Long-term follow-up of MCL patients treated with single-agent ibrutinib: updated safety and efficacy results

A phase 1, open-label, randomized drug-drug interaction study of zanubrutinib with moderate or strong CYP3A inhibitors in patients with B-cell malignancies

BTK inhibitor exposure increases significantly when coadministered with CYP3A inhibitors, which may lead to dose-related toxicities. This study explored the pharmacokinetics, efficacy, and safety of zanubrutinib when coadministered with moderate or strong CYP3A inhibitors in 26 patients with relapsed or refractory B-cell malignancies. Coadministration of zanubrutinib (80 mg BID) with moderate CYP3A inhibitors fluconazole and diltiazem or zanubrutinib (80 mg QD) with strong CYP3A inhibitor voriconazole resulted in comparable exposures to zanubrutinib (320 mg QD) with AUC_0-24h geometric least squares mean ratios approaching 1 (0.94, 0.81, and 0.83, for fluconazole, diltiazem, and voriconazole, respectively). The most common treatment-emergent adverse events were contusion (26.9%), back pain (19.2%), constipation and neutropenia (15.4% each), and rash, diarrhea, and fall (11.5% each). This study supports current United States Prescribing Information dose recommendations for the coadministration of reduced-dose zanubrutinib with moderate or strong CYP3A inhibitors and confirms the favorable efficacy and safety profile of zanubrutinib.

Pevonedistat, a Nedd8-activating enzyme inhibitor, in combination with ibrutinib in patients with relapsed/refractory B-cell non-Hodgkin lymphoma

Pevonedistat (TAK924) is a Nedd8-activating enzyme inhibitor with preclinical activity in non-Hodgkin lymphoma (NHL). This open-label, Phase I, multicenter, investigator-sponsored study enrolled patients with relapsed/refractory (R/R) NHL and chronic lymphocytic leukemia (CLL). The primary objective was safety. Pevonedistat was given intravenously on days 1, 3, 5 of a 21-day cycle for 8 cycles at five dose levels (15 to 50 mg/m2); ibrutinib was administered at 420 or 560 mg orally daily continuously. Eighteen patients with NHL were enrolled, including 8 patients with mantle cell lymphoma (MCL) and 4 patients with CLL. One dose-limiting toxicity (mediastinal hemorrhage) occurred at 50 mg/m2 of pevonedistat which is the estimated maximum tolerated dose. Bruising and diarrhea were the most common adverse events (56% and 44%). Atrial fibrillation occurred in 3 patients (17%). Grade ≥3 toxicities included arthralgia, atrial fibrillation, bone pain, diarrhea, hypertension, and mediastinal hemorrhage (one patient each). The overall response rate (ORR) was 65% (100% ORR in MCL). Pevonedistat disposition was not modified by ibrutinib. scRNA-Seq analysis showed that pevonedistat downregulated NFκB signaling in malignant B-cells in vivo. Thus, pevonedistat combined with ibrutinib demonstrated safety and promising early efficacy in NHL and CLL. NAE inhibition downregulated NFκB signaling in vivo.

The Therapeutic Synergy of Selinexor and Venetoclax in Mantle Cell Lymphoma Through Induction of DNA Damage and Perturbation of the DNA Damage Response

Introduction: Mantle cell lymphoma (MCL) can be stratified into blastoid and classical subtypes based on morphological features, with the former subtype having a poorer prognosis. Despite recent advances in targeted approaches, including multiple bruton tyrosine kinase inhibitors which yield impressive clinical responses and improve prognoses, MCL remains an incurable disease with frequent relapses. Additional therapeutic interventions are therefore unmet medical needs for the management of patients with MCL. Methods: Cell viability and apoptosis assays were employed to analyze the therapeutic interaction of venetoclax combined with selinexor in MCL cells. Western blot was used to investigate the potential mechanism of action for the synergy of venetoclax in combination with selinexor in MCL cells. Results: In this study, we revealed that both blastoid and classical MCL cells were vulnerable to the cytotoxic effects of selinexor, a well-established XPO1 inhibitor, manifested by loss of cell viability and induction of cell apoptosis. Moreover, our data indicated that the addition of venetoclax to selinexor showed synergistically decreased cell viabilities and increased cell deaths in blastoid and classical MCL cells compared to each single drug treatment. Either selinexor or venetoclax treatment alone decreased MCL1 expressions and increased BAX levels in MCL cells, and these effects were further enhanced by their combined regimen. Mechanistically, our findings demonstrated that induction of DNA damage and inactivation of DNA damage response were involved in the synergistic interaction of the drug combination regimen. Conclusion: Collectively, this study might provide a potential attractive therapy option for the treatment of MCL. However, the conclusion needs additional experimental validation in in vivo models and clinical evaluations are mandatory.

Managing Waldenström's macroglobulinemia with BTK inhibitors

Bruton's tyrosine kinase (BTK) inhibition is one of the treatment standards for patients with relapsed/refractory Waldenström's macroglobulinemia (WM) and for patients with WM who are unsuitable for immunochemotherapy (ICT). It offers deep and durable responses with a manageable safety profile that is generally favorable compared with ICT regimens. However, the limitations of the first approved BTK inhibitor (BTKi), ibrutinib, include reduced efficacy in patients lacking the characteristic WM mutation (MYD88L265P) and toxicities related to off-target activity. The risk of atrial fibrillation (AF) and other cardiovascular side effects are a notable feature of ibrutinib therapy. Several next-generation covalent BTKis with greater selectivity for BTK are at various stages of development. In November 2021, zanubrutinib became the first of these agents to be approved by the European Medicines Agency for the treatment of WM. Head-to-head trial data indicate that it has comparable efficacy to ibrutinib for patients with WM overall, although it may be more effective in patients with CXCR4 mutations or wild-type MYD88. In the clinical trial setting, its greater selectivity translates into a reduced risk of cardiovascular side effects, including AF. Acalabrutinib, which is pre-approval in WM, appears to offer similar advantages over ibrutinib in terms of its safety profile. Beyond the next-generation covalent BTKis, non-covalent BTKis are an emerging class with the potential to provide a therapeutic option for patients who relapse on covalent BTKis. In the future, BTKis may be increasingly utilized within combination regimens. Several ongoing trials in WM are investigating the potential for BTKi use in combination with established and novel targeted agents.

Mixed Diffuse and Tumoral Form of Bing-Neel Syndrome Successfully Treated with Ibrutinib

Introduction

Bing-Neel syndrome (BNS) is a rare and heterogenous manifestation of Waldenström macroglobulinemia (WM) involving central nervous system (CNS) infiltration by malignant lymphoplasmacytic cells. Efforts to standardize diagnostic criteria have improved in recent years, as have treatment options including the use of the Bruton tyrosine kinase inhibitor (BTKI) ibrutinib.

Case Presentation

Here, we present the case of a 70-year-old male with a remote history of WM previously treated with bendamustine and rituximab, who presented to medical attention with several months of left-sided weakness, headache, and ataxia. Brain magnetic resonance imaging revealed numerous enhancing masses in the bilateral cerebral hemispheres, inferior medulla, and upper cervical spine. Laboratory studies showed serum IgM lambda monoclonal gammopathy and elevated free serum kappa and lambda light chains, while cerebrospinal fluid flow cytometry revealed CD19+ B cells. Stereotactic brain biopsy of a right frontal brain lesion was consistent with lymphoplasmacytic lymphoma, confirmed by a positive MYD88 L265P mutation. He received ibrutinib 420 mg orally daily, and this resulted in appreciable clinical and radiologic responses, which have persisted over a 31-month period.

Conclusion

The advent of molecularly targeted agents and novel therapies for WM has provided patients and clinicians with additional therapeutic options. The use of BTK inhibitors with their high-level CNS penetrance, in particular, offers a novel way to treat BNS and improve patient overall survival while maintaining a high level of quality of life. We discuss the importance of MYD88 L265P testing in the context of BNS as well as the expanding role of BTKIs in treating this disease.

Resistance to Bruton tyrosine kinase inhibition in chronic lymphocytic leukaemia and non-Hodgkin lymphoma

Bruton tyrosine kinase inhibitors (BTKi) have transformed the therapeutic landscape of chronic lymphocytic leukaemia (CLL) and non-Hodgkin lymphoma. However, primary and acquired resistance to BTKi can be seen due to a variety of mechanisms including tumour intrinsic and extrinsic mechanisms such as gene mutations, activation of bypass signalling pathways and tumour microenvironment. Herein, we provide an updated review of the key clinical data of BTKi treatment in CLL, mantle cell lymphoma, and diffuse large B-cell lymphoma (DLBCL). We incorporate the most recent findings regarding mechanisms of resistance to covalent and non-covalent inhibitors, including ibrutinib, acalabrutinib, zanubrutinib and pirtobrutinib. We also cover the clinical sensitivity of certain molecular subtypes of DLBCL to an ibrutinib-containing regimen. Lastly, we summarise ongoing clinical investigations aimed at overcoming resistance via use of BTKi-containing combined therapies or the novel non-covalent BTKi. The review article targets an audience of clinical practitioners, clinical investigators and translational researchers.

USP14 promotes the malignant progression and ibrutinib resistance of mantle cell lymphoma by stabilizing XPO1

Background: Mantle cell lymphoma (MCL) is a heterogeneous disease belonging to non-Hodgkin's lymphoma. In recent years, the morbidity rate of MCL is ascending, and the prognosis remains unfavorable. Ubiquitin-specific proteases14 (USP14) has been evidenced to be engaged in the process of malignant tumors. In this article, the role of USP14 in the malignant process of MCL and the mechanism of ibrutinib resistance were discussed. Methods: Through qRT-PCR and western blot, the mRNA and protein expressions of USP14 in MCL cells were tested. USP14 interference plasmid was constructed by cell transfection technology, and then CCK8 and EdU assays were applied to appraise cell proliferation. Cell cycle and cell apoptosis were estimated by flow cytometry and western blot. The sensitivity of MCL cells to ibrutinib was also investigated. Next, western blot, co-IP, Cycloheximide (CHX) assay and other techniques were used to detect the relationship between USP14 and XPO1. Finally, by simultaneously inhibiting USP14 and overexpressing XPO1, the impacts of USP14 on the malignant process of MCL and the regulatory mechanism of ibrutinib sensitivity in MCL were discussed. Results: USP14 expression was markedly fortified in MCL cell lines. Interference of USP14 suppressed MCL cell viability, potentiated cell cycle arrest, apoptosis, and ibrutinib sensitivity. This process might be achieved by USP14 deubiquitination through enhancing XPO1 stability. Conclusion: USP14 can promote the malignant progression and ibrutinib sensitivity of MCL by stabilizing XPO1.

Long-term safety profile of tirabrutinib: final results of a Japanese Phase I study in patients with relapsed or refractory B-cell malignancies

Tirabrutinib is a Bruton's tyrosine kinase inhibitor for treating B-cell malignancies. We report the final results of a Phase I study of tirabrutinib in 17 Japanese patients with B-cell malignancies. Patients were administered tirabrutinib at a dose of 160 mg, 320 mg, or 480 mg once daily, or 300 mg twice daily (N = 3, 3, 4, and 7, respectively). Three patients continued tirabrutinib until study completion (November 30, 2020). Adverse events (AEs) occurred in all 17 patients, with Grade 3-4 AEs in 8 (47.1%), serious AEs in 7 (41.2%), drug-related AEs in 16 (94.1%), and Grade 3-4 drug-related AEs in 6 (35.3%). Drug-related AEs reported in 3 or more patients were rash, vomiting, neutropenia, arthralgia, and malaise. One additional serious AE (benign neoplasm of the lung, unrelated to tirabrutinib) occurred after the previous data cutoff (January 4, 2018). Tirabrutinib administration and response assessment were continued for over 4 years in 4 patients. The overall response rate was 76.5% (13/17 patients). The median (range) time to response and duration of response were 0.9 (0.9-5.9) months and 2.59 (0.08-5.45) years, respectively. These findings demonstrate the long-term safety and efficacy of tirabrutinib in Japanese patients with B-cell malignancies.Clinical trial registration: JapicCTI-142682 ( http://www.clinicaltrials.jp/ ).

The Btk inhibitor AB-95-LH34 potently inhibits atherosclerotic plaque-induced thrombus formation and platelet procoagulant activity

BACKGROUND

New antithrombotic therapies with less effect on bleeding are needed for coronary artery disease. The Btk inhibitor ibrutinib blocks atherosclerotic plaque-mediated thrombus formation. However, it is associated with increased bleeding, possibly due to non-Btk-mediated effects. Btk-deficient patients do not have bleeding issues, suggesting selective Btk inhibition as a promising antithrombotic strategy.

OBJECTIVES

To compare the antithrombotic effects of the highly selective Btk inhibitor AB-95-LH34 (LH34) with ibrutinib.

METHODS

Glycoprotein VI and G-protein coupled receptor-mediated platelet function and signaling were analyzed in healthy human donor platelets by lumi-aggregometry, flow adhesion, and western blot following 1 h treatment with inhibitors in vitro.

RESULTS

LH34 showed similar inhibition of Btk-Y223 phosphorylation as ibrutinib, but had no off-target inhibition of Src-Y418 phosphorylation. Similar dose-dependent inhibition of aggregation to atherosclerotic plaque material was observed for both. However, in response to Horm collagen, which also binds integrin α2β1, LH34 exhibited less marked inhibition than ibrutinib. Both LH34 and ibrutinib inhibited platelet adhesion and aggregation to plaque material at arterial shear. Ibrutinib demonstrated the most potent effect, with complete blockade at high concentrations. Platelet activation (P-selectin) and procoagulant activity (phosphatidylserine exposure) in thrombi were inhibited by LH34 and completely blocked by ibrutinib at high concentrations. Furthermore, plaque-induced thrombin generation was reduced by higher concentrations of LH34 and ibrutinib.

CONCLUSIONS

LH34 potently inhibits atherosclerotic plaque-induced thrombus formation and procoagulant platelet activity in vitro, with less off-target inhibition of Src than ibrutinib, suggesting it is a promising antiplatelet therapy with the potential for reduced bleeding side effects.

Efficacy and safety of ibrutinib in mantle cell lymphoma: A systematic review and meta-analysis

OBJECTIVES

Since the US Food and Drug Administration (FDA) approved ibrutinib to treat patients with refractory/relapsed mantle cell lymphoma (R/R MCL), it is used in clinical trials, whether as a single agent or in combination with other chemotherapy agents. The efficacy and safety of ibrutinib administration alone or in combinations have not been studied systematically. This study systematically reviewed the efficacy and safety of ibrutinib-containing regimens for the treatment of patients with MCL.

EVIDENCE ACQUISITION

We performed a systematic search in PubMed, Cochrane CENTRAL, Embase, Web of Science, and Scopus. Then, a team of independent reviewers selected relevant studies and extracted the data.

RESULTS

From a total of 1,436 studies, 12 trials were eligible. The overall response rates (ORRs) of patients with R/R MCL receiving single-agent ibrutinib ranged between 62.7% to 93.8%, and the ORRs of ibrutinib combinations ranged from 74 to 88%. In patients with newly diagnosed MCL receiving ibrutinib and rituximab, ORR ranged from 84 to 100%. The highest progression-free survival (PFS) was reported in patients receiving ibrutinib and rituximab (43 months). The meta-analysis performed on adverse events (AEs) demonstrated that single-agent ibrutinib had a high risk of bleeding, nausea, and diarrhea.

CONCLUSION

Single-agent ibrutinib showed acceptable efficacy and safety in the treatment of patients with MCL. Moreover, combining ibrutinib with other agents such as rituximab, venetoclax, and ublituximab can increase its efficacy and reduce chemotherapy-induced resistance in most cases; however, in the case of combination therapy, patients need to be monitored more strictly in terms of AEs. In our review, the ibrutinib and rituximab combination showed promising results in patients with R/R MCL. Also, this combination showed favorable efficacy and safety in patients with newly diagnosed untreated MCL, making it a great candidate to be studied more in large and well-designed trials.

A case report of pre-eclampsia-like endothelial injury in the kidney of an 85-year-old man treated with ibrutinib

Background

Glomerular endotheliosis is the pathognomonic glomerular lesion in pre-eclampsia that has also been described in those taking tyrosine kinase inhibitors for cancer treatment. Ibrutinib is a Bruton’s tyrosine kinase inhibitor used to treat chronic lymphocytic leukemia (CLL). We report the first known case of glomerular endotheliosis on kidney biopsy in a patient on ibrutinib monotherapy.

Case presentation

The patient presented with acute on chronic kidney disease, proteinuria, low C3 and C4 and a high rheumatoid factor titer. A kidney biopsy was performed to confirm a preliminary diagnosis of membranoproliferative glomerulonephritis (MPGN), the most common glomerular disease in patients with CLL. Unexpectedly, the kidney biopsy showed pre-eclampsia-like lesions on light and electron microscopy: occlusion of glomerular peripheral capillary lumens by swollen reactive endothelial cells. Findings of glomerulonephritis were not seen, and there were no specific glomerular immune deposits by immunofluorescence or electron microscopy.

Conclusions

CLL is known to cause glomerular lesions, mainly MPGN. There is increasing evidence that ibrutinib, a major treatment for CLL, can cause kidney disease, but the precise pathology is not characterized. We present a patient with CLL on ibrutinib with signs of glomerular endotheliosis. Based on the absence of CLL-induced kidney pathologies typically seen on the kidney biopsy and the non-selectivity of ibrutinib, we attributed the glomerular endotheliosis to ibrutinib. In pre-eclampsia, increased soluble fms-like tyrosine kinase 1 (sFlt1) levels induce endothelial dysfunction by decreasing vascular endothelial growth factor (VEGF). Ibrutinib has been demonstrated to have non-selective tyrosine kinase inhibition, including inhibition of VEGF receptor (VEGFR) and epidermal growth factor receptor (EGFR). VEGFR and EGFR inhibitors have recently been described in the literature to cause hypertension, proteinuria, and glomerular endotheliosis. Kidney biopsy should be performed in CLL patients on ibrutinib that present with acute kidney injury (AKI) or proteinuria to determine whether the clinical picture is attributable to the disease itself or a complication of the therapy.

Co-delivery of ibrutinib and hydroxychloroquine by albumin nanoparticles for enhanced chemotherapy of glioma

Ibrutinib (IBR) is an oral covalent inhibitor of Bruton's tyrosine kinase (BTK) that has been approved for the treatment of hematological malignancies. It was reported that IBR exhibited great therapeutic potential for glioma. However, the poor water solubility and high hepatic first-pass effect restrict its anti-glioma application. Meanwhile, IBR induces cytoprotective autophagy through Akt/mTOR signaling pathway, thus leading to a compromised antitumor effect. Herein, we aimed to develop a human serum albumin (HSA) based co-delivery system (IBR&HCQ HSA NPs) encapsulating IBR and hydroxychloroquine (HCQ). The bioavailability of IBR was largely improved, and enhanced sensitivity of glioma to IBR was achieved due to inhibition effect of HCQ on IBR-induced pro-survival autophagy. The physicochemical properties of IBR&HCQ HSA NPs were characterized to optimize the formulation. Biodistribution investigation revealed that HSA NPs (20 mg/kg, i.v.) dramatically increased the accumulation of IBR in glioma, which was 5.59 times higher than that of free IBR (100 mg/kg, i.g.). CCK-8 and apoptosis assays demonstrated that IBR&HCQ HSA NPs showed maximal cytotoxicity to C6 cells. In vivo studies indicated that the survival time was significantly prolonged in IBR&HCQ HSA NPs treated mice compared to those treated with IBR HSA NPs. Taken together, the HSA-based drug delivery system of IBR and HCQ opens a new avenue for efficient treatment of glioma.

Renal adverse reactions of tyrosine kinase inhibitors in the treatment of tumours: A Bayesian network meta-analysis

Objectives: Tumours remain a serious threat to human life. Following rapid progress in oncology research, tyrosine kinase inhibitors have been used to treat multiple tumour types. Given the great influence of kidneys on pharmacokinetics, renal toxicities associated with TKIs have attracted attention. However, the TKIs with the lowest risks of renal impairment are unclear. In this study, we conducted a Bayesian network meta-analysis to compare the incidence of renal impairment among different TKIs in patients with tumours. Methods and analysis: Six databases (PubMed, EMBASE, The Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang Data, and China Biomedical Literature Database) were electronically searched from inception to 1 November 2021 to identify randomized controlled trials on the incidence of renal impairment for different TKIs in patients with tumours. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. Then, a pairwise meta-analysis was conducted using Stata version 13, and network meta-analysis within the Bayesian framework was conducted using R software version 3.5.3 with the package "gemtc 0.8-2" recalling JAGS (version 4.3.0). Results: Overall, 34 randomized controlled trials were included in this study. Although renal toxicity was common among patients receiving TKIs, the incidence and severity greatly differed among the drugs and studies. Elevated creatinine and protein levels were the most common nephrotoxic events, whereas haematuria was relatively rare. Among TKIs, nintedanib and ripretinib carried the lowest risks of renal impairment. Conclusion: TKIs displayed different profiles of renal toxicity because of their different targets and underlying mechanisms. Clinicians should be aware of the risks of renal impairment to select the optimal treatment and improve patient adherence to treatment. Systematic Review Registration: [www.crd.york.ac.uk/prospero/], identifier [CRD42022295853].

Ibrutinib as monotherapy versus combination therapy in Chinese patients with relapsed/refractory mantle cell lymphoma: A multicenter study

BACKGROUND

Ibrutinib has revolutionized the treatment of mantle cell lymphoma (MCL). Both ibrutinib monotherapy and ibrutinib-based combination therapy are important salvage options for patients with relapsed/refractory (R/R) MCL. The real-world efficacy and safety profile of the two strategies in Chinese patients with R/R MCL remain unclarified.

METHODS

In the present study, data of 121 R/R MCL patients who received either ibrutinib monotherapy (N = 68) or ibrutinib combination therapy (N = 53) in 13 medical centers in China were retrospectively reviewed.

RESULTS

With a median follow-up of 20.5 months, the overall response rate was 60.3% versus 84.9% (p = 0.003), complete remission rate was 16.2% versus 43.4% (p < 0.001), and median progression-free survival (PFS) was 18.5 months (95% confidence interval [CI], 12.1-21.8) vs. 30.8 months (95% CI, 23.5-NR) (hazard ratio, 0.53 [95% CI, 0.30-0.93]; p = 0.025), with ibrutinib monotherapy and ibrutinib-based combination therapy, respectively. Subgroup analysis showed that patients with male gender, no refractory disease, Ki67 <30%, previous line of therapy = 1, non-blastoid subtype, and the number of extranodal sites involved <2 might benefits more from the combination therapy. Treatment-emergent adverse events were similar, except for a higher incidence of all grade neutropenia in the ibrutinib combination group (12.7% vs. 32.0%, p = 0.017).

CONCLUSIONS

Ibrutinib combination therapy demonstrated potentially superior efficacy and comparable tolerability to ibrutinib monotherapy. Ibrutinib-based combination therapy could be one of the prominent treatment options for R/R MCL patients.

Treatment Landscape of Relapsed/Refractory Mantle Cell Lymphoma: An Updated Review

Mantle cell lymphoma (MCL) accounts for nearly 2-6% of all non-Hodgkin lymphoma (NHL) cases, with a steady incidence increase over the past few decades. Although many patients achieve an adequate response to the upfront treatment, the short duration of remission with rapid relapse is challenging during MCL management. In this regard, there is no consensus on the best treatment options for relapsed/refractory (R/R) disease, and the international guidelines demonstrate wide variations in the recommended approaches. The last decade has witnessed the introduction of new agents in the treatment landscape of R/R MCL. Since the introduction of Bruton's tyrosine kinase (BTK) inhibitors, the treatment algorithm and response of R/R MCL patients have dramatically changed. Nevertheless, BTK resistance is common, necessitating further investigations to develop novel agents with a more durable response. Novel agents targeting the B-cell receptor (BCR) signaling have exhibited clinical activity and a well-tolerable safety profile. However, as the responses to these novel agents are still modest in most clinical trials, combination strategies were investigated in pre-clinical and early clinical settings to determine whether the combination of novel agents would exhibit a better durable response than single agents. In this report, we provide an updated literature review that covers recent clinical data about the safety and efficacy of novel therapies for the management of R/R MCL.

BTK inhibitors in the treatment of hematological malignancies and inflammatory diseases: mechanisms and clinical studies

Bruton's tyrosine kinase (BTK) is an essential component of multiple signaling pathways that regulate B cell and myeloid cell proliferation, survival, and functions, making it a promising therapeutic target for various B cell malignancies and inflammatory diseases. Five small molecule inhibitors have shown remarkable efficacy and have been approved to treat different types of hematological cancers, including ibrutinib, acalabrutinib, zanubrutinib, tirabrutinib, and orelabrutinib. The first-in-class agent, ibrutinib, has created a new era of chemotherapy-free treatment of B cell malignancies. Ibrutinib is so popular and became the fourth top-selling cancer drug worldwide in 2021. To reduce the off-target effects and overcome the acquired resistance of ibrutinib, significant efforts have been made in developing highly selective second- and third-generation BTK inhibitors and various combination approaches. Over the past few years, BTK inhibitors have also been repurposed for the treatment of inflammatory diseases. Promising data have been obtained from preclinical and early-phase clinical studies. In this review, we summarized current progress in applying BTK inhibitors in the treatment of hematological malignancies and inflammatory disorders, highlighting available results from clinical studies.

BTK Inhibitors and CAR T-Cell Therapy in Treating Mantle Cell Lymphoma-Finding a Dancing Partner

PURPOSE OF REVIEW

This review focuses on the feasibility of combining Bruton's tyrosine kinase (BTK) inhibitors (BTKis) with chimeric antigen receptor (CAR) T-cell therapy in patients with relapsed or refractory (R/R) mantle cell lymphoma (MCL). Potential scenarios for combination treatment with these agents are presented.

RECENT FINDINGS

BTKis and CAR T-cell therapy have revolutionized the treatment paradigm for R/R MCL. Ibrutinib, acalabrutinib, and zanubrutinib are covalent irreversible BTKis approved for R/R MCL. Brexucabtagene autoleucel was the first CAR T-cell therapy approved for R/R MCL based on findings from the ZUMA-2 trial. There is evidence to suggest that combination treatment with BTKis and CAR T-cell therapy may improve CAR T-cell efficacy. As BTKis and CAR T-cell therapy become mainstays in R/R MCL therapy, combination treatment strategies should be evaluated for their potential benefit in R/R MCL.

FIRE Study: Real-World Effectiveness and Safety of Ibrutinib in Clinical Practice in Patients with CLL and MCL

The FIRE study investigated the real-world effectiveness and safety of ibrutinib in prospectively observed patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and mantle cell lymphoma (MCL) in France. Patients were mostly relapsed/refractory with high-risk features. First-line CLL/SLL patients had del17p and/or TP53 mutations. In this interim analysis, the median follow-up time for patients with CLL/SLL and MCL was 17.7 and 15.1 months, respectively. In the effectiveness populations for CLL/SLL (n = 200) and MCL (n = 59), the median progression-free survival was not estimable and 12.4 months, respectively; the 12-month overall survival rates were 88.5% and 65.8%, respectively. Treatment-emergent adverse events of interest for patients with CLL/SLL (n = 202) and MCL (n = 59) included: infections and infestations (53.5% and 32.2%), major bleeding (5.0% and 5.1%), and atrial fibrillation (5.9% and 8.5%); 135 (66.8%) and 20 (33.9%) patients were continuing treatment at the time of data cutoff. Future analyses will report on longer-term follow-up (Trial registration: ClinicalTrials.gov, NCT03425591. Registered 1 February 2018—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03425591).

Ibrutinib-Associated Cardiotoxicity: From the Pharmaceutical to the Clinical

Ibrutinib is the first-in-class Bruton tyrosine kinase (BTK) inhibitor that has revolutionized the treatment of B cell malignancies. Unfortunately, increased incidences of cardiotoxicity have limited its use. Despite over a decade of research, the biological mechanisms underlying ibrutinib cardiotoxicity remain unclear. In this review, we discuss the pharmacological properties of ibrutinib, the incidence and mechanisms of ibrutinib-induced cardiotoxicity, and practical management to prevent and treat this condition. We also synopsize and discuss the cardiovascular adverse effects related to other more selective BTK inhibitors, which may guide the selection of appropriate BTK inhibitors.

SOHO State of the Art Updates and Next Questions: Managing Relapsed Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a rare subtype of B-cell non-Hodgkin lymphoma i.e., incurable with current therapies. While some patients experience prolonged remissions following initial therapy, most will have a relapsing-remitting course requiring several lines of treatment over the course of their disease. Several targeted therapies are now available to treat patients with relapsed MCL. The Bruton's tyrosine kinase (BTK) inhibitors, including ibrutinib, acalabrutinib, and zanubrutinib, are highly active in MCL and currently approved for treating patients with relapsed disease. Bortezomib and lenalidomide are available as monotherapy or in combination with other agents. Venetoclax is active and can be considered for use in relapsed MCL, although it is not currently approved by regulatory agencies. Chimeric antigen receptor T-cell (CAR-T) therapy with brexucabtagene autoleucel yields high response rates and is now approved for patients with relapsed MCL. Allogeneic stem cell transplant remains an option for a small subset of medically fit and motivated patients who have progressed through multiple lines of therapy, although its use is limited by substantial toxicity. There is currently no standard approach to sequencing therapies for patients with relapsed MCL, and the ability to utilize disease biologic and clinical characteristics to guide treatment decisions in this setting remains limited. In this review, we summarize the current evidence to guide the management of patients with relapsed MCL, review emerging agents and combination therapies that are under investigation, and outline our current treatment approach for these patients.

Risk of bleeding associated with BTK inhibitor monotherapy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The risk of bleeding associated with Bruton's tyrosine kinase inhibitor (BTKi) monotherapy remains to be understood. This systematic review aims to evaluate BTKi monotherapy related bleeding risk.

RESEARCH DESIGN AND METHODS

PubMed, Embase, and CENTRAL were searched up to December 5, 2021. We included randomized controlled trials (RCTs) comparing BTKi monotherapy with control drugs or placebo, or comparing different BTKi monotherapies. The risk ratios (RR) with 95% confidence intervals (95% CI) were calculated.

RESULTS

10 studies with 3139 patients were included. Ibrutinib (vs. control drugs or placebo) significantly increased the risk of overall bleeding and major bleeding (RR=2.22, 95% CI 1.80-2.75, P<0.00001; RR=1.80, 95% CI 1.02-3.18, P=0.04, respectively). Acalabrutinib (vs. control drugs) had a significantly increased overall bleeding risk (RR=3.45, 95% CI 2.39-4.99, p<0.00001). A significant difference was found in overall bleeding between ibrutinib and acalabrutinib (RR=1.35, 95% CI 1.11-1.64, P=0.002). Compared to zanubrutinib, ibrutinib tended to increase the risk of major bleeding (RR=1.55, 95% CI 0.57-4.18, P=0.39).

CONCLUSIONS

Ibrutinib and acalabrutinib (vs. control drugs or placebo) have a higher risk of bleeding and overall bleeding, respectively. Limited evidence suggests that ibrutinib (vs. acalabrutinib) significantly increases overall bleeding risk, but the differences are not observed in other comparisons.

Mantle cell lymphoma negative for t(11,14) involving the kidneys: a case report

Background

Mantle cell lymphoma is the rarest subtype of non-Hodgkin’s lymphoma. It can exhibit diverse extranodal manifestations. However, renal involvement is uncommon, and if it occurs, it usually only gets detected postmortem. There are several mechanisms by which mantle cell lymphoma can damage the kidneys. Renal failure is a potential complication, and prompt evaluation and diagnosis are critical steps to prevent long-term complications.

Case presentation

We present the case of a 75-year-old non-Hispanic White male with past medical history significant for hypertension and dyslipidemia, presenting with fever, weight loss, and night sweats. Work-up showed markedly elevated white blood cells, multiple enlarged lymph nodes, and a kidney mass. The patient was diagnosed with mantle cell lymphoma with kidney involvement confirmed with a kidney biopsy. His disease was positive for cyclin D1 overexpression despite t(11; 14) absence. The patient received six cycles of alternating vincristine, rituximab, cyclophosphamide, doxorubicin, and prednisone then dexamethasone, high-dose cytarabine, and oxaliplatin, after which he was maintained on ibrutinib and rituximab, with resolution of symptoms and disease regression.

Conclusion

We present a case of a rare presentation of Mantle cell lymphoma while describing the clinical presentation and diagnostic and treatment approaches. This case report can assist physicians in the clinical work-up and treatment of patients with similar diagnosis or presentation.

Mantle Cell Lymphoma: the Role of Risk-Adapted Therapy and Treatment of Relapsed Disease

PURPOSE OF REVIEW

In this review, the current treatment strategies are recapped, evolving agents are discussed, and we provide guidance in treating R/R MCL.

RECENT FINDINGS

There has been an advancement in treatment using targeted therapy, cellular therapies including chimeric antigen receptor (CAR) T cell therapy and hematopoietic stem cell transplantation (HSCT) and novel therapeutic agents including non-covalent BTKis, bispecific antibodies, and antibody-drug conjugates for treatment of refractory and relapsed mantle cell lymphoma. Mantle cell lymphoma (MCL) is a mature B-cell lymphoma that is associated with a poor prognosis. Current treatments include immunochemotherapy, chemotherapy and autologous stem cell transplantation (SCT) which place patients in remission but result in relapse. Chemoimmunotherapy uses chemotherapeutic agents paired with rituximab in patients who have chemo-sensitive disease with prolonged remission of at least > 2 years and/or have contraindications to chemotherapy that serve as bridges to more definitive treatment. Additional therapies including proteosome inhibitor-based therapies and immunomodulators, like bortezomib and lenalidomide, can be used as single agents or in combination with others. Bruton's tyrosine kinase (BTK) inhibitors including ibrutinib, acalaburtinib, and zanubrutinib have also been proven effective for the treatment of (R/R) disease. Another agent is Venetoclax, a robust drug that can be used in MCL after progression or intolerance to BTKi. Newer advances in the management of MCL have led to the utilization of cellular therapies including chimeric antigen receptor (CAR) T cell therapy and SCT that are options for healthy young (< 65 years old) who have progressed through several lines of therapies. With progression of disease, mutations are acquired that cause therapy resistance. Novel therapeutic agents such as non-covalent BTKis, bispecific antibodies, and antibody-drug conjugates are paving the way for advancements in treatment for R/R MCL. R/R MCL is a complex disease with many therapeutic options none of which has been proven superior in head-to-head comparison. In this review, the current treatment strategies are recapped, evolving agents are discussed, and we provide guidance in treating R/R MCL.

New Directions for Mantle Cell Lymphoma in 2022

Mantle cell lymphoma is a rare B-cell non-Hodgkin lymphoma that is clinically and biologically heterogeneous. Risk stratification at the time of diagnosis is critical. One of the most powerful prognostic indices is the Mantle Cell Lymphoma International Prognostic Index-Combined, which integrates an estimate of proliferation (Ki67 index) with the standard Mantle Cell Lymphoma International Prognostic Index clinical factors. In addition, the presence of TP53 mutation is associated with suboptimal response to intensive chemoimmunotherapy and particularly dismal survival outcomes. Given their excellent activity in the relapsed/refractory setting, increasingly, biologically targeted therapeutics-such as covalent Bruton tyrosine kinase inhibitors, lenalidomide, and venetoclax-are being incorporated into "chemotherapy-free" regimens and in combination with established chemoimmunotherapy backbones for treatment-naïve mantle cell lymphoma. In addition, risk-adapted treatment programs are increasingly being studied. These programs tailor treatment according to baseline prognostic factors (e.g., presence of TP53 mutation) and may incorporate biomarkers of response such as minimal residual disease assessment. Although still investigational, these studies present an opportunity to move beyond the biology-agnostic, historical fitness-based treatment selection paradigm and toward a more personalized, tailored treatment approach in mantle cell lymphoma. After Bruton tyrosine kinase inhibitor failure, many promising standard or investigational therapies exist, including CAR T-cell therapy (including brexucabtagene autoleucel and lisocabtagene maraleucel), bispecific antibody therapy targeting CD20-CD3, zilovertamab vedotin (an antibody-drug conjugate that targets ROR1), and the noncovalent Bruton tyrosine kinase inhibitor pirtobrutinib. These new therapies show promising efficacy, even among high-risk patients, and will likely translate to improvements in survival outcomes for patients with progressive mantle cell lymphoma following treatment with a Bruton tyrosine kinase inhibitor.

Ibrutinib, Lenalidomide and Dexamethasone in Patients with Relapsed and/or Refractory Multiple Myeloma: Phase I Trial Results

Therapeutic strategies that target novel pathways are urgently needed for patients with relapsed/refractory multiple myeloma (RRMM). Ibrutinib is an oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in MM cells. This phase 1 dose-escalation study examined various doses of ibrutinib in combination with standard doses of lenalidomide (25mg) and dexamethasone (40mg) using a standard 3+3 design in RRMM patients. The primary objective was to determine the maximum tolerated dose (MTD) of ibrutinib in combination with lenalidomide and dexamethasone. Patients (n=15) had received a median of 4 prior regimens, 53% were triple-class exposed, 33% were penta-exposed, and 54% were lenalidomide-refractory. The MTD of ibrutinib was 840mg (n=6) and only 1 dose-limiting toxicity (DLT); a grade 3 rash possibly related to ibrutinib was noted. The most common ≥grade 3 adverse events (AEs) were rash in 2 (13%), lymphopenia in 2(13%), leukopenia, neutropenia, thrombocytopenia, and anemia all occurring in 3 (20%) patients each. One patient achieved a partial response for an overall response rate of 7%. The clinical benefit rate was 80%. The median time to progression was 3.8 months. Ibrutinib, lenalidomide and dexamethasone appears to be a safe and well-tolerated regimen with reasonable efficacy in heavily pretreated RRMM patients. This article is protected by copyright. All rights reserved.

Novel treatments in B cell non-Hodgkin's lymphomas

The improved understanding of lymphoma biology and recent advances in the field of cancer immunology have paved the way for the development of many effective small molecule inhibitors and immunotherapies in B cell non-Hodgkin's lymphomas. This article reviews novel treatments that have been approved recently by the US Food and Drug Administration and are now routinely used in clinical practice. It discusses their mechanisms of action, efficacy and safety, current therapeutic roles, and future directions in the treatment paradigm of different types of B cell non-Hodgkin's lymphoma. It also reviews other exciting novel treatments that are not yet approved but have unique mechanisms of action and have shown encouraging early results.

Ibrutinib in the Treatment of Solid Tumors: Current State of Knowledge and Future Directions

Bruton's Tyrosine Kinase (BTK) is considered crucial in the activation and survival of both physiological and malignant B-cells. In recent years, ibrutinib, an oral BTK inhibitor, became a breakthrough therapy for hematological malignancies, such as chronic lymphocytic. However, ibrutinib's feasibility might not end there. Several other kinases with established involvement with solid malignancies (i.e., EGFR, HER2) have been found to be inhibited by this agent. Recent discoveries indicate that BTK is a potential anti-solid tumor therapy target. Consequently, ibrutinib, a BTK-inhibitor, has been studied as a therapeutic option in solid malignancies. While most preclinical studies indicate ibrutinib to be an effective therapeutic option in some specific indications, such as NSCLC and breast cancer, clinical trials contradict these observations. Nevertheless, while ibrutinib failed as a monotherapy, it might become an interesting part of a multidrug regime: not only has a synergism between ibrutinib and other compounds, such as trametinib or dactolisib, been observed in vitro, but this BTK inhibitor has also been established as a radio- and chemosensitizer. This review aims to describe the milestones in translating BTK inhibitors to solid tumors in order to understand the future potential of this agent better.

Combining BTK inhibitors with BCL2 inhibitors for treating chronic lymphocytic leukemia and mantle cell lymphoma

The advent of BTK inhibitors has changed the treatment of patients with chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). The first-in-class BTK inhibitor ibrutinib has shown remarkable therapeutic effects and manageable toxicities in multiple clinical trials. The second-generation BTK inhibitors, including acalabrutinib and zanubrutinib, also show remarkable efficacies. However, using BTK inhibitors as monotherapies requires continuous treatment. Resistance to BTK inhibitors and severe side effects unavoidably occur during BTK inhibitor monotherapy, frequently resulting in treatment failure. The addition of the BCL2 inhibitor venetoclax to BTK inhibitor may improve the therapeutic effects and result in deeper responses, providing a potential fixed-duration treatment, especially for patients with CLL. In this review, by focusing on CLL and MCL, we discussed the rationale for the combinational use and summarized the current data on the combinations of BTK inhibitors and venetoclax in patients with CLL and MCL.

Bendamustine-EAM versus R-BEAM after high-dose cytarabine-based induction in newly diagnosed patients with mantle cell lymphoma, a LYSA retrospective study

Cytarabine-based immuno-chemotherapy followed by autologous stem cell transplantation (ASCT) consolidation is standard of care for fit patients with Mantle Cell Lymphoma (MCL). BEAM (Carmustine, Etoposide, Aracytine, Melphalan) is among the most frequently used conditioning regimen. Studies comparing BEAM with Bendamustine-EAM (BeEAM) have suggested that patients treated with BeEAM have a better progression-free survival (PFS). We performed a cross-study analysis to better evaluate BeEAM. Thirty-five patients from a retrospective study who received R-DHAP/BeEAM were compared to 245 patients from the LyMa trial (NCT00921414) who all received R-DHAP followed by R-BEAM. PFS and Overall Survival (OS) were estimated using Kaplan-Meier methods. At 2 years there was no difference between R-BEAM and BeEAM in either PFS (84.9% versus 87.9%; p = 0.95) or OS (91.8% versus 94.2%; p = 0.30). Analyses were repeated on a propensity score to reduce biases. Each patient from the BeEAM cohort (n = 30) was matched to three patients from the R-BEAM cohort (n = 90) for age, sex, MIPI score, pre-transplant status disease and rituximab maintenance (RM). PFS and OS at 2 years remained similar between R-BEAM and BeEAM with more renal toxicity in BeEAM group. MCL patients who received R-DHAP induction before ASCT have similar outcome after R-BEAM or BeEAM conditioning regimen.

Zanubrutinib in relapsed/refractory mantle cell lymphoma: long-term efficacy and safety results from a phase 2 study

Zanubrutinib demonstrated deep and durable responses and a favorable safety profile in R/R MCL at median 35.3 months follow-up.

Zanubrutinib provided a high response rate (84% [78% CR]) and extended PFS (median 33.0 months) in patients with R/R MCL.

Bruton tyrosine kinase (BTK) inhibitor is an established treatment for relapsed/refractory (R/R) mantle cell lymphoma (MCL). Zanubrutinib, a highly selective BTK inhibitor, is approved for patients with MCL who have received ≥1 prior therapy. We report the long-term safety and efficacy results from the multicenter, open-label, phase 2 registration trial of zanubrutinib. Patients (n = 86) received oral zanubrutinib 160 mg twice daily. The primary endpoint was the overall response rate (ORR), assessed per Lugano 2014. After a median follow-up of 35.3 months, the ORR was 83.7%, with 77.9% achieving complete response (CR); the median duration of response was not reached. Median progression-free survival (PFS) was 33.0 months (95% confidence interval [CI], 19.4-NE). The 36-month PFS and overall survival (OS) rates were 47.6% (95% CI, 36.2-58.1) and 74.8% (95% CI, 63.7-83.0), respectively. The safety profile was largely unchanged with extended follow-up. Most common (≥20%) all-grade adverse events (AEs) were neutrophil count decreased (46.5%), upper respiratory tract infection (38.4%), rash (36.0%), white blood cell count decreased (33.7%), and platelet count decreased (32.6%); most were grade 1/2 events. Most common (≥10%) grade ≥3 AEs were neutrophil count decreased (18.6%) and pneumonia (12.8%). Rates of infection, neutropenia, and bleeding were highest in the first 6 months of therapy and decreased thereafter. No cases of atrial fibrillation/flutter, grade ≥3 cardiac AEs, second primary malignancies, or tumor lysis syndrome were reported. After extended follow-up, zanubrutinib demonstrated durable responses and a favorable safety profile in R/R MCL. The trial is registered at ClinicalTrials.gov as NCT03206970.

Use of BTK inhibitors with focus on ibrutinib in mantle cell lymphoma: an expert panel opinion statement

The introduction of BTK inhibitors transformed the management of patients with mantle cell lymphoma (MCL). Ibrutinib, the first-in-class BTK inhibitor is now approved in more than 80 countries and there are over 20 new BTK inhibitors in development. In addition, novel agents show potential clinical activity (alone and in combination) and are in the approval phase and/or being studied in ongoing clinical trials. How does the practicing clinician decide on the optimal therapeutic strategy for this highly heterogenous disease? In July 2020 a group of experts from Italy, convened a meeting to address and provide clarification on a series of outstanding issues in the treatment of MCL with the view of providing clinical guidance on its management. This expert opinion statement represents the panel's collective analysis, evaluation, and recommendations and is made up of a series of questions and answers (in the form of a review of the pertinent literature) designed to replicate those posed by practicing clinicians in Italy but which are applicable to clinical settings worldwide. This article is protected by copyright. All rights reserved.

Determinants of Atrial Fibrillation Development among Patients undergoing Ibrutinib Therapy

Objective: Within the last decade, the use of ibrutinib, a first-generation, non-selective, irreversible Burton's tyrosine kinase inhibitor for the treatment of hematological malignancies has proven highly effective in improving patient outcomes.Background: Ibrutinib has been associated with an increase in atrial fibrillation (AF). The predisposing factors are thought to be pre-existing cardiovascular risk factors, but these have not been directly evaluated.Methods: We conducted a nested case-control study, recruiting consecutive ibrutinib treated subjects to evaluate cardiovascular risk factors associated with the development of AF in patients diagnosed with hematological B-cell malignancies.Results: Of the 189 patients treated with ibrutinib and without AF at baseline, 54 (29%) developed AF. Cardiovascular risk factors associated with AF development were, older age, prior hypertension (HTN), history of heart failure (HF) and congenital heart disease. A patient with HF at baseline had a 1, 2, 6, and 12 month cumulative hazard of AF of 40%, 48%, 64%, and 71%, respectively. Patients with prior HTN without HF at baseline had a 1, 2, 6, and 12 month cumulative hazard of AF of 5%, 10%, 23%, and 31%, respectively while on ibrutinib therapy.Conclusions: The relationship between ibrutinib, cardiovascular comorbidities, and AF is through pre-existing cardiovascular disease. An individualized, multidisciplinary approach involving cardiologists should be considered when initiating ibrutinib, particularly when there is a history of HTN, HF or congenital heart disease. In such patients, there should be close cardiovascular monitoring and prompt intervention when AF develops to improve patient outcomes.

Relapsed/Refractory Mantle Cell Lymphoma: Beyond BTK Inhibitors

Mantle cell lymphoma (MCL) is a rare mature B-cell non-Hodgkin lymphoma (B-NHL) with historically poor outcomes. Virtually all patients will eventually experience refractory or relapsed (R/R) disease, with a virulent course of resistance and serial relapses, making treatment challenging. The available therapies for R/R MCL are not curative with conventional therapy, their goal being to palliate and prolong survival. A variety of agents approved for R/R MCL, including Bruton's tyrosine kinase inhibitors (BTKi), changed the treatment landscape of R/R MCL. In the pre-BTKi era, the median progression-free survival (PFS) in R/R disease was 4-9 months. With the introduction of ibrutinib, the median PFS improved to 13-14.6 months. Despite these impressive results, the duration of response is limited, and resistance to BTKi inevitably develops in a subset of patients. Outcomes after progression on BTKi are extremely poor, with a median overall survival (OS) of 6 to 10 months. Certain therapies, such as chimeric antigen receptor (CAR) T cells, have shown promising results after BTKi failure. The preferred combination and sequencing of therapies beyond BTKi remain unestablished and are currently being investigated. In this review, we describe the current evidence for the available treatment of R/R MCL after progression on BTKi.

Chimeric antigen receptor (CAR) T-cell treatment for mantle cell lymphoma (MCL)

Mantle cell lymphoma (MCL) is a rare B-cell malignancy that remains challenging to treat with high rates of relapse. Frontline strategies range from intensive chemotherapy followed by consolidation with autologous stem cell transplant (ASCT), to less-intensive therapies including combination regimens. The treatment landscape for relapsed patients includes Bruton tyrosine kinase (BTK) inhibitors among other targeted treatments. Novel agents such as the selective BCL2 inhibitor venetoclax showed high response rates when used as monotherapy for refractory relapsed MCL. The rituximab, bendamustine, and cytarabine (R-BAC) regimen, while response rates were high, were not durable. Chimeric antigen receptor (CAR) T-cell products targeting CD19 have been efficacious in relapsed and refractory MCL patients. Brexucabtagene autoleucel (brexu-cel, formerly KTE-X19) was approved by US Food and Drug Administration (FDA) in July, 2020, for treatment of refractory and relapsed MCL. This article provides an overview for the available management strategies for relapsed MCL and examines the role of CAR T-cell in the current and future treatment of MCL.

Pooled safety analysis of zanubrutinib monotherapy in patients with B-cell malignancies

Zanubrutinib is a selective Bruton tyrosine kinase (BTK) inhibitor evaluated in multiple B-cell malignancy studies. We constructed a pooled safety analysis to better understand zanubrutinib-associated treatment-emergent adverse events (TEAEs) and identify treatment-limiting toxicities. Data were pooled from 6 studies (N = 779). Assessments included type, incidence, severity, and outcome of TEAEs. Median age was 65 years; 20% were ≥75 years old. Most patients had Waldenström macroglobulinemia (33%), chronic lymphocytic leukemia/small lymphocytic lymphoma (29%), or mantle-cell lymphoma (19%). Median treatment duration was 26 months (range, 0.1-65); 16% of patients were treated for ≥3 years. Common nonhematologic TEAEs were upper respiratory tract infection (URI, 39%), rash (27%), bruising (25%), musculoskeletal pain (24%), diarrhea (23%), cough (21%), pneumonia (21%), urinary tract infection (UTI), and fatigue (15% each). Most common grade ≥3 TEAEs were pneumonia (11%), hypertension (5%), URI, UTI, sepsis, diarrhea, and musculoskeletal pain (2% each). Atrial fibrillation and major hemorrhage occurred in 3% and 4% of patients, respectively. Atrial fibrillation, hypertension, and diarrhea occurred at lower rates than those reported historically for ibrutinib. Grade ≥3 adverse events included neutropenia (23%), thrombocytopenia (8%), and anemia (8%). Serious TEAEs included pneumonia (11%), sepsis (2%), and pyrexia (2%).Treatment discontinuations and dose reductions for adverse events occurred in 10% and 8% of patients, respectively. Thirty-nine patients (4%) had fatal TEAEs, including pneumonia (n = 9), sepsis (n = 4), unspecified cause (n = 4), and multiple organ dysfunction syndrome (n = 5). This analysis demonstrates that zanubrutinib is generally well tolerated with a safety profile consistent with known BTK inhibitor toxicities; these were manageable and mostly reversible.

Evolving frontline immunochemotherapy for mantle cell lymphoma and the impact on survival outcomes

Because there have been a dvances in frontline treatment for mantle cell lymphoma (MCL) over the last 2 decades, we sought to characterize the changes in frontline treatment patterns and their association with outcomes. Patients with newly diagnosed MCL from September 2002 through June 2015 were enrolled in a prospective cohort study, and clinical characteristics, treatment, and clinical outcomes were compared between patients diagnosed from 2002 to 2009 (Era 1) compared with 2010 to 2015 (Era 2). Patient age, sex, and simplified MCL International Prognostic Index (sMIPI) score were similar between the 2 groups. In patients age 65 years or younger, there was less use of rituximab plus hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (R-Hyper-CVAD) (16.1% vs 8.8%) but more use of rituximab plus maximum-strength cyclophosphamide, doxorubicin, vincristine, and prednisone (R-maxi-CHOP) alternating with rituximab plus high-dose cytarabine (R-HiDAC), also known as the Nordic regimen, and R-CHOP alternating with rituximab plus dexamethasone, high-dose cytarabine, and cisplatin (R-DHAP) (1.1% vs 26.4%) and less use of R-CHOP or R-CHOP-like regimens (64.5% vs 35.2%) but more use of R-bendamustine (0% vs 12.1%) in Era 2 (P < .001). These changes were associated with improved event-free survival (EFS; 5-year EFS, 34.3% vs 50.0%; P = .010) and overall survival (OS; 5-year OS, 68.8% vs 81.6%; P = .017) in Era 2. In patients older than age 65 years, there was less use of R-CHOP or R-CHOP-like therapy (39.0% vs 14.3%) and nonstandard systemic therapy (36.6% vs 13.0%) but more use of R-bendamustine (0% vs 49.4%). These changes were associated with a trend for improved EFS (5-year EFS, 25.4% vs 37.5%; P = .051) in Era 2. The shift from R-CHOP or R-CHOP-like regimens to R-bendamustine was associated with improved EFS (5-year EFS, 25.0% vs 44.6%; P = .008) in Era 2. Results from this prospective cohort study provide critical real-world evidence for improved outcomes with evolving frontline patterns of care in patients with MCL.

Mantle cell lymphoma treatment options for elderly/unfit patients: A systematic review

Mantle cell lymphoma (MCL) is a rare B-cell non-Hodgkin lymphoma (NHL) that is aggressive and incurable with existing therapies, presenting a significant unmet clinical need. MCL occurs mainly in elderly patients with comorbidities; thus, intense treatment options including allogeneic stem cell transplantation (Allo-SCT) are not feasible. New treatment options are emerging for this elderly/unfit treatment group, we therefore conducted a systematic review to determine whether they offered an advance on the existing recommended treatment, R-CHOP. The search strategies to identify MCL therapies were designed to capture the most relevant studies from 2013 to 2020. Following preferred reporting items for systematic reviews and meta-analyses and population,interventions, observations and study design analysis, R-CHOP, ibrutinib and bendamustine plus rituximab (BR) were taken forward for critical and statistical analysis. All three therapies were effective in increasing the overall survival (OS) and progression-free survival of elderly/unfit patients with MCL. However, none resulted in a significant increase in OS compared to R-CHOP. In addition, R-CHOP had a better toxicity profile when compared to both ibrutinib and BR. We therefore conclude that treatment of elderly/unfit patients with MCL is still a significant unmet clinical need; and suggest that outside of the clinical trial setting, R-CHOP should remain the recommended front-line treatment for this patient group.

Initial Treatment Patterns and Survival Outcomes of Mantle Cell Lymphoma Patients Managed at Chinese Academic Centers in the Rituximab Era: A Real-World Study

Purpose

The aim of the study was to delineate the disease characteristics, the initial treatment patterns, and survival in patients with mantle cell lymphoma (MCL) managed in the real world.

Methods

Data of 518 MCL patients from 5 major Chinese Hematology Centers in the period from 2007 to 2017 were retrospectively analyzed.

Results

The median age was 58 years. Of the patients, 88.6% had Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0–1 and 80.7% had advanced-stage disease. Ki67 expression was <30% in 39.6% of the patients, and 43.2% of patients were categorized into a low-risk group based on the Mantle Cell Lymphoma International Prognostic Index (MIPI) scoring system. Overall, 73.4% of the patients received rituximab as their first-line therapy. The most commonly used chemotherapy was the CHOP-like (cyclophosphamide, hydroxydaunomycin, oncovin, and prednisone) regimen (45.2%), followed by high-dose cytarabine-containing chemotherapy (31.3%) and bendamustine (3.3%). Of the patients, 13.7% (n = 71) underwent consolidative autologous stem cell transplantation (ASCT), and 19.3% (n = 100) received novel agents containing first-line regimens. With a median follow-up time of 52 months, the 3- and 5-year overall survival (OS) rates were 73.7% and 61.4%, respectively. Age ≤60 years, ECOG PS 0–1, stages I–II, normal lactate dehydrogenase (LDH), absence of bone marrow involvement, Ki67 <30%, and lower-risk IPI/MIPI scores were significantly associated with improved OS (p < 0.05). The inclusion of rituximab improved the 5-year OS, with borderline significance (62.5% vs. 55.2%, p = 0.076). High-dose cytarabine-containing chemotherapy showed significant clinical benefit in 5-year OS (72.1% vs. 55.9%, p = 0.010). Patients with ASCT had better 5-year OS in the younger (≤60 years) age group (87.2% vs. 64.8%, p = 0.002).

Conclusion

This large retrospective dataset unequivocally confirmed the survival advantage afforded by cytarabine-containing regimen and ASCT in a first-line setting under real-world management in the rituximab era.

A phase-II study of atezolizumab in combination with obinutuzumab or rituximab for relapsed or refractory mantle cell or marginal zone lymphoma or Waldenström's macroglobulinemia

We report efficacy, safety and biomarker data from a phase-II study evaluating atezolizumab (eight 21-day cycle as induction therapy) in combination with obinutuzumab in patients with relapsed/refractory mantle cell lymphoma (MCL, n = 30) or Waldenström's macroglobulinemia (WM, n = 4), and in combination with rituximab in patients with marginal zone lymphoma (MZL, n = 21). All patients received atezolizumab monotherapy as maintenance for ≤10 cycles. Objective response rates at end of induction were 16.7% (MCL) and 42.9% (MZL), with no responses in WM. Median duration of response was 6.8 months (range 5.7-not estimable) for MCL and not reached for MZL. Treatment-emergent adverse events (TEAEs) occurred in 93.3%, 95.2% and 100% of MCL, MZL and WM patients, respectively. One fatal TEAE (pneumonia) occurred in each of the MCL and MZL groups. Biomarker analysis highlighted the importance of characterizing the immune environment to optimize efficacy of immunotherapy regimens.Trial registration details: EudraCT: 2016-003579-22.

Combinatorial inhibition of BTK, PI3K-AKT and BRD4-MYC as a strategy for treatment of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a subtype of non-Hodgkin's lymphoma characterized by poor prognosis. The complexity of MCL pathogenesis arises from aberrant activities of diverse signaling pathways, including BTK, PI3K-AKT-mTOR and MYC-BRD4. Here, we report that MCL-related signaling pathways can be altered by a single small molecule inhibitor, SRX3305. Binding and kinase activities along with resonance changes in NMR experiments reveal that SRX3305 targets both bromodomains of BRD4 and is highly potent in inhibition of the PI3K isoforms α, γ and δ, as well as BTK and the drug-resistant BTK mutant. Preclinical investigations herein reveal that SRX3305 perturbs the cell cycle, promotes apoptosis in MCL cell lines and shows dose dependent anti-proliferative activity in both MCL and drug-resistant MCL cells. Our findings underscore the effectiveness of novel multi-action small molecule inhibitors for potential treatment of MCL.

Bruton Tyrosine Kinase Inhibitors in B-Cell Malignancies: Their Use and Differential Features

Starting with the first-in-class agent ibrutinib, the development of Bruton tyrosine kinase (BTK) inhibitors has led to dramatic improvements in the management of B-cell malignancies. Subsequently, more-highly selective second-generation BTK inhibitors (including acalabrutinib, zanubrutinib, tirabrutinib and orelabrutinib) have been developed, primarily with an aim to reduce off-target toxicities. More recently, third-generation agents including the non-covalent BTK inhibitors pirtobrutinib and nemtabrutinib have entered later-stage clinical development. BTK inhibitors have shown strong activity in a range of B-cell malignancies, including chronic lymphocytic leukaemia/small lymphocytic lymphoma, mantle cell lymphoma, Waldenström's macroglobulinaemia and marginal zone lymphoma. The agents have acceptable tolerability, with adverse events generally being manageable with dosage modification. This review article summarises the evidence supporting the role of BTK inhibitors in the management of B-cell malignancies, including highlighting some differential features between agents.

Invasive Fungal Infections and Targeted Therapies in Hematological Malignancies

The use of targeted biologic therapies for hematological malignancies has greatly expanded in recent years. These agents act upon specific molecular pathways in order to target malignant cells but frequently have broader effects involving both innate and adaptive immunity. Patients with hematological malignancies have unique risk factors for infection, including immune dysregulation related to their underlying disease and sequelae of prior treatment regimens. Determining the individual risk of infection related to any novel agent is challenging in this setting. Invasive fungal infections (IFIs) represent one of the most morbid infectious complications observed in hematological malignancy. In recent years, growing evidence suggests that certain small molecule inhibitors, such as BTK inhibitors and PI3K inhibitors, may cause an increased risk of IFI in certain patients. It is imperative to better understand the impact that novel targeted therapies might have on the development of IFIs in this high-risk patient population.