SAR650984 directly induces multiple myeloma cell death via lysosomal-associated and apoptotic pathways, which is further enhanced by pomalidomide

Radiolabeling and cytotoxicity of monoclonal antibody Isatuximab functionalized silver nanoparticles on the growth of multiple myeloma

The goal of this article was to develop a new therapeutic strategy based on nanotechnology for multiple myeloma (MM) treatment which shows a synergism of different mechanisms. In this concern, 12.9 nm-sized silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). Furthermore, the synthesized nanocomposite was radiolabelled with iodine-131 radionuclide and yielded 95.5 ± 1.5%. Then, the synergistic MM-proliferation inhibition efficacy of the radionanocomposite (¹³¹I-Isatuximab/AgNPs) was explored in-vitro in comparison to each single agent. The MTT investigation showed that the antiproliferation effect of ¹³¹I-Isatuximab/AgNPs increased by more than 1.5 fold if compared with Isatuximab, AgNPs, Isatuximab/AgNPs or ¹³¹I-Isatuximab. Additionally, ¹³¹I-Isatuximab/AgNPs exhibited an apoptotic effect on MM cells which was more than that of Isatuximab, AgNPs, Isatuximab/AgNPs or ¹³¹I-Isatuximab by 2, 1.8, 1.7 and 1.5 folds, respectively. In conclusion, the results expressed ¹³¹I-Isatuximab/AgNPs as a potential new anti-MM agent.

Treatment Options for Patients With Heavily Pretreated Relapsed and Refractory Multiple Myeloma

Despite the increasing number of treatment options available for multiple myeloma, relapse is still inevitable and there remains a critical unmet need for treatments for patients with late-stage, highly refractory disease. In this review, we discuss currently approved treatment options for heavily pretreated patients with relapsed and refractory multiple myeloma, with a focus on the optimal management of patients with MM refractory to lenalidomide, bortezomib, and in some cases, daratumumab or an anti-CD38 monoclonal antibody. Data from recent clinical trials of immunomodulatory agents (pomalidomide), proteasome inhibitors (PIs; carfilzomib and ixazomib), monoclonal antibodies (elotuzumab, daratumumab, and isatuximab), and other novel therapies (including panobinostat-based therapy) are summarized. We also provide potential therapeutic strategies for patients according to different treatment histories, and include case studies to illustrate the practical use of various treatment options in a clinical setting. Regimens containing pomalidomide, elotuzumab, next-generation PIs, panobinostat, or selinexor may provide effective treatment options in patients with triple-refractory disease. The choice of agents used, and combinations thereof should be individualized as well as strategically planned from early- to late-stage relapse.

Identification of New Antibodies Targeting Malignant Plasma Cells for Immunotherapy by Next-Generation Sequencing-Assisted Phage Display

To identify new antibodies for the treatment of plasma cell disorders including multiple myeloma (MM), a single-chain Fragment variable (scFv) antibody library was generated by immunizing mice with patient-derived malignant plasma cells. To enrich antibodies binding myeloma antigens, phage display with cellular panning was performed. After depleting the immune library with leukocytes of healthy donors, selection of antibodies was done with L-363 plasma cell line in two consecutive panning rounds. Monitoring the antibodies' enrichment throughout the panning by next-generation sequencing (NGS) identified several promising candidates. Initially, 41 unique scFv antibodies evolving from different B cell clones were selected. Nine of these antibodies strongly binding to myeloma cells and weakly binding to peripheral blood mononuclear cells (PBMC) were characterized. Using stably transfected Chinese hamster ovary cells expressing individual myeloma-associated antigens revealed that two antibodies bind CD38 and intercellular adhesion molecule-1 (ICAM-1), respectively, and 7 antibodies target yet unknown antigens. To evaluate the therapeutic potential of our new antibodies, in a first proof-of-concept study the CD38 binding scFv phage antibody was converted into a chimeric IgG1. Further analyses revealed that #5-CD38-IgG1 shared an overlapping epitope with daratumumab and isatuximab and had potent anti-myeloma activity comparable to the two clinically approved CD38 antibodies. These results indicate that by phage display and deep sequencing, new antibodies with therapeutic potential for MM immunotherapy can be identified.

Exposure‐response analyses for selection/confirmation of optimal isatuximab dosing regimen in combination with pomalidomide/dexamethasone treatment in patients with multiple myeloma

Isatuximab is an approved anti‐CD38 monoclonal antibody with multiple antitumor modes of action. An exposure‐response (E‐R) analysis using data from patients with relapsed/refractory multiple myeloma (RRMM) enrolled in a phase Ib clinical study who received isatuximab at doses from 5 to 20 mg/kg weekly for 1 cycle (4 weeks) followed by every 2 weeks thereafter (qw/q2w) in combination with pomalidomide/dexamethasone (n = 44) was first used to determine the optimal dose/schedule for the phase III ICARIA‐MM study. It was complemented by an E‐R analysis from a second phase Ib study of patients who received isatuximab at doses from 3 to 10 mg/kg q2w or 10 or 20 mg/kg qw/q2w in combination with lenalidomide/dexamethasone (n = 52). Plasma trough concentration at week 4 (CT4W) was the best predictor for response, and the benefit of the initial 4‐weekly administration was confirmed. Although the predicted overall response rate (ORR) was higher at 20 mg/kg vs. 10 mg/kg, the 95% confidence intervals were overlapping. Considering the high probability of success to reach the targeted ORR of greater than or equal to 60%, 10 mg/kg qw/q2w was selected. Results of the E‐R analysis from the lenalidomide/dexamethasone study and published disease modeling using data from both phase Ib clinical studies reinforced 10 mg/kg qw/q2w as the optimal dose/schedule for the phase III ICARIA‐MM study. E‐R analysis showed that higher CT4W was associated with higher ORR. Developed models supported the phase III isatuximab dosing regimen selection/confirmation of 10 mg/kg qw/q2w for use in combination with pomalidomide/dexamethasone in patients with RRMM.

SAR442085, a novel anti-CD38 antibody with enhanced antitumor activity against multiple myeloma

Anti-CD38 monoclonal antibodies (mAbs) represent a breakthrough in the treatment of multiple myeloma (MM), yet some patients fail to respond or progress quickly with this therapy, highlighting the need for novel approaches. In this study we compared the preclinical efficacy of SAR442085, a next-generation anti-CD38 mAb with enhanced affinity for activating Fcγ receptors (FcγR), with first-generation anti-CD38 mAb daratumumab and isatuximab. In surface plasmon resonance and cellular binding assays, we found that SAR442085 had higher binding affinity than daratumumab and isatuximab for FcγRIIa (CD32a) and FcγRIIIa (CD16a). SAR442085 also exhibited better in vitro antibody-dependent cellular cytotoxicity (ADCC) against a panel of MM cells expressing variable CD38 receptor densities including MM patients' primary plasma cells. The enhanced ADCC of SAR442085 was confirmed using NK-92 cells bearing low and high affinity FcγRIIIa (CD16a)-158F/V variants. Using MM patients' primary bone marrow cells, we confirmed that SAR442085 had an increased ability to engage FcγRIIIa, resulting in higher natural killer (NK) cell activation and degranulation against primary plasma cells than preexisting Fc wild-type anti-CD38 mAbs. Finally, using huFcgR transgenic mice that express human Fcγ receptors under the control of their human regulatory elements, we demonstrated that SAR442085 had higher NK cell-dependent in vivo antitumor efficacy and better survival than daratumumab and isatuximab against EL4 thymoma or VK*MYC myeloma cells overexpressing human CD38. These results highlight the preclinical efficacy of SAR442085 and support the current evaluation of this next-generation anti-CD38 antibody in phase I clinical development in patients with relapsed/refractory MM.

Outcomes of anti-CD38 isatuximab plus pomalidomide and dexamethasone in five relapsed myeloma patients with prior exposure to anti-C38 daratumumab: case series

Objectives: Daratumumab is the first anti-CD38 monoclonal antibody (Mab) used to treat myeloma in the newly diagnosed setting and in the relapsed setting. Isatuximab, another Mab targeting a specific epitope on the CD38 receptor, was recently approved in the UK in combination with pomalidomide and dexamethasone (IsaPomDex) to treat myeloma patients who received three prior lines of therapy. However, there is a lack of understanding of whether using a prior anti-CD38 Mab (e.g. daratumumab) can affect the efficacy of another Mab (e.g. isatuximab), when the latter is used to treat a subsequent relapse.Methods: We performed a UK-wide outcomes study of IsaPomDex in the real-world. In this case series, we report a detailed descriptive analysis of the characteristics and clinical outcomes of five IsaPomDex patients in UK routine practice (Patients I to V), with a prior exposure to daratumumab.Results: Age range was 51-77 years with two patients >70 and three patients <70 years. The cytogenetic risk was standard in two patients, high in two patients and not known in one patient. Prior daratumumab regimen were monotherapy (dara-mono) in one patient (II), and daratumumab with bortezomib and dexamethasone (DVd) in four patients. Responses to prior daratumumab were: very good partial response (VGPR) in two patients (I and III), minor response-stable disease (MR-SD) in one patient (II), and progressive disease (PD) in two patients (IV and V). Median (range) number of IsaPomDex cycles received was 2 (1-4). Outcomes of IsaPomDex were PD in three patients (II, IV and V) and a response in two patients. Response categories were: MR-SD in patient I and PR in patient III.Discussion: Despite the limitations of our case series, we described the first UK real-world report of IsaPomDex outcomes in myeloma patients with a prior exposure to daratumumab.Conclusion: Large prospective studies are required to further evaluate myeloma outcomes in this setting.

Isatuximab monotherapy in patients with refractory T-acute lymphoblastic leukemia or T-lymphoblastic lymphoma: Phase 2 study

The poor prognosis of acute T‐cell lymphoblastic leukemia (T‐ALL) and T‐cell lymphoblastic lymphoma (T‐LBL) in older adults and patients with relapsed/refractory illness is an unmet clinical need, as there is no defined standard of care and there are few treatment options. Abnormally elevated CD38 expression in T‐ALL and T‐LBL is associated with tumor expansion and disease development, making CD38 a potential target for anti‐T‐ALL and T‐LBL treatment. Isatuximab is a monoclonal antibody that binds to a specific epitope on CD38. The purpose of the study was to assess the efficacy and safety of isatuximab monotherapy in a phase 2, multicenter, one‐arm, open‐label study in patients with relapsed or refractory T‐ALL or T‐LBL (Clinical Trials.gov identifier NCT02999633). The primary endpoint was to assess the efficacy of isatuximab by overall response rate (ORR). An interim analysis based on the efficacy and safety of isatuximab in the first 19 patients enrolled was scheduled, however only 14 patients were enrolled in the study. No patient achieved complete response (CR) or CR with incomplete peripheral recovery. Most patients (11 [78.6%]) developed progressive disease and had progressive disease as their best response. A total of 10 (71.4%) patients had treatment emergent adverse events considered treatment‐related, with infusion reactions as the most frequent drug‐related TEAE, occurring in 8 (57.1%) patients. Despite the low efficacy of isatuximab in the current study, it is likely that the use of immunotherapy medication in T‐ALL will be expanded through logically targeted approaches, together with advances in the design of T‐cell therapy and clinical experience and will provide restorative options beyond chemotherapy and targeted treatments.

Isatuximab in the Treatment of Multiple Myeloma: A Review and Comparison With Daratumumab

Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of clonal plasma cells. Although advances in treatment have markedly improved survival outcomes for patients with MM, this disease is still considered incurable owing to its high incidence of relapse and refractoriness. Isatuximab is an anti-CD38 monoclonal antibody that can induce apoptosis in myeloma cells through a variety of mechanisms. Many clinical studies have demonstrated the efficacy and efficiency of isatuximab in both relapsed/refractory multiple myeloma (RRMM) and newly diagnosed multiple myeloma, leading to its approval for the treatment of adults with RRMM in combination therapies. In this review, the structure, mechanisms of action, pharmacokinetics, pharmacogenetics, and safety profile of isatuximab in MM are summarized. Additionally, isatuximab is compared with daratumumab in terms of mechanism and efficacy.

TNB-738, a biparatopic antibody, boosts intracellular NAD+ by inhibiting CD38 ecto-enzyme activity

Cluster of differentiation 38 (CD38) is an ecto-enzyme expressed primarily on immune cells that metabolize nicotinamide adenine dinucleotide (NAD+) to adenosine diphosphate ribose or cyclic ADP-ribose and nicotinamide. Other substrates of CD38 include nicotinamide adenine dinucleotide phosphate and nicotinamide mononucleotide, a critical NAD+ precursor in the salvage pathway. NAD+ is an important coenzyme involved in several metabolic pathways and is a required cofactor for the function of sirtuins (SIRTs) and poly (adenosine diphosphate-ribose) polymerases. Declines in NAD+ levels are associated with metabolic and inflammatory diseases, aging, and neurodegenerative disorders. To inhibit CD38 enzyme activity and boost NAD+ levels, we developed TNB-738, an anti-CD38 biparatopic antibody that pairs two non-competing heavy chain-only antibodies in a bispecific format. By simultaneously binding two distinct epitopes on CD38, TNB-738 potently inhibited its enzymatic activity, which in turn boosted intracellular NAD+ levels and SIRT activities. Due to its silenced IgG4 Fc, TNB-738 did not deplete CD38-expressing cells, in contrast to the clinically available anti-CD38 antibodies, daratumumab, and isatuximab. TNB-738 offers numerous advantages compared to other NAD-boosting therapeutics, including small molecules, and supplements, due to its long half-life, specificity, safety profile, and activity. Overall, TNB-738 represents a novel treatment with broad therapeutic potential for metabolic and inflammatory diseases associated with NAD+ deficiencies.Abbreviations: 7-AAD: 7-aminoactinomycin D; ADCC: antibody dependent cell-mediated cytotoxicity; ADCP: antibody dependent cell-mediated phagocytosis; ADPR: adenosine diphosphate ribose; APC: allophycocyanin; cADPR: cyclic ADP-ribose; cDNA: complementary DNA; BSA: bovine serum albumin; CD38: cluster of differentiation 38; CDC: complement dependent cytotoxicity; CFA: Freund's complete adjuvant; CHO: Chinese hamster ovary; CCP4: collaborative computational project, number 4; COOT: crystallographic object-oriented toolkit; DAPI: 4',6-diamidino-2-phenylindole; DNA: deoxyribonucleic acid; DSC: differential scanning calorimetry; 3D: three dimensional; εNAD+: nicotinamide 1,N₆-ethenoadenine dinucleotide; ECD: extracellular domain; EGF: epidermal growth factor; FACS: fluorescence activated cell sorting; FcγR: Fc gamma receptors; FITC: fluorescein isothiocyanate; HEK: human embryonic kidney; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IgG: immunoglobulin; IFA: incomplete Freund's adjuvant; IFNγ: Interferon gamma; KB: kinetic buffer; kDa: kilodalton; KEGG: kyoto encyclopedia of genes and genomes; LDH: lactate dehydrogenase; M: molar; mM: millimolar; MFI: mean fluorescent intensity; NA: nicotinic acid; NAD: nicotinamide adenine dinucleotide; NADP: nicotinamide adenine dinucleotide phosphate; NAM: nicotinamide; NGS: next-generation sequencing; NHS/EDC: N-Hydroxysuccinimide/ ethyl (dimethylamino propyl) carbodiimide; Ni-NTA: nickel-nitrilotriacetic acid; nL: nanoliter; NK: natural killer; NMN: nicotinamide mononucleotide; OD: optical density; PARP: poly (adenosine diphosphate-ribose) polymerase; PBS: phosphate-buffered saline; PBMC: peripheral blood mononuclear cell; PDB: protein data bank; PE: phycoerythrin; PISA: protein interfaces, surfaces, and assemblies: PK: pharmacokinetics; mol: picomolar; RNA: ribonucleic acid; RLU: relative luminescence units; rpm: rotations per minute; RU: resonance unit; SEC: size exclusion chromatography; SEM: standard error of the mean; SIRT: sirtuins; SPR: surface plasmon resonance; µg: microgram; µM: micromolar; µL: microliter.

Efficacy and safety of daratumumab combined with all-trans retinoic acid in relapsed/refractory multiple myeloma

The efficacy of daratumumab depends partially on CD38 expression on multiple myeloma (MM) cells. We have previously shown that all-trans retinoic acid (ATRA) upregulates CD38 expression and reverts daratumumab-resistance ex vivo. We therefore evaluated the optimal dose, efficacy, and safety of daratumumab combined with ATRA in patients with daratumumab-refractory MM in a phase 1/2 study (NCT02751255). In part A of the study, 63 patients were treated with daratumumab monotherapy. Fifty patients with daratumumab-refractory MM were subsequently enrolled in part B and treated with daratumumab (reintensified schedule) combined with ATRA until disease progression. The recommended phase 2 dose of ATRA in combination with daratumumab was defined as 45 mg/m2. At this dose, the overall response rate (ORR) was 5%, indicating that the primary endpoint (ORR ≥15%) was not met. However, most patients (66%) achieved at least stable disease. After a median follow-up of 43 months, the median progression-free survival (PFS) for all patients was 2.8 months. Patients who previously achieved at least a partial response or minimal response/stable disease with prior daratumumab monotherapy had a significantly longer PFS compared with patients who immediately progressed during daratumumab as single agent (median PFS 3.4 and 2.8 vs 1.3 months). The median overall survival was 19.1 months. The addition of ATRA did not increase the incidence of adverse events. Flow cytometric analysis revealed that ATRA temporarily increased CD38 expression on immune cell subsets. In conclusion, the addition of ATRA and reintensification of daratumumab had limited activity in patients with daratumumab-refractory MM, which may be explained by the transient upregulation of CD38 expression. This trial was registered at www.clinicaltrials.gov as #NCT02751255.

Promising Antigens for the New Frontier of Targeted Immunotherapy in Multiple Myeloma

Simple Summary

Defining the specificity and biological sequalae induced by receptors differentiated expressed in multiple myeloma cells are critical for the development of effective immunotherapies based on monoclonal antibodies. Ongoing studies continue to discover new antigens with superior tumor selectivity and defined function in regulating the pathophysiology of myeloma cells directly or indirectly in the immunosuppressive bone marrow microenvironment. Meanwhile, it is urgent to identify mechanisms of immune resistance and design more potent immunotherapies, alone and/or with best combination partners to further prolong anti-MM immunity.

Abstract

The incorporation of novel agents in recent treatments in multiple myeloma (MM) has improved the clinical outcome of patients. Specifically, the approval of monoclonal antibody (MoAb) against CD38 (daratumumab) and SLAMF7 (elotuzumab) in relapsed and refractory MM (RRMM) represents an important milestone in the development of targeted immunotherapy in MM. These MoAb-based agents significantly induce cytotoxicity of MM cells via multiple effector-dependent mechanisms and can further induce immunomodulation to repair a dysfunctional tumor immune microenvironment. Recently, targeting B cell maturation antigen (BCMA), an even MM-specific antigen, has shown high therapeutic activities by chimeric antigen receptor T cells (CAR T), antibody-drug conjugate (ADC), bispecific T-cell engager (BiTE), as well as bispecific antibody (BiAb), with some already approved for heavily pretreated RRMM patients. New antigens, such as orphan G protein-coupled receptor class C group 5 member D (GPRC5D) and FcRH5, were identified and rapidly moved to ongoing clinical studies. We here summarized the pathobiological function of key MM antigens and the status of the corresponding immunotherapies. The potential challenges and emerging treatment strategies are also discussed.

Isatuximab: Nursing Considerations for Use in the Treatment of Multiple Myeloma

BACKGROUND

Isatuximab is a CD38 monoclonal antibody approved for use in combination with pomalidomide plus dexamethasone to treat adults with relapsed/refractory multiple myeloma who have received at least two prior therapies. Because isatuximab is a relatively new treatment option, published guidelines for oncology nurses are limited.

OBJECTIVES

This article provides nurses with guidance on all aspects of isatuximab administration and patient management to better support those receiving this treatment.

METHODS

Data from the ICARIA-MM (NCT02990338) clinical trial and additional nursing resources were collected and condensed into concise treatment and management recommendations for the care of patients with multiple myeloma undergoing treatment with isatuximab.

FINDINGS

Nursing care of patients prescribed isatuximab includes monitoring of clinical and laboratory parameters and requires knowledge and management of associated adverse events, including infusion reactions and neutropenia. This information could aid oncology nurses in providing optimal, treatment-specific education to patients and caregivers.

Current and prospective antibody-based therapies in multiple myeloma

Multiple Myeloma (MM) is a hematologic malignancy involving clonal plasma cell proliferation. Unfortunately, MM remains an incurable disease. Over the past five years, the incorporation of novel monoclonal antibodies has synergized with standard of care to improve patient outcomes in both newly diagnosed MM as well as relapsed and refractory MM. This manuscript reviews current and prospective antibody-based treatments including naked monoclonal antibodies, immunoconjugates, and Bi-specific T-cell engagers (BiTE).

Treatment Strategy for Multiple Myeloma to Improve Immunological Environment and Maintain MRD Negativity

Improving the immunological environment and eradicating minimal residual disease (MRD) are the two main treatment goals for long-term survival in patients with multiple myeloma (MM). Immunomodulatory drugs (IMiDs), monoclonal antibody drugs (MoAbs), and autologous grafts for autologous stem cell transplantation (ASCT) can improve the immunological microenvironment. ASCT, MoAbs, and proteasome inhibitors (PIs) may be important for the achievement of MRD negativity. An improved immunological environment may be useful for maintaining MRD negativity, although the specific treatment for persistent MRD negativity is unknown. However, whether the ongoing treatment should be continued or changed if the MRD status remains positive is controversial. In this case, genetic, immunophenotypic, and clinical analysis of residual myeloma cells may be necessary to select the effective treatment for the residual myeloma cells. The purpose of this review is to discuss the MM treatment strategy to "cure MM" based on currently available therapies, including IMiDs, PIs, MoAbs, and ASCT, and expected immunotherapies, such as chimeric antigen receptor T cell (CAR-T) therapy, via improvement of the immunological environment and maintenance of MRD negativity.

Isatuximab, carfilzomib and dexamethasone (Isa-Kd) for the management of relapsed multiple myeloma

The treatment of relapsed multiple myeloma remains challenging. Based on interim data from the randomized Phase III IKEMA study demonstrating a progression-free survival benefit with a combination of isatuximab (Isa, a CD38-targeted monoclonal antibody) and carfilzomib/dexamethasone (Kd) versus Kd alone, Isa-Kd recently received regulatory approval in the USA and Europe for patients with multiple myeloma who have received at least one prior line of therapy (in the USA, up to three prior lines). In this review we discuss the rationale and clinical trial experience to date with Isa-Kd. Although final IKEMA results are pending, Isa-Kd has emerged as an effective and tolerable therapy for patients with relapsed multiple myeloma. Given the growing number of antibody-containing triplet regimens in this setting, potential niches and limitations for Isa-Kd are also discussed.

Isatuximab for relapsed/refractory multiple myeloma: review of key subgroup analyses from the Phase III ICARIA-MM study

In the Phase III ICARIA-MM study (NCT02990338), the addition of the anti-CD38 monoclonal antibody isatuximab to pomalidomide and dexamethasone led to increased progression-free survival and improved response rates in patients with relapsed/refractory multiple myeloma. There is an unmet treatment need, particularly among patients with poor prognoses, including those with high-risk cytogenetics, those who have renal impairment, those who are elderly and those who are refractory to prior lines of treatment. In this review, the subgroup analyses from the ICARIA-MM study, representing subpopulations with poor prognostic factors, are discussed. Overall, the addition of isatuximab to pomalidomide and dexamethasone improved progression-free survival and disease response rates across different subgroups, regardless of prognostic factor.

Isatuximab: A Review of Its Use in Multiple Myeloma

Isatuximab (Sarclisa®; isatuximab-irfc in the USA) is an anti-CD38 monoclonal antibody (mAb) approved for use in the treatment of adults with multiple myeloma (MM): in combination with pomalidomide and dexamethasone for those with relapsed and refractory MM (RRMM) who have received ≥ 2 prior therapies, including lenalidomide and a proteasome inhibitor; and in combination with carfilzomib and dexamethasone for those with relapsed MM who have received ≥ 1 prior therapy. In phase III studies, the addition of isatuximab to pomalidomide and dexamethasone significantly prolonged progression-free survival (PFS) and improved the depth of tumour response in patients with RRMM, as did the addition of isatuximab to carfilzomib and dexamethasone in patients with relapsed or refractory MM. Health-related quality of life was maintained when isatuximab was combined with these other therapies. Isatuximab-based combination therapies were generally well tolerated and demonstrated a manageable safety profile with no new safety signals. Although mature overall survival data are awaited, available evidence indicates that the combinations of isatuximab with pomalidomide and dexamethasone and isatuximab with carfilzomib and dexamethasone are important additional treatment options for RRMM and relapsed MM, respectively.

Evaluation of Preclinical Activity of Isatuximab in Patients with Acute Lymphoblastic Leukemia

This study reports the pharmacologic effects of isatuximab, a CD38 mAb, on T- and B-cell acute lymphoblastic leukemia (ALL). We analyzed CD38 expression in 50-T-ALL and 50 B-ALL clinical samples, and 16 T-ALL and 11 B-ALL cell lines. We primarily focused on in vitro assessments of isatuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). In vivo assessment of isatuximab activity was performed in several ALL xenograft models, including disseminated and subcutaneous tumor models in female C.B-17 severe combined immunodeficiency mice. Our study reveals that most patients (90%-100%) carried CD38⁺ blasts independent of disease burden. The median CD38 receptor density on abnormal lymphoblasts is 41,026 copies/cell on T-ALL and 28,137 copies/cell on B-ALL, respectively. In patients with T-ALL, there is a significant increase of CD38 expression in abnormal blasts compared with normal T cells. High-level CD38 receptor density (RD) is critical to trigger effective isatuximab-mediated ADCC against target ALL cells. In addition, a correlation between CD38 RD and isatuximab-mediated ADCP is demonstrated. In the disseminated CD38⁺, T-ALL, and B-ALL xenograft models, isatuximab is able to induce robust antitumor activity, even at low doses. This study shows that isatuximab has significant in vitro and in vivo activity against ALL cells with robust ADCC and ADCP effects that are associated with CD38 expression levels in both T-ALL and B-ALL.

Crosslinking of CD38 Receptors Triggers Apoptosis of Malignant B Cells

Recently, we designed an inventive paradigm in nanomedicine—drug-free macromolecular therapeutics (DFMT). The ability of DFMT to induce apoptosis is based on biorecognition at cell surface, and crosslinking of receptors without the participation of low molecular weight drugs. The system is composed of two nanoconjugates: a bispecific engager, antibody or Fab’ fragment—morpholino oligonucleotide (MORF1) conjugate; the second nanoconjugate is a multivalent effector, human serum albumin (HSA) decorated with multiple copies of complementary MORF2. Here, we intend to demonstrate that DFMT is a platform that will be effective on other receptors than previously validated CD20. We appraised the impact of daratumumab (DARA)- and isatuximab (ISA)-based DFMT to crosslink CD38 receptors on CD38+ lymphoma (Raji, Daudi) and multiple myeloma cells (RPMI 8226, ANBL-6). The biological properties of DFMTs were determined by flow cytometry, confocal fluorescence microscopy, reactive oxygen species determination, lysosomal enlargement, homotypic cell adhesion, and the hybridization of nanoconjugates. The data revealed that the level of apoptosis induction correlated with CD38 expression, the nanoconjugates meet at the cell surface, mitochondrial signaling pathway is strongly involved, insertion of a flexible spacer in the structure of the macromolecular effector enhances apoptosis, and simultaneous crosslinking of CD38 and CD20 receptors increases apoptosis.

LRRK2 is required for CD38-mediated NAADP-Ca2+ signaling and the downstream activation of TFEB (transcription factor EB) in immune cells

CD38 is a cell surface receptor capable of generating calcium-mobilizing second messengers. It has been implicated in host defense and cancer biology, but signaling mechanisms downstream of CD38 remain unclear. Mutations in LRRK2 (leucine-rich repeat kinase 2) are the most common genetic cause of Parkinson disease; it is also a risk factor for Crohn disease, leprosy, and certain types of cancers. The pathogenesis of these diseases involves inflammation and macroautophagy/autophagy, processes both CD38 and LRRK2 are implicated in. Here, we mechanistically and functionally link CD38 and LRRK2 as upstream activators of TFEB (transcription factor EB), a host defense transcription factor and the master transcriptional regulator of the autophagy/lysosome machinery. In B-lymphocytes and macrophages, we show that CD38 and LRRK2 exist in a complex on the plasma membrane. Ligation of CD38 with the monoclonal antibody clone 90 results in internalization of the CD38-LRRK2 complex and its targeting to the endolysosomal system. This generates an NAADP-dependent calcium signal, which requires LRRK2 kinase activity, and results in the downstream activation of TFEB. lrrk2 KO macrophages accordingly have TFEB activation defects following CD38 or LPS stimulation and fail to switch to glycolytic metabolism after LPS treatment. In overexpression models, the pathogenic LRRK2^G2019S mutant promotes hyperactivation of TFEB even in the absence of CD38, both by stabilizing TFEB and promoting its nuclear translocation via aberrant calcium signaling. In sum, we have identified a physiological CD38-LRRK2-TFEB signaling axis in immune cells. The common pathogenic mutant, LRRK2^G2019S, appears to hijack this pathway.

Abbreviations:ADPR: ADP-ribose; AMPK: AMP-activated protein kinase; BMDM: bone marrow-derived macrophage; cADPR: cyclic-ADP-ribose; COR: C-terminal of ROC; CTSD: cathepsin D; ECAR: extracellular acidification rate; EDTA: ethylenediaminetetraacetic acid; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; GPN: Gly-Phe β-naphthylamide; GSK3B/GSK3β: glycogen synthase kinase 3 beta; GTP: guanosine triphosphate; KD: knockdown; LAMP1: lysosomal-associated membrane protein 1; LRR: leucine rich repeat; LRRK2: leucine rich repeat kinase 2; mAb: monoclonal antibody; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAPK/ERK: mitogen-activated protein kinase; MCOLN1: mucolipin 1; MFI: mean fluorescence intensity; mRNA: messenger RNA; MTOR: mechanistic target of rapamycin kinase; NAADP: nicotinic acid adenine dinucleotide phosphate; NAD: nicotinamide adenine dinucleotide; NADP: nicotinamide adenine dinucleotide phosphate; PD: Parkinson disease; PPP3CB: protein phosphatase 3, catalytic subunit, beta isoform; q-RT-PCR: quantitative reverse transcription polymerase chain reaction; ROC: Ras of complex; siRNA: small interfering RNA; SQSTM1/p62: sequestome 1; TFEB: transcription factor EB; TPCN: two pore channel; TRPM2: transient receptor potential cation channel, subfamily M, member 2; ZKSCAN3: zinc finger with KRAB and SCAN domains 3

BCMA-Specific ADC MEDI2228 and Daratumumab Induce Synergistic Myeloma Cytotoxicity via IFN-Driven Immune Responses and Enhanced CD38 Expression

PURPOSE

Efforts are required to improve the potency and durability of CD38- and BCMA-based immunotherapies in human multiple myeloma. We here delineated the molecular and cellular mechanisms underlying novel immunomodulatory effects triggered by BCMA pyrrolobenzodiazepine (PBD) antibody drug conjugate (ADC) MEDI2228 which can augment efficacy of these immunotherapies.

EXPERIMENTAL DESIGN

MEDI2228-induced transcriptional and protein changes were investigated to define significantly impacted genes and signaling cascades in multiple myeloma cells. Mechanisms whereby MEDI2228 combination therapies can enhance cytotoxicity or overcome drug resistance in multiple myeloma cell lines and patient multiple myeloma cells were defined using in vitro models of tumor in the bone marrow (BM) microenvironment, as well as in human natural killer (NK)-reconstituted NOD/SCID gamma (NSG) mice bearing MM1S tumors.

RESULTS

MEDI2228 enriched IFN I signaling and enhanced expression of IFN-stimulated genes in multiple myeloma cell lines following the induction of DNA damage-ATM/ATR-CHK1/2 pathways. It activated cGAS-STING-TBK1-IRF3 and STAT1-IRF1-signaling cascades and increased CD38 expression in multiple myeloma cells but did not increase CD38 expression in BCMA-negative NK effector cells. It overcame CD38 downregulation on multiple myeloma cells triggered by IL6 and patient BM stromal cell-culture supernatant via activation of STAT1-IRF1, even in immunomodulatory drug (IMiD)- and bortezomib-resistant multiple myeloma cells. In vitro and in vivo upregulation of NKG2D ligands and CD38 in MEDI2228-treated multiple myeloma cells was further associated with synergistic daratumumab (Dara) CD38 MoAb-triggered NK-mediated cytotoxicity of both cell lines and autologous drug-resistant patient multiple myeloma cells.

CONCLUSIONS

These results provide the basis for clinical evaluation of combination MEDI2228 with Dara to further improve patient outcome in multiple myeloma.

Individualized genetic makeup that controls natural killer cell function influences the efficacy of isatuximab immunotherapy in patients with multiple myeloma

BACKGROUND

Phase IIb clinical trial with isatuximab (Isa)-lenalidomide (Len)-dexamethasone (Dex) showed an improved progression-free survival (PFS) in patients with relapsed or refractory multiple myeloma (RRMM), but the efficacy varied by patient. Antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) cells plays a crucial role in arbitrating antitumor activities of therapeutic-antibodies. We tested if patient-specific genetic makeup known to set NK cell functional threshold influence response to Isa-Len-Dex therapy.

METHODS

We characterized 57 patients with RRMM receiving Isa-Len-Dex for polymorphisms of killer-cell immunoglobulin-like receptors (KIR), human leukocyte antigen (HLA) class I, and FCGR3A loci. In vitro ADCC assay, coincubating primary NK cells expressing specific KIR repertoire with multiple myeloma cell lines (MM cells) expressing selected HLA class I ligands, was used to confirm the identified genetic correlatives of clinical response.

RESULTS

Patients with KIR3DL2+ and its cognate-ligand HLA-A3/11+ had superior PFS than patients missing this combination (HR=0.43; p=0.02), while patients carrying KIR2DL1+ and HLA-C2C2+ compared with to patients missing this pair showed short PFS (HR=3.54; p=0.05). Patients with KIR3DL2+ and HLA-A3/11+ plus high-affinity FCGR3A-158V allele showed the most prolonged PFS (HR=0.35; p=0.007). Consistent with these clinical data, mechanistic experiments demonstrated that NK cells expressing KIR3DL2 trigger greater ADCC when MM cells express HLA-A3/11. Inversely, NK cells expressing KIR2DL1 do not kill if MM cells express the HLA-C2C2 ligand. NK cells expressing high-affinity FCGR3A-158VV-induced greater ADCC compared with those with low-affinity FCGR3A-158FF.

CONCLUSIONS

Our results suggest that KIR3DL2+ and HLA-A3/11+ with FCGR3A-158V markers lead to enhanced Isa-dependent NK-mediated cytolysis against MM cells and results in improved PFS in patients with RRMM treated by Isa-Len-Dex. Moreover, the presence of KIR2DL1+ and HLA-C2C2+ identifies patients who may have a lower response to Isa-Len-Dex therapy linked to a reduced NK-mediated ADCC. These biomarkers could potentially identify, via precision medicine, patients more likely to respond to Isa-Len-Dex immunotherapy.

TRIAL REGISTRATION NUMBER

NCT01749969.

Stromal Cells Serve Drug Resistance for Multiple Myeloma via Mitochondrial Transfer: A Study on Primary Myeloma and Stromal Cells

Simple Summary

Mitochondrial transfer plays a crucial role in the acquisition of drug resistance in multiple myeloma, but its exact mechanism is not yet clear; moreover, overcoming the drug resistance that it causes is also a major challenge. Our research on primary myeloma cell cultures reveals that mitochondrial transfer is bi-directional between bone marrow stromal cells and myeloma cells, occurring via tunneling nanotubes and partial cell fusion with extreme increases under the influence of chemotherapeutic drugs, whereupon survival and adenosine triphosphate levels increase, while mitochondrial superoxide levels decrease in myeloma cells. These changes and the elevation of superoxide levels in stromal cells are proportional to the amount of incorporated mitochondria derived from the other cell type and to the concentration of the used drug. Although the inhibition of mitochondrial transfer is limited between stromal and myeloma cells, the supportive effect of stromal cells can be effectively averted by influencing the tumor metabolism with an inhibitor of oxidative phosphorylation in addition to chemotherapeutics.

Abstract

Recently, it has become evident that mitochondrial transfer (MT) plays a crucial role in the acquisition of cancer drug resistance in many hematologic malignancies; however, for multiple myeloma, there is a need to generate novel data to better understand this mechanism. Here, we show that primary myeloma cells (MMs) respond to an increasing concentration of chemotherapeutic drugs with an increase in the acquisition of mitochondria from autologous bone marrow stromal cells (BM-MSCs), whereupon survival and adenosine triphosphate levels of MMs increase, while the mitochondrial superoxide levels decrease in MMs. These changes are proportional to the amount of incorporated BM-MSC-derived mitochondria and to the concentration of the used drug, but seem independent from the type and mechanism of action of chemotherapeutics. In parallel, BM-MSCs also incorporate an increasing amount of MM cell-derived mitochondria accompanied by an elevation of superoxide levels. Using the therapeutic antibodies Daratumumab, Isatuximab, or Elotuzumab, no similar effect was observed regarding the MT. Our research shows that MT occurs via tunneling nanotubes and partial cell fusion with extreme increases under the influence of chemotherapeutic drugs, but its inhibition is limited. However, the supportive effect of stromal cells can be effectively avoided by influencing the metabolism of myeloma cells with the concomitant use of chemotherapeutic agents and an inhibitor of oxidative phosphorylation.

Mechanisms of Action of the New Antibodies in Use in Multiple Myeloma

Monoclonal antibodies (mAbs) directed against antigen-specific of multiple myeloma (MM) cells have Fc-dependent immune effector mechanisms, such as complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP), but the choice of the antigen is crucial for the development of effective immuno-therapy in MM. Recently new immunotherapeutic options in MM patients have been developed against different myeloma-related antigens as drug conjugate-antibody, bispecific T-cell engagers (BiTEs) and chimeric antigen receptor (CAR)-T cells. In this review, we will highlight the mechanism of action of immuno-therapy currently available in clinical practice to target CD38, SLAMF7, and BCMA, focusing on the biological role of the targets and on mechanisms of actions of the different immunotherapeutic approaches underlying their advantages and disadvantages with critical review of the literature data.

PK/PD modeling analysis for dosing regimen selection of isatuximab as single agent and in combination therapy in patients with multiple myeloma

This analysis describes the pharmacokinetic/pharmacodynamic (PK/PD) modeling framework that supported selection of the isatuximab (anti‐CD38 monoclonal antibody) dosing regimen alongside its early clinical development in patients with relapsed/refractory multiple myeloma (RRMM). The PK/PD mathematical model characterized the variations of patient serum M‐protein concentrations, the primary marker of tumor burden in multiple myeloma (MM). Three separate PK/PD models were built sequentially as data became available from phase I clinical trials. The primary PK/PD analysis was initiated using monotherapy phase I study data (n = 122), followed by analysis of data collected from phase Ib combination studies with lenalidomide and dexamethasone (Rd, n = 40) and then with pomalidomide and dexamethasone (Pd, n = 31). Using the PK/PD model, abnormal “myeloma” protein (M‐protein) profiles under different isatuximab dosing regimens were simulated. Overall, simulations revealed that regimens which included a loading period of four weekly administrations followed by administration every 2 weeks thereafter (QW4‐Q2W), reduced M‐protein levels more than a Q2W regimen without a loading period. For isatuximab monotherapy, a 20 mg/kg dose induced greater reduction in serum M‐protein levels compared with doses equal or lower than 10 mg/kg. For isatuximab in combination with either Rd or Pd, simulations yielded no substantial benefit in terms of M‐protein reduction between isatuximab 10 mg/kg and 20 mg/kg. These PK/PD analyses supported the use of isatuximab 10 mg/kg QW4‐Q2W in combination with Pd in the phase III trial.

EMA Review of Isatuximab in Combination with Pomalidomide and Dexamethasone for the Treatment of Adult Patients with Relapsed and Refractory Multiple Myeloma

Isatuximab is a monoclonal antibody that binds to the human CD38 antigen. On May 30, 2020, a marketing authorization valid through the European Union (EU) was issued for isatuximab in combination with pomalidomide and dexamethasone (IsaPd) for the treatment of adult patients with relapsed and refractory (RR) multiple myeloma (MM). The recommended dose of isatuximab was 10 mg/kg, administered intravenously weekly at cycle 1 and then biweekly in subsequent 28-day cycles. Isatuximab was evaluated in a phase III, open-label, multicenter, randomized trial that randomly allocated IsaPd versus pomalidomide plus dexamethasone (Pd) to adult patients with RR MM. The primary endpoint of the trial was progression-free survival, as assessed by an independent review committee, which was superior for the IsaPd arm (hazard ratio, 0.596; 95% confidence interval, 0.436-0.814; p = .001) compared with the Pd arm. Treatment with IsaPd led to higher incidences of treatment-related adverse events (AEs), grade ≥ 3 AEs, and serious AEs compared with Pd treatment. Most frequently observed AEs that occurred more often in the IsaPd arm were infusion-related reactions, infections, respiratory AEs, neutropenia (including neutropenic complications), and thrombocytopenia. The aim of this article is to summarize the scientific review of the application leading to regulatory approval in the EU. IMPLICATIONS FOR PRACTICE: Isatuximab was approved in the European Union, in combination with pomalidomide and dexamethasone, for the treatment of patients with multiple myeloma who have already received therapy but whose disease did not respond or relapsed afterward. The addition of isatuximab resulted in a clinically meaningful and significant prolongation of the time from treatment initiation to further disease relapse or patient's death. The safety profile was considered acceptable, and the benefit-risk ratio was determined to be positive.

Isatuximab, carfilzomib, and dexamethasone in relapsed multiple myeloma (IKEMA): a multicentre, open-label, randomised phase 3 trial

BACKGROUND

Isatuximab is an anti-CD38 monoclonal antibody approved in combination with pomalidomide-dexamethasone and carfilzomib-dexamethasone for relapsed or refractory multiple myeloma. This phase 3, open-label study compared the efficacy of isatuximab plus carfilzomib-dexamethasone versus carfilzomib-dexamethasone in patients with relapsed multiple myeloma.

METHODS

This was a prospective, randomised, open-label, parallel-group, phase 3 study done at 69 study centres in 16 countries across North America, South America, Europe, and the Asia-Pacific region. Patients with relapsed or refractory multiple myeloma aged at least 18 years who had received one to three previous lines of therapy and had measurable serum or urine M-protein were eligible. Patients were randomly assigned (3:2) to isatuximab plus carfilzomib-dexamethasone (isatuximab group) or carfilzomib-dexamethasone (control group). Patients in the isatuximab group received isatuximab 10 mg/kg intravenously weekly for the first 4 weeks, then every 2 weeks. Both groups received the approved schedule of intravenous carfilzomib and oral or intravenous dexamethasone. Treatment continued until progression or unacceptable toxicity. The primary endpoint was progression-free survival and was assessed in the intention-to-treat population according to assigned treatment. Safety was assessed in all patients who received at least one dose according to treatment received. The study is registered at ClinicalTrials.gov, NCT03275285.

FINDINGS

Between Nov 15, 2017, and March 21, 2019, 302 patients with a median of two previous lines of therapy were enrolled. 179 were randomly assigned to the isatuximab group and 123 to the control group. Median progression-free survival was not reached in the isatuximab group compared with 19·15 months (95% CI 15·77-not reached) in the control group, with a hazard ratio of 0·53 (99% CI 0·32-0·89; one-sided p=0·0007). Treatment-emergent adverse events (TEAEs) of grade 3 or worse occurred in 136 (77%) of 177 patients in the isatuximab group versus 82 (67%) of 122 in the control group, serious TEAEs occurred in 105 (59%) versus 70 (57%) patients, and TEAEs led to discontinuation in 15 (8%) versus 17 (14%) patients. Fatal TEAEs during study treatment occurred in six (3%) versus four (3%) patients.

INTERPRETATION

The addition of isatuximab to carfilzomib-dexamethasone significantly improves progression-free survival and depth of response in patients with relapsed multiple myeloma, representing a new standard of care for this patient population.

FUNDING

Sanofi. VIDEO ABSTRACT.

Emerging New Approaches in Desensitization: Targeted Therapies for HLA Sensitization

There is an urgent need for therapeutic interventions for desensitization and antibody-mediated rejection (AMR) in sensitized patients with preformed or de novo donor-specific HLA antibodies (DSA). The risk of AMR and allograft loss in sensitized patients is increased due to preformed DSA detected at time of transplant or the reactivation of HLA memory after transplantation, causing acute and chronic AMR. Alternatively, de novo DSA that develops post-transplant due to inadequate immunosuppression and again may lead to acute and chronic AMR or even allograft loss. Circulating antibody, the final product of the humoral immune response, has been the primary target of desensitization and AMR treatment. However, in many cases these protocols fail to achieve efficient removal of all DSA and long-term outcomes of patients with persistent DSA are far worse when compared to non-sensitized patients. We believe that targeting multiple components of humoral immunity will lead to improved outcomes for such patients. In this review, we will briefly discuss conventional desensitization methods targeting antibody or B cell removal and then present a mechanistically designed desensitization regimen targeting plasma cells and the humoral response.

Rapid Progress in Immunotherapies for Multiple Myeloma: An Updated Comprehensive Review

Despite rapid advances in treatment approaches of multiple myeloma (MM) over the last two decades via proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and monoclonal antibodies (mAbs), their efficacies are limited. MM still remains incurable, and the majority of patients shortly relapse and eventually become refractory to existing therapies due to the genetic heterogeneity and clonal evolution. Therefore, the development of novel therapeutic strategies with different mechanisms of action represents an unmet need to achieve a deep and highly durable response as well as to improve patient outcomes. The antibody-drug conjugate (ADC), belanatmab mafadotin, which targets B cell membrane antigen (BCMA) on plasma cells, was approved for the treatment of MM in 2020. To date, numerous immunotherapies, including bispecific antibodies, such as bispecific T cell engager (BiTE), the duobody adoptive cellular therapy using a dendritic cell (DC) vaccine, autologous chimeric antigen (CAR)-T cells, allogeneic CAR-natural killer (NK) cells, and checkpoint inhibitors have been developed for the treatment of MM, and a variety of clinical trials are currently underway or are expected to be planned. In the future, the efficacy of combination approaches, as well as allogenic CAR-T or NK cell therapy, will be examined, and promising results may alter the treatment paradigm of MM. This is a comprehensive review with an update on the most recent clinical and preclinical advances with a focus on results from clinical trials in progress with BCMA-targeted immunotherapies and the development of other novel targets in MM. Future perspectives will also be discussed.

Final results of a phase 1b study of isatuximab short-duration fixed-volume infusion combination therapy for relapsed/refractory multiple myeloma

Part B of this phase 1b study (ClinicalTrials.gov number, NCT02283775) evaluated safety and efficacy of a fixed-volume infusion of isatuximab, an anti-CD38 monoclonal antibody, in combination with pomalidomide and dexamethasone (Pd) in relapsed/refractory multiple myeloma patients. Isatuximab (10 mg/kg weekly for 4 weeks, then every other week) was administered as a fixed-volume infusion of 250 mL (mL/h infusion rate) with standard doses of Pd on 28-day cycles. Patients (N = 47) had a median of three prior treatment lines (range, 1-8). Median duration of exposure was 36.9 weeks and median duration of first, second, and 3+ infusions were 3.7, 1.8, and 1.2 h, respectively. The most common non-hematologic treatment-emergent adverse events were fatigue (63.8%), infusion reactions (IRs), cough, and upper respiratory tract infection (40.4% each). IRs were all grade 2 and occurred only during the first infusion. The overall response rate was 53.2% in all patients (55.5% in response-evaluable population, 60.0% in daratumumab-naïve patients). Efficacy and safety findings were consistent with data from the isatuximab plus Pd infusion schedule in Part A of this study and also from the phase 3 ICARIA-MM study, and these new data confirm the safety, efficacy, and feasibility of fixed-volume infusion of isatuximab.

Subgroup analysis of ICARIA-MM study in relapsed/refractory multiple myeloma patients with high-risk cytogenetics

Treatment benefit in multiple myeloma (MM) patients with high‐risk cytogenetics remains suboptimal. The phase 3 ICARIA‐MM trial (NCT02990338) showed that isatuximab plus pomalidomide–dexamethasone prolongs median progression‐free survival (mPFS) in patients with relapsed/refractory MM (RRMM). This subgroup analysis of ICARIA‐MM compared the benefit of isatuximab in high‐risk [defined by the presence of del(17p), t(4;14) or t(14;16)] versus standard‐risk patients. The efficacy of isatuximab in patients with gain(1q21) abnormality was also assessed in a retrospective subgroup analysis. In ICARIA‐MM, 307 patients received isatuximab–pomalidomide–dexamethasone (n = 154) or pomalidomide–dexamethasone (n = 153). Isatuximab (10 mg/kg intravenously) was given weekly in the first 28‐day cycle, and every other week thereafter. Standard pomalidomide–dexamethasone doses were given. Isatuximab–pomalidomide–dexamethasone improved mPFS (7·5 vs 3·7 months; HR, 0·66; 95% CI, 0·33–1·28) and overall response rate (ORR, 50·0% vs 16·7%) in high‐risk patients. In patients with isolated gain(1q21), isatuximab addition improved mPFS (11·2 vs 4·6 months; HR, 0·50; 95% CI, 0·28–0·88) and ORR (53·6% vs 27·6%). More grade ≥3 adverse events occurred in high‐risk patients receiving isatuximab (95·7%) versus the control group (67·6%); however, isatuximab did not increase events leading to discontinuation or treatment‐related mortality. Isatuximab–pomalidomide–dexamethasone provides a consistent benefit over pomalidomide–dexamethasone treatment in RRMM patients regardless of cytogenetic risk.

An evaluation of isatuximab, pomalidomide and dexamethasone for adult patients with relapsed and refractory multiple myeloma

INTRODUCTION

Despite therapeutic advances, myeloma remains an essentially incurable disease, with a median survival of approximately 8 - 10 years. Most patients will develop disease that is refractory to immunomodulatory agents (IMiDs) and proteasome inhibitors (PIs), and treatment regimens containing drugs with different mechanisms of action are necessary. Isatuximab is one such novel agent, an anti-CD38 monoclonal antibody (MoAb), and is the second drug in this class after daratumumab. This paper will consider the current role for isatuximab with pomalidomide for the treatment of relapsed/refractory myeloma (RRMM).

AREAS COVERED

This review provides an overview of the pharmacological characteristics of isatuximab, and its clinical development including safety and efficacy data to date.

EXPERT OPINION

Isatuximab in combination with pomalidomide and dexamethasone offers a new treatment option for those patients with RRMM who are refractory to PIs and lenalidomide, a patient group with poor prognosis and unmet clinical need. The challenge of where it is best placed in the treatment algorithm remains, particularly with the increasing application of daratumumab particularly in the front- and second-line settings.

Evolution of Treatment Paradigms in Newly Diagnosed Multiple Myeloma

The plasma cell neoplasm multiple myeloma (MM) is currently considered incurable. However, significant advances in treatment options over the past 20 years have led to unprecedented response rates to initial therapy as well as prolonged survival rates. Induction regimens have evolved from alkylator-based therapies to those consisting of immunomodulatory drugs and proteasome inhibitors. The combination of bortezomib/lenalidomide/dexamethasone (VRd) has emerged as a standard regimen for both transplant-eligible (TE) and transplant-ineligible (TI) patient populations. More recent efforts have focused on the incorporation of monoclonal antibody therapy into the newly diagnosed setting, particularly anti-CD38 monoclonal antibodies. In the TI patient population, the combination of daratumumab/lenalidomide/dexamethasone is now considered another standard therapy. In the TE setting, it remains to be determined whether the addition of daratumumab to the VRd backbone results in improved long-term outcomes. Recent studies have confirmed the progression-free survival benefit of upfront autologous stem cell transplant and have established lenalidomide maintenance as a standard of care. Multiple studies are evaluating whether inclusion of monoclonal antibody therapy in the maintenance setting will improve outcomes. The optimal management of newly diagnosed patients with high-risk cytogenetics remains to be determined. We discuss the emerging therapies that will likely shape management of newly diagnosed MM in the future.

A new decade: novel immunotherapies on the horizon for relapsed/refractory multiple myeloma

INTRODUCTION

Survival in multiple myeloma (MM) has improved due to the ongoing revolution of therapeutic approaches. Nevertheless, many patients relapse, and additional novel approaches are required to prolong remissions and prevent disease progression.

AREAS COVERED

Considering the success of monoclonal antibodies (mAbs) against CD38 and SLAMF7 in relapsed/refractory MM (R/R MM), additional antigens expressed on malignant plasma cells are being investigated as treatment targets. Among these, many trials are focusing on B cell maturation antigen (BCMA), using either antibody-drug conjugates (ADCs), bispecific T cell engagers (TCE), or chimeric antigen receptor T cells (CAR-T). Other potential targets include the myeloma markers CD138, GPRC5D, FcRH5, the plasma cell differentiating factors APRIL, TACI and BAFF, and the immune checkpoint proteins CD47 and TIGIT. Additionally, novel immunomodulatory Cereblon E3 Ligase Modulators (CELMoDs) offer the potential to overcome resistance to conventional immunomodulatory agents. Based upon PubMed and abstract searches primarily from the past 4 years, here we review the data supporting novel immunotherapies for R/R MM.

EXPERT OPINION

Overcoming disease resistance remains a challenge in R/R MM. Novel therapeutic approaches targeting MM antigens and/or enhancing immune cell function offer the potential to prolong survival and are actively being investigated in clinical trials.

Isatuximab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma according to prior lines of treatment and refractory status: ICARIA-MM subgroup analysis

Patients with relapsed/refractory multiple myeloma (RRMM) experience several relapses, and become refractory to successive therapies. In the ICARIA-MM trial (NCT02990338), isatuximab plus pomalidomide-dexamethasone prolonged median progression-free survival (PFS) in patients with RRMM. This subgroup analysis of ICARIA-MM assessed the treatment benefit of isatuximab by prior lines of therapy and refractory status. A total of 307 patients were randomized to isatuximab-pomalidomide-dexamethasone (n = 154) or pomalidomide-dexamethasone (n = 153). Isatuximab (10 mg/kg intravenously) was given weekly in the first 28-day cycle, then every other week. Standard pomalidomide-dexamethasone doses were given. PFS was assessed by prior lines and refractory status. Overall, 102 (66 %) patients receiving isatuximab-pomalidomide-dexamethasone and 101 (66 %) patients receiving pomalidomide-dexamethasone had received 2-3 prior lines; 52 (34 %) and 52 (34 %) had received >3 prior lines, respectively. Median PFS was higher with isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone for patients who received 2-3 prior lines of therapy (12.3 vs. 7.8 months) and >3 prior lines of therapy (9.4 vs. 4.3 months). Median PFS was higher with isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone for patients who were lenalidomide-refractory (11.4 vs. 5.6 months), lenalidomide-refractory at last line (11.6 vs. 5.7 months), refractory to a proteasome inhibitor (PI) (11.4 vs. 5.6 months), and double-refractory (11.2 vs. 4.8 months). Overall response rate (ORR) in patients receiving isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone was 59.0 % versus 31.4 % in lenalidomide-refractory; 60.2 % versus 32.2 % in PI-refractory; and 58.6 % versus 29.9 % in double-refractory patients. Isatuximab-pomalidomide-dexamethasone improved PFS and ORR regardless of prior lines of therapy or refractory status, consistent with the benefit in the overall population.

Isatuximab for the treatment of relapsed/refractory multiple myeloma

INTRODUCTION

Although new drug classes have significantly extended survival of patients with multiple myeloma, they continue to experience multiple relapses and/or become refractory to treatment. Therefore, novel therapies and treatment combinations with different mechanisms of action are needed to improve the outcomes of patients with relapsed/refractory multiple myeloma.

AREAS COVERED

Here, the authors review the published data regarding the development and clinical investigation of isatuximab, a CD38 monoclonal antibody, for treatment of patients with relapsed/refractory multiple myeloma. The mechanisms of action, clinical efficacy, and safety of isatuximab treatment are summarized.

EXPERT OPINION

Isatuximab is approved in combination with pomalidomide/dexamethasone for the treatment of adults with relapsed/refractory multiple myeloma who have received at least two prior therapies, including lenalidomide and a proteasome inhibitor. Isatuximab displays a manageable safety profile, with infusion reactions being the most common adverse events. Isatuximab is currently being further evaluated in combination with other backbone regimens in relapsed/refractory and newly diagnosed multiple myeloma.

Immune System Alterations in Multiple Myeloma: Molecular Mechanisms and Therapeutic Strategies to Reverse Immunosuppression

Simple Summary

A common characteristic of multiple myeloma (MM) is the dysfunction of patients’ immune system, a condition termed immunosuppression. This state is mainly due to alterations in the number and functionality of the principal immune populations. In this setting, immunotherapy has acquired high relevance in the last years and the investigation of agents that boost the immune system represent a field of interest. In the present review, we will summarize the main cellular and molecular alterations observed in MM patients’ immune system. Furthermore, we will describe the mechanisms of action of the four immunotherapeutic drugs approved so far for the treatment of MM, which are part of the group of monoclonal antibodies (mAbs). Finally, the immune-stimulating effects of several therapeutic agents are described due to their potential role in reversing immunosuppression and, therefore, in favoring the efficacy of immunotherapy drugs, such as mAbs, as part of future pharmacological combinations.

Abstract

Immunosuppression is a common feature of multiple myeloma (MM) patients and has been associated with disease evolution from its precursor stages. MM cells promote immunosuppressive effects due to both the secretion of soluble factors, which inhibit the function of immune effector cells, and the recruitment of immunosuppressive populations. Alterations in the expression of surface molecules are also responsible for immunosuppression. In this scenario, immunotherapy, as is the case of immunotherapeutic monoclonal antibodies (mAbs), aims to boost the immune system against tumor cells. In fact, mAbs exert part of their cytotoxic effects through different cellular and soluble immune components and, therefore, patients’ immunosuppressive status could reduce their efficacy. Here, we will expose the alterations observed in symptomatic MM, as compared to its precursor stages and healthy subjects, in the main immune populations, especially the inhibition of effector cells and the activation of immunosuppressive populations. Additionally, we will revise the mechanisms responsible for all these alterations, including the interplay between MM cells and immune cells and the interactions among immune cells themselves. We will also summarize the main mechanisms of action of the four mAbs approved so far for the treatment of MM. Finally, we will discuss the potential immune-stimulating effects of non-immunotherapeutic drugs, which could enhance the efficacy of immunotherapeutic treatments.

Boosting Immunity against Multiple Myeloma

Despite the improvement of patient's outcome obtained by the current use of immunomodulatory drugs, proteasome inhibitors or anti-CD38 monoclonal antibodies, multiple myeloma (MM) remains an incurable disease. More recently, the testing in clinical trials of novel drugs such as anti-BCMA CAR-T cells, antibody-drug conjugates or bispecific antibodies broadened the possibility of improving patients' survival. However, thus far, these treatment strategies have not been able to steadily eliminate all malignant cells, and the aim has been to induce a long-term complete response with minimal residual disease (MRD)-negative status. In this sense, approaches that target not only myeloma cells but also the surrounding microenvironment are promising strategies to achieve a sustained MRD negativity with prolonged survival. This review provides an overview of current and future strategies used for immunomodulation of MM focusing on the impact on bone marrow (BM) immunome.

Isatuximab as monotherapy and combined with dexamethasone in patients with relapsed/refractory multiple myeloma

This phase 2 study evaluated isatuximab as monotherapy or combined with dexamethasone in relapsed/refractory multiple myeloma (RRMM). Patients had RRMM refractory to an immunomodulatory drug (IMiD) and a proteasome inhibitor (PI) or had received ≥3 prior lines of therapy incorporating an IMiD and PI. Patients received isatuximab either as monotherapy (20 mg/kg on days 1, 8, 15, and 22 [once weekly] of cycle 1 followed by 20 mg/kg on days 1 and 15 of subsequent cycles; Isa group) or in combination with dexamethasone (40 mg/d [20 mg/d in patients aged ≥75 years] once weekly; Isa-dex group). Treated patients (N = 164) had received a median of 4 (range, 2-10) prior treatment lines. Patients received a median of 5 (1-24) and 7 (1-22) treatment cycles; at data cutoff, 13 (11.9%) of 109 and 15 (27.3%) of 55 patients remained on treatment in the Isa and Isa-dex arms, respectively. Overall response rate (primary efficacy end point) was 23.9% in the Isa arm and 43.6% in the Isa-dex arm (odds ratio, 0.405; 95% confidence interval, 0.192-0.859; P = .008). Median progression-free survival and overall survival were 4.9 and 18.9 months for Isa, and 10.2 and 17.3 months for Isa-dex. Infusion reactions (mostly grade 1/2) and hematologic abnormalities were the most common adverse events. There was a similar incidence of grade 3 or higher infections in both groups (22.0% and 21.8%). In conclusion, addition of dexamethasone to isatuximab increased response rates and survival outcomes with no detrimental effect on safety. This trial was registered at www.clinicaltrials.gov as #NCT01084252.

Isatuximab plus pomalidomide and dexamethasone in relapsed/refractory multiple myeloma patients with renal impairment: ICARIA-MM subgroup analysis

The randomized, phase 3 ICARIA-MM study investigated isatuximab (Isa) with pomalidomide and dexamethasone (Pd) versus Pd in patients with relapsed/refractory multiple myeloma and ≥2 prior lines. This prespecified subgroup analysis examined efficacy in patients with renal impairment (RI; estimated glomerular filtration rate <60 mL/min/1.73 m²). Isa 10 mg/kg was given intravenously once weekly in cycle 1, and every 2 weeks in subsequent 28-day cycles. Patients received standard doses of Pd. Median progression-free survival (PFS) for patients with RI was 9.5 months with Isa-Pd (n = 55) and 3.7 months with Pd (n = 49; hazard ratio [HR] 0.50; 95% confidence interval [CI], 0.30-0.85). Without RI, median PFS was 12.7 months with Isa-Pd (n = 87) and 7.9 months with Pd (n = 96; HR 0.58; 95% CI, 0.38-0.88). The overall response rate (ORR) with and without RI was higher with Isa-Pd (56 and 68%) than Pd (25 and 43%). Complete renal response rates were 71.9% (23/32) with Isa-Pd and 38.1% (8/21) with Pd; these lasted ≥60 days in 31.3% (10/32) and 19.0% (4/21) of patients, respectively. Isa pharmacokinetics were comparable between the subgroups, suggesting no need for dose adjustment in patients with RI. In summary, the addition of Isa to Pd improved PFS, ORR and renal response rates.

Harnessing the Immune System Against Multiple Myeloma: Challenges and Opportunities

Multiple myeloma (MM) is an incurable malignancy of plasma cells that grow within a permissive bone marrow microenvironment (BMM). The bone marrow milieu supports the malignant transformation both by promoting uncontrolled proliferation and resistance to cell death in MM cells, and by hampering the immune response against the tumor clone. Hence, it is expected that restoring host anti-MM immunity may provide therapeutic benefit for MM patients. Already several immunotherapeutic approaches have shown promising results in the clinical setting. In this review, we outline recent findings demonstrating the potential advantages of targeting the immunosuppressive bone marrow niche to restore effective anti-MM immunity. We discuss different approaches aiming to boost the effector function of T cells and/or exploit innate or adaptive immunity, and highlight novel therapeutic opportunities to increase the immunogenicity of the MM clone. We also discuss the main challenges that hamper the efficacy of immune-based approaches, including intrinsic resistance of MM cells to activated immune-effectors, as well as the protective role of the immune-suppressive and inflammatory bone marrow milieu. Targeting mechanisms to convert the immunologically “cold” to “hot” MM BMM may induce durable immune responses, which in turn may result in long-lasting clinical benefit, even in patient subgroups with high-risk features and poor survival.

IFN-γ and CD38 in Hyperprogressive Cancer Development

Immune checkpoint inhibitors (ICIs) improve the survival of patients with multiple types of cancer. However, low response rates and atypical responses limit their success in clinical applications. The paradoxical acceleration of tumor growth after treatment, defined as hyperprogressive disease (HPD), is the most difficult problem facing clinicians and patients alike. The mechanisms that underlie hyperprogression (HP) are still unclear and controversial, although different factors are associated with the phenomenon. In this review, we propose two factors that have not yet been demonstrated to be directly associated with HP, but upon which it is important to focus attention. IFN-γ is a key cytokine in antitumor response and its levels increase during ICI therapy, whereas CD38 is an alternative immune checkpoint that is involved in immunosuppressive responses. As both factors are associated with resistance to ICI therapy, we have discussed their possible involvement in HPD with the conclusion that IFN-γ may contribute to HP onset through the activation of the inflammasome pathway, immunosuppressive enzyme IDO1 and activation-induced cell death (AICD) in effector T cells, while the role of CD38 in HP may be associated with the activation of adenosine receptors, hypoxia pathways and AICD-dependent T-cell depletion.

Sequential CD38 monoclonal antibody retreatment leads to deep remission in a patient with relapsed/refractory multiple myeloma

We report on a currently 76-year-old female patient with relapsed/refractory (RR) multiple myeloma (MM) treated at our institution. This patient had received six lines of therapy including tandem autologous stem cell transplant, proteasome inhibitor, immunomodulatory drugs and CD38 antibody MOR202. At the last relapse, she progressed during treatment with pomalidomide and MOR202. In an individualized therapy concept, we started a multi-agent salvage therapy with pomalidomide, bortezomib, doxorubicin, dexamethasone, and CD38 antibody daratumumab (“Pom-PAD-Dara”), which resulted in a stringent complete remission with minimal residual disease (MRD) negativity after nine cycles. So far, our patient shows a progression free survival of more than 12 months. Our case demonstrates the feasibility of successful CD38 antibody retreatment in a patient with heavily pretreated CD38 antibody resistant MM.

VIS832, a novel CD138-targeting monoclonal antibody, potently induces killing of human multiple myeloma and further synergizes with IMiDs or bortezomib in vitro and in vivo

Therapeutically targeting CD138, a define multiple myeloma (MM) antigen, is not yet approved for patients. We here developed and determined the preclinical efficacy of VIS832, a novel therapeutic monoclonal antibody (MoAb) with differentiated CD138 target binding to BB4 that is anti-CD138 MoAb scaffold for indatuximab ravtansine (BT062). VIS832 demonstrated enhanced CD138-binding avidity and significantly improved potency to kill MM cell lines and autologous patient MM cells regardless of resistance to current standard-of-care therapies, via robust antibody-dependent cellular cytotoxicity and phagocytosis mediated by NK and macrophage effector cells, respectively. Specifically, CD38-targeting daratumumab-resistant MM cells were highly susceptible to VIS832 which, unlike daratumumab, spares NK cells. Superior maximal cytolysis of VIS832 vs. daratumumab corresponded to higher CD138 vs. CD38 levels in MM cells. Furthermore, VIS832 acted synergistically with lenalidomide or bortezomib to deplete MM cells. Importantly, VIS832 at a sub-optimal dose inhibited disseminated MM1S tumors in vivo as monotherapy (P < 0.0001), and rapidly eradicated myeloma burden in all mice concomitantly receiving bortezomib, with 100% host survival. Taken together, these data strongly support clinical development of VIS832, alone and in combination, for the therapeutic treatment of MM in relapsed and refractory patients while pointing to its potential therapeutic use earlier in disease intervention.

Drug-Disease Interaction and Time-Dependent Population Pharmacokinetics of Isatuximab in Relapsed/Refractory Multiple Myeloma Patients

Isatuximab, a monoclonal antibody (mAb) of immunoglobulin G (IgG) isotype, specifically targets the cluster of differentiation 38 antigen overexpressed in malignant plasma cells. Isatuximab is used to treat multiple myeloma (MM), characterized by the excessive production of abnormal "myeloma proteins" (M-proteins) that may interact with therapeutic IgG mAb on the neonatal Fc receptor (FcRn)-mediated recycling pathway. The clinical pharmacology profile of isatuximab was investigated by population pharmacokinetics (PKs) modeling in 476 patients with MM who received 1-20 mg/kg isatuximab either as single agent or in combination with pomalidomide-dexamethasone in 4 clinical trials. Isatuximab PKs were characterized by a two-compartment model with parallel time-varying linear clearance (CL) and nonlinear elimination. Due to a mechanism-based drug-disease interaction, patients secreting IgG M-protein exhibited a twofold lower drug exposure compared with patients with non-IgG MM. No dose adjustment was required based on MM immunoglobulin type because efficacy and safety profiles were comparable between IgG and non-IgG MM subpopulations. β2-microglobulin, body weight, sex, drug material, and race have a limited effect on drug exposure and do not require any dose adjustment. A typical 50% decrease in linear CL from initial treatment to steady-state was predicted, and this decrease correlated with the best overall response rate and was slower for patients with IgG MM. These findings suggest that the time-dependent effect of isatuximab is likely mediated by a combined factor of both disease state evolution and the perturbation of the FcRn-mediated recycling pathway.