Elotuzumab plus lenalidomide/dexamethasone for relapsed or refractory multiple myeloma: ELOQUENT-2 follow-up and post-hoc analyses on progression-free survival and tumour growth

Current status of bispecific antibodies and CAR-T therapies in multiple myeloma

Multiple myeloma (MM), a malignancy of plasma cells, is an incurable disease that is characterized by the neoplastic proliferation of plasma cells leading to extensive skeletal destruction. This includes osteolytic lesions, osteopenia, and pathologic fractures. MM is clinically manifested through bone pain, renal insufficiency, hypercalcemia, anemia, and recurrent infections. Its prevalence and the need for effective treatment underscore the importance of this research. Recent advancements in MM therapy have been significant, particularly with the integration of daratumumab into first-line treatments. The use of daratumumab in regimens such as DRD (Daratumumab, Revlimid, Dexamethasone) and D-RVd (Daratumumab, Lenalidomide, Bortezomib, Dexamethasone) represents a paradigm shift in the treatment landscape. GRIFFIN and CASSIOPEIA trials have highlighted the efficacy of these regimens, particularly in prolonging progression-free survival and deepening patient responses. The shift from older regimens like MPV (Melphalan, Prednisone, Velcade) to more effective ones like DRD and RVD has been pivotal in treatment strategies. This review also focuses on the potential of Chimeric Antigen Receptor T-cell therapy and bispecific antibodies in MM. CAR-T therapy, which has shown success in other hematological malignancies, is being explored for its ability to specifically target MM cells. The latest clinical trials and research findings are analyzed to evaluate the efficacy and challenges of CAR-T therapy in MM. Additionally, the role of bispecific antibodies, which are designed to bind both cancer cells and T cells, is explored. These antibodies offer a unique mechanism that could complement the effects of CAR-T therapy.

Research progress of the chemokine/chemokine receptor axes in the oncobiology of multiple myeloma (MM)

BACKGROUND

The incidence of multiple myeloma (MM), a type of blood cancer affecting monoclonal plasma cells, is rising. Although new drugs and therapies have improved patient outcomes, MM remains incurable. Recent studies have highlighted the crucial role of the chemokine network in MM's pathological mechanism. Gaining a better understanding of this network and creating an overview of chemokines in MM could aid in identifying potential biomarkers and developing new therapeutic strategies and targets.

PURPOSE

To summarize the complicated role of chemokines in MM, discuss their potential as biomarkers, and introduce several treatments based on chemokines.

METHODS

Pubmed, Web of Science, ICTRP, and Clinical Trials were searched for articles and research related to chemokines. Publications published within the last 5 years are selected.

RESULTS

Malignant cells can utilize chemokines, including CCL2, CCL3, CCL5, CXCL7, CXCL8, CXCL12, and CXCL13 to evade apoptosis triggered by immune cells or medication, escape from bone marrow and escalate bone lesions. Other chemokines, including CXCL4, CCL19, and CXCL10, may aid in recruiting immune cells, increasing their cytotoxicity against cancer cells, and inducing apoptosis of malignant cells.

CONCLUSION

Utilizing anti-tumor chemokines or blocking pro-tumor chemokines may provide new therapeutic strategies for managing MM. Inspired by developed CXCR4 antagonists, including plerixafor, ulocuplumab, and motixafortide, more small molecular antagonists or antibodies for pro-tumor chemokine ligands and their receptors can be developed and used in clinical practice. Along with inhibiting pro-tumor chemokines, studies suggest combining chemokines with chimeric antigen receptor (CAR)-T therapy is promising and efficient.

Cardiovascular toxicity from therapies for light chain amyloidosis

Amyloid light-chain (AL) amyloidosis is a hematological disorder characterized by abnormal proliferation of a plasma cell clone producing monoclonal free light chains that misfold and aggregate into insoluble fibrils in various tissues. Cardiac involvement is a common feature leading to restrictive cardiomyopathy and poor prognosis. Current first-line treatments aim at achieving hematological response by targeting the plasma cell clones, and these have been adapted from multiple myeloma therapy. Patients with AL amyloidosis often exhibit multiorgan involvement, making them susceptible to cancer therapy-related cardiovascular toxicity. Managing AL amyloidosis is a complex issue that requires enhanced knowledge of the cardio-oncological implications of hematological treatments. Future research should focus on implementing and validating primary and secondary prevention strategies and understanding the biochemical basis of oncological therapy-related damage to mitigate cardiovascular toxicity.

[Multiple Myeloma Treatment Guidelines by the Portuguese Group of Multiple Myeloma]

The treatment of multiple myeloma has profoundly changed with the introduction of several innovative therapies. The optimization of therapeutic sequencing through the combined use of the various drugs developed in recent years and the attention given to the characteristics of patients have allowed the reduction of toxicities and increased survival and quality of life of patients with multiple myeloma. These treatment recommendations from the Portuguese Multiple Myeloma Group offer guidance for first-line treatment and progression/relapse situations. These recommendations are given highlighting the data that justify each choice and referring to the respective levels of evidence that support these options. Whenever possible, the respective national regulatory framework is presented. These recommendations constitute an advance towards the best treatment of multiple myeloma in Portugal.

Sequential CAR T cell and targeted alpha immunotherapy in disseminated multiple myeloma

Multiple myeloma (MM) is still an incurable disorder despite improved antibody and cellular therapies against different MM antigens. Single targeted antigens have so far been ineffective against MM with most patients relapsing after initial response. Hence, sequential immunotherapies directed at different targets are expected to perform better than monotherapy alone. Here, we optimized and established in preclinical studies the therapeutic rationale of using targeted alpha therapy (TAT) directed against CD38 antigen (²²⁵Ac-DOTA-daratumumab) with CAR T cell therapy directed at CS1 antigen in a systemic MM model. The sequential therapies compared CAR T therapy followed by TAT to TAT followed by CAR T therapy. CAR T cell monotherapy increased median survival from 49 days (d) in untreated controls to 71d with a modest improvement to 89d for 3.7 kBq of TAT given 14d later. When CAR T was followed by 7.4 kBq of TAT 29d later, sequential therapy increased median survival from 47d in untreated controls to 106d, compared to 68d for CAR T monotherapy. When CAR T therapy was followed by untargeted alpha immunotherapy using 7.4 kBq of ²²⁵Ac-DOTA-trastuzumab (anti-HER2) antibody 29d later, there was only a slight improvement in response over CAR T monotherapy demonstrating the role of tumor targeting. TAT (7.4 kBq) followed by CAR T therapy was also effective when CAR T therapy was delayed for 21d vs 14d or 28d post TAT, highlighting the importance of timing sequential therapies. Sequential targeted therapies using CS1 CAR T or ²²⁵Ac-DOTA-CD38 TAT in either order shows promise over monotherapies alone.

Cardiac toxicities in multiple myeloma: an updated and a deeper look into the effect of different medications and novel therapies

With the continuous improvement in survival of cancer patients, including those with multiple myeloma, related to the novel treatment agents and therapeutic approaches, the probability for patients to develop cardiovascular disease has significantly increased, especially in elderly patients and those with additional risk factors. Multiple myeloma is indeed a disease of the elderly population and so these patients are, solely by age, at an increased risk of cardiovascular disease. Risk factors for these events can be patient-, disease- and/or therapy-related, and they have been shown to adversely impact survival. Cardiovascular events affect around 7.5% of patients with multiple myeloma and the risk for different toxicities has considerably varied across trials depending on patients' characteristics and treatment utilized. High grade cardiac toxicity has been reported with immunomodulatory drugs (odds ratio [OR] around 2), proteasome inhibitors (OR 1.67-2.68 depending on the specific agent, and generally higher with carfilzomib), as well as other agents. Cardiac arrhythmias have also been reported with various therapies and drug interaction plays a significant role in that setting. Comprehensive cardiac evaluation before, during and after various anti-myeloma therapy is recommended and the incorporation of surveillance strategies allows early detection and management resulting in improved outcomes of these patients. Multidisciplinary interaction including hematologists and cardio-oncologists is critical for optimal patient care.

Past, Present, and a Glance into the Future of Multiple Myeloma Treatment

Multiple myeloma (MM) is a challenging hematological cancer which typically grows in bone marrow. MM accounts for 10% of hematological malignancies and 1.8% of cancers. The recent treatment strategies have significantly improved progression-free survival for MM patients in the last decade; however, a relapse for most MM patients is inevitable. In this review we discuss current treatment, important pathways for proliferation, survival, immune suppression, and resistance that could be targeted for future treatments.

Safety and efficacy of Elotuzumab combination therapy for patients with multiple myeloma: A systematic review and meta-analysis

OBJECTIVE

We evaluate the efficacy and safety of Elotuzumab, an immunostimulatory monoclonal antibody, in combination with concomitant treatment regimens for multiple myeloma (MM) patients.

RESEARCH DESIGN AND METHODS

PubMed, Scopus, Web of Science, and EMBASE databases were searched systematically up to 2 August 2022.

RESULTS

Five randomized control trials with a total of 1,763 participants were included. Elotuzumab combination therapy improved PFS and OS by 14% (hazard ratio [HR] 0.86) and 20% (HR 0.80), respectively, relative to the non-Elotuzumab regimen. Adding Elotuzumab to Lenalidomide plus Dexamethasone regimen (HR 0.82) or Pomalidomide plus Dexamethasone regimen (HR 0.54) were considered to improve the PFS. Meanwhile, the risk of disease progression was only reduced for patients with relapsed/refractory MM (HR 0.70) but not for newly diagnosed/untreated MM (HR 0.93). Finally, the risk of serious adverse events (RR 1.12) and the risk of infection (RR 1.09) and cardiac disorders (RR 1.32) were higher for the experimental group compared to the control group.

CONCLUSIONS

Our findings showed that Elotuzumab combination therapy prolonged OS and PFS compared to non-Elotuzumab treatments in patients with MM. However, further investigations are required to establish the most effective combination of the Elotuzumab regimen.

How to Manage Patients with Lenalidomide-Refractory Multiple Myeloma

Although lenalidomide-based combinations, such as lenalidomide plus a proteasome inhibitor or an anti-CD38 monoclonal antibody, improve the overall response rate, progression-free survival, and overall survival of patients with relapsed/refractory multiple myeloma (RRMM), there is a tendency to use these regimens as a frontline treatment. This strategy has led to the development of refractoriness early in the disease course, usually after the patient's first treatment. Since lenalidomide-free regimens have so far shown limited efficacy in lenalidomide-refractory patients, there is an unmet need for other treatment options. In this review, we discuss the therapeutic options available to treat the general population of lenalidomide-refractory patients (mono, double and triple refractory) and the subpopulation of patients with other high-risk features such as renal failure, extramedullary disease, and high-risk cytogenetics. Moreover, new promising individual therapies and the possible impact of immunotherapy in RRMM patients are debated.

Aiding early clinical drug development by elucidation of the relationship between tumor growth inhibition and survival in relapsed/refractory multiple myeloma patients

Early prognosis of clinical efficacy is an urgent need for oncology drug development. Herein, we systemically examined the quantitative approach of tumor growth inhibition (TGI) and survival modeling in the space of relapsed and refractory multiple myeloma (MM), aiming to provide insights into clinical drug development. Longitudinal serum M-protein and progression-free survival (PFS) data from three phase III studies (N = 1367) across six treatment regimens and different patient populations were leveraged. The TGI model successfully described the longitudinal M-protein data in patients with MM. The tumor inhibition and growth parameters were found to vary as per each study, likely due to the patient population and treatment regimen difference. Based on a parametric time-to-event model for PFS, M-protein reduction at week 4 was identified as a significant prognostic factor for PFS across the three studies. Other factors, including Eastern Cooperative Oncology Group performance status, prior anti-myeloma therapeutics, and baseline serum ß2-microglobulin level, were correlated with PFS as well. In conclusion, patient disease characteristics (i.e., baseline tumor burden and treatment lines) were important determinants of tumor inhibition and PFS in MM patients. M-protein change at week 4 was an early prognostic biomarker for PFS.

Harnessing the T Cell to Treat Multiple Myeloma: Dawn of a New Therapeutic Paradigm

Multiple myeloma is an incurable hematologic malignancy. The typical disease course for myeloma patients is characterized by initial response to treatment followed by eventual development of resistance. Subsequent cycles of remission and relapse proceed as long as patients have new lines of therapy available to them. This reality has prompted development of many novel immunotherapeutics. Many of these drugs exploit the cytotoxic capabilities of the patients' own T cells, effectively redirecting them to myeloma cells that are otherwise evading immune attack. Approaches including CAR T cell therapy and bispecific antibodies have displayed impressive efficacy in clinical trials for myeloma patients. This review examines the different approaches that utilize T cells in multiple myeloma therapy and investigates the benefits and risks of these exciting new strategies.

CS1 CAR-T targeting the distal domain of CS1 (SLAMF7) shows efficacy in high tumor burden myeloma model despite fratricide of CD8+CS1 expressing CAR-T cells

Despite improvement in treatment options for myeloma patients, including targeted immunotherapies, multiple myeloma remains a mostly incurable malignancy. High CS1 (SLAMF7) expression on myeloma cells and limited expression on normal cells makes it a promising target for CAR-T therapy. The CS1 protein has two extracellular domains - the distal Variable (V) domain and the proximal Constant 2 (C2) domain. We generated and tested CS1-CAR-T targeting the V domain of CS1 (Luc90-CS1-CAR-T) and demonstrated anti-myeloma killing in vitro and in vivo using two mouse models. Since fratricide of CD8 + cells occurred during production, we generated fratricide resistant CS1 deficient Luc90- CS1- CAR-T (ΔCS1-Luc90- CS1- CAR-T). This led to protection of CD8 + cells in the CAR-T cultures, but had no impact on efficacy. Our data demonstrate targeting the distal V domain of CS1 could be an effective CAR-T treatment for myeloma patients and deletion of CS1 in clinical production did not provide an added benefit using in vivo immunodeficient NSG preclinical models.

Elotuzumab plus Lenalidomide and Dexamethasone in Relapsed/Refractory Multiple Myeloma: Extended 3-year follow-up of a multicenter, retrospective clinical experience with 319 cases outside of controlled clinical trials

The combination of elotuzumab, lenalidomide, and dexamethasone (EloRd) enhanced the clinical benefit over Rd with a manageable toxicity profile in the ELOQUENT-2 trial, leading to its approval in relapsed/refractory multiple myeloma (RRMM). The present study is a 3-year follow-up update of a previously published Italian real-life RRMM cohort of patients treated with EloRd. This revised analysis entered 319 RRMM patients accrued in 41 Italian centers. After a median follow-up of 36 months (range 6-55), 236 patients experienced disease progression or died. Median progression-free survival (PFS) and overall survival (OS) were 18.4 and 34 months, respectively. The updated multivariate analyses showed a significant reduction of PFS and OS benefit magnitude only in cases with ISS stage III. Major adverse events included grade 3/4 neutropenia (18.5%), anemia (15.4%), lymphocytopenia (12.5%), and thrombocytopenia (10.7%), while infection rates and pneumonia were 33.9% and 18.9%, respectively. No new safety signals with longer follow-up have been observed. Of 319 patients, 245 (76.7%) reached at least a partial remission. A significantly lower response rate was found in patients previously exposed to lenalidomide. In conclusion, our study confirms that EloRd is a safe and effective regimen for RRMM patients, maintaining benefits across multiple unfavorable subgroups. This article is protected by copyright. All rights reserved.

Multiple myeloma: 2022 update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy-proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) attributable to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥ 100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging.

RISK STRATIFICATION

The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. The presence of any two high risk factors is considered double-hit myeloma, and three or more high risk factors is triple-hit myeloma.

RISK-ADAPTED INITIAL THERAPY

In patients who are candidates for autologous stem cell transplantation, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard-risk patients can collect stem cells, get additional cycles of induction therapy, and delay transplant until first relapse. Patients who are not candidates for transplant are treated with VRd for approximately 8-12 cycles followed by maintenance or alternatively with daratumumab, lenalidomide, dexamethasone (DRd) until progression.

MAINTENANCE THERAPY

Standard-risk patients need lenalidomide maintenance, while bortezomib plus lenalidomide maintenance is needed for high-risk myeloma.

MANAGEMENT OF RELAPSED DISEASE

A triplet regimen is usually needed at relapse, with the choice of regimen varying with each successive relapse.

Oral ixazomib-dexamethasone vs oral pomalidomide-dexamethasone for lenalidomide-refractory, proteasome inhibitor-exposed multiple myeloma: a randomized Phase 2 trial

Multiple myeloma (MM) patients typically receive several lines of combination therapy and first-line treatment commonly includes lenalidomide. As patients age, they become less tolerant to treatment, requiring convenient/tolerable/lenalidomide-free options. Carfilzomib and/or bortezomib-exposed/intolerant, lenalidomide-refractory MM patients with ≥2 prior lines of therapy were randomized 3:2 to ixazomib-dexamethasone (ixa-dex) (n = 73) or pomalidomide-dexamethasone (pom-dex) (n = 49) until progression/toxicity. Median progression-free survival (mPFS) was 7.1 vs 4.8 months with ixa-dex vs pom-dex (HR 0.847, 95% CI 0.535-1.341, P = 0.477; median follow-up: 15.3 vs 17.3 months); there was no statistically significant difference between arms. In patients with 2 and ≥3 prior lines of therapy, respectively, mPFS was 11.0 vs 5.7 months (HR 1.083, 95% CI 0.547-2.144) and 5.7 vs 3.7 months (HR 0.686, 95% CI 0.368-1.279). Among ixa-dex vs pom-dex patients, 69% vs 81% had Grade ≥3 treatment-emergent adverse events (TEAEs), 51% vs 53% had serious TEAEs, 39% vs 36% had TEAEs leading to drug discontinuation, 44% vs 32% had TEAEs leading to dose reduction, and 13% vs 13% died on study. Quality of life was similar between arms and maintained during treatment. Ixa-dex represents an important lenalidomide-free, oral option for this heavily pretreated, lenalidomide-refractory, proteasome inhibitor-exposed population.Trial registration: ClinicalTrials.gov number, NCT03170882.

How I Treat Relapsed Multiple Myeloma

Despite recent advances multiple myeloma remains an incurable disease for most of the patients and initial remission will be followed by relapses requiring therapy. For many, there will be several remissions and relapses until resistance develops to all available therapies. With the introduction of several new agents, myeloma treatment has changed drastically and there are new options for the management of relapsed or refractory disease, including new drug classes with distinct mechanisms of action and cellular therapies. However, resistance to major drug classes used in first line remain the most critical factor for the choice of treatment at relapse. Continuous lenalidomide-based therapy is used extensively at first line and resistance to lenalidomide has become the key factor for the choice of salvage therapy. Daratumumab is increasingly used in first line and soon patients that relapse while on daratumumab will become a common challenge. Three-drug regimens are standard approach to manage relapsed disease. Adding drugs with new mechanisms of activity can improves outcomes and overcomes class resistance but, until now, while the biology is important, can offer only limited guidance for the choice of therapy.

Optimising cardiovascular care of patients with multiple myeloma

Multiple myeloma (MM) is the third most common haematological malignancy, with increasing prevalence over recent years. Advances in therapy have improved survival, changing the clinical course of MM into a chronic condition and meaning that management of comorbidities is fundamental to improve clinical outcomes. Cardiovascular (CV) events affect up to 7.5% of individuals with MM, due to a combination of patient, disease and treatment-related factors and adversely impact survival. MM typically affects older people, many with pre-existing CV risk factors or established CV disease, and the disease itself can cause renal impairment, anaemia and hyperviscosity, which exacerabate these further. Up to 15% of patients with MM develop systemic amyloidosis, with prognosis determined by the extent of cardiac involvement. Management of MM generally involves administration of multiple treatment lines over several years as disease progresses, with many drug classes associated with adverse CV effects including high rates of venous and arterial thrombosis alongside heart failure. Recommendations for holistic management of patients with MM now include routine baseline risk stratification including ECG and echocardiography and administration of thromboprophylaxis drugs for patients treated with immunomodulatory drugs. Close surveillance of high-risk patients with collaboration between haematology and cardiology is required, with prompt investigation in the event of CV symptoms, in order to identify and treat complications early. Decisions regarding discontinuation of cardiotoxic therapies should be made in a multidisciplinary setting, taking into account the severity of the complication, prognosis, expected benefits and the availability of effective alternatives.

Rapid Progress in the Use of Immunomodulatory Drugs and Cereblon E3 Ligase Modulators in the Treatment of Multiple Myeloma

Over the past two decades, the improvement in our understanding of the biology of MM and the introduction of new drug classes, including immunomodulatory drugs (IMiDs), proteasome inhibitors (PI), and monoclonal antibodies (MoAb), have significantly improved outcomes. The first IMiD introduced to treat MM was thalidomide. The side effects observed during treatment with thalidomide initiated work on the synthesis of IMiD analogs. Subsequently, lenalidomide and pomalidomide were developed, both with different safety profiles, and they have better tolerability than thalidomide. In 2010, the cereblon (CRBN) protein was discovered as a direct target of IMiDs. By binding to CRBN, IMiDs change the substrate specificity of the CRBN E3 ubiquitin ligase complex, which results in the breakdown of internal Ikaros and Aiolos proteins. Most clinical trials conducted, both in newly diagnosed, post-transplant maintenance and relapsed/refractory MM, report a beneficial effect of IMiDs on the extension of progression-free survival and overall survival in patients with MM. Due to side effects, thalidomide is used less frequently. Currently, lenalidomide is used at every phase of MM treatment. Lenalidomide is used in conjunction with other agents such as PIs and MoAb as induction and relapsed therapy. Pomalidomide is currently used to treat relapsed/refractory MM, also with PIs and monoclonal antibodies. Current clinical trials are evaluating the efficacy of IMiD derivatives, the CRBN E3 ligase modulators (CELMoDs). This review focuses on the impact of IMiDs for the treatment of MM.

Immunotherapy of Multiple Myeloma: Promise and Challenges

Whereas the treatment of MM was dependent solely on alkylating agents and corticosteroids during the prior three decades, the landscape of therapeutic measures to treat the disease began to expand enormously early in the current century. The introduction of new classes of small-molecule drugs, such as proteasome blockers (bortezomib and carfilzomib), immunomodulators (lenalidomide and pomalidomide), nuclear export inhibitors (selinexor), and histone deacetylase blockers (panobinostat), as well as the application of autologous stem cell transplantation (ASCT), resulted in a seismic shift in how the disease is treated. The picture changed dramatically once again starting with the 2015 FDA approval of two monoclonal antibodies (mAbs) - the anti-CD38 daratumumab and the anti-SLAMF7 elotuzumab. Daratumumab, in particular, has had a great impact on MM therapy and today is often included in various regimens to treat the disease, both in newly diagnosed cases and in the relapse/refractory setting. Recently, other immunotherapies have been added to the arsenal of drugs available to fight this malignancy. These include isatuximab (also anti-CD38) and, in the past year, the antibody-drug conjugate (ADC) belantamab mafodotin and the chimeric antigen receptor (CAR) T-cell product idecabtagene vicleucel (ide-cel). While the accumulated benefits of these newer agents have resulted in a doubling of the disease's five-year survival rate to more than 5 years and improved quality of life, the disease remains incurable. Almost without exception patients experience relapse and/or become refractory to the drugs used, making the search for innovative therapies all the more essential. This review covers the current scope of anti-myeloma immunotherapeutic agents, both those in clinical use and on the horizon, including naked mAbs, ADCs, bi- and multi-targeted mAbs, and CAR T-cells. Emphasis is placed on the benefits of each along with the challenges that need to be overcome if MM is to be considered curable in the future.

The evolving status of immunotherapies in multiple myeloma: the future role of bispecific antibodies

Treatment outcomes in multiple myeloma (MM) have improved dramatically over the past 10 years. However, patients with high-risk disease such as those with Stage III disease by the Revised International Staging System, the presence of adverse cytogenetics, or who are refractory to proteosome inhibitors, immunomodulatory drugs and monoclonal antibodies may have dismal outcomes. These patients represent an urgent ongoing need in MM. One of the hallmarks of MM is immune dysfunction and a tumour-permissive immune microenvironment. Ameliorating the immune-paresis could lead to improved outcomes. The role of immunotherapies has been growing at an exponential pace with numerous agents under development in clinical trials. In the present review, we provide an overview of immunotherapies in MM, focussing on bispecific antibodies (BsAbs). We review efficacy outcomes from the published clinical trials and consider the important safety aspects of these therapies, in particular the risk of cytokine-release syndrome and immune effector cell-associated neurotoxicity syndrome, and how these compare with patients receiving chimeric antigen receptor T cells. We discuss the MM epitopes being targeted by BsAbs, either in clinical or preclinical stages, and we consider where these therapies might best fit within the future ever-changing paradigm of MM treatment.

Orthogonal targeting of osteoclasts and myeloma cells for radionuclide stimulated dynamic therapy induces multidimensional cell death pathways

Rationale: Multiple myeloma (MM) is a multifocal malignancy of bone marrow plasma cells, characterized by vicious cycles of remission and relapse that eventually culminate in death. The disease remains mostly incurable largely due to the complex interactions between the bone microenvironment (BME) and MM cells (MMC). In the “vicious cycle” of bone disease, abnormal activation of osteoclasts (OCs) by MMC causes severe osteolysis, promotes immune evasion, and stimulates the growth of MMC. Disrupting these cancer-stroma interactions would enhance treatment response.

Methods: To disrupt this cycle, we orthogonally targeted nanomicelles (NM) loaded with non-therapeutic doses of a photosensitizer, titanocene (TC), to VLA-4 (α4ß1, CD49d/CD29) expressing MMC (MM1.S) and αvß3 (CD51/CD61) expressing OC. Concurrently, a non-lethal dose of a radiopharmaceutical, ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) administered systemically interacted with TC (radionuclide stimulated therapy, RaST) to generate cytotoxic reactive oxygen species (ROS). The in vitro and in vivo effects of RaST were characterized in MM1.S cell line, as well as in xenograft and isograft MM animal models.

Results: Our data revealed that RaST induced non-enzymatic hydroperoxidation of cellular lipids culminating in mitochondrial dysfunction, DNA fragmentation, and caspase-dependent apoptosis of MMC using VLA-4 avid TC-NMs. RaST upregulated the expression of BAX, Bcl-2, and p53, highlighting the induction of apoptosis via the BAK-independent pathway. The enhancement of multicopper oxidase enzyme F5 expression, which inhibits lipid hydroperoxidation and Fenton reaction, was not sufficient to overcome RaST-induced increase in the accumulation of irreversible function-perturbing α,ß-aldehydes that exerted significant and long-lasting damage to both DNA and proteins. In vivo, either VLA-4-TC-NM or αvß3-TC-NMs RaST induced a significant therapeutic effect on immunocompromised but not immunocompetent MM-bearing mouse models. Combined treatment with both VLA-4-TC-NM and αvß3-TC-NMs synergistically inhibited osteolysis, reduced tumor burden, and prevented rapid relapse in both in vivo models of MM.

Conclusions: By targeting MM and bone cells simultaneously, combination RaST suppressed MM disease progression through a multi-prong action on the vicious cycle of bone cancer. Instead of using the standard multidrug approach, our work reveals a unique photophysical treatment paradigm that uses nontoxic doses of a single light-sensitive drug directed orthogonally to cancer and bone cells, followed by radionuclide-stimulated generation of ROS to inhibit tumor progression and minimize osteolysis in both immunocompetent murine and immunocompromised human MM models.

Retrospective study of treatment patterns and outcomes post-lenalidomide for multiple myeloma in Canada

Lenalidomide is an important component of initial therapy in newly diagnosed multiple myeloma, either as maintenance therapy post-autologous stem cell transplantation (ASCT) or as first-line therapy with dexamethasone for patients' ineligible for ASCT (non-ASCT). This retrospective study investigated treatment patterns and outcomes for ASCT-eligible and -ineligible patients who relapsed after lenalidomide as part of first-line therapy, based on data from the Canadian Myeloma Research Group Database for patients treated between January 2007 and April 2019. Among 256 patients who progressed on lenalidomide maintenance therapy, 28.5% received further immunomodulatory derivative-based (IMiD-based) therapy (lenalidomide/pomalidomide) without a proteasome inhibitor (PI) (bortezomib/carfilzomib/ixazomib), 26.2% received PI-based therapy without an IMiD, 19.5% received both an IMiD plus PI, 13.5% received daratumumab-based regimens, and 12.1% underwent salvage ASCT. Median progression-free survival (PFS) was longest for daratumumab-based therapy (22.7 months) and salvage ASCT (23.4 months) and ranged from 6.6 to 7.3 months for the other treatments (P < .0001). Median overall survival (OS) was also longest for daratumumab and salvage ASCT. A total of 87 non-ASCT patients received subsequent therapy, with 66.7% receiving bortezomib-based therapy and 13.8% receiving other PI-based therapy. Median PFS was 15.4 and 24.8 months for bortezomib-based and other PI-based therapy, respectively (P = .404). During most of the study period, daratumumab was not funded; in this setting, switching to a different therapeutic class following relapse on lenalidomide produced the longest remissions for non-ASCT patients. Further prospective studies are warranted to determine optimum treatment following relapse on lenalidomide, especially in the light of increased access to daratumumab.

When and How to Treat Relapsed Multiple Myeloma

The treatment landscape for relapsed multiple myeloma has expanded considerably in recent years, as numerous agents with new mechanisms of action have been introduced, increasing responses even in advanced disease and prolonging survival. The wealth of novel regimens comes with the challenges of balancing toxicities and aligning a regimen with the biology of the myeloma and the nature of the relapse in conjunction with patient treatment history and personal preference. Herein, we provide an overview of treatment options for both early and late relapsing disease as well as a discussion of the role of emerging immune-based therapies.

Pegfilgrastim for primary prophylaxis of febrile neutropenia in multiple myeloma

Multiple myeloma (MM) survival rates have been substantially increased thanks to novel agents that have improved survival outcomes and shown better tolerability than treatments of earlier years. These new agents include immunomodulating imide drugs (IMiD) thalidomide and lenalidomide, the proteasome inhibitor bortezomib (PI), recently followed by new generation IMID pomalidomide, monoclonal antibodies daratumumab and elotuzumab, and next generation PI carfilzomib and ixazomib. However, even in this more promising scenario, febrile neutropenia remains a severe side effect of antineoplastic therapies and can lead to a delay and/or dose reduction in subsequent cycles. Supportive care has thus become key in helping patients to obtain the maximum benefit from novel agents. Filgrastim is a human recombinant subcutaneous preparation of G-CSF, largely adopted in hematological supportive care as "on demand" (or secondary) prophylaxis to recovery from neutropenia and its infectious consequences during anti-myeloma treatment. On the contrary, pegfilgrastim is a pegylated long-acting recombinant form of granulocyte colony-stimulating factor (G-CSF) that, given its extended half-life, can be particularly useful when adopted as "primary prophylaxis," therefore before the onset of neutropenia, along chemotherapy treatment in multiple myeloma patients. There is no direct comparison between the two G-CSF delivery modalities. In this review, we compare data on the two administrations' modality, highlighting the efficacy of the secondary prophylaxis over multiple myeloma treatment. Advantage of pegfilgrastim could be as follows: the fixed administration rather than multiple injections, reduction in neutropenia and febrile neutropenia rates, and, finally, a cost-effectiveness advantage.

Etiology and management of hypertension in patients with cancer

The pathophysiology of hypertension and cancer are intertwined. Hypertension has been associated with an increased likelihood of developing certain cancers and with higher cancer-related mortality. Moreover, various anticancer therapies have been reported to cause new elevated blood pressure or worsening of previously well-controlled hypertension. Hypertension is a well-established risk factor for the development of cardiovascular disease, which is rapidly emerging as one of the leading causes of death and disability in patients with cancer. In this review, we discuss the relationship between hypertension and cancer and the role that hypertension plays in exacerbating the risk for anthracycline- and trastuzumab-induced cardiomyopathy. We then review the common cancer therapies that have been associated with the development of hypertension, including VEGF inhibitors, small molecule tyrosine kinase inhibitors, proteasome inhibitors, alkylating agents, glucocorticoids, and immunosuppressive agents. When available, we present strategies for blood pressure management for each drug class. Finally, we discuss blood pressure goals for patients with cancer and strategies for assessment and management. It is of utmost importance to maintain optimal blood pressure control in the oncologic patient to reduce the risk of chemotherapy-induced cardiotoxicity and to decrease the risk of long-term cardiovascular disease.

Extramedullary relapse of multiple myeloma presenting as a breast lump

Multiple myeloma (MM) involving the breast tissue is rare. We report the case of a 70-year-old woman with a background of previously treated MM in remission presenting with a breast lump. Histology showed a plasma cell neoplasm and subsequent staging investigations showed widespread extramedullary relapse of MM. Despite its rarity, this diagnosis should be considered within the differential diagnosis of breast masses as it can arise de novo or may be the first presenting feature of myeloma. The importance of the multidisciplinary team approach with triple assessment of the breast, as well as recent advances in knowledge regarding extramedullary disease in myeloma and novel treatment approaches in MM are discussed.

Immunotherapy with Antibodies in Multiple Myeloma: Monoclonals, Bispecifics, and Immunoconjugates

In the 2010s, immunotherapy revolutionized the treatment landscape of multiple myeloma. CD38-targeting antibodies were initially applied as monotherapy in end-stage patients, but are now also approved by EMA/FDA in combination with standards-of-care in newly diagnosed disease or in patients with early relapse. The approved SLAMF7-targeting antibody can also be successfully combined with lenalidomide or pomalidomide in relapsed/refractory myeloma. Although this has resulted in improved clinical outcomes, there remains a high unmet need in patients who become refractory to immunomodulatory drugs, proteasome inhibitors and CD38-targeting antibodies. Several new antibody formats, such as antibody–drug conjugates (e.g., belantamab mafodotin, which was approved in 2020 and targets BCMA) and T cell redirecting bispecific antibodies (e.g., teclistamab, talquetamab, cevostamab, AMG-420, and CC-93269) are active in these triple-class refractory patients. Based on their promising efficacy, it is expected that these new antibody formats will also be combined with other agents in earlier disease settings.

Approaches and Challenges in the Management of Multiple Myeloma in the Very Old: Future Treatment Prospects

The increasing incidence of geriatric patients with multiple myeloma has elevated concerns in clinical practice. While the introduction of novel therapeutic agents has substantially improved outcomes in younger patients with myeloma, poorer outcomes remain in older patients. Managing older patients requires a multidisciplinary team approach to consider factors that may influence both treatment selection and outcomes. Aging is associated with remodeling of vital organs, physiological downregulations of basal metabolism, susceptibility to multiple comorbidities with ultimate frailty, thereby contributing to the underrepresentation and exclusion of very old patients from clinical trials. Therefore, timely confirmation of a precise diagnosis is crucial for prompt initiation of treatment if the desired outcome is to be achieved. Adequate and judicious assessment using comprehensive geriatric assessment tools minimizes toxicities and treatment discontinuation. Initiating treatment with combinational therapy requires knowledge of indications and anticipated outcomes, as well as individualized therapy with appropriate dose-adjustment. Individualized therapy based on good clinical acumen and best practices obverts unwanted polypharmacy, preventing iatrogenic harm. This review will therefore address the approaches and challenges faced in managing myeloma in geriatric patients aged 80 years and older, highlighting recommended therapeutic strategies and future prospective regimens.

Elotuzumab in the treatment of relapsed and refractory multiple myeloma

Multiple myeloma (MM) is still considered an incurable disease. However, drugs with different mechanisms of action that can improve the efficiency of treatment offer hope. Still, there are concerns about an unacceptable increase in toxicity with such regimens. The results of recently published clinical studies of elotuzumab in combination with lenalidomide/dexamethasone or pomalidomide/dexamethasone confirm previous hopes to improve the effect of that treatment. Humanized monoclonal antibodies aimed at SLAMF7 stimulate natural killer cells to fight against MM cells. Elotuzumab used in combination with lenalidomide/dexamethasone or with pomalidomide/dexamethasone is approved by the US FDA to treat patients with relapsed and/or refractory MM. The article is a summary of the recent knowledge about the possibility of using elotuzumab in the treatment of relapsed and/or refractory MM and shows its potential uses in the future.

Immune Functions of Signaling Lymphocytic Activation Molecule Family Molecules in Multiple Myeloma

Simple Summary

Multiple myeloma (MM) is an incurable hematological malignancy characterized by an increase in abnormal plasma cells. Disease progression, drug resistance, and immunosuppression in MM are associated with immune-related molecules, such as immune checkpoint and co-stimulatory molecules, present in the tumor microenvironment. Novel agents targeting these cell-surface molecules are currently under development, including monoclonal antibodies, bispecific monoclonal antibodies, and chimera antigen receptor T-cell therapies. In this review, we focus on the signaling lymphocytic activation molecule family receptors and provide an overview of their biological functions and novel therapies in MM.

Abstract

The signaling lymphocytic activation molecule (SLAM) family receptors are expressed on various immune cells and malignant plasma cells in multiple myeloma (MM) patients. In immune cells, most SLAM family molecules bind to themselves to transmit co-stimulatory signals through the recruiting adaptor proteins SLAM-associated protein (SAP) or Ewing’s sarcoma-associated transcript 2 (EAT-2), which target immunoreceptor tyrosine-based switch motifs in the cytoplasmic regions of the receptors. Notably, SLAMF2, SLAMF3, SLAMF6, and SLAMF7 are strongly and constitutively expressed on MM cells that do not express the adaptor proteins SAP and EAT-2. This review summarizes recent studies on the expression and biological functions of SLAM family receptors during the malignant progression of MM and the resulting preclinical and clinical research involving four SLAM family receptors. A better understanding of the relationship between SLAM family receptors and MM disease progression may lead to the development of novel immunotherapies for relapse prevention.

Drug Conjugated and Bispecific Antibodies for Multiple Myeloma: Improving Immunotherapies off the Shelf

The impressive improvement of overall survival in multiple myeloma (MM) patients in the last years has been mostly related to the availability of new classes of drugs with different mechanisms of action, including proteasome inhibitors (PI), immunomodulating agents (IMiDs), and monoclonal antibodies. However, even with this increased potence of fire, MM still remains an incurable condition, due to clonal selection and evolution of neoplastic clone. This concept underlines the importance of immunotherapy as one of the most relevant tools to try to eradicate the disease. In line with this concept, active and passive immunotherapies represent the most attractive approach to this aim. Antibody-drug conjugate(s) (ADCs) and bispecific antibodies (BsAbs) include two innovative tools in order to limit neoplastic plasma cell growth or even, if used at the time of the best response, to potentially eradicate the tumoral clone. Following their promising results as single agent for advanced disease, at the recent 62nd ASH meeting, encouraging data of several combinations, particularly of ADC(s) with PI or IMiDs, have been reported, suggesting even better results for patients treated earlier. In this paper, we reviewed the characteristics, mechanism of action, and clinical data available for most relevant ADC(s) and BsAbs.

Selective elimination of immunosuppressive T cells in patients with multiple myeloma

Elimination of suppressive T cells may enable and enhance cancer immunotherapy. Here, we demonstrate that the cell membrane protein SLAMF7 was highly expressed on immunosuppressive CD8⁺CD28^-CD57⁺ Tregs in multiple myeloma (MM). SLAMF7 expression associated with T cell exhaustion surface markers and exhaustion-related transcription factor signatures. T cells from patients with a high frequency of SLAMF7⁺CD8⁺ T cells exhibited decreased immunoreactivity towards the MART-1_aa26-35*A27L antigen. A monoclonal anti-SLAMF7 antibody (elotuzumab) specifically depleted SLAMF7⁺CD8⁺ T cells in vitro and in vivo via macrophage-mediated antibody-dependent cellular phagocytosis (ADCP). Anti-SLAMF7 treatment of MM patients depleted suppressive T cells in peripheral blood. These data highlight SLAMF7 as a marker for suppressive CD8⁺ Treg and suggest that anti-SLAMF7 antibodies can be used to boost anti-tumoral immune responses in cancer patients.

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.

Why Immunotherapy Fails in Multiple Myeloma

Multiple myeloma remains an incurable disease despite great advances in its therapeutic landscape. Increasing evidence supports the belief that immune dysfunction plays an important role in the disease pathogenesis, progression, and drug resistance. Recent efforts have focused on harnessing the immune system to exert anti-myeloma effects with encouraging outcomes. First-in-class anti-CD38 monoclonal antibody, daratumumab, now forms part of standard treatment regimens in relapsed and refractory settings and is shifting to front-line treatments. However, a non-negligible number of patients will progress and be triple refractory from the first line of treatment. Antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptors (CAR) are being developed in a heavily pretreated setting with outstanding results. Belantamab mafodotin-blmf has already received approval and other anti-B-cell maturation antigen (BCMA) therapies (CARs and bispecific antibodies are expected to be integrated in therapeutic options against myeloma soon. Nonetheless, immunotherapy faces different challenges in terms of efficacy and safety, and manufacturing and economic drawbacks associated with such a line of therapy pose additional obstacles to broadening its use. In this review, we described the most important clinical data on immunotherapeutic agents, delineated the limitations that lie in immunotherapy, and provided potential insights to overcome such issues.

Lenalidomide with dexamethasone to multiple myeloma patients relapsing from bortezomib-based induction therapies: A prospective, observational study

Lenalidomide with dexamethasone (Len/Dex) is considered to be an effective and well-tolerated regimen to treat multiple myeloma (MM) patients relapsing after bortezomib induction therapy. With the increase in novel agents targeting refractory and relapsed MM, the identification of clinical or laboratory variables that can predict the appropriate candidates of Len/Dex is essential. To address this question, we prospectively assessed 38 adult MM patients who received bortezomib-based induction therapy and were administered Len/Dex for their first relapse. These 38 patients were stratified into the symptomatic relapse group (n = 10) and biological relapse group (n = 28) according to the disease status when Len/Dex was initiated. The overall response rate in the symptomatic group and biological relapse group was 70.0% (7/10) and 60.7% (17/28), respectively (P = 0.964). These two groups harbored a comparable median Len/Dex treatment duration (139 vs. 225 days; P = 0.876) and progression-free survival 2 (PFS2) (501 vs. 1289 days; P = 0.410). Multivariate analyses failed to show that treating biological relapse (hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 0.43-3.88; P = 0.648), PFS with bortezomib-based induction therapies ≥18 months (HR: 1.79; 95% CI: 0.64-5.01; P = 0.266), autologous hematopoietic stem cell transplantation (HR: 2.18; 95% CI: 0.56-8.55; P = 0.262), and high-risk cytogenetics (HR: 0.85; 95% CI: 0.18-3.93; P = 0.835) were attributed to depth of Len/Dex treatment. In conclusion, whether MM patients treated by Len/Dex for biological relapse would have a better outcome than those prescribed for symptomatic relapse remains inconclusive. Treating significant biological relapse and symptomatic relapse remains the current consensus.

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.

CAR T-Cells in Multiple Myeloma Are Ready for Prime Time

The survival of patients with multiple myeloma (MM) has been dramatically improved in the last decade thanks to the incorporation of second-generation proteasome inhibitors (PI), immunomodulatory drugs (IMID), and, more recently, anti-CD38 monoclonal antibodies (MoAb). Nevertheless, still, a major proportion of MM patients will relapse, underscoring the need for new therapies in this disease. Moreover, survival in patients failing the current standard of care regimens (including PI, IMIDs, and anti-CD38 MoAb), which is now defined as triple-class refractory, remains dismal, and new drugs with different mechanism of action are needed. B-cell maturation antigen (BCMA)-targeted therapies and in particular chimeric antigen receptor T cell (CAR T-cell) treatment have emerged as promising platforms to overcome refractoriness to conventional drugs. In this manuscript, we review the current available data regarding CAR T-cell therapy for MM, with a special focus on target selection, clinical results, limitations, and future strategies.

Current developments in the combination therapy of relapsed/refractory multiple myeloma

INTRODUCTION

Therapy for patients with multiple myeloma has improved dramatically over the past decade following the introduction of novel agents and combinations across the disease spectrum. When relapse or refractory disease develops, non-cross-resistant drugs, most often used in multidrug regimens, have provided significant improvements in patient outcomes. Despite these advances, myeloma remains incurable and additional therapeutic approaches, based on emerging molecular and cellular biology, are moving rapidly through development phases. Approaches new to myeloma, including antibody-drug conjugates, T-cell-directed therapies, and novel small molecules, are poised to bring in the next wave of treatment.

AREAS COVERED

This review addresses recent data for the management of relapsed/refractory disease, rationale for agent and regimen selection and combinations, and options showing early promise in trials. Literature and abstracts pertaining to trial data published or presented up to 2019 are included.

EXPERT OPINION

Therapeutic strategies continue to evolve in myeloma, with the application of existing platforms (e.g., antibody-drug conjugates) to target relevant biology (e.g., B cell maturation antigen). Within the next year, there will be additional agents approved for those with advanced disease, and combinations as well as placement in sequencing will deepen responses and improve outcomes for patients.

Multiple myeloma current treatment algorithms

The treatment of multiple myeloma (MM) continues to evolve rapidly with arrival of multiple new drugs, and emerging data from randomized trials to guide therapy. Along the disease course, the choice of specific therapy is affected by many variables including age, performance status, comorbidities, and eligibility for stem cell transplantation. In addition, another key variable that affects treatment strategy is risk stratification of patients into standard and high-risk MM. High-risk MM is defined by the presence of t(4;14), t(14;16), t(14;20), gain 1q, del(17p), or p53 mutation. In this paper, we provide algorithms for the treatment of newly diagnosed and relapsed MM based on the best available evidence. We have relied on data from randomized controlled trials whenever possible, and when appropriate trials to guide therapy are not available, our recommendations reflect best practices based on non-randomized data, and expert opinion. Each algorithm has been designed to facilitate easy decision-making for practicing clinicians. In all patients, clinical trials should be considered first, prior to resorting to the standard of care algorithms we outline.

Old and new generation immunomodulatory drugs in multiple myeloma

INTRODUCTION

Over the last two decades, the outcomes of patients with multiple myeloma (MM), a malignant plasma cells dyscrasia, have dramatically improved. The development and the introduction of the immunomodulatory drugs (IMiDs) which include thalidomide, lenalidomide, and pomalidomide, have contributed significantly to these improvements.

EVIDENCE ACQUISITION

The IMiDs have been shown a multitude of mechanisms of action, including antiangiogenic, cytotoxic and immunomodulatory. The more recent discoveries that the IMiDs bind to cereblon and thus regulate the ubiquitination of key transcription factors including IKZF1 and IKZF3, have provided new insight about their activities.

EVIDENCE SYNTHESIS

The IMIDs are widely used in the treatment of the different setting of MM patients and particularly lenalidomide represents the backbone in the therapy of newly diagnosed transplant eligible and transplant ineligible patients, in the maintenance setting post-transplant and in the relapsed/refractory setting, while pomalidomide is currently utilized in the relapsed/refractory setting.

CONCLUSIONS

Here the mechanisms of action, the clinical efficacy and the management of side effects are reviewed as well as the new classes of cereblon E3 ligase modulator (CELMoD) and their promising clinical data are described.

Emerging immunotherapies in multiple myeloma

Despite considerable advances in treatment approaches in the past two decades, multiple myeloma remains an incurable disease. Treatments for myeloma continue to evolve with many emerging immunotherapies. The first immunotherapy used to treat hematologic cancers, including multiple myeloma, was an allogeneic stem cell transplant. In the mid-2000s, immunomodulatory drugs thalidomide, lenalidomide, and subsequently pomalidomide were proven to be effective in multiple myeloma and substantially improved survival. The next wave of immunotherapies for multiple myeloma included the monoclonal antibodies daratumumab and elotuzumab, which were approved by the Food and Drug Administration in 2015. Subsequently, a variety of immunotherapies have been developed for multiple myeloma, including chimeric antigen receptor T cells, bispecific antibodies, antibody drug conjugates, and checkpoint inhibitors. Many of these emerging treatments target the B cell maturation antigen, which is expressed on plasma cells, although several other novel receptors are also being studied. This review summarizes the evidence of these various immunotherapies, their mechanism of action, and data from clinical trials regarding the treatments' safety and efficacy.

Elotuzumab, lenalidomide, and dexamethasone in RRMM: final overall survival results from the phase 3 randomized ELOQUENT-2 study

Prolonging overall survival (OS) remains an unmet need in relapsed or refractory multiple myeloma (RRMM). In ELOQUENT-2 (NCT01239797), elotuzumab plus lenalidomide/dexamethasone (ERd) significantly improved progression-free survival (PFS) versus lenalidomide/dexamethasone (Rd) in patients with RRMM and 1–3 prior lines of therapy (LoTs). We report results from the pre-planned final OS analysis after a minimum follow-up of 70.6 months, the longest reported for an antibody-based triplet in RRMM. Overall, 646 patients with RRMM and 1–3 prior LoTs were randomized 1:1 to ERd or Rd. PFS and overall response rate were co-primary endpoints. OS was a key secondary endpoint, with the final analysis planned after 427 deaths. ERd demonstrated a statistically significant 8.7-month improvement in OS versus Rd (median, 48.3 vs 39.6 months; hazard ratio, 0.82 [95.4% Cl, 0.68–1.00]; P = 0.0408 [less than allotted α of 0.046]), which was consistently observed across key predefined subgroups. No additional safety signals with ERd at extended follow-up were reported. ERd is the first antibody-based triplet regimen shown to significantly prolong OS in patients with RRMM and 1–3 prior LoTs. The magnitude of OS benefit was greatest among patients with adverse prognostic factors, including older age, ISS stage III, IMWG high-risk disease, and 2–3 prior LoTs.

Elotuzumab-based maintenance therapy following autologous stem cell transplant in multiple myeloma deepens post-transplant responses

BACKGROUND

Post-transplant maintenance provides progression-free survival benefit in multiple myeloma (MM). Here we report our institution's experience with elotuzumab-based maintenance following autologous stem cell transplant.

METHODS

We retrospectively evaluated the outcomes of MM patients who were started on elotuzumab-based maintenance (elotuzumab/lenalidomide/dexamethasone, elotuzumab/bortezomib/dexamethasone, or elotuzumab/bortezomib/methylprednisolone) following transplant (N = 7). Baseline characteristics, treatment response, survival, and adverse events were reviewed.

RESULTS

Median age was 68 (56-81) years at the time of transplant, and median lines of induction therapy was 2 (1-6). Three patients (42.9%) had high-risk cytogenetics and five (71.4%) had stage II or greater disease at diagnosis. At a median follow-up of 24 months (12-50), five patients (71.4%) had improvement of quality of response, with a combined CR or VGPR rate increasing from 57.1% to 100% (CR = 3, VGPR = 4). All patients were alive without relapse or progression at the time of this analysis. Grade 3-4 adverse events were observed in three (42.9%) patients. None of the patients discontinued the treatment due to intolerance.

CONCLUSIONS

Our study demonstrates that elotuzumab-based maintenance may deepen response post-transplant in MM and can be safely administered even in older patients. Given its unique action and rare side effects, further studies of elotuzumab in the post-transplant setting are warranted.

Tumor Growth Dynamic Modeling in Oncology Drug Development and Regulatory Approval: Past, Present, and Future Opportunities

Model‐informed drug development (MIDD) approaches have rapidly advanced in drug development in recent years. Additionally, the Prescription Drug User Fee Act (PDUFA) VI has specific commitments to further enhance MIDD. Tumor growth dynamic (TGD) modeling, as one of the commonly utilized MIDD approaches in oncology, fulfills the purposes to accelerate the drug development, to support new drug and biologics license applications, and to guide the market access. Increasing knowledge of TGD modeling methodologies, encouraging applications in clinical setting for patients’ survival, and complementing assessment of regulatory review for submissions, together fueled promising potentials for imminent enhancement of TGD in oncology. This review is to comprehensively summarize the history of TGD, and present case examples of the recent advance of TGD modeling (mixture model and joint model), as well as the TGD impact on regulatory decisions, thus illustrating challenges and opportunities. Additionally, this review presents the future perspectives for TGD approach.

Preclinical Characterization of an Antibody-Drug Conjugate Targeting CS-1 and the Identification of Uncharacterized Populations of CS-1-Positive Cells

Multiple myeloma is a hematologic cancer that disrupts normal bone marrow function and has multiple lines of therapeutic options, but is incurable as patients ultimately relapse. We developed a novel antibody-drug conjugate (ADC) targeting CS-1, a protein that is highly expressed on multiple myeloma tumor cells. The anti-CS-1 mAb specifically bound to cells expressing CS-1 and, when conjugated to a cytotoxic pyrrolobenzodiazepine payload, reduced the viability of multiple myeloma cell lines in vitro In mouse models of multiple myeloma, a single administration of the CS-1 ADC caused durable regressions in disseminated models and complete regression in a subcutaneous model. In an exploratory study in cynomolgus monkeys, the CS-1 ADC demonstrated a half-life of 3 to 6 days; however, no highest nonseverely toxic dose was achieved, as bone marrow toxicity was dose limiting. Bone marrow from dosed monkeys showed reductions in progenitor cells as compared with normal marrow. In vitro cell killing assays demonstrated that the CS-1 ADC substantially reduced the number of progenitor cells in healthy bone marrow, leading us to identify previously unreported CS-1 expression on a small population of progenitor cells in the myeloid-erythroid lineage. This finding suggests that bone marrow toxicity is the result of both on-target and off-target killing by the ADC.

The Targeted Therapies Era Beyond the Surgical Point of View: What Spine Surgeons Should Know Before Approaching Spinal Metastases

In the last few years, the treatment of spinal metastases has significantly changed. This is due to the advancements in surgical technique, radiotherapy, and chemotherapy which have enriched the multidisciplinary management. Above all, the field of molecular biology of tumors is in continuous and prosperous evolution. In this review, the molecular markers and new approaches that have radically modified the chemotherapeutic strategy of the most common metastatic neoplasms will be examined together with clinical and surgical implications. The experience and skills of several different medical professionals are mandatory: an interdisciplinary oncology team represents the winning strategy in the treatment of patients with spinal metastases