic drivers of PCNSL include activation of the NFkB pathway, cell cycle dysregulation, somatic hypermutation and immune evasion, leading to the investigation of targeted therapeutics and immunotherapeutics to inhibit these pathways. Such approaches include BTK inhibitors, mTOR/PI3K inhibitors, immunomodulatory agents (IMIDs), immune checkpoint inhibitors and CD19-based CAR T-cells. The therapeutic repertoire for PCNSL is rapidly evolving, and a multi-modality approach including intensive chemotherapy regimens and novel therapies will likely be utilized in the future.

Real-world safety profile of zanubrutinib: a disproportionality analysis based on the FAERS database

OBJECTIVE

Zanubrutinib is a second-generation Bruton's tyrosine kinase inhibitor that has been approved for the treatment of several B cell malignancies. The aim of this study was to evaluate adverse events (AEs) associated with zanubrutinib based on the real-world data.

DESIGN

A disproportionality analysis was performed to identify the potential zanubrutinib-related AEs.

SETTING

The Food and Drug Administration AE Reporting System database from the fourth quarter of 2019 to the third quarter of 2023.

MAIN OUTCOME MEASURES

The results of the disproportionality analyses were presented as reported ORs (RORs). When the lower limit of the 95% CI for the ROR is greater than 1 and the number of AE reports is≥3, it indicates that the preferred term (PT) may be a positive AE signal.

RESULTS

A total of 846 AE reports with zanubrutinib as the primary suspect drug were obtained, with 2826 AEs. A total of 74 positive PT signals were detected across 18 system organ classes (SOCs). The most significant signal for SOC was 'blood and lymphatic system disorders' (ROR=2.8, 95% CI 2.3 to 3.3), while the most significant signal for PT was 'haemorrhage subcutaneous' (ROR=190.8, 95% CI 128.0 to 284.5). 13 unexpected off-label AEs were also observed, such as abnormal hair texture, skin discolouration, hypernatraemia, pericardial effusion and hypersomnia. The median time to onset of AEs associated with zanubrutinib was 51 days (IQR 13-192 days) and was consistent with the early failure model. In comparison with zanubrutinib monotherapy, the combination of zanubrutinib and rituximab therapy was linked to a higher risk of specific AEs, including myelosuppression, pneumonia, leucopenia, thrombocytopenia, abdominal pain, anaemia, pancytopenia and respiratory failure. Furthermore, the combination of zanubrutinib and chemotherapy increased the risk of several severe AEs, such as cardiac arrest, elevated blood lactate dehydrogenase levels and pancytopenia.

CONCLUSIONS

The results of the analysis provided valuable insights into the safety profile of zanubrutinib-treated patients, which was helpful for clinical monitoring and identifying potential AEs related to zanubrutinib.

Pirtobrutinib: A New and Distinctive Treatment Option for B-Cell Malignancies

OBJECTIVE

The objective was to evaluate the efficacy/safety of pirtobrutinib in the treatment of B-cell malignancies and distinguish it from other available Bruton's tyrosine kinase (BTK) inhibitors.

DATA SOURCES

A literature search of PubMed (January 2021 through November 2023) and Clinicaltrials.gov was conducted using terms pirtobrutinib, Jaypirca, and LOXO 305. Licensing trials of available BTK inhibitors were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language clinical trials were evaluated.

DATA SYNTHESIS

Pirtobrutinib was approved by the US Food and Drug Administration for the treatment of relapsed/refractory mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) based largely on a phase 1/2 study in B-cell malignancies. Pirtobrutinib demonstrated a 73% overall response rate (ORR) in the CLL population and 58% in MCL. Pirtobrutinib has activity in patients resistant to earlier-generation, covalent BTK inhibitors. In fact, the ORRs were similar in BTK-pretreated and naïve patients. Adverse effects include fatigue, diarrhea, bleeding, and infection. Atrial fibrillation, a class effect of BTK inhibitors, may be less common with pirtobrutinib.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING DRUGS

Compared with earlier-generation BTK inhibitors, pirtobrutinib is more selective for BTK and binds noncovalently to the receptor. Ongoing studies are evaluating pirtobrutinib's use in multiple B-cell malignancies and comparing it with other BTK inhibitors.

CONCLUSION

The characteristics of pirtobrutinib render it useful in the treatment of B-cell malignancies no longer responding to a previous BTK inhibitor, and results from ongoing clinical trials may support future expanded use.

BTK inhibitors: moving the needle on the treatment of chronic lymphocytic leukemia

INTRODUCTION

Bruton's tyrosine kinaseinhibitors (BTKis) changed the trajectory of upfront and relapsed/refractory chronic lymphocytic leukemia (CLL) treatment. However, BTKis are plagued by a spectrum of toxicities. Zanubrutinib was developed to circumvent challenges with prolonged tolerability by increasing BTK selectivity and maximizing efficacy through pharmacokinetic/pharmacodynamic optimization. However, with the availability of ibrutinib, acalabrutinib, and zanubrutinib, limited data exists to guide sequencing of BTKi therapy in the relapsed/refractory setting.

AREAS COVERED

We review the first head-to-head trial (ALPINE) of zanubrutinib versus ibrutinib for the treatment of relapsed/refractory CLL and compare zanubrutinib's clinical efficacy and toxicities, including in patients with del(17p) and/or TP53 mutations to ibrutinib and acalabrutinib.

EXPERT OPINION

Zanubrutinibrepresents one of the new standards of care for relapsed/refractory CLL based on superior progression-free survival and response rates over ibrutinib. Whilezanubrutinib is associated with fewer cardiac toxicities, similar rates of neutropenia and hypertension are noted. Ongoing studies are pushing the envelope, utilizing targeted drug combinations and minimal residual disease markers as well as receptor tyrosine kinase-like orphan receptor 1 inhibitors, chimeric antigen receptor T-cells, and novel BTK degraders. However, zanubrutinibrepresents a strong contender in the arsenal of treatment options for relapsed/refractory CLL.

Bruton tyrosine kinase inhibitor monotherapy in B-cell lymphoma and risk of infection: A systematic review and meta-analysis of randomized controlled trials

Bruton's tyrosine kinase (BTK) inhibitors are important therapeutic advances with promising efficacy outcomes in the treatment of patients with chronic lymphocytic leukemia and other B-cell lymphoma subtypes. However, the utility of BTK inhibitors can be limited by adverse events such as infections. In this systematic review and meta-analysis, we aim to determine the risk of various infections associated with BTK inhibitor monotherapy in B-cell lymphoma patients. A comprehensive search was conducted in MEDLINE/PubMed, Embase, and Web of Science databases from their inception until October 2023. ClinicalTrials.gov, bibliographies, and relevant conference abstracts were also searched for additional records. Randomized controlled trials that included any B-cell lymphoma patients treated with BTK inhibitor monotherapy and reported infection were included. Meta-analysis was performed to calculate risk ratio (RR) using a random-effects model in R Statistical Software, version 4.3.2. Of 3292 studies retrieved, we included 12 studies in this systematic review and meta-analysis. The median age of patients across the study arms ranged between 64 and 73 years. The overall pooled RR for any grade upper respiratory tract infections (URTI) associated with BTK inhibitor treatment was 1.55 (95% Confidence Interval (CI) 1.22-1.97). The RR of grade ≥3 URTI was reported in 14 out of 1046 patients, yielding an RR of 1.46 (95% CI 0.61-3.54), which was not statistically significant. The pooled RR of any grade pneumonia was 1.20 (95% CI 0.68-2.10) and grade ≥3 pneumonia was 1.12 (95% CI 0.67-1.85), both of which were not statistically significant. Patients with B-cell lymphoma who are undergoing BTK inhibitor monotherapy face an elevated risk of developing URTI. Clinicians prescribing BTK inhibitors should be aware of the potential infectious events that may occur. Close monitoring and the implementation of effective prophylactic measures are essential for managing these patients.

Targeting Bruton's tyrosine kinase (BTK) as a signaling pathway in immune-mediated diseases: from molecular mechanisms to leading treatments

Bruton's tyrosine kinase (BTK), a nonreceptor tyrosine kinase, plays a remarkable role in the transmission and amplification of extracellular signals to intracellular signaling pathways. Various types of cells use the BTK pathway to communicate, including hematopoietic cells particularly B cells and T cells. The BTK pathway plays a role in controlling the proliferation, survival, and functions of B cells as well as other myeloid cells. First, second, and third-generation BTK inhibitors are currently being evaluated for the treatment of immune-mediated diseases in addition to B cell malignancies. In this article, the available evidence on the action mechanisms of BTK inhibitors is reviewed. Then, the most recent data obtained from preclinical studies and ongoing clinical trials for the treatment of autoimmune diseases, such as pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, systemic lupus erythematosus, Sjögren's disease, rheumatoid arthritis, systemic sclerosis, multiple sclerosis, myasthenia gravis, and inflammatory diseases such as psoriasis, chronic spontaneous urticaria, atopic dermatitis, and asthma are discussed. In addition, adverse effects and complications associated with BTK inhibitors as well as factors predisposing patients to BTK inhibitors complications are discussed.

The potential of Bruton's tyrosine kinase (BTK) inhibitors in the pharmacotherapeutic management of immune and dermatological disease

INTRODUCTION

The review article explores the evolving role of Bruton's tyrosine kinase (BTK) inhibitors in immune-mediated dermatological conditions, addressing significant gaps in current treatment approaches.

AREAS COVERED

The review comprehensively discusses the mechanisms of action of BTK inhibitors, including irreversible and reversible inhibitors. Clinical applications of BTK inhibitors in dermatological diseases such as pemphigus, chronic spontaneous urticaria (CSU), hidradenitis suppurativa (HS), systemic lupus erythematosus (SLE), and atopic dermatitis are explored, highlighting recent advancements and ongoing clinical trials. Potential advantages of BTK inhibitors over existing therapies and challenges in translating preclinical findings to clinical outcomes are discussed.

EXPERT OPINION/COMMENTARY

BTK inhibitors represent a promising therapeutic avenue for immune-mediated dermatological conditions, offering oral administration, targeted pathway inhibition, and a favorable safety profile compared to biologic therapies. Ongoing research and clinical trials hold the potential to address unmet needs and reshape the therapeutic landscape in dermatology.

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.

Evidence-based expert consensus on clinical management of safety of Bruton's tyrosine kinase inhibitors (2024)

Bruton's tyrosine kinase inhibitors (BTKis) have revolutionized the treatment of B-cell lymphomas. However, safety issues related to the use of BTKis may hinder treatment continuity and further affect clinical efficacy. A comprehensive and systematic expert consensus from a pharmacological perspective is lacking for safety issues associated with BTKi treatment. A multidisciplinary consensus working group was established, comprising 35 members from the fields of hematology, cardiovascular disease, cardio-oncology, clinical pharmacy, and evidence-based medicine. This evidence-based expert consensus was formulated using an evidence-based approach and the Delphi method. The Joanna Briggs Institute Critical Appraisal (JBI) tool and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach were used to rate the quality of evidence and grade the strength of recommendations, respectively. This consensus provides practical recommendations for BTKis medication based on nine aspects within three domains, including the management of common adverse drug events such as bleeding, cardiovascular events, and hematological toxicity, as well as the management of drug-drug interactions and guidance for special populations. This multidisciplinary expert consensus could contribute to promoting a multi-dimensional, comprehensive and standardized management of BTKis.

Chronic Lymphocytic Leukemia: Management of Adverse Events in the Era of Targeted Agents

The treatment landscape for CLL has undergone a profound transformation with the advent of targeted agents (TAs) like Bruton's Tyrosine Kinase inhibitors (BTKis) and BCL-2 inhibitors (BCL-2is). These agents target crucial cellular pathways in CLL, offering superior efficacy over traditional chemo-immunotherapy, which has led to improved progression-free and overall survival rates. This advancement promises enhanced disease control and potentially normal life expectancy for many patients. However, the journey is not without challenges, as these TAs are associated with a range of adverse events (AEs) that can impact treatment efficacy and patient quality of life. This review focuses on detailing the various AEs related to TA management in CLL, evaluating their frequency and clinical impact. The aim is to present a comprehensive guide to the effective management of these AEs, ensuring optimal tolerability and efficacy of TAs. By reviewing the existing literature and consolidating findings, we provide insights into AE management, which is crucial for maximizing patient outcomes in CLL therapy.

Hypertension treatment for patients receiving ibrutinib: a multicenter retrospective study

ABSTRACT

Although Bruton tyrosine kinase inhibitors (BTKis) are generally well tolerated and less toxic than chemotherapy alternatives used to treat lymphoid malignancies, BTKis like ibrutinib have the potential to cause new or worsening hypertension (HTN). Little is known about the optimal treatment of BTKi-associated HTN. Randomly selected patients with lymphoid malignancies on a BTKi and antihypertensive drug(s) and with at least 3 months of follow-up data were sorted into 2 groups: those diagnosed with HTN before BTKi initiation (prior-HTN), and those diagnosed with HTN after BTKi initiation (de novo HTN). Generalized estimating equations assessed associations between time varying mean arterial pressures (MAPs) and individual anti-HTN drug categories. Of 196 patients included in the study, 118 had prior-HTN, and 78 developed de novo HTN. Statistically significant mean MAP reductions were observed in patients with prior-HTN who took β blockers (BBs) with hydrochlorothiazide (HCTZ), (-5.05 mmHg; 95% confidence interval [CI], 10.0 to -0.0596; P = .047), and patients diagnosed with de novo HTN who took either an angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) with HCTZ (-5.47 mmHg; 95% CI, 10.9 to -0.001; P = .05). These regimens also correlated with the greatest percentages of normotensive MAPs. Treatment of HTN in patients taking a BTKi is challenging and may require multiple antihypertensives. Patients with prior-HTN appear to benefit from combination regimens with BBs and HCTZ, whereas patients with de novo HTN appear to benefit from ACEi/ARBs with HCTZ. These results should be confirmed in prospective studies.

Ibrutinib topical delivery for melanoma treatment: The effect of nanostructured lipid carriers' composition on the controlled drug skin deposition

Melanoma is responsible for more than 80% of deaths related to skin diseases. Ibrutinib (IBR), a Bruton's tyrosine kinase inhibitor, has been proposed to treat this type of tumor. However, its low solubility, extensive first-pass effect, and severe adverse reactions with systemic administration affect therapeutic success. This study proposes developing and comparing the performance of two compositions of nanostructured lipid carriers (NLCs) to load IBR for the topical management of melanomas in their early stages. Initially, the effectiveness of IBR on melanoma proliferation was evaluated in vitro, and the results confirmed that the drug reduces the viability of human melanoma cells by inducing apoptosis at a dose that does not compromise dermal cells. Preformulation tests were then conducted to characterize the physical compatibility between the drug and the selected components used in NLCs preparation. Sequentially, two lipid compositions were used to develop the NLCs. Formulations were then characterized and subjected to in vitro release and permeation tests on porcine skin. The NLCs containing oleic acid effectively controlled IBR release over 24 h compared to the NLCs composed of pomegranate seed oil. Furthermore, the nanoparticles acted as permeation enhancers, increasing the fluidity of the lipids in the stratum corneum, as determined by EPR spectroscopy, which stimulated the IBR penetration more profoundly into the skin. However, the NLCs composition also influenced the permeation promotion factor. Thus, these findings emphasize the importance of the composition of NLCs in controlling and increasing the skin penetration of IBR and pave the way for future advances in melanoma therapy.

A review of Bruton's tyrosine kinase inhibitors in multiple sclerosis

Bruton's tyrosine kinase (BTK) inhibitors are an emerging class of therapeutics in multiple sclerosis (MS). BTK is expressed in B-cells and myeloid cells, key progenitors of which include dendritic cells, microglia and macrophages, integral effectors of MS pathogenesis, along with mast cells, establishing the relevance of BTK inhibitors to diverse autoimmune conditions. First-generation BTK inhibitors are currently utilized in the treatment of B-cell malignancies and show efficacy in B-cell modulation. B-cell depleting therapies have shown success as disease-modifying treatments (DMTs) in MS, highlighting the potential of BTK inhibitors for this indication; however, first-generation BTK inhibitors exhibit a challenging safety profile that is unsuitable for chronic use, as required for MS DMTs. A second generation of highly selective BTK inhibitors has shown efficacy in modulating MS-relevant mechanisms of pathogenesis in preclinical as well as clinical studies. Six of these BTK inhibitors are undergoing clinical development for MS, three of which are also under investigation for chronic spontaneous urticaria (CSU), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Phase II trials of selected BTK inhibitors for MS showed reductions in new gadolinium-enhancing lesions on magnetic resonance imaging scans; however, the safety profile is yet to be ascertained in chronic use. Understanding of the safety profile is developing by combining safety insights from the ongoing phase II and III trials of second-generation BTK inhibitors for MS, CSU, RA and SLE. This narrative review investigates the potential of BTK inhibitors as an MS DMT, the improved selectivity of second-generation inhibitors, comparative safety insights established thus far through clinical development programmes and proposed implications in female reproductive health and in long-term administration.

Integrated Safety Analysis of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, for the Treatment of Alopecia Areata from the ALLEGRO Clinical Trial Program

BACKGROUND

The ALLEGRO phase 2a and 2b/3 studies demonstrated that ritlecitinib, an oral JAK3/TEC family kinase inhibitor, is efficacious at doses of ≥ 30 mg in patients aged ≥ 12 years with alopecia areata (AA).

OBJECTIVE

The objective of this study was to evaluate the safety of ritlecitinib in an integrated analysis of four studies in AA.

METHODS

Two cohorts were analyzed: a placebo-controlled and an all-exposure cohort. Proportions and study size-adjusted incidence rates (IRs) of adverse events (AEs) of interest and laboratory abnormalities are reported.

RESULTS

In the placebo-controlled cohort (n = 881; median exposure: 169 days), the proportion of ritlecitinib-treated patients with AEs was 70.2-75.4% across doses versus 69.5% in the placebo group; serious AEs occurred in 0-3.2% versus 1.9% for the placebo. A total of 19 patients permanently discontinued due to AEs (5 while receiving the placebo). In the all-exposure cohort (n = 1294), median ritlecitinib exposure was 624 days [2091.7 total patient-years (PY)]. AEs were reported in 1094 patients (84.5%) and serious AEs in 57 (4.4%); 78 (6.0%) permanently discontinued due to AEs. The most common AEs were headache (17.7%; 11.9/100 PY), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive test (15.5%; 9.8/100 PY), and nasopharyngitis (12.4%; 8.2/100 PY). There were two deaths (breast cancer and acute respiratory failure/cardiorespiratory arrest). Proportions (IRs) were < 0.1% (0.05/100 PY) for opportunistic infections, 1.5% (0.9/100 PY) for herpes zoster, 0.5% (0.3/100 PY) for malignancies (excluding nonmelanoma skin cancer), and 0.2% (0.1/100 PY) for major adverse cardiovascular events.

CONCLUSIONS

Ritlecitinib is well tolerated with an acceptable safety profile up to 24 months in patients aged ≥ 12 years with AA (video abstract and graphical plain language summary available).

TRIAL REGISTRIES

ClinicalTrials.gov: NCT02974868 (date of registration: 11/29/2016), NCT04517864 (08/18/2020), NCT03732807 (11/07/2018), and NCT04006457 (07/05/2019).

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.

Unveiling the Cardiotoxicity Conundrum: Navigating the Seas of Tyrosine Kinase Inhibitor Therapies

Background: Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of various solid and hematologic malignancies by targeting dysregulated signaling pathways critical for malignant cell growth. However, these therapeutic benefits are often accompanied by cardiotoxicities, such as hypertension, left ventricular dysfunction, QT prolongation, and tachyarrhythmias, among others. These cardiotoxicities post a significant challenge in clinical management, often limiting the use of otherwise effective therapies. The underlying mechanism of TKI-induced cardiotoxicity appears to be multifaceted, involving several pathways including: direct cardiomyocyte damage, mitochondrial dysfunction, endothelial damage, and disruption of signaling pathways critical for cardiac function. The range and severity of cardiotoxicities vary significantly across different TKIs, necessitating a comprehensive understanding of each agent's specific cardiovascular risk profile. Preventing and managing TKI-induced cardiotoxicity requires a comprehensive, multidisciplinary approach. Early identification of at-risk patients through baseline cardiovascular risk assessments and appropriate monitoring during therapy is crucial. Strategies to mitigate cardiotoxic effects include dose modification, the use of cardioprotective agents, and temporary discontinuation of therapy. Additionally, decision making via multidisciplinary teams ensures minimization of cardiovascular complications while also continuing effective cancer treatment. Historically, data have been limited regarding cardiotoxicity and most cancer therapies, which certainly includes TKIs. This review aims to synthesize the current body of knowledge on TKI-associated cardiotoxicities, while highlighting the importance of vigilance and proactive management to minimize cardiovascular complications.

Invasive fungal infection incidence and risk factors in patients receiving ibrutinib in real-life settings: A nationwide population-based cohort study

BACKGROUND

Data on the risk of invasive fungal infections (IFI) with ibrutinib treatment are scarce.

OBJECTIVES

This study aimed to determine IFI incidence and risk factors in ibrutinib-treated patients in real-life settings.

METHODS

We constituted a cohort of ibrutinib incident users in the French National Healthcare Database. All patients ≥18 years with a first dispensing of ibrutinib between 21 November 2014 and 31 December 2019 were included. Patients were followed from the cohort entry date until IFI, ibrutinib discontinuation, death, or 31 December 2020, whichever came first. The cumulative incidence function method was used to estimate the probability of IFI accounting for competing risk of death. A multivariate cause-specific Cox proportional hazards model was used to assess independent IFI risk factors.

RESULTS

Among 6937 ibrutinib-treated patients, 1-year IFI cumulative incidence was 1.3%, with invasive aspergillosis being the most frequent. Allogenic or autologous stem cell transplantation (ASCT) (hazard ratio [HR] 3.59, 95% confidence interval [1.74; 7.41]), previous anticancer treatment (HR 2.12, CI 95% [1.34; 3.35]) and chronic respiratory disease (HR 1.66, [1.03; 2.67]) were associated with higher risk of IFI. Besides neutropenia and corticosteroids, use of anti-CD20 agents was significantly more frequent in patients having experienced IFI (HR 3.68, [1.82; 7.45]).

CONCLUSIONS

In addition to patients with ASCT history, severe neutropenia or treated with corticosteroids, our findings support active surveillance of IFIs in those with chronic respiratory disease, previously treated, or treated with anti-CD20 agents in combination with ibrutinib. Further studies are needed to optimise IFI prophylaxis in these patient subgroups.

Tislelizumab plus zanubrutinib for Richter transformation: the phase 2 RT1 trial

In patients with chronic lymphocytic leukemia, Richter transformation (RT) reflects the development of an aggressive lymphoma that is associated with poor response to chemotherapy and short survival. We initiated an international, investigator-initiated, prospective, open-label phase 2 study in which patients with RT received a combination of the PD-1 inhibitor tislelizumab plus the BTK inhibitor zanubrutinib for 12 cycles. Patients responding to treatment underwent maintenance treatment with both agents. The primary end point was overall response rate after six cycles. Of 59 enrolled patients, 48 patients received at least two cycles of treatment and comprised the analysis population according to the study protocol. The median observation time was 13.9 months, the median age was 67 (range 45-82) years. Ten patients (20.8%) had received previous RT-directed therapy. In total, 28 out of 48 patients responded to induction therapy with an overall response rate of 58.3% (95% confidence interval (CI) 43.2-72.4), including 9 (18.8%) complete reponse and 19 (39.6%) partial response, meeting the study's primary end point by rejecting the predefined null hypothesis of 40% (P = 0.008). Secondary end points included duration of response, progression-free survival and overall survival. The median duration of response was not reached, the median progression-free survival was 10.0 months (95% CI 3.8-16.3). Median overall survival was not reached with a 12-month overall survival rate of 74.7% (95% CI 58.4-91.0). The most common adverse events were infections (18.0%), gastrointestinal disorders (13.0%) and hematological toxicities (11.4%). These data suggest that combined checkpoint and BTK inhibition by tislelizumab plus zanubrutinib is an effective and well-tolerated treatment strategy for patients with RT. ClinicalTrials.gov Identifier: NCT04271956 .

Protein Kinases and their Inhibitors Implications in Modulating Disease Progression

Protein phosphorylation plays an important role in cellular pathways, including cell cycle regulation, metabolism, differentiation and survival. The protein kinase superfamily network consists of 518 members involved in intrinsic or extrinsic interaction processes. Protein kinases are divided into two categories based on their ability to phosphorylate tyrosine, serine, and threonine residues. The complexity of the system implies its vulnerability. Any changes in the pathways of protein kinases may be implicated in pathological processes. Therefore, they are regarded as having an important role in human diseases and represent prospective therapeutic targets. This article provides a review of the protein kinase inhibitors approved by the FDA. Finally, we summarize the mechanism of action of protein kinases, including their role in the development and progression of protein kinase-related roles in various pathological conditions and the future therapeutic potential of protein kinase inhibitors, along with links to protein kinase databases. Further clinical studies aimed at examining the sequence of protein kinase inhibitor availability would better utilize current protein kinase inhibitors in diseases. Additionally, this review may help researchers and biochemists find new potent and selective protein kinase inhibitors and provide more indications for using existing drugs.

Management of hypertension in patients with cancer: challenges and considerations

The survival rates of many cancers have significantly improved due to recent advancements in cancer screening and therapeutics. Although better cancer outcomes are encouraging, additional health challenges have surfaced, the utmost of which is the burden imposed by various cardiovascular and renal toxicities of anticancer therapies. To improve the overall outcome of patients with cancer, it is essential to understand and manage these treatment-related adverse effects. The cardiovascular side effects of antineoplastic therapies are well-known and include left ventricular dysfunction, heart failure, myocardial ischaemia, QT prolongation, arrhythmia and hypertension. Among these, hypertension is the most common complication, prevalent in about 40% of all cancer patients, yet frequently overlooked and undertreated. This review explores the intricate connection between cancer and hypertension and provides distinct approaches to diagnosing, monitoring and managing hypertension in patients with cancer. We also outline the challenges and considerations that are relevant to the care of patients receiving anticancer drugs with prohypertensive potential.

Health-related quality-of-life in treatment-naive CLL/SLL patients treated with zanubrutinib versus bendamustine plus rituximab

OBJECTIVE

Zanubrutinib is a highly selective, next-generation Bruton's tyrosine kinase inhibitor. In the phase 3 SEQUOIA trial (NCT03336333), treatment with zanubrutinib resulted in significantly improved progression-free survival compared to bendamustine plus rituximab (BR) in adult patients with treatment-naïve chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) without del(17p). The current analysis compared the effects of zanubrutinib versus BR on patients' health-related quality-of-life (HRQoL).

METHODS

In the SEQUOIA trial, patient-reported outcomes (PROs) were assessed at baseline and every 12 weeks (3 cycles) using the EORTC QLQ-C30 and EQ-5D-5L. Descriptive analyses were performed on all the questionnaires' scales and a mixed model for repeated measures was performed using the key QLQ-C30 endpoints of global health status/QoL (GHS/QoL), physical and role functioning, and symptoms of fatigue, pain, diarrhea, and nausea/vomiting at weeks 12 and 24.

RESULTS

Compared with BR-treated patients, those in the zanubrutinib arm experienced greater improvements in HRQoL outcomes at both weeks 12 and 24. By week 24, mean change differences (95% confidence interval) between the arms were significant for GHS/QoL (4.9 [0.9, 9.0]), physical functioning (3.8 [0.8, 6.7]), diarrhea (-6.2 [-10.0, -2.5]), fatigue (-4.5 [-8.9, -0.1]), and nausea/vomiting (-4.5 [-8.9, -0.1]); role functioning (4.8 [-0.2, 9.7]) was marginally better in the zanubrutinib arm and there were no differences in pain symptoms (-0.4 [-4.3, 5.1]) between the arms.

CONCLUSIONS

During the first 24 weeks of treatment, zanubrutinib was associated with better HRQoL outcomes in patients with treatment-naive CLL/SLL without del(17p) compared to BR.

TRIAL REGISTRATION

The SEQUOIA trial is registered on clinicaltrials.gov as SEQUOIA trial (NCT03336333).

Rilzabrutinib versus placebo in adults and adolescents with persistent or chronic immune thrombocytopenia: LUNA 3 phase III study

Background

Immune thrombocytopenia (ITP) is characterized by primarily autoantibody-mediated platelet destruction and impaired platelet production resulting in thrombocytopenia and an increased risk of bleeding. Other manifestations include increased risk of thrombosis and diminished quality of life. Current treatment approaches are directed toward lowering the rate of platelet destruction or stimulating platelet production to prevent bleeding. Rilzabrutinib is an oral, reversible, potent Bruton tyrosine kinase inhibitor that was specifically designed to treat immune-mediated diseases and mediates its therapeutic effect through a dual mechanism of action: (1) inhibiting B-cell activation and (2) interrupting antibody-coated cell phagocytosis by Fc gamma receptor in spleen and liver. A 24-week dose-finding phase I/II study of rilzabrutinib in patients with ITP showed a 40% platelet response (⩾2 consecutive platelet counts of ⩾50 × 109/L and increase from baseline ⩾20 × 109/L without rescue medication use) and a well-tolerated safety profile with only grade 1/2 transient adverse events across dose levels.

Objectives

Assess the efficacy and safety of oral rilzabrutinib in adult and adolescent patients with persistent or chronic ITP.

Design

Rilzabrutinib 400 mg BID is being evaluated in the ongoing LUNA 3 multicenter, double-blind, placebo-controlled phase III study.

Methods and analysis

The primary endpoint is durable platelet response, defined as achieving platelet counts of ⩾50 × 109/L for at least two-thirds of ⩾8 available weekly scheduled platelet measurements during the last 12 weeks (including ⩾2 available measurements within the last 6 weeks) of the 24-week blinded treatment period in the absence of rescue therapy.

Ethics

Ethical guidelines and informed consent are followed.

Discussion

The LUNA 3 trial will further investigate rilzabrutinib's safety and efficacy in adult and adolescent patients, with the primary goal of addressing a major objective in treating patients with ITP: durability of platelet response.

Trail Registration

ClinicalTrials.gov NCT04562766: https://clinicaltrials.gov/ct2/show/NCT04562766; EU Clinical Trials Register EudraCT 2020-002063-60: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-002063-60.

Chinese expert consensus on Bruton tyrosine kinase inhibitors in the treatment of B-cell malignancies

Targeted therapy with Bruton tyrosine kinase (BTK) inhibitors have revolutionized the treatment of patients with various B-cell malignancies. BTK inhibitors such as ibrutinib, zanubrutinib, orelabrutinib, and acalabrutinib have shown good clinical efficacy and better safety profiles than those of traditional chemotherapy and chemoimmunotherapy regimens. Multiple studies on new BTK inhibitors are ongoing, which may provide more therapeutic options for the treatment of B-cell malignancies. Considering the unmet need of evidence on BTK inhibitors in all clinical settings and to standardize the use of BTK inhibitors available in mainland China, Taiwan, Hong Kong, and Macau regions, this consensus has been formulated for the treatment of various B-cell malignancies based on the clinical practice and available evidences on the use of BTK inhibitors. The recommendations of this consensus will provide guidance to physicians and clinical researchers on the effective treatment of B-cell malignancies with BTK inhibitors.

AI & experimental-based discovery and preclinical IND-enabling studies of selective BMX inhibitors for development of cancer therapeutics

The current work aims to design and provide a preliminary IND-enabling study of selective BMX inhibitors for cancer therapeutics development. BMX is an emerging target, more notably in oncological and immunological diseases. In this work, we have employed a predictive AI-based platform to design the selective inhibitors considering the novelty, IP prior protection, and drug-likeness properties. Furthermore, selected top candidates from the initial iteration of the design were synthesized and chemically characterized utilizing 1H NMR and LC-MS. Employing a panel of biochemical (enzymatic) and cancer cell lines, the selected molecules were tested against these assays. In addition, we used artificial intelligence to predict and evaluate several critical IND-focused physicochemical and pharmacokinetics values of the selected molecules. A secondary objective of the current work was also to validate the sole role of BMX in animal models known to be mediated by BMX. More than 50 molecules were designed in the present study employing five novel discovered scaffolds. Two molecules were nominated for further IND-focused studies. Compound II showed promising in-vitro activity against BMX in both enzymatic assays compared to other kinases and in cancer cell lines with known BMX overexpression. Interestingly, compound II showed very favorable physicochemical and pharmacokinetics properties as predicted by the used platforms. The animal study further confirmed the sole role of BMX in the disease model. The current work provides promising data on a selective BMX inhibitor as a potential lead for therapeutics development, and the asset is currently in the optimization stage. Notably, the current study shows a framework for a combined approach employing both AI and experimentation that can be used by academic labs in their research programs to more streamline programs into IND-focused to be bridged easily for further clinical development with industrial partners.

SOHO State of the Art Updates and Next Questions: Updates on BTK Inhibitors for the Treatment of Chronic Lymphocytic Leukemia

Over the last decade, targeted inhibition of Bruton's tyrosine kinase (BTK) has led to a paradigm shift in the way chronic lymphocytic leukemia (CLL) is managed. BTK inhibitors (BTKi) are broadly classified as covalent BTKI and noncovalent BTKi (cBTKi and ncBTK) Ibrutinib, as the first approved cBTKi, vastly improved outcomes for patients with CLL over prior chemoimmunotherapy regimens. However, long-term use is limited by both intolerance and resistance. The second generation of more selective BTKi were developed to improve tolerability. While these agents have led to an improved safety profile in comparison to Ibrutinib (both acalabrutinib and zanubrutinib), and improved efficacy (zanubrutinib), intolerance occasionally occurs, and resistance remains a challenge. The third generation of BTKi, which noncovalently or reversibly inhibits BTK, has shown promising results in early phase trials and are being evaluated in the phase 3 setting. These drugs could be an effective treatment option in patients with either resistance and intolerance to cBTKi. The most recent development in therapeutic agents targeting BTK is the development of BTK degraders. By removing BTK, as opposed to inhibiting it, these drugs could remain efficacious irrespective of BTK resistance mutations, however clinical data are limited at this time. This review summarizes the evolution and ongoing development of newer BTKi and BTK degraders in the management of CLL, with a focus of future directions in this field, including how emerging clinical data could inform therapeutic sequencing in CLL management.

Cardiovascular Toxicities of BTK Inhibitors in Chronic Lymphocytic Leukemia: JACC: CardioOncology State-of-the-Art Review

Over the past decade, the treatment landscape of chronic lymphocytic leukemia (CLL) has dramatically changed, shifting from cytotoxic chemotherapy to targeted therapies. Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the treatment of CLL and are increasingly applied in many other malignancies. However, ibrutinib, the first BTK inhibitor approved, is associated with serious toxicities, including atrial fibrillation in up to 38% of patients, ventricular arrhythmias, and other cardiovascular toxicities. Emerging data suggest several newer BTK inhibitors (eg, acalabrutinib, zanubrutinib) are still associated with cardiotoxic risks. This review examines the current state of evidence, including incidence rates, risk factors, mechanisms, and management strategies of cardiovascular toxicities with BTK inhibitors and other CLL therapies. We specifically focus on atrial fibrillation, ventricular arrhythmias/sudden death, hypertension, heart failure, bleeding, and stroke. We also touch on other emerging BTK therapies (eg, pirtobrutinib). Finally, we highlight key unanswered questions and future directions of research.

The Five "Ws" of Frailty Assessment and Chronic Lymphocytic Leukemia: Who, What, Where, Why, and When

Chronic lymphocytic leukemia (CLL) is a disease of the elderly, but chronological age does not accurately discriminate frailty status at the inter-individual level. Frailty describes a person's overall resilience. Since CLL is a stressful situation, it is relevant to assess the patient´s degree of frailty, especially before starting antineoplastic treatment. We are in the era of targeted therapies, which have helped to control the disease more effectively and avoid the toxicity of chemo (immuno) therapy. However, these drugs are not free of side effects and other aspects arise that should not be neglected, such as interactions, previous comorbidities, or adherence to treatment, since most of these medications are taken continuously. The challenge we face is to balance the risk of toxicity and efficacy in a personalized way and without forgetting that the most frequent cause of death in CLL is related to the disease. For this purpose, comprehensive geriatric assessment (GA) provides us with the opportunity to evaluate multiple domains that may affect tolerance to treatment and that could be improved with appropriate interventions. In this review, we will analyze the state of the art of GA in CLL through the five Ws.

Zanubrutinib-induced aseptic meningitis: a case report and literature review

Zanubrutinib is a Bruton tyrosine kinase (BTK) inhibitor used in B cell malignancy treatment and is generally well tolerated in most patients. Zanubrutinib-induced aseptic meningitis is currently not reported. Herein, we present the first case of zanubrutinib-induced aseptic meningitis. A 33-year-old woman was diagnosed with relapsed/refractory follicular lymphoma and subsequently developed aseptic meningitis after receiving zanubrutinib treatment. We reviewed the literature and uncovered the lack of current reports on zanubrutinib or other BTK inhibitor-induced aseptic meningitis. Moreover, we summarized cases on aseptic meningitis induced by common chemotherapy and targeted drugs used for hematological diseases. Drug-induced aseptic meningitis (DIAM) is a drug-induced meningeal inflammation. The possible pathogenesis is the direct stimulation of the meninges via intrathecal injection of chemotherapy drugs and immune hypersensitivity response caused by immunosuppressive drugs. It is more common in women with immune deficiency and mainly manifests as persistent headache and fever. Cerebrospinal fluid examinations mainly demonstrate a significant increase in cells and proteins. DIAM diagnosis needs to exclude bacterial, fungal, viral, and tuberculosis infections; neoplastic meningitis; and systemic diseases involving the meninges. The prognosis of DIAM is usually favorable, and physicians should detect and stop the causative drug. In conclusion, zanubrutinib-induced aseptic meningitis is a rare but serious complication, and physicians should be promptly aware of this adverse event to avoid serious consequences.

Detailed safety profile of acalabrutinib vs ibrutinib in previously treated chronic lymphocytic leukemia in the ELEVATE-RR trial

ELEVATE-RR demonstrated noninferior progression-free survival and lower incidence of key adverse events (AEs) with acalabrutinib vs ibrutinib in previously treated chronic lymphocytic leukemia. We further characterize AEs of acalabrutinib and ibrutinib via post hoc analysis. Overall and exposure-adjusted incidence rate was assessed for common Bruton tyrosine kinase inhibitor-associated AEs and for selected events of clinical interest (ECIs). AE burden scores based on previously published methodology were calculated for AEs overall and selected ECIs. Safety analyses included 529 patients (acalabrutinib, n = 266; ibrutinib, n = 263). Among common AEs, incidences of any-grade diarrhea, arthralgia, urinary tract infection, back pain, muscle spasms, and dyspepsia were higher with ibrutinib, with 1.5- to 4.1-fold higher exposure-adjusted incidence rates. Incidences of headache and cough were higher with acalabrutinib, with 1.6- and 1.2-fold higher exposure-adjusted incidence rate, respectively. Among ECIs, incidences of any-grade atrial fibrillation/flutter, hypertension, and bleeding were higher with ibrutinib, as were exposure-adjusted incidence rates (2.0-, 2.8-, and 1.6-fold, respectively); incidences of cardiac events overall (the Medical Dictionary for Regulatory Activities system organ class) and infections were similar between arms. Rate of discontinuation because of AEs was lower for acalabrutinib (hazard ratio, 0.62; 95% confidence interval, 0.41-0.93). AE burden score was higher for ibrutinib vs acalabrutinib overall and for the ECIs atrial fibrillation/flutter, hypertension, and bleeding. A limitation of this analysis is its open-label study design, which may influence the reporting of more subjective AEs. Overall, event-based analyses and AE burden scores demonstrated higher AE burden overall and specifically for atrial fibrillation, hypertension, and hemorrhage with ibrutinib vs acalabrutinib. This trial was registered at www.clinicaltrials.gov as #NCT02477696.

Advancements in the Treatment of CLL: The Rise of Zanubrutinib as a Preferred Therapeutic Option

Ibrutinib, the 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 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. More recently, data from the phase III ALPINE trial, which directly compared zanu with ibrutinib, demonstrated that zanu's advantages include an improved safety profile as well as 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 the most recent German CLL algorithm suggest that zanu may replace first-generation BTKis as a preferred therapeutic option for patients with CLL/SLL due to its increased selectivity for the kinase binding site, improved therapeutic efficacy, and favorable toxicity profile. Some drug class-related characteristics such as drug resistance, low complete remission (CR) rates, and indefinite treatment duration still remain with zanu, and the results from recently completed and ongoing fixed-duration clinical trials, combining zanu with an anti-BCL2 agent, are eagerly awaited with the possible promise of a reduced treatment duration and lower financial burden.

Adverse effects of tyrosine kinase inhibitors in cancer therapy: pathophysiology, mechanisms and clinical management

Since their invention in the early 2000s, tyrosine kinase inhibitors (TKIs) have gained prominence as the most effective pathway-directed anti-cancer agents. TKIs have shown significant utility in the treatment of multiple hematological malignancies and solid tumors, including chronic myelogenous leukemia, non-small cell lung cancers, gastrointestinal stromal tumors, and HER2-positive breast cancers. Given their widespread applications, an increasing frequency of TKI-induced adverse effects has been reported. Although TKIs are known to affect multiple organs in the body including the lungs, liver, gastrointestinal tract, kidneys, thyroid, blood, and skin, cardiac involvement accounts for some of the most serious complications. The most frequently reported cardiovascular side effects range from hypertension, atrial fibrillation, reduced cardiac function, and heart failure to sudden death. The potential mechanisms of these side effects are unclear, leading to critical knowledge gaps in the development of effective therapy and treatment guidelines. There are limited data to infer the best clinical approaches for the early detection and therapeutic modulation of TKI-induced side effects, and universal consensus regarding various management guidelines is yet to be reached. In this state-of-the-art review, we examine multiple pre-clinical and clinical studies and curate evidence on the pathophysiology, mechanisms, and clinical management of these adverse reactions. We expect that this review will provide researchers and allied healthcare providers with the most up-to-date information on the pathophysiology, natural history, risk stratification, and management of emerging TKI-induced side effects in cancer patients.

Preclinical characterization of pirtobrutinib, a highly selective, noncovalent (reversible) BTK inhibitor

Bruton tyrosine kinase (BTK), a nonreceptor tyrosine kinase, is a major therapeutic target for B-cell-driven malignancies. However, approved covalent BTK inhibitors (cBTKis) are associated with treatment limitations because of off-target side effects, suboptimal oral pharmacology, and development of resistance mutations (eg, C481) that prevent inhibitor binding. Here, we describe the preclinical profile of pirtobrutinib, a potent, highly selective, noncovalent (reversible) BTK inhibitor. Pirtobrutinib binds BTK with an extensive network of interactions to BTK and water molecules in the adenosine triphosphate binding region and shows no direct interaction with C481. Consequently, pirtobrutinib inhibits both BTK and BTK C481 substitution mutants in enzymatic and cell-based assays with similar potencies. In differential scanning fluorimetry studies, BTK bound to pirtobrutinib exhibited a higher melting temperature than cBTKi-bound BTK. Pirtobrutinib, but not cBTKis, prevented Y551 phosphorylation in the activation loop. These data suggest that pirtobrutinib uniquely stabilizes BTK in a closed, inactive conformation. Pirtobrutinib inhibits BTK signaling and cell proliferation in multiple B-cell lymphoma cell lines, and significantly inhibits tumor growth in human lymphoma xenografts in vivo. Enzymatic profiling showed that pirtobrutinib was highly selective for BTK in >98% of the human kinome, and in follow-up cellular studies pirtobrutinib retained >100-fold selectivity over other tested kinases. Collectively, these findings suggest that pirtobrutinib represents a novel BTK inhibitor with improved selectivity and unique pharmacologic, biophysical, and structural attributes with the potential to treat B-cell-driven cancers with improved precision and tolerability. Pirtobrutinib is being tested in phase 3 clinical studies for a variety of B-cell malignancies.

Pharmacovigilance analysis of cardiac risks associated with Bruton tyrosine kinase inhibitors

BACKGROUND

Bruton tyrosine kinase inhibitors (BTKIs) can be associated with several cardiac risks.

RESEARCH DESIGN AND METHODS

The study was conducted based on records from a large spontaneous reporting database, the Food and Drug Administration Adverse Event Reporting System, for cardiac events reported for several BTKI agents. Reporting odds ratio and information components based on statistical shrinkage transformation were utilized to measure disproportionality.

RESULTS

The final number of records for BTKI-related cardiac events was 10 320. Death or life-threatening events occurred in 17.63% of all associated cardiac records. Significant reporting was captured between BTKI (total/specific) and cardiac events, with the strongest association for ibrutinib. A total of 47 positive signals were evacuated for ibrutinib, with atrial fibrillation being the most commonly reported one. Concomitantly, cardiac failure, congestive, cardiac disorder, arrhythmia, pericardial effusion, and atrial flutter were also noticed for relatively stronger signal and disproportionality. Atrial fibrillation was over-reported in the three groups (ibrutinib, acalabrutinib, and zanubrutinib), and acalabrutinib had statistically significant lower reporting compared with ibrutinib.

CONCLUSIONS

Receiving ibrutinib, acalabrutinib, or zanubrutinib might increase the chance of cardiac complications, with ibrutinib posing the highest risk. The type of cardiotoxicity involved in ibrutinib was highly variable.

Bruton tyrosine kinase inhibitors for multiple sclerosis

Current therapies for multiple sclerosis (MS) reduce both relapses and relapse-associated worsening of disability, which is assumed to be mainly associated with transient infiltration of peripheral immune cells into the central nervous system (CNS). However, approved therapies are less effective at slowing disability accumulation in patients with MS, in part owing to their lack of relevant effects on CNS-compartmentalized inflammation, which has been proposed to drive disability. Bruton tyrosine kinase (BTK) is an intracellular signalling molecule involved in the regulation of maturation, survival, migration and activation of B cells and microglia. As CNS-compartmentalized B cells and microglia are considered central to the immunopathogenesis of progressive MS, treatment with CNS-penetrant BTK inhibitors might curtail disease progression by targeting immune cells on both sides of the blood-brain barrier. Five BTK inhibitors that differ in selectivity, strength of inhibition, binding mechanisms and ability to modulate immune cells within the CNS are currently under investigation in clinical trials as a treatment for MS. This Review describes the role of BTK in various immune cells implicated in MS, provides an overview of preclinical data on BTK inhibitors and discusses the (largely preliminary) data from clinical trials.

How We Manage Patients with Indolent B-Cell Malignancies on Bruton's Tyrosine Kinase Inhibitors: Practical Considerations for Nurses and Pharmacists

The most common forms of B-cell malignancy, non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), have seen a drastic shift in the treatment landscape over the last two decades with the introduction of targeted agents. Among them are Bruton's tyrosine kinase (BTK) inhibitors, which have demonstrated excellent efficacy in indolent B-cell NHLs and CLL. Although BTK inhibitors are generally thought to be more tolerable than chemoimmunotherapy, they are associated with a unique safety profile including varying rates of rash, diarrhea, musculoskeletal events, cardiovascular events, and bleeding. Ibrutinib was the first BTK inhibitor to gain a Health Canada indication, followed by second-generation BTK inhibitors acalabrutinib and zanubrutinib, which have better safety profiles compared to ibrutinib, likely due to their improved selectivity for BTK. As BTK inhibitors are oral agents given continuously until disease progression, long-term adverse event (AE) monitoring and management as well as polypharmacy considerations are important for maintaining patient quality of life. This paper intends to serve as a reference for Canadian nurses and pharmacists on dosing, co-administration, and AE management strategies when caring for patients with indolent B-cell NHL or CLL being treated with BTK inhibitors.

Transcriptomic profiles and 5-year results from the randomized CLL14 study of venetoclax plus obinutuzumab versus chlorambucil plus obinutuzumab in chronic lymphocytic leukemia

Data on long-term outcomes and biological drivers associated with depth of remission after BCL2 inhibition by venetoclax in the treatment of chronic lymphocytic leukemia (CLL) are limited. In this open-label parallel-group phase-3 study, 432 patients with previously untreated CLL were randomized (1:1) to receive either 1-year venetoclax-obinutuzumab (Ven-Obi, 216 patients) or chlorambucil-Obi (Clb-Obi, 216 patients) therapy (NCT02242942). The primary endpoint was investigator-assessed progression-free survival (PFS); secondary endpoints included minimal residual disease (MRD) and overall survival. RNA sequencing of CD19-enriched blood was conducted for exploratory post-hoc analyses. After a median follow-up of 65.4 months, PFS is significantly superior for Ven-Obi compared to Clb-Obi (Hazard ratio [HR] 0.35 [95% CI 0.26-0.46], p < 0.0001). At 5 years after randomization, the estimated PFS rate is 62.6% after Ven-Obi and 27.0% after Clb-Obi. In both arms, MRD status at the end of therapy is associated with longer PFS. MRD + ( ≥ 10-4) status is associated with increased expression of multi-drug resistance gene ABCB1 (MDR1), whereas MRD6 (< 10-6) is associated with BCL2L11 (BIM) expression. Inflammatory response pathways are enriched in MRD+ patient solely in the Ven-Obi arm. These data indicate sustained long-term efficacy of fixed-duration Ven-Obi in patients with previously untreated CLL. The distinct transcriptomic profile of MRD+ status suggests possible biological vulnerabilities.

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.