Cladribine for Waldenström's macroglobulinaemia

Waldenström macroglobulinemia at 70

SUMMARY 

Over the last seven decades, Waldenström macroglobulinemia (WM) has changed from a clinical observation by an astute clinician to an uncommon, but well-defined clinical–pathologic entity. Similarly, therapeutic advances have evolved and now parallel our increasing understanding of the biology of WM. Very recently, the discovery of a highly prevalent somatic gene mutation has provided new understanding that challenges us to further individualize management of this disease. This article is intended to chronicle the 70-year development of our knowledge, treatment options and limitations that bring us to our current approach to WM, as well as the challenge for international collaboration in order to enable us to develop the most efficient path to optimal patient care.

Current and future therapeutic approach for Waldenström's macroglobulinemia

Waldenström's macroglobulinemia is a rare B-cell malignancy defined by medullar infiltration by clonal lymphoplasmocytic cells and monoclonal IgM secretion. Treatment is reserved for symptomatic patients. The main first-line treatment strategies combine immunotherapy (principally the anti-CD20 monoclonal antibody rituximab) with chemotherapeutic agents, including alkylating agents, purine analogs and/or bortezomib. The overall response rate to these conventional treatments is between 70 and 90%, but a cure cannot be expected. For patients with relapsed or refractory disease, drugs that were not used for first-line treatment and other agents such as immunomodulators can be tried, but the response rate is generally lower and the responses are shorter lived. Recently, advances in our understanding of the biology of Waldenström's macroglobulinemia have led to the development of new drugs targeting hyperactive pathways. This review focuses on current treatment options and on new therapeutic developments.

Advances in the treatment of Waldenström’s macroglobulinemia

Waldenström's macroglobulinemia is a distinct disorder characterized by a monoclonal immunoglobulin M paraprotein and morphological evidence of lymphoplasmacytic lymphoma. It is relatively rare, accounting for approximately 2% of all hematological malignancies. The aim of treatment for patients with Waldenström's macroglobulinemia should be to improve the quality and duration of life with minimal side effects in the most cost-effective manner. It is not yet clear if achievement of a complete remission confers clinical benefit and it is possible that prolonging therapy to maximal response may increase toxicity without extra benefit. Plasma exchange is indicated for the acute management of patients with severe problems due to a circulating paraprotein. There are no comparative data but alkylating agent-based treatments, combination therapy or purine analogs are all suitable choices for the initial therapy of patients requiring treatment. In younger patients, in whom high-dose treatment is contemplated, there is a role for the use of rituximab; however, it should be administered with caution in patients with high levels of immunoglobulin M paraprotein or signs of hyperviscosity because of the risk of 'flare' in the paraprotein level and consequent adverse clinical events.

Increased Incidence of Transformation and Myelodysplasia/Acute Leukemia in Patients With Waldenström Macroglobulinemia Treated With Nucleoside Analogs

Purpose

Nucleoside analogs (NAs) are considered as appropriate agents in the treatment of Waldenström macroglobulinemia (WM), a lymphoplasmacytic lymphoma. Sporadic reports on increased incidence of transformation to high-grade non-Hodgkin's lymphoma and development of therapy-related myelodysplasia/acute leukemia (t-MDS/AML) among patients with WM treated with NAs prompted us to examine the incidence of such events in a large population of patients with WM.

Patients and Methods

We examined the incidence of these events in 439 patients with WM, 193 and 136 of whom were previously treated with and without an NA, respectively, and 110 of whom had similar long-term follow-up without treatment. The median follow-up for all patients was 5 years.

Results

Overall, 12 patients (6.2%) either developed transformation (n = 9; 4.7%) or developed t-MDS/AML (n = 3; 1.6%) among NA-treated patients, compared with one patient (0.4%) who developed transformation in the non-NA treated group (P < .001); no such events occurred among untreated patients. Transformation and t-MDS/AML occurred at a median of 5 years from onset of NA therapy. The median survival of NA-treated patients who developed transformation did not differ from other NA-treated patients as a result of effective salvage treatment used for transformed disease. However, all NA-treated patients who developed t-MDS/AML died at a median of 5 months.

Conclusion

These data demonstrate an increased incidence of disease transformation to high-grade NHL and the development of t-MDS/AML among patients with WM treated with NAs.

Waldenstrom macroglobulinemia

In the past years, new developments have occurred both in the understanding of the biology of Waldenstrom Macroglobulinemia (WM) and in therapeutic options for WM. WM is a B-cell disorder characterized primarily by bone marrow infiltration with lymphoplasmacytic cells, along with demonstration of an IgM monoclonal gammopathy. Despite advances in therapy, WM remains incurable, with 5-6 years median overall survival of patients in symptomatic WM. Therapy is postponed for asymptomatic patients, and progressive anemia is the most common indication for initiation of treatment. The main therapeutic options include alkylating agents, nucleoside analogues, and rituximab. Studies involving combination chemotherapy are ongoing, and preliminary results are encouraging. No specific agent or regimen has been shown to be superior to another for treatment of WM. As such, novel therapeutic agents are needed for the treatment of WM. In ongoing efforts, we and others have sought to exploit advances made in the understanding of the biology of WM so as to better target therapeutics for this malignancy. These efforts have led to the development of several novel agents including the proteasome inhibitor bortezomib, and several Akt/mTor inhibitors, perifosine and Rad001, and immunomodulatory agents such as thalidomide and lenalidomide. Studies with monoclonal antibodies are ongoing and promising including the use of alemtuzumab, SGN-70, and the APRIL/BLYS blocking protein TACI-Ig atacicept. Other agents currently being tested in clinical trials include the PKC inhibitor enzastaurin, the natural product resveratrol, as well as the statin simvastatin. This report provides an update of the current preclinical studies and clinical efforts for the development of novel agents in the treatment of WM.

Waldenström macroglobulinemia

In the past 36 months, new developments have occurred both in the understanding of the biology of Waldenström macroglobulinemia (WM) and in therapeutic options for WM. Here, we review the classification, clinical features, and diagnostic criteria of the disease. WM is a B-cell neoplasm characterized by lymphoplasmacytic infiltration of the bone marrow and a monoclonal immunoglobulin M (IgM) protein. The symptoms of WM are attributable to the extent of tumor infiltration and to elevated IgM levels. The most common symptom is fatigue attributable to anemia. The prognostic factors predictive of survival include the patient's age, β2-microglobulin level, monoclonal protein level, hemoglobin concentration, and platelet count. Therapy is postponed for asymptomatic patients, and progressive anemia is the most common indication for initiation of treatment. The main therapeutic options include alkylating agents, nucleoside analogues, and rituximab. Studies involving combination chemotherapy are ongoing, and preliminary results are encouraging. No specific agent or regimen has been shown to be superior to another for treatment of WM. Novel agents such as bortezomib, perifosine, atacicept, oblimersen sodium, and tositumomab show promise as rational targeted therapy for WM.

Treatment of Waldenstrom’s Macroglobulinemia

Waldenstrom's macroglobulinemia is defined by bone marrow lymphoplasmacytic infiltration and by production of monoclonal IgM. Treatment is employed only to symptomatic patients. Alkylating agents (chlorambucil), nucleoside analogues and rituximab are reasonable choices for primary therapy. Combination therapy either with nucleoside analogues with alkylating agents and/or rituximab or rituximab with chemotherapy such as CHOP or cyclophosphamide are also reasonable frontline treatment options for WM patients. Several factors should be taken into account when choosing the most appropriate primary treatment. These factors include the age of the patient and possible co-morbidities, the presence of cytopenias and especially thrombocytopenia, the presence of symptoms and signs indicative of hyperviscosity, the need for rapid disease control due to severe symptoms, significant splenomegaly or lymphadenopathy, symptomatic peripheral neuropathy and whether the patient is candidate for autologous stem cell transplantation. For patients with refractory or relapsing disease, the use of an alternate first-line agent is reasonable. Outside the setting of a clinical trial, the administration of high-dose therapy should be reserved only for patients refractory to alkylating agents, purine nucleoside and rituximab. For patients who develop resistance to all three classes of agents, alemtuzumab, thalidomide with or without dexamethasone or bortezomib could be tried.

Waldenström's macroglobulinemia

The diagnosis of Waldenström's macroglobulinemia (WM) requires evidence of bone-marrow infiltration by lymphoplasmacytoid lymphoma and detection of serum monoclonal protein of IgM type. The normal counterpart of the WM malignant cell is believed to be a postgerminal-center B cell. The clinical manifestations and laboratory abnormalities associated with WM are related to direct tumor infiltration and to the amount and specific properties of IgM. Asymptomatic patients should be followed without treatment. When treatment is indicated, the three main choices for systemic frontline treatment are chlorambucil, the nucleoside analogues fludarabine or cladribine and the monoclonal antibody rituximab. There is evidence that high-dose therapy with autologous stem-cell transplantation is effective even in patients with advanced and resistant disease. Patient's age, hemoglobin and serum beta2-microglobulin before treatment are important prognostic variables which correlate with survival.

Myelodysplastic Syndrome with Complex Karyotypic Abnormality in a Patient with Waldenström's Macroglobulinemia after Sequential Treatment with Chlorambucil and Fludarabine

A therapy-related myelodysplastic syndrome (t-MDS) during the course of Waldenström's macroglobulinemia (WM) has been observed in rare patients. In most of them, the condition developed after treatment with alkylating agents. We experienced a 65-year-old male patient who was diagnosed as WM. He was treated with intermittent oral chlorambucil for 12 months and three cycles of fludarabine, and complete response was achieved after fludarabine treatment. During routine outpatient follow-up, severe anemia occurred. His bone marrow aspirate showed dysplastic hemopoiesis with ringed sideroblasts and siderocytes, which is consistent with MDS (refractory anemia with ringed sideroblasts). Cytogenetic analysis showed complex chromosomal abnormalities including 5q deletion, 12p deletion and monosomy 18. When decision is made to treat WM with chlorambucil and/or fludarabine, a potential risk for t-MDS or therapy-related acute myeloid leukemia should be considered and a close hematologic monitoring is needed.

Fludarabine Combination Therapy Is Highly Effective in First-Line and Salvage Treatment of Patients with Waldenström's Macroglobulinemia

Alkylating agents or single-agent purine analogues are modestly effective as front-line therapy for Waldenstrom's macroglobulinemia (WM), but response rates of < 50% are exhibited in the salvage therapy setting. Fludarabine combination therapy may be more effective, but no large studies exploring these regimens specifically in WM are available. We report our results of 18 cycles of fludarabine combination therapy: FC (fludarabine 25 mg/m2 for 3 days plus cyclophosphamide 250 mg/m2 for 3 days; n = 9), FM (fludarabine 25 mg/m2 for 3 days plus mitoxantrone 10 mg/m2 for 1 day; n = 3), FCR (FC plus rituximab 375 mg/m2; n = 5), or fludarabine/rituximab (n = 1). Four patients had previously untreated disease, and 14 had pretreated disease; 67% had elevated serum levels of beta2-microglobulin, and 86% had hemoglobin levels < or = 12 g/dL. Patients received a median of 4 cycles (range, 1-6 cycles), with grade > or = 3 neutropenia and infection complicating 25% and 4% of cycles, respectively. Objective responses (all partial) were attained in 13 patients (76%). Response rates did not significantly differ by regimen, previous treatment, age, performance status, beta2-microglobulin level, hemoglobin level, time from diagnosis, previous fludarabine exposure, or alkylator refractoriness. Median remission duration was 38 months; no previously untreated patient had died at a median of 37 months of follow-up, and the actuarial 5-year survival rate was 55% for pretreated patients. No cases of secondary myelodysplasia or leukemia were encountered.

Diagnosis and management of Waldenstrom's macroglobulinemia

PURPOSE

To review the diagnostic criteria, prognostic factors, response criteria, and treatment options of patients with Waldenstrom's macroglobulinemia (WM).

METHODS

A review of published reports was facilitated by the use of a MEDLINE computer search and by manual search of the Index Medicus.

RESULTS

WM should be regarded as a distinct clinicopathologic entity and confined to those patients with lymphoplasmacytoid lymphoma who have demonstrable serum immunoglobulin M monoclonal protein. Treatment decisions should rely on specific clinical and laboratory criteria. Initiation of therapy should not be based on serum monoclonal protein levels per se. The three main choices for systemic primary treatment of symptomatic patients with WM include alkylating agents (chlorambucil), nucleoside analogs (fludarabine and cladribine), and the monoclonal antibody rituximab. There are no data from prospective randomized studies to recommend the use of one first-line agent over another, although consideration of a patient's candidacy for autologous stem-cell transplantation (ASCT) should be taken into account to avoid stem cell-damaging agents. There are preliminary data to suggest that combinations of nucleoside analogs and alkylating agents with or without rituximab may improve response rates at the expense of higher toxicity.

CONCLUSION

WM is a distinct low-grade lymphoproliferative disorder. When therapy is indicated, alkylating agents, nucleoside analogs, and rituximab are reasonable choices. Several factors, including the presence of cytopenias, need for rapid disease control, candidacy for ASCT, age, and comorbidities, should be taken into consideration when choosing the most appropriate primary treatment.

Treatment of 72 newly diagnosed Waldenstrom macroglobulinemia cases with oral melphalan, cyclophosphamide, and prednisone: results and cost analysis

BACKGROUND

Current treatment regimens for Waldenstrom macroglobulinemia (WM) are based on the use of oral alkylating agents. Recently, however, other more costly agents have been proposed for the treatment of WM. In the current study, the authors report on results obtained using oral melphalan, cyclophosphamide, and prednisone (MCP) to treat 72 patients with WM, and they compare these results (and the associated costs) with those observed using more aggressive protocols.

METHODS

Between July 1973 and April 2002, the authors documented overexpression of the immunoglobulin M paraprotein in 317 consecutive patients. Of these, 100 had newly diagnosed WM, and the 72 who were symptomatic were treated using the MCP protocol. Response rate, overall survival (OS), response duration, freedom from progression (FFP), event-free survival (EFS) duration, toxicity, and cost per course in Euro and U.S. dollars were evaluated for patients receiving this regimen.

RESULTS

Seventy-one of 72 patients (99%) were evaluable. Of these patients, 55 (77%) achieved a response; 7 others (10%) experienced disease stabilization, and the remaining 9 (13%) experienced disease progression. After a median follow-up of 72 months (range, 3-195 months), the median durations of EFS, FFP, response, and OS were 47, 55, 64, and 66 months, respectively. No World Health Organization Grade III or IV toxicities were observed, and side effects were limited to transient nausea, emesis, and mild neutropenia. The cost per course of the MCP regimen was $16, similar to that of standard protocols involving chlorambucil and much less than that of more aggressive protocols (price range, $91-11091) proposed for the treatment of WM.

CONCLUSIONS

Like chlorambucil-based protocols, the MCP regimen is a cost-effective and safe option for the treatment of patients with WM. Furthermore, the results obtained do not appear to be inferior to those yielded by more expensive, aggressive, and toxic intravenous protocols.

Treatment for Waldenstrom’s macroglobulinemia

Waldenstrom's macroglobulinemia is a rare form of indolent lymphoma characterized by the production of a monoclonal immunoglobulin M protein, and complications such as hyperviscosity, cytopenias and peripheral neuropathy. Conventional treatment approaches are based on alkylators or nucleoside analogs, but in the absence of a clearly superior regimen, a broad array of alternative therapies exists. Choices range from biological agents to combination chemotherapy to stem-cell transplantation. A rational approach therefore must be based on careful patient assessment and individualization of therapy.

Fludarabine in Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM), a rare B-cell malignancy, is incurable. Conventional treatment consists of alkylating agents (especially chlorambucil), with or without corticosteroids. Purine analogues such as fludarabine are also active. Response rates to first-line therapy range from 38% to 85%. Discrepancies in response rates between different studies could be due to the small patient populations in two studies and to differences in patient characteristics and response criteria. Since 1990, several phase 2 trials of purine analogues have been done with previously treated patients; fludarabine induced responses in about one third of patients who were resistant to previous treatments. Response rates to fludarabine in previously treated patients range from 30% to 50% and are highest among patients who are still sensitive to their primary therapy. The responses last from 32 to 41 months. The principal toxicity of fludarabine is myelosuppression. Trials of fludarabine combination therapy with drugs such as rituximab are ongoing.

Waldenström's macroglobulinaemia: current therapy and future approaches

Waldenström's macroglobulinaemia is a rare B-cell malignancy. It is prevalent in the sixth and seventh decades, the median age at diagnosis being 63 years. Conventional treatment has involved alkylator therapy, especially chlorambucil given daily at a low dose or intermittently at a higher dose. Purine analogues, used initially as salvage therapy in refractory disease, are increasingly used for initial therapy. However, purine analogue therapy entails significant complications, including immunosuppression, pancytopenia and autoimmune haemolysis. Moreover, it is unclear whether purine analogues extend survival. All of these need to be considered before initiation of therapy. More recently, anti-CD20 monoclonal antibody and thalidomide have been used with a 30% response in treated patients. High-dose therapy with stem cell support achieves a partial response in a majority of patients receiving this modality of therapy. The median survival of 5 years has not improved considerably since the introduction of purine analogues. Complete response is still uncommon; using all available modalities of therapy may increase the complete response rate and improve survival. Great strides in understanding the malignant cell, the microenvironment and the potential interactions have identified potential targets for therapy in multiple myeloma. These agents may also be useful in Waldenström's macroglobulinaemia. Since this is a rare malignancy, all patients should be treated with well-designed clinical protocols to achieve improvement in outcome.

Waldenström's macroglobulinaemia

Waldenström's macroglobulinaemia (WM) is most usefully defined as a distinct chronic lymphoproliferative disorder with characteristic marrow morphology and phenotype; although nodal morphology if available will reveal a lymphoplasmacytoid lymphoma, the presence of a significant IgM paraprotein defines the clinical features of the disease. The clonal cell is a B-cell expressing IgM, CD19, and CD20 but not IgD, CD5, CD10 or CD23 and has somatic hypermutation of immunoglobulin heavy chain variable regions consistent with a post-germinal centre origin. Treatment of WM has been dependent on alkylating agents with or without coriticosteroids for many years, supplemented by the use of therapeutic plasmapheresis in the initial stages for patients at risk from the clinical consequences of hyperviscosity. This approach to treatment results in response rates of approximately 60% with a median survival of about 60 months. There is increasing evidence to show that the purine analogues fludarabine and cladribine which are active in the treatment of patients who are resistant to alkylating agents such as chlorambucil may be able to achieve higher response rates when used as initial therapy. A prospective trial is being undertaken to compare fludarabine and chlorambucil as initial treatment; because of the effect of subsequent active treatment on patients who do not respond to the first treatment choice, the long-term outcome may be similar for both groups. Recent advances in therapy include the use of therapeutic monoclonal antibodies such as rituximab and the use of autologous or allogeneic transplant procedures for selected patients.

Stem cell transplantation (SCT) for Waldenstrom's macroglobulinemia (WM)

Waldenstrom's macroglobulinemia (WM) is a low-grade lymphoplasmacytoid malignancy of unknown etiology. It primarily affects elderly patients and is characterized by a monoclonal IgM component, varying degrees of cytopenias, lymphadenopathy and manifestations related to hyperviscosity syndromes. WM is usually treated with single agent nucleoside analogues or alkylating agents that often provide high response rates and durable remissions. Recurrence of the disease after primary therapy is not uncommon, and resistance to both alkylating agents and nucleoside analogs eventually emerges. Small numbers of patients have undergone high-dose chemotherapy (HDC) with either autologous (n = 24) or allogeneic (n = 6) stem cell transplantation (SCT) as treatment for this disease. Most patients in both groups achieved remission. Results are promising and a more in-depth analysis of possible applications of this treatment modality is attempted with this mini-review.

Therapy-related refractory anemia with ringed sideroblasts in chronic lymphocytic leukemia. involvement of 3q21 region

Therapy-related myelodysplastic syndrome/acute myelogenous leukemia (t-MDS/AML) is extremely rare in chronic lymphocytic leukemia (CLL) despite extensive use of alkylating agents. We present a case of heavily treated CLL with resultant therapy-related refractory anemia with ringed sideroblasts (RARS). A complex cytogenetic abnormality including involvement of 3q21 was detected and to our knowledge, is the first report of a RARS case with a 3q21 abnormality.

Waldenström's macroglobulinemia: clinical features, complications, and management

PURPOSE

To review the clinical features, complications, and treatment of Waldenström's macroglobulinemia, a low-grade lymphoproliferative disorder that produces monoclonal immunoglobulin (Ig) M.

METHODS

A review of published reports was facilitated by the use of a MEDLINE computer search and by manual search of the Index Medicus.

RESULTS

The clinical manifestations associated with Waldenström's macroglobulinemia can be classified according to those related to direct tumor infiltration, to the amount and specific properties of circulating IgM, and to the deposition of IgM in various tissues. Asymptomatic patients should be followed without treatment. For symptomatic patients, standard treatment consists primarily of oral chlorambucil; nucleoside analogs, such as fludarabine and cladribine, are effective in one third of previously treated patients and in up to 80% of previously untreated patients. Preliminary evidence suggests that anti-CD20 monoclonal antibody may be active in about 30% of previously treated patients and that high-dose therapy with autologous stem-cell rescue is effective in most patients, including some with resistance to nucleoside analogs.

CONCLUSION

Waldenström's macroglobulinemia has a wide clinical spectrum that practicing physicians need to recognize early to reach the correct diagnosis. When therapy is indicated, oral chlorambucil is the standard primary treatment, but cladribine or fludarabine can be used when a rapid cytoreduction is desirable. Prospective randomized trials are required to elucidate the impact of nucleoside analogs on patients' survival. A nucleoside analog is the treatment of choice for patients who have been previously treated with an alkylating agent.