Primary therapy of Waldenström macroglobulinemia with bortezomib, dexamethasone, and rituximab: WMCTG clinical trial 05-180

Novel Approaches to Managing Patients with Relapsed and Refractory Waldenström Macroglobulinemia

PURPOSE OF REVIEW

Waldenström macroglobulinemia is a rare non-Hodgkin lymphoma (NHL) characterized by lymphoplasmacytic bone marrow infiltration associated with an immunoglobulin M (IgM) monoclonal gammopathy. Over the past two decades, a number of important novel therapies have emerged for the treatment of relapsed and refractory (R/R) WM. The purpose of this review is to discuss these novel agents.

RECENT FINDINGS

Chemoimmunotherapy which formed the basis treatment for R/R WM is slowly being replaced by novel targeted agents. These therapies, including Bruton's tyrosine kinase inhibitors, proteasome inhibitors, and B-cell lymphoma 2 inhibitors, have widened the landscape of management. Emerging therapies currently under investigation, such as bispecific T-cell engagers, chimeric antigen T-cell receptor therapy, and novel small molecule inhibitors, have additionally shown the potential to improve response and survival. The treatment of R/R WM has greatly evolved, in large part due to a greater understanding of the biology of WM, and the evaluation of novel targeted agents in the basket trials of NHL, showing early activity in the small WM cohorts. Combination regimens with these established and emerging novel therapies have the potential to further improve disease control and induce higher rates of deep responses. Strategies aimed at altering the disease trajectory would require randomized controlled trials to provide relevant data on optimal integration and sequencing of more effective and tolerable regimens earlier in the disease course.

Efficacy and safety of therapeutic procedure for Waldenström's macroglobulinemia with hyperviscosity syndrome

INTRODUCTION

Hyperviscosity syndrome (HVS) is a significant complication in Waldenström's macroglobulinemia (WM), although the significance of plasmapheresis in clinical practice has not been clarified. To confirm the efficacy and safety of plasmapheresis followed by primary therapy for WM with HVS, we retrospectively conducted this study.

METHODS

Untreated WM with HVS, or serum immunoglobulin M (IgM) levels ≥4000 mg/dL, were analyzed. The basic therapeutic flow was conducted as follows: (1) performing plasmapheresis, (2) followed by primary therapy without rituximab, and (3) performing the second cycle. The serum IgM reduction rate and adverse events (AEs) were evaluated.

RESULTS

Ten patients were enrolled. The median serum IgM levels at diagnosis, post-plasmapheresis, after the first cycle of primary therapy, and after the second cycle were 5174, 2900, 3286, and 2657 mg/dL, respectively. No patients experienced IgM flare or bleeding AEs.

CONCLUSION

The therapeutic flow offers sufficient efficacy and safety in WM with HVS.

Bruton Tyrosine Kinase Inhibition: an Effective Strategy to Manage Waldenström Macroglobulinemia

PURPOSE OF REVIEW

The treatment of Waldenström macroglobulinemia (WM) has evolved over the past decade. With the seminal discoveries of MYD88 and CXCR warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) mutations in WM cells, our understanding of the disease biology and treatment has improved. The development of a new class of agents, Bruton tyrosine kinase inhibitors (BTKi), has substantially impacted the treatment paradigm of WM. Herein, we review the current and emerging BTKi and the evidence for their use in WM.

RECENT FINDINGS

Clinical trials have established the role of covalent BTKi in the treatment of WM. Their efficacy is compromised among patients who harbor CXCR4WHIM mutation or MYD88WT genotype. The development of BTKC481 mutation-mediated resistance to covalent BTKi may lead to disease refractoriness. Novel, non-covalent, next-generation BTKi are emerging, and preliminary results of the early phase clinical trials show promising activity in WM, even among patients refractory to a covalent BTKi. Covalent BTK inhibitors have demonstrated meaningful outcomes in treatment-naïve (TN) and relapsed refractory (R/R) WM, particularly among those harboring the MYD88L265P mutation. The next-generation BTKi demonstrate improved selectivity, resulting in a more favorable toxicity profile. In WM, BTKi are administered until progression or the development of intolerable toxicity. Consequently, the potential for acquired resistance, the emergence of cumulative toxicities, and treatment-related financial burden are critical challenges associated with the continuous therapy approach. By circumventing BTK C481 mutations that alter the binding site to covalent BTKi, the non-covalent BTKi serve as alternative agents in the event of acquired resistance. Head-to-head comparative trials with the conventional chemoimmunotherapies are lacking. The findings of the RAINBOW trial (NCT046152), comparing the dexamethasone, rituximab, and cyclophosphamide (DRC) regimen to the first-generation, ibrutinib are awaited, but more studies are needed to draw definitive conclusions on the comparative efficacy of chemoimmunotherapy and BTKi. Complete response is elusive with BTKi, and combination regimens to improve upon the efficacy and limit the treatment duration are also under evaluation in WM.

Waldenström macroglobulinemia: a review of pathogenesis, current treatment, and future prospects

Waldenström macroglobulinemia (WM) is a chronic B-cell lymphoproliferative disorder characterized by lymphoplasmacytic cell overgrowth in the bone marrow and increased secretion of IgM immunoglobulins into the serum. Patients with WM have a variety of clinical outcomes, including long-term survival but inevitable recurrence. Recent advances in disease knowledge, including molecular and genetic principles with the discovery of MYD88 and CXCR4 mutations, have rapidly increased patient-tolerable treatment options. WM patients may benefit from chemotherapy regimens that include rituximab-based regimens, alkylating drugs, proteasome inhibitors, monoclonal antibodies, and drugs targeting Bruton tyrosine kinase inhibitors. In light of these advancements, patients can now receive treatment customized to their specific clinical characteristics, focusing on enhancing the depth and durability of their response while limiting the adverse effects. Despite the rapidly developing therapeutic armament against WM, a lack of high-quality evidence from extensive phase 3 trials remains a significant challenge in the research. We believe clinical outcomes will keep improving when new medicines are introduced while preserving efficacy and minimizing toxicity.

How to manage waldenström's macroglobulinemia in 2024

Clinical management of Waldenström's Macroglobulinemia has seen major progress in the recent years, triggered by our improved understanding of the biology of the disease and the development of new therapies. Based on this there are multiple treatment options available for patients with WM ranging from classical immunochemotherapy to targeted approaches blocking key enzymes involved in lymphoma growth. This review summarizes our current knowledge about diagnostics and treatment of this rare but recurrent lymphoma subtype, which often presents a major clinical challenge in daily clinical life.

Long-term outcomes by bone marrow B-cell depletion from the R2W trial of bortezomib with cyclophosphamide and rituximab in Waldenstrőm macroglobulinaemia

There remains a lack of consensus as to the most appropriate primary therapy in Waldenstrőm macroglobulinemia (WM). We evaluated a novel bortezomib-based combination and developed a sensitive WM-specific flow cytometry assay (limit of detection 0.004% of leucocytes) to assess bone marrow (BM) response. Sixty treatment-naïve WM patients were enroled into this phase II trial and randomised (2:1) to receive cyclophosphamide and rituximab with either bortezomib (BRC) or fludarabine (FCR). The primary objective was to assess the overall response rate (ORR) in eligible patients receiving BRC (N = 41). An ORR of 97.6% (95%CI:87.1-99.9) was observed; 27 (65.9%) patients remain alive without progression after 62.6 months median follow-up, with 2-, 3- and 5-year progression-free survival (PFS) rates of 92.7% (95%CI:79.0-97.6), 80.5% (95%CI:64.8-89.7) and 65.5% (95%CI:48.8-77.9). Persistent WM B-cells were demonstrable in 19/38 patients at the end of treatment (median 0.24%, range 0.02-11.2%). PFS was markedly longer in patients with BM B-cell depletion (<0.004%) compared to those who had persistent BM B-cells detectable at end of treatment (HR = 0.06, 95%CI:0.01-0.47, p < 0.001), and remained independently associated after adjusting for baseline risk stratification or investigator-assessed response. BRC is a tolerable, highly efficacious regimen for treatment-naïve WM patients. BM B-cell depletion is independently associated with patient outcomes.

Ibrutinib and venetoclax as primary therapy in symptomatic, treatment-naïve Waldenström macroglobulinemia

ABSTRACT

Concurrent Bruton tyrosine kinase and BCL2 inhibition has not yet been investigated in Waldenström macroglobulinemia (WM). We performed an investigator-initiated trial of ibrutinib and venetoclax in symptomatic treatment-naïve patients with MYD88-mutated WM. Patients received ibrutinib 420 mg once daily (cycle 1), followed by a ramp-up of venetoclax to 400 mg daily (cycle 2). The combination was then administered for 22 additional 4-week cycles. The attainment of very good partial response (VGPR) was the primary end point. Forty-five patients were enrolled in this study. The median baseline characteristics were as follows: age 67 years, serum IgM 43 g/L, and hemoglobin 102 g/L. Seventeen patients (38%) carried CXCR4 mutations. Nineteen patients (42%) achieved VGPR. Grade 3 or higher adverse events included neutropenia (38%), mucositis (9%), and tumor lysis syndrome (7%). Atrial fibrillation occurred in 3 (9%), and ventricular arrhythmia in 4 (9%) patients that included 2 grade 5 events. With a median follow-up of 24.4 months, the 24-month progression-free survival (PFS) and overall survival (OS) rates were 76% and 96%, respectively, and were not impacted by CXCR4 mutations. The median time on therapy was 10.2 months, and the median time after the end of therapy (EOT) was 13.3 months. Eleven of the 12 progression events occurred after EOT, and the 12-month PFS rates after EOT were 79%; 93% if VGPR was attained, and 69% for other patients (P = .12). Ibrutinib and venetoclax induced high VGPR rates and durable responses after EOT, although they were associated with a higher-than-expected rate of ventricular arrhythmia in patients with WM, leading to early study treatment termination. This trial was registered at www.clinicaltrials.gov as #NCT04273139.

Waldenström Macroglobulinemia: Targeted Agents Taking Center Stage

With the worldwide approval of the oral covalent Bruton tyrosine kinase (BTK) inhibitors ibrutinib and zanubrutinib for treating patients with Waldenström macroglobulinemia (WM), targeted agents have certainly taken center stage in the therapeutic landscape of WM. This review discusses the biological and clinical data supporting current and up-and-coming targeted agents in WM. Bruton tyrosine kinase inhibitors induce fast, deep, and durable responses in patients with WM, comparable to chemoimmunotherapy; however, there is a glaring absence of comparative studies between these regimens. The high response and progression-free survival rate and the ease of administration of BTK inhibitors must be balanced against their specific adverse-event profile with unique toxicity (e.g., bleeding and cardiac arrhythmia) and the indefinite duration of the therapy. Novel targeted agents of interest include BCL2 antagonists (e.g., venetoclax and sonrotoclax) and non-covalent BTK inhibitors (e.g., pirtobrutinib and nemtabrutinib), among others. The therapeutic landscape of patients with WM will benefit from the robust participation of patients in clinical trials.

Current approach to Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a unique CD20+, B-cell non-Hodgkin lymphoma, characterized by lymphoplasmacytic infiltration of the bone marrow and circulating monoclonal immunoglobulin M. The clinical manifestations and outcomes of patients are highly variable. High-level evidence supports integration of monoclonal anti-CD20 antibody, rituximab, to the chemotherapy backbone to treat WM. However, its contemporary management has become more nuanced, with deeper understanding of the pathophysiology and incorporation of Bruton's tyrosine kinase (BTK) inhibitors to the treatment paradigm. Prior knowledge of the patients' MYD88L265P and CXCR4 mutation status may aid in the treatment decision-making. Currently, the two frequently utilized approaches include fixed-duration chemoimmunotherapy and BTK inhibitor-based continuous treatment until progression. Randomized trials comparing these two vastly divergent approaches are lacking. Recent studies demonstrating efficacy of B cell lymphoma-2 (BCL2) inhibitors and non-covalent BTK inhibitors in patients, previously exposed to a covalent BTK inhibitor, are a testament to the rapidly expanding options against WM.

Efficacy and safety of front-line treatment regimens for Waldenstrom macroglobulinaemia: a systematic review and meta-analysis

Rituximab-based chemo-immunotherapy is currently the standard first-line treatment for Waldenstrom macroglobulinaemia (WM), while ibrutinib has emerged as an alternative. In the absence of randomised trials (RCTs) comparing these regimens, the optimal first-line treatment for WM remains uncertain. In this systematic review and meta-analysis, we sought to assess the efficacy and safety of first-line treatment regimens for WM. We searched key databases from January 2007 to March 2023, including phase II and III trials, including treatment-naïve WM patients treated with rituximab-based regimens or ibrutinib. Response rates, progression-free survival (PFS), overall survival (OS), and toxicities were evaluated. Four phase III and seven phase II trials were included among 736 unique records. Pooled response rates from all comparative and non-comparative trials were 46%, 33% and 26% for bendamustine rituximab (BR), bortezomib-dexamethasone, cyclophosphamide, rituximab (BDRC) and ibrutinib rituximab (IR), respectively. Two-year pooled PFS was 89%, 81% and 82% with BR, BDRC and IR, respectively. Neuropathy was more frequent with bortezomib, while haematologic and cardiac toxicities were more common with chemo-immunotherapy and ibrutinib-based regimens respectively. Our findings suggest that BR yields higher response rates than bortezomib or ibrutinib-based combinations. RCTs comparing BR against emerging therapies, including novel Bruton Tyrosine Kinase Inhibitors, are warranted.

The Management of Relapsed or Refractory Waldenström's Macroglobulinemia

Waldenström's macroglobulinemia (WM) is an immunoglobulin M monoclonal gammopathy produced by a bone marrow lymphoplasmacytic lymphoma, an indolent non-Hodgkin lymphoma in which the cure is still an unmet challenge. Combinations with alkylating agents, purine analogs, and monoclonal antibodies, Bruton tyrosine kinase, and proteasome inhibitors are used for the treatment of relapsed and refractory patients. Moreover, new additional agents can be seen on the horizon as potential effective therapies. No consensus on a preferred treatment in the relapsed setting is available yet.

Future Directions in the Frontline Management of Waldenström Macroglobulinemia

Despite substantial progress in the clinical management of Waldenström's Macroglobulinemia (WM) and the emergence of chemotherapy-free approaches such as BTK inhibitors, WM is still a disease in which current treatments fail to cure and are in part associated with significant toxicities, compromising treatment outcome and quality of life. Thus, the vision for future front-line therapy should be to develop regimens which combine improved efficacy and excellent applicability with a low toxicity profile. Conventional immunochemotherapy such as bendamustine-rituximab is highly active but limited by hematotoxicity and long-lasting immunosuppression. Thus, further intensification of this treatment concept will most likely not be successful. Chemotherapy-free approaches such as BTK inhibitors have already changed the treatment landscape in WM, but still have major limitations such as the need for non-fixed duration treatment. Most probably, the combination of non-chemotherapy based, targeted approaches with different modes of action will ensure that we at least come closer to our vision of achieving functional cure in WM in the near future.

Proteasome Inhibitor-Based Regimens in the Frontline Management of Waldenström Macroglobulinemia

Proteasome inhibitors (PIs) have long been used in myeloma therapy but also for Waldenström macroglobulinemia. Their use has been successful and has also been investigated for the frontline management of the disease. Bortezomib was effective either as a single agent or in combination with other regimens with high response rates observed in most studies, despite its adverse effects, especially neurotoxicity, which remains a major concern. Clinical trials with second-generation PIs such as carfilzomib and ixazomib have also been conducted, always in combination with immunotherapy in previously untreated patients. They have been shown to be active and neuropathy-sparing treatment options.

Report of consensus panel 1 from the 11th International Workshop on Waldenstrom's Macroglobulinemia on management of symptomatic, treatment-naïve patients

Consensus Panel 1 (CP1) of the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11) was tasked with updating guidelines for the management of symptomatic, treatment-naïve patients with WM. The panel reiterated that watchful waiting remains the gold standard for asymptomatic patients without critically elevated IgM or compromised hematopoietic function. For first-line treatment, chemoimmunotherapy (CIT) regimens such as dexamethasone, cyclophosphamide, rituximab (DRC), or bendamustine, rituximab (Benda-R) continue to play a central role in managing WM, as they are effective, of fixed duration, generally well-tolerated, and affordable. Covalent BTK inhibitors (cBTKi) offer a continuous, generally well-tolerated alternative for the primary treatment of WM patients, particularly those unsuitable for CIT. In a Phase III randomized trial updated at IWWM-11, the second-generation cBTKi, zanubrutinib, was less toxic than ibrutinib and induced deeper remissions, thus categorizing zanubrutinib as a suitable treatment option in WM. While the overall findings of a prospective, randomized trial updated at IWWM-11 did not show superiority of fixed duration rituximab maintenance over observation following attainment of a major response to Benda-R induction, a subset analysis showed benefit in patients >65 years and those with a high IPPSWM score. Whenever possible, the mutational status of MYD88 and CXCR4 should be determined before treatment initiation, as alterations in these 2 genes predict sensitivity towards cBTKi activity. Treatment approaches for WM-associated cryoglobulins, cold agglutinins, AL amyloidosis, Bing-Neel syndrome (BNS), peripheral neuropathy, and hyperviscosity syndrome follow the common principle of reducing tumor and abnormal protein burden rapidly and deeply to improve symptoms. In BNS, ibrutinib can be highly active and produce durable responses. In contrast, cBTKi are not recommended for treating AL amyloidosis. The panel emphasized that continuous improvement of treatment options for symptomatic, treatment-naïve WM patients critically depends on the participation of patients in clinical trials, whenever possible.

Report of consensus Panel 4 from the 11th International Workshop on Waldenstrom's macroglobulinemia on diagnostic and response criteria

Consensus Panel 4 (CP4) of the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11) was tasked with reviewing the current criteria for diagnosis and response assessment. Since the initial consensus reports of the 2nd International Workshop, there have been updates in the understanding of the mutational landscape of IgM related diseases, including the discovery and prevalence of MYD88 and CXCR4 mutations; an improved recognition of disease related morbidities attributed to monoclonal IgM and tumor infiltration; and a better understanding of response assessment based on multiple, prospective trials that have evaluated diverse agents in Waldenstrom's macroglobulinemia. The key recommendations from IWWM-11 CP4 included: (1) reaffirmation of IWWM-2 consensus panel recommendations that arbitrary values for laboratory parameters such as minimal IgM level or bone marrow infiltration should not be used to distinguish Waldenstrom's macroglobulinemia from IgM MGUS; (2) delineation of IgM MGUS into 2 subclasses including a subtype characterized by clonal plasma cells and MYD88 wild-type, and the other by presence of monotypic or monoclonal B cells which may carry the MYD88 mutation; and (3) recognition of "simplified" response assessments that use serum IgM only for determining partial and very good partial responses (simplified IWWM-6/new IWWM-11 response criteria). Guidance on response determination for suspected IgM flare and IgM rebound related to treatment, as well as extramedullary disease assessment was also updated and included in this report.

Bortezomib-based chemotherapy for patients with Waldenström macroglobulinemia: a single-center experience

Waldenström Macroglobulinemia (WM) is a rare type of non-Hodgkin lymphoma with no standard first-line treatment, and the disease is still incurable. This study evaluated the clinical efficacy, safety, and prognostic factors of bortezomib-based chemotherapy as initial treatment in WM patients. We retrospectively analyzed the clinical data collected from 44 newly diagnosed WM patients treated with bortezomib-based regimens at the Affiliated Hospital of Nantong University from December 2011 to June 2021. Univariate and multivariate analyses were used to assess prognostic factors for overall survival (OS) and progression-free survival (PFS). The median age was 67 years old, with an overall response rate (ORR) of 93.2%, complete response (CR) rate of 6.8%, and very good partial response (VGPR) rate of 29.5%. With a median follow-up of 39 months, the 2-year overall survival (OS) and 2-year PFS rates were 88.0% and 59.0%, respectively. By the last follow-up, eight patients (18.2%) had died. Univariate analysis showed patients with B symptoms, elevated LDH, international prognostic stage system of WM (IPSSWM) stage III, high Revised IPSSWM (R-IPSSWM) score, and those who did not achieve VGPR were associated with shorter PFS. And patients with B symptoms, with high R-IPSSWM score, and who do not achieve VGPR also had shorter OS than their counterparts. Multivariate analysis confirmed that failure to achieve VGPR was an independent adverse prognostic factor for OS and PFS. In conclusion, we showed that bortezomib-based chemotherapy effectively treated newly diagnosed patients with WM. However, combinations of drugs with different mechanisms are recommended for patients with a high tumor burden. In addition, deep remission can improve patients' survival.

IgM-Related Immunoglobulin Light Chain (AL) Amyloidosis

Waldenström macroglobulinemia (WM) is a rare lymphoplasmacytic disorder characterized by an IgM paraprotein. The clinical presentation of WM varies and can include common manifestations such as anemia and hyperviscosity, in addition to less common features such as cryoglobulinemia, IgM-related neuropathy, and immunoglobulin light chain (AL) amyloidosis. Amyloidosis is a protein-folding disorder in which vital organ damage occurs due to the accumulation of misfolded protein aggregates. The most common type of amyloidosis in patients with an IgM paraprotein is AL amyloidosis, although other types of amyloidosis may occur. IgM-related amyloidosis has distinct clinical features when compared with other subtypes of AL amyloidosis. This review highlights the diagnostic criteria of IgM-related AL amyloidosis, as well as the clinical characteristics and treatment options for this disorder.

Bortezomib-based therapy is effective and well tolerated in frontline and multiply pre-treated Waldenström macroglobulinaemia including BTKi failures: A real-world analysis

Waldenström macroglobulinemia (WM) is a rare, incurable low grade lymphoma following a relapsing trajectory. Management strategies have evolved with the introduction of targeted therapy including new classes of Bruton tyrosine kinase inhibitor (BTKi). Treatment may however be limited particularly at relapse by a lack of drug availability and tolerability. We assessed the real-world efficacy and tolerability of bortezomib-containing regimens in patients with WM at frontline and relapse including those with prior BTKi resistance. Forty-one patients were identified with 44 bortezomib-containing regimens administered (n = 12 frontline, n = 32 relapse). Of patients treated at relapse, the median prior lines of therapy was 3 (range 1-7). 24% (10/41) of the cohort were refractory or intolerant to BTKi prior to bortezomib delivery. The median follow-up after bortezomib administration was 34 months (range 0-131). Overall response rate was 88%; 2-year overall survival and progression-free survival were 90% (95% confidence interval [CI] 73-96) and 76% (95% CI 55-87), respectively. Median time-to-next-treatment was 66 months. Neuropathy (grade 1-2) occurred in 24% (8/34) and did not result in treatment cessation in any case. Gastrointestinal disturbance occurred in 7% (3/41). Treatment discontinuations were rare (1/44; 2%), suggesting a manageable safety profile. Major response rate was comparable in those with prior BTKi compared with those without (75% [6/8] vs 84% [27/32], p = 0.61). Bortezomib should be considered as a treatment modality particularly in those who are refractory to BTKi.

First-Line Treatment of Waldenström’s Macroglobulinaemia: Considerations Based on the Dutch National Guideline

Waldenström macroglobulinemia (WM) is a rare B-cell Non-Hodgkin Lymphoma. There are only few prospective randomized clinical trials to guide treatment recommendations and there is no international consensus on a preferred first line treatment approach. In the recently revised Dutch guideline for WM, we describe recommendations for practice based as much as possible on the known data. Here, we summarize the considerations for first-line treatment based on these Dutch guidelines. Available evidence is summarized, including efficacy and toxicity data. Combinations of Rituximab with chemotherapy, proteasome inhibition or BTK-inhibition are all valid first line treatment options. The Dutch WM working group considers Dexamethasone/Rituximab/Cylofosfamide (DRC) a suitable first-line treatment for many WM patients, given the efficacy, the relatively mild toxicity profile and the extensive experience with this regimen. However, the long-term toxicities of DRC are unclear and need further clarification. Other regimens such as R-bendamustine, R-Bortezomib-dexamethason are also effective options, however with specific toxicities. BTK-inhibitors are not a preferred option in first line for most patients in the Dutch WM guidelines because of the need for longterm treatment and toxicities. Based on patient preferences research, future clinical trials should focus on effective fixed-duration regimens with non-cytotoxic therapies that have a favorable toxicity profile. Further development of (combinations with) BCL-2 inhibititors, novel proteasome inhibitors and BTK-inhibition could be interesting. In addition T-cell-directed treatments including bispecific antibodies as a monotherapy or combined with other novel agents deserve further study in WM.

Should Patients with Waldenström Macroglobulinemia Receive a BTK Inhibitor as Frontline Therapy?

Waldenström Macroglobulinemia (WM) is a rare indolent lymphoma with heterogeneous clinical presentation. As there are no randomised trials suggesting the best treatment option in treatment-naive patients, guidelines suggest either rituximab-combining regimens or BTK-inhibitors (BTKi) as feasible alternatives. Several factors play in the decision-making process: patients’ age and fitness, disease characteristics and genotype. Chemoimmunotherapy (CIT) represents a fixed-duration, less expensive and effective option, able to achieve prolonged time-to-next treatment even in patients with unfavourable genotypes. Immunosuppression and treatment-related second cancers may represent serious concerns. Proteasome-inhibitor-based regimens are effective with rapid disease control, although bortezomib-related neuropathy discourages the choice of these agents and treatment schedules may not be easily manageable in the elderly. BTKi have demonstrated high rates of response and prolonged survival together with the convenience of an oral administration and limited cytopenias. However, outcomes are impacted by genotype and some concerns remain, in particular the continuous drug exposure that may result in extra-haematological complications and drug resistance. Although next-generation BTKi have improved treatment tolerance, the question whether BTKi should be offered as frontline therapy to every patient is still debated. Giving fixed-duration schedule, prolonged time-to-next treatment and outcomes independent of genotype, CIT is still our preferred choice in WM. However, BTKi remain a valuable option in frail patients unsuitable for CIT.

A Canadian Perspective on the Treatment of Waldenström Macroglobulinemia

Waldenström macroglobulinemia (WM) is a slowly progressing B-cell non-Hodgkin lymphoma characterized by monoclonal IgM gammopathy in the blood and infiltration of the bone marrow by clonal lymphoplasmacytic cells. As an incurable disease, the goals for therapy for WM are to relieve symptoms, slow disease progression, prevent organ damage, and maintain quality of life. However, given the rarity of WM, clinical trials comparing treatments for WM are limited and there is no definitive standard of care. The selection of first-line WM therapy is thus based on patient factors, disease characteristics, and drug access, with bendamustine-rituximab and Bruton's tyrosine kinase (BTK) inhibitor therapy considered preferred treatments. Other treatments such as proteasome inhibitor- or purine analogue-based therapy, alternative chemoimmunotherapy, and autologous stem cell transplantation are generally reserved for the relapsed setting but may be used in rare circumstances in earlier lines of therapy. This paper summarizes the efficacy and safety of these WM therapies and discusses considerations for treatment from a Canadian perspective.

Waldenstrom Macroglobulinemia: Tailoring Therapy for the Individual

With the introduction of multiple new effective therapeutic options for the treatment of macroglobulinemia, a structured approach to management of this rare lymphoma is currently needed. A review of phase II and III treatment trials over the past 20 years was performed, and high-quality trials are summarized in this manuscript. Because of the lack of large prospective trials comparing different classes of therapy, a uniform recommendation applicable to all patients cannot be made, and the approach must be individualized incorporating patient preferences, comorbidities, and the range of therapeutic toxicities. Therapeutic options for patients with newly diagnosed and previously treated macroglobulinemia are presented on the basis of the best available evidence in the literature.

Treatment and Survival Outcomes of Waldenstrom Macroglobulinemia in Latin American Patients: A Multinational Retrospective Cohort Study

Waldenstrom Macroglobulinemia (WM) is a rare lymphoma with distinct clinical features, and data from Latin American patients are lacking. Therefore, we aim to investigate the clinical, therapy, and outcome patterns of WM in Latin America.

Waldenstrom Macroglobulinemia (WM) is a rare lymphoma with distinct clinical features. Data from Latin American WM patients are lacking. In this article, we report, for the first time, the results of a retrospective analysis focused on the clinical, therapy, and outcome patterns of WM in Latin America. Moreover, we have validated the IPSSWM score as a prognostic factor for mortality and disease progression. Despite the limitations we acknowledge, this is the first study to provide novel real-world data on WM in Latin America.

Dutch Physician's Perspectives on Diagnosis and Treatment of Waldenström's Macroglobulinemia Before and After the Implementation of a National Guideline

Waldenström's macroglobulinemia (WM), a rare low-grade B-cell non-Hodgkin lymphoma (NHL), has a distinct clinical presentation and different treatment-related side effects compared with other NHL. Currently, a wide variety of therapeutic agents are available for the treatment of WM but there is no consensus on optimal treatment in first line and/or at relapse. The aim of this survey was to evaluate the current knowledge and perspectives of hematologists on diagnosis and treatment of WM. Also, we compare these results to a similar survey done before the publication of the first Dutch national guideline, in order to evaluate the impact of the implementation of a national guideline. A link to an online survey was sent out to all registered hematologists and hemato-oncologists in the Netherlands with the request to participate. The survey contained questions regarding the preferred diagnostic and treatment methods in patients with WM as well as treatment goals. We also compared physicians preferred treatment goals to those of patients (as studied in a recent nationwide patient questionnaire). Ninety-five responses (30% response rate) were obtained, out of which 82 (86%) surveys were complete. The respondents most commonly used dexamethasone-rituximab-cyclophosphamide as first-line treatment. For second-line treatment, bendamustine with rituximab and ibrutinib monotherapy were the most frequently applied. Compared with the initial survey, serum IgM M-protein was determined in all cases, MYD88 mutation analysis was currently widely implemented, prevention of an IgM "flare" was uniformly managed by the respondents and use of rituximab-cyclophosphamide-vincristine-prednisone was entirely abandoned. Physicians differed somewhat from patients with regard to most important treatment goals. The approach to diagnostic methods and treatment options in WM was more consistent with international guidelines and was more homogeneous after implementation of the national guideline. These data indicate an increase in knowledge on WM diagnosis and treatment. This may have resulted from implementation of a local guideline or the global rise in awareness and attention for WM.

When a Monoclonal Gammopathy Is Not Multiple Myeloma

Our knowledge of monoclonal gammopathies is continuously evolving. Once accepted as a possible precursor condition to multiple myeloma, monoclonal gammopathies as an entity are now associated with many renal, neurologic, and dermatologic disorders of clinical significance. This change has created a challenge for patients and clinicians, as a monoclonal gammopathy may be a harbinger not of multiple myeloma but of other lymphoproliferative disorders such as light-chain amyloidosis and Waldenström macroglobulinemia. Early recognition of monoclonal gammopathies along with a careful workup are essential in determining the next steps in the care of a given patient. Recognition has become all the more important as we understand how to triage the 4% to 9% of patients with monoclonal gammopathies depending on age, with the goal of limiting overdiagnosis and misdiagnosis. In this review, we focus on treatment strategies for patients with monoclonal gammopathies that are not multiple myeloma, including smoldering multiple myeloma, light-chain amyloidosis, and Waldenström macroglobulinemia.

Diagnosis and management of Waldenström macroglobulinaemia-A British Society for Haematology guideline

SCOPE

The objective of this guideline is to provide healthcare professionals with clear guidance on the management of patients with Waldenström macroglobulinaemia. In individual patients, circumstances may dictate an alternative approach.

METHODOLOGY

This guideline was compiled according to the British Society for Haematology (BSH) process at http://www.b-s-h.org.uk/guidelines/proposing-and-writing-a-new-bsh-guideline/. Recommendations are based on a review of the literature using Medline, Pubmed, Embase, Central, Web of Science searches from beginning of 2013 (since the publication of the previous guidelines) up to November 2021. The following search terms were used: Waldenström('s) macroglobulin(a)emia OR lymphoplasmacytic lymphoma, IgM(-related) neuropathy OR cold h(a)emagglutinin disease OR cold agglutinin disease OR cryoglobulin(a)emia AND (for group a only) cytogenetic OR molecular OR mutation OR MYD88 OR CXCR4, management OR treatment OR transfusion OR supportive care OR plasma exchange OR plasmapheresis OR chemotherapy OR bendamustine OR bortezomib OR ibrutinib OR fludarabine OR dexamethasone OR cyclophosphamide OR rituximab OR everolimus, bone marrow transplantation OR stem cell transplantation. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) nomenclature was used to evaluate levels of evidence and to assess the strength of recommendations. The GRADE criteria can be found at http://www.gradeworkinggroup.org. Review of the manuscript was performed by the British Society for Haematology (BSH) Guidelines Committee Haemato-Oncology Task Force, the BSH Guidelines Committee and the Haemato-Oncology sounding board of BSH. It was also on the members section of the BSH website for comment. It has also been reviewed by UK Charity WMUK; these organisations do not necessarily approve or endorse the contents.

Multi-catalytic Sites Inhibition of Bcl2 Induces Expanding of Hydrophobic Groove: A New Avenue Towards Waldenström Macroglobulinemia Therapy

B-cell lymphoma 2 (Bcl2) is a key protein regulator of apoptosis. The hydrophobic groove in Bcl2 is a unique structural feature to this class of enzymes and found to have a profound impact on protein overall structure, function, and dynamics. Dynamics of the hydrophobic groove is an essential determinant of the catalytic activity of Bcl2, an implicated protein in Waldenström macroglobulinemia (WM). The mobility of α3-α4 helices around the catalytic site of the protein remains crucial to its activity. The preferential binding mechanisms of the multi-catalytic sites of the Bcl2 enzyme have been a subject of debate in the literature. In addition to our previous report on the same protein, herein, we further investigate the preferential binding modes and the conformational implications of Venetoclax-JQ1 dual drug binding at both catalytic active sites of Bcl2. Structural analysis revealed asymmetric α3-α4 helices movement with the expansion of the distance between the α3 and α4 helix in Venetoclax-JQ1 dual inhibition by 15.2% and 26.3%, respectively when compared to JQ1 and Venetoclax individual drug inhibition-resulting in remarkable widening of hydrophobic groove. Moreso, a reciprocal enhanced binding effect was observed: Venetoclax increased the binding affinity of JQ1 by 11.5%, while the JQ1 fostered the binding affinity of Venetoclax by 16.3% compared with individual inhibition of each drug. This divergence has also resulted in higher protein stability, and prominent correlated motions were observed with the least fluctuations and multiple van der Waals interactions. Findings offer vital conformational dynamics and structural mechanisms of enzyme-single ligand and enzyme-dual ligand interactions, which could potentially shift the current therapeutic protocol of Waldenström macroglobulinemia.

Current approach to Waldenström Macroglobulinemia

Waldenström Macroglobulinemia (WM) is a unique, low grade, IgM lymphoplasmacytic lymphoma with a heterogeneous clinical course. A paucity of high-grade evidence from large phase 3 trials remains a major issue in the field despite a rapidly expanding therapeutic armamentarium against WM. Prior knowledge of the patients' MYD88^L265P and CXCR4 mutation status aids in treatment decision making if Bruton's tyrosine kinase (BTK) inhibitor therapy is being considered. Head-to head comparative data to inform optimal approach are lacking, and a particularly vexing issue for the clinicians is choosing between fixed-duration bendamustine-rituximab (BR) therapy and an indefinite BTK inhibitor-based regimen, given that both approaches are well tolerated and effective, particularly for the patient population harboring MYD88^L265P mutation. For the patients with MYD88^WT genotype, chemo-immunotherapy such as BR is preferred, although zanubrutinib, a potent second generation BTK inhibitor, with its reduced off target effects and greater BTK occupancy compared to its predecessor, ibrutinib, has also recently shown activity in MYD88^WT WM. This review summarizes the current literature pertaining to the diagnosis, prognosis, and the treatment of WM.

Successful treatment with bortezomib for refractory fever associated with myelodysplastic syndrome with underlying lymphoplasmacytic lymphoma

We report a case of fever of unknown origin in a patient with MDS associated with IgM-MGUS. The patient was positive for MYD88 mutation, and chemotherapy for LPL/WM improved the fever. Analysis of MYD88 and the effect of chemotherapy on LPL/WM finally revealed the latent LPL/WM in this case.

Combining Ixazomib With Subcutaneous Rituximab and Dexamethasone in Relapsed or Refractory Waldenström's Macroglobulinemia: Final Analysis of the Phase I/II HOVON124/ECWM-R2 Study

PURPOSE

Proteasome inhibitors are effective in Waldenström's macroglobulinemia (WM) but require parenteral administration and are associated with polyneuropathy. We investigated efficacy and toxicity of the less neurotoxic oral proteasome inhibitor ixazomib combined with rituximab, in patients with relapsed WM.

METHODS

We conducted a multicenter phase I/II trial with ixazomib, rituximab, and dexamethasone (IRD). Induction consisted of eight cycles IRD wherein rituximab was started in cycle 3, followed by rituximab maintenance. Phase I showed feasibility of 4 mg ixazomib. Primary end point for phase II was overall response rate (ORR [≥ minimal response]) after induction.

RESULTS

A total of 59 patients were enrolled (median age, 69 years; range, 46-91 years). Median number of prior treatments was 2 (range, 1-7); 70% had an intermediate or high WM-IPSS (International Prognostic Scoring System for WM) score. After eight cycles, ORR was 71% (42 out of 59) (14% very good partial response [PR], 37% PR, and 20% minor response). Depth of response improved until month 12 (best ORR 85% [50 out of 59]: 15% very good PR, 46% PR, and 24% minor response). Median duration of response was 36 months. The average hematocrit level increased significantly (0.33-0.38 L/L) after induction (P < .001). After two cycles of ixazomib and dexamethasone, immunoglobulin M levels decreased significantly (median 3,700-2,700 mg/dL, P < .0001). Median time to first response was 4 months. Median progression-free survival and overall survival were not reached. After median follow-up of 24 months (range, 7.4-54.3 months), progression-free survival and overall survival were 56% and 88%, respectively. Toxicity included mostly grade 2 or 3 cytopenias, grade 1 or 2 neurotoxicity, and grade 2 or 3 infections. No infusion-related reactions or immunoglobulin M flare occurred with use of subcutaneous rituximab. Quality of life improved significantly after induction. In total, 48 patients (81%) completed at least six cycles of IRD.

CONCLUSION

Combination of IRD shows promising efficacy with manageable toxicity in patients with relapsed or refractory WM.

Semi-quantitative measurements of chemokine receptor 4-targeted 68Ga-pentixafor PET/CT in response assessment of Waldenström macroglobulinemia/lymphoplasmacytic lymphoma

Purpose

⁶⁸Ga-pentixafor PET/CT was reported to have a high sensitivity in detecting tumor involvement of Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL) in our previous study. We aimed to further investigate the semi-quantitative measurements of ⁶⁸Ga-pentixafor PET/CT in response assessment in WM/LPL.

Methods

Fifteen patients with WM/LPL were recruited in a prospective cohort study and underwent both ⁶⁸Ga-pentixafor and ¹⁸F-FDG PET/CT at baseline and post-treatment. PET/CT-based responses were analyzed with semi-quantitative assessments of metabolic tumor volume (MTV) and total lesions glycolysis/uptake (TLG_FDG and TLU_CXCR4), and the correlation between PET/CT-based response and clinical response, monoclonal protein and IgM response was analyzed.

Results

After chemotherapy, 5 patients had complete response or very good partial response, 8 had partial response or minimal response and 2 had progressive disease. In quantitative analysis, ⁶⁸Ga-pentixafor PET/CT-based response (measured in ∆TLU_CXCR4%, ∆MTV_CXCR4%, ∆SUVpeak%) showed a significant direct correlation with clinical response, monoclonal protein and IgM response (p < 0.01). However, ¹⁸F-FDG PET/CT-based response was independent from clinical response (p > 0.05).

Conclusions

The semi-quantitative measurements of ⁶⁸Ga-pentixafor PET/CT outperformed ¹⁸F-FDG PET/CT in response assessment of WM/LPL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00852-0.

Long-term follow-up of ibrutinib monotherapy in treatment-naive patients with Waldenstrom macroglobulinemia

Herein, we present the final report of a single-center, prospective phase II study evaluating ibrutinib 420 mg once daily in 30 treatment-naive patients with Waldenstrom macroglobulinemia (WM). The present study is registered with ClinicalTrials.Gov (NCT02604511). With a median follow-up of 50 months, the overall, major, and VGPR response rates were 100%, 87%, and 30%. The VGPR rate was numerically but not significantly lower in patients with than without CXCR4 mutations (14% vs. 44%; p = 0.09). The median time to a minor response was 0.9 months, and to a major response was 1.9 months, though were longer in those with mutated CXCR4 at 1.7 months (p = 0.07) and 7.3 months (p = 0.01). Six patients had disease progression. The median progression-free survival (PFS) was not reached, and the 4-year PFS rate was 76%. There was also a non-significant lower 4-year PFS rate in patients with than without CXCR4 mutations (59% vs. 92%; p = 0.06). The most common treatment-related adverse events were fatigue, upper respiratory infection, and hematoma. Atrial fibrillation occurred in 20% of patients. Ibrutinib monotherapy induced durable responses in treatment-naive patients with WM. CXCR4 mutations impacted VGPR attainment, time to major response, and 4-year PFS rate.

Ibrutinib effect in acquired von Willebrand syndrome secondary to Waldenström macroglobulinemia

The pathological increase of clonal IgM in Waldenström macroglobulinemia can be associated with acquired von Willebrand syndrome and can be a major risk of bleeding symptoms in this subgroup of patients with Waldenström macroglobulinemia. The Bruton tyrosine kinase inhibitor ibrutinib is one of the approved treatments for symptomatic Waldenström macroglobulinemia. However, some controversy exists regarding the use of ibrutinib in these patients with high risk of bleeding because of its antiaggregant effect that could increase the risk of bleeding. Here, we present the case of a patient with Waldenström macroglobulinemia with associated acquired von Willebrand syndrome and progressively significant bleeding symptoms, who experienced a rapid increase in von Willebrand factor with ibrutinib treatment, despite only reaching a partial response in IgM levels similar to those reached with other previous treatments. We suggest that the control over the monoclonal protein is not the only mechanism that explains the good response, improvement in the bleeding symptoms and von Willebrand factor levels. This fact could be explained by the reduced glycoprotein Ib receptor expression induced by ibrutinib and the consequent von Willebrand factor increase in peripheral blood.

How to Sequence Therapies in Waldenström Macroglobulinemia

OPINION STATEMENT

There are multiple treatment options in patients with Waldenström macroglobulinemia, including chemotherapy, monoclonal antibodies, proteasome inhibitors, and covalent Bruton tyrosine kinase (BTK) inhibitors. The choice of therapy should take into account the patient's clinical presentation, comorbidities, and preferences. A thorough discussion should take place to outline the administration, safety, and efficacy of the regimens under consideration. The patient's genomic profile can provide insightful information for the treatment selection. In the frontline and relapsed settings, we favor ibrutinib monotherapy over chemoimmunotherapy or proteasome inhibitor-based regimens in patients with MYD88 and without CXCR4 mutations. For patients with MYD88 and CXCR4 mutations or without MYD88 or CXCR4 mutations, chemoimmunotherapy or proteasome inhibitor-based regimens are favored, but efficacy data with ibrutinib in combination with rituximab and with novel covalent BTK inhibitors are emerging. Autologous stem cell transplant should be considered in special cases in the relapsed setting. Participation in clinical trials is positively encouraged in WM patients in frontline and relapsed settings. Agents of interest include the BCL2 antagonist venetoclax, the CXCR4 inhibitor mavorixafor, and the non-covalent BTK inhibitors pirtobrutinib and ARQ-531.

Ibrutinib plus rituximab for the treatment of adult patients with Waldenström's macroglobulinemia: a safety evaluation

Introduction: Waldenström's macroglobulinemia (WM), an orphan disease, is a rare low-grade B-cell lymphoplasmacytic lymphoma with unique clinical features and monoclonal IgM production. Rituximab remains to this date the backbone of most commonly used treatment combinations. The FDA/EMA approval of Ibrutinib, the first-in-class BTK inhibitor, either as monotherapy or in combination with rituximab, changed the treatment landscape of the disease.Areas covered: Clinical trial data that demonstrate mode of action, efficacy, and the safety profile of each agent will be covered. A safety analysis of the combination treatment will also be performed to point out its high efficacy and overall favorable toxicity profile. The disadvantages and treatment gaps that still exist in the treatment of WM which relate to the need for long-term ibrutinib administration and the lack of deep remissions and subsequent disease relapse, will also be reviewed.Expert opinion: The ibrutinib-rituximab combination is both effective and safe, in the newly-diagnosed and relapsed-refractory disease setting. The optimal therapeutic approach for WM patients remains however to be established. The question of which combinatory (or synergistic) regimen can allow for a fixed-treatment duration, deep and durable responses with a safe toxicity profile is being addressed in ongoing clinical trials.

Assessment of fixed-duration therapies for treatment-naïve Waldenström macroglobulinemia

Comparative data guiding initial therapy for Waldenström macroglobulinemia (WM), an infrequently encountered non-Hodgkin lymphoma, are sparse. We evaluated three commonly used rituximab-based frontline regimens: rituximab-bendamustine (R-Benda); dexamethasone, rituximab, cyclophosphamide (DRC); and bortezomib, dexamethasone, rituximab (BDR) in 220 treatment-naïve patients with WM, seen at Mayo Clinic between November 1, 2000 and October 31, 2019. The median follow-up was 4.5 (95%CI: 4-5) years. The R-Benda cohort (n = 83) demonstrated superior overall response rate (ORR: 98%), in comparison to DRC (n = 92, ORR: 78%) or BDR (n = 45, ORR: 84%) cohorts, p = 0.003. Similarly, longer progression-free survival (PFS) was evident with R-Benda use [median 5.2 vs. 4.3 (DRC) and 1.8 years (BDR), p < 0.001]. The time-to-next therapy (TTNT) favored R-Benda [median, not-reached, 4.4 (DRC) and 2.6 years (BDR), p < 0.001). These endpoints were comparable between the DRC and BDR cohorts. Overall survival (OS) was similar across the three cohorts, p = 0.77. In a subset analysis of 142 patients genotyped for MYD88^L265P mutation, the ORR, PFS and TTNT were unaffected by the patients' MYD88 signature within each cohort. In conclusion, ORR, PFS and TTNT with R-Benda are superior compared to DRC or BDR in treatment-naïve patients with active WM. The patient outcomes with any one of these three regimens are unaffected by the MYD88^L265P mutation status.

Managing complications secondary to Waldenström's macroglobulinemia

Introduction: Waldenström's macroglobulinemia (WM) is a rare lymphoma characterized by the accumulation of IgM-secreting lymphoplasmacytic cells in the bone marrow and other organs. Clinical sequelae relate to direct tissue infiltration by malignant cells but also to the physicochemical and immunological properties of the monoclonal IgM, resulting in a variety of disease-related complications.Areas covered: This narrative review, following a thorough Pubmed search of pertinent published literature, discusses complications secondary to WM, related to direct tumor infiltration, monoclonal IgM circulation, and deposition, as well as other less common ones. The description and pathophysiology of these complications were described together with their specific management strategies and in the context of available treatment options for WM (anti-CD20 monoclonal antibody-based combinations, proteasome inhibitors, BTK inhibitors, and other emerging ones).Expert opinion: The availability of many novel, active and less toxic regimens for the treatment of WM allows the management of the disease with strategies that depend on clinical presentation and disease-related complications, age, toxicity considerations, and presence of comorbidities.

Ixazomib, dexamethasone, and rituximab in treatment-naive patients with Waldenström macroglobulinemia: long-term follow-up

Proteasome inhibition is a standard of care for the primary treatment of patients with Waldenström macroglobulinemia (WM). We present the long-term follow-up of a prospective, phase II clinical trial that evaluated the combination of ixazomib, dexamethasone, and rituximab (IDR) in 26 treatment-naive patients with WM. IDR was administered as 6 monthly induction cycles followed by 6 every-2-month maintenance cycles. The MYD88 L265P mutation was detected in all patients, and CXCR4 mutations were detected in 15 patients (58%). The median time to response (TTR) and time to major response (TTMR) were 2 and 6 months, respectively. Patients with and without CXCR4 mutations had median TTR of 3 months and 1 month, respectively (P = .003), and median TTMR of 10 months and 3 months, respectively (P = .31). The overall, major, and very good partial response (VGPR) rates were 96%, 77%, and 19%, respectively. The rate of VGPR in patients with and without CXCR4 mutations were 7% and 36%, respectively (P = .06). The median progression-free survival (PFS) was 40 months, the median duration of response (DOR) was 38 months, and the median time to next treatment (TTNT) was 40 months. PFS, DOR, and TTNT were not affected by CXCR4 mutational status. The safety profile was excellent with no grade 4 adverse events or deaths to date. IDR provides a safe and effective frontline treatment option for symptomatic patients with WM. This study was registered at www.clinicaltrials.gov as #NCT02400437.

Treatment Patterns and Outcomes in a Nationwide Cohort of Older and Younger Veterans with Waldenström Macroglobulinemia, 2006-2019

Simple Summary

Waldenström macroglobulinemia is a rare cancer about which little is known. Evidence from real-world settings provides invaluable information to patients and clinicians, especially for older and/or frailer patients, a demographic often excluded from clinical trials. This study provides information about treatment patterns and outcomes from real-world cohorts of older (>70 years) and younger (≤70 years) patients. We report findings across early (2006–2012) and modern (2013–2019) eras, reflecting a transition during which the number of treatments available for Waldenström macroglobulinemia rapidly increased. We found marked improvements in treatment outcomes among older patients in the modern vs early era, with little or no improvement in outcomes among younger patients. Our findings emphasize the importance of real-world evidence in guiding patient-specific treatment decisions.

Abstract

Little is known about real-world treatment patterns and outcomes in Waldenström macroglobulinemia (WM) following the recent introduction of newer treatments, especially among older adults. We describe patterns of first-line (1 L) WM treatment in early (2006–2012) and modern (2013–2019) eras and report outcomes (overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and adverse event (AE)-related discontinuation) in younger (≤70 years) and older (>70 years) populations. We followed 166 younger and 152 older WM patients who received 1 L treatment between January 2006 and April 2019 in the Veterans Health Administration. Median follow-up was 43.5 months (range: 0.6–147.2 months). Compared to the early era, older patients in the modern era achieved improved ORRs (early: 63.8%, modern: 72.3%) and 41% lower risk of death/progression (hazard ratio (HR) for PFS: 0.59, 95% CI (confidence interval): 0.36–0.95), with little change in AE-related discontinuation between eras (HR: 0.82, 95% CI: 0.4–1.7). In younger patients, the AE-related discontinuation risk increased almost fourfold (HR: 3.9, 95% CI: 1.1–14), whereas treatment effects did not change between eras (HR for OS: 1.4, 95% CI: 0.66–2.8; HR for PFS: 1.1, 95% CI: 0.67–1.7). Marked improvements in survival among older adults accompanied a profound shift in 1 L treatment patterns for WM.

Reducing treatment toxicity in Waldenström macroglobulinemia

Introduction: Waldenström macroglobulinemia (WM) is a rare subtype of non-Hodgkin lymphoma characterized by the presence of IgM-secreting clonal lymphocytes, plasma cells, and lymphoplasmacytic cells. Many well-established treatment options are available for patients with WM. However, a unique array of side effects may occur in patients during therapy related to the underlying disease, as well as the chosen treatment regimen.Areas covered: This review summarizes the most common adverse effects that occur during treatment of WM, as well as potential strategies to decrease the risk of toxicity.Expert opinion: There are multiple highly effective treatment options for patients with WM. All these treatment options, however, can be associated with a variety of adverse events. For example, chemotherapy has been associated with the development of myeloid neoplasms, anti-CD20 monoclonal antibodies with paradoxical IgM flares and infusion reactions, proteasome inhibitors with neuropathy, and BTK inhibitors with bleeding and cardiac arrhythmias. Dose reductions, lower number of cycles and changes in route of administration are some of the tools a clinician has available for managing and minimizing toxicity. Future research will focus on improving patient safety without sacrificing the efficacy of treatment.

Clinical application of genomics in Waldenström macroglobulinemia

Waldenström Macroglobulinemia (WM) is an incurable hematologic malignancy characterized by lymphoplasmacytic infiltration of the bone marrow and the presence of monoclonal immunoglobulin (IgM). Although a portion of WM patients may experience a relatively indolent course, patients may experience IgM-related morbidity and/or disease-related mortality. This underscores the need for novel approaches to improve response and survival rates. Significant progress had been made in our understanding of the genomics and biology of WM. The discovery of the highly recurrent somatic mutations in the MYD88 gene detected in 90-95% and the CXCR4 gene detected in 30-40% of WM patients has provided an opportunity to develop novel targeted approaches. Mutational status has important implications in predicting response to therapies such as BTK inhibitors. Treatment of WM should be guided by many factors including performance status, comorbidities, goals of therapy, and toxicities. In this review, we describe how current genomics may be utilized to optimize WM treatment selection. As the therapeutic landscape of WM continues to expand with more targeted approaches, the genomics in WM will likely play a greater role in individualizing treatment.

Rapidly progressive immunoglobulin M monoclonal gammopathy presenting with nephrotic syndrome and hepatic failure

We report a 73-year-old male with no relevant past medical history who presented with nephrotic syndrome and jaundice. Subsequent studies revealed immunoglobulinM (IgM) monoclonal gammopathy. Kidney biopsy revealed monoclonal Ig deposition disease and amyloidosis. Bone marrow biopsy demonstrated <10% infiltration by lymphoplasmacytic cells. However, rapidly progressive hypergammaglobulinemia of IgM and hyperbilirubinemia were noted. Despite aggressive treatment, the patient developed acute kidney injury and complications of hepatic failure. He eventually died of pneumonia, just two months after diagnosis.

Waldenström macroglobulinemia: 2021 update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

Waldenström macroglobulinemia (WM) is a lymphoplasmacytic lymphoma with immunoglobulin M (IgM) monoclonal protein. Clinical features include anemia, thrombocytopenia, hepatosplenomegaly, lymphadenopathy, and rarely hyperviscosity.

DIAGNOSIS

Presence of IgM monoclonal protein associated with ≥10% clonal lymphoplasmacytic cells in bone marrow confirms the diagnosis. The L265P mutation in MYD88 is detectable in more than 90% of patients and is found in the majority of IgM MGUS patients.

RISK STRATIFICATION

Age, hemoglobin level, platelet count, β₂ microglobulin, LDH and monoclonal IgM concentrations are characteristics that are predictive of outcomes.

RISK-ADAPTED THERAPY

Not all patients who fulfill WM criteria require therapy; these patients can be observed until symptoms develop. Rituximab-monotherapy is inferior to regimens that combine it with bendamustine, an alkylating agent, a proteosome inhibitor, or ibrutinib. Purine nucleoside analogues are active but usage is declining in favor of less toxic alternatives. The preferred Mayo Clinic induction is rituximab and bendamustine.

MANAGEMENT OF REFRACTORY DISEASE

Bortezomib, fludarabine, thalidomide, everolimus, Bruton Tyrosine Kinase inhibitors, carfilzomib, lenalidomide, and bendamustine have all been shown to have activity in relapsed WM. Given WM's natural history, reduction of therapy toxicity is an important part of treatment selection.

Zanubrutinib for the treatment of Waldenström Macroglobulinemia

Introduction: Waldenström Macroglobulinaemia (WM) is a heterogeneous, incurable condition which often relapses after chemoimmunotherapy. Novel therapies such as Bruton tyrosine-kinase (BTK) inhibitors have shown to be efficacious in treating WM but with an established, significant toxicity profile seen in the first-generation inhibitor Ibrutinib. Zanubrutinib is a selective, potent BTK inhibitor with the potential to reduce toxicity and improve efficacy. Areas covered: This review examines the activity of Zanubrutinib in treating treatment-naïve and relapsed refractory WM and it's toxicity profile when compared to Ibrutinib. Outcomes from the AU003 and ASPEN studies will be examined in detail including a particular focus on MYD88^WT and CXCR4^WHIM disease. Strengths and weaknesses of this treatment approach will be highlighted and future directions for research will be identified. Expert opinion: Zanubrutinib induces deeper responses and have greater activity in MYD88^WT and CXCR4^WHIM WM. Zanubrutinib also has a favorable toxicity profile when compared to Ibrutinib. This may potentially translate to lower discontinuation rates, improved quality of life and ultimately longer progression-free survival in patients with WM.

Management of Waldenström macroglobulinemia in 2020

The management of Waldenström macroglobulinemia (WM) has evolved tremendously with recent genomic discoveries that correlate with clinical presentation and could help to tailor treatment approaches. The current diagnosis of WM requires clinicopathological criteria, including bone marrow involvement by lymphoplasmacytic lymphoma cells, a serum immunoglobulin M (IgM) monoclonal paraprotein, and presence of the MYD88 L265P mutation. Once the diagnosis is established, the relationship between the patient's symptoms and WM should be carefully investigated, because therapy should be reserved for symptomatic patients. Bone marrow involvement and serum levels of IgM, albumin, and β2-microglobulin can be used to estimate the time until treatment initiation. The treatment of WM patients should be highly personalized, and the patient's clinical presentation, comorbidities, genomic profile, and preferences, as well as toxicity of the treatment regimens, should be taken into account. Alkylating agents (bendamustine, cyclophosphamide), proteasome inhibitors (bortezomib, carfilzomib, ixazomib), anti-CD20 monoclonal antibodies (rituximab, ofatumumab), and Bruton tyrosine kinase (BTK) inhibitors (ibrutinib, acalabrutinib, zanubrutinib) are safe and highly effective treatment options in patients with WM. Because novel covalent and noncovalent BTK inhibitors (tirabrutinib, vecabrutinib, LOXO-305, ARQ-531), BCL2 antagonists (venetoclax), and CXCR4-targeting agents (ulocuplumab, mavorixafor) are undergoing clinical development in WM, the future of WM therapy certainly appears bright and hopeful.

Trends in Incidence and Mortality of Waldenström Macroglobulinemia: A Population-Based Study

Background: The incidence of Waldenström macroglobulinemia (WM) has increased in certain groups over several decades in the United States. It is unclear whether the increasing incidence is associated with mortality trends. Methods: The incidence and incidence-based mortality (IBM) rates were obtained from the Surveillance, Epidemiology, and End Results (SEER) database (1980-2016) with SEER^*Stat software. The secular trends stratified by demographic characteristics were analyzed by joinpoint regression. Results: The incidence of WM showed an initial rapid increase from 1980 to 1993 {annual percentage change (APC), 14.1% [95% confidence interval (CI), 10 to 18.4%]}, whereas it began to stabilize from 1993 to 2016 [APC, 0.5% (95% CI, -0.3 to 1.3%)]. The WM IBM trend followed a similar pattern, with a decrease occurring around 1994. The trends in the incidence and mortality significantly differed according to geographic location, race, age, sex, primary site of involvement and subtype, which could help in further investigations into the specific etiology. Moreover, a dramatic increase in the 5-year survival rate from the 1980s to 2010s was observed (47.84 vs. 69.41%). Conclusions: Although both the incidence and IBM of WM continued to increase during the study period, a reduction in the rate of increase occurred around 1993. We believe that further advances in healthcare delivery and research can ensure a low mortality rate. Future studies can use the findings of this paper to monitor the results of WM therapy.

Emerging drugs for the treatment of Waldenström macroglobulinemia

INTRODUCTION

Waldenström's Macroglobulinemia (WM) is an indolent lymphoma with uniquely distinct and heterogenous clinical and genomic profiles. Clonal lymphoplasmacytic cells secrete monoclonal IgM. More than 90% of patients harbor a mutation in MYD88 gene, leading to the constitutive activation of downstream pathways, involving BTK-mediated signaling. The use of BTK inhibitors has changed the treatment landscape of WM and has paved the way for new approaches to therapy.

AREAS COVERED

WM is an orphan disease and ibrutinib is the only FDA/EMA approved agent. Currently established agent combinations will be reviewed with a focus on emerging therapeutic options. These include second generation inhibitors, agents that target other molecules in the BCR signaling pathway, CXCR4 inhibitors, proteasome inhibitors and anti-CD38 antibodies. The current research goal is to establish a combination that can induce deep and durable responses with minimal associated toxicity. In addition, agents that can overcome ibrutinib resistance or act in a synergistic manner with BTKi are under investigation.

EXPERT OPINION

The optimal therapeutic approach for WM patients is not currently established. The question of whether a combinatory (or synergistic) regimen to overcome resistance and allow for fixed- duration treatment will allow for deep/durable responses is being addressed in ongoing clinical trials.