Effective treatment of advanced multiple myeloma refractory to alkylating agents

The role of bortezomib, thalidomide and lenalidomide in the management of multiple myeloma: an overview of clinical and economic information

Bortezomib, thalidomide and lenalidomide can be aimed at treating patients with newly diagnosed multiple myeloma (both eligible and ineligible for transplantation) as well as those with relapsed or refractory disease. This review analysed the available clinical and economic data on these three drugs. Irrespective of which of the three agents is considered, the magnitude of the benefit in newly diagnosed cases (transplanted or non-transplanted) tends to be between 10 and 20 months per patient in terms of progression-free survival or survival; the survival benefit is smaller in relapsed or refractory disease. In addition, a single-institution observational analysis evaluated the outcomes in nearly 3000 consecutive patients examined between 1971 and 2006. The survival in patients diagnosed between 2001 and 2006 was longer than that observed in patients diagnosed between 1994 and 2000. This finding supports the conclusion that novel agents provide a survival improvement compared with traditional therapy. Formal cost-effectiveness studies on these three agents are still lacking. A MEDLINE search retrieved only four short papers or letters and no full-length analysis. Hence, the cost effectiveness of these agents needs further investigation, with separate assessments of the different therapeutic settings. In a simplified analysis, we tried to contrast the average cost of treatment for each of the novel agents versus their respective benefit, expressed in quality-adjusted survival. Despite its preliminary nature, our assessment indicates that the cost effectiveness of these three agents is likely to be within commonly accepted pharmacoeconomic thresholds.

High-dose glucocorticoids improve renal failure reversibility in patients with newly diagnosed multiple myeloma

One-fifth of the newly diagnosed multiple myeloma (MM) patients present with renal failure (RF) [1-3]. Glucocorticoids (GCs) may improve RF in MM by (1) rapid reduction of paraprotein production, (2) lessening inflammation and fibrosis in renal parenchyma, and (3) decreasing serum calcium level. We hypothesized that lower dose GCs may be less effective in restoring renal function and retrospectively compared the RF reversibility between the newly diagnosed MM patients who were treated with GCs equivalent to ≥160 mg DX over 4 days (high-dose GC group, n = 16) versus those who were treated with <160 mg (low-dose/no GC group, n = 8). There was no difference in age, baseline calcium, and creatinine levels between the two groups. Renal function was restored in seven patients in the high-dose GC group (44%) and in none of the patients in the low-dose/no GC group (P = 0.026). The only other factor found to impact the RF reversibility was the delay of GC initiation. Four and 1 patients developed a severe infection in the high- and low-dose/no GC groups, respectively. The use of higher dose GCs in the newly diagnosed MM patients who present with RF increases the likelihood of renal function restoration.

Melphalan-prednisolone and vincristine-doxorubicin-dexamethasone chemotherapy followed by prednisolone/interferon maintenance therapy for multiple myeloma: Japan Clinical Oncology Group Study, JCOG0112

A multicenter phase III study for untreated multiple myeloma was conducted to investigate a switch-induction chemotherapy with melphalan-prednisolone and vincristine-doxorubicin-dexamethasone followed by randomization on maintenance therapy for patients achieving plateau. Between November 2002 and November 2005, 34 patients were registered. The study was closed early because of poor accrual. Thirty-three eligible patients, with a median age of 65 years (range: 47-77 years) were analyzed for the secondary purpose. For induction therapy, 16 patients were treated with vincristine-doxorubicin-dexamethasone and 17 with melphalan-prednisolone initially. In eight cases, induction therapy was switched because of a poor response. Both regimens were well tolerated, but neutropenia, anorexia, constipation and infection with neutropenia were more frequent for vincristine-doxorubicin-dexamethasone. Best response rates were 44% (95% confidence interval, 20-70) and 47% (95% confidence interval, 23-72), respectively, for vincristine-doxorubicin-dexamethasone and melphalan-prednisolone. Vincristine-doxorubicin-dexamethasone/melphalan-prednisolone switch-induction therapy might be feasible and effective for Japanese patients with multiple myeloma.

Dual role of nanoparticles as drug carrier and drug

The conventional chemotherapeutic agents used in the treatment of human malignancies are directed nonspecifically against both malignant and nonmalignant cells, often limiting their efficacy with having serious side effects. Recent development of drug delivery vehicles has opened up the possibility of targeted drug delivery systems with the potential of achieving maximum efficacy with minimal toxicity. The possibility of using a nanomaterial as a combinational drug component is intuitively evident as it would compensate the toxicity level by enhancing drug delivery efficiency. Additionally, cell-specific cytotoxicity (reported earlier by our group) of the nanovehicle itself may potentiate a more effective targeted cell killing. In this paper, we explore the possibility of using gold nanoparticles playing the dual role of an anticancer agent and a carrier of a chemotherapeutic drug. This is demonstrated using vincristine sulfate (VS), salt of an alkaloid often used in the treatment of multiple myeloma (MM), and U266 as a test MM cell line. The drug VS shows the expected G2-M-phase arrest of cells. Notably, bare gold nanoparticle shows arrest of the S phase cells that may be particularly important in case of slow-growing malignancies like MM where most of the cells remain in G1 phase of the cell cycle. The VS conjugated gold retains the activity of both gold nanoparticle and VS leading to a synergistic rise of the apoptotic cell population.

Therapy of relapsed and refractory multiple myeloma

Despite considerable improvements in first line treatment still the majority of patients experience relapse of multiple myeloma. Treatment decisions for relapse or refractory multiple myeloma should be based on a clinical decision path taking response and adverse events to previous therapy, myeloma specific complications and organ dysfunctions, overall clinical condition, age, cytogenetic information and prognostic factors into account. Bortezomib, thalidomide and lenalidomide have improved the therapeutic armentarium for patients with refractory or relapsed disease and are often used in combination with dexamethasone or chemotherapeutic agents. Combination therapies of novel agents in drug combination regimen are currently under investigation as well. For patients with a disease free survival of 12 month or longer after initial single or tandem high dose therapy and autologous stem cell transplantation (ASCT) repeat of high dose therapy with melphalan and ASCT should be considered in case of relapse. Radiotherapy and osteoplastic procedures can be used as adjunct to systemic therapy to treat local complications in particular vertebral pain caused by osteolytic bone disease. Cytogenetic tests, molecular techniques as gene expression profiling and other diagnostic will lead to a more individualized therapy. The integration of novel compounds into established regimen will be a major challenge for future clinical studies.

Reduced risk of bacterial infection in multiple myeloma patients with VAD regimen without intermittent high-dose dexamethasone

Vincristine-adriamycin-dexamethasone (VAD) regimen with intermittent high-dose dexamethasone (HD) has been used as primary chemotherapy for multiple myeloma (MM) patients who are candidates for high-dose therapy or present with renal failure. However, dexamethasone increases the risk of infection in MM patients. We retrospectively evaluated treatment efficacy and infectious events in MM patients undergoing VAD with or without HD. Seventy-seven consecutive patients who received VAD without HD (n = 37) or VAD-HD (n = 40) at our institution were assessed. Characteristics of patients and VAD regimens were retrospectively analyzed to detect correlations with the incidence of infections. During 218 VAD cycles, 48 infectious episodes were documented in 39 patients. Of these, 32 episodes in 26 patients were severe (grade ≥ 3). By analyzing each patient, VAD-HD was associated with risk of all-grade and severe bacterial infection, while International Staging System stage ≥ 2 was independently correlated with severe bacterial infection. Response rates after two cycles were comparable between the 2 VAD regimens. In conclusion, risk of infection is lower in VAD without HD than in VAD-HD, and the clinical response is equivalent. VAD-HD should thus be avoided for MM patients with high risk of infection.

Newly diagnosed multiple myeloma in Taiwan: the evolution of therapy, stem cell transplantation and new treatment agents

Multiple myeloma is a clonal plasma cell dyscrasia with clinical heterogeneity. As of now, two key questions need to be answered before starting to treat a newly diagnosed myeloma patient. One is whether the patient is a candidate for high-dose chemotherapy with stem cell support and the other is risk stratification. As novel therapeutics have emerged, it is increasingly important to introduce a risk-adapted approach. The heterogeneity of the disease is established, for the most part, by disease biology, predominantly genetics. Cytogenetic analysis by either banding technique or fluorescent in situ hybridization is able to identify high-risk subpopulations. The new international staging system based on beta2-microglobulin and albumin levels in serum is also very helpful in defining the high-risk group (stage 3). This group of patients may not respond well to high-dose chemotherapy and require early introduction of newer treatments such as the bortezomib-containing regimen. The main factor in determining the eligibility for stem cell transplants is age. Based on the current literature and situation in Taiwan, we suggest stem cell transplantation if the patient is younger than 55 years of age. Each case should be considered individually if the age of the patient is between 55 and 70 years. Finally, we have also reviewed the status and the treatment of multiple myeloma in Taiwan. Fortunately, there has been an improvement in awareness, diagnosis and treatment. Cytogenetic studies have been applied in risk evaluations, but are limited in a few centers due to lack of availability. With the exception of the agent lenalidomide, new novel agents are available for treating of myeloma in Taiwan.

High complete remission rate and durable remissions achieved with rational use of autologous stem-cell transplantation, thalidomide maintenance, and non-myeloablative allogeneic transplantation in patients with multiple myeloma

Autologous stem-cell transplantation (ASCT) has emerged as the standard approach in patients with multiple myeloma, although it is unlikely to achieve cure. Thalidomide maintenance and non-myeloablative allogeneic transplantation (NST) may increase complete remission (CR) rate and increase overall survival. In this study, 35 ASCT and 10 NST were performed in 33 patients. Patients, who were resistant or relapsed following ASCT, underwent NST if they had an HLA-matched sibling, otherwise treated with a second ASCT. Thalidomide was started as maintenance after ASCT. After first transplantation, three patients underwent second ASCT and 10 patients underwent NST. Following first transplantation, CR rate was 39% and increased to 60% (overall response 93%) with addition of thalidomide, bortezomib, and second transplantation. CR was durable in 14 (42%) patients. During a median follow-up of 24 months, 18 patients progressed and nine patients died. The 100-d transplant-related mortality was <5%. The four-yr progression-free survival (PFS) was 52.4%. In conclusion, ASCT followed by thalidomide and NST in resistant patients can lead to high CR and PFS rates. As a second transplantation has not been performed routinely, patients having durable CR had a chance to avoid or delay a second transplantation without compromising disease control.

Concurrent p16 methylation pattern as an adverse prognostic factor in multiple myeloma: a methylation-specific polymerase chain reaction study using two different primer sets

Disruption of cell cycle control genes, including p16, is known to contribute to the cancerogenesis of multiple myeloma (MM). We investigated the methylation status of p16 and its association with common cytogenetic changes, clinicolaboratory findings, and survival in MM. Methylation-specific polymerase chain reaction was performed in 99 newly diagnosed MM patients using two different sets of primers (p16M1 and p16M2). Four patterns of p16 promoter methylation were observed: (1) concurrent methylation of p16M1 and p16M2 (P1P2), 27.3%; (2) methylation of p16M1 alone (P1N2), 7.1%; (3) methylation of p16M2 alone (N1P2), 26.3%; and (4) no methylation (N1N2), 39.4%. Patients with p16P1P1 showed shorter survivals than those with the other methylation patterns (P1N2, N1P2, or N1N2; median survival, 12 vs. 43 months; P < 0.001), regardless of the treatment protocol. In a multivariate analysis, p16P1P2 was an independent prognostic factor of adverse outcome in MM. According to International Staging System (ISS), the study population could be divided into 21.2% (20/94) for stage I, 22.3% (21/94) for stage II, and 56.4% (53/94) for stage III (P = 0.003). ISS can divide patients into prognostic groups. Of note, in patients older than 60 years, ISS was not reflective of disease stage (P = 0.114). If p16P1P2 sets up as stage 4 of ISS, modified ISS could be a more reliable staging system irrespective of age in Korean MM patients (P = 0.003 and P = 0.004 in patients younger than 60 years and in patients older than 60 years, respectively). Our study suggests the potential use of p16 methylation status in predicting the outcome of MM patients and the applicability of demethylating agents in MM.

Treatment of multiple myeloma: a comprehensive review

Multiple myeloma (MM) is a neoplastic plasma cell disorder that results in end-organ damage (hypercalcemia, renal insufficiency, anemia, or skeletal lesions). Patients should not be treated unless they have symptomatic (end-organ damage) MM. They should be classified as having high-risk or standard-risk disease. Patients are classified as high risk in the presence of hypodiploidy or deletion of chromosome 13 (del[13]) with conventional cytogenetics, the presence of t(4:14), t(14;16), t(14;20) translocations or del(17p) with fluorescence in situ hybridization. High-risk disease accounts for about 25% of patients with symptomatic MM. If the patient is deemed eligible for an autologous stem cell transplantation (ASCT), 3 or 4 cycles of lenalidomide and low-dose dexamethasone, or bortezomib and dexamethasone, or thalidomide and dexamethasone are reasonable choices. Stem cells should then be collected and one may proceed with an ASCT. If the patient has a complete response or a very good partial response (VGPR), the patient may be followed without maintenance therapy. If the patient has a less than VGPR, a second ASCT is encouraged. If the patient is in the high-risk group, a bortezomib-containing regimen to maximum response followed by 2 additional cycles of therapy is a reasonable approach. Lenalidomide and low-dose dexamethasone is another option for maintenance until progression. If the patient is considered ineligible for an ASCT, then melphalan, prednisone, and thalidomide is suggested for the standard-risk patient, and melphalan, prednisone, and bortezomib (MPV) for the high-risk patient. Treatment of relapsed or refractory MM is covered. The novel therapies-thalidomide, bortezomib, and lenalidomide-have resulted in improved survival rates. The complications of MM are also described. Multiple myeloma is a plasma cell neoplasm that is characterized by a single clone of plasma cells producing a monoclonal protein (M-protein). The malignant proliferation of plasma cells produces skeletal destruction that leads to bone pain and pathologic fractures. The M-protein might lead to renal failure, hyperviscosity syndrome, or through the suppression of uninvolved immunoglobulins, recurrent infections. Anemia and hypercalcemia are common complications.

Impact of dexamethasone responsiveness on long term outcome in patients with newly diagnosed multiple myeloma

Dexamethasone (Dex), alone or in combination, is commonly used for treating multiple myeloma. Dex as single agent for initial therapy of myeloma results in overall response rates of 50-60%. It is unclear whether steroid responsiveness reflects any biological characteristic that impacts long-term outcome. We studied a cohort of 182 patients with newly diagnosed myeloma seen between March 1998 and June 2007, initially treated with single-agent Dex for at least 4 weeks. The median age at diagnosis was 63 years (range, 39-81) and the median estimated survival was 55 months. At a median duration of therapy of 15 weeks, 91 (50%) patients had a partial response or better, 80 (44%) had less than partial response and the remaining (6%) patients were not evaluable. The median overall survival from diagnosis for the responders was 75 months compared to 71 months for remaining patients, P = 0.6.There was no correlation between baseline disease characteristics and Dex responsiveness. While overall survival was longer for the 130 (70%) patients who proceeded to an autologous stem cell transplant, no correlation was found between survival and Dex responsiveness among either group. Among this cohort of patients with myeloma, failure to respond to single agent steroid did not have an adverse impact on eventual outcome.

Management of newly diagnosed symptomatic multiple myeloma: updated Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus guidelines

Multiple myeloma is a malignant plasma cell neoplasm that affects more than 20,000 people each year and is the second most common hematologic malignancy. It is part of a spectrum of monoclonal plasma cell disorders, many of which do not require active therapy. During the past decade, considerable progress has been made in our understanding of the disease process and factors that influence outcome, along with development of new drugs that are highly effective in controlling the disease and prolonging survival without compromising quality of life. Identification of well-defined and reproducible prognostic factors and introduction of new therapies with unique modes of action and impact on disease outcome have for the first time opened up the opportunity to develop risk-adapted strategies for managing this disease. Although these risk-adapted strategies have not been prospectively validated, enough evidence can be gathered from existing randomized trials, subgroup analyses, and retrospective studies to develop a working framework. This set of recommendations represents such an effort-the development of a set of consensus guidelines by a group of experts to manage patients with newly diagnosed disease based on an interpretation of the best available evidence.

The development and pharmacology of proteasome inhibitors for the management and treatment of cancer

The ubiquitin-proteasome complex is an important molecular target for the design of novel chemotherapeutics. This complex plays a critical role in signal transduction pathways important for tumor cell growth and survival, cell-cycle control, transcriptional regulation, and the modulation of cellular stress responses to endogenous and exogenous stimuli. The sensitivity of transformed cells to proteasome inhibitors and the successful design of treatment protocols with tolerable, albeit narrow, therapeutic indices have made proteasome inhibition a viable strategy for cancer treatment. Clinical validation of the proteasome as a molecular target was achieved with the approval of bortezomib, a boronic acid proteasome inhibitor, for the treatment of multiple myeloma and mantle cell lymphoma. Several "next-generation" proteasome inhibitors (carfilzomib and PR-047, NPI-0052, and CEP-18770) representing distinct structural classes (peptidyl epoxyketones, beta-lactones, and peptidyl boronic acids, respectively), mechanisms of action, pharmacological and pharmacodynamic activity profiles, and therapeutic indices have now entered clinical development. These agents may expand the clinical utility of proteasome inhibitors for the treatment of solid tumors and for specific non-oncological, i.e., inflammatory disease, indications as well. This chapter addresses the biology of the proteasome, the medicinal chemistry and mechanisms of action of proteasome inhibitors currently in clinical development, the preclinical and clinical pharmacological and safety profiles of bortezomib and the newer compounds against hematological and solid tumors. Future directions for research and other applications for this novel class of therapeutics agents are considered in this chapter.

Lenalidomide plus high-dose dexamethasone versus lenalidomide plus low-dose dexamethasone as initial therapy for newly diagnosed multiple myeloma: an open-label randomised controlled trial

BACKGROUND

High-dose dexamethasone is a mainstay of therapy for multiple myeloma. We studied whether low-dose dexamethasone in combination with lenalidomide is non-inferior to and has lower toxicity than high-dose dexamethasone plus lenalidomide.

METHODS

Patients with untreated symptomatic myeloma were randomly assigned in this open-label non-inferiority trial to lenalidomide 25 mg on days 1-21 plus dexamethasone 40 mg on days 1-4, 9-12, and 17-20 of a 28-day cycle (high dose), or lenalidomide given on the same schedule with dexamethasone 40 mg on days 1, 8, 15, and 22 of a 28-day cycle (low dose). After four cycles, patients could discontinue therapy to pursue stem-cell transplantation or continue treatment until disease progression. The primary endpoint was response rate after four cycles assessed with European Group for Blood and Bone Marrow Transplant criteria. The non-inferiority margin was an absolute difference of 15% in response rate. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00098475.

FINDINGS

445 patients were randomly assigned: 223 to high-dose and 222 to low-dose regimens. 169 (79%) of 214 patients receiving high-dose therapy and 142 (68%) of 205 patients on low-dose therapy had complete or partial response within four cycles (odds ratio 1.75, 80% CI 1.30-2.32; p=0.008). However, at the second interim analysis at 1 year, overall survival was 96% (95% CI 94-99) in the low-dose dexamethasone group compared with 87% (82-92) in the high-dose group (p=0.0002). As a result, the trial was stopped and patients on high-dose therapy were crossed over to low-dose therapy. 117 patients (52%) on the high-dose regimen had grade three or worse toxic effects in the first 4 months, compared with 76 (35%) of the 220 on the low-dose regimen for whom toxicity data were available (p=0.0001), 12 of 222 on high dose and one of 220 on low-dose dexamethasone died in the first 4 months (p=0.003). The three most common grade three or higher toxicities were deep-vein thrombosis, 57 (26%) of 223 versus 27 (12%) of 220 (p=0.0003); infections including pneumonia, 35 (16%) of 223 versus 20 (9%) of 220 (p=0.04), and fatigue 33 (15%) of 223 versus 20 (9%) of 220 (p=0.08), respectively.

INTERPRETATION

Lenalidomide plus low-dose dexamethasone is associated with better short-term overall survival and with lower toxicity than lenalidomide plus high-dose dexamethasone in patients with newly diagnosed myeloma.

FUNDING

National Cancer Institute, Rockville, MD, USA.

The use of novel agents in the treatment of relapsed and refractory multiple myeloma

Although outcomes for patients with multiple myeloma (MM) have improved over the past decade, the disease remains incurable and even patients who respond well to induction therapy ultimately relapse and require additional treatment. Conventional chemotherapy and high-dose therapy with stem cell transplantation (SCT) have historically been utilized in the management of relapsed MM, but in recent years the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, as well as the proteasome inhibitor bortezomib, have assumed a primary role in this setting. This review focuses on the role of thalidomide, lenalidomide and bortezomib in relapsed and refractory MM, with additional discussion dedicated to emerging drugs in relapsed MM that may prove beneficial to patients with this disease.

Bortezomib in the management of multiple myeloma

Multiple myeloma (MM) is a B-cell malignancy characterized by clonal expansion of plasma cells within the bone marrow, the presence of a serum and/or urine monoclonal protein, lytic bone lesions, and anemia. On a cellular level, the disease is characterized by complex interactions between tumor cells and the surrounding bone marrow microenvironment. Understanding of the relationship between malignant plasma cells and the microenvironment has sparked ongoing efforts to develop targeted therapeutic agents for treatment of this disease. The successful development of the first-in-class small-molecule proteasome inhibitor bortezomib occurred as a result of these efforts. This review focuses on the rationale for bortezomib therapy in the treatment of patients with newly diagnosed and relapsed MM, important treatment-related side effects, and future directions for use of bortezomib and other, emerging proteasome inhibitors.

Multiple myeloma

Multiple myeloma is characterised by clonal proliferation of malignant plasma cells, and mounting evidence indicates that the bone marrow microenvironment of tumour cells has a pivotal role in myeloma pathogenesis. This knowledge has already expanded treatment options for patients with multiple myeloma. Prototypic drugs thalidomide, bortezomib, and lenalidomide have each been approved for the treatment of this disease by targeting both multiple myeloma cells and the bone marrow microenvironment. Although benefit was first shown in relapsed and refractory disease, improved overall response, duration of response, and progression-free and overall survival can be achieved when these drugs are part of first-line regimens. This treatment framework promises to improve outcome not only for patients with multiple myeloma, but also with other haematological malignancies and solid tumours.

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.

Successful mobilization of peripheral blood stem cells with bortezomib + high-dose cyclophosphamide + G-CSF in a light chain myeloma patient after failure with Total Therapy 2

Autologous stem cell transplantation is considered the best post-induction therapy for multiple myeloma (MM). Therefore, therapy for myeloma should be chosen not only on the basis of efficacy, but also taking into account their impact on the hematopoietic stem cell compartment. We describe the case of a MM patient in which a successful mobilization of peripheral stem cells was obtained with bortezomib, cyclophosphamide and G-CSF, after two failed attempts in the framework of Total Therapy 2. The patient underwent an autologous transplantation, showing a rapid and complete post-transplant hematological recovery. Our experience suggests that bortezomib is an effective anti-myeloma agent without negative impact on stem cell mobilization, even in patients with a previous history of failed harvest.

Emerging therapies for multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell malignancy clinically characterized by osteolytic lesions, immunodeficiency, and renal disease. There are an estimated 750,000 people diagnosed with MM worldwide, with a median overall survival of 3 - 5 years. Besides chromosomal aberrations, translocations, and mutations in essential growth and tumor-suppressor genes, accumulating data strongly highlight the pathophysiologic role of the bone marrow (BM) microenvironment in MM pathogenesis. Based on this knowledge, several novel agents have been identified, and treatment options in MM have fundamentally changed during the last decade. Thalidomide, bortezomib, and lenalidomide have been incorporated into conventional cytotoxic and transplantation regimens, first in relapsed and refractory and now also in newly diagnosed MM. Despite these significant advances, there remains an urgent need for more efficacious and tolerable drugs. Indeed, a plethora of preclinical agents awaits translation from the bench to the bedside. This article reviews the scientific rationale of new therapy regimens and newly identified therapeutic agents - small molecules as well as therapeutic antibodies - that hold promise to further improve outcome in MM.

High-dose chemotherapy and autologous bone marrow transplantation for myeloma

In three studies we have attempted to increase the complete remission rate in a series of patients with multiple myeloma under the age of 69. A CR rate of 27% was seen in 63 patients treated with intravenous high-dose melphalan 140 m/m2 with or without the addition of high-dose methyl prednisolone 1 g/m2 for 5 days (in 22 patients). In a third study a CR rate of 50% was seen in 50 patients treated in a programme in which vincristine, adriamycin and methyl prednisolone was first given and patients then received high-dose melphalan 140-200 mg/m2 with an autologous bone marrow transplant where possible. Median remission duration in the first two studies was 19 months with a median survival of 5 years. A definition of complete remission in myeloma is proposed.

Autologous bone marrow transplantation therapy for multiple myeloma

We have begun an autologous bone marrow transplantation (ABMT) treatment protocol for patients with myeloma who achieve a minimal disease (less than 10% marrow plasma cells) status. Sites of bony disease are irradiated before BMT. Melphalan 70 mg/m2 on days 1 and 2 is followed by 1200 rads total-body irradiation administered in fractionated doses over 3 d. Autologous marrow which has been previously treated with anti-CALLA, B1, and PCA-1 monoclonal antibodies is then thawed and reinfused. 4 males and 2 females with median age of 46 yr (41-56) have been treated. Granulocytes greater than 500/mm3 and platelets greater than 20,000/mm3 were noted at 21 (12-46) and 23 (12-53) d post-transplant (PT), respectively. Acute mucositis and dermatomal Herpes zoster developed in 3 patients each; all patients are clinically well at 233 (30-807) d PT. All patients achieved pathologically normal marrows, but monoclonal plasma cells and marrow myelofibrosis were each noted in a single patient at 486 and 272 d PT, respectively. A single patient has responded to alpha 2 interferon therapy PT; all others have received no therapy. AMBT offers an exciting new treatment for myeloma; however, relapses post-ABMT suggest that improved ablative regimens and/or marrow purging methods may be required.

Chemotherapy for resistant and relapsing multiple myeloma

This report summarizes a broad experience in the treatment of patients with multiple myeloma resistant to standard chemotherapy. The VAD regimen has induced remissions in about 50% of relapsing patients but in only about 25% of previously unresponsive patients. In patients resistant to VAD, high-dose therapies with intravenous melphalan, a CBV combination (cyclophosphamide-BCNU-VP-16) or an EDAP regimen (VP-16 -platinum) produced responses in about 40% of patients. However, these treatments usually required autologous bone marrow or blood stem cell support and the median duration of control was only 6 months. With an even more intensive program using high-dose melphalan and total body irradiation supported by autologous bone marrow, all patients who survived the early treatment period responded for a median duration of about 1 year. Results indicated a dose-response effect of chemoradiotherapy on VAD-resistant myeloma with the potential that such intensive regimens will prolong disease-free survival time.

Role of combination bortezomib and pegylated liposomal doxorubicin in the management of relapsed and/or refractory multiple myeloma

The first in class proteasome inhibitor bortezomib (B) received its initial regulatory approval for therapy of patients with multiple myeloma (MM) in the relapsed/refractory setting. Modulation of proteasome function, however, is also a rational strategy for chemosensitization, and a variety of agents have shown synergistic activity with bortezomib pre-clinically, including anthracyclines. This formed the basis for evaluation of a regimen of bortezomib with pegylated liposomal doxorubicin (PLD). PLD+B, in a phase I study, induced a predictable and manageable toxicity profile, and showed encouraging anti-MM activity. In a recent international, randomized phase III trial, PLD+B demonstrated a superior overall response rate and response quality compared to bortezomib alone, as well as a longer time to progression, duration of response, progression-free survival, and overall survival. Sub-analyses revealed benefits in almost all clinically relevant subgroups, including several which would be considered to have high-risk disease. These findings have led to the establishment of the PLD+B regimen as one of the standards of care for patients with relapsed and/or refractory myeloma. Efforts are now underway to build on this combination further by adding other active anti-myeloma agents. In this review, we will discuss the role of PLD+B as an important addition to our therapeutic armamentarium for patients with MM.

Initial therapy in multiple myeloma: investigating the new treatment paradigm

The development of three novel chemotherapeutic agents - thalidomide, lenalidomide, and bortezomib - has resulted in a fundamental shift in the management of multiple myeloma. Despite this tremendous advancement, the selection of initial treatment must still be made with a degree of uncertainty as a true standard therapy has yet to be established. Although challenging, the relative abundance of therapeutic options, when taken into consideration with unique patient characteristics, creates the potential for individualization of care.For patients eligible for autologous stem cell transplantation, various combinations of novel agents with dexamethasone or traditional chemotherapy have supplanted the previous standard regimen consisting of vincristine, doxorubicin, and dexamethasone. In elderly patients or others that are deemed ineligible for the transplant procedure, the addition of a novel agent to melphalan-prednisone has demonstrated significant improvements in response rates. Due to the immaturity of the available data, it is perhaps best to regard the era of novel agents with a degree of rational enthusiasm, as the ultimate impact on patient care remains undetermined. Although further research is clearly implicated, recent advancements have resulted in significant progress toward obtaining optimum outcomes in a historically challenging disease.

The role of high-dose chemotherapy followed by peripheral blood stem cell transplantation for the treatment of multiple myeloma

The management of multiple myeloma has changed significantly over the past 10 years. The results obtained with conventional chemotherapy were disappointing; however the use of high dose therapy (HDT) and stem cell transplantation has significantly improved survival. Autologous, allogeneic and tandem transplantation, along with different conditioning regimens, have been studied in an attempt to optimise and further improve outcomes. This review summarises the role of stem cell transplantation in multiple myeloma. The advent of novel therapies such as thalidomide, lenalidomide and bortezomib have started to redefine the role of peripheral stem cell transplantation, however, further study is needed to better understand how to most effectively use these agents in multiple myeloma in conjunction with HDT.

Current Trends in Multiple Myeloma Management

Treatment of multiple myeloma, a B-cell cancer, is usually palliative, however, as a result of intensive clinical research there are numerous new treatment options available today. The present review summarizes non-transplant treatment options for multiple myeloma on the basis of available publications. Treatment with new substances, such as immunomodulatory agents, farnesyl transferase inhibitors and apoptosis stimulators, and their mechanisms of action are discussed. In addition to this systematic review of the available evidence on multiple myeloma therapy we have also summarized current recommendations from national and international organizations on aspects of the treatment of multiple myeloma. This should enable readers to see different points of view at a glance and, hopefully, will provide a basis for translation of the available evidence into the best possible therapy.

Eight-year median survival in multiple myeloma after total therapy 2: roles of thalidomide and consolidation chemotherapy in the context of total therapy 1

In comparison to total therapy 1 (TT1), the phase 3 trial total therapy 2 (TT2) evaluated the benefit of up-front administration of thalidomide (THAL); TT2 also introduced post-transplant consolidation chemotherapy. With median follow-up times of 5 and 12 years, respectively, outcome comparisons were made of 668 patient's enrolled on TT2 and 231 patients treated on TT1. Complete response (CR) rates were similar at 40% for TT1 and TT2 without THAL versus 60% on the THAL arm of TT2. CR durations were similar with either TT2 arm and both were superior to results of TT1. Event-free and overall survivals were extended from 2.6 to 5.7 years, respectively, with TT1 to 4.8 and 8.0 years with TT2. TT2's major advance vis-à-vis TT1 pertained to the subgroup without cytogenetic abnormalities (CA), supporting the role of post-transplant consolidation therapy, whereas the improved survival of the CA subgroup on the experimental versus control arm of TT2 attests to the role of THAL in this setting. Adjusting for prognostic variables in multivariate and pair-mate analyses, TT2 was superior to TT1 in terms of CR duration, event-free and overall survival. These results provide a basis for the prospective evaluation of the consolidation strategy in a randomized clinical trial design.

Impact of pretransplant therapy in patients with newly diagnosed myeloma undergoing autologous SCT

Autologous SCT (ASCT) remains an effective therapy for eligible patients with myeloma. Previous studies have suggested a lack of impact of the initial therapy on the outcome after ASCT. It is not clear if incorporation of new agents in the initial treatment regimens will have any impact on the outcome after ASCT. We studied 472 patients undergoing ASCT within 12 months of diagnosis to assess the effect of initial therapy on the outcome after ASCT. Patients received initial therapy with vincristine, adriamycin and dexamethasone (VAD), dexamethasone, thalidomide and dexamethasone or lenalidomide and dexamethasone. While patients treated with dexamethasone alone had higher disease burden at ASCT, no differences were observed in the response rates to ASCT, post transplant complications or treatment-related mortality among the groups. The median time to progression after ASCT was 27.1, 24.7, 21.1 months and did not reach the VAD, Dex, Thal-Dex and Len-Dex group, respectively, P=0.11. The median overall survival from ASCT was 62 months for VAD, 69.6 months for Dex and were not reached for Thal-Dex and Len-Dex groups, P=0.2. For patients undergoing early ASCT for myeloma, the nature of initial treatment utilized has no long-term impact on the outcome of ASCT.

Management of relapsed and relapsed refractory myeloma

Studies of bortezomib, thalidomide, and lenalidomide have shown promising clinical activity in relapsed/refractory multiple myeloma (MM). Bortezomib alone and in combination with other agents is associated with high response rates, consistently high rates of complete response, and a predictable and manageable profile of adverse events. Thalidomide-based regimens have also shown substantial clinical activity. The accumulating experience from ongoing trials of bortezomib/lenalidomide/dexamethasone combinations in patients who have relapsed/refractory or newly diagnosed MM will provide critical information that will determine the possible role of this combination as the basic backbone for combination regimens for management of advanced MM.

Thirty patients with primary plasma cell leukemia: a single center experience

The primary plasma cell leukemia (PCL) is a rare aggressive plasma cell dyscrasia. We investigated its clinical and laboratory aspects in a large series of patients. Among 934 consecutive patients with multiple myeloma (MM), registered between 1978 and 2004 in a single institution, 30 patients [M/F: 22/8; median age (yr): 60, range: 36-79] with PCL (3.1%) were diagnosed. Retrospective analysis of the clinical, immunophenotypic, and cytogenetic aspects was performed. All patients had anemia, thrombocytopenia, circulating plasma cells (median count 4 x 10(9)/l), and in 18/30 patients hypercalcemia was found. Extramedullar involvement was present in 18/30 (60%) patients. The plasma cells were CD138+ and CD38+ (9/9), CD20+ (1/9), and CD10+ (1/9) with cytoplasmic positivity for light chains (9/9). The cytogenetic studies, evaluable in 21/30 patients, showed normal karyotype (6/21), complex hypodiploidy (6/15), pseudodiploidy (5/15), and hyperdiploidy (4/15). Treatment modalities had no impact on survival (median 4.5 months). Seven patients achieved remission. The performance status (ECOG >or= 2), platelet count <or= 100 x 10(9)/l, and serum LDH value >or= 460 U/l were independent prognostic parameters of survival. The immunologic and cytogenetic presentation of patients with PCL bears little significance on prognosis, which is heavily compromised by advanced age at diagnosis and the poor performance status.

Phase I and II pharmacokinetic and pharmacodynamic study of the proteasome inhibitor bortezomib in Japanese patients with relapsed or refractory multiple myeloma

The purpose of this phase I and II study was to evaluate the safety, pharmacokinetics, pharmacodynamics, and efficacy of bortezomib in Japanese patients with relapsed or refractory multiple myeloma. This was a dose-escalation study designed to determine the recommended dose for Japanese patients (phase I) and to investigate the antitumor activity and safety (phase II) of bortezomib administered on days 1, 4, 8, and 11 every 21 days. Thirty-four patients were enrolled. A dose-limiting toxicity was febrile neutropenia, which occurred in one of six patients in the highest-dose cohort in phase I and led to the selection of 1.3 mg/m(2) as the recommended dose. Adverse events >or= grade 3 were rare except for hematological toxicities, although there was one fatal case of interstitial lung disease. The overall response rate was 30% (95% confidence interval, 16-49%). Pharmacokinetic evaluation showed a biexponential decline, characterized by a rapid distribution followed by a longer elimination, after dose administration, whereas the area under the concentration-time curve increased proportionately with the dose. Bortezomib was effective in Japanese patients with relapsed or refractory multiple myeloma. A favorable tolerability profile was also seen, although the potential for pulmonary toxicity should be monitored closely. The pharmacokinetic and pharmacodynamic profiles of bortezomib in the present study warrant further investigations, including more relevant administration schedules.

Systemic AL amyloidosis mimicking rheumatoid arthritis

We report a patient with myeloma-associated systemic AL amyloidosis who showed chronic polyarthralgia as the main symptom. The clinical picture was similar to that of rheumatoid arthritis with regard to symmetrical swelling with tenderness in multiple joints, but inflammatory reactions were almost normal and autoantibodies were negative. He was diagnosed as having systemic AL amyloidosis based on deposition of kappa-light chain-immunoreactive amyloid in biopsied tissue and Bence Jones protein in serum and urine. Magnetic resonance imaging and bone scintigraphy suggested this disease as the cause of the polyarthralgia. Systemic AL amyloidosis may be important in the differential diagnosis of chronic polyarthralgia.

Clinically relevant end points and new drug approvals for myeloma

This manuscript summarizes the recommendations of the American Society of Hematology/US Food and Drug Administration Workshop on Clinical Endpoints in Multiple Myeloma, which brought together clinical investigators in multiple myeloma, the United States Food and Drug Administration, pharmaceutical companies, patient advocates and other concerned scientists and physicians to provide guidance, consensus and consistency in the definition of clinically relevant end points to expedite new drug approvals for multiple myeloma in the appropriate trial design settings. This manuscript will therefore be a most valuable resource to provide the framework for the design of appropriate clinical trial strategies for more rapid new drug approval in myeloma.

Antitumor activity of fludarabine against human multiple myeloma in vitro and in vivo

Fludarabine, a nucleoside analogue, plays a major role in the treatment of B-cell lymphocytic leukemia, hairy cell leukemia, and indolent lymphomas. There is a controversy about antitumor activity of fludarabine in multiple myeloma (MM). The aim of this study was to evaluate the activity of fludarabine against human myeloma cells both in vivo and in vitro. We demonstrated that myeloma cell line RPMI8226 was efficiently inhibited by fludarabine, concomitantly with decreased phosphorylation of Akt, down-regulation of the inhibitor of apoptosis proteins (IAP) family, including XIAP and survivin, and induction of apoptosis related to activation of caspase cascade. Contrary to dexamethasone, the effect of fludarabine on RPMI8226 cells was independent of interleukin-6. Fludarabine also induced cytotoxicity in dexamethasone-sensitive (MM.1S) and -resistant (MM.1R) cells at 48 h with IC50 of 13.48 microg/mL and 33.79 microg/mL, respectively. In contrast, U266 cells were resistant to fludarabine. Moreover, RPMI8226 myeloma xenograft model was established using severe combined immunodeficient mice. The tumors treated with fludarabine at 40 mg/kg increased less than 5-fold in 25 d comparing with approximately 10-fold in the control tumors, demonstrating the antitumor activity of fludarabine in vivo. These results suggest that fludarabine may be an important therapeutic option for MM patients who are resistant to dexamethasone.

Proteasome inhibitor, bortezomib, for myeloma and lymphoma

Bortezomib, a boronic acid, is a potent and selective proteasome inhibitor. The 20S proteasome is an enzyme complex present in cells, and it degrades many cell-cycle control factors, signal transduction factors, transcription factors, and oncogene and anti-oncogene products, thus controlling cell proliferation, differentiation, and apoptosis. Bortezomib is a novel molecular targeting agent which was designed to exhibit an antitumor effect by selectively inhibiting the 20S proteasome. Multiple myeloma is one of the incurable B-cell malignancies that continues to relapse with current treatment modalities, and the duration to progression becomes shorter in patients who repeatedly receive chemotherapy. There are no available treatment options in which durable efficacy can be expected after relapse; therefore, an effective therapy with a novel mechanism of action has been desired. In this review article, the results of clinical trials of bortezomib for multiple myeloma, including a Japanese phase I/II and pharmacokinetic/pharmacodynamic study, and those for non-Hodgkin lymphoma, especially for mantle cell lymphoma, are summarized. In the Japanese phase I/II study of bortezomib for relapsed multiple myeloma, this agent showed remarkable efficacy, with acceptable toxicities and unique pharmacokinetic/pharmacodynamic profiles, warranting further investigations, including more relevant administration schedules.