Treatment Strategies in Elderly Patients with Multiple Myeloma

Multiple myeloma (MM), a plasma cell malignancy, is a disorder of the elderly with an increasing prevalence as the average life expectancy increases. Survival remains unacceptably low in elderly patients with MM, in whom the gold standard of treatment has been, until recently, oral melphalan and prednisolone, which induces a response rate of approximately 50% and overall survival of <3 years. In the last 15 years, traditional treatment paradigms for elderly patients with MM have been challenged not only as a result of the change in what we define as 'elderly' but also as a result of the reduced morbidity and treatment-related mortality associated with high-dose chemoradiotherapy (HDT) and autologous stem cell transplantation (ASCT), and the emergence of novel therapies including thalidomide, its immunomodulator drug derivative lenalidomide and the first-in-class proteasome inhibitor, bortezomib. In this review, we examine currently available data regarding the treatment of MM in the elderly population. Recent years have seen a paradigm shift in the standard of care of elderly patients with MM from oral melphalan and prednisolone to approaches including HDT with ASCT using intermediate-dose melphalan in selected elderly patients, and the evaluation of and incorporation of drugs such as thalidomide, bortezomib and lenalidomide. Importantly, we now have been able to change the traditional goal of palliation in the elderly group of patients to a more ambitious objective of achieving a complete response or a near complete response, in the hope that this will translate into improved progression-free survival, overall survival and quality of life.

Bortezomib, melphalan, prednisone, and thalidomide for relapsed multiple myeloma

In multiple myeloma (MM), the addition of thalidomide or bortezomib to the standard oral melphalan/prednisone combination significantly increased response rate and event-free survival. In this multicenter phase 1/2 trial, dosing, safety, and efficacy of the 4-drug combination, bortezomib, melphalan, prednisone, and thalidomide (VMPT) was determined. Bortezomib was administered at 3 dose levels (1.0 mg/m2, 1.3 mg/m2, or 1.6 mg/m2) on days 1, 4, 15, and 22; melphalan was given at a dose of 6 mg/m2 on days 1 through 5 and prednisone at 60 mg/m2 on days 1 through 5. Thalidomide was delivered at 50 mg on days 1 through 35. Each course was repeated every 35 days. The maximum tolerated dose of bortezomib was 1.3 mg/m2. Thirty patients with relapsed or refractory MM were enrolled; 20 patients (67%) achieved a partial response (PR) including 13 patients (43%) who achieved at least a very good PR. Among 14 patients who received VMPT as second-line treatment, the PR rate was 79% and the immunofixation-negative complete response rate 36%. The 1-year progression-free survival was 61%, and the 1-year survival from study entry was 84%. Grade 3 nonhematologic adverse events included infections (5 patients), fatigue (1), vasculitis (1), and peripheral neuropathy (2); no grade 4 toxicities were recorded. Initial results showed that VMPT is an effective salvage therapy with a very high proportion of responses. The incidence of neurotoxicities was unexpectedly low.

A Multicenter Retrospective Analysis of Adverse Events in Korean Patients Using Bortezomib for Multiple Myeloma

The proteasome inhibitor bortezomib has demonstrated clinical activity in patients with multiple myeloma (MM). Adverse events, including thrombocytopenia and peripheral neuropathy, have affected 30% to 60% of patients overall, and interrupted therapy in 10% to 20%. No prior toxicity data are available for Asian patients who have used bortezomib for MM. We used National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, to review the clinical records of patients with an MM diagnosis from 25 centers in Korea. The included patients were treated with bortezomib alone or in combination with other agents, including thalidomide. Ninety-five MM patients were treated. The patients had a median age of 60 years (range, 42-77 years). The median number of previous treatments was 3 (range, 0-10), and 39% of the patients had been treated with 4 or more major classes of agents, including thalidomide (67%), and autologous stem cell transplantation (51%). Regimens included bortezomib only in 38 patients (40%), bortezomib plus dexamethasone in 34 patients (36%), and bortezomib plus a thalidomide-containing regimen in 23 patients (24%). The analysis of patient response to therapy revealed a complete response (CR) or a near-CR in 31 patients (33%) and a partial response in 30 patients (32%), for an objective response rate of 65% in 93 patients. The most common adverse events reported were thrombocytopenia (47%), sensory neuropathy (42%), anemia (31%), and leukopenia (31%). Thirteen patients (14%) stopped therapy because of adverse events (neuropathy, 8; infection, 4; diarrhea, 1). Neuropathy greater than grade 2 was more frequent in patients who received 4 or more prior therapy regimens (17/37) than in those who received 3 or fewer (14/58). In addition, therapy including thalidomide was significantly correlated with neuropathy of grades 1 to 3 (P = .001). We identified 6 therapy-related deaths (6%) within 20 days after the last dose of bortezomib. The causes of death were infection in 3 patients, disease progression in 2 patients, and suicide in 1 patient. The incidences of thrombocytopenia and neurotoxicity were similar; however, gastrointestinal toxicities were relatively low in Korean patients compared with those reported in Western studies. Significant neuropathy was associated with the number of prior regimens and combination with thalidomide. These findings provide useful information for clinicians and patients using bortezomib.

Results of a phase I/II trial adding carmustine (300 mg/m2) to melphalan (200 mg/m2) in multiple myeloma patients undergoing autologous stem cell transplantation

Autologous stem cell transplantation (SCT) with high-dose melphalan (HDM, 200 mg/m2) is the most effective therapy for multiple myeloma. To determine the feasibility of combining carmustine (300 mg/m2) with HDM, we enrolled 49 patients with previously treated Durie-Salmon stage II/III myeloma (32M/17W, median age 53) on a phase I/II trial involving escalating doses of melphalan (160, 180, 200 mg/m2). The median beta2-microglobulin was 2.5 (0-9.3); marrow karyotypes were normal in 88%. The phase I dose-limiting toxicity was > or =grade 2 pulmonary toxicity 2 months post-SCT. Other endpoints were response rate and progression-free survival (PFS). HDM was safely escalated to 200 mg/m2; treatment-related mortality was 2% and > or =grade 2 pulmonary toxicity 10%. The complete (CR) and near complete (nCR) response rate was 49%. With a median post-SCT follow-up of 2.9 years, the PFS and overall survival (OS) post-SCT were 2.3 and 4.7 years. PFS for those with CR or nCR was 3.1 years while for those with stable disease (SD) it was 1.3 years (P=0.06). We conclude that carmustine can be combined with HDM for myeloma with minimal pulmonary toxicity and a high response rate.

New Approaches to Treatment for Multiple Myeloma: Durable Remission and Quality of Life as Primary Goals

New treatment approaches are changing the traditional paradigm for myeloma management. Partial or complete response with first-line therapy is now highly attainable. The focus of attention has thus shifted to obtaining the most durable remissions with the highest quality of life. A critical open question is whether more arduous and toxic therapies are justified with the intent to seek a cure. Patients with minimal symptoms at diagnosis are particularly reluctant to pursue aggressive strategies without documented long-term benefit. Conversely, patients with poor-risk molecular features, such as 13q deletion or t(4;14) translocation, can hopefully benefit from novel targeted therapies. New combinations incorporating bortezomib, thalidomide, and/or lenalidomide plus other novel agents offer the opportunity to explore therapy that is more effective and less toxic than in the past. The efficacy of single and tandem transplantation, which have documented long-term survival benefit, need to be compared with regimens integrating novel therapies. Whether true complete remission is a prerequisite for substantially improved survival is a central question in the framework of planned trials. The ultimate goal is to achieve clinical response (complete or partial) that offers the best quality remission for the longest period. Ideally, more effective induction and/or consolidation treatments will avoid concomitant toxicities and the need for maintenance therapies. Fortunately, new agents already offer longer-term disease control. The ongoing search for a cure will undoubtedly demand courage and dedication on the part of investigators and patients.

An Update of the Management of Multiple Myeloma: The Changing Landscape

The management of multiple myeloma is rapidly changing. Cytogenetic, molecular and proteomic techniques have led to a better understanding of the pathophysiology of this heterogeneous malignancy. Novel agents designed to interrupt myeloma growth and survival pathways have entered into clinical usage with unprecedented speed, while new prognostic systems based on clinical and biologic features, such as cytogenetic abnormalities, have been developed. A plethora of clinical trials have been initiated utilizing novel agents, alone or in conjunction with established modalities such as conventional cytotoxic agents and stem cell transplantation. These newer treatments have increased the antitumor response rates in this disease and have provided options for patients whose disease has become resistant to conventional therapy. A major challenge is to define the optimal use of these new agents and combinations in order to significantly impact the natural history of myeloma.