Prolonged Responses in Central Nervous System Relapsed Diffuse Large B-Cell Lymphoma After Chimeric Antigen Receptor T-Cell Therapy Using Targeted Treatments.

The introduction of chimeric antigen receptor T-cell (CAR-T cell) therapy has changed the treatment landscape of diffuse large B-cell lymphoma (DLBCL). However, the optimal treatment strategy after relapse after this therapy still needs to be elucidated. In this report, we describe the case of a 67-year-old male who relapsed after treatment with tisagenlecleucel as a third-line therapy. We present our approach to treatment after relapse, in which we tried to sustain the circulating chimeric antigen receptor T-cells. This is reflected by the kinetics of the chimeric antigen receptor T-cells during these treatments.

Successful treatment of hemophagocytic intravascular large B-cell lymphoma with CNS involvement with BTK inhibitor combined with rituximab and high-dose methotrexate.

This is a case of hemophagocytic intravascular large B-cell lymphoma (IVLBCL) with central nervous system (CNS) involvement. Although R-CHOP chemotherapy regimen has been shown significant improvement in survival rate. The prognosis and outcomes remain unsatisfactory, which is identified as outstanding challenges and need solutions. Gene and molecular profiling studies may provide new therapeutic strategies, especially the BCR/TLR/IL-1R/NF-κB signaling pathway in IVLBCL. Here, we treated the hemophagocytic IVLBCL CNS-involved patient with the Bruton tyrosine kinase inhibitor (BTKi) to block NF-κB pathway, and indicated that the second-generation BTKi zanubrutinib-based treatment was feasible and efficient.

BTK inhibitors: past, present, and future.

Bruton's tyrosine kinase (BTK) inhibitors have revolutionized the treatment landscape for B cell lymphomas such as chronic lymphocytic leukemia (CLL). The first-in-class BTK inhibitor ibrutinib has recently been succeeded by covalent BTK inhibitors that are safer but still face challenges of resistance mutations. The noncovalent BTK inhibitor pirtobrutinib was recently approved for relapsed and refractory CLL, and whether noncovalent BTK inhibitors will supplant covalent BTK inhibitors as upfront treatment options either alone or in combination will be determined. Meanwhile, newer BTK inhibitors and BTK degraders are vying for their place in the potential future landscape of B cell cancers as well as autoimmune diseases. This review will cover the latest progress in BTK inhibitor development and where the field is moving in light of these recent discoveries.

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.

Covalent Bruton's Tyrosine Kinase Inhibitors in Chronic Lymphocytic Leukemia.

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

Brentuximab Vedotin Plus Ibrutinib in Relapsed and Refractory Hodgkin Lymphoma.

INTRODUCTION: Brentuximab vedotin (BV) is an antibody-drug conjugate that delivers monomethyl auristatin E (MMAE) to CD30+ cells and is safe and effective in relapsed/refractory (r/r) Hodgkin lymphoma (HL). Although most patients respond to BV, only a minority will obtain a complete response (CR), and almost all patients eventually progress. Ibrutinib is a Bruton's tyrosine kinase (BTK) inhibitor highly active in multiple subtypes of non-Hodgkin lymphoma; limited data exist regarding its use in HL. It irreversibly inhibits interleukin-2-inducible kinase (ITK) with Th1 based immune responses. As we previously observed preclinical synergy between ibrutinib and BV, we hypothesized ibrutinib may enhance the antitumor activity of BV in HL. We designed and conducted a phase II trial of ibrutinib plus BV in patients with R/R HL, and herein report the final primary analysis of safety and efficacy. METHODS: This was a multicenter phase II trial with a lead-in cohort in patients with r/r HL. Eligibility criteria included age ≥ 15 years with r/r HL after at least one prior line of therapy. Treatment consisted of 1.8 mg/kg BV intravenously every 3 weeks and ibrutinib 560 mg PO daily (420 mg PO daily in the lead-in cohort). Prior BV was allowed if patients were not refractory. The primary endpoint was the CR rate according to Lugano 2014. Secondary endpoints included toxicities, overall response rate (ORR), and duration of response (DOR). RESULTS: The 39 patients were enrolled onto the study, of which 67% were male; the median age was 33 (range: 17-71). 38% had extranodal disease at baseline, 51% had advanced stage disease, 51% were refractory to the prior therapy, and 21% had prior BV. Of 36 patients who were evaluable for response, the CR rate was 33% and ORR 64%; median DOR was 25.5 months. Thirteen patients proceeded to autologous transplant and 3 patients proceeded to allogeneic transplant for consolidation after response. The most common adverse events were nausea (67%), peripheral neuropathy (62%), diarrhea (59%), fatigue (46%), thrombocytopenia (46%), headache (41%), rash (41%), elevated ALT (38%), anemia (36%), vomiting (36%), abdominal pain (33%), fever (33%), and hypertension (33%). Six patients experienced unacceptable toxicity, defined as Gr 3/4 non-hematologic toxicity or non-resolving Gr 3/4 hematologic toxicity including one patient who died of multiorgan failure from suspected COVID-19 infection during cycle 1. DISCUSSION: The combination of BV and ibrutinib was active in r/r HL; however, given significant toxicity, it cannot be recommended for future development.

Targeted Therapies in the Treatment of Mantle Cell Lymphoma.

Mantle cell lymphoma (MCL) is a rare, heterogeneous B-cell non-Hodgkin's lymphoma. The standard front-line treatment utilizes chemotherapy, often followed by consolidation with an autologous hematopoietic cell transplant; however, in most patients, the lymphoma will recur and require subsequent treatments. Additionally, mantle cell lymphoma primarily affects older patients and is frequently chemotherapy-resistant, which has further fostered the necessity for new, chemotherapy-free treatment options. In the past decade, targeted therapies in mantle cell lymphoma have been practice-changing as the treatment paradigm shifts further away from relying primarily on cytotoxic agents. Here, we will review the pathophysiology of mantle cell lymphoma and discuss the emergence of targeted, chemotherapy-free treatments aimed at disrupting the abnormal biology driving its lymphomagenesis. Treatments targeting the constitutive activation of NF-kB, Bruton's Tyrosine Kinase signaling, and anti-apoptosis will be the primary focus as we discuss their clinical data and toxicities. Our review will also focus primarily on the emergence and use of targeted therapies in the relapsed/refractory setting but will also discuss the emergence of their use in front-line therapy and in combination with other agents.

Taking the Next Step in Double Refractory Disease: Current and Future Treatment Strategies for Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is a monoclonal B-cell lymphoproliferative disease with a high annual incidence in Western countries. As B-cell receptor (BCR) signaling and intrinsic apoptotic resistance play critical roles in the development and survival of CLL cells, therapeutic approaches targeting these pathways have been extensively investigated to tackle this incurable disease. Over the last decade, several Phase 3 trials have confirmed the superior efficacy of covalent Bruton tyrosine kinase inhibitors (cBTKis) and venetoclax, a selective B-cell lymphoma 2 (BCL2) inhibitor, over chemoimmunotherapy. This has been demonstrated in both the treatment-naïve and relapsed/refractory (RR) settings and includes patients with high-risk molecular features. However, these drugs are not curative, with patients continuing to relapse after treatment with both cBTKis and BCL2is, and the optimal treatment strategy for these patients has not been defined. Several novel agents with distinct mechanisms have recently been developed for CLL which have demonstrated efficacy in patients who have previously received cBTKis and BCL2i. In particular, novel BCR-signaling targeting agents have shown promising efficacy in early-phase clinical trials for RR-CLL. Furthermore, cancer immunotherapies such as bispecific antibodies and chimeric antigen receptor T-cells have also shown anti-tumor activity in patients with heavily pretreated RR-CLL. Personalised approaches with these novel agents and combination strategies based on the understanding of resistance mechanisms have the potential to overcome the clinical challenge of what to do next for a patient who has already had a cBTKi and venetoclax.

Modified R-BAC plus BTK inhibitor regimen in newly diagnosed young patients with mantle cell lymphoma: a real-world retrospective study.

To explore the optimal treatment for young patients with untreated mantle cell lymphoma (MCL), we compared the efficacy and safety of R-CHOP/R-DHAP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone/rituximab, dexamethasone, cytarabine and cisplatin) and R-BAP (rituximab, bendamustine, cytarabine, and prednisone) plus BTK (Bruton's tyrosine kinase) inhibitors in newly diagnosed patients. Eighty-three young patients (≤ 65 years old) with newly diagnosed MCL admitted to the First Affiliated Hospital of Zhengzhou University from January 1, 2014, to June 1, 2023, using R-CHOP/R-DHAP or R-BAP plus BTK inhibitor were assessed in this study. The median age at presentation was 60 (42-65) years in 83 patients, including 64 males and 19 females; 59 were treated with R-CHOP/R-DHAP regimen chemotherapy, and 24 were treated with R-BAP in combination with the BTK inhibitor regimen. The median follow-up was 17 months (2-86 months) in 83 patients, and the median PFS (progression-free survival) time was not reached. The CRR (complete response rate) of the R-BAP group was higher than that of the R-CHOP/R-DHAP group (87.5% vs. 54.2%, P = 0.005). The ORR (overall response rate) was not significantly different between the two groups (ORR: 91.7% vs. 84.7%, P = 0.497). The PFS (progression-free survival) of the R-BAP group was longer than that of the R-CHOP/R-DHAP group (P = 0.013), whereas OS was not significantly different between the two groups (P = 0.499). The most common adverse effect in both groups was hematotoxicity, with a higher incidence of grade 3-4 lymphopenia and grade 3-4 thrombocytopenia in the R-BAP group than in the R-CHOP/R-DHAP group (P = 0.015 and P = 0.039). Male sex (HR = 4.257, P = 0.013), LDH (lactate dehydrogenase) ≥ 245 U/L (HR = 3.221, P = 0.012), pleomorphic-blastoid (HR = 2.802, P = 0.043) and R-CHOP/R-DHAP regimen (HR = 7.704, P = 0.047) were independent risk factors for PFS. Ki67 ≥ 30% (HR = 8.539, P = 0.005) was an independent risk factor for OS. First-line treatment with R-BAP in combination with BTK inhibitor improved CRR and prolonged PFS in young patients with mantle cell lymphoma and adverse events were tolerable.

[Efficacy and Prognosis of Chemotherapy Regimen Containing BTK Inhibitor in Treatment of Recurrent/Refractory Mantle Cell Lymphoma].

OBJECTIVE: To investigate the efficacy and prognosis of chemotherapy regimen containing Bruton's tyrosine kinase (BTK) inhibitor in the treatment of relapsed/refractory mantle cell lymphoma (R/R MCL). METHODS: The clinical data of 134 patients with R/R MCL were collected and analyzed retrospectively. The clinical characteristics of patients and effect of chemotherapy regimen on efficacy, overall survival (OS) and progression-free survival (PFS) were observed. RESULTS: The median age of the patients was 58(56-61) years old, and male to female ratio was about 2.9∶1. Patients with Ann Arbor stage III-IV accounted for 77.6%, extranodal involvement > 2 for 43.3%, bone marrow involvement for 60.4%, gastrointestinal involvement for 24.6%, and hepatosplenomegaly for 38.1%. The median follow-up time was 30 (2-103) months, overall response rate (ORR) was 41.8%, 3-year PFS was not reached, and 3-year and 5-year OS rate was 62.7% and 53.8%, respectively. The ORR of BTK inhibitor group was 56.9%, which was higher than 32.5% of non-BTK inhibitor group (P =0.006). The difference was statistically significant in PFS between the two groups (P =0.002), but was not in OS (P>0.05). The difference was statistically significant in OS between classical and special morphology (P < 0.001), but was not in PFS (P >0.05). Ki-67 was an influencing factor for OS and PFS. Multivariate analysis showed that Ki-67, B symptoms, MIPI score, and Ann Arbor stage were independent prognostic factors affecting patients' OS. The second-line treatment regimen was an independent prognostic factor affecting patients' PFS. CONCLUSIONS: The chemotherapy regimen containing BTK inhibitors can effectively improve the efficacy and prolong the PFS of R/R MCL patients. Ki-67, B symptoms, MIPI score, and Ann Arbor stage are independent prognostic factors for R/R MCL patients.

The Pharmacokinetic Interaction of Tirabrutinib with Voriconazole, Itraconazole, and Fluconazole in SD Rats by UPLC-MS/MS.

BACKGROUND: Tirabrutinib is an orally effective, approved, and highly selective second-generation Bruton's tyrosine kinase (BTK) inhibitor for the treatment of recurrent or refractory primary central nervous system lymphoma (PCNSL). OBJECTIVE: This study aimed to develop an ultra-high performance liquid chromatography- tandem mass spectrometry (UPLC-MS/MS) method for the determination of tirabrutinib concentration in rat plasma, where zanubrutinib was used as an internal standard (IS). This method was also applied to study whether tirabrutinib would interact with voriconazole, itraconazole, and fluconazole in rats, providing a reference value for clinical medication guidance. METHODS: In the current study, the organic solvent protein precipitation method was used to treat plasma samples, which is simple and reproducible. Tirabrutinib (m/z 455.32 → 320.21) and zanubrutinib (m/z 472.13 → 455.04) were separated on a Waters Acquity BEH C18 column (2.1 × 50 mm, 1.7 µm) and detected by multiple reaction monitoring (MRM) in positive ionization mode. RESULTS: The method showed good linearity in the range of 5-3000 ng/mL for tirabrutinib with the lower limit of quantification (LLOQ) of 5 ng/mL. The recovery and matrix effects were 85.7-91.0% and 102.0-113.3%, respectively. The accuracy, precision, stability, and carry-over effect were also acceptable. The method could also be used for determining the pharmacokinetic interaction of tirabrutinib in rats. The results showed AUC0→∞ of tirabrutinib to be increased by 139.3% and 83.9% in the presence of voriconazole and fluconazole, respectively, while itraconazole had little effect. CONCLUSION: It is necessary to monitor the concentration of tirabrutinib in patients when it is combined with voriconazole and fluconazole to achieve a better therapeutic effect and reduce the risk of adverse reaction. Further research should be conducted in the future.

Recent advances in genomics and therapeutics in mantle cell lymphoma.

Over the past decades, significant strides have been made in understanding the pathobiology, prognosis, and treatment options for mantle cell lymphoma (MCL). The heterogeneity observed in MCL's biology, genomics, and clinical manifestations, including indolent and aggressive forms, is intricately linked to factors such as the mutational status of the variable region of the immunoglobulin heavy chain gene, epigenetic profiling, and Sox11 expression. Several intriguing subtypes of MCL, such as Cyclin D1-negative MCL, in situ mantle cell neoplasm, CCND1/IGH FISH-negative MCL, and the impact of karyotypic complexity on prognosis, have been explored. Notably, recent immunochemotherapy regimens have yielded long-lasting remissions in select patients. The therapeutic landscape for MCL is continuously evolving, with a shift towards nonchemotherapeutic agents like ibrutinib, acalabrutinib, and venetoclax. The introduction of BTK inhibitors has brought about a transformative change in MCL treatment. Nevertheless, the challenge of resistance to BTK inhibitors persists, prompting ongoing efforts to discover strategies for overcoming this resistance. These strategies encompass non-covalent BTK inhibitors, immunomodulatory agents, BCL2 inhibitors, and CAR-T cell therapy, either as standalone treatments or in combination regimens. Furthermore, developing novel drugs holds promise for further improving the survival of patients with relapsed or refractory MCL. In this comprehensive review, we methodically encapsulate MCL's clinical and pathological attributes and the factors influencing prognosis. We also undertake an in-depth examination of stratified treatment alternatives. We investigate conceivable resistance mechanisms in MCL from a genetic standpoint and offer precise insights into various therapeutic approaches for relapsed or refractory MCL.

Bruton's Tyrosine Kinase Inhibitors for Multiple Sclerosis Treatment: A New Frontier.

Multiple sclerosis (MS) can cause significant disability to patients via relapse-associated worsening and progression independent of relapses. The causes of neuronal and myelin damage can include lymphocyte-mediated inflammation and microglial activation. Bruton's tyrosine kinase (BTK) is an enzyme that mediates B cell activation and the proinflammatory phenotype of microglia. Inhibiting BTK provides a novel therapeutic target for MS but also has a complicated pharmacology based on binding specificity, CNS penetration, half-life, and enzyme inhibition characteristics. Multiple agents are being studied in phase 3 trials, and each agent will have unique efficacy and safety profiles that must be considered individually.

[Research Progress in Treatment of Chronic Lymphocytic Leukemia --Review].

Chronic lymphocytic leukemia (CLL) is a low-grade lymphoproliferative tumor that occurs frequently in middle-aged and elderly people. Early and precise intervention can effectively improve the clinical prognosis of CLL patients. In the past, chemotherapy was the main treatment plan. With the development of molecular biology and the continuous advent of immune targeting drugs, targeted drugs targeting B cell receptor signaling pathway have shown high clinical application value in the diagnosis and treatment path of CLL. Cellular immunotherapies such as CAR-T also offer hope for patients with relapsed and refractory CLL. Allogeneic hematopoietic stem cell transplantation and multi-drug combination have also shown remarkable results in clinical practice. The purpose of this article is to review the latest research progress in the treatment of CLL.

Bruton's tyrosine kinase is a possible therapeutic target in microscopic polyangiitis.

BACKGROUND: Bruton's tyrosine kinase (Btk) is an enzyme expressed in leukocytes other than T lymphocytes and plasma cells and involved in B-cell receptor- and Fcγ receptor (FcγR)-mediated signal transduction. Btk inhibitors potentially suppress autoantibody production due to the expected inhibitory ability of B lymphocyte differentiation into antibody-producing plasma cells and reduce FcγR-mediated neutrophil activation, including the release of neutrophil extracellular traps (NETs). Microscopic polyangiitis (MPA) is a systemic small-vessel vasculitis characterized by the pathogenic autoantibody, antineutrophil cytoplasmic antibody (ANCA) that reacts with myeloperoxidase (MPO). MPO and MPO-ANCA immune complex (IC)-induced FcγR-mediated NETs are critically involved in MPA pathogenesis. This study aimed to demonstrate the therapeutic efficacy of the Btk inhibitor tirabrutinib on MPA. METHODS: Various doses of tirabrutinib or vehicle were orally administered to Sprague-Dawley rats daily. Four weeks later, the number of peripheral B lymphocytes was counted, and Btk phosphorylation in B lymphocytes was evaluated by flow cytometry. Human peripheral blood neutrophils were stimulated by MPO and anti-MPO antibody ICs (MPO and anti-MPO-ICs), and Btk and its downstream Vav phosphorylation were assessed by western blotting. The effects of tirabrutinib on MPO and anti-MPO-IC-induced NET formation were examined in vitro. Wistar Kyoto rats were immunized with human MPO to induce experimental MPA and given drug-free or tirabrutinib-containing feed (0.0037% or 0.012%) from day 0 or 28. All rats were euthanized on day 42 for serological and histological evaluation. RESULTS: Tirabrutinib inhibited Btk phosphorylation without decreasing B lymphocytes in vivo. Neutrophil Btk and Vav were phosphorylated when stimulated with MPO and anti-MPO-ICs. Tirabrutinib suppressed MPO and anti-MPO-IC-induced NET formation in vitro and ameliorated experimental MPA in a dose-dependent manner in vivo. Although MPO-ANCA production was not affected, NET-forming neutrophils in the blood were significantly reduced by tirabrutinib. CONCLUSIONS: The Btk inhibitor tirabrutinib suppressed MPO and anti-MPO-IC-induced NET formation in vitro and ameliorated experimental MPA by reducing NET-forming neutrophils but not decreasing MPO-ANCA titer in vivo. This study suggests that Btk is a possible therapeutic target in MPA.

Advances in Treatment of Waldenström Macroglobulinemia.

PURPOSE OF REVIEW: The discovery of recurring somatic mutations, in particular MYD88 and CXCR4 mutations, in Waldenström macroglobulinemia (WM), a rare B-cell lymphoproliferative disorder, led in the last decade to the development of several therapeutic agents with high efficacy. This review aims to provide an overview of available treatments in WM and novel agents, focusing on studies published over recent years. RECENT FINDINGS: There is no international consensus on the best first-line option in treatment-naïve patients. Randomized clinical trials are rare in WM and there has been no prospective comparison of chemoimmunotherapy and BTK inhibitors in the frontline setting. Chemoimmunotherapy and BTK inhibitors, the two feasible and most widely used treatments in first-line treatment, represent very different options in terms of duration of therapy, route of administration, cost, and adverse effect. In addition to tumor genotype and patient comorbidities, choice of therapy in WM should take into account these parameters. Results of ongoing and future clinical trials evaluating fixed-duration combinations with BTK inhibitors and novel agents are awaited.

Combined analysis of the impact of second-generation BTK inhibitors on patient outcomes.

BTK inhibitors (BTKi) are highly effective in B-cell malignancies. Acalabrutinib and zanubrutinib have exhibited favorable safety profiles when compared with ibrutinib. We identified all published/presented randomized trials comparing a second-generation BTKi with ibrutinib and reconstructed individual patient-level, censored time-to-event data for adverse events to evaluate the impact of second-generation BTKi on safety outcomes including atrial fibrillation/flutter [AF], hypertension, bleeding, diarrhea, and infection. 1386 pts from ELEVATE-RR (n = 533), ALPINE (n = 652), and ASPEN (n = 201) trials were included in the analyses. Acalabrutinib or zanubrutinib were associated with significant reductions in cumulative event rates of AF (HR 0.28, 95% CI 0.18-0.42, p < 0.001), bleeding (HR 0.65, 95% CI 0.52-0.81, p < 0.001), diarrhea (HR 0.61, 95% CI 0.47-0.78, p < 0.001), hypertension (HR 0.40, 95% CI 0.27-0.61, p < 0.001), and infections (HR 0.83, 95% CI 0.70-0.98, p = 0.032). In summary, zanubrutinib and acalabrutinib have a favorable safety profile among pts with r/r B-cell malignancies. These data support use of acalabrutinib or zanubrutinib as preferred BTK inhibitors for approved indications.

The shifting therapeutic paradigm for relapsed/refractory mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a heterogeneous subtype of non-Hodgkin lymphoma that has been historically associated with poor 5-year overall survival rates, especially for aggressive variants. Traditional cytotoxic chemotherapy had been a mainstay of therapy for relapsed/refractory (R/R) MCL for many years until the advent of molecularly targeted therapies and cell-based approaches. However, a significant concern is the lack of definitive consensus guidelines for management of R/R MCL. The managerial conundrum partly stems from the absence of head-to-head comparisons of novel therapies, with conclusions drawn from cross-trial comparisons. In this evidence-based review, we discuss the current therapeutic options for R/R MCL, including the most recent data from the BRUIN study that led to the approval of the first-in-class non-covalent reversible Bruton's tyrosine kinase (BTK) inhibitor pirtobrutinib in 2023, as well as the recent removal of ibrutinib from the market. We discuss outlooks for targeted therapy and tolerability considerations for novel agents, including unique considerations for the elderly population. We highlight emerging data that support the curative potential of chimeric antigen receptor-T (CAR-T) therapy from ZUMA-2, relative to other promising investigational agents in the pipeline, including glofitamab, epcoritamab, and zilovertamab vedotin. We summarize management recommendations based upon the most rigorous clinical evidence to date.