Treatment of relapsed and refractory multiple myeloma

Patient-reported outcomes in relapsed/refractory multiple myeloma: a systematic review

PURPOSE

We performed a systematic review to quantify the amount of evidence-based data available on patient-reported outcomes (PRO) in Relapsed/Refractory Multiple Myeloma (RRMM) patients and to examine the added value of such studies in supporting clinical decision-making.

METHODS

We conducted a search in PubMed/Medline and the Cochrane Library to identify studies published between January 1990 and May 2017. All studies, regardless of the design, including patients with RRMM and also evaluating PRO were considered. For each study, we collected both PRO and traditional clinical outcomes, such as survival and toxicity information, based on a predefined data extraction form.

RESULTS

After having screened 1680 records, 11 studies were identified and these included six randomized controlled trials (RCT). Overall, there were five studies focusing on proteasome inhibitors (PIs), four on immunomodulatory drugs (IMiDs), one on both PIs and IMiDs, and one on monoclonal antibodies. Considering only RCTs, it was found that primary clinical efficacy endpoints frequently favored experimental arms, while (physician-reported) toxicity data did not. However, inspection of PRO data revealed novel information that often contrasted with standard toxicity, for example, by not indicating worse quality of life outcomes or symptom severity for patients enrolled in the experimental arms.

CONCLUSIONS

There is paucity of evidence-based data regarding the impact of therapies on quality of life and symptom burden of patients with RRMM. Inclusion of PRO in future studies of patients with RRMM is needed to better inform clinical decision-making.

PD1 blockade enhances cytotoxicity of in vitro expanded natural killer cells towards myeloma cells

Aiming for an adoptive natural killer (NK) cell therapy, we have developed a novel protocol to expand NK cells from peripheral blood. With this protocol using anti-human CD16 antibody and interleukin (IL)-2, NK (CD3-CD56+) cells could be expanded about 4000-fold with over 70% purity during a 21-day culture. The expanded NK (exNK) cells were shown to be highly cytotoxic to multiple myeloma (MM) cells (RPMI8226) at low NK-target cell ratios. Furthermore, NK cells expanded in the presence of a blocking antibody (exNK+PD1-blockage) against programmed cell death protein-1 (PD1), a key counteracting molecule for NK and T cell activity, demonstrated more potent cytolytic activity against the RPMI8226 than the exNK cells without PD1 blocking. In parallel, the exNK cells showed significantly higher expression of NK activation receptors NKG2D, NKp44 and NKp30. In a murine model of MM, transfusion of exNK cells, exNK+PD1-blockage, and exNK plus intratumor injection of anti-PD-L2 antibody (exNK+PD-L2 blockage) all significantly suppressed tumor growth and prolonged survival of the myeloma mice. Importantly, exNK+PD1-blockage presented more efficient therapeutic effects. Our results suggest that the NK cell expansion protocol with PD1 blockade presented in this study has considerable potential for the clinical application of allo- and auto-NK cell-based therapies against malignancies.

Characteristics and outcomes of patients with multiple myeloma : Data from a developing country

Background: Multiple myeloma (MM) is a plasma cell disorder characterized by presence of monoclonal protein in serum or urine or both, increased bone marrow plasma cells, osteolytic lesion, hypercalcemia, and anemia. Several combination regimens are commonly recommended for treatment of multiple myeloma. The present study aimed at determining the characteristics and outcomes of patients with multiple myeloma treated at our centre. Methods: During July 2012 and December 2015, all patients with proven diagnosis of MM were included in this study. Data were collected from hospital information system. The characteristics and outcomes of all patients were analyzed. Progression- free survival and overall survival of patients were also estimated. Kaplan-Meier curves and Log-rank test were applied and SPSS Version19 was used for data analysis. Results: A total of 82 patients, with the median age of 51 years (Range: 23-64 yrs.) were available for final analysis. The number of patients with IgG and IgA type was 48 (58.5%) and 15(18.3%), respectively. There were 7 (8.5%) patients with non-secretory type. Most of the patients (n= 59; 71.9%) were treated with CTD regimen and 13 (15.8%) received bortezomib-based treatment. The median progression-free survival time was 30 months, and overall survival time was 48 months. The cumulative probability of survival at 36 months was 85%. Conclusion: Based on our results, the onset of multiple myeloma occurs in relatively younger age groups. A small number of patients received bortezomib due to cost issues. PFS and OS in our study were comparable with published literature.

Management of relapsed and refractory multiple myeloma: novel agents, antibodies, immunotherapies and beyond

Despite enormous advances, management of multiple myeloma (MM) remains challenging. Multiple factors impact the decision to treat or which regimen to use at MM relapse/progression. Recent major randomized controlled trials (RCTs) showed widely varying progression-free survivals (PFS), ranging from a median of 4 months (MM-003) to 23.6 months (ASPIRE). Based on these RCTs, next-generation proteasome inhibitors (carfilzomib and ixazomib), next-generation immunomodulatory agent (pomalidomide), and monoclonal antibodies (elotuzumab and daratumumab) were approved for relapsed and refractory MM. Daratumumab, targeting CD38, has multiple mechanisms of action including modulation of the immunosuppressive bone marrow micro-environment. In addition to the remarkable single agent activity in refractory MM, daratumumab produced deep responses and superior PFS in MM when combined with lenalidomide/dexamethasone, or bortezomib/dexamethasone. Other anti-CD38 antibodies, such as isatuximab and MOR202, are undergoing assessment. Elotuzumab, targeting SLAMF7, yielded superior response rates and PFS when combined with lenalidomide/dexamethasone. New combinations of these next generation novel agents and/or antibodies are undergoing clinical trials. Venetoclax, an oral BH3 mimetic inhibiting BCL2, showed single agent activity in MM with t(11;14), and is being studied in combination with bortezomib/dexamethasone. Selinexor, an Exportin-1 inhibitor, yielded promising results in quad- or penta-refractory MM including patients resistant to daratumumab. Pembrolizumab, an anti-PD1 check-point inhibitor, is being tested in combination with lenalidomide/dexamethasone or pomalidomide/dexamethasone. Chimeric antigen receptor-T cells targeting B-cell maturation antigen have yielded deep responses in RRMM. Finally, salvage autologous stem cell transplantation (ASCT) remains an important treatment in MM relapsing/progressing after a first ASCT. Herein, the clinical trial data of these agents are summarized, cautious interpretation of RCTs highlighted, and algorithm for salvage treatment of relapse/refractory MM proposed.

Current and New Therapeutic Strategies for Relapsed and Refractory Multiple Myeloma: An Update

Although survival of multiple myeloma patients has at least doubled during recent years, most patients eventually relapse, and treatment at this stage may be particularly complex. At the time of relapse, the use of alternative drugs to those given upfront is current practice. However, many new options are currently available for the treatment of relapsed multiple myeloma, including recently approved drugs, such as the second- and third-generation proteasome inhibitors carfilzomib and ixazomib, the immunomodulatory agent pomalidomide, the monoclonal antibodies daratumumab and elotuzumab and the histone deacetylase inhibitor panobinostat, but also new targeted agents are under active investigation (e.g. signal transduction modulators, kinesin spindle protein inhibitors, and inhibitors of NF-kB, MAPK, AKT). We here describe a new paradigm for the treatment of relapsed multiple myeloma. The final goal should be finding a balance among efficacy, toxicity, and cost and, at the end of the road, achieving long-lasting control of the disease and eventually even cure in a subset of patients.

Targeting the ubiquitin-proteasome system for cancer treatment: discovering novel inhibitors from nature and drug repurposing

In the past 15 years, the proteasome has been validated as an anti-cancer drug target and 20S proteasome inhibitors (such as bortezomib and carfilzomib) have been approved by the FDA for the treatment of multiple myeloma and some other liquid tumors. However, there are shortcomings of clinical proteasome inhibitors, including severe toxicity, drug resistance, and no effect in solid tumors. At the same time, extensive research has been conducted in the areas of natural compounds and old drug repositioning towards the goal of discovering effective, economical, low toxicity proteasome-inhibitory anti-cancer drugs. A variety of dietary polyphenols, medicinal molecules, metallic complexes, and metal-binding compounds have been found to be able to selectively inhibit tumor cellular proteasomes and induce apoptotic cell death in vitro and in vivo, supporting the clinical success of specific 20S proteasome inhibitors bortezomib and carfilzomib. Therefore, the discovery of natural proteasome inhibitors and researching old drugs with proteasome-inhibitory properties may provide an alternative strategy for improving the current status of cancer treatment and even prevention.

Efficacy of daratumumab-based therapies in patients with relapsed, refractory multiple myeloma treated outside of clinical trials

Outside of clinical trials, experience with daratumumab-based combination therapies (DCTs) using bortezomib (V)/lenalidomide (R)/pomalidomide (P), and dexamethasone (d) in relapsed/refractory multiple myeloma (RRMM) is limited. We reviewed the outcomes of 126 patients who received ≥ 1 cycle of any DCT. Median age at DCT initiation was 67 (range, 43-93) years. High-risk cytogenetics was present in 33% patients. Median number of prior therapies was 4 (range, 1-14) and time to first DCT from diagnosis was 4.3 years (range, 0.4-13.0). Seventeen (13%) patients were refractory to single agent daratumumab. Fifty-two (41%), 34 (27%), 23 (18%), and 17 (14%) received DPd, DRd, DVd and "other" DCTs, respectively. Overall response rate was 47%. Median follow-up was 5.5 months (95% CI, 4.2-6.1). Median progression-free survival (PFS) was 5.5 months (95% CI, 4.2-7.8). Median overall survival was not reached (NR) with any regimen. Median PFS (months) was worst for penta-refractory MM (n = 8) vs quadruple refractory MM (n = 18) and others (n = 100) (2.2 [95% CI, 1-2.4] vs 3.1 [95% CI, 2.1-NR] vs 5.9 [95% CI, 5.0-NR]; P < .001); those who were refractory to ≥1 agents used in the DCT vs others (4.9 [95% CI, 3.1-6.0] vs 8.2 [95% CI, 4.6-NR]; P = .02); and those who received >2 prior therapies vs others (5.0 months [95% CI, 3.7-5.9] vs NR [95% CI, NR-NR]; P = .002). Non-hematologic toxicities included infections (38%), fatigue (32%), and infusion reactions (18%). Grade 3 or higher hematological toxicities were seen in 41% of patients. DCTs are effective in RRMM. ORR and PFS in heavily pretreated patients are lower than those reported in clinical trials.

A compound chimeric antigen receptor strategy for targeting multiple myeloma

Current clinical outcomes using chimeric-antigen receptors (CARs) against multiple myeloma show promise in the eradication of bulk disease. However, these anti-BCMA (CD269) CARs observe relapse as a common phenomenon after treatment due to the reemergence of either antigen-positive or -negative cells. Hence, the development of improvements in CAR design to target antigen loss and increase effector cell persistency represents a critical need. Here, we report on the anti-tumor activity of a CAR T-cell possessing two complete and independent CAR receptors against the multiple myeloma antigens BCMA and CS1. We determined that the resulting compound CAR (cCAR) T-cell possesses consistent, potent and directed cytotoxicity against each target antigen population. Using multiple mouse models of myeloma and mixed cell populations, we are further able to show superior in vivo survival by directed cytotoxicity against multiple populations compared to a single-expressing CAR T-cell. These findings indicate that compound targeting of BCMA and CS1 on myeloma cells can potentially be an effective strategy for augmenting the response against myeloma bulk disease and for initiation of broader coverage CAR therapy.

Effect of pomalidomide on relapsed/refractory multiple myeloma: a systematic review and meta-analysis

In this work, we aim to further analyze the effect of pomalidomide for relapsed and/or refractory multiple myeloma (RRMM). A systematic literature search of PubMed, MEDLINE and EMBASE was conducted on September 20, 2016. Pooled effect size (ES) with corresponding 95% confidence intervals (CIs) were calculated using random-effects model. STATA software (version 12.0; Stata Corporation; College Station, TX, USA) was employed to do all statistical analyses. A total of 8 studies were included for analysis. The combined results demonstrated that the pooled proportion of overall response rate (ORR) was 0.35 (95% CI 0.27 to 0.43, P=0.000), and the pooled proportion of complete response rate (CRR) was 0.02 (95% CI 0.01 to 0.03, P=0.541). Pomalidomide was generally well tolerated by patients reported in the studies. Further studies would be required to conduct more prospective randomized controlled trials (RCTs) with larger samples to assess the proper place of pomalidomide as single agent or combined with other agents for RRMM.

The BET bromodomain inhibitor CPI203 improves lenalidomide and dexamethasone activity in in vitro and in vivo models of multiple myeloma by blockade of Ikaros and MYC signaling

Most patients with multiple myeloma treated with current therapies, including immunomodulatory drugs, eventually develop relapsed/refractory disease. Clinical activity of lenalidomide relies on degradation of Ikaros and the consequent reduction in IRF4 expression, both required for myeloma cell survival and involved in the regulation of MYC transcription. Thus, we sought to determine the combinational effect of an MYC-interfering therapy with lenalidomide/dexamethasone. We analyzed the potential therapeutic effect of the combination of the BET bromodomain inhibitor CPI203 with the lenalidomide/dexamethasone regimen in myeloma cell lines. CPI203 exerted a dose-dependent cell growth inhibition in cell lines, indeed in lenalidomide/dexamethasone-resistant cells (median response at 0.5 μM: 65.4%), characterized by G1 cell cycle blockade and a concomitant inhibition of MYC and Ikaros signaling. These effects were potentiated by the addition of lenalidomide/dexamethasone. Results were validated in primary plasma cells from patients with multiple myeloma co-cultured with the mesenchymal stromal cell line stromaNKtert. Consistently, the drug combination evoked a 50% reduction in cell proliferation and correlated with basal Ikaros mRNA expression levels (P=0.04). Finally, in a SCID mouse xenotransplant model of myeloma, addition of CPI203 to lenalidomide/dexamethasone decreased tumor burden, evidenced by a lower glucose uptake and increase in the growth arrest marker GADD45B, with simultaneous downregulation of key transcription factors such as MYC, Ikaros and IRF4. Taken together, our data show that the combination of a BET bromodomain inhibitor with a lenalidomide-based regimen may represent a therapeutic approach to improve the response in relapsed/refractory patients with multiple myeloma, even in cases with suboptimal prior response to immunomodulatory drugs.

Impact of prior therapy on the efficacy and safety of oral ixazomib-lenalidomide-dexamethasone vs. placebo-lenalidomide-dexamethasone in patients with relapsed/refractory multiple myeloma in TOURMALINE-MM1

Prior treatment exposure in patients with relapsed/refractory multiple myeloma may affect outcomes with subsequent therapies. We analyzed efficacy and safety according to prior treatment in the phase 3 TOURMALINE-MM1 study of ixazomib-lenalidomide-dexamethasone (ixazomib-Rd) versus placebo-Rd. Patients with relapsed/refractory multiple myeloma received ixazomib-Rd or placebo-Rd. Efficacy and safety were evaluated in subgroups defined according to type (proteasome inhibitor [PI] and immunomodulatory drug) and number (1 vs. 2 or 3) of prior therapies received. Of 722 patients, 503 (70%) had received a prior PI, and 397 (55%) prior lenalidomide/thalidomide; 425 patients had received 1 prior therapy, and 297 received 2 or 3 prior therapies. At a median follow up of ~15 months, PFS was prolonged with ixazomib-Rd vs. placebo-Rd regardless of type of prior therapy received; HR 0.739 and 0.749 in PI-exposed and –naïve patients, HR 0.744 and 0.700 in immunomodulatory-drug-exposed and -naïve patients, respectively. PFS benefit with ixazomib-Rd vs. placebo-Rd appeared greater in patients with 2 or 3 prior therapies (HR 0.58) and in those with 1 prior therapy without prior transplant (HR 0.60) versus those with 1 prior therapy and transplant (HR 1.23). Across all subgroups, toxicity was consistent with that seen in the intent-to-treat population. In patients with relapsed/refractory multiple myeloma, ixazomib-Rd was associated with a consistent clinical benefit vs. placebo-Rd regardless of prior treatment with bortezomib or immunomodulatory drugs. Patients with 2 or 3 prior therapies, or 1 prior therapy without transplant seemed to have greater benefit than patients with 1 prior therapy and transplant. TOURMALINE-MM1 registered at clinicaltrials.gov identifier: 01564537.

How I treat first relapse of myeloma

The standard treatment of relapsed multiple myeloma has been either lenalidomide-dexamethasone (RD) or bortezomib-dexamethasone (VD) but it is changing rapidly for 2 reasons. First, lenalidomide and bortezomib are currently used in frontline treatment and many patients become resistant to these agents early in the course of their disease. Second, 6 second-line new agents have been recently developed and offer new possibilities (pomalidomide, carfilzomib and ixazomib, panobinostat, elotuzumab, and daratumumab). Recent randomized studies have shown that triple combinations adding 1 of these new agents (except pomalidomide) to the RD or VD regimens were superior to the double combinations in terms of response rate and progression-free survival (PFS). Their place in the treatment of first relapse is discussed here. Among these agents, daratumumab is clearly a breakthrough and daratumumab-based combinations might become the preferred option in the near future. However, all of these drugs are expensive and are not available or affordable in all countries. We propose a decision algorithm for first relapse in fit patients with the objective of achieving the best PFS. The choice of salvage regimen is based on lenalidomide/bortezomib resistance, daratumumab availability, and cost. Autologous transplantation should be considered in younger patients if not used upfront.

[Pomalidomide for multiple myeloma]

Pomalidomide is a second-generation immunomodulatory drug (IMID). Its efficiency overtakes its predecessors' (thalidomide, lenalidomide), with less toxicity. It is indicated in the treatment of refractory or relapsed multiple myeloma, associated to dexamethasone. It is available in France since 2013, following the results of different studies.

Global methylation and promoter-specific methylation of the P16, SOCS-1, E-cadherin, P73 and SHP-1 genes and their expression in patients with multiple myeloma during active disease and remission

Tumor suppressor gene promoter CpG island methylation is a well-recognized mechanism in cancer pathogenesis, but its role in multiple myeloma (MM) is controversial. The present study investigated the methylation status and expression of P16, suppressor of cytokine signaling 1 (SOCS-1), P73, E-cadherin and Src homology region 2 domain-containing phosphatase 1 (SHP-1), as well as global methylation in patients with MM during active disease and remission. Bone marrow samples were obtained from 43 patients at the Multiple Myeloma Clinic, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (Mexico City, Mexico) during active disease and remission. Methylation-specific polymerase chain reaction and ELISA were performed on bisulfite-treated or untreated DNA to determine promoter-specific or genomic methylation, respectively. Gene expression was measured using reverse-transcription polymerase chain reaction. The results indicated that SOCS-1 methylation occurred more frequently during active disease than remission [29 vs. 3.2% (P=0.021)] and was associated with more advanced forms of the disease [international staging system (ISS) 3, 16.67% vs. ISS 1, 8.3% (P=0.037)]. SHP-1 methylation during active disease was associated with a lower probability of survival at 39-month follow up (median), 52.5 vs. 87.5% (P=0.025). The percentage of methylation was associated with active disease at remission, but this was not significant. Global hypomethylation at remission was a negative predictor factor for overall survival (OS). The results indicated that methylated P16, SOCS-1 and SHP-1 were associated with clinical variables of poor prognosis in MM, likewise the persistence of global hypomethylation at remission. The negative impact on OS of global hypomethylation at remission must be confirmed in a larger sample. Future studies are necessary to investigate whether patients with global hypermethylation at remission should receive more aggressive treatments to improve their OS.

High-risk multiple myeloma: a multifaceted entity, multiple therapeutic challenges

The term high-risk multiple myeloma is aimed to identify a heterogeneous group of patients who are more likely to progress and die early of their disease. Therefore, recognition of these patients is crucial. With the increase in the number of treatment options, the outcome for high-risk patients has probably improved, although the true extent of this improvement remains unknown, due to both the heterogeneous components of high-risk disease and its under-representation in clinical trials. In this article, we review the definitions of high-risk disease, emphasizing the fact that no single definition can represent the entire high-risk population. In the second part, we review the treatment options available for the management of high-risk myeloma as well as our general approach for high-risk disease. In light of the poor prognosis associated with high-risk myeloma, even in the current era, new approaches for the management of this subset of patients are needed.

The role of SLAMF7 in multiple myeloma: impact on therapy

INTRODUCTION

Multiple myeloma (MM), a mature B-cell neoplasm, is the second most common hematologic malignancy worldwide. Despite significant improvements in outcome with new therapies, the majority of responding patients will eventually develop resistance to treatment. Furthermore, patients swith disease refractory to both proteasome inhibitors and immunomodulatory drugs (IMiDs) have a poor prognosis. Areas covered: Several new therapeutic approaches are emerging and immunotherapeutic strategies present an important advance for the treatment of patients with relapsed or refractory MM. Among the monoclonal antibodies under development in MM, those targeting SLAMF7 and CD38 have shown the most consistent benefit in trials to date. In this review, we will specifically focus on elotuzumab (anti-SLAMF7 antibody), and provide a summary of the mechanism of action, the clinical results and the safety profile of this new drug. Expert commentary: Although elotuzumab has no single agent activity in MM, randomized trials in relapsed/refractory MM have demonstrated significantly improved progression-free survival when the agent is added to bortezomib-dexamethasone or lenalidomide-dexamethasone. Furthermore, this agent with its novel mechanism of action can be combined with standard therapies without a significant increase in toxicity. Elotuzumab is a highly effective therapy and future data are necessary to identify the best place for this therapy in the setting of MM.