Efficacy and safety of bortezomib in patients with renal impairment: results from the APEX phase 3 study

Dosing modifications of targeted cancer therapies in patients with special needs: evidence and controversies

Targeted therapies have revolutionized the treatment of malignancies over the past decade. These agents are generally regarded to posses fewer systemic side effects than traditional cytotoxic chemotherapies. However, patients manifesting organ dysfunction or drug interactions with concurrent medications may require dosing modifications of their targeted therapies in order to reduce the risk of systemic toxicities or reduction of drug efficacies. Studies have shown that wide variations and controversies exist with regard to dosing modifications of drugs, due to the lack of well conducted studies and consensus. Hence, this review was conducted to review the literature on the dosing modification strategies, for 30 commercially available targeted cancer drugs, and to evaluate the current mainstay recommendations and controversies.

Renal Insufficiency and Failure

Renal impairment is a common complication of multiple myeloma. Chronic renal failure is classified according to glomerular filtration rate as estimated by the MDRD (modification of diet in renal disease) formula, while RIFLE (risk, injury, failure, loss and end-stage renal disease) and AKIN (acute renal injury network) criteria may be used for the definition of the severity of acute renal injury. Novel criteria based on estimated glomerular filtration rate measurements are proposed for the definition of the reversibility of renal impairment. Renal complete response (CRrenal) is defined as sustained (i.e., lasting at least 2 months) improvement of creatinine clearance (CRCL) from under 50 mL/min at baseline to 60 mL/min or above. Renal partial response (PRrenal) is defined as sustained improvement of CRCL from under 15 mL/min at baseline to 30 to 59 mL/min. Renal minor response (MRrenal) is defined as sustained improvement of the baseline CRCL of under 15 mL/min to 15 to 29 mL/min or, if baseline CRCL was 15 to 29 mL/min, improvement to 30 to 59 mL/min. Bortezomib with high-dose dexamethasone is considered the treatment of choice for myeloma patients with renal impairment and improves renal function in most patients. Although there is limited experience with thalidomide, this agent can be administered at the standard dosage to patients with renal failure. Lenalidomide, when administered at reduced doses according to renal function, is effective and can reverse renal impairment in a subset of myeloma patients.

Renal Impairment in Patients With Multiple Myeloma: A Consensus Statement on Behalf of the International Myeloma Working Group

Renal impairment is a common complication of multiple myeloma (MM). The estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula is the recommended method for the assessment of renal function in patients with MM with stabilized serum creatinine. In acute renal injury, the RIFLE (risk, injury, failure, loss and end-stage kidney disease) and Acute Renal Injury Network criteria seem to be appropriate to define the severity of renal impairment. Novel criteria based on eGFR measurements are recommended for the definition of the reversibility of renal impairment. Rapid intervention to reverse renal dysfunction is critical for the management of these patients, especially for those with light chain cast nephropathy. Bortezomib with high-dose dexamethasone is considered as the treatment of choice for such patients. There is limited experience with thalidomide in patients with myeloma with renal impairment. Thus, thalidomide can be carefully administered, mainly in the context of well-designed clinical trials, to evaluate if it can improve the rapidity and probability of response that is produced by the combination with bortezomib and high-dose dexamethasone. Lenalidomide is effective in this setting and can reverse renal insufficiency in a significant subset of patients, when it is given at reduced doses, according to renal function. The role of plasma exchange in patients with suspected light chain cast nephropathy and renal impairment is controversial. High-dose melphalan (140 mg/m2) and autologous stem-cell transplantation should be limited to younger patients with chemosensitive disease.

A phase II open-label trial of bortezomib in patients with multiple myeloma who have undergone an autologous peripheral blood stem cell transplant and failed to achieve a complete response

BACKGROUND

A majority of multiple myeloma (MM) patients fail to achieve complete response (CR) to peripheral blood stem cell transplantation (PBSCT); effective options following autologous transplantation are needed. Bortezomib (B) is active against MM. This study was conducted to determine the feasibility, safety, tolerability, and efficacy of B following high-dose melphalan therapy and PBSCT. Methods Fifty patients enrolled (48 evaluable) and 49 were treated (safety population).

TREATMENT

4 cycles B 1.3 mg/m(2) Days 1, 4, 8, and 11/21-days; 4 additional cycles were permitted for stable or responding patients. Results Median age was 55 years (range, 38-73), 68% male, 64% ECOG PS = 0, 44% Durie-Salmon Stage IIIA prior to induction, 42% had symptomatic IgG MM; 74% had prior single transplant (26% tandem). Responses post-transplant: 70% PRs, 18% MRs. A median of 4 cycles (range, 2-8) of B were administered. Responses: CR 8%, uCR 2%, PR 23%, uPR 19%, MR 10%, and no change 35%; median time-to-treatment failure (TTF) was 6.2 months (range, 1.0-19.4). Three deaths occurred (n = 1 sepsis, n = 2 disease progression). Grade 3-4 treatment-related toxicities included: thrombocytopenia, neuropathy (14%, each); asthenia, neutropenia (10%, each); and nausea (4%). Twelve patients (24%) discontinued treatment due to toxicity and 30 patients (60%) completed the study; 20 patients started new treatment (median 5.8 months [range, 1.5-20.3]).

CONCLUSIONS

The study closed early due to widespread availability of B, and the lack of B-naïve patients. Bortezomib monotherapy after melphalan and autologous PBSCT was feasible, safe and well-tolerated (toxicities were manageable), but failed to produce the hypothesized response rates.

Proteasome inhibition and its therapeutic potential in multiple myeloma

Due to an unmet clinical need for treatment, the first in class proteasome inhibitor, bortezomib, moved from drug discovery to FDA approval in multiple myeloma in an unprecedented eight years. In the wake of this rapid approval arose a large number of questions about its mechanism of action and toxicity as well as its ultimate role in the treatment of this disease. In this article, we briefly review the preclinical and clinical development of the drug as the underpinning for a systematic review of the large number of clinical trials that are beginning to shed some light on the full therapeutic potential of bortezomib in myeloma. We conclude with our current understanding of the mechanism of action of this agent and a discussion of the novel proteasome inhibitors under development, as it will be progress in these areas that will ultimately determine the true potential of proteasome inhibition in myeloma.

Treatment of relapsed and refractory multiple myeloma in the era of novel agents

The introduction of the Immunomodulatory drugs (IMiDs) and proteasome inhibitors, used either as a single-agent or combined with classic anti-myeloma therapies, has improved the outcome for patients with relapsed myeloma. However, there is currently no generally accepted standard treatment for relapsed/refractory myeloma patients, partly because of the absence of trials comparing the efficacy of the novel agents in relapsed/refractory myeloma. Choice of a new treatment regimen depends on both patient and disease-specific characteristics. A lenalidomide-based regimen is the first choice in patients with neuropathy, while bortezomib has the highest efficacy in patients with renal insufficiency and is not associated with increased risk of thromboembolism. A second autologous stem cell transplantation (auto-SCT) can be applied in patients with a progression-free period of ≥ 18-24 months after the first auto-SCT. In high-risk relapse such as occurring early after auto-SCT consolidation with allogeneic SCT can be considered. In this review we provide an overview of the various salvage regimens and give recommendations for treatment of patients with relapsed/refractory myeloma in different clinical settings.

Lenalidomide in combination with dexamethasone: effective regimen in patients with relapsed or refractory multiple myeloma complicated by renal impairment

Over the past decade, treatment options for patients with multiple myeloma (MM) have improved substantially, resulting in better response rates and prolonged overall survival (OS). Nevertheless, MM remains a challenging disease, especially if renal insufficiency (RI) or extensive pre-treatment aggravates the assignment of the optimal treatment schedule. In this retrospective study, we analyzed the outcome of lenalidomide plus dexamethasone in 167 patients with relapsed or refractory MM with focus on RI. The baseline creatinine clearance (CLCr) was normal in 94 patients (CLCr≥80 ml/min), while RI was observed in 73 patients, including 40 patients with mild RI (50≤CLCr<80 ml/min) and 33 patients with moderate or severe RI (CLCr<50 ml/min). Response rates declined depending on the severity of RI, being 67% among patients with normal kidney function, 60% among patients with mild RI and 49% among patients with moderate or severe RI. Time to progression (TTP) was significantly reduced in patients with severe RI and in case of >2 previous treatment lines. OS was not significantly different between patients with normal and impaired renal function. In contrast, the number of previous treatment lines (2 vs. <2) and the use of novel agents like bortezomib or thalidomide prior to lenalidomide plus dexamethasone therapy had a more adverse effect on OS. In conclusion, lenalidomide plus dexamethasone is an effective regimen for relapsed or refractory patients with MM complicated by RI with manageable toxicity.

Kidney disease associated with plasma cell dyscrasias

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.

Primary therapy with single agent bortezomib as induction, maintenance and re-induction in patients with high-risk myeloma: results of the ECOG E2A02 trial

Single agent bortezomib results in response rates of 51% in patients with newly diagnosed multiple myeloma and is touted to be especially effective in high-risk disease. We are the first to prospectively explore single agent bortezomib as primary therapy (induction, maintenance and re-induction) without consolidative autologous stem cell transplant in a cohort selected to have high-risk multiple myeloma. Patients received eight cycles of induction, followed by maintenance bortezomib every other week, indefinitely. Patients relapsing on maintenance had the full induction schedule resumed. On an intention-to-treat basis, the response rate (>or=partial response) was 48%. Among seven patients who progressed on maintenance bortezomib and received re-induction, two responded to the treatment. With a median follow-up of 48.2 months, 1- and 2-year overall survival probabilities were 88% (95% confidence interval (CI) 79-98%) and 76% (95% CI 60-86%), respectively. Median progression-free survival was 7.9 months (95% CI 5.8-12.0). Twenty-three and thirty-four patients had >or=grade 3 hematological and non-hematological toxicity, respectively, with treatment-emergent neuropathy in 7% with motor grade 1-2, 56% with sensory grade 1-2 and 2% with grade 3, and in 14% with neuropathic pain grade 1-2 and 2% with grade 3. In high-risk patients, upfront bortezomib results in response rates that are comparable to those reported for unselected cohorts, but single agent bortezomib is not sufficient as primary therapy.

The Belgian 2010 consensus recommendations for the treatment of multiple myeloma

Since the introduction of novel therapeutic agents including thalidomide, lenalidomide and bortezomib, the prognosis of multiple myeloma (MM) has significantly improved. These agents have been incorporated into numerous treatment schedules for newly diagnosed as well as more advanced MM patients. Hence, the therapeutic options for MM have become more complex and subject to rapid changes. The multiple myeloma study group (MMSG) of the Belgian Hematological Society has established recommendations for the treatment of MM as based on an extensive review of the literature which is also summarized in this paper. The recommendations are the result of a consensus opinion between haematologists with experience in the field and representing most haematology centres in Belgium. Where applicable, reimbursement criteria are also taken into account. The consensus recommendations should be a reference for use by clinical haematologists in daily practice.

Management of treatment-related adverse events in patients with multiple myeloma

The introduction of novel antimyeloma therapies, including thalidomide, lenalidomide and bortezomib, has expanded treatment options for patients with multiple myeloma. These compounds alter the natural history of multiple myeloma and help improve outcomes, but have different and specific toxicity profiles. The major adverse events associated with these treatments are somnolence (thalidomide), venous thromboembolism (thalidomide and lenalidomide), myelosuppression (lenalidomide and bortezomib), gastrointestinal disturbance, and peripheral neuropathy (thalidomide and bortezomib). These adverse events are predictable, consistent, and manageable with patient monitoring, supportive care, and dose reduction and interruption where appropriate. Herein we evaluate the incidence of treatment-related adverse events associated with each of these compounds. We further review the management of these adverse events with a view to delivering optimal therapeutic outcomes in patients with newly diagnosed and relapsed and/or refractory multiple myeloma.

Reversibility of renal failure in newly diagnosed patients with multiple myeloma and the role of novel agents

The purpose of this analysis was to assess the effect of novel agent-based regimens on the improvement of renal impairment (RI) in newly diagnosed patients with multiple myeloma. Ninety-six consecutive patients with RI received conventional chemotherapy (CC)-based regimens (n=32), IMiDs-based regimens (n=47) or bortezomib-based regimens (n=17) as frontline therapy. Improvement of RI was more frequent in patients treated with novel agents (79% in IMiD- and 94% in bortezomib-treated groups versus 59% in CC-treated group; p=0.02). Bortezomib-based regimens and CrCl>30 ml/min at baseline independently correlated with a higher probability of at least renal partial response (PRrenal) and with a shorter time to PRrenal or better. Thus bortezomib-based regimens may be the preferred treatment for newly diagnosed myeloma patients with RI.

Advances in treatment for relapses and refractory multiple myeloma

Recent advances in the treatment of multiple myeloma have resulted in improved response rates and overall survival in patients with multiple myeloma. These advances are largely due to thalidomide-, lenalidomide-, and bortezomib-based combinations that have improved response rates, not only in patients with untreated disease, but also in those with relapsed and/or refractory myeloma, in some cases producing response rates up to 85%. Eventually, however, nearly all patients relapse, emphasizing a continuing role for the introduction of investigational agents that overcome drug resistance. This article will review the current role for thalidomide, lenalidomide, and bortezomib-based combinations, as well as some preliminary findings for promising investigational agents currently in clinical trials for patients with relapsed and/or refractory disease.

Thalidomide-dexamethasone as induction therapy before autologous stem cell transplantation in patients with newly diagnosed multiple myeloma and renal insufficiency

The aim of this study was to evaluate the efficacy and the toxicity of thalidomide-dexamethasone (Thal-Dex) as induction therapy before autologous peripheral blood stem cell (PBSC) transplantation in patients with newly diagnosed multiple myeloma (MM) with renal insufficiency. The study included 31 patients with a baseline creatinine clearance value <or=50 mL/min, 7 of whom required chronic hemodialysis. Patients received 4 months of Thal-Dex, followed by PBSC collection and subsequent transplantation. After induction, a partial response (PR) or greater was obtained in 23 patients (74%), including 8 (26%) who achieved a very good PR. Renal function improved more frequently in patients achieving a PR or greater (82%, vs 37% in patients achieving less than a PR; P = .04). Twenty-six patients underwent PBSC mobilization; in 17 of these patients (65%), >4 x 10(6) CD34(+) cells/kg were collected. Double autologous transplantation was performed in 15 patients, and a single autologous transplantation was performed in 7 patients. After a median of 32 months of follow-up, median event-free survival was 30 months, and median survival was not determined. According to our data, Thal-Dex is effective and safe in patients with newly diagnosed MM and renal insufficiency. Given the relationship between recovery of renal function and response to induction treatment, more intensive Thal + bortezomib regimens could be explored to rescue higher numbers of patients.

Reversibility of renal impairment in patients with multiple myeloma treated with bortezomib-based regimens: identification of predictive factors

PURPOSE

Renal impairment is a frequent complication of multiple myeloma (MM) and is associated with significant morbidity and increased early death rate. Bortezomib is active and well tolerated in patients with MM who present or develop renal impairment.

PATIENTS AND METHODS

We analyzed 46 consecutive patients who presented with renal impairment in order to evaluate the impact of bortezomib on the improvement of renal function and to identify predictive factors associated with renal response. All patients received bortezomib with dexamethasone with or without other agents.

RESULTS

Renal response was documented in 59% of patients within a median of 11 days (range, 8-41 days). Two of 9 patients who required dialysis became dialysis independent. A complete renal response (CRrenal) was documented in 30% of patients. Toxicities were similar to those seen in myeloma patients without renal failure who were treated with bortezomib-based regimens. Patients with light chain-only myeloma had a higher probability of achieving a renal response, and previously untreated patients had a higher probability for complete resolution of renal impairment, while light chain-only myeloma was independently associated with a shorter time to renal response. The degree of renal impairment was not predictive of the probability for renal response or CRrenal; however, in a subset of patients for whom cystatin C was available, a baseline cystatin C > 2 mg/L or cystatin C calculated estimated glomerular filtration rate < 30 mL/min were associated with a lower probability of CRrenal.

CONCLUSION

We conclude that bortezomib-based regimens may improve renal function in the majority of myeloma patients with renal impairment.

Current multiple myeloma treatment strategies with novel agents: a European perspective

The treatment of multiple myeloma (MM) has undergone significant developments in recent years. The availability of the novel agents thalidomide, bortezomib, and lenalidomide has expanded treatment options and has improved the outcome of patients with MM. Following the introduction of these agents in the relapsed/refractory setting, they are also undergoing investigation in the initial treatment of MM. A number of phase III trials have demonstrated the efficacy of novel agent combinations in the transplant and nontransplant settings, and based on these results standard induction regimens are being challenged and replaced. In the transplant setting, a number of newer induction regimens are now available that have been shown to be superior to the vincristine, doxorubicin, and dexamethasone regimen. Similarly, in the front-line treatment of patients not eligible for transplantation, regimens incorporating novel agents have been found to be superior to the traditional melphalan plus prednisone regimen. Importantly, some of the novel agents appear to be active in patients with high-risk disease, such as adverse cytogenetic features, and certain comorbidities, such as renal impairment. This review presents an overview of the most recent data with these novel agents and summarizes European treatment practices incorporating the novel agents.

VMP (Bortezomib, Melphalan, and Prednisone) Is Active and Well Tolerated in Newly Diagnosed Patients With Multiple Myeloma With Moderately Impaired Renal Function, and Results in Reversal of Renal Impairment: Cohort Analysis of the Phase III VISTA Study

Purpose

To assess bortezomib plus melphalan and prednisone (VMP) and melphalan and prednisone (MP) in previously untreated patients with multiple myeloma (MM) with renal impairment enrolled on the phase III VISTA study, and to evaluate renal impairment reversibility.

Patients and Methods

Patients received nine 6-week cycles of VMP (bortezomib 1.3 mg/m2, melphalan 9 mg/m2, prednisone 60 mg/m2) or MP. Patients with serum creatinine higher than 2 mg/dL were excluded.

Results

In the VMP/MP arms, 6%/4%, 27%/30%, and 67%/66% of patients had baseline glomerular filtration rate (GFR) of ≤ 30, 31 to 50, and higher than 50 mL/min, respectively. Response rates were higher and time to progression (TTP) and overall survival (OS) longer with VMP versus MP across renal cohorts. Response rates with VMP and TTP in both arms did not appear significantly different between patients with GFR ≤ 50 or higher than 50 mL/min; OS appeared somewhat longer in patients with normal renal function in both arms. Renal impairment reversal (baseline GFR < 50 improving to > 60 mL/min) was seen in 49 (44%) of 111 patients receiving VMP versus 40 (34%) of 116 patients receiving MP. By multivariate analysis, younger age (< 75 years; P = .006) and less severe impairment (GFR ≥ 30 mL/min; P = .027) were associated with higher reversal rates. In addition, treatment with VMP approached significance (P = .07). In both arms, rates of grade 4 and 5 adverse events (AEs) and serious AEs appeared higher in patients with renal impairment; with VMP, rates of discontinuations/bortezomib dose reductions due to AEs did not appear affected.

Conclusion

VMP is a feasible, active, and well-tolerated treatment option for previously untreated patients with MM with moderate renal impairment, resulting in 44% renal impairment reversal.

Novel agents for relapsed and/or refractory multiple myeloma

The introduction of novel agents, such as thalidomide, bortezomib, and lenalidomide, has altered the landscape of therapeutic options for multiple myeloma by offering new mechanisms for targeting this disease. Combinations of these agents, with each other and/or traditional chemotherapeutics, have vastly increased the treatment options for patients both frontline, and at relapse, providing higher response rates, and importantly, increasing median overall survival. In this review, we will discuss the use of these novel agents and their combinations in patients with relapsed and/or refractory multiple myeloma.

Safety and efficacy of bortezomib-based regimens for multiple myeloma patients with renal impairment: a retrospective study of Italian Myeloma Network GIMEMA

Renal impairment (RI) is a severe complication throughout the course of multiple myeloma (MM). Bortezomib has been shown to be highly active in MM patients with RI. We designed this retrospective analysis to investigate the safety and efficacy of bortezomib-based therapy in 117 MM patients with RI, 14 cases required dialysis. A total of 603 cycles of bortezomib were administered (median number, five cycles/patient). Ten patients required early discontinuation of bortezomib because of WHO grade IV toxicity. The rate of bortezomib discontinuation in cases with severe, moderate and mild RI was 11%, 5% and 0%, respectively (P = NS). Overall, 91 episodes of WHO grade III/IV toxicity were observed. At least a partial response was documented in 83/113 evaluable patients (73%), including complete response (19%) and near complete response (8%). The overall response rate was similar across RI subgroups. Reversal of RI was documented in 41% of patients after a median of 2.3 months (range 0.4-7.9). In three of 14 patients on dialysis, renal replacement therapy was discontinued after 1, 1 and 4 months. The 2-yr estimate of response duration and overall survival was 70% and 51%, respectively. In conclusion, bortezomib-based regimens are safe and effective and should be considered as appropriate treatment options for MM patients with any degree of RI.

Proteasome inhibitors in the treatment of multiple myeloma

Targeting intracellular protein turnover by inhibiting the ubiquitin-proteasome pathway as a strategy for cancer therapy is a new addition to our chemotherapeutic armamentarium, and has seen its greatest successes against multiple myeloma. The first-in-class proteasome inhibitor, bortezomib, was initially approved for treatment of patients in the relapsed/refractory setting as a single agent, and was recently shown to induce even greater benefits as part of rationally designed combinations that overcome chemoresistance. Modulation of proteasome function is also a rational approach to achieve chemosensitization to other antimyeloma agents, and bortezomib has now been incorporated into the front-line setting. Bortezomib-based induction regimens are able to achieve higher overall response rates and response qualities than was the case with prior standards of care, and unlike these older approaches, maintain efficacy in patients with clinically and molecularly defined high-risk disease. Second-generation proteasome inhibitors with novel properties, such as NPI-0052 and carfilzomib, are entering the clinical arena, and showing evidence of antimyeloma activity. In this spotlight review, we provide an overview of the current state of the art use of bortezomib and other proteasome inhibitors against multiple myeloma, and highlight areas for future study that will further optimize our ability to benefit patients with this disease.

Treatment of relapsed/refractory multiple myeloma

The introduction of several novel and active treatments and improvements in supportive care of myeloma patients has resulted in a prolongation of the survival of these patients. However, myeloma remains an incurable disease and almost all patients will relapse. Effective management of the relapsing/refractory disease incorporates several different strategies, depending on prior treatments, responses, and duration of responses, as well as residual toxicity, age, and physical condition. High-dose dexamethasone still has a role in the management of disease complications such as cytopenias, renal impairment, or spinal cord compression until another agent is added. High-dose therapy may be considered for selected patients who have a long-term treatment-free interval after their first transplantation. Allogeneic transplantation is limited to selected young patients, preferably with an HLA-matched donor. However, the backbone of current strategies for the management of relapsed/refractory myeloma includes the novel agents thalidomide, bortezomib, and lenalidomide. These agents, either with dexamethasone or in combination with chemotherapy, have shown significant activity both in relapsed and in refractory patients. Based on the results of phase III trials, lenalidomide and bortezomib have increased the post-relapse survival and are active in patients who have received prior novel agents; lenalidomide is active in thalidomide-pretreated or bortezomib-pretreated patients and bortezomib alone or in combination with chemotherapy is active in thalidomide/lenalidomide-pretreated patients. Combinations of novel agents show synergistic activity and may overcome drug resistance. Finally, special consideration is needed for the management of patients with renal impairment or other poor prognostic features.

Caffeic Acid Phenylethyl Ester and MG-132 Have Apoptotic and Antiproliferative Effects on Leukemic Cells But Not on Normal Mononuclear Cells

Chemotherapy aims to limit proliferation and induce apoptotic cell death in tumor cells. Owing to blockade of signaling pathways involved in cell survival and proliferation, nuclear factor kappaB (NF-kappaB) inhibitors can induce apoptosis in a number of hematological malignancies. The efficacy of conventional chemotherapeutic drugs, such as vincristine (VCR) and doxorubicine (DOX), may be enhanced with combined therapy based on NF-kappaB modulation. In this study, we evaluated the effect of caffeic acid phenylethyl ester (CAPE) and MG-132, two nonspecific NF-kappaB inhibitors, and conventional chemotherapeutics drugs DOX and VCR on cell proliferation and apoptosis induction on a lymphoblastoid B-cell line, PL104, established and characterized in our laboratory. CAPE and MG-132 treatment showed a strong antiproliferative effect accompanied by clear cell cycle deregulation and apoptosis induction. Doxorubicine and VCR showed antiproliferative effects similar to those of CAPE and MG-132, although the latter drugs showed an apoptotic rate two-fold higher than DOX and VCR. None of the four compounds showed cytotoxic effect on peripheral mononuclear cells from healthy volunteers. CAPE- and MG-132-treated bone marrow cells from patients with myeloid and lymphoid leukemias showed 69% (P < .001) and 25% decrease (P < .01) in cell proliferation and 42% and 34% (P < .01) apoptosis induction, respectively. Overall, our results indicate that CAPE and MG-132 had a strong and selective apoptotic effect on tumor cells that may be useful in future treatment of hematological neoplasias.

Treatment of patients with myeloma with comorbid conditions: considerations for the clinician

Patients with multiple myeloma (MM) frequently present with serious comorbidities such as renal impairment and/or diabetes. Treatment of these patient subsets poses a greater challenge: renal dysfunction can alter drug clearance leading to increased toxicity, and commonly used regimens can induce or exacerbate hyperglycemia. In recent years, novel targeted therapies have broadened and improved treatment options for all patients with MM. With these advancements, clinical trials are beginning to report benefit in patients with renal impairment. Furthermore, steroid-sparing and steroid-free regimens have proven highly efficacious and are predicted to improve options for patients with diabetes. This review will highlight recent trials evaluating novel regimens that promise to improve the standard of care for patients with MM with significant comorbidity.

Pathogenesis and treatment of renal failure in multiple myeloma

Renal failure is a frequent complication in patients with multiple myeloma (MM) that causes significant morbidity. In the majority of cases, renal impairment is caused by the accumulation and precipitation of light chains, which form casts in the distal tubules, resulting in renal obstruction. In addition, myeloma light chains are also directly toxic on proximal renal tubules, further adding to renal dysfunction. Adequate hydration, correction of hypercalcemia and hyperuricemia and antimyeloma therapy should be initiated promptly. Recovery of renal function has been reported in a significant proportion of patients treated with conventional chemotherapy, especially when high-dose dexamethasone is also used. Severe renal impairment and large amount of proteinuria are associated with a lower probability of renal recovery. Novel agents, such as thalidomide, bortezomib and lenalidomide, have significant activity in pretreated and untreated MM patients. Although there is limited experience with thalidomide and lenalidomide in patients with renal failure, data suggest that bortezomib may be beneficial in this population. Clinical studies that have included newly diagnosed and refractory patients indicate that bortezomib-based regimens may result in rapid reversal of renal failure in up to 50% of patients and that full doses of bortezomib can be administered without additional toxicity.