Treatment of relapsed and refractory multiple myeloma

Idecabtagene Vicleucel in Relapsed and Refractory Multiple Myeloma

BACKGROUND

Idecabtagene vicleucel (ide-cel, also called bb2121), a B-cell maturation antigen-directed chimeric antigen receptor (CAR) T-cell therapy, has shown clinical activity with expected CAR T-cell toxic effects in patients with relapsed and refractory multiple myeloma.

METHODS

In this phase 2 study, we sought to confirm the efficacy and safety of ide-cel in patients with relapsed and refractory myeloma. Patients with disease after at least three previous regimens including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 antibody were enrolled. Patients received ide-cel target doses of 150 × 10⁶ to 450 × 10⁶ CAR-positive (CAR+) T cells. The primary end point was an overall response (partial response or better); a key secondary end point was a complete response or better (comprising complete and stringent complete responses).

RESULTS

Of 140 patients enrolled, 128 received ide-cel. At a median follow-up of 13.3 months, 94 of 128 patients (73%) had a response, and 42 of 128 (33%) had a complete response or better. Minimal residual disease (MRD)-negative status (<10^-5 nucleated cells) was confirmed in 33 patients, representing 26% of all 128 patients who were treated and 79% of the 42 patients who had a complete response or better. The median progression-free survival was 8.8 months (95% confidence interval, 5.6 to 11.6). Common toxic effects among the 128 treated patients included neutropenia in 117 patients (91%), anemia in 89 (70%), and thrombocytopenia in 81 (63%). Cytokine release syndrome was reported in 107 patients (84%), including 7 (5%) who had events of grade 3 or higher. Neurotoxic effects developed in 23 patients (18%) and were of grade 3 in 4 patients (3%); no neurotoxic effects higher than grade 3 occurred. Cellular kinetic analysis confirmed CAR+ T cells in 29 of 49 patients (59%) at 6 months and 4 of 11 patients (36%) at 12 months after infusion.

CONCLUSIONS

Ide-cel induced responses in a majority of heavily pretreated patients with refractory and relapsed myeloma; MRD-negative status was achieved in 26% of treated patients. Almost all patients had grade 3 or 4 toxic effects, most commonly hematologic toxic effects and cytokine release syndrome. (Funded by bluebird bio and Celgene, a Bristol-Myers Squibb company; KarMMa ClinicalTrials.gov number, NCT03361748.).

Association of Morbid Progression With Overall Survival Among Patients With Multiple Myeloma: Validation of the Progression-free Survival Endpoint

INTRODUCTION

Multiple myeloma (MM) is an incurable malignancy, marked by end-organ damage that is frequently irreversible. Progressive disease (PD) can be defined as morbid PD, associated with new-onset hypercalcemia, renal insufficiency, anemia, or lytic bone lesions (CRAB symptoms), or as asymptomatic biochemical progression. The frequency of morbid versus asymptomatic PD and its effect on survival is unknown. Our aim was to determine the incidence of morbid PD, and to evaluate if this influences survival.

PATIENTS AND METHODS

Data from 2 phase III trials of transplant-ineligible patients with newly diagnosed MM were included in a post hoc analysis.

RESULTS

Of 2082 patients enrolled, 1243 (59.7%) experienced PD. At first progression, 543 (43.7%) patients had morbid PD; 12 (2.2%) had hypercalcemia, 271 (49.9%) had renal insufficiency, 370 (68.1%) developed anemia, and 79 (14.5%) developed new or enlarged bone lesions. A total of 700 (56.3%) patients had asymptomatic PD. Patients with morbid PD had worse second progression-free survival (PFS) versus patients with asymptomatic biochemical PD (median second PFS, 11.5 months vs. 20.0 months; hazard ratio, 1.63; 95% confidence interval, 1.43-1.85; P < .0001) and worse overall survival (OS) (median OS, 23.2 months vs 39.3 months; hazard ratio, 1.51; 95% confidence interval, 1.30, 1.74; P < .0001).

CONCLUSIONS

Morbid PD occurs frequently and is associated with inferior second PFS and OS. As CRAB symptoms may not reverse with therapy, morbid PD is a meaningful event, and its association with a shortened PFS adds validity to PFS as a relevant endpoint in patients with MM.

Blocking the short isoform of augmenter of liver regeneration inhibits proliferation of human multiple myeloma U266 cells via the MAPK/STAT3/cell cycle signaling pathway

Multiple myeloma (MM) is the second most common haematological malignancy and remains an incurable disease, with most patients relapsing and requiring further treatment. Augmenter of liver regeneration (ALR) is a vital protein affecting fundamental processes such as energy transduction, cell survival and regeneration. Silencing ALR inhibits cell proliferation and triggers apoptosis in human MM U266 cells. However, little is known about the role of 15-kDa-ALR on MM. In the present study, the role of 15-kDa-ALR in human MM cells was investigated. Blocking extracellular 15-kDa-ALR with an anti-ALR monoclonal antibody (McAb) decreased the proliferation and viability of U266 cells. However, the results of flow cytometry revealed no changes in apoptosis, and the expression levels of Bax, Bcl-2, caspase-3 and cleaved caspase-3 were not affected. However, combined treatment with anti-ALR McAb and epirubicin increased the apoptosis of U266 cells. RNA sequencing results indicated that the ERK1/2, JNK-MAPK and STAT3 signaling pathways, as well as the cell cycle, were associated with the mechanism of action of the anti-ALR McAb, and PCR, western blotting and cell cycle analysis confirmed these results. The present findings suggested that blocking extracellular 15-kDa-ALR in U266 cells with an anti-ALR McAb decreased cell proliferation via the MAPK, STAT3 and cell cycle signaling pathways without increasing apoptosis. Thus, 15-kDa-ALR may be a new therapeutic target for myeloma.

Healthcare resource utilization and costs among patients with relapsed and/or refractory multiple myeloma treated with proteasome inhibitors in real-world clinical practice in Germany

AIMS

To assess the real-world healthcare resource utilization (HRU) and costs associated with different proteasome inhibitors (PIs) for the treatment of patients with relapsed and/or refractory multiple myeloma (RRMM) in Germany.

METHODS

We conducted a retrospective medical chart review of treatment patterns, outcomes, and HRU for patients with RRMM treated with bortezomib, carfilzomib, or ixazomib in second- or third-line (2L or 3L) therapy in Germany. Data were collected between 1 January 2017 and 30 June 2017. Costs were calculated based on drug prices and unit costs in Germany.

RESULTS

Physicians provided data on 302 patients. Mean monthly total direct costs per patient receiving PI-based therapy were €7,925 and €10,693 for 2L and 3L, respectively, of which approximately 90% was anti-myeloma drug costs. Overall, the highest costs were associated with patients receiving 3L therapy. Regardless of treatment line, costs were higher for patients who had received a stem cell transplant (SCT) in a previous treatment line than for those who had not; the data suggest that this reflects the use of triplet regimens following a SCT. Patients with a complete response (CR) experienced no unplanned hospitalizations during the study period, whereas patients with progressive disease experienced the highest number of unplanned and planned hospitalizations. In 2L therapy, the highest proportion of patients with a CR was observed in those receiving carfilzomib (12% carfilzomib; 4% bortezomib; 0% ixazomib).

LIMITATIONS

Patients with missing or incomplete follow-up data were included in the study and were accounted for using monthly cost estimates.

CONCLUSIONS

Anti-myeloma drugs were the main contributor to total HRU costs associated with RRMM in Germany. Improved treatment response was associated with lower costs and reduced hospitalizations.

Ixazomib, lenalidomide, and dexamethasone is effective and well tolerated in multiply relapsed (≥2nd relapse) refractory myeloma: a multicenter real world UK experience

There are limited real world data on ixazomib, lenalidomide, and dexamethasone (IRd) in multiply relapsed myeloma. We analyzed outcomes of 116 patients who received IRd predominantly at second and subsequent relapse including those refractory to proteasome inhibitors (PIs). With a median follow up 16.3 months, the overall response rate was 66.9%; median progression-free survival (PFS) was 17.7 months with median overall survival (OS) not reached (NR). PFS and OS were significantly shorter in advanced disease (PFS; 12.6 vs. 21.2 months (p = .01), OS; 15.9 months vs. NR (p = .01) for ISS3 vs. ISS 1&2, respectively). PFS and OS were significantly shorter in clinical high risk (CHR) compared to standard risk (SR) patients (PFS; 9.3 months vs. NR (p = .001), OS; 11.5 months vs. NR (p < .001), respectively). There was a trend toward shorter PFS in PI-refractory patients 13.7 vs. 19.6 months for non-PI refractory (p = .2). The triplet combination was generally well tolerated.

Extramedullary Disease in Multiple Myeloma

PURPOSE OF REVIEW

Extramedullary disease (EMD) is a rare but recognized manifestation of multiple myeloma (MM), characterized by involvement of several organs including skin, liver, lymphatic system, pleura, and central nervous system. The incidence is about 3-5% in newly diagnosed MM patients, but has been reported in up to 20% patients in the relapsed MM setting.

RECENT FINDINGS

Presence of EMD has been associated with more aggressive phenotype of MM, elevated serum lactate dehydrogenase (LDH) enzyme, and high-risk cytogenetics [deletion 17p, translocation (4;14), translocation (14;16)]. There are several hypotheses of how EMD occurs, including factors leading to bone marrow emancipation and hematogenous spread. The treatment schema usually follows that of high-risk MM. The current review summarizes the disease characterization data, along with available data on clinical activity of available anti-MM agents for this entity.

Targeting CD47/TNFAIP8 by miR-155 overcomes drug resistance and inhibits tumor growth through induction of phagocytosis and apoptosis in multiple myeloma

The mechanisms of drug resistance in multiple myeloma are poorly understood. Here we show that CD47, an integrin-associated receptor, is significantly upregulated in drug resistant myeloma cells in comparison with parental cells, and that high expression of CD47 detected by immunohistochemistry is associated with shorter progression free and overall survivals in multiple myeloma patients. We show that miR-155 is expressed at low levels in drug resistant myeloma cells and is a direct regulator of CD47 through its 3'UTR. Furthermore, low miR-155 levels are associated with advanced stages of disease. MiR-155 overexpression suppressed CD47 expression on myeloma cell surface, leading to induction of phagocytosis of myeloma cells by macrophages and inhibition of tumor growth. MiR-155 overexpression also re-sensitized drug-resistant myeloma cells to bortezomib leading to cell death through targeting TNFAIP8, a negative mediator of apoptosis in vitro and in vivo. Thus, miR-155 mimics may serve as a promising new therapeutic modality by promoting phagocytosis and inducing apoptosis in patients with refractory/relapsed multiple myeloma.

Pomalidomide, dexamethasone, and daratumumab in relapsed refractory multiple myeloma after lenalidomide treatment

Patients with multiple myeloma who have relapsed after or become refractory to lenalidomide in early treatment lines represent a clinically important population in need of effective therapies. The safety and efficacy of pomalidomide, low-dose dexamethasone, and daratumumab was evaluated in lenalidomide-pretreated patients with relapsed or refractory multiple myeloma (RRMM) after one to two prior treatment lines in the phase 2 MM-014 study. Patients received pomalidomide 4 mg daily from days 1-21 and dexamethasone 40 mg weekly (28-day cycles). Daratumumab 16 mg/kg was administered per label. Primary endpoint was overall response rate (ORR); secondary endpoints included progression-free survival (PFS) and safety. Per protocol, all patients (N = 112) had received lenalidomide in their most recent prior regimen (75.0% lenalidomide refractory). ORR was 77.7% (76.2% in lenalidomide-refractory patients); median follow-up was 17.2 months. Median PFS was not reached (1-year PFS rate 75.1%). The most common hematologic grade 3/4 treatment-emergent adverse event was neutropenia (62.5%). Grade 3/4 infections were reported in 31.3% of patients, including 13.4% with grade 3/4 pneumonia. These results demonstrate the safety and efficacy of pomalidomide-based therapy as early as second line in patients with RRMM, even immediately after lenalidomide failure, indicating that switching from the immunomodulatory agent class is not necessary.

Monoclonal Antibodies: Leading Actors in the Relapsed/Refractory Multiple Myeloma Treatment

Multiple myeloma is a complex hematologic malignancy, and despite a survival improvement related to the growing number of available therapeutic options since 2000s, it remains an incurable disease with most patients experiencing relapse. However, therapeutic options for this disease are constantly evolving and immunotherapy is becoming the mainstay of the therapeutic armamentarium of Multiple Myeloma (MM), starting with monoclonal antibodies (MoAbs) as elotuzumab, daratumumab and isatuximab. Elotuzumab, the first in class targeting SLAMF7, in combination with lenalidomide and dexamethasone and daratumumab, directed against CD38, in combination with Rd and with bortezomib and dexamethasone (Vd), have been approved for the treatment of relapsed/refractory MM (RRMM) after they demonstrated excellent efficacy. More recently, another anti-CD38 MoAb named isatuximab was approved by FDA in combination with pomalidomide-dexamethasone (Pd) in the same setting. Many phase II and III trials with regimens containing these MoAbs are ongoing, and when available, preliminary data are very encouraging. In this review we will describe the results of major clinical studies that have been conducted with elotuzumab, daratumumab and isatuximab in RRMM, focusing on phase III trials. Moreover, we will summarized the emerging MoAbs-based combinations in the RRMM landscape.

Treatment of elderly patients with refractory/relapsed multiple myeloma: oral drugs adherence and the COVID-19 outbreak

Once the treatment of refractory/relapsed multiple myeloma in the elderly is greatly influenced by the adherence of patients and family members, clinicians should be aware of patients' behavior and lifestyle, as it may influence the individual treatment plan for each patient. Furthermore, treatment with oral chemotherapy is of special value during the COVID-19 outbreak. Multidisciplinary healthcare involvement is crucial in the management of polypharmacy, adverse events and dose adjustment due to comorbidities and natural loss of renal function with age. Oral drugs simplify intake, reduce hospital visits, and improve autonomy and quality of life. However, although oral drugs have advantages, they also transfer control and responsibility from the healthcare professional to the patient, who must be able to understand and follow the directions given. Therefore, patient education and communication with healthcare professionals are critical for adherence.

Pomalidomide, bortezomib, and dexamethasone for multiple myeloma previously treated with lenalidomide (OPTIMISMM): outcomes by prior treatment at first relapse

In the phase 3 OPTIMISMM trial, pomalidomide, bortezomib, and dexamethasone (PVd) demonstrated superior efficacy vs bortezomib and dexamethasone (Vd) in patients with relapsed or refractory multiple myeloma previously treated with lenalidomide, including those refractory to lenalidomide. This analysis evaluated outcomes in patients at first relapse (N = 226) by lenalidomide-refractory status, prior bortezomib exposure, and prior stem cell transplant (SCT). Second-line PVd significantly improved PFS vs Vd in lenalidomide-refractory (17.8 vs 9.5 months; P = 0.0276) and lenalidomide-nonrefractory patients (22.0 vs 12.0 months; P = 0.0491), patients with prior bortezomib (17.8 vs 12.0 months; P = 0.0068), and patients with (22.0 vs 13.8 months; P = 0.0241) or without (16.5 vs 9.5 months; P = 0.0454) prior SCT. In patients without prior bortezomib, median PFS was 20.7 vs 9.5 months (P = 0.1055). Significant improvement in overall response rate was also observed with PVd vs Vd in lenalidomide-refractory (85.9% vs 50.8%; P < 0.001) and lenalidomide-nonrefractory (95.7% vs 60.0%; P < 0.001) patients, with similar results regardless of prior bortezomib or SCT. No new safety signals were observed. These data demonstrate the benefit of PVd at first relapse, including immediately after upfront lenalidomide treatment failure and other common first-line treatments.

The clinical management of lenalidomide-based therapy in patients with newly diagnosed multiple myeloma

Lenalidomide is an integral, yet evolving, part of current treatment pathways for both transplant-eligible and transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM). It is approved in combination with dexamethasone as first-line therapy for transplant-ineligible patients with NDMM, and as maintenance treatment following autologous stem cell transplantation (ASCT). Although strong clinical trial evidence has supported the integration of lenalidomide into current treatment paradigms for NDMM, applying those paradigms to individual patients and determining which patients are most likely to benefit from lenalidomide treatment are more complex. In this paper, we utilize the available clinical trial evidence to provide recommendations for patient selection and lenalidomide dosing in both the first-line setting in patients ineligible for ASCT and the maintenance setting in patients who have undergone ASCT. In addition, we provide guidance on management of those adverse events that are most commonly associated with lenalidomide treatment, and consider the optimal selection and sequencing of next-line agents following long-term frontline or maintenance treatment with lenalidomide.

A Noninterventional, Observational, European Post-Authorization Safety Study of Patients With Relapsed/Refractory Multiple Myeloma Treated With Lenalidomide

INTRODUCTION

Lenalidomide plus dexamethasone is effective and well tolerated in relapsed/refractory multiple myeloma (RRMM). In this observational, noninterventional European post-authorization safety study, the safety profile of lenalidomide plus dexamethasone was investigated and compared with that of other agents in the treatment of RRMM in a real-world setting.

PATIENTS AND METHODS

Patients had received ≥ 1 prior antimyeloma therapy; prior lenalidomide was excluded. Treatment was per investigator's routine practice. Adverse events were analyzed by incidence rates per 100 person-years to account for differences in observation length and treatment duration.

RESULTS

In total, 2150 patients initiated lenalidomide, and 1479 initiated any other antimyeloma therapy, predominately bortezomib (80.3%), which was primarily administered intravenously (74.3%). The incidence rate of neuropathy was lower with lenalidomide (10.5) than with bortezomib (78.9) or thalidomide (38.7). Lenalidomide also had a lower incidence rate of infections (68.7) versus bortezomib (95.9) and thalidomide (76.0). Conversely, the incidence rate of neutropenia was higher with lenalidomide (38.0) than with bortezomib (18.2) or thalidomide (25.7). The incidence rates of thrombocytopenia were 24.4, 40.4, and 14.4 with lenalidomide, bortezomib, and thalidomide, respectively.

CONCLUSION

No new safety signals for lenalidomide were identified in this study, which is the largest prospective real-world European study of lenalidomide in patients with RRMM to date. These results confirm that the safety profile of lenalidomide plus dexamethasone in RRMM in a real-world setting is comparable to that reported in clinical trials.

Expert Panel Consensus Statement for Proper Evaluation of First Relapse in Multiple Myeloma

PURPOSE OF REVIEW

A working group of six expert physicians convened to assess the spectrum of multiple myeloma relapse presentations, discussed the features that can define the disease as aggressive and not aggressive, and established whether this information could help in selecting treatment together with the characteristics of disease and of patients and type of prior therapy.

RECENT FINDINGS

The working group agreed that relapse should be distinguished between biochemical and clinical according to IMWG. Moreover, the expert panel defined "aggressive disease" as a clinical condition that requires therapy able to induce a rapid and as deep as possible response to release symptoms and to avoid impending danger of new events. According to this definition, relapse was considered aggressive if it presents with at least one of the following features: doubling of M protein rate over 2 months, renal insufficiency, hypercalcemia, extramedullary disease, elevated LDH, high plasma cell proliferative index, presence of plasma cells in peripheral blood, or skeletal-related complications. Moreover, the panel agreed that this classification can be useful to choose therapy in first relapse together with other patient, disease, and prior therapy characteristics. So, this item was included in a new therapeutic algorithm. The treatment choice in MM at relapse is wider than in the past with the availability of many new therapeutic regimens leading to increased diversity of approaches and relevant risk of inappropriate treatment decisions. A practical classification of relapses into aggressive or non-aggressive, included in a decisional algorithm on MM management at first relapse, could help to make the appropriate treatment decisions.

Pomalidomide-bortezomib-dexamethasone in relapsed or refractory multiple myeloma: Japanese subset analysis of OPTIMISMM

In the phase 3 OPTIMISMM trial, pomalidomide, bortezomib and dexamethasone (PVd) significantly improved the progression-free survival (PFS) and the overall response rate (ORR) vs bortezomib and dexamethasone (Vd) in patients with relapsed or refractory multiple myeloma. All patients were previously treated with lenalidomide (70% refractory to lenalidomide) and had received one to three prior regimens. Here we report the first efficacy and safety analysis of PVd vs Vd in Japanese patients with relapsed or refractory multiple myeloma. Seventeen patients enrolled in the OPTIMISMM trial in Japan. With a median follow-up of 14.8 months, the median PFS was 17.6 months with PVd (n = 12) vs 4.4 months with Vd (n = 5), and the ORR was 100% vs 60.0%, respectively. The safety profile was as expected for PVd. Toxicities were managed with dose reductions and interruptions, and no patients discontinued PVd due to treatment-emergent adverse events. These results are consistent with those in the overall OPTIMISMM patient population and confirm the clinical benefit of PVd in Japanese patients.

MARCKS inhibition cooperates with autophagy antagonists to potentiate the effect of standard therapy against drug-resistant multiple myeloma

Overexpression of Myristoylated Alanine-Rich C Kinase Substrate (MARCKS) is implicated in drug resistance and progression of multiple myeloma (MM). The basis for MARCKS induction and impact on MM are not known. Here we show that microRNA-34a (miR-34a), regulates MARCKS translation and is under-expressed in drug-resistant MM cells, leading to increased MARCKS protein level. Over-expression of miR-34a reduces MARCKS expression and sensitizes resistant cells to anti-myeloma drugs. A MARCKS peptide inhibitor (MPS) exerts a dose dependent cytotoxic effect on drug-resistant MM cells with minimal cytotoxicity to normal hematopoietic cells. MPS synergizes with the proteasomal-inhibitor bortezomib to effectively kill drug-resistant MM cells both in vitro and in a xenograft model of MM. While MARCKS inhibition killed MM cells, it also enhanced a pro-survival autophagic pathway that sustained growth following MARCKS inhibition. In accordance, combined treatment with MARCKS antagonists, bortezomib and the autophagy inhibitor, chloroquine, significantly diminished tumor growth in drug-resistant MM cell lines as well as primary MM cells. This study uncovers a mechanism of drug resistance involving miR-34a-MARCKS autoregulatory loop and provides a framework for a potentially new therapeutic strategy to overcome drug resistance in multiple myeloma.

DCEP and bendamustine/prednisone as salvage therapy for quad- and penta-refractory multiple myeloma

Multiple myeloma (MM) almost invariably progresses through novel therapies. Patients with quad-refractory MM (refractory to bortezomib, carfilzomib, lenalidomide, and pomalidomide) and penta-refractory MM (additional refractoriness to daratumumab) have few treatment options. Two chemotherapy regimens, bendamustine/prednisone (BP) and dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP), are often used in quad- and penta-refractory MM, but there are limited data on outcomes in this heavily pre-treated population. We conducted a single-center retrospective study to identify all patients who received DCEP and/or BP for quad- or penta-refractory MM. Disease response and refractoriness were defined by International Myeloma Working Group criteria. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), and duration of response (DOR). We identified 27 patients who received BP for quad- or penta-refractory MM. The median number of prior lines of therapy was 6. The ORR for BP was 26%. The median PFS for BP was 1.4 months (95% CI 1.1-1.6) and median OS was 8.7 months (95% CI 2.3-15.0). Patients treated with cyclophosphamide had less response to BP. Thirty-one patients received DCEP for quad-refractory or penta-refractory MM. The median number of prior treatment regimens was 8. The ORR to DCEP was 35%. The median PFS was 2.7 months (95% CI 1.5-3.8) and median OS was 6.2 months (95% CI 4.4-7.8). DCEP and BP retain efficacy in quad- and penta-refractory MM. Our analysis supports prospective study of these regimens, possibly in combination or in comparison with other agents in this area of unmet need.

Multiple Myeloma: Available Therapies and Causes of Drug Resistance

Multiple myeloma (MM) is the second most common blood cancer. Treatments for MM include corticosteroids, alkylating agents, anthracyclines, proteasome inhibitors, immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies. Survival outcomes have improved substantially due to the introduction of many of these drugs allied with their rational use. Nonetheless, MM patients successively relapse after one or more treatment regimens or become refractory, mostly due to drug resistance. This review focuses on the main drugs used in MM treatment and on causes of drug resistance, including cytogenetic, genetic and epigenetic alterations, abnormal drug transport and metabolism, dysregulation of apoptosis, autophagy activation and other intracellular signaling pathways, the presence of cancer stem cells, and the tumor microenvironment. Furthermore, we highlight the areas that need to be further clarified in an attempt to identify novel therapeutic targets to counteract drug resistance in MM patients.

Pomalidomide plus low-dose dexamethasone in relapsed refractory multiple myeloma after lenalidomide treatment failure

Patients with relapsed/refractory multiple myeloma (RRMM) for whom the benefits of lenalidomide have been exhausted in early treatment lines need effective therapies. In cohort A of the phase 2 MM-014 trial, we examined the safety and efficacy of pomalidomide plus low-dose dexamethasone immediately after lenalidomide-based treatment failure in patients with RRMM and two prior lines of therapy. Pomalidomide 4 mg was given on days 1 to 21 of 28-day cycles. Dexamethasone 40 mg (20 mg for patients aged >75 years) was given on days 1, 8, 15 and 22 of 28-day cycles. The primary endpoint was overall response rate (ORR), and secondary endpoints included progression-free survival (PFS), overall survival (OS) and safety. The intention-to-treat population comprised 56 patients; all received prior lenalidomide (87·5% lenalidomide refractory) and 39 (69·6%) received prior bortezomib. ORR was 32·1% (28·2% in the prior-bortezomib subgroup). Median PFS was 12·2 months (7·9 months in the prior-bortezomib subgroup). Median OS was 41·7 months (38·6 months in the prior-bortezomib subgroup). The most common grade 3/4 treatment-emergent adverse events were anaemia (25·0%), pneumonia (14·3%) and fatigue (14·3%). These findings support earlier sequencing of pomalidomide-based therapy in lenalidomide-pretreated patients with RRMM, including those who have become refractory to lenalidomide. Trial registration: www.ClinicalTrials.gov identifier NCT01946477.

Updates on CAR T-cell therapy in B-cell malignancies

By increasing disease-free survival and offering the potential for long-term cure, chimeric antigen receptor (CAR) T-cell therapy has dramatically expanded therapeutic options among those with high-risk B-cell malignancies. As CAR T-cell utilization evolves however, novel challenges are generated. These include determining how to optimally integrate CAR T cells into standard of care and overcoming mechanisms of resistance to CAR T-cell therapy, such as evolutionary stress induced on cancer cells leading to immunophenotypic changes that allow leukemia to evade this targeted therapy. Compounding these challenges are the limited ability to determine differences between various CAR T-cell constructs, understanding the generalizability of trial outcomes from multiple sites utilizing unique CAR manufacturing strategies, and comparing distinct criteria for toxicity grading while defining optimal management. Additionally, as understanding of CAR behavior in humans has developed, strategies have appropriately evolved to proactively mitigate toxicities. These challenges offer complimentary insights and guide next steps to enhance the efficacy of this novel therapeutic modality. With a focus on B-cell malignancies as the paradigm for effective CAR T-cell therapy, this review describes advances in the field as well as current challenges and future directions.

Bortezomib for the Treatment of Hematologic Malignancies: 15 Years Later

Bortezomib is a dipeptidyl boronic acid that selectively inhibits the ubiquitin proteasome pathway, which plays a role in the degradation of many intracellular proteins. It is the first-in-class selective and reversible inhibitor of the 26S proteasome, with antiproliferative and antitumor activity. It exerts its anti-neoplastic action mainly via the inhibition of the nuclear factor-κB pathway components associated with cell proliferation, apoptosis, and angiogenesis. The drug has revolutionized the treatment of multiple myeloma and, more recently, mantle cell lymphoma. In 2003, bortezomib received accelerated approval from the US Food and Drug Administration for the treatment of relapsed/refractory multiple myeloma and in 2008 for patients with previously untreated multiple myeloma. In 2006, bortezomib was approved for the treatment of refractory/relapsed mantle cell lymphoma and, in 2014, for previously untreated mantle cell lymphoma. Bortezomib has also demonstrated clinical efficacy both as a single drug and in combination with other agents in light chain amyloidosis, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia, and peripheral T-cell lymphomas. Furthermore, continued clinical studies are required to confirm its value for patients with indolent and aggressive B-cell non-Hodgkin lymphomas and acute leukemias.

A Rare Case of Ixazomib-Induced Cutaneous Necrotizing Vasculitis in a Patient with Relapsed Myeloma

Ixazomib is the only oral proteasome inhibitor used in relapsed/refractory myeloma. Cutaneous side effects due to ixazomib have been documented in the literature; however, cutaneous necrotizing vasculitis is extremely rare. We describe a case of a 74-year-old man with relapsed multiple myeloma who was started on ixazomib, lenalidomide, and dexamethasone. He developed several skin lesions that were biopsied and revealed cutaneous necrotizing vasculitis. Ixazomib was held with resolution of the vasculitic lesions and restarted with dexamethasone to 20 mg on the day of treatment and 20 mg dose the day after treatment.

A Network Analysis of Multiple Myeloma Related Gene Signatures

Multiple myeloma (MM) is the second most prevalent hematological cancer. MM is a complex and heterogeneous disease, and thus, it is essential to leverage omics data from large MM cohorts to understand the molecular mechanisms underlying MM tumorigenesis, progression, and drug responses, which may aid in the development of better treatments. In this study, we analyzed gene expression, copy number variation, and clinical data from the Multiple Myeloma Research Consortium (MMRC) dataset and constructed a multiple myeloma molecular causal network (M3CN). The M3CN was used to unify eight prognostic gene signatures in the literature that shared very few genes between them, resulting in a prognostic subnetwork of the M3CN, consisting of 178 genes that were enriched for genes involved in cell cycle (fold enrichment = 8.4, p value = 6.1 × 10⁻²⁶). The M3CN was further used to characterize immunomodulators and proteasome inhibitors for MM, demonstrating the pleiotropic effects of these drugs, with drug-response signature genes enriched across multiple M3CN subnetworks. Network analyses indicated potential links between these drug-response subnetworks and the prognostic subnetwork. To elucidate the structure of these important MM subnetworks, we identified putative key regulators predicted to modulate the state of these subnetworks. Finally, to assess the predictive power of our network-based models, we stratified MM patients in an independent cohort, the MMRF-CoMMpass study, based on the prognostic subnetwork, and compared the performance of this subnetwork against other signatures in the literature. We show that the M3CN-derived prognostic subnetwork achieved the best separation between different risk groups in terms of log-rank test p-values and hazard ratios. In summary, this work demonstrates the power of a probabilistic causal network approach to understanding molecular mechanisms underlying the different MM signatures.

The Clinical Course of Multiple Myeloma in the Era of Novel Agents: A Retrospective, Single-Center, Real-World Study

In this retrospective study we reviewed the clinical course of every patient with multiple myeloma treated from 2006 to 2016 at Vejle Hospital: 303 patients with a median age of 69 years at diagnosis received a median of four (range 1–18) lines of therapy; 149 in a 2006–2010 cohort and 154 in a 2011–2016 cohort. After initiation of treatment, the median decrease in the number of patients per each subsequent line of therapy was 22%. Lenalidomide-dexamethasone (n = 156), bortezomib-dexamethasone (n = 107), and bortezomib-lenalidomide-dexamethasone (n = 84) were the most commonly used regimens. The partial response or better rate was 78%, 58%, 55%, and 44% in lines of therapy one to four, respectively. The median (95% confidence interval [CI]) progression-free survival was 18 (15–22), 10 (8–13), 8 (7–10), and 6 (4–8) months in lines of therapy one to four, respectively. The median (95% CI) overall survival (OS) was 4.1 (3.7–4.8) years. Compared with the 2006–2010 cohort, patients in the 2011–2016 cohort had longer OS; 5.3 (4.7 to not reached) versus 3.4 (2.7–4.0) years, p < 0.0001. This was especially true in patients not treated with high-dose therapy and autologous stem cell transplantation; 4.7 (3.2–5.9) versus 2.6 (2.0–3.3) years, p = 0.0052. Patients in the 2011–2016 cohort were on treatment during a greater part of their life and had higher exposure to high-dose melphalan with autologous stem cell transplantation, lenalidomide, pomalidomide, daratumumab, and carfilzomib.

Phase 1 study of selinexor plus carfilzomib and dexamethasone for the treatment of relapsed/refractory multiple myeloma

Selinexor, an oral Selective Inhibitor of Nuclear Export, targets Exportin 1 (XPO1, also termed CRM1). Non-clinical studies support combining selinexor with proteasome inhibitors (PIs) and corticosteroids to overcome resistance in relapsed/refractory multiple myeloma (RRMM). We conducted a phase I dose-escalation trial of twice-weekly selinexor in combination with carfilzomib and dexamethasone (SKd) to determine maximum tolerated dose in patients with RRMM (N = 21), with an expansion cohort to assess activity in carfilzomib-refractory disease and identify a recommended phase II dose (RP2D). During dose escalation, there was one dose-limiting toxicity (cardiac failure). The RP2D of twice-weekly SKd was selinexor 60 mg, carfilzomib 20/27 mg/m2 and dexamethasone 20 mg. The most common grade 3/4 treatment-emergent adverse events included thrombocytopenia (71%), anaemia (33%), lymphopenia (33%), neutropenia (33%) and infections (24%). Rates of ≥minimal response, ≥partial response and very good partial response were 71%, 48% and 14%, respectively; similar response outcomes were observed for dual-class refractory (PI and immunomodulatory drug)/quad-exposed (carfilzomib, bortezomib, lenalidomide and pomalidomide) patients (n = 17), and patients refractory to carfilzomib in last line of therapy (n = 13). Median progression-free survival was 3·7 months, and overall survival was 22·4 months in the overall population. SKd was tolerable and re-established disease control in RRMM patients, including carfilzomib-refractory patients. Registered at ClinicalTrials.gov (NCT02199665).

High-Risk Multiple Myeloma: Integrated Clinical and Omics Approach Dissects the Neoplastic Clone and the Tumor Microenvironment

Multiple myeloma (MM) is a genetically heterogeneous disease that includes a subgroup of 10–15% of patients facing dismal survival despite the most intensive treatment. Despite improvements in biological knowledge, MM is still an incurable neoplasia, and therapeutic options able to overcome the relapsing/refractory behavior represent an unmet clinical need. The aim of this review is to provide an integrated clinical and biological overview of high-risk MM, discussing novel therapeutic perspectives, targeting the neoplastic clone and its microenvironment. The dissection of the molecular determinants of the aggressive phenotypes and drug-resistance can foster a better tailored clinical management of the high-risk profile and therapy-refractoriness. Among the current clinical difficulties in MM, patients’ management by manipulating the tumor niche represents a major challenge. The angiogenesis and the stromal infiltrate constitute pivotal mechanisms of a mutual collaboration between MM and the non-tumoral counterpart. Immuno-modulatory and anti-angiogenic therapy hold great efficacy, but variable and unpredictable responses in high-risk MM. The comprehensive understanding of the genetic heterogeneity and MM high-risk ecosystem enforce a systematic bench-to-bedside approach. Here, we provide a broad outlook of novel druggable targets. We also summarize the existing multi-omics-based risk profiling tools, in order to better select candidates for dual immune/vasculogenesis targeting.

Weekly carfilzomib, lenalidomide, and dexamethasone in relapsed or refractory multiple myeloma: A phase 1b study

Twice-weekly carfilzomib (27 mg/m2 ) with lenalidomide-dexamethasone (KRd) is a standard-of-care in relapsed or refractory multiple myeloma (RRMM). This phase 1b study evaluated KRd with once-weekly carfilzomib in RRMM. Patients received carfilzomib (30-minute infusion; 56 or 70mg/m2 ) on days 1, 8, and 15; lenalidomide 25 mg on days 1-21; and dexamethasone 40 mg on days 1, 8, 15, and 22 (day 22 omitted for cycles 9+) of 28-day cycles. Primary objective was safety/tolerability; efficacy was a secondary objective. Fifty-six RRMM patients enrolled: 22 during dose evaluation (56-mg/m2 , n = 10; 70-mg/m2 , n = 12) and 34 during dose expansion (all initiated dosing at 70 mg/m2 ). After 2 fatal adverse events (AEs) during 70-mg/m2 dose expansion, dosage reduction to 56 mg/m2 was permitted. Results are presented for carfilzomib 56-mg/m2 (n = 10) and 70-mg/m2 groups (dose evaluation/expansion; n = 46). Median carfilzomib dose was 53.2 mg/m2 (56-mg/m2 group) and 62.4 mg/m2 (70-mg/m2 group). Grade ≥3 AE rates were 70.0% (56 mg/m2 ) and 69.6% (70 mg/m2 ). Overall response rates were 90.0% (56 mg/m2 ) and 89.1% (70 mg/m2 ); ≥very good partial response rates were 50.0% (56 mg/m2 ) and 73.9% (70 mg/m2 ). Once-weekly KRd was active with acceptable toxicity in RRMM, supporting further evaluation of this regimen.

Selective purging of human multiple myeloma cells from peripheral blood mononuclear cells: a preliminary study

Background

High-dose chemotherapy followed by autologous peripheral blood stem-cell transplantation are standards of therapy for patients diagnosed with multiple myeloma. The purging process to remove contaminating residual myeloma cells could improve patient outcomes. In this study, a purging method of human multiple myeloma cells from peripheral blood mononuclear cells was evaluated.

Materials and methods

The human myeloma cell line RPMI-8226 (Seoul, Korea) was treated with bortezomib (Selleck Chemicals, Houston, TX, USA) or lenalidomide (Sigma Aldrich, St. Louis, MO, USA). The mixture of the human peripheral blood mononuclear cell line PCS-800-011 (ATCC, USA) and RPMI-8226 was treated with bortezomib or lenalidomide for 24 hours. The efficacy of purging myeloma cells was evaluated by 8-color flow cytometric analysis.

Results

The cytotoxicity of bortezomib (10-160 nmol/L) and lenalidomide (200-3,200 nmol/L) was investigated on RPMI-8226 myeloma cell line. A 24-hour incubation with bortezomib at 10, 20, 40, 80, 160 nmol/L induced 5.45%±0.07%, 47.15%±1.20%, 57.15%±0.21%, 72.35%±0.07%, and 84.75%±0.49% growth inhibition in RPMI-8226 cells, respectively. A 24-hour incubation with lenalidomide at 200, 400, 800, 1,600, and 3,200 nmol/L induced 5.45%±0.07%, 7.55%±0.07%, 9.75%±0.35%, 18.25%±0.21%, and 39.75%±0.78% growth inhibition in RPMI-8226 cells, respectively. Bortezomib (40 nmol/L, 24 hours) and lenalidomide (3,200 nmol/L, 24 hours) effectively removed CD38⁺CD138⁺ cells from peripheral mononuclear cells. RPMI-8226 cells showed abberant phenotype CD56⁺/CD45^-.

Conclusion

The results of the present study demonstrated that the bortezomib and lenalidomide treatment in RPMI-8226 multiple myeloma cells effectively removed the contaminated plasma cells.

Preclinical Evaluation of Allogeneic CAR T Cells Targeting BCMA for the Treatment of Multiple Myeloma

Clinical success of autologous CD19-directed chimeric antigen receptor T cells (CAR Ts) in acute lymphoblastic leukemia and non-Hodgkin lymphoma suggests that CAR Ts may be a promising therapy for hematological malignancies, including multiple myeloma. However, autologous CAR T therapies have limitations that may impact clinical use, including lengthy vein-to-vein time and manufacturing constraints. Allogeneic CAR T (AlloCAR T) therapies may overcome these innate limitations of autologous CAR T therapies. Unlike autologous cell therapies, AlloCAR T therapies employ healthy donor T cells that are isolated in a manufacturing facility, engineered to express CARs with specificity for a tumor-associated antigen, and modified using gene-editing technology to limit T cell receptor (TCR)-mediated immune responses. Here, transcription activator-like effector nuclease (TALEN) gene editing of B cell maturation antigen (BCMA) CAR Ts was used to confer lymphodepletion resistance and reduced graft-versus-host disease (GvHD) potential. The safety profile of allogeneic BCMA CAR Ts was further enhanced by incorporating a CD20 mimotope-based intra-CAR off switch enabling effective CAR T elimination in the presence of rituximab. Allogeneic BCMA CAR Ts induced sustained antitumor responses in mice supplemented with human cytokines, and, most importantly, maintained their phenotype and potency after scale-up manufacturing. This novel off-the-shelf allogeneic BCMA CAR T product is a promising candidate for clinical evaluation.

A real-world comparative analysis of carfilzomib and other systemic multiple myeloma chemotherapies in a US community oncology setting

Background

Most multiple myeloma (MM) patients ultimately progress, with remission duration decreasing after first relapse. Recently, novel agents have been approved for the treatment of relapsed MM. There is a paucity of real-world data on these treatments. We sought to compare time to next treatment (TTNT) in MM patients in their second line of therapy (LOT2), treated with common proteasome inhibitor (PI)-based triplets.

Methods

Adult MM patients who received carfilzomib (K) between 1 November 2013 and 29 February 2016 at US Oncology Network (USON) clinics utilizing iKnowMed™ electronic health records (EHRs) were identified. Patients were included if they were ⩾18 years of age, not enrolled in clinical trials, had ⩾2 visits at a USON clinic and received LOT2 regimens consisting of: K+lenalidomide with steroid (KRd), bortezomib+lenalidomide with steroid (VRd), or bortezomib+cyclophosphamide with steroid (VCyd). TTNT was estimated from LOT2 initiation to LOT3 initiation using the Kaplan-Meier method, and hazard ratios (HRs) were estimated using Cox modeling.

Results

A total of 718 patients received a K-containing regimen sometime during their MM treatment (LOT1 to LOT5). Of these, 156 patients received: KRd (n = 112; 71.8%), VRd (n =27; 17.3%), or VCyd (n = 17; 10.9%). Baseline characteristics were similar between groups (mean age: 64.8 years; 58% male). Median TTNT was longest for KRd [25.3 months; 95% confidence interval (CI): 19.71-NR], versus VRd or VCyd (VRd median TTNT: 10.2 months, 95% CI: 4.24-12.71; VCyd: 6.5 months, 95% CI: 3.02-12.78; log-rank p < 0.0001). The adjusted HR for KRd was 0.19 (95% CI: 0.11-0.37), compared with VRd.

Conclusions

Considering the real-world nature of these data, the median TTNT observed with KRd was relatively consistent, with progression-free survival (PFS) for KRd observed in the phase III ASPIRE trial (median PFS: ITT population = 26.3 months; LOT2 = 29.6 months). Patients who received KRd at first relapse had significantly longer TTNT, compared with those on VRd or VCyd, confirming the value of KRd as an important treatment option for relapsed MM.

Navigating the treatment landscape in multiple myeloma: which combinations to use and when?

Multiple myeloma is one of the most common hematological malignancies, affecting mainly elderly patients. The treatment landscape for the management of this disease has evolved significantly over the past 15 years, and a vast array of therapeutics is now available, including immunomodulatory drugs, proteasome inhibitors, histone deacetylase inhibitors, and monoclonal antibodies. As a result, deciding which drugs to use and when, and whether these should be used in a particular order or combination, can be challenging. Although combination regimens are often associated with deeper responses and better long-term outcomes than monotherapy, and are becoming the standard of care, they may result in significant incremental toxicity; hence, a sequential approach may be more appropriate for some patients. In particular, treatment choices can vary depending on whether the patient has newly diagnosed multiple myeloma, is eligible for transplant, has relapsed and/or refractory multiple myeloma, or is considered to have high-risk disease. In this review, we discuss factors to be taken into account when making treatment decisions in each of these settings. We also briefly discuss possible therapeutic strategies involving agents that may become available in the future.

Targeting CD74 in multiple myeloma with the novel, site-specific antibody-drug conjugate STRO-001

STRO-001 is a site-specific, predominantly single-species, fully human, aglycosylated anti-CD74 antibody-drug conjugate incorporating a non-cleavable linker-maytansinoid warhead with a drug-antibody ratio of 2 which was produced by a novel cell-free antibody synthesis platform. We examined the potential pharmacodynamics and anti-tumor effects of STRO-001 in multiple myeloma (MM). CD74 expression was assessed in MM cell lines and primary bone marrow (BM) MM biopsies. CD74 mRNA was detectable in CD138+ enriched plasma cells from 100% (892/892) of patients with newly diagnosed MM. Immunohistochemistry confirmed CD74 expression in 35/36 BM biopsies from patients with newly diagnosed and relapsed/refractory MM. Cytotoxicity assays demonstrated nanomolar STRO-001 potency in 4/6 MM cell lines. In ARP-1 and MM.1S tumor-bearing mice, repeat STRO-001 dosing provided significant antitumor activity with eradication of malignant hCD138+ BM plasma cells and prolonged survival. In a luciferase-expressing MM.1S xenograft model, dose-dependent STRO-001 efficacy was confirmed using bioluminescent imaging and BM tumor burden quantification. Consistent with the intended pharmacodynamic effect, STRO-001 induced dose-responsive, reversible B-cell and monocyte depletion in cynomolgus monkeys, up to a maximum tolerated 10 mg/kg, with no evidence of off-target toxicity. Collectively, these data suggest that STRO-001 is a promising therapeutic agent for the treatment of MM.

A comparison of the efficacy of immunomodulatory-free regimens in relapsed or refractory multiple myeloma: a network meta-analysis

Treatment history influences the outcomes of subsequent therapies in patients with relapsed or refractory multiple myeloma (RRMM) and needs to be considered when deciding which treatment to use next. To assess the relative merits of immunomodulatory (IMiD)-free treatments, a systematic literature review (SLR) was conducted to identify relevant randomized controlled trials in patients with RRMM. A network meta-analysis (NMA) was performed to assess various IMiD-free regimens, including bortezomib and dexamethasone (Vd)-based treatments, and to explore differences in patient outcomes. The SLR identified 52 articles, from which four trials were ultimately included in the base-case NMA. The NMA showed that daratumumab plus Vd (DVd) provided a significant advantage in prolonging progression-free survival. Similar trends were observed for overall survival and overall response. Across all outcomes, DVd had the highest probability of being the best treatment. These findings suggest that DVd may provide superior clinical outcomes for RRMM patients suitable for IMiD-free regimens.

Targeting c-met receptor tyrosine kinase by the DNA aptamer SL1 as a potential novel therapeutic option for myeloma

Hepatocyte growth factor (HGF)/c‐met pathway activation has been implicated in the pathogenesis of multiple myeloma (MM), and blocking this pathway has been considered a rational therapeutic strategy for treating MM. Aptamers are single‐stranded nucleic acid molecules that fold into complex 3D structures and bind to a variety of targets. Recently, it was reported that DNA aptamer SL1 exhibited high specificity and affinity for c‐met and inhibited HGF/c‐met signaling in SNU‐5 cells. However, as the first c‐met‐targeted DNA aptamer to be identified, application of SL1 to myeloma treatment requires further investigation. Here, we explore the potential application of SL1 in MM. Our results indicated that c‐met expression is gradually increased in MM patients and contributes to poor outcomes. SL1 selectively bound to c‐met‐positive MM cells but not to normal B cells and suppressed the growth, migration and adhesion of MM cells in vitro in a co‐culture model performed with HS5 cells, wherein SL1 inhibited HGF‐induced activation of c‐met signaling. In vivo and ex vivo fluorescence imaging showed that SL1 accumulated in the c‐met positive tumour areas. In addition, SL1 was active against CD138+ primary MM cells and displayed a synergistic inhibition effect with bortezomib. Collectively, our data suggested that SL1 could be beneficial as a c‐met targeted antagonist in MM.

Daratumumab plus lenalidomide and dexamethasone versus lenalidomide and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of POLLUX

In the POLLUX study, daratumumab plus lenalidomide/dexamethasone significantly reduced risk of progression/death versus lenalidomide/dexamethasone alone in relapsed/refractory multiple myeloma. We provide one additional year of follow up and include the effect on minimal residual disease and in clinically relevant subgroups. After 25.4 months of follow up, daratumumab plus lenalidomide/dexamethasone prolonged progression-free survival versus lenalidomide/dexamethasone alone (median not reached vs. 17.5 months; hazard ratio, 0.41; 95% confidence interval, 0.31-0.53; P<0.0001). The overall response rate was 92.9% versus 76.4%, and 51.2% versus 21.0% achieved a complete response or better, respectively (both P<0.0001). At the 10⁻⁵ sensitivity threshold, 26.2% versus 6.4% were minimal residual disease–negative, respectively (P<0.0001). Post hoc analyses of clinically relevant patient subgroups demonstrated that progression-free survival was significantly prolonged for daratumumab plus lenalidomide/dexamethasone versus lenalidomide/dexamethasone regardless of number of prior lines of therapy. Patients previously treated with lenalidomide or thalidomide and those refractory to bortezomib received similar benefits (all P<0.01). Treatment benefit with daratumumab plus lenalidomide/dexamethasone was maintained in high-risk patients (median progression-free survival 22.6 vs. 10.2 months; hazard ratio, 0.53; 95% confidence interval, 0.25-1.13; P=0.0921) and patients with treatment-free intervals of >12 and ≤12 months and >6 and ≤6 months. No new safety signals were observed. In relapsed/refractory multiple myeloma patients, daratumumab plus lenalidomide/dexamethasone continued to improve progression-free survival and deepen responses versus lenalidomide/dexamethasone. Trial Registration: clinicaltrials.gov identifier: 02076009.

A look at treatment strategies for relapsed multiple myeloma

INTRODUCTION

Multiple myeloma treatment considerably improved during the past decade, thanks to novel effective drugs, a better understanding of myeloma biology and clonal heterogeneity, and an improved management of toxicities. The choice of regimen at relapse is usually based on prior response, toxicities, age and comorbidities of relapsed patients. Areas covered: A review was performed of the most recent and effective therapeutic strategies for the relapsed myeloma setting, by documenting the latest clinical evidence from phase II and III clinical trials. Of note, new drugs, such as carfilzomib, ixazomib, pomalidomide, daratumumab and elotuzumab, alone or in combinations in doublet or triplet regimens, have greatly increased the treatment armamentarium against myeloma. Expert commentary: Impressive results have been obtained with new drugs in relapsed patients. Besides number of prior therapies and previous response, other factors play a crucial role in the selection of therapy. Re-challenge with previous drugs can be adopted if previous responses lasted at least 6 months and therapy had induced low toxicity. Patients' risk status can further help to appropriately select therapy at relapse, and clinical trials will allow physicians to use newer targeted therapies and immune-therapies, thus delaying palliative approaches to later relapse stages.

Use of depth of response to predict progression-free survival in relapsed or refractory multiple myeloma: Evaluation of results from 102 clinical trials

Progression-free survival (PFS) is the standard endpoint for demonstration of clinical effectiveness of novel therapies in relapsed or refractory multiple myeloma (RRMM). However, the long evaluation times for PFS limits its usefulness in the development of new therapies. Therefore, the objective of this analysis was to determine the relationship between response rates and median PFS in RRMM. A database was systematically developed from 268 identified RRMM trials reported from 1999 to 2016. Evaluated covariates for the relationship between response rates and PFS included age, sex, drug class(es), and number of drug classes. One-hundred two (102) trials involving 136 cohorts were included in the meta-analysis, representing 13 322 patients in total. Regression analysis using response rates and median PFS indicated that the correlation between very good partial response (VGPR) or better and median PFS was higher (R2  = 0.63) than the separately analyzed correlations between clinical benefit, overall response, or complete response rate and median PFS (R2  = 0.47 - 0.52). Subsequent covariate analysis revealed that treatment with an immunomodulatory imide drug (IMiD) further improved the relationship (R2  = 0.69), with a longer median PFS at a given VGPR or better rate when at least 1 drug treatment was an IMiD. Number of drug classes was not found to alter this relationship. In conclusion, VGPR or better rate can be used to predict the median PFS, with adjustment for the additional PFS provided by an IMiD.

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.