Renal, GI, and Peripheral Nerves: Evidence-Based Recommendations for the Management of Symptoms and Care for Patients With Multiple Myeloma

BACKGROUND: A majority of patients with multiple myeloma experience damage to the kidneys and peripheral nerves either at diagnosis or throughout the disease. Symptoms of diarrhea, nausea, vomiting, or constipation can also occur. Prevention and management of disease- and treatment-related side effects are essential to treatment adherence.
. OBJECTIVES: This article aims to provide insight into prevention and management of organ health-related toxicities and give best practice recommendations for optimal nursing care.
. METHODS: The authors performed a literature search, and articles were reviewed for relevance to each organ-related topic. FINDINGS: Prevention and management strategies include close monitoring and prompt intervention when organ damage develops to reverse impairment and maintain adherence to therapy when indicated.

Lack of health maintenance examinations and risk in myeloma patients.

Health maintenance (HM) practices are essential to prevent illness, promote well-being, and maximize health. Patients with multiple myeloma (MM) are at increased risk for cardiovascular disease and cancers, yet, research on HM practices and preventative care of MM survivors has limited report. The study comprised a descriptive, correlational, and cross-sectional online survey design. Survey of patients with MM was carried out through the International Myeloma Foundation (IMF) and the Association of Cancer Online Resources (ACOR) e-mail list services. The members of the IMF and ACOR e-mail list services were surveyed, of which 237 patients responded. The modified Medical Expenditure Preventive Survey-Preventive Care questionnaire was used; it included items that ask patients regarding their healthcare practices that relate to dental care, cancer prevention, addiction, lifestyles, sensory screening, immunizations, cardiovascular, endocrine, psychosocial, and bone health. Descriptive statistics, Pearson's chi-square, and Spearman's rho correlation coefficient were obtained. In this study, men had statistically significant inferior global health maintenance scores than women (P = 0.002). Being employed (P = 0.054) and married or partnered (P = 0.017) were significantly correlated with better health maintenance patterns among male respondents. In contrast, no statistically significant correlations between sociodemographic factors and health maintenance patterns were found in women. Patients with MM, particularly men, require continued education and close monitoring of health maintenance practices. These findings are consistent with publications looking at gender disparities in healthcare utilization in the United States. Studies show that men, in general, are less likely to seek preventative healthcare screenings. Healthcare providers must incorporate health maintenance promotion during clinic visits.

Phase 1 study of pomalidomide MTD, safety, and efficacy in patients with refractory multiple myeloma who have received lenalidomide and bortezomib.

This phase 1 dose-escalation study determined the maximum tolerated dose (MTD) of oral pomalidomide (4 dose levels) administered on days 1 to 21 of each 28-day cycle in patients with relapsed and refractory multiple myeloma (RRMM). After four cycles, patients who progressed or had not achieved minimal response (serum and urine M-protein reduction of ≥ 25% and ≥ 50%) could receive dexamethasone 40 mg per week. Safety and efficacy were evaluated. Thirty-eight patients who had received both bortezomib and lenalidomide (median 6 prior therapies) were enrolled; 63% were refractory to both lenalidomide and bortezomib. There were four dose-limiting toxicities (grade 4 neutropenia) at 5 mg per day and so the MTD was 4 mg per day. Rates of peripheral neuropathy and venous thromboembolism were low (≤ 5%). Among the 38 patients enrolled (including 22 with added dexamethasone), 42% achieved minimal response or better, 21% achieved partial response or better, and 3% achieved complete response. Median duration of response, progression-free survival, and overall survival were 4.6, 4.6, and 18.3 months, respectively. Pomalidomide 4 mg per day on days 1 to 21 of each 28-day cycle, with or without dexamethasone (40 mg/week), has encouraging activity with manageable toxicity in RRMM, including those refractory to both lenalidomide and bortezomib. This study is registered at http://www.clinicaltrials.gov as #NCT00833833.

The potential benefits of participating in early-phase clinical trials in multiple myeloma: long-term remission in a patient with relapsed multiple myeloma treated with 90 cycles of lenalidomide and bortezomib.

We present the case of a woman with relapsed multiple myeloma (MM) who received combination lenalidomide and bortezomib therapy for 90 cycles followed by continuous lenalidomide monotherapy and has completed over 100 cycles of treatment to date. The patient was diagnosed with advanced-stage, symptomatic MM in 2001. Following a partial response (PR) to dexamethasone in combination with pamidronate and thalidomide, the patient underwent protocol-directed non-myeloablative allogeneic bone marrow transplantation from her matched sibling donor the following year. In 2004, the patient relapsed and was enrolled in a phase I, dose-escalation trial of lenalidomide plus bortezomib for relapsed and refractory MM. After eight cycles of study treatment, the patient achieved a minimal response. The patient received a total of 90 cycles of treatment with lenalidomide 5 mg given for 14 d every 21 d, and 1 mg/m(2) of bortezomib initially given on days 1, 4, 8, and 11 for the first 20 cycles, and then weekly thereafter on days 1 and 8. Bortezomib was discontinued after 90 cycles, and the patient continued to receive lenalidomide monotherapy. As of cycle 100, the patient achieved a PR. Currently, she is clinically stable with response sustained for over 7 yrs. Therapy has been well tolerated with no significant long-term toxicity; no dose reductions of lenalidomide and bortezomib were required. The excellent tolerability of this steroid-free approach and the durable response seen underscore the potential benefits of participating in early-phase clinical trials evaluating novel therapies and new drug combinations. This case further supports that combination treatment with lenalidomide and bortezomib is an effective therapy in the management of patients with relapsed and refractory MM.

Sexual dysfunction in multiple myeloma: survivorship care plan of the International Myeloma Foundation Nurse Leadership Board.

The World Health Organization describes sexuality as a "central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is influenced by the interaction of biological, psychological, social, economic, political, cultural, ethical, legal, historical, religious, and spiritual factors." Currently, no research has been conducted regarding sexual dysfunction in patients with multiple myeloma; therefore, information related to the assessment and evaluation of sexual dysfunction is gleaned from other malignancies and diseases. In this article, members of the International Myeloma Foundation's Nurse Leadership Board discuss the definition, presentation, and causes of sexual dysfunction; provide recommendations for sexual assessment practices; and promote discussion among patients with multiple myeloma, their healthcare providers, and their partners.

Tailoring treatment for multiple myeloma patients with relapsed and refractory disease.

Responses to treatment of relapsed and refractory multiple myeloma are characteristically short, and median survival is as brief as 6 months. Although prognostic factors in the context of relapsed and refractory disease require further characterization, high-risk patients include those with certain cytogenetic abnormalities, high beta2-microglobulin, and low serum albumin. The development of novel therapies targeting disease biology and tumor microenvironment has significantly improved the outlook for patients with relapsed and refractory disease, with bortezomib (Velcade), a first-in-class proteasome inhibitor, and the immunomodulatory agents thalidomide (Thalomid) and lenalidomide (Revlimid) constituting "backbone"agents in this setting. More recent approaches for treating relapsed and refractory myeloma that are recommended by the National Comprehensive Cancer Network include single-agent bortezomib, single-agent lenalidomide, bortezomib/dexamethasone, bortezomib plus pegylated liposomal doxorubicin, lenalidomide/dexamethasone, and lenalidomide/bortezomib/dexamethasone. Individualized treatment of progressive myeloma should take into account the time to progression and/or the type of prior therapy. Additional clinical challenges discussed in this article are renal dysfunction, extramedullary disease, and advanced bone disease. Finally, participation in clinical trials is especially encouraged in this patient population.

Lenalidomide, bortezomib, and dexamethasone combination therapy in patients with newly diagnosed multiple myeloma.

This phase 1/2 study is the first prospective evaluation of lenalidomide-bortezomib-dexamethasone in front-line myeloma. Patients (N = 66) received 3-week cycles (n = 8) of bortezomib 1.0 or 1.3 mg/m(2) (days 1, 4, 8, 11), lenalidomide 15 to 25 mg (days 1-14), and dexamethasone 40 or 20 mg (days 1, 2, 4, 5, 8, 9, 11, 12). Responding patients proceeded to maintenance or transplantation. Phase 2 dosing was determined to be bortezomib 1.3 mg/m(2), lenalidomide 25 mg, and dexamethasone 20 mg. Most common toxicities included sensory neuropathy (80%) and fatigue (64%), with only 27%/2% and 32%/3% grade 2/3, respectively. In addition, 32% reported neuropathic pain (11%/3%, grade 2/3). Grade 3/4 hematologic toxicities included lymphopenia (14%), neutropenia (9%), and thrombocytopenia (6%). Thrombosis was rare (6% overall), and no treatment-related mortality was observed. Rate of partial response was 100% in both the phase 2 population and overall, with 74% and 67% each achieving very good partial response or better. Twenty-eight patients (42%) proceeded to undergo transplantation. With median follow-up of 21 months, estimated 18-month progression-free and overall survival for the combination treatment with/without transplantation were 75% and 97%, respectively. Lenalidomide-bortezomib-dexamethasone demonstrates favorable tolerability and is highly effective in the treatment of newly diagnosed myeloma. This study is registered at http://clinicaltrials.gov as NCT00378105.

Multicenter, phase I, dose-escalation trial of lenalidomide plus bortezomib for relapsed and relapsed/refractory multiple myeloma.

PURPOSE: Lenalidomide and bortezomib are active in relapsed and relapsed/refractory multiple myeloma (MM). In preclinical studies, lenalidomide sensitized MM cells to bortezomib and dexamethasone. This phase I, dose-escalation study (ie, NCT00153933) evaluated safety and determined the maximum-tolerated dose (MTD) of lenalidomide plus bortezomib in patients with relapsed or with relapsed and refractory MM. PATIENTS AND METHODS: Patients received lenalidomide 5, 10, or 15 mg/d on days 1 through 14 and received bortezomib 1.0 or 1.3 mg/m(2) on days 1, 4, 8, and 11 of 21-day cycles. Dexamethasone (20mg or 40 mg on days 1, 2, 4, 5, 8, 9, 11, and 12) was added for progressive disease after two cycles. Primary end points were safety and MTD determination. RESULTS: Thirty-eight patients were enrolled across six dose cohorts. The MTD was lenalidomide 15 mg/d plus bortezomib 1.0 mg/m(2). Dose-limiting toxicities (n = 1 for each) were grade 3 hyponatremia and herpes zoster reactivation and grade 4 neutropenia. The most common treatment-related, grades 3 to 4 toxicities included reversible neutropenia, thrombocytopenia, anemia, and leukopenia. Among 36 response-evaluable patients, 61% (90% CI, 46% to 75%) achieved minimal response or better. Among 18 patients who had dexamethasone added, 83% (90% CI, 62% to 95%) achieved stable disease or better. Median overall survival was 37 months. CONCLUSION: Lenalidomide plus bortezomib was well tolerated and showed promising activity with durable responses in patients with relapsed and relapsed/refractory MM, including patients previously treated with lenalidomide, bortezomib, and/or thalidomide. The combination of lenalidomide, bortezomib, and dexamethasone is being investigated in a phase II study in this setting and in newly diagnosed MM.

Single-agent bortezomib in previously untreated multiple myeloma: efficacy, characterization of peripheral neuropathy, and molecular correlations with response and neuropathy.

PURPOSE To assess efficacy and safety of single-agent bortezomib in previously untreated patients with multiple myeloma, investigate prevalence of baseline and treatment-emergent polyneuropathy, and identify molecular markers associated with response and neuropathy. PATIENTS AND METHODS Patients received bortezomib 1.3 mg/m(2) on days 1, 4, 8, and 11, for up to eight 21-day cycles. A subset of patients underwent neurophysiologic evaluation pre- and post-treatment. Bone marrow aspirates were performed at baseline for exploratory whole-genome analyses. Results Among 64 patients, 41% had partial response or better, including 9% complete/near-complete responses; median duration of response was 8.4 months. Response rates did not differ in the presence or absence of adverse cytogenetics. After median follow-up of 29 months, median time to progression was 17.3 months. Median overall survival had not been reached; estimated 1-year survival was 92%. Thirty-two patients successfully underwent optional stem-cell transplantation. Bortezomib treatment was generally well tolerated. At baseline, 20% of patients had sensory polyneuropathy. Sensory polyneuropathy developed during treatment in 64% of patients (grade 3 in 3%), but proved manageable and resolved in 85% within a median of 98 days. Neurologic examination, neurophysiologic testing, and measurements of epidermal nerve fiber densities in 35 patients confirmed pretreatment sensory neuropathy in 20% and new or worsening neuropathy in 63%. Pharmacogenomic analyses identified molecular markers of response and treatment-emergent neuropathy, which will require future study. CONCLUSION Single-agent bortezomib is effective in previously untreated myeloma. Baseline myeloma-associated neuropathy seems more common than previously reported, and bortezomib-associated neuropathy, although a common toxicity, is reversible in most patients.

Management of side effects of novel therapies for multiple myeloma: consensus statements developed by the International Myeloma Foundation's Nurse Leadership Board.

Nurses play an essential role in managing the care of patients with multiple myeloma, who require education and support to receive and adhere to optimal therapy. The International Myeloma Foundation created a Nurse Leadership Board comprised of oncology nurses from leading cancer centers and community practices. An assessment survey identified the need for specific recommendations for managing key side effects of novel antimyeloma agents. Myelosuppression, thromboembolic events, peripheral neuropathy, steroid toxicities, and gastrointestinal side effects were selected for the first consensus statements. The board developed recommendations for healthcare providers in any medical setting, including grading of side-effect toxicity and strategies for managing the side effects in general, with specific recommendations pertaining to the novel agents.

Thromboembolic events associated with novel therapies in patients with multiple myeloma: consensus statement of the IMF Nurse Leadership Board.

Patients with myeloma are at risk for serious and life-threatening thromboembolic events because of their disease, individual risk factors, and antimyeloma or other medications. The International Myeloma Foundation's Nurse Leadership Board developed this consensus statement for assessment and prevention of thromboembolic events. Prophylactic measures are categorized as mechanical, regimen related, and antithrombotic drug, based on individual and myeloma-related risk factors. Aspirin is suggested for patients with no or one risk factor, low-molecular-weight heparin or full-dose warfarin for patients with two or more risk factors, and low-molecular-weight heparin or full-dose warfarin for all patients with therapy-related risks, including high-dose dexamethasone, doxorubicin, or multiagent chemotherapy.

Expanding role of bortezomib in multiple myeloma: nursing implications.

Multiple myeloma is the second most common hematologic malignancy and remains incurable, despite advances in chemotherapy and stem cell transplantation. Bortezomib, a novel proteasome inhibitor, is approved for the treatment of patients with multiple myeloma who have received at least 1 prior therapy. In the assessment of proteasome inhibition for extending remissions phase III trial of bortezomib versus high-dose dexamethasone, bortezomib led to significantly longer survival and time to progression and higher response rate in patients with relapsed multiple myeloma. The principal adverse events were gastrointestinal effects, fatigue, transient thrombocytopenia, and reversible peripheral neuropathy. The side effect profile of bortezomib is extensively characterized, predictable, and generally manageable; retreatment or extended bortezomib therapy seems well tolerated. Nurses play a unique role in bortezomib treatment: they are often closest to the patients and are most able to educate patients about side effects and, if necessary, take appropriate action, independently or collaboratively with healthcare team members. In this review, we present the latest efficacy and safety data for bortezomib in relapsed multiple myeloma and characterize common side effects associated with bortezomib and the implications for nursing. We also highlight practical strategies for preventing and managing side effects, thereby enhancing the clinical benefit of bortezomib-based therapies to patients.

Advances in oral therapy in the treatment of multiple myeloma.

Conventional IV chemotherapy regimens used for induction chemotherapy or salvage therapy in the treatment of multiple myeloma (MM) are cumbersome, with a negative impact on patient quality of life. A number of new oral drugs, including immunomodulatory agents such as thalidomide and lenalidomide, have demonstrated potent antimyeloma activity in relapsed and refractory as well as newly diagnosed MM. Clinically, response rates of 56%-72% have been reported with the combination of thalidomide and dexamethasone in patients with newly diagnosed disease; however, the combination is associated with a higher incidence of side effects, including constipation, somnolence, peripheral neuropathy, and thromboembolic complications. In contrast, preliminary safety and efficacy data from clinical studies of lenalidomide show promise. Response rates as high as 83% have been reported in patients with newly diagnosed MM, and the most common adverse event is manageable myelosuppression, which is reversible with dose reduction. Lenalidomide has different toxicities than thalidomide, exhibiting greater myelosuppression but virtually no constipation, somnolence, or peripheral neuropathy. Oncology nurses play a key role in monitoring patients for side effects and pain control and educating them about emerging treatment options. This article reviews the nursing experience with oral agents in the treatment of MM.

A randomized phase 2 study of lenalidomide therapy for patients with relapsed or relapsed and refractory multiple myeloma.

This multicenter, open-label, randomized phase 2 study evaluated 2 dose regimens of lenalidomide for relapsed, refractory myeloma. Seventy patients were randomized to receive either 30 mg once-daily or 15 mg twice-daily oral lenalidomide for 21 days of every 28-day cycle. Patients with progressive or stable disease after 2 cycles received dexamethasone. Analysis of the first 70 patients showed increased grade 3/4 myelo-suppression in patients receiving 15 mg twice daily (41% versus 13%, P = .03). An additional 32 patients received 30 mg once daily. Responses were evaluated according to European Group for Blood and Marrow Transplantation (EBMT) criteria. Overall response rate (complete, partial, or minor) to lenalidomide alone was 25% (24% for once-daily and 29% for twice-daily lenalidomide). Median overall survival in 30-mg once-daily and twice-daily groups was 28 and 27 months, respectively. Median progression-free survival was 7.7 months on once-daily versus 3.9 months on twice-daily lenalidomide (P = .2). Dexamethasone was added in 68 patients and 29% responded. Time to first occurrence of clinically significant grade 3/4 myelosuppression was shorter in the twice-daily group (1.8 vs 5.5 months, P = .05). Significant peripheral neuropathy and deep vein thrombosis each occurred in only 3%. Lenalidomide is active and well tolerated in relapsed, refractory myeloma, with the 30-mg once-daily regimen providing the basis for future studies as monotherapy and with dexamethasone.

Aspirin, ibuprofen, and other non-steroidal anti-inflammatory drugs in cancer prevention: a critical review of non-selective COX-2 blockade (review).

We comprehensively reviewed the published scientific literature on non-steroidal anti-inflammatory drugs (NSAIDs) and cancer and evaluated results based upon epidemiologic criteria of judgment: consistency of results, strength of association, dose response, molecular specificity, and biological plausibility. Sufficient data from 91 epidemiologic studies were available to examine the dose response of relative risk and level of NSAID intake for ten human malignancies. Dose response curves were fitted by exponential regression. Results showed a significant exponential decline in the risk with increasing intake of NSAIDs (primarily aspirin or ibuprofen) for 7-10 malignancies including the four major types: colon, breast, lung, and prostate cancer. Daily intake of NSAIDs, primarily aspirin, produced risk reductions of 63% for colon, 39% for breast, 36% for lung, and 39% for prostate cancer. Significant risk reductions were also observed for esophageal (73%), stomach (62%), and ovarian cancer (47%). NSAID effects became apparent after five or more years of use and were stronger with longer duration. Observed protective effects were also consistently stronger for gastrointestinal malignancies (esophagus, stomach, and colon). Results for pancreatic, urinary bladder, and renal cancer were inconsistent. Initial epidemiologic studies of malignant melanoma, Hodgkin's disease, and adult leukemia also found that NSAIDs are protective. A few studies suggest that ibuprofen has stronger anticancer effects than aspirin, particularly against breast and lung cancer. Overexpression of cyclooxygenase-2 (COX-2) and increased prostaglandin biosynthesis correlates with carcinogenesis and metastasis at most anatomic sites. Preclinical investigations provide consistent evidence that both selective and non-selective NSAIDs effectively inhibit chemically-induced carcinogenesis of epithelial tumors. This review provides compelling and converging evidence that regular intake of NSAIDs that non-selectively block COX-2 protects against the development of many types of cancer.

Bortezomib, a newly approved proteasome inhibitor for the treatment of multiple myeloma: nursing implications.

Multiple myeloma (MM), a malignancy of the plasma cells, accounts for an estimated 14% of all newly diagnosed hematologic malignancies. Advances in chemotherapy and stem cell transplantation have improved survival rates, but MM remains incurable. Bortezomib (Velcade, Millennium Pharmaceuticals, Inc., Cambridge, MA), a first-in-class proteasome inhibitor, has been approved for patients with MM who have received at least two prior treatments and have demonstrated disease progression on the most recent one. During clinical trials, most side effects were manageable with standard interventions. The most common toxicities were asthenic conditions (fatigue, malaise, and weakness), gastrointestinal disturbances (nausea, vomiting, diarrhea, and constipation), thrombocytopenia, peripheral neuropathy, pyrexia, and anemia. Supportive therapies and strategies for side-effect management can prevent worsening of these symptoms, thereby avoiding dose reductions and treatment delays. Oncology nurses play a key role in ensuring the proper and safe administration of bortezomib and often are the first to identify the signs of side effects. Patient education about anticipated side effects and close monitoring of patients can lead to symptom management interventions that are essential to patient comfort and safety.

Thalidomide for patients with relapsed multiple myeloma after high-dose chemotherapy and stem cell transplantation: results of an open-label multicenter phase 2 study of efficacy, toxicity, and biological activity.

OBJECTIVES: To determine the progression-free survival at 12 weeks, to evaluate the toxic effects, and to analyze the biological activity of thalidomide in patients with relapsed multiple myeloma (MM) after high-dose chemotherapy and stem cell transplantation. PATIENTS AND METHODS: From 1999 to 2001, we performed a multicenter prospective phase 2 study in patients with MM that relapsed after high-dose chemotherapy and stem cell transplantation to evaluate the efficacy of oral thalidomide, with dose escalation from 200 to 600 mg/d over 12 weeks and a subsequent maintenance phase of 200 mg/d for up to 1 year. Outcome was correlated with serum and plasma levels of vascular endothelial growth factor and serum levels of tumor necrosis factor alpha, soluble intercellular adhesion molecule 1, interferon gamma, interleukin (IL) 2, and IL-6 during treatment. RESULTS: Thirty patients were treated (19 men and 11 women; median age, 58 years). The median number of prior therapies was 5, and the median duration from diagnosis of MM to study enrollment was 4.3 years. The 12-week progression-free survival rate was 67% (95% confidence interval [CI], 48%-86%). The observed response rate (partial response plus minor response) was 43% (95% CI, 28%-60%) with a median duration of 6 months. Attributable toxicities included constipation, fatigue, rash, and neuropathy, which was dose limiting in 8 patients (27%). Dose escalation from 200 to 600 mg/d was achieved in 50% of patients. Although responses were observed with lower doses, possibly eliminating the need to escalate the dose, responses were also seen in patients who completed the dose escalation. Some patients had disease progression while receiving the maintenance dose of 200 mg/d. Analysis of biomarker assays did not identify any biomarker associated with greater response, but a significant increase in levels of soluble intercellular adhesion molecule 1, IL-2, and interferon gamma was seen with thalidomide therapy. CONCLUSION: The optimal thalidomide dose varies, and adverse effects can be dose limiting. The dose of thalidomide therapy should be based on the individual patient to ensure that it is well tolerated and that a response is achieved.

Immunomodulatory drug CC-5013 overcomes drug resistance and is well tolerated in patients with relapsed multiple myeloma.

Thalidomide (Thal) can overcome drug resistance in multiple myeloma (MM) but is associated with somnolence, constipation, and neuropathy. In previous in vitro studies, we have shown that the potent immunomodulatory derivative of thalidomide (IMiD) CC-5013 induces apoptosis or growth arrest even in resistant MM cell lines and patient cells, decreases binding of MM cells to bone marrow stromal cells (BMSCs), inhibits the production in the BM milieu of cytokines (interleukin-6 [IL-6], vascular endothelial growth factor [VEGF], tumor necrosis factor-alpha [TNF-alpha]) mediating growth and survival of MM cells, blocks angiogenesis, and stimulates host anti-MM natural killer (NK) cell immunity. Moreover, CC-5013 also inhibits tumor growth, decreases angiogenesis, and prolongs host survival in a human plasmacytoma mouse model. In the present study, we carried out a phase 1 CC-5013 dose-escalation (5 mg/d, 10 mg/d, 25 mg/d, and 50 mg/d) study in 27 patients (median age 57 years; range, 40-71 years) with relapsed and refractory relapsed MM. They received a median of 3 prior regimens (range, 2-6 regimens), including autologous stem cell transplantation and Thal in 15 and 16 patients, respectively. In 24 evaluable patients, no dose-limiting toxicity (DLT) was observed in patients treated at any dose level within the first 28 days; however, grade 3 myelosuppression developed after day 28 in all 13 patients treated with 50 mg/d CC-5013. In 12 patients, dose reduction to 25 mg/d was well tolerated and therefore considered the maximal tolerated dose (MTD). Importantly, no significant somnolence, constipation, or neuropathy has been seen in any cohort. Best responses of at least 25% reduction in paraprotein occurred in 17 (71%) of 24 patients (90% confidence interval [CI], 52%-85%), including 11 (46%) patients who had received prior Thal. Stable disease (less than 25% reduction in paraprotein) was observed in an additional 2 (8%) patients. Therefore, 17 (71%) of 24 patients (90% CI, 52%-85%) demonstrated benefit from treatment. Our study therefore provides the basis for the evaluation of CC-5013, either alone or in combination, to treat patients with MM at earlier stages of disease.

Tumor Cell Expression of CD59 Is Associated With Resistance to CD20 Serotherapy in Patients With B-Cell Malignancies.

SUMMARY: The anti-CD20 chimeric monoclonal antibody rituximab (Rituxan) is used to treat patients with various B-cell tumors, including patients with plasma cell dyscrasias who have CD20+ disease. Many patients with CD20+ disease have either primary unresponsive disease or progress after initially responding to rituximab; therefore, understanding how tumor cells are, or become, resistant to rituximab is of clinical relevance. In this report, we determined whether tumor cells express antigens that block complement-mediated lysis or antibody-dependent cell-mediated cytotoxicity (ADCC) and thereby contribute to rituximab resistance. We demonstrate that expression of the complement regulator CD59 is associated with resistance to rituximab-mediated complement lysis of multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL) cell lines. Moreover, neutralization of CD59 using a blocking monoclonal antibody reversed resistance to rituximab-mediated complement lysis of CD20++ CD59++ ARH-77 MM cells. In addition, we demonstrate the presence of CD59 and rituximab binding on viable tumor cells from patients with MM and Waldenstrom's macroglobulinemia with progressive disease despite rituximab therapy. Last, we also examined MM and NHL B-cell lines, as well as patient tumor cells, for the expression of other antigens that may have a role in blocking ADCC activity, such as Fas ligand (FasL), MUC1, or TRAIL. FasL, MUC1, and/or TRAIL were coexpressed with complement regulators on many of these cells. These studies therefore show that complement regulators, particularly CD59 and antigens that may block ADCC, are present on various B-cell tumors and associated with rituximab resistance in patients. A prospective, clinical study is assessing the role of these antigens in mediating rituximab resistance.