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

Direct P70S6K1 inhibition to replace dexamethasone in synergistic combination with MCL-1 inhibition in multiple myeloma

Novel combination therapies have markedly improved the lifespan of patients with multiple myeloma (MM), but drug resistance and disease relapse remain major clinical problems. Dexamethasone and other glucocorticoids are a cornerstone of conventional and new combination therapies for MM, although their use is accompanied by serious side effects. We aimed to uncover drug combinations that act in synergy and, as such, allow reduced dosing while remaining effective. Dexamethasone and the myeloid cell leukemia 1 (MCL-1) inhibitor S63845 (MCL-1i) proved the most potent combination in our lethality screen and induced apoptosis of human myeloma cell lines (HMCLs) that was 50% higher compared with an additive drug effect. Kinome analysis of dexamethasone-treated HMCLs revealed a reduction in serine/threonine peptide phosphorylation, which was predicted to result from reduced Akt activity. Biochemical techniques showed no dexamethasone-induced effects on FOXO protein or GSK3 but did show a 50% reduction in P70S6K phosphorylation, downstream of the Akt-mTORC1 axis. Replacing dexamethasone by the P70S6K1 isoform-specific inhibitor PF-4708671 (S6K1i) revealed similar and statistically significant synergistic apoptosis of HMCLs in combination with MCL-1i. Interestingly, apoptosis induced by the P70S6K1i and MCL-1i combination was more-than-additive in all 9 primary MM samples tested; this effect was observed for 6 of 9 samples with the dexamethasone and MCL-1i combination. Toxicity on stem and progenitor cell subsets remained minimal. Combined, our results show a strong rationale for combination treatments using the P70S6K inhibitor in MM. Direct and specific inhibition of P70S6K may also provide a solution for patients ineligible or insensitive to dexamethasone or other glucocorticoids.

KarMMa-RW: comparison of idecabtagene vicleucel with real-world outcomes in relapsed and refractory multiple myeloma

Patients with relapsed and refractory multiple myeloma (RRMM) who are triple-class exposed (to an immunomodulatory agent, proteasome inhibitor, and anti-CD38 antibody) have limited treatment options and there is no standard of care. Idecabtagene vicleucel (ide-cel, bb2121), a BCMA-directed CAR T-cell therapy, demonstrated efficacy in triple-class exposed RRMM patients in the KarMMa trial (NCT03361748). In this retrospective study (KarMMa-RW), patient-level data from triple-class exposed RRMM patients were merged into a single data model and compared with KarMMa using trimmed stabilized inverse probability of treatment weighting. Endpoints included overall response rate (ORR; primary), rate of very good partial response or better (≥VGPR), progression-free survival (PFS), and overall survival (OS). Of 1949 real-world triple-class exposed RRMM patients, 190 received subsequent (index) line of therapy and met KarMMa eligibility criteria (Eligible RRMM cohort). With a median follow-up of 13.3 months in KarMMa and 10.2 months in Eligible RRMM, ORR, and ≥VGPR were significantly improved in KarMMa versus Eligible RRMM (ORR, 76.4% vs 32.2%; ≥VGPR, 57.9% vs 13.7%; both P < 0.0001) as were PFS (11.6 vs 3.5 months; P = 0.0004) and OS (20.2 vs 14.7 months; P = 0.0006). This study demonstrated that ide-cel significantly improved responses and survival compared with currently available therapies in triple-class exposed RRMM.

Effect of prior treatments on selinexor, bortezomib, and dexamethasone in previously treated multiple myeloma

Therapeutic regimens for previously treated multiple myeloma (MM) may not provide prolonged disease control and are often complicated by significant adverse events, including peripheral neuropathy. In patients with previously treated MM in the Phase 3 BOSTON study, once weekly selinexor, once weekly bortezomib, and 40 mg dexamethasone (XVd) demonstrated a significantly longer median progression-free survival (PFS), higher response rates, deeper responses, a trend to improved survival, and reduced incidence and severity of bortezomib-induced peripheral neuropathy when compared with standard twice weekly bortezomib and 80 mg dexamethasone (Vd). The pre-specified analyses described here evaluated the influence of the number of prior lines of therapy, prior treatment with lenalidomide, prior proteasome inhibitor (PI) therapy, prior immunomodulatory drug therapy, and prior autologous stem cell transplant (ASCT) on the efficacy and safety of XVd compared with Vd. In this 1:1 randomized study, enrolled patients were assigned to receive once weekly oral selinexor (100 mg) with once weekly subcutaneous bortezomib (1.3 mg/m2) and 40 mg per week dexamethasone (XVd) versus standard twice weekly bortezomib and 80 mg per week dexamethasone (Vd). XVd significantly improved PFS, overall response rate, time-to-next-treatment, and showed reduced all grade and grade ≥ 2 peripheral neuropathy compared with Vd regardless of prior treatments, but the benefits of XVd over Vd were more pronounced in patients treated earlier in their disease course who had either received only one prior therapy, had never been treated with a PI, or had prior ASCT. Treatment with XVd improved outcomes as compared to Vd regardless of prior therapies as well as manageable and generally reversible adverse events. XVd was associated with clinical benefit and reduced peripheral neuropathy compared to standard Vd in previously treated MM. These results suggest that the once weekly XVd regimen may be optimally administered to patients earlier in their course of disease, as their first bortezomib-containing regimen, and in those relapsing after ASCT.Trial registration: ClinicalTrials.gov (NCT03110562). Registered 12 April 2017. https://clinicaltrials.gov/ct2/show/NCT03110562 .

The role of CD38 in HIV infection

The widely-expressed molecule CD38 is a single-stranded type II transmembrane glycoprotein that is mainly involved in regulating the differentiation and activation state of the cell. CD38 has broad and complex functions, including enzymatic activity, intercellular signal transduction, cell activation, cytokine production, receptor function and adhesion activity, and it plays an important role in the physiological and pathological processes of many diseases. Many studies have shown that CD38 is related to the occurrence and development of HIV infection, and CD38 may regulate its progression through different mechanisms. Therefore, investigating the role of CD38 in HIV infection and the potential signaling pathways that are involved may provide a new perspective on potential treatments for HIV infection. In the present review, the current understanding of the roles CD38 plays in HIV infection are summarized. In addition, the specific role of CD38 in the process of HIV infection of human CD4⁺ T lymphocytes is also discussed.

Emerging Therapeutic Strategies to Overcome Drug Resistance in Multiple Myeloma

Simple Summary

Multiple myeloma is a deadly blood cancer, but fortunately drug development has substantially prolonged the lifespan of patients to average more than a decade after diagnosis with optimal therapy. As a result, the population of patients living with multiple myeloma has grown considerably. Through its course, patients suffer repeated relapses for which they require new lines of treatment. Currently, the key drug classes for treatment are immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies. The goal of this review is to summarize the understanding of the problem of resistance to these drugs, which is ultimately responsible for patient fatality. In addition, we will focus on how new agents that are promising in clinical trials overcome resistance.

Abstract

Multiple myeloma is a malignant plasma cell neoplasm that remains incurable and is ultimately fatal when patients acquire multi-drug resistance. Thus, advancing our understanding of the mechanisms behind drug resistance in multi-relapsed patients is critical for developing better strategies to extend their lifespan. Here, we review the understanding of resistance to the three key drug classes approved for multiple myeloma treatment: immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies. We consider how the complex, heterogenous biology of multiple myeloma may influence the acquisition of drug resistance and reflect on the gaps in knowledge where additional research is needed to improve our treatment approaches. Fortunately, many agents are currently being evaluated preclinically and in clinical trials that have the potential to overcome or delay drug resistance, including next-generation immunomodulatory drugs and proteasome inhibitors, novel small molecule drugs, chimeric antigen receptor T cells, antibody-drug conjugates, and bispecific antibodies. For each class, we discuss the potential of these strategies to overcome resistance through modifying agents within each class or new classes without cross-resistance to currently available drugs.

Management of patients with difficult-to-treat multiple myeloma

Newer treatments for multiple myeloma (MM) have improved response rates and survival for many patients. However, MM remains challenging to treat due to the propensity for multiple relapses, cumulative and emergent toxicities from prior therapies and increasing genomic complexity that arises due to clonal evolution. In particular, patients with relapsed/refractory MM often require increased complexity of treatment, yet still experience poorer outcomes compared with patients who are newly diagnosed. Additionally, several patient subgroups, including those with extramedullary disease and patients who are frail and/or have multiple comorbidities, have an unfavorable prognosis and remain undertreated. This review (based on an Updates-in-Hematology session at the 25th European Hematology Association Annual Congress 2020) discusses the management of these difficult-to-treat patients with MM.

Belantamab mafodotin in combination with novel agents in relapsed/refractory multiple myeloma: DREAMM-5 study design

Belantamab mafodotin (belamaf) is a BCMA-targeted antibody-drug conjugate recently approved as monotherapy for adults with relapsed/refractory multiple myeloma who have received ≥4 prior therapies. Belamaf binds to BCMA and eliminates myeloma cells by multimodal mechanisms of action. The cytotoxic and potential immunomodulatory properties of belamaf have led to novel combination studies with other anticancer therapies. Here, we describe the rationale and design of DREAMM-5, an ongoing Phase I/II platform study evaluating the safety and efficacy of belamaf combined with novel agents, including GSK3174998 (OX40 agonist), feladilimab (an ICOS; GSK3359609), nirogacestat (a gamma-secretase inhibitor; PF-03084014) and dostarlimab (a PD-1 blocker) versus belamaf monotherapy for patients with relapsed/refractory multiple myeloma. Clinical trial registration: NCT04126200 (ClinicalTrials.gov).

Understanding the Role of T-Cells in the Antimyeloma Effect of Immunomodulatory Drugs

Immunomodulatory drugs (IMiDs) are effective treatments for patients with multiple myeloma. IMiDs have pleotropic effects including targeting the myeloma cells directly, and improving the anti-myeloma immune response. In the absence of myeloma cells, lenalidomide and pomalidomide induce CD4⁺ T cell secretion of IL-2 and indirect activation of Natural Killer (NK) cells. In the context of T cell receptor ligation, IMiDs enhance T cell proliferation, cytokine release and Th1 responses, both in vivo and in vitro. Furthermore, combination treatment of IMiDs and myeloma-targeting monoclonal antibodies eg. daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7), checkpoint inhibitors, or bispecific T cell engagers showed synergistic effects, mainly via enhanced T and NK cell dependent cellular toxicity and T cell proliferation. Conversely, the corticosteroid dexamethasone can impair the immune modulatory effects of IMiDs, indicating that careful choice of myeloma drugs in combination with IMiDs is key for the best anti-myeloma therapeutic efficacy. This review presents an overview of the role for T cells in the overall anti-myeloma effects of immunomodulatory drugs.

A phase I study of anti-BCMA CAR T cell therapy in relapsed/refractory multiple myeloma and plasma cell leukemia

BACKGROUND

Relapsed/refractory (R/R) multiple myeloma (MM) patients and primary plasma cell leukemia (PCL) have an unfavorable prognosis and no effective treatment. This study was designed to assess the safety and preliminary efficacy of a novel anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T cell in R/R MM and PCL.

METHODS

Between February 22, 2017, and June 25, 2018, 28 R/R and two R/R primary PCL patients received a median dose of 11.2 × 106 CAR+ cells/kg. The subjects were refractory to a proteasome inhibitor and/or an immunomodulatory agent. Fludarabine and cyclophosphamide were given as lymphodepletion chemotherapy.

RESULTS

Results for these 30 consecutive patients who received an anti-BCMA CAR T cell infusion are reported. The patients had received a median of four prior lines of therapy. A total of 44 different types of adverse events were recorded, and hematologic toxic effects were the most common events of any grade during treatment. Hematologic toxic effects were also the most common events of grade 3 or higher. A total of 29 patients (96.7%) had cytokine release syndrome, which was of grade 1 or 2 in 24 patients (80%) and grade 3 in five patients (16.7%). Neurologic toxic effects only occurred in one patient (3.3%) and were of grade 1. The objective response rate was 90%, and the complete response rate was 43.3%. With a median follow-up of 12.6 months, the median progression-free survival (PFS) and overall survival were 5.2 months and 14.0 months. One of the two primary PCL achieved a complete response with a PFS of 307 days. The other patients achieved a very good partial response with a PFS of 117 days.

CONCLUSIONS

Anti-BCMA CAR T cell treatment is safe and highly active in R/R 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.).

Identification of resistance pathways and therapeutic targets in relapsed multiple myeloma patients through single-cell sequencing

Multiple myeloma (MM) is a neoplastic plasma-cell disorder characterized by clonal proliferation of malignant plasma cells. Despite extensive research, disease heterogeneity within and between treatment-resistant patients is poorly characterized. In the present study, we conduct a prospective, multicenter, single-arm clinical trial (NCT04065789), combined with longitudinal single-cell RNA-sequencing (scRNA-seq) to study the molecular dynamics of MM resistance mechanisms. Newly diagnosed MM patients (41), who either failed to respond or experienced early relapse after a bortezomib-containing induction regimen, were enrolled to evaluate the safety and efficacy of a daratumumab, carfilzomib, lenalidomide and dexamethasone combination. The primary clinical endpoint was safety and tolerability. Secondary endpoints included overall response rate, progression-free survival and overall survival. Treatment was safe and well tolerated; deep and durable responses were achieved. In prespecified exploratory analyses, comparison of 41 primary refractory and early relapsed patients, with 11 healthy subjects and 15 newly diagnosed MM patients, revealed new MM molecular pathways of resistance, including hypoxia tolerance, protein folding and mitochondria respiration, which generalized to larger clinical cohorts (CoMMpass). We found peptidylprolyl isomerase A (PPIA), a central enzyme in the protein-folding response pathway, as a potential new target for resistant MM. CRISPR-Cas9 deletion of PPIA or inhibition of PPIA with a small molecule inhibitor (ciclosporin) significantly sensitizes MM tumor cells to proteasome inhibitors. Together, our study defines a roadmap for integrating scRNA-seq in clinical trials, identifies a signature of highly resistant MM patients and discovers PPIA as a potent therapeutic target for these tumors.

CAR-T Therapy, the End of a Chapter or the Beginning of a New One?

Simple Summary

CAR-T therapy is a breakthrough treatment in our fight against cancer. It was recently approved for the treatment of advanced diffuse large B-cell lymphoma and acute lymphoblastic leukaemia after the failure of previous multiple therapies. The positive results achieved in the registration studies for those patients were remarkable. Unfortunately, this was not the end of this chapter. Disease relapses occur in the range of 30–60% of patients treated with CAR-T therapy. Cytokine release syndrome represents a major side effect for treatment with CAR-T therapy. Notwithstanding, the high positive results triggered the start of a huge research activity of CAR-T therapy in other haematologic malignancies such as acute myelogenous leukaemia, Hodgkin’s disease, chronic lymphocytic leukaemia, and multiple myeloma. The research is also trying to overcome the hurdles stated above. These activities represent a new chapter in the management of haematologic malignancies with CAR-T therapy.

Abstract

Chimeric antigen receptor-T (CAR-T) therapy targeting CD19 has revolutionised the treatment of advanced acute lymphoblastic leukaemia (ALL) and diffuse large B-cell lymphoma (DLBCL). The ability to specifically target the cancer cells has shown high positive results as reported in the registration studies. The success of CAR-T therapy in the first two indications led to the initiation of a large number of studies testing CAR-T therapy in different haematologic tumours such as acute myelogenous leukaemia (AML), Hodgkin’s disease (HD), chronic lymphocytic leukaemia (CLL), multiple myeloma (MM), as well as different solid tumours. Unfortunately, relapses occurred in patients treated with CAR-T therapy, calling for the development of effective subsequent therapies. Likewise, this novel mechanism of action was also accompanied by a different toxicity profile, such as cytokine release syndrome (CRS). Patients’ access to the treatment is still limited by its cost. Notwithstanding, this did not prohibit further development of this new therapy to treat other malignancies. This research activity of CAR-T therapy moves it from being used as an end-stage treatment for ALL and DLBCL to a new therapeutic option for a wide range of patients with different haematologic and solid tumours.

Real-World Outcome in the pre-CAR-T Era of Myeloma Patients Qualifying for CAR-T Cell Therapy

Background

CAR-T cell therapy is likely to be introduced starting from 2021 in patients with relapsed/refractory myeloma (r/r MM) in Europe. In order to qualify for commercial CAR-T treatment, it is assumed that r/r MM patients will have to be exposed to at least three lines of previous treatments including lenalidomide, bortezomib and anti-CD38 treatment. However, the outcome of this particular subgroup of r/r MM patients is largely unknown whereas this knowledge is crucial to estimate the possible benefit of eventual CAR-T treatment.

Methods

In this non-interventional, retrospective single-center study, we analyzed all subsequent r/r MM patients treated between 01/2016 (when anti-CD38 treatment was commercially introduced in Switzerland) and 04/2020 at the University Hospital of Bern. Patients were eligible for the study if they had received at least three lines of treatment including one proteasome inhibitor (PI), one immunomodulatory drug (IMID) and one anti-CD38 antibody, and if they were in need of subsequent treatment and effectively received further lines of treatment.

Results

Among 56 patients fulfilling the criteria of at least three lines of treatment including PI, IMID and anti-CD38 treatment, only 34 (60%) effectively received subsequent further therapy. This suggests that 40% of r/r MM patients never receive additional treatment after at least three lines of treatment including PI, IMID and anti-CD38 treatment. For patients receiving further treatment, the median number of previous lines of treatment was 4.5 (range 2–12), including autologous stem cell transplantation in 31 (91%) patients. 13 (37%) patients were penta-refractory. The most frequently used treatment options were IMID/dexamethasone treatment in 11 (32%) patients, followed by PI/dexamethasone in 10 (29%) patients. 21 (62%) patients received two or more additional lines of therapy. The median PFS was 6.6 months (range 0–36.6 months), the median TTNT was 7.5 months (range 1.4–24.5 months) and the median OS was 13.5 months, (range 0.1–38 months) for the first subsequent treatment. The overall response rate (ORR) to the first subsequent treatment was 41%, with a median duration of the response of 5 months (range 1–37 months). 12% of the patients achieved VGPR or better, with a median duration of response of 8 months (range 3–37 months).

Conclusions

Myeloma patients refractory after at least three lines of anti-CD38/PI/IMID treatment have a poor prognosis with a PFS of 6.6 months and OS of 13.5 months. These data may serve as reference to compare the potential benefit of CAR-T treatment in this group of myeloma patients when available in the near future.

CD138- multiple myeloma cells express high level of CHK1 which correlated to overall survival in MM patient

Multiple myeloma (MM) is a disease in which abnormal plasma cells proliferate and secrete monoclonal immunoglobulin in the bone marrow. The main characteristic of plasma cells is the expression of the cell surface antigen syndecan-1 (CD138). However, the expression of CD138 is limited to terminally differentiated plasma cells during B cell development. A small subpopulation (2~5%) of human MM cells that lack CD138 expression has been shown to possess enormous proliferation potential in vitro experiment and in animal models, and they also can differentiate into CD138⁺ plasma cells. Thus, this small subset of MM cells was regarded as myeloma cancer stem cell (MCSC). However, its characteristics associated with the pathogenesis of MM remain unclear. In this study, we analyzed the gene expression data of CD138 cell lines downloaded from Gene Expression Omnibus (GEO) database. Limma package in RStudio was used to identify differentially expressed genes (DEGs). Genes enrichment and protein-protein interaction (PPI) network analysis were performed on DAVID and STRING databases. Furthermore, overall survival (OS) analysis in MM patient was utilized to screen out the hub-genes closely associate with the MM pathogenesis process. Hub-genes expression validation and receiver operating characteristic curve (ROC) analysis was performed in different stages of plasma cell disorder diseases. Finally, we verified these findings in MM patient samples. Through integrated bioinformatics analysis of MM CD138^- and CD138⁺ cell lines, we found that CDC7, CDK1, and CHK1 are highly expressed in CD138^- MM cells. These genes are crucial in the G2/M phase of the cell cycle pathway, which is closely related to the malignant proliferation in various tumor cells. Of note, we found that patients with high expression of CDC7, CDK1, and CHK1 had shorter overall survival time. The expression of CHK1 was significantly increased in MM cells compared with normal plasma cell (NPC) and MGUS. More importantly, we further clarified that the expression of CHK1 in release/refraction MM (R/R MM) has obviously increased compared with new diagnosed MM (ND MM).

Efficacy and safety of weekly carfilzomib (70 mg/m2), dexamethasone, and daratumumab (KdD70) is comparable to twice-weekly KdD56 while being a more convenient dosing option: a cross-study comparison of the CANDOR and EQUULEUS studies

The regimen of carfilzomib, daratumumab, and dexamethasone (KdD) shows activity in patients with relapsed/refractory multiple myeloma. KdD at the twice-weekly 56 mg/m² carfilzomib dose (KdD56) was used in the randomized phase 3 CANDOR study (NCT03158688), whereas KdD at the once-weekly 70 mg/m² carfilzomib dose (KdD70) was used in the phase 1 b EQUULEUS study (NCT01998971). We analyzed efficacy data from comparable CANDOR and EQUULEUS patients using inverse probability of treatment weighting (IPTW)-adjusted models. These weights were calculated from propensity scores derived to balance prespecified baseline covariates. The side-by-side and adjusted comparisons showed similar efficacy for overall response rates and progression-free survival in the two groups, with a series of sensitivity analyses showing consistent findings. Safety data were generally consistent with the known safety profiles of each individual drug. Once-weekly KdD70 is comparable to twice-weekly KdD56 in terms of efficacy and safety while being a more convenient dosing option.

Monoclonal antibody utilization characteristics in patients with multiple myeloma

This study analyzed 91 multiple myeloma patients who received two monoclonal antibodies, Daratumumab and Elotuzumab, over a year and report the adverse event profile, infusion practices and utilization of these drugs in the real world. All current reported data on monoclonal antibodies is from clinical trials, without any real-world experience. Patients from Mayo Clinic Florida or Arizona diagnosed with relapsed or refractory multiple myeloma who were treated with Daratumumab or Elotuzumab alone or in combination between 1 January 2016 and 31 December 2016 were included in the analysis. Daratumumab-treated patients (n = 78) were more heavily pre-treated than that in published clinical trials, whereas the elotuzumab patient (n = 13) profile was similar to that published before. Infusion time was on average 2 hours less than the prescribing guidelines and premedication use varied noticeably after the initial monoclonal antibody infusion, with an overall decrease over time. We noted higher than reported haematologic adverse events, especially neutropenia and fewer non-haematologic adverse events. 91.7% infusion-related reactions were observed during the first monoclonal antibody infusion, with a subsequent decrease. All infusion-related reactions were grade 2 or less, and none of the patients discontinued treatment due to infusion-related reactions. Baseline allergy profile or laboratory tests were not associated with the likelihood of developing monoclonal antibody-related infusion-related reactions. The real-world safety profile of monoclonal antibodies showed varying adverse event patterns than those reported in previous clinical trials. The infusion-related reaction patterns were similar to previous reports. Despite changes in premedication regimens safety was maintained in succeeding infusions. Such treatment utilization data is vital to broaden our knowledge of approved therapeutic agents and maximize their benefits for patients.

Multiple myeloma with 1q21 amplification is highly sensitive to MCL-1 targeting

Prosurvival BCL-2 family proteins are potent inhibitors of apoptosis and often overexpressed in lymphoid malignancies. In multiple myeloma (MM), MCL-1 expression contributes to survival of malignant plasma cells, and overexpression correlates with poor prognosis. In this study, we investigated whether sensitivity to the novel MCL-1 inhibitor S63845 could be predicted using cytogenetics, focusing on amplification of 1q21, the chromosomal region that contains the MCL1 locus. In addition, we studied the relation of MCL-1 inhibitor sensitivity with other diagnostic characteristics and BCL-2 family protein expression. In 31 human myeloma cell lines and in bone marrow aspirates from 47 newly diagnosed MM patients, we measured the effect of S63845 alone, or combined with BCL-2 inhibitor ABT-199 (venetoclax), and BCL-XL inhibitor A-1155463 or A-1331852 on cell viability. We demonstrated for the first time that MM cells from patients with 1q21 amplification are significantly more sensitive to inhibition of MCL-1. We suggest that this increased sensitivity results from high relative MCL1 expression resulting from amplification of 1q21. Additionally, and partially independent from 1q21 status, high serum β2 microglobulin level and presence of renal insufficiency correlated with increased sensitivity to MCL-1 inhibitor treatment. Combining S63845 with other BH3 mimetics synergistically enhanced apoptosis compared with single inhibitors, and sensitivity to inhibitor combinations was found in a large proportion of MM insensitive to MCL-1 inhibition alone. Collectively, our data indicate that amplification of 1q21 identifies an MM subset highly sensitive to MCL-1 inhibitor treatment and can be used as a predictive marker to guide selection of therapy.

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.

Emergence of overt myeloma in a patient with chronic lymphocytic leukemia on ibrutinib therapy

Ibrutinib is approved for chronic lymphocytic leukemia (CLL). However, its role in the treatment of multiple myeloma (MM) is not clear and is under investigation. We report a case of CLL that developed MM while on therapy with ibrutinib indicating that this drug may not be active against MM.

Carfilzomib, dexamethasone, and daratumumab versus carfilzomib and dexamethasone for patients with relapsed or refractory multiple myeloma (CANDOR): results from a randomised, multicentre, open-label, phase 3 study

BACKGROUND

Lenalidomide and bortezomib frontline exposure has raised a growing need for novel treatments for patients with relapsed or refractory multiple myeloma. Carfilzomib in combination with daratumumab has shown substantial efficacy with tolerable safety in relapsed or refractory multiple myeloma in a phase 1 study. In this study, we aimed to compare the efficacy and safety of carfilzomib, dexamethasone, and daratumumab versus carfilzomib and dexamethasone in patients with relapsed or refractory multiple myeloma.

METHODS

In this randomised, multicentre, open-label, phase 3 study, 466 patients recruited from 102 sites across North America, Europe, Australia, and Asia with relapsed or refractory multiple myeloma were randomly assigned 2:1 to carfilzomib, dexamethasone, and daratumumab (KdD) or carfilzomib and dexamethasone (Kd). All patients received twice per week carfilzomib at 56 mg/m² (20 mg/m²; days 1 and 2 during cycle 1). Daratumumab (8 mg/kg) was administered intravenously on days 1 and 2 of cycle 1 and at 16 mg/kg weekly for the remaining doses of the first two cycles, then every 2 weeks for four cycles (cycles 3-6), and every 4 weeks thereafter. Patients received 40 mg dexamethasone weekly (20 mg for patients ≥75 years old starting on the second week). The primary endpoint was progression-free survival assessed by intention to treat. Adverse events were assessed in the safety population. This trial (NCT03158688) is registered with ClinicalTrials.gov, and is active but not recruiting.

FINDINGS

Between June 13, 2017, and June 25, 2018, 466 patients of 569 assessed for eligibility were enrolled. After median follow-up of approximately 17 months, median progression-free survival was not reached in the KdD group versus 15·8 months in the Kd group (hazard ratio 0·63; 95% CI 0·46-0·85; p=0·0027). Median treatment duration was longer in the KdD versus the Kd group (70·1 vs 40·3 weeks). Grade 3 or higher adverse events were reported in 253 (82%) patients in the KdD group and 113 (74%) patients in the Kd group. The frequency of adverse events leading to treatment discontinuation was similar in both groups (KdD, 69 [22%]; Kd, 38 [25%]).

INTERPRETATION

KdD significantly prolonged progression-free survival versus Kd in patients with relapsed or refractory multiple myeloma and was associated with a favourable benefit-risk profile.

FUNDING

Amgen.

Efficacy of daratumumab combination regimen in patients with multiple myeloma: A combined analysis of phase III randomized controlled trials

The use of the CD38 monoclonal antibody daratumumab in combination with standard myeloma chemotherapy regimens has been studied extensively in recent years. We undertook an updated meta-analysis of phase III randomized controlled trials (RCT) to determine the efficacy of daratumumab combination regimens. The relative risk for progression was significantly lower in daratumumab-treated cohorts (HR 0.46, 95% CI 0.38-0.55) and this was consistent across newly diagnosed and relapsed cases. No statistically significant improvement was identified in newly diagnosed patients with high-risk cytogenetics and this group remains a therapeutic challenge.

Randomized, placebo-controlled, phase 3 study of perifosine combined with bortezomib and dexamethasone in patients with relapsed, refractory multiple myeloma previously treated with bortezomib

Perifosine, an investigational, oral, synthetic alkylphospholipid, inhibits signal transduction pathways of relevance in multiple myeloma (MM) including PI3K/Akt. Perifosine demonstrated anti-MM activity in preclinical studies and encouraging early-phase clinical activity in combination with bortezomib. A randomized, double-blind, placebo-controlled phase 3 study was conducted to evaluate addition of perifosine to bortezomib-dexamethasone in MM patients with one to four prior therapies who had relapsed following previous bortezomib-based therapy. The primary endpoint was progression-free survival (PFS). The study was discontinued at planned interim analysis, with 135 patients enrolled. Median PFS was 22.7 weeks (95% confidence interval 16·0-45·4) in the perifosine arm and 39.0 weeks (18.3-50.1) in the placebo arm (hazard ratio 1.269 [0.817-1.969]; P = .287); overall response rates were 20% and 27%, respectively. Conversely, median overall survival (OS) was 141.9 weeks and 83.3 weeks (hazard ratio 0.734 [0.380-1.419]; P = .356). Overall, 61% and 55% of patients in the perifosine and placebo arms reported grade 3/4 adverse events, including thrombocytopenia (26% vs 14%), anemia (7% vs 8%), hyponatremia (6% vs 8%), and pneumonia (9% vs 3%). These findings demonstrate no PFS benefit from the addition of perifosine to bortezomib-dexamethasone in this study of relapsed/refractory MM, but comparable safety and OS.

Checkpoint Inhibitors and Engineered Cells: New Weapons for Natural Killer Cell Arsenal Against Hematological Malignancies

Natural killer (NK) cells represent one of the first lines of defense against malignant cells. NK cell activation and recognition are regulated by a balance between activating and inhibitory receptors, whose specific ligands can be upregulated on tumor cells surface and tumor microenvironment (TME). Hematological malignancies set up an extensive network of suppressive factors with the purpose to induce NK cell dysfunction and impaired immune-surveillance ability. Over the years, several strategies have been developed to enhance NK cells-mediated anti-tumor killing, while other approaches have arisen to restore the NK cell recognition impaired by tumor cells and other cellular components of the TME. In this review, we summarize and discuss the strategies applied in hematological malignanciesto block the immune check-points and trigger NK cells anti-tumor effects through engineered chimeric antigen receptors.

Role of the Bone Marrow Milieu in Multiple Myeloma Progression and Therapeutic Resistance

Multiple myeloma (MM) is a cancer of the plasma cells within the bone marrow (BM). Studies have shown that the cellular and noncellular components of the BM milieu, such as cytokines and exosomes, play an integral role in MM pathogenesis and progression by mediating drug resistance and inducing MM proliferation. Moreover, the BM microenvironment of patients with MM facilitates cancer tolerance and immune evasion through the expansion of regulatory immune cells, inhibition of antitumor effector cells, and disruption of the antigen presentation machinery. These are of special relevance, especially in the current era of cancer immunotherapy. An improved understanding of the supportive role of the MM BM microenvironment will allow for the development of future therapies targeting MM in the context of the BM milieu to elicit deeper and more durable responses. In the present review, we have discussed our current understanding of the role of the BM microenvironment in MM progression and resistance to therapy and discuss novel potential approaches to alter its pro-MM function.

Hspa13 Promotes Plasma Cell Production and Antibody Secretion

The generation of large numbers of plasma cells (PCs) is a main factor in systemic lupus erythematosus (SLE). We hypothesize that Hspa13, a member of the heat shock protein family, plays a critical role in the control of PC differentiation. To test the hypothesis, we used lipopolysaccharide (LPS)-activated B cells and a newly established mouse line with a CD19^cre-mediated, B cell–specific deletion of Hspa13: Hspa13 cKO mice. We found that Hspa13 mRNA was increased in PCs from atacicept-treated lupus-prone mice and in LPS-stimulated plasmablasts (PBs) and PCs. A critical finding was that PBs and PCs [but not naïve B cells and germinal center (GC) B cells] expressed high levels of Hspa13. In contrast, the Hspa13 cKO mice had a reduction in BPs, PCs, and antibodies induced in vitro by LPS and in vivo by sheep red blood cells (SRCs)- or 4-hydroxy-3-nitrophenylacetyl (NP)-immunization. Accordingly, the Hspa13 cKO mice had reduced class-switched and somatically hypermutated antibodies with defective affinity maturation. Our work also showed that Hspa13 interacts with proteins (e.g., Bcap31) in the endoplasmic reticulum (ER) to positively regulate protein transport from the ER to the cytosol. Importantly, Hspa13 mRNA was increased in B220⁺ cells from patients with multiple myeloma (MM) or SLE, whereas Hspa13 cKO led to reduced autoantibodies and proteinuria in both pristane-induced lupus and lupus-prone MRL/lpr mouse models. Collectively, our data suggest that Hspa13 is critical for PC development and may be a new target for eliminating pathologic PCs.

Discovery of CRBN E3 Ligase Modulator CC-92480 for the Treatment of Relapsed and Refractory Multiple Myeloma

Many patients with multiple myeloma (MM) initially respond to treatment with modern combination regimens including immunomodulatory agents (lenalidomide and pomalidomide) and proteasome inhibitors. However, some patients lack an initial response to therapy (i.e., are refractory), and although the mean survival of MM patients has more than doubled in recent years, most patients will eventually relapse. To address this need, we explored the potential of novel cereblon E3 ligase modulators (CELMoDs) for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). We found that optimization beyond potency of degradation, including degradation efficiency and kinetics, could provide efficacy in a lenalidomide-resistant setting. Guided by both phenotypic and protein degradation data, we describe a series of CELMoDs for the treatment of RRMM, culminating in the discovery of CC-92480, a novel protein degrader and the first CELMoD to enter clinical development that was specifically designed for efficient and rapid protein degradation kinetics.

MOR202, a novel anti-CD38 monoclonal antibody, in patients with relapsed or refractory multiple myeloma: a first-in-human, multicentre, phase 1-2a trial

BACKGROUND

Treatment of multiple myeloma is not curative, but targeting CD38 improves patient survival. To further explore this therapeutic approach, we investigated the safety and activity of MOR202, a novel monoclonal antibody targeting CD38, in patients with multiple myeloma.

METHODS

This is a multicentre, open-label, phase 1-2a trial done at ten hospitals in Germany and Austria. Enrolled patients were aged 18 years or older with relapsed or refractory multiple myeloma and Karnofsky performance status of 60% or higher. Patients were assigned to the different treatment regimens with MOR202 ranging between 0·01 mg/kg and 16 mg/kg in a 3 + 3 design. Dose-escalation and expansion was done either with MOR202 intravenous infusions alone (MOR202 q2w [twice a week] and q1w [weekly] groups) or in combination with dexamethasone (MOR202 with dexamethasone group), with dexamethasone plus pomalidomide (MOR202 with dexamethasone plus pomalidomide group) or plus lenalidomide (MOR202 with dexamethasone plus lenalidomide group). Primary endpoints were safety, MOR202 maximum tolerated dose (or recommended dose) and regimen, and immunogenicity. The primary analysis was assessed in the safety population, which included patients who received at least one dose of any study drug. This trial is registered with ClinicalTrials.gov, NCT01421186.

FINDINGS

Between Aug 24, 2011, and Aug 1, 2017, 91 patients were treated, 35 with MOR202 monotherapy, and 56 with MOR202 combination regimens (18 in the MOR202 with dexamethasone group, 21 in the MOR202 with dexamethasone plus pomalidomide group, and 17 in the MOR202 with dexamethasone plus lenalidomide group). MOR202 intravenous infusions were safely administered within 30 min. Infusion-related reactions occurred in 14 (40%) of 35 patients receiving MOR202 monotherapy without steroids, and in four (7%) of 56 patients receiving MOR202 combination treatment. MOR202 maximum tolerated dose was not reached and the recommended regimens were MOR202 administered as an intravenous infusion for 30 min at doses up to 16 mg/kg with dexamethasone (40 mg), or in combination with dexamethasone plus lenalidomide (25 mg) or pomalidomide (4 mg). 35 (38%) of 91 patients developed lymphopenia, 30 (33%) developed neutropenia, and 27 (30%) developed leukopenia; these were the most common grade 3 or higher treatment-emergent adverse events. Serious adverse events were reported in 51 (56%) of 91 patients. None of the deaths were associated with MOR202. One pomalidomide-associated death occurred in the MOR202 with dexamethasone plus pomalidomide group. No anti-MOR202 antibodies were detected in patients.

INTERPRETATION

MOR202 is safe and its clinical activity in patients with relapsed or refractory multiple myeloma is promising. Further clinical investigations of combinations with an immunomodulatory drug and dexamethasone are recommended.

FUNDING

MorphoSys AG.

A phase 2 study of ibrutinib in combination with bortezomib and dexamethasone in patients with relapsed/refractory multiple myeloma

Objective

We evaluated ibrutinib, a once‐daily inhibitor of Bruton's tyrosine kinase, combined with bortezomib and dexamethasone in patients with relapsed or relapsed/refractory multiple myeloma who had received 1‐3 prior therapies.

Methods

This was a phase 2, single‐arm, open‐label, multicentre study (NCT02902965). The primary endpoint was progression‐free survival (PFS).

Results

Seventy‐six patients were enrolled; 74 received ≥1 dose of study treatment. After median follow‐up of 19.6 months, median PFS was 8.5 months (95% CI: 6.2‐10.8); median overall survival was not reached. Overall response rate was 57% (95% CI: 45‐68), and median duration of response was 9.5 months (95% CI: 6.9‐10.6). Grade 3/4 AEs occurred in 73% of patients and fatal AEs occurred in 15% of patients. Incidence of major haemorrhage was 5%; one patient died from cerebral haemorrhage. After an observed increased incidence of serious (42%) and fatal (11%) infections, enrolment was suspended to implement risk‐minimisation measures. The safety profile was otherwise consistent with known safety profiles of the individual drugs.

Conclusion

Ibrutinib combined with bortezomib and dexamethasone elicited clinical responses. However, efficacy assessments conducted at potential restart of enrolment indicated that the targeted PFS could not be reached with additional patient enrolment, and the study was terminated.

Gossypol induces apoptosis of multiple myeloma cells through the JUN-JNK pathway

Multiple myeloma (MM) is one of the most common hematologic neoplastic diseases. Gossypol was once used as a male contraceptive but is considered a novel antitumor agent. This study aimed to reveal the gossypol-induced apoptosis mechanism and its hub genes. Gossypol-induced MM cell apoptosis is concentration- and time-dependent. Of a total of 532 differentially expressed genes, 273 genes were upregulated and 259 genes were downregulated in gossypol-treated MM cells. Through KEGG and WGCNA analyses, the apoptosis-associated module was identified, and JUN was identified as the hub gene. The expression of the JUN protein product c-Jun was downregulated in MM cell lines compared to that in normal plasma cells. High-risk MM patients had a lower expression of JUN. High-expression JUN group patients had a lower risk of death. JUN overexpression in MM cells induced potent cell death and growth inhibition by a caspase-dependent apoptotic mechanism. DR5 is one of the upstream receptors of the JNK pathway, and shRNA knockdown of DR5 can partially reverse gossypol-induced apoptosis. A total of 1017 genes were coexpressed with JUN in MM patients. These genes are mainly involved in other JNK-associated signaling pathways, such as the IL6, EGF and PDGF signaling pathways. In conclusion, JUN is identified as the hub gene in gossypol-induced apoptosis, and gossypol can activate caspase-dependent apoptosis through the JNK pathway by targeting c-Jun and other JNK-associated pathways. DR5 and IL6 are also involved in this mechanism.

Once-weekly (70 mg/m2 ) vs twice-weekly (56 mg/m2 ) dosing of carfilzomib in patients with relapsed or refractory multiple myeloma: A post hoc analysis of the ENDEAVOR, A.R.R.O.W., and CHAMPION-1 trials

Combination of carfilzomib with dexamethasone (Kd) is approved for use in relapsed and/or refractory multiple myeloma (RRMM), with carfilzomib administered twice weekly at 56 mg/m² (Kd56 BIW) or once weekly at 70 mg/m² (Kd70 QW). Post hoc cross‐trial comparisons were performed to compare efficacy and safety profiles of Kd70 QW vs Kd56 BIW dosing schedules using data from three trials of patients with RRMM: A.R.R.O.W., CHAMPION‐1, and ENDEAVOR. To select for comparable patient populations, side‐by‐side efficacy and safety comparisons were performed in subgroups of patients with 2‐3 prior lines of therapy who were not refractory to bortezomib. The overall response rate (ORR) was 69.9% (95% confidence interval [CI], 61.7‐77.2) for Kd70 QW and 72.4% (95% CI, 65.9‐78.2) for Kd56 BIW. Median progression‐free survival (PFS) was 12.1 months (95% CI, 8.4‐14.3) for Kd70 QW and 14.5 months (95% CI, 10.2—not evaluable) for Kd56 BIW. Frequency of grade ≥ 3 adverse events (AEs) was 67.6% for Kd70 QW and 85.3% for Kd56 BIW. Regression analyses (adjusting for prognostic factors) of all patients in the trials who received Kd70 QW vs Kd56 BIW estimated a PFS hazard ratio of 0.91 (95% CI, 0.69‐1.19; P = .47) and an ORR odds ratio of 1.12 (95% CI, 0.74‐1.69; P = .61). These results suggest that Kd70 QW has a comparable efficacy profile compared with Kd56 BIW and represents a convenient and well‐tolerated treatment for patients with RRMM.

Antibody therapies for multiple myeloma

Introduction: Multiple myeloma (MM) is characterized by the uncontrollable proliferation of plasma cells and the excessive production of a specific type of immunoglobulin. Immune system is deregulated in MM and, thus, immunotherapy is a promising therapeutic strategy.Areas covered: The first approach is to use monoclonal antibodies that recognize specific antigens on the surface of myeloma cells, such as CD38 and B-cell maturation antigen. Upon binding to their target, monoclonal antibodies activate the immune cells to destroy the malignant cell. Anti-CD38 molecules as part of highly effective combination regimens have been approved in both newly diagnosed and relapsed/refractory patients and have significantly changed the myeloma treatment landscape in the recent years. Another strategy is to use antibodies that bind both to a molecule on the surface of the myeloma cell and another molecule on the surface of a T-cell (bispecific antibodies). Consecutively, the T-cell comes close to and recognizes the myeloma cell. These have shown promising results in heavily pre-treated patients.Expert opinion: Antibody therapy has significantly enhanced the armamentarium against MM. Further research should focus on tailoring the combination regimens based on disease and patient characteristics in order to optimize the efficacy and safety.

Activity of TAS4464, a novel NEDD8 activating enzyme E1 inhibitor, against multiple myeloma via inactivation of nuclear factor κB pathways

The ubiquitin proteasome pathway is essential for the proliferation and survival of multiple myeloma (MM) cells. TAS4464, a novel highly potent inhibitor of NEDD8 activating enzyme, selectively inactivates cullin-RING ubiquitin E3 ligases, resulting in accumulation of their substrates. Here, we examined 14 MM cell lines treated with TAS4464. TAS4464 induced growth arrest and cell death in the MM cell lines even in the presence of bone marrow stromal cells. It also induced the accumulation of phospho-inhibitor of κBα and phospho-p100, impaired the activities of nuclear factor κB (NF-κB) transcription factors p65 and RelB, and decreased the expression of NF-κB target genes, suggesting that TAS4464 inhibits both the canonical and non-canonical NF-κB pathways. TAS4464 had similar effects in an in vivo human-MM xenograft mouse model in which it was also observed to have strong antitumor effects. TAS4464 synergistically enhanced the antitumor activities of the standard MM chemotherapies bortezomib, lenalidomide/dexamethasone, daratumumab and elotuzumab. Together, these results suggest that the anti-MM activity of TAS4464 occurs via inhibition of the NF-κB pathways, and that treatment with TAS4464 is a potential approach for treating MM by single and combination therapies.

Deregulated Expression of Long Non-coding RNA HOX Transcript Antisense RNA (HOTAIR) in Egyptian Patients with Multiple Myeloma

Increasing evidence of involvement of non-coding RNAs, especially long non-coding RNAs (lncRNAs), in the molecular biology of various malignancies have been recently reported. Their utilization as markers for diagnosis, prognosis and evaluation of treatment response was widely investigated. As the impact of lncRNA HOTAIR on multiple myeloma (MM) was not properly highlighted, we aimed to explore the expression levels of HOTAIR in three groups of MM patients and to analyze its relationship to different patients' characteristics. Plasma samples were withdrawn from 24 newly diagnosed MM patients, 23 post-therapy patients in complete response (CR) or very good partial response (VGPR) and 15 patients who had either progressive disease (PD) or relapse. The expression of lncRNA HOTAIR in MM patients and 20 healthy controls was analyzed by quantitative reverse transcription polymerase chain reactions. HOTAIR was significantly upregulated in newly diagnosed and PD/relapse categories in comparison with controls and MM patients who had achieved CR or VGPR (P < 0.001). Furthermore; HOTAIR expression levels correlated with the percentage of malignant plasma cells in bone marrow (P = 0.006) and disease stage (ISS stage) (P = 0.031). HOTAIR may be employed as  prognostic molecular marker and novel therapeutic tool for newly diagnosed MM patients.

Clinical Benefit of Long-Term Disease Control with Pomalidomide and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients

Background: We retrospectively analysed relapsed/refractory MM (RRMM) patients treated with pomalidomide and dexamethasone (PomaD) either in real life, or previously enrolled in an interventional (STRATUS, MM-010) or currently enrolled in an observational study (MM-015) to provide further insights on safety and tolerability and clinical efficacy. Methods: Between July 2013 and July 2018, 76 RRMM patients (including 33 double refractory MM) received pomalidomide 4 mg daily given orally on days 1–21 of each 28-day cycle, and dexamethasone 40 mg weekly (≤75 years) or 20 mg weekly for patients aged > 75 years. In nine patients a third agent was added to increase the response: Cyclophosphamide (in two fit patients) or clarithromycin (in seven frail patients). Patients received subcutaneous filgrastim as part of the prophylaxis regimen for neutropenia. Results: A median number of six (range 2–21) PomaD cycles were given. The regimen was well tolerated with grade 3–4 haematological and non-haematological adverse events in 39 (51%) and 25 (33%) patients, respectively. In patients who developed serious AE, pomalidomide dose reduction (11%, 14%) or definitive discontinuation (18%, 23%) were applied. All patients have been evaluated for response within the first two cycles. The disease control rate (DCR), i.e., those patients that had a response equal or better than stable disease (≥ SD), was high (89%), with 44% overall response rate (ORR) after six cycles. The achieved best responses were complete remission (CR, 5%), very good partial remission (VGPR, 4%), partial remission (PR, 35%), minimal response (MR, 7%), and stable disease (SD, 38%). After a median follow up of 19.6 months, median progression free survival was 9.4 months, and overall survival (OS) was 19.02 months. Univariate analysis showed that double refractory patients, or who received more than three previous lines had shorter PFS. At 18 months, regardless of the depth of response, patients with a disease control of at least six months, defined as maintenance of a best clinical and/or biochemical response to treatment for almost six months, had prolonged PFS (35.3% versus 20.6%, p = 0.0003) and OS (81.2% versus 15.9%, p < 0.0001) Conclusions: Our findings indicate that PomaD is a safe and well-tolerated regimen in real-life, associated with prolonged PFS and OS with acceptable toxicity. Moreover, Pd induced disease control in most intensively pre-treated patients and some of them achieved longer PFS than that obtained with the previous treatment.

Multiple myeloma exploits Jagged1 and Jagged2 to promote intrinsic and bone marrow-dependent drug resistance

Multiple myeloma is still incurable due to an intrinsic aggressiveness or, more frequently, to the interactions of malignant plasma cells with the bone marrow (BM) microenvironment. Myeloma cells educate BM cells to support neoplastic cell growth, survival, acquisition of drug resistance resulting in disease relapse. Myeloma microenvironment is characterized by Notch signaling hyperactivation due to the increased expression of Notch1 and 2 and the ligands Jagged1 and 2 in tumor cells. Notch activation influences myeloma cell biology and promotes the reprogramming of BM stromal cells. In this work we demonstrate, in vitro, ex vivo and by using a zebrafish multiple myeloma model, that Jagged inhibition causes a decrease in both myeloma-intrinsic and stromal cell-induced resistance to currently used drugs, i.e. bortezomib, lenalidomide and melphalan. The molecular mechanism of drug resistance involves the chemokine system CXCR4/SDF1α. Myeloma cell-derived Jagged ligands trigger Notch activity in BM stromal cells. These, in turn, secrete higher levels of SDF1α in the BM microenvironment increasing CXCR4 activation in myeloma cells, which is further potentiated by the concomitant increased expression of this receptor induced by Notch activation. Consistently with the augmented pharmacological resistance, SDF1α boosts the expression of BCL2, Survivin and ABCC1. These results indicate that a Jagged-tailored approach may contribute to disrupting the pharmacological resistance due to intrinsic myeloma cell features or to the pathological interplay with BM stromal cells and, conceivably, improve patients' response to standard-of-care therapies.

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.

Formononetin Regulates Multiple Oncogenic Signaling Cascades and Enhances Sensitivity to Bortezomib in a Multiple Myeloma Mouse Model

Here, we determined the anti-neoplastic actions of formononetin (FT) against multiple myeloma (MM) and elucidated its possible mode of action. It was observed that FT enhanced the apoptosis caused by bortezomib (Bor) and mitigated proliferation in MM cells, and these events are regulated by nuclear factor-κB (NF-κB), phosphatidylinositol 3-kinase (PI3K)/AKT, and activator protein-1 (AP-1) activation. We further noted that FT treatment reduced the levels of diverse tumorigenic proteins involved in myeloma progression and survival. Interestingly, we observed that FT also blocked persistent NF-κB, PI3K/AKT, and AP-1 activation in myeloma cells. FT suppressed the activation of these oncogenic cascades by affecting a number of signaling molecules involved in their cellular regulation. In addition, FT augmented tumor growth-inhibitory potential of Bor in MM preclinical mouse model. Thus, FT can be employed with proteasomal inhibitors for myeloma therapy by regulating the activation of diverse oncogenic transcription factors involved in myeloma growth.

Anti-BCMA CAR T-Cell Therapy bb2121 in Relapsed or Refractory Multiple Myeloma

BACKGROUND

Preclinical studies suggest that bb2121, a chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA), has potential for the treatment of multiple myeloma.

METHODS

In this phase 1 study involving patients with relapsed or refractory multiple myeloma, we administered bb2121 as a single infusion at doses of 50×10⁶, 150×10⁶, 450×10⁶, or 800×10⁶ CAR-positive (CAR+) T cells in the dose-escalation phase and 150×10⁶ to 450×10⁶ CAR+ T cells in the expansion phase. Patients had received at least three previous lines of therapy, including a proteasome inhibitor and an immunomodulatory agent, or were refractory to both drug classes. The primary end point was safety.

RESULTS

Results for the first 33 consecutive patients who received a bb2121 infusion are reported. The data-cutoff date was 6.2 months after the last infusion date. Hematologic toxic effects were the most common events of grade 3 or higher, including neutropenia (in 85% of the patients), leukopenia (in 58%), anemia (in 45%), and thrombocytopenia (in 45%). A total of 25 patients (76%) had cytokine release syndrome, which was of grade 1 or 2 in 23 patients (70%) and grade 3 in 2 patients (6%). Neurologic toxic effects occurred in 14 patients (42%) and were of grade 1 or 2 in 13 patients (39%). One patient (3%) had a reversible grade 4 neurologic toxic effect. The objective response rate was 85%, including 15 patients (45%) with complete responses. Six of the 15 patients who had a complete response have had a relapse. The median progression-free survival was 11.8 months (95% confidence interval, 6.2 to 17.8). All 16 patients who had a response (partial response or better) and who could be evaluated for minimal residual disease (MRD) had MRD-negative status (≤10^-4 nucleated cells). CAR T-cell expansion was associated with responses, and CAR T cells persisted up to 1 year after the infusion.

CONCLUSIONS

We report the initial toxicity profile of a BCMA-directed cellular immunotherapy for patients with relapsed or refractory multiple myeloma. Antitumor activity was documented. (Funded by Bluebird Bio and Celgene; CRB-401 ClinicalTrials.gov number, NCT02658929.).

A niche-dependent myeloid transcriptome signature defines dormant myeloma cells

The era of targeted therapies has seen significant improvements in depth of response, progression-free survival, and overall survival for patients with multiple myeloma. Despite these improvements in clinical outcome, patients inevitably relapse and require further treatment. Drug-resistant dormant myeloma cells that reside in specific niches within the skeleton are considered a basis of disease relapse but remain elusive and difficult to study. Here, we developed a method to sequence the transcriptome of individual dormant myeloma cells from the bones of tumor-bearing mice. Our analyses show that dormant myeloma cells express a distinct transcriptome signature enriched for immune genes and, unexpectedly, genes associated with myeloid cell differentiation. These genes were switched on by coculture with osteoblastic cells. Targeting AXL, a gene highly expressed by dormant cells, using small-molecule inhibitors released cells from dormancy and promoted their proliferation. Analysis of the expression of AXL and coregulated genes in human cohorts showed that healthy human controls and patients with monoclonal gammopathy of uncertain significance expressed higher levels of the dormancy signature genes than patients with multiple myeloma. Furthermore, in patients with multiple myeloma, the expression of this myeloid transcriptome signature translated into a twofold increase in overall survival, indicating that this dormancy signature may be a marker of disease progression. Thus, engagement of myeloma cells with the osteoblastic niche induces expression of a suite of myeloid genes that predicts disease progression and that comprises potential drug targets to eradicate dormant myeloma cells.

Loc108167440 suppressed myeloma cell growth by P53-mediated apoptosis

Multiple myeloma (MM) results from biased proliferation of cancerous plasma cells (PC). Therapeutic strategies that target MM PC will provide immense value to the treatment of MM. For this, it is necessary to identify novel molecules that differ between MM PC and healthy PC. RNA sequencing was used to determine differences in gene expression profiles between LPS-induced plasmablasts (PB)/PC and the PB-like myeloma SP 2/0 cell line. Compared to LPS-induced PB/PC, SP 2/0 cells expressed significantly lower levels of Loc108167440 mRNA. Loc108167440 overexpression reduced the number of SP 2/0 cells by stimulating apoptotic cell death. In addition, Loc108167440 overexpression suppressed tumor progression in the SP 2/0 xenograft mouse model. Finally, we demonstrated that Loc108167440 overexpression up-regulated expression of p53 in SP 2/0 cells. These results suggest that Loc108167440 overexpression suppressed SP 2/0 cell growth by inducing p53-mediated apoptosis. Thus, Loc108167440 overexpression may be a potential therapy for treating MM.

The future of myeloma precision medicine: integrating the compendium of known drug resistance mechanisms with emerging tumor profiling technologies

Multiple myeloma (MM) is a hematologic malignancy that is considered mostly incurable in large part due to the inability of standard of care therapies to overcome refractory disease and inevitable drug-resistant relapse. The post-genomic era has been a productive period of discovery where modern sequencing methods have been applied to large MM patient cohorts to modernize our current perception of myeloma pathobiology and establish an appreciation for the vast heterogeneity that exists between and within MM patients. Numerous pre-clinical studies conducted in the last two decades have unveiled a compendium of mechanisms by which malignant plasma cells can escape standard therapies, many of which have potentially quantifiable biomarkers. Exhaustive pre-clinical efforts have evaluated countless putative anti-MM therapeutic agents and many of these have begun to enter clinical trial evaluation. While the palette of available anti-MM therapies is continuing to expand it is also clear that malignant plasma cells still have mechanistic avenues by which they can evade even the most promising new therapies. It is therefore becoming increasingly clear that there is an outstanding need to develop and employ precision medicine strategies in MM management that harness emerging tumor profiling technologies to identify biomarkers that predict efficacy or resistance within an individual's sub-clonally heterogeneous tumor. In this review we present an updated overview of broad classes of therapeutic resistance mechanisms and describe selected examples of putative biomarkers. We also outline several emerging tumor profiling technologies that have the potential to accurately quantify biomarkers for therapeutic sensitivity and resistance at genomic, transcriptomic and proteomic levels. Finally, we comment on the future of implementation for precision medicine strategies in MM and the clear need for a paradigm shift in clinical trial design and disease management.

Tolerability and safety of real-world use of pomalidomide in patients with relapsed/refractory multiple myeloma

Pomalidomide (POM) is a second-generation immunomodulatory agent with proven efficacy in patients with relapsed/refractory multiple myeloma (RRMM) proven to be refractory to previous treatment with lenalidomide (LEN) and bortezomib. We herein conducted a retrospective analysis of 14 RRMM patients receiving POM to determine its tolerability and safety in the clinical setting. The median age of the patients was 72 years (range, 58-84 years), and 85.7% of the patients were aged >70 years. The most frequent treatment dose was 3 mg/day. POM dose reductions were required in 54.5% (6/11) of the patients. The patient data were compared among three age groups (<70, 70-75 and >75 years) and there was only significant difference in daily POM treatment dose. The tolerability of POM must be confirmed, particularly in elderly patients. Dose reduction from 4 to 3 mg occurred during the second cycle in 83.3% (5/6) of the patients. It is important to determine the tolerability of POM in the early phases of treatment. The most frequently reported grade 3/4 hematological adverse events were neutropenia (64.3%), anemia (64.3%) and thrombocytopenia (57.1%). Although the median number of treatment cycles was 4 (range, 1-13), 21.4% (3/14) of the patients with a performance status (PS) of 3 were administered only 1 treatment cycle. The tolerability of POM was low among patients with poor PS and an aggressive treatment introduction should be avoided. However, 21.4% (3/14) of the patients were able to continue treatment for >1 year and some patients received long-term therapy. POM does not require dose modification for renal function, and multiple capsule doses are available, which is an advantage of POM compared with LEN. POM may be administered to late-stage RRMM patients in a real-world clinical setting, but elderly patients or those with poor PS must be treated with caution. In this manner, the treatment options for RRMM patients may be expanded by assessing the tolerability and safety of POM.

LIGHT/TNFSF14 as a New Biomarker of Bone Disease in Multiple Myeloma Patients Experiencing Therapeutic Regimens

We have previously shown that through the production of high LIGHT levels, immune cells contribute to both osteoclastogenesis and bone destruction in Multiple Myeloma (MM)-related bone disease. With the aim of further exploring the mechanisms underlying the development of MM-related bone disease, here we focused on a possible role of LIGHT in MM patients with active bone disease despite the treatment received. We detected LIGHT over-expression by circulating CD14⁺ monocytes from MM patients still showing active bone disease, despite the treatment. In addition, we found over-expression of receptor activator of nuclear factor kappa-B ligand (RANKL), whose pro-osteoclastogenic role is well-known, in T-lymphocytes isolated from the same patients. Although the percentages of circulating osteoclast progenitors, CD14⁺CD16⁺ monocytes, were higher in all the MM patients than in the controls spontaneous osteoclastogenesis occurred only in the cultures derived from PBMCs of MM patients with unresponsive bone disease. Of note, in the same cultures osteoclastogenesis was partially or completely inhibited, in a dose-dependent manner, by the addition of RANK-Fc or anti-LIGHT neutralizing antibody, demonstrating the contribution of both LIGHT and RANKL to the enhanced osteoclast formation observed. In addition, high serum levels of TRAP5b and CTX, the two markers of osteoclast activity, were detected in MM patients with bone disease not responsive to treatment. In conclusion, our study indicates a prominent role of LIGHT in the crosstalk among osteoclasts and immune cells, co-involved together with RANKL in the pathophysiological mechanisms leading to MM-related bone disease. This TNF superfamily member may thus be a possible new therapeutic target in MM-related bone disease.

BC094916 suppressed SP 2/0 xenograft tumor by down-regulating Creb1 and Bcl2 transcription

Background

Both multiple myeloma (MM) and systemic lupus erythematosus (SLE) are associated with abnormal production of plasma cells, although their pathological mechanism of each disease is different. The main characteristic of both diseases is uncontrolled differentiation of B cells into plasmablast/plasma cells. Despite continuous research on prognostic factors and the introduction of new agents for MM and SLE, treatments still do not exist for controlling plasmablast/plasma cells. Thus, it is necessary to identify novel therapeutic targets of plasmablast/plasma cells. Because of its plasmablast-like characteristics, the mus musculus myeloma SP 2/0 cell line was used in this study to test the effect of a novel therapeutic agent (BC094916 overexpression) on plasmablast/plasma cells.

Methods

We first determined gene expression profiles of plasma cells using Affymetrix microarrays and RNA-sequencing. The effect of BC094916 on SP 2/0 cell proliferation, cell cycle, and apoptosis was determined by CCK8 and fluorescence-activated cell sorting. The SP 2/0 xenograft mouse model was used to assess the impact of BC094916 on tumor progression. The luciferase reporter system was used to evaluate the effect of BC094916 on Creb1 and Bcl2 transcription.

Results

We found that BC094916 mRNA was decreased in plasma cells. The mouse myeloma cell line SP 2/0 expressed low levels of BC094916 mRNA, whereas BC094916 overexpression suppressed SP 2/0 cell proliferation by inducing apoptosis. BC094916 overexpression suppressed tumor progression in the SP 2/0 xenograft mouse model. We also found that BC094916 mediate apoptosis by suppressing transcription of the Creb1 and Bcl2 genes, which promote the transcription of eukaryotic translation initiation and elongation factor genes.

Conclusions

BC094916 overexpression suppressed Creb1 and Bcl2 transcription to induce cell apoptosis, which suppressed SP 2/0 proliferation and xenograft tumor progression. Thus, BC094916 overexpression may be a potential therapeutic agent for treatment of MM and autoimmune diseases such as SLE.

Successful retreatment with lenalidomide for relapsed and refractory multiple myeloma previously treated with bortezomib, lenalidomide and pomalidomide

WHAT IS KNOWN AND OBJECTIVES

Optimal strategies for treating patients with very advanced relapsed and refractory multiple myeloma (RRMM) have not been clarified.

CASE SUMMARY

A 80-year-old patient with RRMM experienced extramedullary relapse following treatment with bortezomib, lenalidomide and pomalidomide. However, he achieved very good partial remission after retreatment with lenalidomide.

WHAT IS NEW AND CONCLUSION

This report illustrates that patients with very advanced RRMM can still respond to prior therapy even after being exposed and refractory to several agents. Considering the depth or duration of response to prior treatment, "retreatment" may improve the outcome of frail RRMM.

Inhibition of HIF1α-Dependent Upregulation of Phospho-l-Plastin Resensitizes Multiple Myeloma Cells to Frontline Therapy

The introduction of novel frontline agents in multiple myeloma (MM), like immunomodulatory drugs and proteasome inhibitors, has improved the overall survival of patients. Yet, MM is still not curable, and drug resistance (DR) remains the main challenge. To improve the understanding of DR in MM, we established a resistant cell line (MOLP8/R). The exploration of DR mechanisms yielded an overexpression of HIF1α, due to impaired proteasome activity of MOLP8/R. We show that MOLP8/R, like other tumor cells, overexpressing HIF1α, have an increased resistance to the immune system. By exploring the main target genes regulated by HIF1α, we could not show an overexpression of these targets in MOLP8/R. We, however, show that MOLP8/R cells display a very high overexpression of LCP1 gene (l-Plastin) controlled by HIF1α, and that this overexpression also exists in MM patient samples. The l-Plastin activity is controlled by its phosphorylation in Ser5. We further show that the inhibition of l-Plastin phosphorylation restores the sensitivity of MOLP8/R to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs). Our results reveal a new target gene of DR, controlled by HIF1α.