Diagnosis and management of Waldenstrom's macroglobulinemia

An unusual case of Waldenstrom's macroglobulinemia presented with nasopharyngeal involvement

We report a rare case of a 68-year-old male who presented with fever, weight loss, nasal blockage, and epistaxis. Examination revealed cervical and axillary lymphadenopathy with no evidence of organomegaly. On evaluation, bone marrow aspiration showed lymphoplasmacytic infiltration. The computed tomography of the neck showed nasopharyngeal mass and the biopsy of this mass and cervical lymph node showed lymphoplasmacytic lymphoma (LPL) with high serum IgM level. Hence, a diagnosis of Waldenstrom’s macroglobulinemia (WM) was made. The patient received six cycles of chemotherapy with a combination of cyclophosphamide, vincristine, and prednisolone (COP regimen). Currently, the patient is under follow-up and in complete remission (CR), one year after completion of therapy. Nasopharyngeal involvement is extremely rare in WM, and hence we report this case.

Primary therapy of Waldenstrom macroglobulinemia (WM) with weekly bortezomib, low-dose dexamethasone, and rituximab (BDR): long-term results of a phase 2 study of the European Myeloma Network (EMN)

In this phase 2 multicenter trial, we evaluated the activity of bortezomib, dexamethasone, and rituximab (BDR) combination in previously untreated symptomatic patients with Waldenström macroglobulinemia (WM). To prevent immunoglobulin M (IgM) "flare," single agent bortezomib (1.3 mg/m(2) IV days 1, 4, 8, and 11; 21-day cycle), was followed by weekly IV bortezomib (1.6 mg/m(2) days 1, 8, 15, and 22) every 35 days for 4 additional cycles, followed by IV dexamethasone (40 mg) and IV rituximab (375 mg/m(2)) in cycles 2 and 5. Fifty-nine patients were treated; 45.5% and 40% were high and intermediate risk per the International Prognostic Scoring System for WM. On intent to treat, 85% responded (3% complete response, 7% very good partial response, 58% partial response [PR]). In 11% of patients, an increase of IgM ≥25% was observed after rituximab; no patient required plasmapheresis. After a minimum follow-up of 32 months, median progression-free survival was 42 months, 3-year duration of response for patients with ≥PR was 70%, and 3-year survival was 81%. Peripheral neuropathy occurred in 46% (grade ≥3 in 7%); only 8% discontinued bortezomib due to neuropathy. BDR is rapidly acting, well tolerated, and nonmyelotoxic, inducing durable responses in previously untreated WM.

Incidence of lymphoplasmacytic lymphoma/Waldenström's macroglobulinaemia in Japan and Taiwan population-based cancer registries, 1996-2003

Few studies have investigated the incidence rate of lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM) in Asian populations. We assessed the incidence of LPL/WM using data from 13 population-based cancer registries in Japan and data from the Taiwan National Cancer registry. During 1996-2003, a total of 280 new cases of LPL/WM were recorded in Japan and 56 were recorded in Taiwan, with the median age at diagnosis being 73 and 67 years, respectively. The incidence of LPL/WM showed male predominance in both countries. Crude age-specific incidence rates increased sharply with age in both countries, especially in people >65 years. Age-standardized (to the World standard population) incidence rates per 100,000 person-years were 0.043 (0.071 for men and 0.023 for women) and 0.031 (0.041 for men and 0.020 for women) in Japan and Taiwan, respectively. Age-standardized (to the 2,000 US standard population) incidence rates in Japan and Taiwan were lower than rates reported in the literature for Asians living in the United State. A significant increasing trend was observed in the incidence over the period from 1996 to 2003 in Japan alone. This report suggests that both environmental and/or genetic factors may be involved in LPL/WM development.

Histidine based adsorbents for selective removal of monoclonal immunoglobulin IgM antibodies from Waldenstrom's macroglobulinemia patient sera: a preliminary study

Waldenstrom's macroglobulinemia (WM) is considered by the Revised European American Lymphoma (REAL) and World Health Organization (WHO) as a clinical lympho plasmacytic syndrome associated with high monoclonal (IgM) secretion. The hyper viscosity syndrome is associated with several clinical disorders of monoclonal IgM. Patients with clinical symptoms of hyper viscosity should be treated with plasma pheresis, which is limited by its non-selective removal of all plasma components. These limitations have steered efforts to find a more specific removal according to clinical needs and avoiding plasma components replacement. Removal by specific adsorption is the most powerful selective apheresis technique. The active adsorbed ligand is covalently bound to an insoluble matrix through which plasma is passed. Amino acids have been introduced as ligands in clinical apheresis for the removal of auto antibodies associated with autoimmune diseases. The present preliminary study describes the binding of monoclonal IgM antibodies from sera of patients with WM, on histidine immobilized to activated sepharose. The advantages of efficient binding and elution, suggest histidine adsorbents as prospective clinical means suitable for the removal of monoclonal IgM from sera of patients diagnosed with WM. The advantages of efficient adsorption and elution, non toxicity of histidine, good selectivity, good stability, as well as their low cost strongly suggest histidine adsorbents as prospective clinical means suitable for the removal of monoclonal IgM from sera of patients diagnosed with WM.

The bone marrow microenvironment in waldenstrom macroglobulinemia

Waldenstrom macroglobulinemia (WM) is a low-grade B-cell lymphoproliferative disorder characterized primarily by specific homing and growth of tumor cells within the bone marrow niches. The progressive growth of tumor cells throughout the bone marrow indicates that the tumor cells are capable of homing and adhering to specific niches that allow growth, survival and drug resistance. In this review we highlight the interaction of the tumor cells in WM and the bone marrow microenvironment including bone marrow stromal cells, endothelial cells and mast cells. Migration, adhesion and downstream activation of signaling pathways leads to cell trafficking and cell dissemination in WM. Future therapeutic agents need to target not only the tumor clone, but also its close interaction with the bone marrow microenvironment.

Etiology of Waldenström macroglobulinemia: genetic factors and immune-related conditions

Epidemiologic studies provide an insight into the etiology of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia, which indicates that repetitive immune stimulation and genetic factors play an important role. Here, the current understanding on the causes of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia are reviewed. Recent studies of the literature are discussed, and future population-based studies are proposed to further elucidate the molecular mechanisms that underlie these associations. Finally, the clinical implications of these data are outlined, and perspectives on clinical follow-up and counseling are provided.

Serous macular detachment in Waldenström macroglobulinemia: a report of four cases

PURPOSE

To describe a series of 4 patients with Waldenström macroglobulinemia and serous macular detachment, and propose a mechanism for development of subretinal fluid based on optical coherence tomography (OCT) findings.

DESIGN

Retrospective observational case series.

METHODS

The records of patients with Waldenström macroglobulinemia and OCT documentation of serous macular detachment at Wills Eye Institute were reviewed. Data collection included clinical examination, as well as findings on fluorescein angiography (FA) and OCT.

RESULTS

Four patients (8 eyes) with Waldenström macroglobulinemia and serous retinal detachment were identified. All eyes had varying degrees of venous stasis retinopathy and intraretinal edema overlying the macular detachment. Three patients had no FA leakage, while 1 patient had macular leakage in a petaloid pattern. Focal outer retinal defects within the detached retina were seen in 4 eyes on OCT imaging. In one eye, development of cystoid macular edema was observed before the outer retinal defect and serous macular detachment. All patients with serous macular detachment had some degree of outer retinal disruption.

CONCLUSION

Discontinuity of the outer retina within the macular detachment may enable immunoglobulins along with accumulated intraretinal fluid to flow into the subretinal space, creating a serous retinal detachment. Even with systemic treatment of the underlying Waldenström macroglobulinemia, the visual prognosis was guarded.

Development and characterization of a novel human Waldenström macroglobulinemia cell line: RPCI-WM1, Roswell Park Cancer Institute - Waldenström Macroglobulinemia 1

Understanding the biology of Waldenström macroglobulinemia is hindered by a lack of preclinical models. We report a novel cell line, RPCI-WM1, from a patient treated for WM. The cell line secretes human immunoglobulin M (h-IgM) with κ-light chain restriction identical to the primary tumor. The cell line has a modal chromosomal number of 46 and harbors chromosomal changes such as deletion of 6q21, monoallelic deletion of 9p21 (CDKN2A), 13q14 (RB1) and 18q21 (BCL-2), with a consistent amplification of 14q32 (immunoglobulin heavy chain; IgH) identical to its founding tumor sample. The clonal relationship is confirmed by identical CDR3 length and single nucleotide polymorphisms as well as a matching IgH sequence of the cell line and founding tumor. Both also harbor a heterozygous, non-synonymous mutation at amino acid 265 in the MYD88 gene (L265P). The cell line expresses most of the cell surface markers present on the parent cells. Overall, RPCI-WM1 represents a valuable model to study Waldenström macroglobulinemia.

Results of a phase 2 trial of the single-agent histone deacetylase inhibitor panobinostat in patients with relapsed/refractory Waldenström macroglobulinemia

The present study aimed to determine the safety and activity of the histone deacetylase inhibitor panobinostat in patients with relapsed/refractory Waldenström macroglobulinemia (WM). Eligibility criteria included patients with relapsed/refractory WM with any number of prior therapies. Patients received panobinostat at 30 mg 3 times a week; 12 of 36 (33%) patients were enrolled at 25 mg dose. A total of 36 patients received therapy. The median age was 62 years (range, 47-80) and the median number of prior therapies was 3 (range, 1-8). All of the patients had received prior rituximab. Minimal response (MR) or better was achieved in 47% of patients (90% confidence interval [CI], 33-62), with 22% partial remissions and 25% MR. In addition, 18 (50%) patients achieved stable disease and none showed progression while on therapy. The median time to first response was 1.8 months (range, 1.7-3.2). The median progression-free survival was 6.6 months(90% CI, 5.5-14.8). Grade 3 and 4 toxicities included thrombocytopenia (67%), neutropenia (36%), anemia (28%), leukopenia (22%), and fatigue (11%). We conclude that panobinostat is an active therapeutic agent in patients with relapsed/ refractory WM. This study (www.clinicaltrials.gov identifier: NCT00936611) establishes a role for histone deacetylase inhibitors as an active class of therapeutic agents in WM.

Are you sure this is Waldenström macroglobulinemia?

Waldenström macroglobulinemia (WM) is a rare lymphoproliferative disorder characterized by the presence of lymphoplasmacytic cells in the BM and IgM monoclonal protein in the serum. The origin of the malignant clone is thought to be a B cell arrested after somatic hypermutation in the germinal center and before terminal differentiation to plasma cells. In this review, recent advances in the genetic and epigenetic regulators of tumor progression are discussed. Risk factors include IgM-monoclonal gammopathy of undermined significance, familial disease, and immunological factors. The clinical manifestations of the disease include those related to clonal infiltration of the BM, lymph nodes, and, rarely, other sites such as pulmonary or CNS infiltration (Bing-Neel syndrome). Other manifestations are related to the IgM monoclonal protein, including hyperviscosity, cryoglobulinemia, protein-protein interactions, Ab-mediated disorders such as neuropathy, hemolytic anemia, and Schnitzler syndrome. IgM deposition in organs can lead to amyloidogenic manifestations in WM. The diagnostic workup for a patient with WM and rare presentations of WM are described herein. Prognosis of WM depends on 5 major factors in the International Staging System, including age, anemia, thrombocytopenia, β-2 microglobulin, and IgM level. The differential diagnosis of WM includes IgM-multiple myeloma, marginal zone lymphoma, mantle cell lymphoma, and follicular lymphoma.

Waldenström's macroglobulinemia harbors a unique proteome where Ku70 is severely underexpressed as compared with other B-lymphoproliferative disorders

Waldenström's macroglobulinemia (WM) is a clonal B-cell lymphoproliferative disorder (LPD) of post-germinal center nature. Despite the fact that the precise molecular pathway(s) leading to WM remain(s) to be elucidated, a hallmark of the disease is the absence of the immunoglobulin heavy chain class switch recombination. Using two-dimensional gel electrophoresis, we compared proteomic profiles of WM cells with that of other LPDs. We were able to demonstrate that WM constitutes a unique proteomic entity as compared with chronic lymphocytic leukemia and marginal zone lymphoma. Statistical comparisons of protein expression levels revealed that a few proteins are distinctly expressed in WM in comparison with other LPDs. In particular we observed a major downregulation of the double strand repair protein Ku70 (XRCC6); confirmed at both the protein and RNA levels in an independent cohort of patients. Hence, we define a distinctive proteomic profile for WM where the downregulation of Ku70—a component of the non homologous end-joining pathway—might be relevant in disease pathophysiology.

Successful treatment of γ-heavy-chain disease with rituximab and fludarabine

An 84-year-old Japanese man was admitted because of pancytopenia. The bone marrow was hypoplastic with a predominance of abnormal small lymphocytes and grape cells, which were positive for CD19 and CD20, and partially for the surface ĸ-light chain. Systemic CT scanning showed neither lymph node swelling nor hepatosplenomegaly. Serum immunoelectrophoresis and rocket immunoselection assays showed the presence of monoclonal IgG protein without a corresponding light chain and faint IgMĸ monoclonal protein. Histologic analysis of the clot preparation of the bone marrow aspirate facilitated a diagnosis of lymphoplasmacytic lymphoma (LPL). PCR analysis of the marrow cells demonstrated a clonal rearrangement of the immunoglobulin heavy-chain gene. From these results, we made a final diagnosis of γ-heavy-chain disease (γ-HCD) with underlying LPL localized in the bone marrow. We performed only a single course of immunochemotherapy (rituximab and fludarabine) in view of severely impaired hematopoiesis, which resulted in marked reduction of lymphoma cells and improvement of hematopoiesis. This report suggests the efficacy of rituximab plus fludarabine therapy for LPL-associated γ-HCD.

Novel diagnostic approaches in Bing-Neel syndrome

The central nervous system (CNS) manifestations of Waldenström's macroglobulinemia (WM) are known as the Bing-Neel syndrome (BNS). Patients with BNS can be classified into Group A and Group B based on the presence of lymphoplasmacytoid (LMP) cells within the brain parenchyma, leptomeninges, dura, and/or cerebrospinal fluid (CSF). To identify characteristic imaging findings for both Group A and Group B patients, we reviewed all 36 cases (26 referenced, 10 unreported) of proven WM with CNS symptoms, CSF analysis and/or biopsy, and magnetic resonance imaging (MRI) of the brain and/or spinal cord. Enhancement on MRI suggests invasion of the central neuraxis by LMP cells, and can help distinguish between Group A and Group B patients. In addition to differentiating true WM lesions in the CNS from ischemia, hyperviscosity events, and demyelinating lesions, evaluation of brain and spinal cord with gadolinium-enhanced MRI has the potential to guide management.

Recovery of kidney function by rituximab-based therapy in a patient with Waldenström's macroglobulinemia-related nephropathy presenting cast nephropathy and interstitial lymphocytic infiltration

A 60-year-old man with Waldenström's macroglobulinemia (WM) was admitted to our hospital for evaluation of rapid progressive renal deterioration despite 3 cycles of oral melphalan and prednisolone (MP) therapy. Renal biopsy just before introducing hemodialysis revealed cast nephropathy and severe tubulo-interstitial infiltration of B lymphocytes. After 6 cycles of rituximab, cyclophosphamide, vincristine and prednisolone (R-COP) therapy, his renal function improved enough to discontinue hemodialysis. This is a rare case of WM-related renal involvement caused by both monoclonal protein and tumor infiltration and, to our knowledge, the second report on improved renal function by rituximab-based therapy.

Development of diffuse large B-cell lymphoma in a patient with Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma: clonal identity between two B-cell neoplasms

Waldenström's macroglobulinemia (WM)/ lymphoplasmacytic lymphoma (LPL) is an indolent mature B-cell neoplasm. In rare cases of WM/LPL, diffuse large B-cell lymphoma (DLBCL) develops as a result of histologic transformation. In this report, we present a case of DLBCL developing in a patient with WM/LPL. Combination chemotherapy for DLBCL was effective and complete remission was eventually achieved. We attempted to determine the clonal relatedness between WM/LPL and DLBCL in the patient by analyzing complementarity-determining region 3 (CDR3) in the immunoglobulin heavy chain gene. A common CDR3 sequence was found in tumor cells of DLBCL and those of WM/LPL, indicating that tumor cells of DLBCL are clonally identical to those of WM/LPL. Therefore, in the present case, DLBCL is developed from WM/LPL cells by clonal evolution.

Distinctive clinical and histological features of Waldenström's macroglobulinemia and splenic marginal zone lymphoma

We studied 122 patients with Waldenström's macroglobulinemia (WM) and 98 with splenic marginal zone lymphoma (SMZL); 29 SMZL patients (30%) had a serum MC (IgM in 17 patients). SMZL differed from WM for female prevalence, abdominal and superficial adenopathy, spleen and liver involvement, positive HCV. The median MC level was 2.0 g/dL in WM and 0.95 g/dL in SMZL (P<.001). On BM histology, SMZL was characterized by sinusoidal infiltration (70% of cases) and by a more frequent nodular pattern (P<.01) while WM had a higher incidence of interstitial BM localization. After a median follow-up of 5.3 years, median OS was not reached for SMZL and was 12 years for WM (P=.23; 14 years for asymptomatic WM, 8 years for symptomatic WM). In conclusion, despite similar outcomes of these 2 entities, SMZL appears as a disease with distinct clinical features and BM histology and a peculiar association with HCV infection.

Histone deacetylase inhibitors demonstrate significant preclinical activity as single agents, and in combination with bortezomib in Waldenström's macroglobulinemia

We studied the role of histone deacetylase inhibitors in Waldenstrom's macroglobulinemia (WM). Gene expression profiling of bone marrow CD19+ cells from 30 patients and 10 healthy donors showed overexpression of HDAC4, HDAC9, and Sirt5, with validation of HDAC9 overexpression by q-PCR in primary and BCWM.1 cells. Suberoylanilide hydroxamic acid, trichostatin A, panobinostat, and sirtinol demonstrated dose-dependent killing of BCWM.1 cells. TSA showed the greatest potency with IC50 of 70 nM. Importantly, HDAC9 activity was decreased following TSA treatment suggesting an essential role for this HDAC in WM therapy. The combination of bortezomib plus HDAC inhibitors resulted in at least additive tumor cell killing in BCWM.1 cells. TSA and bortezomib-induced apoptosis depended on a similar set of caspase activation, whereas their effect on cell cycle regulators was distinctly different. These results provided a framework for examining HDAC inhibitors as monotherapy, as well as combination therapy with bortezomib in WM.

Development of diffuse large B-cell lymphoma in a patient with Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma: clonal identity between two B-cell neoplasms

Waldenström's macroglobulinemia (WM)/ lymphoplasmacytic lymphoma (LPL) is an indolent mature B-cell neoplasm. In rare cases of WM/LPL, diffuse large B-cell lymphoma (DLBCL) develops as a result of histologic transformation. In this report, we present a case of DLBCL developing in a patient with WM/LPL. Combination chemotherapy for DLBCL was effective and complete remission was eventually achieved. We attempted to determine the clonal relatedness between WM/LPL and DLBCL in the patient by analyzing complementarity-determining region 3 (CDR3) in the immunoglobulin heavy chain gene. A common CDR3 sequence was found in tumor cells of DLBCL and those of WM/LPL, indicating that tumor cells of DLBCL are clonally identical to those of WM/LPL. Therefore, in the present case, DLBCL is developed from WM/LPL cells by clonal evolution.

Emerging drugs for Waldenström's macroglobulinemia

INTRODUCTION

Waldenström's macroglobulinemia (WM) is a rare but distinct B-cell lymphoproliferative disorder characterized by lymphoplasmacytic bone marrow infiltration and IgM monoclonal paraproteinemia. Alkylators or nucleosides analogs, often in combination with rituximab, are the most commonly used drugs, but WM will relapse and even salvage treatments may fail.

AREAS COVERED

We present recent advances on the treatment of WM, focusing on drugs that are under clinical investigation and for which data indicate promising activity and positive future prospects. Bortezomib is a proteasome inhibitor that eventually becomes a major treatment option for WM. Everolimus and perifosine which target mTOR (mammalian target of rapamycin) and Akt, respectively, of the PI3K/AKT/mTOR pathway showed some activity. Bendamustine, a novel alkylating agent is active, especially in combination with rituximab. Immunomodulatory drugs can act synergistically with rituximab but are toxic. Targeting surface antigens of the lymphoplasmatic cells have shown promising results.

EXPERT OPINION

Combinations of novel drugs with established agents are feasible and increase response rates but whether there will be an increase in the survival of patients with WM needs further investigation. The toxicity profile is an important determinant for the feasibility of these drugs in patients with WM.

No significant improvement in the outcome of patients with Waldenström's macroglobulinemia treated over the last 25 years

The treatment of Waldenström's macroglobulinemia (WM) has changed over the last decades, mainly because of the introduction of nucleoside analogues and of rituximab while novel agents such as bortezomib have been recently introduced. We performed an analysis to investigate whether the outcome of patients with WM has improved over the last years, compared to that of patients who started treatment before new drugs became widely available, especially as part of the frontline treatment. We analyzed 345 symptomatic patients with WM: 130 who initiated treatment before and 215 who started treatment after January 1, 2000. Patients who started treatment in the latter group were older and had more often elevated beta2-microglobulin but the other characteristics were similar between the two groups. Most patients who started treatment before January 1, 2000 were treated upfront with alkylating agent-based regimens and most patients who started treatment after January 1, 2000 received rituximab-based regimens as initial treatment. Objective response (63 and 59%, respectively) and median overall survival, OS, (106.5 months for Group A and is estimated at 94 months for Group B, P = 0.327) were similar. There was also no difference regarding OS or cause specific survival (CSS) in each risk group according to IPSSWM. Our observation may be explained by the indolent course of WM in several patients and by the lack of profound cytoreduction in patients with high-risk disease. Possible differences in the 15- or 20-year survival rate between the two groups may be detected with further follow-up of these patients.

Prognostication of the high-risk WM patient

Waldenström's macroglobulinemia is characterized by a protracted course in most patients and the median survival may be long. However, a subset of patients may present with more aggressive disease that is associated with short survival. In order to better characterize these "poor-risk" patients, we identified patients who died within 2 years from the initiation of front-line treatment. These patients were older and had more often features of aggressive disease, such as elevated LDH and low serum albumin than the standard-risk population. Furthermore, only a minority of poor-risk patient had a response to initial therapy. However, conventional clinical factors or even the lack on response could not adequately identify poor-risk patients, indicating the need for novel molecular or other markers that would be able to effectively recognize patients at greatest need for aggressive therapies.

Residual monotypic plasma cells in patients with waldenstrom macroglobulinemia after therapy

Waldenström macroglobulinemia (WM) is currently defined as lymphoplasmacytic lymphoma involving bone marrow (BM) associated with a serum IgM paraprotein. WM is typically composed of small lymphocytes, plasmacytoid lymphocytes, and plasma cells in variable proportions, which can change after therapy. In this study, we assessed 41 WM cases that required chemotherapy, 39 showing persistent disease in restaging BM specimens. In 10 cases, there was persistent monotypic plasmacytosis in BM in the absence of demonstrable monotypic B cells. The monotypic plasma cells represented 0.5% to 46% of the cellularity and persisted 1 to 50 months after the last course of chemotherapy. The plasma cells were best quantified by immunohistochemical analysis on paraffin sections. We conclude that WM can persist as a pure plasma cell population after therapy. This finding has implications for the immunophenotypic assessment of WM after therapy and may explain persistent IgM paraproteinemia in patients with WM with no evidence of a clonal B-lymphocyte population.

Novel agents in Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a B-cell disorder characterized by the infiltration of the bone marrow with lymphoplasmacytic cells and the detection of an IgM monoclonal gammopathy in the serum. WM is considered an incurable disease, with a median overall survival of 87 months. The success of targeted therapy in multiple myeloma has led to the development and investigation of more than 30 new compounds in this disease and in other plasma cell dyscrasias, including WM, both in the preclinical settings and as part of clinical trials. Among therapeutic options, first-line therapies have been based on single-agent or combination regimens with alkylator agents, nucleoside analogues and the monoclonal antibody anti-CD20. Based on the understanding of the complex interaction between WM tumor cells and the bone marrow microenvironment, and the signaling pathways that are deregulated in WM pathogenesis, a number of novel therapeutic agents are now available and have demonstrated significant efficacy in WM. The range of the overall response rate for these novel agents is between 25 and 96%. Ongoing and planned future clinical trials include those using protein kinase C inhibitors such as enzastaurin, new proteasome inhibitors such as carfilzomib, histone deacetylase inhibitors such as LBH589, humanized CD20 antibodies such as ofatumumab and additional alkylating agents such as bendamustine. These agents, when compared with traditional chemotherapeutic agents, may lead in the future to higher responses, longer remissions and better quality of life for patients with WM. This article will mainly focus on those novel agents that have entered clinical trials for the treatment of WM.

Peripheral capillary non-perfusion in asymptomatic Waldenström's macroglobulinemia

Background

To report the rare association of peripheral retinal ischemia in a patient with Waldenström's macroglobulinemia.

Case Presentation

A 39-year old man with a recent diagnosis of asymptomatic Waldenström's macroglobulinemia (WM) was referred from his physician for ocular evaluation. The fundus examination in his right eye (RE) revealed very mild central vein dilation, while retinal hemorrhages associated with microaneurismal alterations of the vascular plexus were detected at the temporal periphery. Fluoroscein angiography of his RE revealed an extended area of capillary dropout distal to the microaneurismal lesions. In our patient with WM an extensive area of capillary non-perfusion, in the absence of severe involvement of the posterior pole was documented; this association to the best of our knowledge has never been reported before.

Conclusion

Although the incidence of the disease is rare, meticulous examination of the retinal periphery should be performed in all patients with WM and vice versa the differential diagnosis of peripheral retinal ischemia of unknown origin should include an investigation to rule out asymptomatic Waldenström's macroglobulinemia.

Allogeneic stem-cell transplantation in patients with Waldenström macroglobulinemia: report from the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

PURPOSE

Allogeneic stem-cell transplantation (alloSCT) is a curative therapeutic option for patients with low-grade lymphoid malignancies. Information regarding alloSCT in Waldenström macroglobulinemia (WM) is limited. This study presents the long-term outcome of a large series of patients with WM treated with alloSCT.

PATIENTS AND METHODS

A total of 86 patients received allograft by using either myeloablative (MAC; n = 37) or reduced-intensity conditioning (RIC; n = 49) regimens and were retrospectively studied. The median age was 49 years (range, 23 to 64 years); 47 patients had received three or more previous lines of therapy, and eight patients had experienced failure on a prior autologous stem-cell transplantation. A total of 59 patients (68.6%) had chemotherapy-sensitive disease at the time of alloSCT. Median follow-up of the surviving patients was 50 months (7 to 142 months).

RESULTS

Nonrelapse mortality (NRM) at 3 years was 33% for MAC and 23% for RIC. The overall response rate was 75.6%. The relapse rates (RRs) at 3 years were 11% for MAC and 25% for RIC. Fourteen patients received donor lymphocyte infusions (DLIs) for disease relapse. PFS and OS at 5 years were 56% and 62% for MAC and 49% and 64% for RIC, respectively. The occurrence of chronic graft-versus-host disease (cGVHD) was associated with a higher NRM and a lower RR, leading to an improvement in PFS.

CONCLUSION

alloSCT can induce durable remissions in a selected population of young and heavily pretreated patients with WM. The low RR, the achievement of additional disease responses after DLIs, and the lower RR in patients developing cGVHD suggest the existence of a clinically relevant graft-versus-WM effect.

Phase II trial of weekly bortezomib in combination with rituximab in untreated patients with Waldenström Macroglobulinemia

This study aimed to determine the activity and safety of weekly bortezomib and rituximab in patients with untreated Waldenström Macroglobulinemia (WM). Patients with no prior therapy and symptomatic disease were eligible. Patients received bortezomib IV weekly at 1.6 mg/m(2) on days 1, 8, 15, q 28 days × 6 cycles, and rituximab 375 mg/m(2) weekly on cycles 1 and 4. Primary endpoint was the percent of patients with at least a minor response (MR). Twenty-six patients were treated. At least MR was observed in 23/26 patients (88%) (95% CI: 70-98%) with 1 complete response (4%), 1 near-complete response (4%), 15 partial remission (58%), and 6 MR (23%). Using IgM response evaluated by nephlometry, all 26 patients (100%) achieved at least MR or better. The median time to progression has not been reached, with an estimated 1-year event free rate of 79% (95% CI: 53, 91%). Common grade 3 and 4 therapy related adverse events included reversible neutropenia in 12%, anemia in 8%, and thrombocytopenia in 8%. No grade 3 or 4 neuropathy occurred. The combination of weekly bortezomib and rituximab exhibited significant activity and minimal neurological toxicity in patients with untreated WM.

Diagnosis and management of Waldenström macroglobulinemia: Mayo stratification of macroglobulinemia and risk-adapted therapy (mSMART) guidelines

Waldenström macroglobulinemia is a B-cell malignancy with lymphoplasmacytic infiltration in the bone marrow or lymphatic tissue and a monoclonal immunoglobulin M protein (IgM) in the serum. It is incurable with current therapy, and the decision to treat patients as well as the choice of treatment can be complex. Using a risk-adapted approach, we provide recommendations on timing and choice of therapy. Patients with smoldering or asymptomatic Waldenström macroglobulinemia and preserved hematologic function should be observed without therapy. Symptomatic patients with modest hematologic compromise, IgM-related neuropathy that requires therapy, or hemolytic anemia unresponsive to corticosteroids should receive standard doses of rituximab alone without maintenance therapy. Patients who have severe constitutional symptoms, profound hematologic compromise, symptomatic bulky disease, or hyperviscosity should be treated with the DRC (dexamethasone, rituximab, cyclophosphamide) regimen. Any patient with symptoms of hyperviscosity should first be treated with plasmapheresis. For patients who experience relapse after a response to initial therapy of more than 2 years' duration, the original therapy should be repeated. For patients who had an inadequate response to initial therapy or a response of less than 2 years' duration, an alternative agent or combination should be used. Autologous stem cell transplant should be considered in all eligible patients with relapsed disease.

Clinical features and treatment outcomes of lymphoplasmacytic lymphoma: a single center experience in Korea

Lymphoplasmacytic lymphoma (LPL) constitutes less than 5% of all non-Hodgkin lymphomas, and little is known about clinical features and treatment outcomes for patients with LPL in East Asia. In this study, we summarize our experiences managing patients diagnosed with LPL in Korea. A retrospective analysis was performed using data for 22 patients with LPL diagnosed at Samsung Medical Center. LPL was more common among males (77.3%), with a median age of diagnosis of 63 years (range 26-86). The most common presenting symptom was fatigue related to anemia (59.1%), and the bone marrow was commonly involved at diagnosis (90.9%). IgM paraproteinemia was found in 15 patients, and only one patient had anti-hepatitis C virus. Although some patients could be observed without treatment, the majority of patients required systemic treatment. Chlorambucil alone and cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) or CHOP-like combination chemotherapy was frequently used as a first-line treatment, and a fludarabine-based regimen was commonly used as salvage therapy. However, responses to those treatments were not satisfactory. Even patients who could be monitored without therapy became refractory to salvage therapies once their disease progressed. Eight patients died due to disease progression, and the median overall survival was 70.8 months (95% CI: 31.4-109.2 months). This study describes the clinical features and treatment outcome of LPL in Korea. The treatment approach was too heterogeneous to draw firm conclusions, however, and treatment recommendations in the future should utilize a uniform treatment strategy.

High-dose therapy and autologous stem-cell transplantation in Waldenstrom macroglobulinemia: the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

PURPOSE

The role of autologous stem-cell transplantation (ASCT) in Waldenström macroglobulinemia (WM) is not defined. The aim of this study was to analyze the results of ASCT in patients with WM and to determine the prognostic factors that have a significant impact on outcome.

PATIENTS AND METHODS

We analyzed 158 adult patients with WM reported to the European Group for Blood and Marrow Transplantation (EBMT) between January 1991 and December 2005. Median time from diagnosis to ASCT was 1.7 years (range, 0.3 to 20.3 years), 32% of the patients experienced treatment failure with at least three lines of therapy, and 93% had sensitive disease at the time of ASCT. Conditioning regimen was total-body irradiation-based in 45 patients. Median follow-up for surviving patients was 4.2 years (range, 0.5 to 14.8 years).

RESULTS

Nonrelapse mortality was 3.8% at 1 year. Ten patients developed a secondary malignancy, with a cumulative incidence of 8.4% at 5 years. Relapse rate was 52.1% at 5 years. Progression-free survival (PFS) and overall survival were 39.7% and 68.5%, respectively, at 5 years and were significantly influenced by number of lines of therapy and chemorefractoriness at ASCT. The achievement of a negative immunofixation after ASCT had a positive impact on PFS after ASCT. When used as consolidation at first response, ASCT provided a PFS of 44% at 5 years.

CONCLUSION

ASCT is a feasible procedure in young patients with advanced WM. ASCT should not be offered to patients with chemoresistant disease and to those who received more than three lines of therapy.

Phase II trial of weekly bortezomib in combination with rituximab in relapsed or relapsed and refractory Waldenstrom macroglobulinemia

PURPOSE

This study aimed to determine activity and safety of weekly bortezomib and rituximab in patients with relapsed/refractory Waldenström macroglobulinemia (WM).

PATIENTS AND METHODS

Patients who had at least one previous therapy were eligible. All patients received bortezomib intravenously weekly at 1.6 mg/m(2) on days 1, 8, and 15, every 28 days for six cycles and rituximab 375 mg/m(2) weekly on cycles 1 and 4. The primary end point was the percentage of patients with at least a minor response.

RESULTS

Thirty-seven patients were treated. The majority of patients (78%) completed treatment per protocol. At least minimal response (MR) or better was observed in 81% (95% CI, 65% to 92%), with two patients (5%) in complete remission (CR)/near CR, 17 patients (46%) in partial response, and 11 patients (30%) in MR. The median time to progression was 16.4 months (95% CI, 11.4 to 21.1 months). Death occurred in one patient due to viral pneumonia. The most common grade 3 and 4 therapy-related adverse events included reversible neutropenia in 16%, anemia in 11%, and thrombocytopenia in 14%. Grade 3 peripheral neuropathy occurred in only two patients (5%). The median progression-free (PFS) is 15.6 months (95% CI, 11 to 21 months), with estimated 12-month and 18-month PFS of 57% (95% CI, 39% to 75%) and 45% (95% CI, 27% to 63%), respectively. The median overall survival has not been reached.

CONCLUSION

The combination of weekly bortezomib and rituximab showed significant activity and minimal neurologic toxicity in patients with relapsed WM.

Phase II trial of the oral mammalian target of rapamycin inhibitor everolimus in relapsed or refractory Waldenstrom macroglobulinemia

PURPOSE The phosphatidylinositol 3-kinase/mammalian target of rapamycin (mTOR) signal transduction pathway controls cell proliferation and survival. Everolimus is an oral agent targeting raptor mTOR (mTORC1). The trial's goal was to determine the antitumor activity and safety of single-agent everolimus in patients with relapsed/refractory Waldenström macroglobulinemia (WM). PATIENTS AND METHODS Eligible patients had measurable disease (immunoglobulin M monoclonal protein > 1,000 mg/dL with > 10% marrow involvement or nodal masses > 2 cm), a platelet count more than 75,000 x 10(6)/L, a neutrophil count more than 1,000 x 10(6)/L, and a creatinine and bilirubin less than 2 x the laboratory upper limit of normal. Patients received everolimus 10 mg orally daily and were evaluated monthly. Tumor response was assessed after cycles 2 and 6 and then every three cycles until progression. Results Fifty patients were treated. The median age was 63 years (range, 43 to 85 years). The overall response rate (complete response plus partial remission [PR] plus minimal response [MR]) was 70% (95% CI, 55% to 82%), with a PR of 42% and 28% MR. The median duration of response and median progression-free survival (PFS) have not been reached. The estimated PFS at 6 and 12 months is 75% (95% CI, 64% to 89%) and 62% (95% CI, 48% to 80%), respectively. Grade 3 or higher related toxicities were observed in 56% of patients. The most common were hematologic toxicities with cytopenias. Pulmonary toxicity occurred in 10% of patients. Dose reductions due to toxicity occurred in 52% of patients. CONCLUSION Everolimus has high single-agent activity with an overall response rate of 70% and manageable toxicity in patients with relapsed WM and offers a potential new therapeutic strategy for this patient group.

Clinical and translational studies of a phase II trial of the novel oral Akt inhibitor perifosine in relapsed or relapsed/refractory Waldenstrom's macroglobulinemia

BACKGROUND

Waldenström's macroglobulinemia (WM) is a rare, low-grade lymphoproliferative disorder. Based on preclinical studies, we conducted a phase II clinical trial testing the efficacy and safety of the Akt inhibitor perifosine in patients with relapsed/refractory WM.

PATIENTS AND METHODS

Thirty-seven patients were treated with oral perifosine (150 mg daily) for six cycles. Stable or responding patients were allowed to continue therapy until progression.

RESULTS

The median age was 65 years (range, 44-82). The median number of prior therapy lines was two (range, one to five). Of the 37 patients, 4 achieved partial response (11%), 9 minimal response (24%), and 20 showed stable disease (54%). The median progression-free survival was 12.6 months. Additionally, beta2 microglobulin of >3.5 mg/dL was associated with poor event-free survival (P = 0.002). Perifosine was generally well tolerated; adverse events related to therapy were cytopenias (grade 3-4, 13%), gastrointestinal symptoms (grade 1-2, 81%), and arthritis flare (all grades, 11%). Translational studies using gene expression profiling and immunohistochemistry showed that perifosine inhibited pGSK activity downstream of Akt, and inhibited nuclear factor kappaB activity.

CONCLUSION

Perifosine resulted in at least a minimal response in 35% of patients and a median progression-free survival of 12.6 months in patients with relapsed or relapsed/refractory WM, as well as in vivo inhibition of pGSK activity. The results of this study warrant further evaluation of perifosine in combination with rituximab or other active agents in patients with WM.

New Therapeutic Approaches for Waldenstrom Macroglobulinemia

Waldenstrom Macroglobulinemia (WM) is a B-cell disorder characterized by the infiltration of the bone marrow (BM) with lymphoplasmacytic cells, as well as detection of an IgM monoclonal gammopathy in the serum. WM is an incurable disease, with an overall medial survival of only 5-6 years. First-line therapy of WM has been based on single-agent or combination therapy with alkylator agents (e.g. chlorambucil or cyclophasphamide), nucleoside analogues (cladribine or fludarabine), and the monoclonal antibody rituximab. Novel therapeutic agents that have demonstrated efficacy in WM include thalidomide, lenalidomide, bortezomib, everolimus, Atacicept, and perifosine. The range of the ORR to these agents is between 25-80%. Ongoing and planned future clinical trials include those using PKC inhibitors such as enzastaurin, new proteasome inhibitors such as carfilzomib, histone deacetylase inhibitors such as panobinostat, humanized CD20 antibodies such as Ofatumumab, and additional alkylating agents such as bendamustine. These agents, when compared to traditional chemotherapeutic agents, may lead in the future to higher responses, longer remissions and better quality of life for patients with WM.

New Therapeutic Approaches for Waldenstrom Macroglobulinemia

Waldenstrom Macroglobulinemia (WM) is a B-cell disorder characterized by the infiltration of the bone marrow (BM) with lymphoplasmacytic cells, as well as detection of an IgM monoclonal gammopathy in the serum. WM is an incurable disease, with an overall medial survival of only 5-6 years. First-line therapy of WM has been based on single-agent or combination therapy with alkylator agents (e.g. chlorambucil or cyclophasphamide), nucleoside analogues (cladribine or fludarabine), and the monoclonal antibody rituximab. Novel therapeutic agents that have demonstrated efficacy in WM include thalidomide, lenalidomide, bortezomib, everolimus, Atacicept, and perifosine. The range of the ORR to these agents is between 25-80%. Ongoing and planned future clinical trials include those using PKC inhibitors such as enzastaurin, new proteasome inhibitors such as carfilzomib, histone deacetylase inhibitors such as panobinostat, humanized CD20 antibodies such as Ofatumumab, and additional alkylating agents such as bendamustine. These agents, when compared to traditional chemotherapeutic agents, may lead in the future to higher responses, longer remissions and better quality of life for patients with WM.

Novel therapeutic agents in Waldenström's macroglobulinemia

Within the past few years, major advances in the preclinical and clinical testing of novel therapeutic agents have occurred in Waldenström's macroglobulinemia (WM). These include agents that target the PI3K/Akt/mTOR pathway, PKC pathways, NF-kB signaling pathway, as well as tyrosine kinases and histone deacetylase inhibitors. In this review, we summarize the current understanding of the clinical development of these agents in WM.