Choice of therapy for patients with Waldenstrom macroglobulinemia

Phase 3 Trial of Ibrutinib plus Rituximab in Waldenström's Macroglobulinemia

BACKGROUND

Single-agent ibrutinib has shown substantial activity in patients with relapsed Waldenström's macroglobulinemia, a rare form of B-cell lymphoma. We evaluated the effect of adding ibrutinib to rituximab in patients with this disease, both in those who had not received previous treatment and in those with disease recurrence.

METHODS

We randomly assigned 150 symptomatic patients to receive ibrutinib plus rituximab or placebo plus rituximab. The primary end point was progression-free survival, as assessed by an independent review committee. Key secondary end points were response rates, sustained hematologic improvement from baseline, and safety. The mutational status of MYD88 and CXCR4 was assessed in bone marrow samples.

RESULTS

At 30 months, the progression-free survival rate was 82% with ibrutinib-rituximab versus 28% with placebo-rituximab (hazard ratio for progression or death, 0.20; P<0.001). The benefit in the ibrutinib-rituximab group over that in the placebo-rituximab group was independent of the MYD88 or CXCR4 genotype. The rate of major response was higher with ibrutinib-rituximab than with placebo-rituximab (72% vs. 32%, P<0.001). More patients had sustained increases in hemoglobin level with ibrutinib-rituximab than with placebo-rituximab (73% vs. 41%, P<0.001). The most common adverse events of any grade with ibrutinib-rituximab included infusion-related reactions, diarrhea, arthralgia, and nausea. Events of grade 3 or higher that occurred more frequently with ibrutinib-rituximab than with placebo-rituximab included atrial fibrillation (12% vs. 1%) and hypertension (13% vs. 4%); those that occurred less frequently included infusion reactions (1% vs. 16%) and any grade of IgM flare (8% vs. 47%). The major hemorrhage rate was the same in the two trial groups (4%).

CONCLUSIONS

Among patients with Waldenström's macroglobulinemia, the use of ibrutinib-rituximab resulted in significantly higher rates of progression-free survival than the use of placebo-rituximab, both among those who had received no previous treatment and among those with disease recurrence. Atrial fibrillation and hypertension were more common with ibrutinib-rituximab, whereas infusion reactions and IgM flare were more common with placebo-rituximab. (Funded by Pharmacyclics and Janssen Research and Development; ClinicalTrials.gov number, NCT02165397 .).

Evolution of Management and Outcomes in Waldenström Macroglobulinemia: A Population-Based Analysis

INTRODUCTION

Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (WM) is a rare lymphoma affecting older patients. Its management largely relies on small phase II trials and it is unclear how their results translate into clinical practice in the community.

METHOD

We evaluated changes in the presentation, management, and survival among 2,666 Medicare beneficiaries diagnosed with WM between 1994 and 2011, using Medicare claims linked to Surveillance, Epidemiology and End Results data.

RESULTS

Prevalence of transfusions, anemia, thrombocytopenia, and neuropathy at diagnosis significantly increased over time, whereas the use of plasmapheresis was low (2.5%) and stable. The proportion of patients starting chemotherapy within 1 year of WM diagnosis increased from 39% in 1994 to 62% in 2011 (p < .0001). Treatments based on classic alkylators and purine analogs predominated in the 1990s, but were quickly replaced by rituximab-containing regimens after 2000. Rituximab monotherapy has been prescribed for >50% of patients since 2004, and combination chemoimmunotherapy for a further 30%. Most patients initiating multiagent regimens in 2012-2013 received rituximab with bortezomib or bendamustine. These changes were accompanied by significant improvements in overall and WM-related survival, but also by a significant increase in cost of chemotherapy. Mean Medicare payments for chemotherapy drugs accrued in the first year of treatment rose from $9,464 in 1994-2000 to $29,490 after 2008.

CONCLUSION

Hematologists have rapidly adopted innovative, expensive therapies for WM before completion of randomized trials. This underscores the need to assess the comparative value of such therapies in rare malignancies through a combination of clinical and observational data.

IMPLICATIONS FOR PRACTICE

Most older patients with Waldenström macroglobulinemia currently treated in the U.S. receive rituximab as monotherapy or in combination with bortezomib or bendamustine. Newly designed trials should consider control arms aligned with this prevalent real-life standard. Compared with the 1990s, patients diagnosed according to current criteria are more likely to have anemia or neuropathy, or to receive early chemotherapy, but only 2.5% require plasmapheresis at diagnosis. The incremental clinical value of newly introduced agents needs to be assessed through a combination of clinical and health services research, taking into consideration their associated survival benefits, toxicities, and associated costs of care.

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.

Waldenström macroglobulinemia: What a hematologist needs to know

Waldenström macroglobulinemia (WM) is a distinct hematologic malignancy characterized by a lymphoplasmacytic bone marrow infiltration and the presence of immunoglobulin (Ig)M monoclonal protein. Patients typically present at an advanced age, and a substantial proportion are asymptomatic at diagnosis. A unifying diagnosis of WM may be missed by an unsuspecting hematologist, as symptomatic patients present with a multitude of non-specific manifestations. Although constitutional and neuropathy-related symptoms predominate, concomitant IgM-induced hyperviscosity-associated features can provide useful diagnostic clues. There are specific indications for initiation of therapy. This review focuses on the most up-to-date management strategies of WM, in addition to highlighting the recent discoveries of MYD88 and CXCR4 mutations that have shed unprecedented light on the complex signaling pathways, and opened avenues for novel therapeutic targeting. Although WM remains incurable, with the rapid emergence and integration of effective novel therapies, its clinical course appears poised to improve in the foreseeable future.

Waldenström macroglobulinemia in hepatitis C: case report and review of the current literature

Background. Recent literature has associated hepatitis C virus with the development of non-Hodgkin lymphoma. Hepatitis C virus infection appears to promote lymphoproliferation, providing a plausible mechanism for a causative association; however, despite prior reports of patients with comorbid hepatitis C infection and Waldenström macroglobulinemia, the literature is in disagreement regarding whether there exists an association between these two conditions. Case Presentation. This case report describes a 57-year-old African-American male with chronic hepatitis C infection and cryoglobulinemia who presented with several episodes of transient confusion and paralysis and was found to have symptomatic hyperviscosity. The recognition of his condition was facilitated by characteristic findings on ophthalmologic examination. He was subsequently diagnosed with Waldenström macroglobulinemia on bone marrow biopsy. Conclusions. An up to date, comprehensive review of the literature suggests an association between hepatitis C and Waldenström macroglobulinemia. Data on optimal treatment of patients with comorbid hepatitis C infection and Waldenström macroglobulinemia is limited. We have provided a comprehensive review of previously explored treatment options to guide management of other similar patients. Our patient has since been treated with repeated plasmapheresis with a plan to pursue antiviral therapy.

Waldenström macroglobulinemia: clinical and immunological aspects, natural history, cell of origin, and emerging mouse models

Waldenström macroglobulinemia (WM) is a rare and currently incurable neoplasm of IgM-expressing B-lymphocytes that is characterized by the occurrence of a monoclonal IgM (mIgM) paraprotein in blood serum and the infiltration of the hematopoietic bone marrow with malignant lymphoplasmacytic cells. The symptoms of patients with WM can be attributed to the extent and tissue sites of tumor cell infiltration and the magnitude and immunological specificity of the paraprotein. WM presents fascinating clues on neoplastic B-cell development, including the recent discovery of a specific gain-of-function mutation in the MYD88 adapter protein. This not only provides an intriguing link to new findings that natural effector IgM⁺IgD⁺ memory B-cells are dependent on MYD88 signaling, but also supports the hypothesis that WM derives from primitive, innate-like B-cells, such as marginal zone and B1 B-cells. Following a brief review of the clinical aspects and natural history of WM, this review discusses the thorny issue of WM's cell of origin in greater depth. Also included are emerging, genetically engineered mouse models of human WM that may enhance our understanding of the biologic and genetic underpinnings of the disease and facilitate the design and testing of new approaches to treat and prevent WM more effectively.