Relapsed multiple myeloma

Real-World Registry on the Pharmacotherapy of Multiple Myeloma and Associated Renal and Pulmonary Impairments in the Greater Gulf Region: Protocol for a Retrospective Real-World Data Study

BACKGROUND

Multiple myeloma (MM) is the second-most common cancer among hematological malignancies. Patients with active disease may experience several comorbidities, including renal insufficiency and asthma, which may lead to treatment failure. The treatment of relapsed or refractory MM (RRMM) has been associated with multiple factors, causing a decline in progression-free survival as well as overall survival with subsequent lines of therapy. Data about the characteristics of this group of patients in the Greater Gulf region are lacking.

OBJECTIVE

The primary objective of this study is to describe the disease characteristics and various treatment approaches or regimens used in the management of patients with RRMM in the Greater Gulf region.

METHODS

We will conduct a regional, retrospective study collecting real-world and epidemiological data on patients with MM in countries of the Greater Gulf region. Medical records will be used to obtain the required data. Around 150 to 170 patients' records are planned to be retrospectively reviewed over 6 months without any cross-sectional or prospective intervention. Cases will be collected from Saudi Arabia, the United Arab Emirates, Kuwait, Oman, and Qatar. Descriptive as well as analytical statistics will be performed on the extracted data. The calculated sample size will allow us to estimate the percentages of RRMM cases with acceptable precision while complying with the challenges in light of data scarcity. We will obtain a comprehensive description of the demographic profile of patients with MM; treatment outcomes; the proportion of patients with MM with renal impairment and asthma, chronic obstructive pulmonary disease, or both at the time of diagnosis and any subsequent point; and data related to treatment lines, regimens, and MM-associated morbidities.

RESULTS

Patient medical records were reviewed between June 2022 and January 2023 for eligibility and data extraction. A total of 148 patients were eligible for study inclusion, of whom 64.2% (n=95) were male and 35.8% (n=53) were female. The study is currently in its final stages of data analysis. The final manuscript is expected to be published in 2024.

CONCLUSIONS

Although MM is a predominant hematological disease, data on its prevalence and patients' characteristics in the Greater Gulf region are scarce. Therefore, this study will give us real-world insights into disease characteristics and various management approaches of patients with MM in the Greater Gulf region.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/49861.

Impact of Clonal Heterogeneity in Multiple Myeloma

Multiple myeloma is characterized by a highly heterogeneous disease distribution within the bone marrow-containing skeletal system. In this review, we introduce the molecular mechanisms underlying clonal heterogeneity and the spatio-temporal evolution of myeloma. We discuss the clinical impact of clonal heterogeneity, which is thought to be one of the biggest obstacles to overcome therapy resistance and to achieve cure.

Why real world outcome information is indispensable in making treatment decisions for multiple myeloma

OBJECTIVE

A next step in value-based healthcare (VBHC) is to use outcome information (OI) to inform patients about (personalized) outcomes of care in order to support decision-making processes. We aimed to explore multiple myeloma (MM) patients' and caregivers' views on communication of OI and (shared) decision-making (SDM).

METHODS

Focus groups with MM patients and caregivers. Main topics were experiences and needs with information provision, communication, decision-making, and use of OI. Focus groups were audiotaped, transcribed verbatim and analyzed in an iterative process by two researchers using open coding. Member checks were performed.

RESULTS

Two focus groups were held with 11 patients (91% male, M=71 years old) and 10 caregivers (89% partners). Information needs were different per moment in the disease trajectory and purpose. Patients were implicitly involved in decisions, but they were not always aware of options and no active weighing of values took place. Outcome information was mostly provided on an individual level, to monitor disease progression and initiate decisions about the need for changes in ongoing treatment regimens (follow-up treatment lines). Patients appreciated the current process of information provision and decision-making, but prefer more option awareness, a bigger role in decision-making and more OI to 1) weigh outcomes for decision-making; 2) get insight in their care trajectory; and 3) compare with other patients.

CONCLUSIONS

Participants were satisfied with information provision and decision-making, but they were only implicitly involved in decisions. Real world OI derived from VBHC improvement cycles for MM may fulfil MM patients' and caregivers' information needs and support treatment decision-making.

Carfilzomib: A Promising Proteasome Inhibitor for the Treatment of Relapsed and Refractory Multiple Myeloma

The proteasome is crucial for the degradation of intracellular proteins and plays an important role in mediating a number of cell survival and progression events by controlling the levels of key regulatory proteins such as cyclins and caspases in both normal and tumor cells. However, compared to normal cells, cancer cells are more dependent on the ubiquitin proteasome pathway (UPP) due to the accumulation of proteins in response to uncontrolled gene transcription, allowing proteasome to become a potent therapeutic target for human cancers such as multiple myeloma (MM). Up to date, three proteasome inhibitors namely bortezomib (2003), carfilzomib (2012) and ixazomib (2015) have been approved by the US Food and Drug Administration (FDA) for the treatment of patients with relapsed and/or refractory MM. This review mainly focuses on the biochemical properties, mechanism of action, toxicity profile and pivotal clinical trials related to carfilzomib, a second-generation proteasome inhibitor that binds irreversibly with proteasome to overcome the major toxicities and resistance associated with bortezomib.

Pomalidomide, cyclophosphamide, and dexamethasone for elderly patients with relapsed and refractory multiple myeloma: A study of the Korean Multiple Myeloma Working Party (KMMWP-164 study)

Patients with transplant‐ineligible relapsed and refractory multiple myeloma (RRMM) have a short life expectancy, especially when they have failed both the proteasome inhibitor and immunomodulator therapies. This study aimed to assess the efficacy and safety of pomalidomide, cyclophosphamide, and dexamethasone (PCd) in elderly patients with RRMM. This phase 2 clinical trial recruited 55 elderly patients with RRMM. The patients underwent a 28‐day treatment cycle: pomalidomide (4 mg/day on days 1‐21, administered orally) and cyclophosphamide (400 mg/day on days 1, 8, and 15; administered orally) plus dexamethasone. The median (range) age of the patients was 73.3 (64‐86) years, and 8 (14.5%) patients who were ≥ 80 years old. Eight (14.5%) and 31 (56.4%) patients exhibited stage III (revised international staging system) and frail status (simplified frailty scale), respectively. The overall response rate (ORR) and clinical benefit rate (CBR) of PCd therapy were 58.2% and 72.7%, respectively. The median PFS and median overall survival (OS) were 6.90 months (95% CI, 4.7‐9.0) and 18.48 months (95% CI, 9.4‐27.6), respectively. The incidence rate of grade ≥ 3 non‐hematological toxicities was 70.8%. In particular, the incidence rate of primary infection was 45.4%, including 21.8% for pneumonia, 9.0% for sepsis, and 14.6% for febrile neutropenia. In conclusion, PCd is an effective regimen for elderly patients with RRMM who had failed both bortezomib and lenalidomide treatments, but in whom the treatment‐associated infection is the main cause of morbidity and mortality.

Analysis of Control Arm Quality in Randomized Clinical Trials Leading to Anticancer Drug Approval by the US Food and Drug Administration

Importance

To date, an empirical evaluation of the quality of control arms in randomized clinical trials (RCTs) leading to anticancer drug approvals by the US Food and Drug Administration (FDA) has not been undertaken.

Objective

We sought to estimate the percentage of RCTs that used a control arm deemed suboptimal and led to FDA approval of anticancer drugs from January 1, 2013, to July 31, 2018.

Design, Setting, and Participants

This quality improvement study included 143 anticancer drug approvals granted by the FDA from January 1, 2013, to July 31, 2018. All approvals based on single-arm studies (48 approvals) were excluded. Approvals based on RCTs were further investigated and each trial was analyzed for design, time of patient accrual, control arm, and primary end point. Standard-of-care therapy was determined by evaluating the literature and published guidelines 1 year prior to the start of trial enrollment. The percentage of approvals based on RCTs that used suboptimal control arms was then calculated. The quality of the control arm was deemed suboptimal if the choice of control agent was restricted to exclude a recommended agent, the control arm was specified but the recommended agent was unspecified, and if prior RCT data had demonstrated that the control agent was inferior to an available alternative.

Main Outcomes and Measures

Estimated percentage of RCTs that used suboptimal control arms that led to FDA approval of anticancer agents between January 1, 2013, to July 31, 2018.

Results

A total of 145 studies that led to 143 drug approvals between January 1, 2013, and July 31, 2018, were included. Of these studies, 48 single-arm studies were excluded. The remaining 97 studies led to 95 drug approvals. Of these 95 approvals, 16 (17%) were based on RCTs with suboptimal control arms; 15 were international trials, and 1 was conducted in the United States. The type of approval was regular in 15 trials and accelerated in 1 trial. When categorized by the nature of suboptimal control, 4 (25%) trials omitted active treatment in control arm by limiting investigator's choice, 11 (63%) trials omitted active treatment in the control arm by using a control agent known to be inferior to other available agents or not allowing combinations, and 1 (13%) trial used a previously used treatment in the control arm with a known lack of benefit associated with reexposure.

Conclusions and Relevance

Although anticancer drug approvals are increasing, a proportion of these drugs are reaching the market without proven superiority to what is considered the standard of care at the time of patient enrollment in pivotal trials. The choice of control arm should be optimized to ensure that new anticancer agents being marketed are truly superior to what most clinicians would prescribe outside a clinical trial setting.

Chimeric antigen receptor T cell targeting B cell maturation antigen immunotherapy is promising for multiple myeloma

Multiple myeloma (MM) remains an incurable plasma cells malignancy because of its complex genetic heterogeneity and high relapse rate post immunotherapy. The encouraging results of chimeric antigen receptor T cell (CAR-T) targeting B cell maturation antigen (BCMA) immunotherapy clinical trials have shed light on curing MM in recent years. However, many therapeutic side effects limit the promotion and clinical use of this novel effective approach such as cytokine release syndrome, antigen escape, and neurotoxicity. We should make every effort to do further study about this immunotherapy to make it safer and effective. This review focusing on this topic clarifies the following contents: present status of MM treatment, effectiveness of CAR-T cells, features of BCMA, preclinical and clinical trials of BCMA CAR-T cells therapy, and existing problems and strategies. Hoping to provide a reference for the subsequent correlative clinical and research.

Prospective longitudinal study on quality of life in relapsed/refractory multiple myeloma patients receiving second- or third-line lenalidomide or bortezomib treatment

Treatment advances for multiple myeloma (MM) that have prolonged survival emphasise the importance of measuring patients' health-related quality of life (HRQoL) in clinical studies. HRQoL/functioning and symptoms of patients with relapsed/refractory MM (RRMM) receiving second- or third-line lenalidomide or bortezomib treatment were measured in a prospective European multicentre, observational study at different time points. At baseline, patients in the lenalidomide cohort were frailer than in the bortezomib cohort with more rapid disease progression at study entry (more patients with Eastern Cooperative Oncology Group performance status >2, shorter time from diagnosis, more chronic heart failure, higher serum creatinine levels, more patients with dialysis required). About 40% of the patients receiving lenalidomide discontinued the study in <6 months while 55% in the bortezomib cohort discontinued. No substantial HRQoL deterioration was observed for the first 6 months in patients with RRMM receiving one or the other treatment. For patients still on treatment at study completion (month 6), only the European Organization for Research and Treatment of Cancer Quality-of-Life Core domains of Diarrhoea and Global Health Status/QoL had worsened in the lenalidomide and bortezomib cohorts, respectively. A clinically meaningful deterioration in HRQoL was more often observed for patients who discontinued the study prior to 6 months in the bortezomib cohort than in the lenalidomide cohort.

Highly Expressed Integrin-α8 Induces Epithelial to Mesenchymal Transition-Like Features in Multiple Myeloma with Early Relapse

Despite recent groundbreaking advances in multiple myeloma (MM) treatment, most MM patients ultimately experience relapse, and the relapse biology is not entirely understood. To define altered gene expression in MM relapse, gene expression profiles were examined and compared among 16 MM patients grouped by 12 months progression-free survival (PFS) after autologous stem cell transplantation. To maximize the difference between prognostic groups, patients at each end of the PFS spectrum (the four with the shortest PFS and four with the longest PFS) were chosen for additional analyses. We discovered that integrin-α8 (ITGA8) is highly expressed in MM patients with early relapse. The integrin family is well known to be involved in MM progression; however, the role of integrin-α8 is largely unknown. We functionally overexpressed integrin-α8 in MM cell lines, and surprisingly, stemness features including HIF1α, VEGF, OCT4, and Nanog, as well as epithelial mesenchymal transition (EMT)-related phenotypes, including N-cadherin, Slug, Snail and CXCR4, were induced. These, consequently, enhanced migration and invasion abilities, which are crucial to MM pathogenesis. Moreover, the gain of integrin-α8 expression mediated drug resistance against melphalan and bortezomib, which are the main therapeutic agents in MM. The cBioPortal genomic database revealed that ITGA8 have significant tendency to co-occur with PDGFRA and PDGFRB and their mRNA expression were up-regulated in ITGA8 overexpressed MM cells. In summary, integrin-α8, which was up-regulated in MM of early relapse, mediates EMT-like phenotype, enhancing migration and invasion; therefore, it could serve as a potential marker of MM relapse and be a new therapeutic target.

Evaluation of low-dose thalidomide as induction and maintenance therapy in patients with multiple myeloma not eligible for stem cell transplantation

BACKGROUND

The role of thalidomide in induction and long-term maintenance therapy in patients with multiple myeloma not eligible for stem cell transplantation remains unclear. The aim of the present study was to evaluate the effect of low-dose thalidomide as induction therapy and as maintenance therapy for 24 months in patients with a complete remission after the induction chemotherapy and to monitor the survival and relapse rates.

METHODS

Between October 2005 and September 2013, 50 patients with multiple myeloma received six courses of Cyclophosphamide-Vincristine Adriamycin and Dexamethazone (c-VAD) and pamidronate, and thalidomide 100 mg daily during induction, then thalidomide 100 mg daily for 24 months as maintenance. The effects of thalidomide were assessed objectively and subjectively. Whenever necessary, electromyography and nerve capacity volume were performed monthly for 6 months, then once every 3 months until the end of treatment.

RESULTS

Primary response was 96% (CR or very good PR in 48/50 patients). Fifteen out of the remaining 48 patients relapsed during the follow-up period. Nine out of the 15 patients who relapsed showed very good partial response to treatment and four patients showed partial response. Survival rate was 81% in these patients. The primary outcome measures showed a mean and median progression-free survival of 33 and 27 months, respectively, and a mean and median overall survival of 43 and 39 months, respectively.

CONCLUSION

Low-dose thalidomide during induction therapy combined with conventional chemotherapy and a 2-year maintenance may be effective in preventing the relapse and improving the overall survival.

Clinical characteristics of patients with relapsed multiple myeloma

Although survival outcomes have improved over the last decade for patients with multiple myeloma (MM), few patients remain free of disease and most inevitably relapse. Selecting a treatment for patients with relapsed MM is challenging given the number and diversity of regimens patients may have previously received, which can affect subsequent therapeutic choices. Importantly, a number of patient- and disease-related factors can also have an effect on treatment choice, treatment efficacy, and tolerability; thus, an understanding of the heterogeneity of patients in the setting of relapsed MM is important for appropriate treatment selection. Here, we review select patient and disease characteristics reported in key interventional and observational studies in relapsed MM (including age, sex, race, and the presence of high-risk disease, renal impairment, or peripheral neuropathy at baseline) to examine common and disparate features of patients with relapsed MM. As therapeutic regimens can have varying efficacy and/or tolerability in patients depending on these factors, we also provide treatment recommendations for patients with select baseline characteristics.

Use of lenalidomide in the management of relapsed or refractory multiple myeloma: expert recommendations in Korea

Multiple myeloma (MM) is the third most common hematologic malignancy in Korea. Historically, the incidence of MM in Korea has been lower than that in Western populations, although there is growing evidence that the incidence of MM in Asian populations, including Korea, is increasing rapidly. Despite advances in the management of MM, patients will ultimately relapse or become refractory to their current treatment, and alternative therapeutic options are required in the relapsed/refractory setting. In Korea, although lenalidomide/dexamethasone is indicated for the treatment of relapsed or refractory MM (RRMM) in patients who have received at least one prior therapy, lenalidomide is reimbursable specifically only in patients with RRMM who have failed bortezomib-based treatment. Based on evidence from pivotal multinational clinical trials as well as recent studies in Asia, including Korea, lenalidomide/dexamethasone is an effective treatment option for patients with RRMM, regardless of age or disease status. Adverse events associated with lenalidomide/dexamethasone, including hematologic toxicity, venous thromboembolism, fatigue, rash, infection, and muscle cramps, are largely predictable and preventable/manageable with appropriate patient monitoring and/or the use of standard supportive medication and dose adjustment/interruption. Lenalidomide/dexamethasone provides an optimal response when used at first relapse, and treatment should be continued long term until disease progression. With appropriate modification of the lenalidomide starting dose, lenalidomide/dexamethasone is effective in patients with renal impairment and/or cytopenia. This review presents updated evidence from the published clinical literature and provides recommendations from an expert panel of Korean physicians regarding the use of lenalidomide/dexamethasone in patients with RRMM.

New approaches to management of multiple myeloma

Multiple myeloma is still an incurable disease with pattern of regression and remission followed by multiple relapses raising from the residual myeloma cells surviving even in the patients who achieve complete clinical response to treatment. New antimyeloma drugs such as thalidomide, lenalidomide, and bortezomib have dramatically changed treatment paradigm leading to both tumor reduction and tumor suppression. Much progress has been made, but still many unsolved questions remain. In the mode of sequencing treatment for patients with multiple myeloma, we are still using old drugs such as the alkylating agent melphalan, which continues to play a central role in the transplantation setting. Newer drugs are now emerging and are being tested: monoclonal antibodies, histone deacetylase (romidespsin), MLN9708 (ixazomib) a new oral proteasome inhibitor, carfilzomib, signal transduction modulator perifosine. Many advances have been made, but there is still a long way to go.

Current treatment landscape for relapsed and/or refractory multiple myeloma

Recent developments in the treatment of multiple myeloma have led to improvements in response rates and to increased survival; however, relapse is inevitable in almost all patients. Recurrence of myeloma is typically more aggressive with each relapse, leading to the development of treatment-refractory disease, which is associated with a shorter survival. Several phase II and III trials have demonstrated the efficacy of recently approved agents in the setting of relapsed and/or refractory multiple myeloma, including immunomodulatory agents, such as lenalidomide and pomalidomide, and proteasome inhibitors, such as bortezomib and carfilzomib. Currently, however, there is no standard treatment for patients with relapsed and/or refractory disease. This Review discusses the current treatment landscape for patients with relapsed and/or refractory multiple myeloma and highlights disease-related and patient-related factors--such as pre-existing comorbidities or toxicities--that are important considerations for clinicians when selecting an appropriate treatment regimen.

The glutathione synthesis inhibitor buthionine sulfoximine synergistically enhanced melphalan activity against preclinical models of multiple myeloma

Melphalan (L-PAM) has been an integral part of multiple myeloma (MM) treatment as a conditioning regimen before stem cell transplant (SCT). After initial response, most treated patients experience relapse with an aggressive phenotype. Increased glutathione (GSH) in MM may mediate resistance to L-PAM. We demonstrated that the GSH synthesis inhibitor buthionine sulfoximine (BSO) synergistically enhanced L-PAM activity (inducing 2–4 logs of cell kill) against nine MM cell lines (also in the presence of marrow stroma or cytokines) and in seven primary MM samples (combination indices <1.0). In MM cell lines, BSO significantly (P<0.05) depleted GSH, increased L-PAM-induced single-strand DNA breaks, mitochondrial depolarization, caspase cleavage and apoptosis. L-PAM depleted GSH, but GSH rapidly recovered in a L-PAM-resistant MM cell line unless also treated with BSO. Treatment with N-acetylcysteine antagonized BSO+L-PAM cytotoxicity without increasing GSH. In human MM xenografted into beige-nude-xid mice, BSO significantly depleted MM intracellular GSH and significantly increased apoptosis compared with L-PAM alone. BSO+L-PAM achieved complete responses (CRs) in three MM xenograft models including maintained CRs >100 days, and significantly increased the median event-free survival relative to L-PAM alone. Combining BSO with L-PAM warrants clinical testing in advanced MM.

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

High incidence and severity of injection site reactions in the first cycle compared with subsequent cycles of subcutaneous bortezomib

Subcutaneous (sc) administration of bortezomib (Bor) has become more common than intravenous (iv) administration in the treatment of multiple myeloma (MM), because scBor results in a lower incidence and severity of peripheral neuropathy and shows efficacy equivalent to ivBor. Bor is an irritant cytotoxic agent when it extravasates from the vasculature. Therefore, it is recommended that sc injections of Bor should be delivered on a rotating basis across eight sites on the abdomen and thighs. Previously, we reported that sc injections of Bor in the abdomen caused fewer grade 2 injection site reactions (ISRs) than those in the thigh. In the present study, we recruited more patients and expanded the scale of our analysis into ISRs following treatment with 300 scBor injections in 20 patients. ISRs of ≥grade 2 were documented in 12 of 109 (11.0 %) thigh injections, but only in three of 191 (1.6 %) abdominal injections (p < 0.001). Interestingly, ISRs of ≥grade 2 occurred more frequently in the first cycle than in the second and subsequent cycles (16.3 vs. 0.91 %, p < 0.001). These results clearly indicate that closer attention should be paid to ISR management, particularly with regard to the first cycle of scBor administration in the thigh. To our knowledge, this is the first report showing that ≥grade 2 ISRs are more common in the first cycle compared with subsequent cycles of scBor in the treatment of MM.

Bortezomib resistance can be reversed by induced expression of plasma cell maturation markers in a mouse in vitro model of multiple myeloma

Multiple myeloma (MM), the second most common hematopoietic malignancy, remains an incurable plasma cell (PC) neoplasm. While the proteasome inhibitor, bortezomib (Bz) has increased patient survival, resistance represents a major treatment obstacle as most patients ultimately relapse becoming refractory to additional Bz therapy. Current tests fail to detect emerging resistance; by the time patients acquire resistance, their prognosis is often poor. To establish immunophenotypic signatures that predict Bz sensitivity, we utilized Bz-sensitive and -resistant cell lines derived from tumors of the Bcl-X_L/Myc mouse model of PC malignancy. We identified significantly reduced expression of two markers (CD93, CD69) in “acquired” (Bz-selected) resistant cells. Using this phenotypic signature, we isolated a subpopulation of cells from a drug-naïve, Bz-sensitive culture that displayed “innate” resistance to Bz. Although these genes were identified as biomarkers, they may indicate a mechanism for Bz-resistance through the loss of PC maturation which may be induced and/or selected by Bz. Significantly, induction of PC maturation in both “acquired” and “innate” resistant cells restored Bz sensitivity suggesting a novel therapeutic approach for reversing Bz resistance in refractory MM.

Late relapse of multiple myeloma presenting as a right atrial mass

Intracardiac involvement is a rare presentation of relapsed multiple myeloma. We present a case of lobulated mass in the wall of the right atrium, with extension to the inferior vena cava and obliteration and encasement of the interatrial septum in a 57-year-old man, a known case of multiple myeloma, with progressive exertional dyspnea and anasarca.

Current and emerging treatment options for patients with relapsed myeloma

Multiple myeloma (MM) is a neoplastic disorder. It results from proliferation of clonal plasma cells in bone marrow with production of monoclonal proteins, which are detectable in serum or urine. MM is clinically characterized by destructive bone lesions, anemia, hypercalcemia and renal insufficiency. Its prognosis is severe, with a median survival after diagnosis of approximately 3 years due to frequent relapses. Treatments for patients with relapsed/refractory MM include hematopoietic cell transplantation, a rechallenge using a previous chemotherapy regimen or a trial of a new regimen. The introduction of new drugs such as thalidomide, lenalidomide and bortezomib has markedly improved MM outcomes. When relapse occurs, the clinician's challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. Patients with indolent relapse can be first treated with a 2-drug or a 3-drug combination. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Autologous stem cell transplantation should be considered as salvage therapy at first relapse for patients who have cryopreserved stem cells early in the disease course. The aim of this review is to provide an overview on the pharmacological and molecular action of treatments used for patients with relapsed/refractory multiple myeloma.

United Kingdom Myeloma Forum (UKMF) position statement on the use of bendamustine in myeloma

Bendamustine is a unique bifunctional alkylating agent with promising activity in myeloma. Despite the increasing number of studies demonstrating its efficacy in both the upfront and relapse settings, including patients with renal insufficiency, the optimal use of bendamustine, in terms of dosage, schedule and combination with other agents, has yet to be defined. It is currently licensed for use as frontline treatment with prednisolone for patients with myeloma who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib. Studies in relapsed/refractory patients are currently ongoing with other combinations. Given the increasing data to date, the UK Myeloma Forum believes that bendamustine with steroids alone or in combination with a novel agent could be considered for patients with multiply relapsed myeloma. This document provides guidance for the use of bendamustine for patients with myeloma until the results of definitive studies are available.

Carfilzomib: in relapsed, or relapsed and refractory, multiple myeloma

Intravenous carfilzomib is a peptide epoxyketone, next-generation proteasome inhibitor, which has been granted accelerated approval in the US for the treatment of patients with multiple myeloma who have received at least two prior therapies, including bortezomib and an immunomodulatory agent (thalidomide or lenalidomide), and have demonstrated disease progression on or within 60 days of completion of the last therapy. Carfilzomib displays high selectivity for and irreversibly inhibits the chymotrypsin-like catalytic activity of the 20S proteasome core particle, which results in cell growth arrest and apoptosis. In the pivotal, phase II, noncomparative trial in heavily pre-treated patients (n = 266) with relapsed and refractory multiple myeloma, intravenous carfilzomib administered in 28-day cycles for up to 12 cycles produced an overall response rate of 23.7% in the response-evaluable population. The median duration of response was 7.8 months, the median progression-free survival was 3.7 months and the median overall survival was 15.6 months. Carfilzomib had an acceptable tolerability profile in patients with relapsed, or relapsed and refractory, multiple myeloma. There was a low incidence of grade 3 or higher peripheral neuropathy.

Good clinical activity and favorable toxicity profile of once weekly bortezomib, fotemustine, and dexamethasone (B-MuD) for the treatment of relapsed multiple myeloma

Since multiple myeloma (MM) is still not-curable, the management of relapse remains challenging. Given the known efficacy of alkylating agents in MM, we conducted a phase I/II study to test a new three drug combination in which Fotemustine (Muphoran), an alkylating agent of nitrosurea family, was added to bortezomib + dexamethasone backbone (B-MuD) for the treatment of MM relapsed patients. Fotemustine was administered at two dose levels (80–100 mg/m² i.v.) on day 1. The original 21-day schedule was early amended for extra-hematological toxicity and a 35-day schedule was adopted (Bortezomib 1.3 mg/m² i.v. on days 1, 8, 15, and 22, Dexamethasone 20 mg i.v. on days 1, 8, 15, and 22) for a total of six courses. Twenty-four patients were enrolled. The maximum tolerated dose of Fotemustine was 100 mg/m². The overall response rate was of 62% (CR 8%, VGPR 33%, and PR 21%). The median OS was 28.5 months, the median progression-free survival (PFS) was 19.1 months. B-MuD resulted effective in patients previous exposed to bortezomib without difference of response (P = 0.25) and PFS (P = 0.87) when compared to bortezomib-naive patients. Thrombocytopenia was the most common AE overall. In conclusion, B-MuD is an effective and well tolerated combination in relapsed MM patients even in advanced disease phase. © Am. J. Hematol., 88:102–106, 2013. © 2012 Wiley Periodicals, Inc.

A prospective, international phase 2 study of bortezomib retreatment in patients with relapsed multiple myeloma

Multiple myeloma (MM) typically follows a relapsing course with many patients requiring multiple therapies. This single-arm phase 2 study prospectively evaluated the efficacy and safety of bortezomib retreatment in MM patients who had relapsed after achieving at least a partial response (≥ PR) to prior bortezomib-based therapy. Patients aged ≥ 18 years, with measurable, secretory MM, who relapsed ≥ 6 months after prior bortezomib treatment were eligible. Patients received up to eight cycles of bortezomib (± dexamethasone). The primary endpoint was best confirmed response at retreatment; secondary endpoints included duration of response (DOR), time to progression (TTP), and safety. Adverse events (AEs) were graded by National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. A total of 130 patients (median of two prior lines of therapy) were enrolled and received retreatment. At retreatment, 28% and 72% of patients received bortezomib and bortezomib-dexamethasone, respectively. Overall response rate was 40%. In patients who achieved ≥ PR, median DOR and TTP were 6.5 and 8.4 months, respectively. Thrombocytopenia was the most common grade ≥ 3 AE (35%). Forty percent of patients experienced neuropathy events, which improved and resolved in a median of 1.5 and 8.9 months, respectively. In conclusion, bortezomib retreatment was effective and tolerable in relapsed MM patients, with no evidence of cumulative toxicities.

Results of a phase 2 trial of the single-agent histone deacetylase inhibitor panobinostat in patients with relapsed/refractory Waldenström macroglobulinemia

The present study aimed to determine the safety and activity of the histone deacetylase inhibitor panobinostat in patients with relapsed/refractory Waldenström macroglobulinemia (WM). Eligibility criteria included patients with relapsed/refractory WM with any number of prior therapies. Patients received panobinostat at 30 mg 3 times a week; 12 of 36 (33%) patients were enrolled at 25 mg dose. A total of 36 patients received therapy. The median age was 62 years (range, 47-80) and the median number of prior therapies was 3 (range, 1-8). All of the patients had received prior rituximab. Minimal response (MR) or better was achieved in 47% of patients (90% confidence interval [CI], 33-62), with 22% partial remissions and 25% MR. In addition, 18 (50%) patients achieved stable disease and none showed progression while on therapy. The median time to first response was 1.8 months (range, 1.7-3.2). The median progression-free survival was 6.6 months(90% CI, 5.5-14.8). Grade 3 and 4 toxicities included thrombocytopenia (67%), neutropenia (36%), anemia (28%), leukopenia (22%), and fatigue (11%). We conclude that panobinostat is an active therapeutic agent in patients with relapsed/ refractory WM. This study (www.clinicaltrials.gov identifier: NCT00936611) establishes a role for histone deacetylase inhibitors as an active class of therapeutic agents in WM.

European perspective on multiple myeloma treatment strategies: update following recent congresses

The management of multiple myeloma has undergone profound changes over the recent past as a result of advances in our understanding of the disease biology as well as improvements in treatment and supportive care strategies. Notably, recent years have seen a surge in studies incorporating the novel agents thalidomide, bortezomib, and lenalidomide into treatment for different disease stages and across different patient groups. This article presents an update to a previous review of European treatment practices and is based on discussions during an expert meeting that was convened to review novel agent data published or presented at medical meetings until the end of 2011 and to assess their impact on treatment strategies.

Treatment strategies in relapsed and refractory multiple myeloma: a focus on drug sequencing and 'retreatment' approaches in the era of novel agents

Treatment of multiple myeloma has evolved over the last decade, most notably with the introduction of highly effective novel agents. It is now possible to aim for deep disease responses in a greater number of patients in an attempt to prolong remission duration and survival. Initially introduced in the relapsed setting, the novel agents, namely thalidomide, bortezomib and lenalidomide, are now being increasingly incorporated into upfront treatment strategies, raising questions about the feasibility of 'retreatment' with such agents. Also, in a disease that is characterized by multiple relapses, the 'sequencing' of the different effective options is an important question. In the frontline setting, the first remission is likely to be the period during which patients will enjoy the best quality of life. Thus, the goal should be to achieve a first remission that is the longest possible by using the most effective treatment upfront. At relapse, the challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. The decision will depend on both disease- and patient-related factors. This review aimed to assess the available research data addressing 'retreatment' approaches, drug 'sequencing' and the long-term impact of upfront therapy with novel drugs.

The role of maintenance thalidomide therapy in multiple myeloma: MRC Myeloma IX results and meta-analysis

Thalidomide maintenance has the potential to modulate residual multiple myeloma (MM) after an initial response. This trial compared the effect of thalidomide maintenance and no maintenance on progression-free survival (PFS) and overall survival (OS) in MM patients. After intensive or nonintensive induction therapy, 820 newly diagnosed MM patients were randomized to open-label thalidomide maintenance until progression, or no maintenance. Interphase FISH (iFISH) analysis was performed at study entry. Median PFS was significantly longer with thalidomide maintenance (log-rank P < .001). Median OS was similar between regimens (log-rank P = .40). Patients with favorable iFISH showed improved PFS (P = .004) and a trend toward a late survival benefit. Patients with adverse iFISH receiving thalidomide showed no significant PFS benefit and worse OS (P = .009). Effective relapse therapy enhanced survival after progression, translating into a significant OS benefit. Meta-analysis of this and other studies show a significant late OS benefit (P < .001, 7-year difference hazard ratio = 12.3; 95% confidence interval, 5.5-19.0). Thalidomide maintenance significantly improves PFS and can be associated with improved OS. iFISH testing is important in assessing the clinical impact of maintenance therapy. Overview analysis demonstrated that thalidomide maintenance was associated with a significant late OS benefit. This trial was registered at www.isrctn.org as #ISRCTN68454111.