Characterization of familial Waldenström's macroglobulinemia

Incidence and Risk of Secondary Malignancy in Patients with Waldenström Macroglobulinemia: A Population-Based Analysis

Waldenström macroglobulinemia (WM) is a rare lymphoplasmacytic lymphoma which may predispose individuals to development of secondary malignancies (SMs). The Surveillance, Epidemiology, and End Results (SEER) database is a comprehensive registry of cancer patients in the United States reporting on a wide set of demographic variables. Using the SEER-18 dataset, analyzing patients from 2000 to 2018, we aimed to assess the incidence of SMs in WM patients. Patient characteristics such as gender, age, race, and latency were identified, and respective standardized incidence ratios (SIRs) and absolute excess risks (AERs) were calculated to compare to the general population. Of the 4,112 eligible WM patients identified, SMs were reported in 699 (17%) patients. The overall risk of developing SM, second primary malignancy, and secondary hematological malignancy was significantly higher in WM patients compared to the general population. Our findings show that WM patients had a 53% higher risk of SMs relative to the general population, and an AER of 102.69 per 10,000. Although the exact mechanism is unclear, the risk of SM development may be due to genetic predisposition, immune dysregulation, or treatment-induced immune suppression.

Survival trends in young patients with Waldenström macroglobulinemia: Over five decades of experience

Waldenström macroglobulinemia (WM) is a rare, indolent lymphoma, that predominately affects the elderly. We report the outcomes of young WM patients, evaluated over five decades, compared to their older counterparts, matched for the time of diagnosis. Between January 1, 1960 and October 31, 2013, 140 (11.8%) WM patients were ≤50 years of age at diagnosis in our database, and their estimated 10-year overall survival (OS) was 74%, with death attributable to WM in a higher proportion of patients compared to their older (≥65 years) counterparts (91% vs. 58%, p = .0001). Young patients were grouped into three cohorts based on the timing of the initiation of therapy: Group 1 (1960-1977, n = 12), Group 2 (1978-1995, n = 48), and Group 3 (1996-2013, n = 74). Among young patients, there was no disease-specific survival (DSS) difference across the three periods, [median DSS at 13 years (95% CI 5-23), 16 years (95% CI 14-22), and 15 years (95% CI 10-NR; p = .41), respectively]. However, DSS for the older cohort incrementally improved (Group 1, median 5.2 years, Group 2: 9.6 years, Group 3: 12 years; p = .05) over these periods. The estimated average years-of-life lost for the young cohort was 11.2 years from diagnosis, based on the expected survival for a normal age- and sex-matched population. Despite a protracted disease course, nearly all young patients succumb to their disease. In contrast to the improved survival of the elderly patient population, the evolving treatment strategies in WM have not impacted the outcome of young patients; however, the impact of Bruton tyrosine kinase inhibitors on this unique patient population remains to be determined.

The epidemiology of Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare subtype of non-Hodgkin lymphoma characterized by the presence of lymphoplasmacytic lymphoma (LPL) in the bone marrow accompanied by a monoclonal immunoglobulin type M (IgM) in the serum. WM was first described only 80 years ago and became reportable in the US as a malignancy in 1988. Very little systematic research was conducted prior to 2000 to characterize incidence, clinical characteristics, risk factors or diagnostic and prognostic criteria, and there were essentially no WM-specific clinical interventional trials. Since the inaugural meeting of the International Workshop in Waldenström's Macroglobulinemia (IWWM) in 2000, WM has become the focus of a steadily increasing and productive body of research, engaging a growing number of investigators throughout the world. This introductory overview provides summary of the current understanding of the epidemiology of WM/LPL as a backdrop for a series of consensus panel recommendations arising from research presented at the 11th IWWM.

[Waldenström disease: News and perspectives in 2022]

Waldenström's disease is a B-cell neoplasm characterized by the accumulation of lymphoplasmacytic cells (LPCs) in the bone marrow, and more rarely in the lymph nodes and the spleen, which produce a monoclonal immunoglobulin M (IgM) protein. The diagnosis requires the identification of LPCs in the bone marrow, using specific markers in flow cytometry. The MYD88L265P mutation is found in 95% of cases and the CXCR4 mutation in 30-40% of cases. These markers must be sought because they have a diagnostic and prognostic role, and they might become predictive in the future. The clinical presentation is very variable, and includes anomalies related to the bone marrow infiltration of the LPCs (such as anemia), but also anomalies of the physico-chemical and/or immunological activity of the overproduced IgM (hyperviscosity, AL amyloidosis, cryoglobulinemia, anti-MAG neuropathies, etc.). Prognostic scores (IPSSWM) now make it possible to understand the prognosis of symptomatic WM requiring appropriate treatment. The therapeutic management depends on many parameters, such as the specific clinical presentation, the speed of evolution and of course the age and comorbidities. Immuno-chemotherapy is often the 1st line treatment (rituximab-cyclophosphamide-dexamethasone (RCD) or bendamustine-rituximab (BR)) but the role of targeted therapies is becoming preponderant. Bruton tyrosine kinase inhibitors (BTKi) are used today in first relapse. Other therapeutic perspectives will certainly allow us tomorrow to better understand this incurable chronic disease, such as new generations of BTKi, BCL2 inhibitors, anti-CXCR4, bi-specific antibodies, and CAR-T cells.

The Spectrum of Ocular Manifestations in Patients with Waldenström's Macroglobulinemia

PURPOSE

To investigate the ocular manifestations in 91 Waldenström's macroglobulinemia (WM) patients.

METHODS

Retrospective, cross-sectional, observational analysis.

RESULTS

Ocular impairments, detected in 19 patients, included flame-shaped hemorrhages, venous sausaging, papilledema, macular detachments, or central retinal vein occlusion in 16 patients; paraproteinemic keratopathy in 2; and a CANOMAD syndrome in 1. Best-corrected visual acuity was ≥0.5 logMAR units in 11 of 38 eyes. Intraocular pressure was increased in seven eyes. Genetic analysis in seven patients showed a mutation in the MYD88 gene in six patients and a nonsense mutation in the CXCR4 gene in five patients. Plasmapheresis followed by chemotherapy with or without the addition of rituximab resulted in improvement or normalization of the ophthalmological findings in 15 patients.

CONCLUSION

The ocular manifestations of WM are protean and potentially sight threatening. Recent advances in genomic profiling and chemotherapy have remarkably improved the hematological and ophthalmological outcomes of these patients.

Co-Binding of JQ1 and Venetoclax Exhibited Synergetic Inhibitory Effect for Cancer Therapy; Potential Line of Treatment for the Waldenström Macroglobulinemia Lymphoma

In recent times, the development of combination therapy has been a focal point in drug discovery. This article explores the potential synergistic effect of co-administration of Bcl2 inhibitor Venetoclax and BET inhibitor JQ1. We envisioned that the 'dual-site'-binding of Bcl2 has significant prospects and paves the way for the next round of rational design of potent Waldenström macroglobulinemia (WM) therapy. The preferential binding mechanisms of the multi-catalytic sites of the Bcl2 enzyme have been a subject of debate in the literature. This study conducted a systematic procedure to explore the preferred binding modes and the structural effects of co-binding at each catalytic active site. Interestingly, a mutual enhanced binding effect was observed - Venetoclax increased the binding affinity of JQ1 by 11.5 %, while JQ1 boosted the binding affinity of Venetoclax by 16.3 % when compared with individual inhibition of each drug. This synergistic binding effect has significantly increased protein stability, with substantial correlated movements and multiple van der Waals interactions. The structural and thermodynamic insights unveiled in this report would assist the future design of improved combined therapy against WM.

Zanubrutinib in Treating Waldenström Macroglobulinemia, the Last Shall Be the First

In Waldenström macroglobulinemia (WM), a lymphoplasmacytic lymphoma characterized by monoclonal immunoglobulin M (IgM) gammopathy, aberrant Bruton tyrosine kinase (BTK) signaling has been identified as one mechanism of pathogenesis. For this reason, selective BTK inhibiting therapies have emerged as an attractive option for treatment within the therapeutic landscape also comprising chemotherapy, monoclonal antibodies, proteasome inhibitors, and B-cell lymphoma 2 (BCL2) inhibitors. The first BTK inhibiting therapy, ibrutinib, showed great efficacy in treating WM. However, response rates were dependent on whether patients had the CXCR4 mutation, a molecular aberration that may confer resistance to BTK inhibitors. Furthermore, ibrutinib’s toxicities, most notably hypertension and atrial arrhythmia, led to dose reductions or discontinuation. The toxicity profile of ibrutinib can be attributed to the inhibition of additional kinases that are structurally related to BTK. Therefore, the next-generation highly selective zanubrutinib was developed to address the concerns regarding toxicity and tolerance related to ibrutinib therapy. Based on the results of the randomized, open-label Phase 3 ASPEN (NCT03053440) trial, the Food and Drug Administration (FDA) approved zanubrutinib for treating WM. This trial directly compared zanubrutinib to ibrutinib in patients with treatment-naïve or relapsed/refractory WM, and the results showed stronger responses with zanubrutinib. More importantly, patients responded strongly to zanubrutinib therapy regardless of CXCR4 mutation status. Additionally, zanubrutinib was associated with fewer grade 3 or higher toxicities and was generally better tolerated. Another Phase 1/2 study has been conducted with just zanubrutinib in WM showcasing high efficacy with few toxicities as well. Even though zanubrutinib has been the third and last BTK inhibitor to currently penetrate the market for B-cell lymphoproliferative malignancies, we highlight the emergence of zanubrutinib as a key player in the forefront of the therapeutic landscape in WM.

Concurrent Waldenstrom’s Macroglobulinemia and Myelodysplastic Syndrome with a Sequent t(10;13)(p13;q22) Translocation

Myelodysplastic syndromes (MDS) and Waldenstrom’s macroglobulinemia (WM) are rarely synchronous. Ineffective myelopoiesis/hematopoiesis with clonal unilineage or multilineage dysplasia and cytopenias characterize MDS. Despite a myeloid origin, MDS can sometimes lead to decreased production, abnormal apoptosis or dysmaturation of B cells, and the development of lymphoma. WM includes bone marrow involvement by lymphoplasmacytic lymphoma (LPL) secreting monoclonal immunoglobulin M (IgM) with somatic mutation (L265P) of myeloid differentiation primary response 88 gene (MYD88) in 80–90%, or various mutations of C-terminal domain of the C-X-C chemokine receptor type 4 (CXCR4) gene in 20–40% of cases. A unique, progressive case of concurrent MDS and WM with several somatic mutations (some unreported before) and a novel balanced reciprocal translocation between chromosomes 10 and 13 is presented below.

SOHO State of the Art Updates and Next Questions: Waldenström Macroglobulinemia - 2021 Update on Management and Future Directions

Waldenstrom macroglobulinemia (WM) is a low-grade B-cell lymphoproliferative disorder. It is defined by having ≥ 10% bone marrow infiltration with lymphoplasmacytic cells and/or an immunoglobulin M (IgM) monoclonal gammopathy of ≥3g/dL. Risk factors include a personal history of IgM MGUS, and a family history of WM or a related disorder. Race, sex, and chronic antigen stimulation also appear to influence risk. Between 93 to 97% of patients with WM have a somatic mutation of the MYD88 gene. Of these, approximately 30% also have a mutation of CXCR4. The presence of a MYD88 mutation is associated with higher 10-year overall survival (90% vs. 73%; P < .001), while CXCR4 mutation status does not appear to have a similar effect. Based on consensus guidelines, WM patients with a disease-related hemoglobin level of less than 10g/dL, a platelet count of less than 100×10 9/L, bulky adenopathy or organomegaly, symptomatic hyperviscosity, severe neuropathy, amyloidosis, cryoglobulinemia, cold agglutinin disease, or evidence of disease transformation, should be considered for immediate therapy. Patients not meeting these criteria may be observed, with monitoring at 3 to 6 month intervals. When treatment is warranted, combinations of rituximab with alkylating agents and proteasome inhibitors are often effective, as are Bruton's tyrosine kinase (BTK) inhibitors and BCL-2 inhibitors. Selection among available regimens should take patients' gene mutation profile, disease-related features, and co-morbid conditions into account. Promising novel therapies in development include non-covalent BTK inhibitors, CXCR4 antagonists, BCL 2 inhibitors, bi-specific antibodies, radioimmunoconjugates, and CD19- and CD20-Targeted Chimeric Antigen Receptor T cells.

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.

Differential Diagnosis of Waldenström's Macroglobulinemia and Early Management: Perspectives from Clinical Practice

Waldenström's Macroglobulinemia (WM) is a clonal B-lymphocyte neoplasm characterized by the presence of IgM monoclonal protein and ≥10% bone marrow involvement with lymphoplasmacytic cells. Several mature B-cell and plasma cell disorders can potentially produce monoclonal IgM immunoglobulin and hence, careful consideration of the differential diagnosis is vital. Clinico-pathological features, immunophenotype, and MYD88 mutation status help distinguish WM from other plasma cell and lymphoproliferative disorders. Treatment is only indicated in patients symptomatic from adenopathy or organomegaly, neuropathy, hyper viscosity, cryoglobulinemia, cold agglutinin disease, cytopenia's or amyloidosis. Alkylators (cyclophosphamide, bendamustine) in combination with anti-CD20 antibodies and novel targeted agents including Bruton tyrosine kinase (BTK) inhibitors like ibrutinib are the mainstay of frontline treatment in symptomatic WM.

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.

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.

Screening and identification of a novel FHL2 mutation by whole exome sequencing in twins with familial Waldenström macroglobulinemia

BACKGROUND

Waldenström macroglobulinemia (WM) is a rare chronic B-cell lymphoma. Familial clustering of WM has been observed over the years. However, little is known about the contribution of inherited genetic variants to familial WM cases.

METHODS

The authors performed whole exome sequencing (WES) of germline DNA samples from twins, one diagnosed with WM and the other diagnosed with immunoglobulin M monoclonal gammopathy of undetermined significance, and their healthy siblings. Bioinformatics analysis of public biological databases was used to identify the most relevant familial WM candidate from WES. Transcript expression and protein levels of the familial WM candidate were evaluated in the WM patient and 2 unaffected members of the kindred.

RESULTS

Among the 10 shared candidate mutations in the twins, the authors identified a novel heterozygous germline mutation in four and a half LIM domains protein 2 (FHL2; c.G226A, p.V76M) as a familial WM-associated mutation. FHL2 appeared to be connected with reported signaling pathways and disease-driving genes such as IL6 and HCK in WM. In addition, the authors found reduced FHL2 messenger RNA and protein expression in peripheral blood samples from the patient with WM in comparison with the healthy siblings.

CONCLUSIONS

Taken together, these findings indicate that an FHL2^g226a mutation may play an important role in familial WM, and they provide new screening possibilities for familial cases.

LAY SUMMARY

Familial clustering in Waldenström macroglobulinemia (WM) has been observed over the years. The authors performed whole exome sequencing of germline DNA samples from twins, one diagnosed with WM and the other diagnosed with immunoglobulin M monoclonal gammopathy of undetermined significance, and their healthy siblings. Among the 10 shared candidate mutations in the twins, a novel heterozygous germline mutation in four and a half LIM domains protein 2 (FHL2; c.G226A, p.V76M) was identified as the most relevant familial WM candidate through bioinformatics analysis of a public database. Also, messenger RNA and protein expression of FHL2 was significantly lower in peripheral blood mononuclear cells of the WM patient in comparison with the healthy siblings, and this suggested that the function of FHL2 was impaired when mutated.

Molecular and genetic biomarkers implemented from next-generation sequencing provide treatment insights in clinical practice for Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a distinct type of indolent lymphoplasmacytic lymphoma (LPL) with a high frequency of MYD88^L265P mutation. Treatment for WM/LPL is highly variable in clinic and ibrutinib (a Bruton tyrosine kinase inhibitor, BTKi) has become a new treatment option for WM. To investigate the clinical impact of genetic alterations in WM, we assembled a large cohort of 219 WMs and 12 LPLs dividing into two subcohorts: a training cohort, patients sequenced by a same targeted 29-gene next-generation sequencing (NGS) panel, and a validation cohort, patients sequenced by allele specific-PCR or other targeted NGS panels. In both training and validation subcohorts, MYD88^L265P and TP53 mutations showed favorable and adverse prognostic effects, respectively. CXCR4 nonsense/missense mutations (CXCR4^NS/MS), cytogenetic complex karyotypes, and a family history of lymphoma/leukemia in first-degree relatives were associated with significantly worse clinical outcomes only or more in the validation subcohort. We further investigated the efficacy of various treatments and interaction with genetic factors in the entire cohort. Upfront dexamethasone usage was associated with poorer clinical outcomes in patients who received non-proteasome-containing chemotherapy as first-line treatment independent of genetic factors. Maintenance rituximab was associated with better survival. Ibrutinib/BTKi showed potential benefit in relapsed/refractory patients and patients without CXCR4^NS/MS including those with TP53 mutations. In conclusion, genetic testing for MYD88^L265P, TP53, and CXCR4 mutations and cytogenetic analysis provide important information for prognosis prediction and therapy selection. The findings in these study are valuable for improving treatment decisions on therapies available for WM/LPL patients with integration of NGS in clinic.

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.

Current and novel BTK inhibitors in Waldenström's macroglobulinemia

The current therapeutic approach in Waldenström’s macroglobulinemia (WM) is being driven by insights in disease biology and genomic landscape. Bruton’s tyrosine kinase (BTK) plays a key role in signaling pathways for the survival of WM clone. BTK inhibition has changed the treatment landscape of the disease. Ibrutinib has resulted in deep and durable responses both as an upfront and salvage treatment with a manageable toxicity profile. However, the need for fewer off-target effects and deeper responses has resulted in the clinical development of second-generation BTK inhibitors. Zanubrutinib has resulted in clinically meaningful antitumor activity, including deep and durable responses, with a low discontinuation rate due to treatment-related toxicities. Cardiovascular adverse events seem to be milder compared with ibrutinib. Interestingly, the efficacy of zanubrutinib in WM is significant both for MYD88^L265P and MYD88^WT patients. Although the randomized, phase III ASPEN clinical trial did not meet its primary endpoint in terms of showing a superiority of zanubrutinib in deep responses compared with ibrutinib, secondary efficacy and safety endpoints underscore the potential clinical role of zanubrutinib in the treatment algorithm of WM independent of the MYD88 mutational status. Combination regimens and non-covalent BTK inhibitors are emerging as promising treatment strategies. Long-term data will determine whether next-generation BTK inhibitors are more potent and safer compared with ibrutinib, and whether they are able to overcome resistance to ibrutinib, either alone or in combination with inhibitors of other interrelated molecular pathways.

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.

6q deletion in Waldenström macroglobulinaemia negatively affects time to transformation and survival

Deletion of the long arm of chromosome 6 (del6q) is the most frequent cytogenetic abnormality in Waldenström macroglobulinaemia (WM), occurring in approximately 50% of patients. Its effect on patient outcome has not been completely established. We used fluorescence in situ hybridisation to analyse the prevalence of del6q in selected CD19+ bone marrow cells of 225 patients with newly diagnosed immunoglobulin M (IgM) monoclonal gammopathies. Del6q was identified in one of 27 (4%) cases of IgM-monoclonal gammopathy of undetermined significance, nine of 105 (9%) of asymptomatic WM (aWM), and 28/93 (30%) of symptomatic WM (sWM), and was associated with adverse prognostic features and higher International Prognostic Scoring System for WM (IPSSWM) score. Asymptomatic patients with del6q ultimately required therapy more often and had a shorter time to transformation (TT) to symptomatic disease (median TT, 30 months vs. 199 months, respectively, P < 0·001). When treatment was required, 6q-deleted patients had shorter progression-free survival (median 20 vs. 47 months, P < 0·001). The presence of del6q translated into shorter overall survival (OS), irrespective of the initial diagnosis, with a median OS of 90 compared with 131 months in non-del6q patients (P = 0·01). In summary, our study shows that del6q in IgM gammopathy is associated with symptomatic disease, need for treatment and poorer clinical outcomes.

The current role of BTK inhibitors in the treatment of Waldenstrom's Macroglobulinemia

INTRODUCTION

Waldenstrom's Macroglobulinemia (WM) is a rare, indolent lymphoplasmacytic lymphoma characterized by heterogeneous clinical and genomic profile. Bruton's tyrosine kinase (BTK) is central to the signaling pathways required for clonal WM cell survival, and BTK inhibitors currently have an imperative role in the treatment of WM.

AREAS COVERED

The central role of BTK in WM will be described, and the rationale behind the development of BTKi. Clinical trial data that led to the approval of ibrutinib (the first-in-class BTKi) will be reviewed. Despite its potency and safe toxicity profile, ibrutinib does not induce deep remissions, and responses are mutational-status dependent. The mechanisms that lead to resistance to this agent are being investigated. Ibrutinib treatment has to be continuous; consequently, patients face the effects of long-term toxicity. In that context, second-generation inhibitors are in clinical development with fewer off-target effects and an efficacy profile, which will be determined based on long-term follow-up data.

EXPERT OPINION

The optimal therapeutic approach for WM patients remains to be established. The question of whether a combinatory (or synergistic) regimen to overcome resistance and allow for a fixed treatment duration will allow for deep and durable response is being addressed in ongoing clinical trials.

[Bilateral occlusion of retinal vessels in Waldenstrom's disease (a case study)]

The article describes a clinical case of bilateral occlusion of retinal vessels in a patient with Waldenstrom's disease - a rare lymphoplasmocytic tumor of the bone marrow characterized by a complex of syndromes, among which the syndrome of blood hyperviscosity dominates. Comprehensive clinical, instrumental and laboratory examinations revealed that besides the syndrome of blood hyperviscosity the patient also had loci of cerebral ischemia (according to magnetic resonance imaging), ocular hypoperfusion with severe deficiency of retinal and choroidal blood flow (according to Doppler methods) indicating the presence of ocular ischemic syndrome. Since bilateral occlusion of retinal vessels without concomitant vascular and/or systemic pathology is rare, patients with such diagnosis should be referred to a hematologist.

How I treat Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is an uncommon lymphoma characterized by the infiltration of the bone marrow by clonal lymphoplasmacytic cells that produce monoclonal immunoglobulin M (IgM). The disease may have an asymptomatic phase, or patients may present with symptoms and complications resulting from marrow or other tissue infiltration, or from physicochemical or immunological properties of the monoclonal IgM. Diagnosis of WM has been clearly defined, and genetic testing for somatic mutation of MYD88L265P is a useful tool for differential diagnosis from other conditions. Specific criteria that define symptomatic disease that needs treatment offer clinical guidance. The treatment of WM has evolved rapidly, with treatment options that include anti-CD20 monoclonal antibody-based combinations and BTK inhibitors. The choice of therapy is based on the need for rapid disease control, presence of specific disease complications, and patient's age. With the use of BTK inhibitors, the use of continuous therapy has been introduced as another option over fixed-duration chemoimmunotherapy. In this review, we focus on different clinical scenarios and discuss treatment options, based on the available data.

Schnitzler's syndrome - a novel hypothesis of a shared pathophysiologic mechanism with Waldenström's disease

Schnitzler’s syndrome is an auto-inflammatory disorder which is characterized by two mandatory features: an urticarial rash and a monoclonal gammopathy. Although the pathophysiology of this syndrome is not yet fully understood, a role for interleukin-1 seems apparent. While this presumed link between interleukin-1 and the monoclonal gammopathy is not yet elucidated, a mutual factor in pathophysiology however seems likely. Here we present a novel hypothesis of a shared pathophysiologic mechanism between Schitzler’s syndrome and monoclonal gammopathy.

How we manage patients with Waldenström macroglobulinaemia

Waldenström macroglobulinaemia (WM) is a rare, indolent B-cell lymphoproliferative disorder characterized by cellular involvement in bone marrow and monoclonal IgM production. Symptoms can be related to cytopenias, tumoural involvement, or IgM-related disorders. Somatic mutations in the MYD88 gene have been described in the majority of WM cases. The mutation is responsible for a gain-of-function and induces activation of nuclear factor-κB, for DNA transcription and cell survival. It seems that MYD88 mutation is associated with better prognosis and better response to some treatment. Treatments are started when WM is symptomatic, following systematic biological and morphological assessments. Therapeutic choice depends on age, frailty and urgent efficacy need. In first line, the majority of patients are treated with monoclonal anti-CD20 antibody-based regimens combined with cytotoxic chemotherapy. Rituximab, cyclophosphamide and dexamethasone remain the most commonly used regimen with good safety. Nevertheless, increasing numbers of new drugs are becoming available or are in development. Proteasome inhibitors, such as bortezomib or carfilzmib, showed good and rapid responses. Bruton tyrosine kinase (BTK) inhibitor demonstrated excellent results and is now available for relapse/refractory disease or as first line for some patients. This review highlights the diagnostic procedures and therapeutic approaches in WM.

Waldenstrom's Macroglobulinemia: An Update

Waldenstrom Macroglobulinemia is a rare lymphoproliferative disorder with distinctive clinical features. Diagnostic and prognostic characterisation in WM significantly changed with the discovery of two molecular markers: MYD88 and CXCR4. Mutational status of these latter influences both clinical presentation and prognosis and demonstrated therapeutic implications. Treatment choice in Waldenstrom disease is strictly guided by patients age and characteristics, specific goals of therapy, the necessity for rapid disease control, the risk of treatment-related neuropathy, disease features, the risk of immunosuppression or secondary malignancies and potential for future autologous stem cell transplantation. The therapeutic landscape has expanded during the last years and the approval of ibrutinib, the first drug approved for Waldenstrom Macroglobulinemia, represents a significant step forward for a better management of the disease.

Waldenstrom's Macroglobulinemia: An Update

Waldenstrom Macroglobulinemia is a rare lymphoproliferative disorder with distinctive clinical features. Diagnostic and prognostic characterisation in WM significantly changed with the discovery of two molecular markers: MYD88 and CXCR4. Mutational status of these latter influences both clinical presentation and prognosis and demonstrated therapeutic implications. Treatment choice in Waldenstrom disease is strictly guided by patients age and characteristics, specific goals of therapy, the necessity for rapid disease control, the risk of treatment-related neuropathy, disease features, the risk of immunosuppression or secondary malignancies and potential for future autologous stem cell transplantation. The therapeutic landscape has expanded during the last years and the approval of ibrutinib, the first drug approved for Waldenstrom Macroglobulinemia, represents a significant step forward for a better management of the disease.

Pattern of somatic mutations in patients with Waldenström macroglobulinemia or IgM monoclonal gammopathy of undetermined significance

We analyzed MYD88 and CXCR4 mutation status of 260 patients with Waldenström macroglobulinemia or IgM monoclonal gammopathy of undetermined significance using allele-specific real time quantitative polymerase chain reaction and Sanger sequencing, respectively. A subgroup of 119 patients was further studied with next-generation sequencing of 11 target genes (MYD88, CXCR4, ARID1A, KMT2D, NOTCH2, TP53, PRDM1, CD79B, TRAF3, MYBBP1A, and TNFAIP3). MYD88 (L265P) was found at diagnosis in 91% of patients with Waldenström macroglobulinemia and in 60% of patients with IgM monoclonal gammopathy of undetermined significance using allele-specific polymerase chain reaction analysis. MYD88 mutations other than the classical L265P (V217F, S219C and M232T) were found in four cases by next-generation sequencing. Waldenström macroglobulinemia patients with wild-type MYD88 had a distinct clinical phenotype characterized by less bone marrow infiltration (P=0.01) and more frequent extramedullary involvement (P=0.001) compared to patients with mutated MYD88. Patients with wild-type MYD88 did not show additional mutations in the other target genes. CXCR4 mutations were found by Sanger sequencing in 22% of patients with Waldenström macroglobulinemia. With next-generation sequencing, a CXCR4 mutation was detected in 23% of patients with Waldenström macroglobulinemia and 9% of those with IgM monoclonal gammopathy of undetermined significance. Asymptomatic Waldenström macroglobulinemia patients harboring a CXCR4 mutation had a shorter treatment-free survival (51 months) than that of patients with wild-type CXCR4 (median not reached) (P=0.007). Analysis of variant allele frequencies indicated that CXCR4 mutations were present in the dominant clone in the majority of cases. Recurrent somatic mutations of KMT2D were found in 24% of patients with Waldenström macroglobulinemia and 5% of patients with IgM monoclonal gammopathy of undetermined significance and were primarily subclonal.

Current options to manage Waldenström's macroglobulinemia

INTRODUCTION

Waldenström's macroglobulinemia (WM) is a rare, incurable B-cell lymphoma, with a median survival of 5-10 years in symptomatic patients. There is no consensus on the standard of care and several agents are currently used in these patients. Areas covered: In this article, we will review the use of standard therapies and new drugs investigated such as monoclonal antibodies, proteasome inhibitors, immunomodulatory agents, Bruton's tyrosine kinase inhibitors and novel agents in early-stage development. Expert commentary: RCD (Rituximab/Cyclophosphamide/Dexamethasone) is an effective and safe treatment in first line in WM. BR (Bendamustine/Rituximab) or BRD (Bortezomib/Rituximab/Dexamethasone) provide durable responses, and are still indicated in most patients. Ibrutinib is a new option and it was approved as primary therapy and for relapse. Carfilzomib based therapy represents an emerging option for proteasome-inhibitor based therapy for WM. Despite encouraging results, WM remains an incurable disease; therefore, new treatment options are needed. For this reason, continued participation in clinical trials should be encouraged.

Waldenström Macroglobulinemia: Review of Pathogenesis and Management

Waldenström macroglobulinemia (WM) is a low-grade B-cell clonal disorder characterized by lymphoplasmacytic bone marrow involvement associated with monoclonal immunoglobulin M. Although WM remains to be an incurable disease with a heterogeneous clinical course, the recent discovery of mutations in the MYD88 and CXCR4 genes further enhanced our understanding of its pathogenesis. Development of new therapies including monoclonal antibodies, proteasome inhibitors, and Bruton tyrosine kinase inhibitors have made the management of WM increasingly complex. Treatment should be tailored to the individual patient while considering many clinical factors. The clinical outcomes are expected to continue to improve, given the emergence of novel therapeutics and better understanding of the underlying pathogenesis.

Genomics, Signaling, and Treatment of Waldenström Macroglobulinemia

Next-generation sequencing has revealed recurring somatic mutations in Waldenström macroglobulinemia (WM). Commonly recurring mutations include MYD88 (95% to 97%), CXCR4 (30% to 40%), ARID1A (17%), and CD79B (8% to 15%). Diagnostic discrimination of WM from overlapping B-cell malignancies is aided by MYD88 mutation status. Transcription is affected by MYD88 and CXCR4 mutations and includes overexpression of genes involved in VDJ recombination, CXCR4 pathway signaling, and BCL2 family members. Among patients with MYD88 mutations, those with CXCR4 mutations show transcriptional silencing of tumor suppressors associated with acquisition of mutated MYD88. Deletions involving chromosome 6q are common and include genes that modulate nuclear factor-κB, BCL2, BTK, apoptosis, differentiation, and ARID1B. Non-chromosome 6q genes are also frequently deleted and include LYN, a regulator of B-cell receptor signaling. MYD88 and CXCR4 mutations affect WM disease presentation and treatment outcome. Patients with wild-type MYD88 show lower bone marrow disease burden and serum immunoglobulin M levels but show an increased risk of death. Patients with CXCR4 mutations have higher bone marrow disease burden, and those with nonsense CXCR4 mutations have higher serum immunoglobulin M levels and incidence of symptomatic hyperviscosity. Mutated MYD88 triggers BTK, IRAK1/IRAK4, and HCK growth and survival signaling, whereas CXCR4 mutations promote AKT and extracellular regulated kinase-1/2 signaling and drug resistance in the presence of its ligand CXCL12. Ibrutinib is active in patients with WM and is affected by MYD88 and CXCR4 mutation status. Patients with mutated MYD88 and wild-type CXCR4 mutation status exhibit best responses to ibrutinib. Lower response rates and delayed responses to ibrutinib are associated with mutated CXCR4 in patients with WM. MYD88 and CXCR4 mutation status may be helpful in treatment selection for symptomatic patients. Novel therapeutic approaches under investigation include therapeutics targeting MYD88, CXCR4, and BCL2 signaling.

Waldenström macroglobulinemia: biology, genetics, and therapy

Waldenström macroglobulinemia (WM) is a distinct clinicopathologic entity characterized by the presence of a lymphoplasmacytic lymphoma, a non-Hodgkin lymphoma, and IgM monoclonal gammopathy. WM is an indolent, uncommon malignancy mostly affecting the elderly. Patient outcomes have modestly improved since the introduction of rituximab to conventional cytotoxic chemotherapy more than 20 years ago. However, the pivotal discovery of the somatic MYD88 L265P mutation, harbored by most patients with WM, and the somatic CXCR4 WHIM mutations, similar to germline CXCR4 mutations seen in the warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis (WHIM) syndrome, present in approximately one-third of patients with WM, has fundamentally changed our understanding of this disease and expanded the potential therapeutic targets. Within this new paradigm, ibrutinib emerged as a promising new drug. Ibrutinib targets Bruton’s tyrosine kinase, a downstream protein in the B-cell receptor pathway that is overactivated by the MYD88 L265P mutation. A seminal Phase II trial of ibrutinib in previously treated WM patients showed impressive response rates and confirmed the effects of MYD88 L265P and CXCR4 WHIM mutations in response to therapy. Ibrutinib is the first and only US Food and Drug Administration–approved drug specifically for the treatment of WM. However, before ibrutinib can be established as the standard of care for WM, long-term data regarding efficacy and safety are required. Further research to address ibrutinib resistance and cost-effectiveness is also imperative before ibrutinib can gain widespread acceptance. This review will cover the present pathophysiologic understanding of WM in light of the recent MYD88 and CXCR4 discovery, as well as current and emergent treatment regimens with focus on ibrutinib.

Transcriptome sequencing reveals a profile that corresponds to genomic variants in Waldenström macroglobulinemia

Whole-genome sequencing has identified highly prevalent somatic mutations including MYD88, CXCR4, and ARID1A in Waldenström macroglobulinemia (WM). The impact of these and other somatic mutations on transcriptional regulation in WM remains to be clarified. We performed next-generation transcriptional profiling in 57 WM patients and compared findings to healthy donor B cells. Compared with healthy donors, WM patient samples showed greatly enhanced expression of the VDJ recombination genes DNTT, RAG1, and RAG2, but not AICDA Genes related to CXCR4 signaling were also upregulated and included CXCR4, CXCL12, and VCAM1 regardless of CXCR4 mutation status, indicating a potential role for CXCR4 signaling in all WM patients. The WM transcriptional profile was equally dissimilar to healthy memory B cells and circulating B cells likely due increased differentiation rather than cellular origin. The profile for CXCR4 mutations corresponded to diminished B-cell differentiation and suppression of tumor suppressors upregulated by MYD88 mutations in a manner associated with the suppression of TLR4 signaling relative to those mutated for MYD88 alone. Promoter methylation studies of top findings failed to explain this suppressive effect but identified aberrant methylation patterns in MYD88 wild-type patients. CXCR4 and MYD88 transcription were negatively correlated, demonstrated allele-specific transcription bias, and, along with CXCL13, were associated with bone marrow disease involvement. Distinct gene expression profiles for patients with wild-type MYD88, mutated ARID1A, familial predisposition to WM, chr6q deletions, chr3q amplifications, and trisomy 4 are also described. The findings provide novel insights into the molecular pathogenesis and opportunities for targeted therapeutic strategies for WM.

Exome sequencing reveals recurrent germ line variants in patients with familial Waldenström macroglobulinemia

Familial aggregation of Waldenström macroglobulinemia (WM) cases, and the clustering of B-cell lymphoproliferative disorders among first-degree relatives of WM patients, has been reported. Nevertheless, the possible contribution of inherited susceptibility to familial WM remains unrevealed. We performed whole exome sequencing on germ line DNA obtained from 4 family members in which coinheritance for WM was documented in 3 of them, and screened additional independent 246 cases by using gene-specific mutation sequencing. Among the shared germ line variants, LAPTM5(c403t) and HCLS1(g496a) were the most recurrent, being present in 3/3 affected members of the index family, detected in 8% of the unrelated familial cases, and present in 0.5% of the nonfamilial cases and in <0.05 of a control population. LAPTM5 and HCLS1 appeared as relevant WM candidate genes that characterized familial WM individuals and were also functionally relevant to the tumor clone. These findings highlight potentially novel contributors for the genetic predisposition to familial WM and indicate that LAPTM5(c403t) and HCLS1(g496a) may represent predisposition alleles in patients with familial WM.

Waldenström's macroglobulinemia: a clinical perspective in the era of novel therapeutics

Waldenström's macroglobulinemia (WM) is a rare, low-grade malignancy with no established standard of care. Rituximab regimens are most commonly used, supported by their efficacy in hematologic malignancies, including WM. A growing number of investigational regimens for WM have been evaluated in phase II clinical trials, including single-agent and combination strategies that include newer-generation monoclonal antibodies (ofatumumab and alemtuzumab), proteasome inhibitors (bortezomib and carfilzomib), immunomodulatory agents (thalidomide and lenalidomide), phosphoinositide 3-kinase/protein kinase B (Akt)/mammalian target of rapamycin pathway inhibitors (everolimus and perifosene), a Bruton's tyrosine kinase inhibitor (ibrutinib), and a histone deacetylase inhibitor (panobinostat). Other novel agents are in early-stage development for WM. International treatment guidelines for WM suggest suitable regimens in the newly diagnosed and relapsed/refractory settings, in accordance with patient age, disease presentation, and efficacy and safety profiles of particular drugs. These factors must be considered when choosing appropriate therapy for individual patients with WM, to maximize response and prolong survival, while minimizing the risk of adverse events. This review article provides a clinical perspective of the modern management of patients with WM, in the context of available trial data for novel regimens and recently updated treatment guidelines.

Waldenstrom Macroglobulinemia: Genomic Aberrations and Treatment

Waldenström macroglobulinemia (WM) is a rare, indolent, and monoclonal immunoglobulin M-associated lymphoplasmacytic disorder with unique clinicopathologic characteristics. Over the past decade, remarkable progress has occurred on both the diagnostic and therapeutic fronts in WM. A deeper understanding of the disease biology emanates from the seminal discoveries of myeloid differentiation primary response 88 (MYD88) L265P somatic mutation in the vast majority of cases and C-X-C chemokine receptor, type 4, mutations in about a third of patients. Although WM remains an incurable malignancy, and the indications to initiate treatment are largely unchanged, the therapeutic armamentarium continues to expand. Acknowledging the paucity of high-level evidence from large randomized controlled trials, herein, we evaluate the genomic aberrations and provide a strategic framework for the management in the frontline as well as the relapsed/refractory settings of symptomatic WM.

Familial Waldenstrom's macroglobulinemia and relation to immune defects, autoimmune diseases, and haematological malignancies--A population-based study from northern Sweden

BACKGROUND

Waldenstrom's macroglobulinemia (WM) is a rare lymphoprolipherative disorder with geographic and ethnic disparities in incidence. The cause of WM remains mostly unknown although a role for genetic, immune-related, and environmental factors has been suggested. Most cases of WM are sporadic although familial cases occur.

AIM

This study estimated the incidence of WM in northern Sweden and identified and described patients with familial WM in this area.

PATIENTS AND METHODS

The Swedish and Northern Lymphoma Registry, the Swedish Cancer Registry (1997-2011), and medical records were used to identify patients with WM in two counties (Norrbotten and Västerbotten) in northern Sweden and to calculate the overall age-adjusted incidence (2000-2012). We identified 12 families with a family history of WM, IgM monoclonal gammophathy (MGUS), and/or multiple myeloma (MM).

RESULTS

In Norrbotten and Västerbotten, the age-adjusted incidence of WM/LPL is 1.75 and 1.48 per 100,000 persons per year, respectively (2000-2012), rates that are higher than the overall incidence of WM/LPL in Sweden (1.05 per 100,000 persons per year; 2000-2012). Autoimmune diseases and other haematological malignancies in the medical history (their own or in relatives) were reported in 9/12 and 5/12 families, respectively. A high proportion of abnormal serum protein electrophoresis was found in the relatives; 12/56 (21%) had a MGUS and 13/56 (25%) showed abnormalities in the immunoglobulin levels (i.e. subnormal levels and poly/oligoclonality).

CONCLUSION

The incidence of WM in Norrbotten and Västerbotten counties was higher than expected. We found a strong correlation between autoimmune/inflammatory diseases, other haematological malignancies, and familial WM and a high frequency of serum immunoglobulin abnormalities in the relatives of the WM patients, findings that strengthen the hypothesis that the aetiology of WM depends on both immune-related and genetic factors.

Rare Circulating Cells in Familial Waldenström Macroglobulinemia Displaying the MYD88 L265P Mutation Are Enriched by Epstein-Barr Virus Immortalization

The MYD88 L265P is a recurrent somatic mutation in neoplastic cells from patients with Waldenström Macroglobulinemia (WM). We identified the MYD88 L265P mutation in three individuals from unrelated families, but its presence did not explain the disease segregation within these WM pedigrees. We observed the mutation in these three individuals at high allele fractions in DNA extracted from EBV-immortalized Lymphoblastoid cell lines established from peripheral blood (LCL), but at much lower allele fractions in DNA extracted directly from peripheral blood, suggesting that this mutation is present in a clonal cell subpopulation rather than of germ-line origin. Furthermore, we observed that the MYD88 L265P mutation is enriched in WM families, detected in 40.5% of patients with familial WM or MGUS (10/22 WM, 5/15 MGUS), compared to 3.5% of patients with familial MM or MGUS (0/72 MM, 4/41 MGUS) (p = 10-7). The mutant allele frequency increased with passages in vitro after immortalization with Epstein-Barr virus (EBV) consistent with the MYD88 L265P described gain-of-function proposed for this mutation. The MYD88 L265P mutation appears to be frequently present in circulating cells in patients with WM, and MGUS, and these cells are amenable to immortalization by EBV.