Bruton's Tyrosine Kinase Research Articles

Abstract PO-025: Identifying tissue-specific drivers of immune evasion in Mantle Cell Lymphoma at single cell level

Abstract Background: Mantle cell lymphoma (MCL) is an aggressive subtype of B-cell non-Hodgkin lymphoma that exhibits clinical, pathological, and genetic heterogeneity. While generally thought to be incurable, recently demonstrated clinical activity of both chimeric antigen receptor T (CAR-T) cells and bispecific antibodies suggest that immune-mediated therapies offer substantial benefit in this disease and underscores the value of understanding mechanisms of immune evasion in this disease. Aim: The aim of this project is to uncover distinct cellular networks driving immune evasion in MCL across disease sites. Methods: We analyzed 10 archival samples collected from 8 clinically annotated patients with untreated MCL, including mononuclear cells from peripheral blood (PB), lymph nodes (LN) and bone marrow (BM). After generating single-cell suspensions from tumors, we performed Cellular Indexing of Transcriptomes and Epitopes sequencing (CITE-seq) and identified malignant B cells based on the co-expression of cyclin D1 (CCND1) and B cell markers (MS4A1, CD79A, CD79B). B and T cells were then subclustered using a reference mapping geneset. Molecular signatures database was utilized to perform geneset enrichment analysis (GSEA). Results: Our study first confirms the heterogeneity of mantle cell lymphoma across compartments (i.e PB, LN, BM), showing 5 different clusters of malignant cells, with different abundance in cell proportion among patients. We found that malignant B cells expressed different levels of CCND1 expression across tissue compartments. Furthermore, we identified a specific cluster of malignant cells, enriched in the PB, marked by decreased expression of the costimulatory receptor CD40 and higher levels of B-cell receptor signaling. This may explain the rapid response of circulating MCL cells to Bruton Tyrosine Kinase (BTK) inhibition. Interestingly, the higher expression of CD40 on LN-resident MCL cells suggests that MCL cells may co-opt LN-resident T-cells to support their growth, as has been previously described. Consistent with this, T-cells from LN were phenotypically exhausted, suggesting that MCL cells within the LN leverage local interactions with T-cells to promote survival while avoiding T-cell-driven cytotoxicity. Finally, we also found that high level of Ki67 correlates with myeloid-cell abundance in the TME suggesting that monocytes may support tumor cell proliferation. Conclusion: These results provide a deeper understanding of tissue-specific heterogeneity in MCL, including distinct tumor-immune interactions at different tissue sites. In ongoing analyses, we will correlate these findings with patient outcomes and response to BTK inhibition and are currently analyzing samples from patients with relapsed disease to identify microenvironmental features associated with disease progression. Citation Format: Amira Marouf, Jahan Rahman, Ashlee Joseph, Irem Isgor, Ya-Hui Lin, Ronan Chaligne, Shenon Sethi, Ahmet Dogan, Gilles Salles, Anita Kumar, Santosha A Vardhana. Identifying tissue-specific drivers of immune evasion in Mantle Cell Lymphoma at single cell level [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PO-025.

Impaired Cardiac AMPK (5'-Adenosine Monophosphate-Activated Protein Kinase) and Ca2+-Handling, and Action Potential Duration Heterogeneity in Ibrutinib-Induced Ventricular Arrhythmia Vulnerability.

We recently demonstrated that acute administration of ibrutinib, a Bruton's tyrosine kinase inhibitor used in chemotherapy for blood malignancies, increases ventricular arrhythmia (VA) vulnerability. A pathway of ibrutinib-induced vulnerability to VA that can be modulated for cardioprotection remains unclear. The effects of ibrutinib on cardiac electrical activity and Ca2+ dynamics were investigated in Langendorff-perfused hearts using optical mapping. We also conducted Western blotting analysis to evaluate the impact of ibrutinib on various regulatory and Ca2+-handling proteins in rat cardiac tissues. Treatment with ibrutinib (10 mg/kg per day) for 4 weeks was associated with an increased VA inducibility (72.2%±6.3% versus 38.9±7.0% in controls, P<0.002) and shorter action potential durations during pacing at various frequencies (P<0.05). Ibrutinib also decreased heart rate thresholds for beat-to-beat duration alternans of the cardiac action potential (P<0.05). Significant changes in myocardial Ca2+ transients included lower amplitude alternans ratios (P<0.05), longer times-to-peak (P<0.05), and greater spontaneous intracellular Ca2+ elevations (P<0.01). We also found lower abundance and phosphorylation of myocardial AMPK (5'-adenosine monophosphate-activated protein kinase), indicating reduced AMPK activity in hearts after ibrutinib treatment. An acute treatment with the AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside ameliorated abnormalities in action potential and Ca2+ dynamics, and significantly reduced VA inducibility (37.1%±13.4% versus 72.2%±6.3% in the absence of 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, P<0.05) in hearts from ibrutinib-treated rats. VA vulnerability inflicted by ibrutinib may be mediated in part by an impairment of myocardial AMPK activity. Pharmacological activation of AMPK may be a protective strategy against ibrutinib-induced cardiotoxicity.

The role of Bruton's tyrosine kinase in pathogenesis of chronic spontaneous urticaria and the prospects for the use of new treatment

Chronic spontaneous urticaria is a fairly common disease with an unpredictable course, burdensome symptoms and a significant negative impact on patients` quality of life. Despite the established stepwise approach to treatment with antihistamines in standard and increased dosages, anti-IgE therapy, there remains a portion of patients with unsatisfactory control of urticaria symptoms, with the need to develop drugs that target new therapeutic targets. Mast cells, basophils and B cells are key cells involved in the pathogenesis of urticaria; activation, differentiation, proliferation, cytokine secretion and degranulation in all three types of cells is regulated via Bruton's tyrosine kinase signalling pathway through FcεRI and BCR receptors respectively. Inhibition of Bruton's tyrosine kinase is being developed as a new therapeutic strategy for chronic spontaneous urticaria. Here we present overview of the current understanding of chronic spontaneous urticarial`s pathogenesis, the role of Bruton's tyrosine kinase, the history of medical use of Bruton's tyrosine kinase inhibitors, as well as clinical data on the use of new Bruton's tyrosine kinase inhibitors in patients with chronic spontaneous urticaria who have not achieved adequate disease control with antihistamines.

EE506 Clinical Consequences and Associated Costs of Treating Patients With Waldenström Macroglobulinemia in the First-Line Setting With Bruton Tyrosine Kinase Inhibitors

EE506 Clinical Consequences and Associated Costs of Treating Patients With Waldenström Macroglobulinemia in the First-Line Setting With Bruton Tyrosine Kinase Inhibitors

Fixed-duration pirtobrutinib plus venetoclax with or without rituximab in relapsed/refractory CLL: the phase 1b BRUIN trial

AbstractPirtobrutinib is a highly selective, noncovalent (reversible) Bruton tyrosine kinase inhibitor (BTKi). Patients with relapsed or refractory (R/R) chronic lymphocytic leukemia (CLL) were treated with fixed-duration pirtobrutinib plus venetoclax (PV) or pirtobrutinib plus venetoclax and rituximab (PVR) in this phase 1b trial. Prior covalent BTKi therapy was allowed, but not prior treatment with venetoclax. Patients were assigned to receive PV (n = 15) or PVR (n = 10) for 25 cycles. Most patients (68%) had received prior covalent BTKi therapy. At the data cutoff date, the median time on study was 27.0 months for PV and 23.3 months for PVR. Overall response rates were 93.3% (95% confidence interval [CI], 68.1-99.8) for PV and 100% (95% CI, 69.2-100.0) for PVR, with 10 complete responses (PV: 7; PVR: 3). After 12 cycles of treatment, 85.7% (95% CI, 57.2-98.2) of PV and 90.0% (95% CI, 55.5-99.7) of PVR patients achieved undetectable minimal residual disease (<10-4) in peripheral blood. Progression-free survival at 18 months was 92.9% (95% CI, 59.1-99.0) for PV patients and 80.0% (95% CI, 40.9-94.6) for PVR patients. No dose-limiting toxicities were observed during the 5-week assessment period. The most common grade ≥3 adverse events (AEs) for all patients included neutropenia (52%) and anemia (16%). AEs led to dose reduction in 3 patients and discontinuation in 2. In conclusion, fixed-duration PV or PVR was well tolerated and had promising efficacy in patients with R/R CLL, including patients previously treated with a covalent BTKi. This trial was registered at www.clinicaltrials.gov as #NCT03740529.

Molecular characterisation of lupus low disease activity state (LLDAS) and DORIS remission by whole-blood transcriptome-based pathways in a pan-European systemic lupus erythematosus cohort

ObjectivesTo unveil biological milieus underlying low disease activity (LDA) and remission versus active systemic lupus erythematosus (SLE).MethodsWe determined differentially expressed pathways (DEPs) in SLE patients from the PRECISESADS project (NTC02890121)...

Impact of ibrutinib dose adjustment on TTNT in first-line CLL/SLL: a real-world analysis using target trial emulation

AbstractIbrutinib, a once-daily Bruton tyrosine kinase inhibitor, is a standard-of-care first-line (1L) treatment for patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Dosing flexibility (adjustment to daily dose of <420 mg/d) with ibrutinib can help prevent recurrence or worsening of adverse events while maintaining long-term efficacy. This study compared time to next treatment among patients with CLL/SLL in the United States initiating 1L single-agent ibrutinib at 420 mg/d (index date) and staying on this dose vs patients with dose adjustment (DA) within 3 to 12 months. Two databases were used: Komodo claims (a majority from community practices) and Acentrus electronic medical records (from academic and nonteaching hospital systems). To account for immortal time bias (patients with DA survived on 1L therapy until DA) and overlap between follow-up time and definition of treatment strategies, a target trial emulation approach was used, in which patients were cloned at index date and contributed follow-up to both treatment strategy arms until deviation from the strategy. Among 3343 patients in Komodo (mean age: 67.5 years; 37.6% female) and 1171 patients in Acentrus (mean age: 70.4 years; 34.6% female) who initiated 1L single-agent ibrutinib 420 mg/d, 18.0% and 19.6%, respectively, had a DA. DA was not associated with an increased risk of having a next treatment in both databases (adjusted hazard ratio [95% confidence interval]: Komodo: 0.95 [0.80-1.14], Acentrus: 1.14 [0.80-1.62]). These findings suggest that a flexible dosing approach with ibrutinib may be effective in allowing patients to achieve optimal outcomes while remaining on long-term continuous 1L treatment.

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

AbstractBruton'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.

Navigating the complex terrain of hepatitis B virus reactivation in the era of Bruton tyrosine kinase inhibitors

In this editorial, we offer a summary of the risk associated with hepatitis B reactivation (HBVr) in the setting of both solid and hematologic malignancies treated with Bruton tyrosine kinase (BTK) inhibitors, with insights derived from current studies. Furthermore, we emphasize the critical need for a framework regarding robust risk evaluation in patients undergoing such treatments. This framework is essential for identifying those at increased risk of HBVr, enabling healthcare providers to implement proactive measures to prevent reactivation and ensure the safe administration of BTK inhibitor therapy.

Safety of Extended Pirtobrutinib Exposure in Relapsed and/or Refractory B-Cell Malignancies.

Pirtobrutinib, a highly selective, noncovalent (reversible) Bruton tyrosine kinase inhibitor, has demonstrated promising efficacy in B-cell malignancies and is associated with low rates of discontinuation and dose reduction. Pirtobrutinib is administered until disease progression or toxicity, necessitating an understanding of the safety profile in patients with extended treatment. Here we report the safety of pirtobrutinib in patients with relapsed/refractory B-cell malignancies with extended (≥12 months) drug exposure from the BRUIN trial. Assessments included median time-to-first-occurrence of adverse events (AEs), dose reductions, and discontinuations due to treatment-emergent AEs (TEAEs) and select AEs of interest (AESIs). Of 773 patients enrolled, 326 (42%) received treatment for ≥12 months. In the extended exposure cohort, the median time-on-treatment was 19 months. The most common all-cause TEAEs were fatigue (32%) and diarrhea (31%). TEAEs leading to dose reduction occurred in 23 (7%) and discontinuations in 11 (3%) extended exposure patients. One patient had a fatal treatment-related AE (COVID-19 pneumonia). Infections (73.0%) were the most common AESI with a median time-to-first-occurrence of 7.4 months. Majority of TEAEs and AESIs occurred during the first year of therapy. Pirtobrutinib therapy continues to demonstrate an excellent safety profile amenable to long-term administration without evidence of new or worsening toxicity signals.

Discovery of a novel BTK inhibitor S-016 and identification of a new strategy for the treatment of lymphomas including BTK inhibitor-resistant lymphomas.

Bruton's tyrosine kinase (BTK) has emerged as a therapeutic target for B-cell malignancies, which is substantiated by the efficacy of various irreversible or reversible BTK inhibitors. However, on-target BTK mutations facilitating evasion from BTK inhibition lead to resistance that limits the therapeutic efficacy of BTK inhibitors. In this study we employed structure-based drug design strategies based on established BTK inhibitors and yielded a series of BTK targeting compounds. Among them, compound S-016 bearing a unique tricyclic structure exhibited potent BTK kinase inhibitory activity with an IC50 value of 0.5 nM, comparable to a commercially available BTK inhibitor ibrutinib (IC50 = 0.4 nM). S-016, as a novel irreversible BTK inhibitor, displayed superior kinase selectivity compared to ibrutinib and significant therapeutic effects against B-cell lymphoma both in vitro and in vivo. Furthermore, we generated BTK inhibitor-resistant lymphoma cells harboring BTK C481F or A428D to explore strategies for overcoming resistance. Co-culture of these DLBCL cells with M0 macrophages led to the polarization of M0 macrophages toward the M2 phenotype, a process known to support tumor progression. Intriguingly, we demonstrated that SYHA1813, a compound targeting both VEGFR and CSF1R, effectively reshaped the tumor microenvironment (TME) and significantly overcame the acquired resistance to BTK inhibitors in both BTK-mutated and wild-type BTK DLBCL models by inhibiting angiogenesis and modulating macrophage polarization. Overall, this study not only promotes the development of new BTK inhibitors but also offers innovative treatment strategies for B-cell lymphomas, including those with BTK mutations.

Real-World Treatment Patterns, Survival, and Economic Burden Among Elderly MCL Patients Previously Treated With cBTKis

BackgroundWhile covalent Bruton's tyrosine kinase inhibitors (cBTKis) have become a standard of care treatment for relapsed/refractory mantle cell lymphoma (R/R MCL), response duration is limited and resistance to BTKi and/or adverse events develop in a subset of patients. However, little real-world evidence on post-cBTKi clinical and economic outcomes exists for these patients. Patients and MethodsThis retrospective study used 2010 to 2019 U.S. Medicare claims, to identify elderly (≥ 66 years) patients with newly-diagnosed MCL who received third-line (3L) treatment and had evidence of cBTKi use in a prior line of therapy. Outcomes were assessed ≥ 12-months post 3L-treatment initiation and included treatment patterns, all-cause and MCL-related HRU and costs, and overall survival. ResultsThe final sample contained 230 elderly patients with R/R MCL receiving 3L treatment who had cBTKi use in a prior line of therapy (mean age 75.0, 21.7% age > 80 years; 67.4% male; 93.9% White). Common 3L treatments included chemotherapy (26.1%), lenalidomide (18.7%), and bortezomib (18.3%); 1-quarter (25.7%) of patients received a cBTKi (17.8% ibrutinib; 7.8% acalabrutinib). Overall survival was poor from 3L treatment initiation (median OS = 9.4 months; 1-years survival rate = 43.7%). Patients exhibited high rates of HRU (73.6% experienced hospitalization) and substantial costs ($145,726) in the 12-months after 3L initiation. ConclusionA large unmet need exists in this patient subpopulation, highlighting the importance of ongoing development of novel therapeutics.

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.

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. 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). 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. 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.

Bruton's tyrosine kinase inhibitor-related cardiotoxicity: The quest for predictive biomarkers and improved risk stratification.

Ibrutinib was the first Bruton's tyrosine kinase (BTK) inhibitor approved for the treatment of patients with chronic lymphocytic leukemia (CLL). While producing durable responses and prolonging survival, roughly 20-25% of patients experience dose limiting side effects, mostly consisting of cardiovascular toxicities like severe hypertension and atrial fibrillation. While clinical predictors of BTK inhibitor-related cardiotoxicity have been proposed and may aid in risk stratification, there is no routine risk model used in clinical practice today to identify patients at highest risk. A recent study investigating genetic predictors of ibrutinib-related cardiotoxicity found that single nucleotide polymorphisms in KCNQ1 and GATA4 were significantly associated with cardiotoxic events. If replicated in larger studies, these biomarkers may improve risk stratification in combination with clinical factors. A clinicogenomic risk model may aid in identifying patients at highest risk of developing BTK inhibitor-related cardiotoxicity in which further risk mitigation strategies may be explored.

A first-in-human study of the potent and highly selective BTK degrader ABBV-101 in patients with relapsed/refractory B-cell malignancies.

TPS7091 Background: Bruton tyrosine kinase (BTK) is a clinically validated target with an integral role in the proliferation and survival of neoplastic cells in several B-cell malignancies. Inhibitors of BTK, such as ibrutinib, have revolutionized the treatment landscape for B-cell malignancies. However, long-term use can lead to disease progression and clinical resistance associated with mutations in BTK. ABBV-101 is a reversible BTK degrader. By preclinical kinome profiling, ABBV-101 has demonstrated high selectivity with the potential for best-in-class AE profile. ABBV-101 has also shown potent activity against BTK wildtype and multiple therapy-resistant mutant forms. Degradation eliminates BTK scaffolding and enzymatic functions, which has led to deeper, more durable responses vs covalent and reversible BTKi in animal models (Pan C, et al. ASH 2023). Herein, we describe the first-in-human study of ABBV-101 monotherapy in patients with relapsed/refractory B-cell NHL. Methods: This international phase 1, open-label, multicenter study (NCT05753501) is evaluating the safety, tolerability, pharmacokinetics (PK), and preliminary efficacy of ABBV-101. Eligible patients(≥18 years) have measurable disease, received ≥2 prior systemic therapies, and have no available therapies known to provide clinical benefit.Primary objectives are to characterize safety and tolerability of ABBV-101; secondary objectives are to evaluate PK and preliminary efficacy. The study is conducted in 2 parts: dose escalation (part 1) and dose expansion (part 2). Part 1 aims to establish the maximum administered dose and maximum tolerated dose of ABBV-101 guided by a Bayesian optimal interval design; additional patients may be enrolled to a previous dose level to further explore safety, PK, and efficacy. Patients with WHO-defined chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, follicular lymphoma, marginal zone lymphoma, lymphoplasmacytic lymphoma (including Waldenström macroglobulinemia), and transformed indolent NHL (including Richter’s transformation) are eligible. Part 2 will further characterize the safety and preliminary efficacy of ABBV-101; patients diagnosed with CLL/SLL (up to 3 dose cohorts) and non-germinal center DLBCL (1 cohort) are being enrolled. ABBV-101 is administered orally until disease progression, intolerable toxicity, or other study discontinuation criteria are met. Safety assessments include, but are not limited to, AEs, clinical laboratory parameters, vital signs, and ECG. Response evaluations are performed per disease-specific response criteria at screening and every 8 weeks (1st year), 3 months (2nd year), or 4 months (3rd year onward) until progressive disease. Enrollment is ongoing with active sites in the US and Japan. Clinical trial information: NCT05753501 .

An open label, single arm, multicenter phase II study of the efficacy and safety of LP-168 monotherapy for relapsed or refractory mantle cell lymphoma.

TPS7098 Background: Targeting Bruton’s tyrosine kinase (BTK) has demonstrated impressive efficacy in relapsed or refractory mantle cell lymphoma (R/R MCL). Covalent BTK inhibitors (cBTKi) have produced extended disease remission and durable responses in R/R MCL. However, patients with continuous cBTKi treatment tend to develop selection or outgrowth of resistant clones, which triggers disease relapse. Non-covalent binding BTKi has become a treatment option for patients who progressed on cBTKi. LP-168 is a highly selective next-generation inhibitor of BTK that can bind wild-type BTK covalently and C481-mutated BTK non-covalently (reversibly) Here, we propose to evaluate the safety and efficacy of LP-168 monotherapy in patients with R/R MCL. Methods: NCT05716087 is an open-label, multicenter, single-arm, phase II study to assess the efficacy, safety, tolerability, and pharmacokinetics of LP-168 in Chinese patients with R/R MCL who have failed prior cBTKi treatment. Responses were evaluated using Lugano 2014 criteria. Eligible patients with R/R MCL must show evidence of disease progression or intolerance to at least a prior cBTKi. Patients are also required to have adequate bone marrow, liver function, kidney function, and heart function, and an ECOG performance status of 0-2. Moreover, patients must have at least one measurable lesion. Key exclusion criteria include previous non-covalent BTKi or BTK proteolysis-targeting chimeras (PROTAC) treatment, uncontrolled systemic disease, active infection, central nervous system (CNS) involvement, prior history of other malignancies within two years, and current pregnancy or breastfeeding. Concomitant use of strong or moderate CYP3A4 inducers and inhibitors or OATP1B1/OATP1B3 sensitive substrates is prohibited. LP-168 is orally administered at 150mg once daily in 28-day/cycle until progressive disease (PD), unacceptable toxicity, withdrawal of consent, death, or other reasons for treatment discontinuation. In this study, the primary endpoint was ORR according to an independent review committee (IRC) assessment based on the best overall response (BOR) of PR or better per Lugano 2014 criteria. Secondary endpoints include safety evaluation, quality of life assessment, PK parameters, ORR by investigator’s assessment, and other efficacy parameters, such as complete response ratio (CRR), progression-free survival (PFS), overall survival (OS), duration of response (DOR), and time to response (TTR). First patient was enrolled on May 12, 2023. Currently 41 study sites across China are actively enrolling patients. ClinicalTrials.gov Identifier: NCT05716087. Clinical trial information: NCT05716087 .

Bruton tyrosine kinase degrader BP001 attenuates the inflammation caused by high glucose in raw264.7 cell.

BP001 is a promising small molecule compound that has been specifically designed to target and degrade Bruton's tyrosine kinases (BTK), which is known to play a crucial role in lymphoma development. Macrophages are important immune cells in inflammation regulation and immune response. In this study, we aimed to investigate the effect of BP001 on RAW264.7 macrophage activation stimulated by a high glucose environment. Our findings revealed that treatment with BP001 significantly inhibited the production of nitric oxide (NO), reactive oxygen species (ROS), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) in RAW264.7 macrophages exposed to high glucose conditions. Furthermore, we observed that BP001 treatment also down-regulated the expression of BTK in these activated macrophages. To elucidate the underlying mechanism behind these observations, we investigated the phosphorylation level of NF-κB. Our results demonstrated that BP001 treatment led to decreased phosphorylation levels of NF-κB, thereby inhibiting the level of inflammation. In addition, we also found that BP001 could restore RAW264.7 macrophages from the pro-inflammatory state to the normal phenotype and reduce the occurrence of inflammation. The regulatory function of BP001 in autoimmunity is mediated through the degradation of BTK protein, thereby attenuating macrophage activation. Additionally, BTK plays a pivotal role in transcriptional regulation by inducing NF-κB activity. Consequently, it is not difficult to understand that BP001 effectively inhibits inflammation. In conclusion, the present study provides evidence that BP001, a BTK degrader, can serve as a novel immunomodulator of inflammation induced by high glucose, making it an attractive candidate for further investigation.

RN486, a Bruton's Tyrosine Kinase inhibitor, antagonizes multidrug resistance in ABCG2-overexpressing cancer cells.

Overcoming ATP-binding cassette subfamily G member 2 (ABCG2)-mediated multidrug resistance (MDR) has attracted the attention of scientists because one of the critical factors resulting in MDR in cancer is the overexpression of ABCG2. RN486, a Bruton's Tyrosine Kinase (BTK) inhibitor, was discovered to potentially reverse ABCB1-mediated MDR. However, there is still uncertainty about whether RN486 has a reversal off-target impact on ABCG2-mediated MDR. MTT assay was used to detect the reversal effect of RN486 on ABCG2-overexpressing cancer cells. The ABCG2 expression level and subcellular localization were examined by Western blotting and immunofluorescence. Drug accumulation and eflux assay and ATPase assay were performed to analyze the ABCG2 transporter function and ATPase activity. Molecular modeling predicted the binding between RN486 and ABCG2 protein. Non-toxic concentrations of RN486 remarkably increased the sensitivity of ABCG2-overexpressing cancer cells to conventional anticancer drugs mitoxantrone and topotecan. The reversal mechanistic studies showed that RN486 elevated the drug accumulation because of reducing the eflux of ABCG2 substrate drug in ABCG2-overexpressing cancer cells. In addition, the inhibitory efect of RN486 on ABCG2-associated ATPase activity was also verified. Molecular docking study implied a strong binding afinity between RN486 and ABCG2 transporter. Meanwhile, the ABCG2 subcellular localization was not altered by the treatment of RN486, but the expression level of ABCG2 was down-regulated. Our studies propose that RN486 can antagonize ABCG2-mediated MDR in cancer cells via down-regulating the expression level of ABCG2 protein, reducing ATPase activity of ABCG2 transporter, and inhibiting the transporting function. RN486 could be potentially used in conjunction with chemotherapy to alleviate MDR mediated by ABCG2 in cancer.

BELLWAVE-010: A phase 3 study of nemtabrutinib plus venetoclax versus venetoclax plus rituximab (VR) in previously treated patients (pts) with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL).

TPS7089 Background: VR is a standard of care option for pts with CLL/SLL who have relapsed after ≥1 line of prior therapy. However, there is an unmet need for more effective treatments. Bruton tyrosine kinase (BTK) plays an important role in the pathogenesis of CLL. Nemtabrutinib is a BTK inhibitor that targets both wild type and C481-mutant forms of BTK. In the ongoing BELLWAVE-001 study, nemtabrutinib demonstrated manageable safety and durable antitumor activity in pts with R/R CLL/SLL with and without C481 mutations. The randomized, open-label, phase 3 BELLWAVE-010 study (NCT05947851) is designed to evaluate the efficacy and safety of nemtabrutinib + venetoclax versus VR as second-line or later treatment for pts with R/R CLL/SLL. Methods: Eligible pts are aged ≥18 years with active R/R CLL/SLL after ≥1 prior therapy per iwCLL 2018 criteria and an ECOG PS of 0-2. Approximately 720 pts will be enrolled in 2 parts. Part 1 is an open-label, nonrandomized dose escalation and confirmation phase to evaluate safety and determine the optimal dose of nemtabrutinib + venetoclax. Part 1 will enroll 30 pts to establish the dose of nemtabrutinib using a modified toxicity probability interval design. Pts will receive nemtabrutinib at 2 dose levels (45 mg PO QD starting dose, escalating to 65 mg PO QD) for 28 days, followed by nemtabrutinib + venetoclax (20-400 mg PO QD ramp up over 4 weeks). Part 2 is an open-label, parallel-group, randomized phase comparing the efficacy and safety of nemtabrutinib + venetoclax with VR. In part 2, approximately 690 pts will be randomly assigned 1:1 to receive either nemtabrutinib at the recommended dose for 28 days followed by the nemtabrutinib + venetoclax or venetoclax + rituximab (or rituximab biosimilar; 375 mg/m2 at week 6, followed by 500 mg/m2 every 4 weeks starting at week 10 until week 26 [total 6 doses]). Study treatment will continue for approximately 2 years or until unacceptable toxicity, disease progression, or other discontinuation criteria are met. Randomization will be stratified by BTK-C481 mutation status (detected vs not detected), geographic region (US/Canada vs Europe vs rest of world) and risk (high risk [del(17p) and/or TP53-mutated and/or IGHV-unmutated] vs low risk [absence of high-risk factors]). The primary end point for part 2 is progression-free survival by blinded independent central review (BICR) per iwCLL 2018 criteria. Secondary end points for part 2 are undetectable minimal residual disease in bone marrow at month 14 by central laboratory assessment, objective response rate (ORR), and duration of response by BICR per iwCLL 2018 criteria, overall survival, and safety. Exploratory end points are ORR including partial response with lymphocytosis, pharmacokinetics, and health-related quality of life. Recruitment is ongoing. Clinical trial information: NCT05947851 .

Risk of hypertension in patients with CLL/SLL who participated in ALPINE: A post hoc analysis.

e19016 Background: Bruton tyrosine kinase (BTK) inhibitors are an important therapeutic option for patients with CLL/SLL. The first-generation BTK inhibitor, ibrutinib (ibru), is associated with an increased risk of hypertension. Zanubrutinib (zanu) is a next-generation BTK inhibitor designed to maximize BTK occupancy and minimize toxicity with fewer off-target effects. This analysis evaluated the risk of developing hypertension based on initiation of antihypertensives (anti-HTN) in ALPINE (NCT03734016). Methods: Anti-HTN use in the zanu (n=324) and ibru (n=324) treatment arms was assessed. The definition of anti-HTN was based on Standardized Drug Grouping; concomitant anti-HTN were adjudicated by an independent hypertension specialist blinded to BTK inhibitor assignment. Time to initiating new anti-HTN and time to adding a new class of anti-HTN were assessed using the Kaplan-Meier method. Comparisons of time-to-onset endpoints were analyzed based on the log-rank test. Results: At baseline, patient characteristics were generally balanced between zanu and ibru arms (median age, 66.7 vs 67.1 y; male, 65.1% vs 71.4%; history of hypertension, 50.9% vs 50.0%; type 2 diabetes mellitus, 10.1% vs 8.9%). Among patients not on anti-HTN at baseline, 20.7% (n=35/169) of zanu- and 28.7% (n=51/178) of ibru-treated patients initiated anti-HTN during the study. Among all patients, fewer patients in the zanu arm initiated new anti-HTN (28.4% [n=92/324] vs 32.4% [n=105/324]) and the anti-HTN were initiated later (hazard ratio [HR], 0.77; P-value=.071). Additionally, statistically fewer patients in the zanu arm compared with the ibru arm started anti-HTN in a new class (24.1% [n=78/324] vs 29.3% [n=95/324]) and the anti-HTN were started later (HR, 0.72; P-value=.034). The event rates for initiation of new anti-HTN or a new class of anti-HTN were consistently lower in the zanu vs ibru arm at each timepoint (Table). Conclusions: In ALPINE, initiation of new anti-HTN or a new class of anti-HTN occurred less frequently in the zanu arm vs the ibru arm in patients with CLL/SLL. Adoption of anti-HTN occurred sooner with ibru than zanu. These findings should be considered when initiating BTK inhibitor therapy in patients with CLL/SLL who have an elevated cardiovascular risk. Clinical trial information: NCT03734016 . [Table: see text]