CD38 antibody re-treatment in daratumumab-refractory multiple myeloma after time on other therapies

Impact of social determinants of health on treatment patterns and outcomes in multiple myeloma

AIMS

Evaluate treatment and outcomes by social determinants of health (SDoH) in multiple myeloma (MM), which are important for improving care and outcomes.

METHODS

This was a retrospective study of real-world patients enrolled in a US insurance claims database (MM diagnosis, July 2018-December 2022) with linkage to a SDoH database, supplemented with mortality, provider affiliation (academic/community), and socioeconomically disadvantaged area databases. Treatment and outcomes were evaluated across SDoH domains: race/ethnicity, education level, transportation access, food insecurity, risky health behaviors, living in disadvantaged areas, healthcare needs, and ease of healthcare-systems engagement.

RESULTS

The study included 4768 patients (2295 and 2731 with care-setting and treatment data); median follow-up, 584 days. Patients treated in academic versus community settings were less likely to be food insecure and live in disadvantaged areas and had lower healthcare needs. Stem cell transplant was more common in White versus non-White patients, those with low versus high food insecurity and healthcare needs, and high versus low ease of healthcare-systems engagement. In multivariable analysis, high versus low disadvantaged areas (HR = 1.75) and medium versus low food insecurity (HR = 1.80) were associated with shorter overall survival.

CONCLUSIONS

These findings indicate a need for improved access to care in the broader MM population.

Novel drug combinations for newly diagnosed multiple myeloma: how can we improve on current regimens?

INTRODUCTION

Multiple myeloma (MM) therapy has greatly evolved over the last decade. Immunomodulators and anti-CD38 antibodies have reshaped the therapeutic landscape. Nevertheless, relapses occur with worsening prognosis each relapse. Achieving deep responses in first-line treatment is key to reducing future disease burden.

AREAS COVERED

To advance patient outcomes, current regimens must be continuously refined through personalization, incorporation of biomarkers to guide therapy, and novel drugs. This review aims to assess existing therapies and investigate how integrating novel drug combinations and biomarker-driven approaches can improve efficacy and tolerability for newly diagnosed multiple myeloma (NDMM) patients. Meta-analysis, systematic reviews, original articles, and real-world studies were included in this review. Databases searched included PubMed, Scopus, and Google Scholar from inception until February 2025.

EXPERT OPINION

Discerning the best therapy sequence is a challenge for NDMM individuals. Minimal residual disease assessment is becoming a pivotal tool for guiding therapeutic approaches to enhance outcomes and tolerability. Emerging evidence supports early use of potent therapies - such as next-generation anti-CD38 antibodies and CELMoDs - to achieve deeper, more durable responses and possibly delay relapses. Immunotherapies like bispecific antibodies and CAR-T cells are also being explored in front-line settings, though reducing their infectious complications is still under investigation.

A systematic review and meta-analysis of phase III randomized controlled trials to assess the risk of pneumonia, URTIs, and VTE in multiple myeloma patients treated with isatuximab

Background

Multiple myeloma (MM) is a hematologic malignancy characterized by the clonal proliferation of malignant plasma cells in the bone marrow, constituting approximately 13% of all hematologic malignancies. Isatuximab is a monoclonal antibody targeting the CD38 protein on myeloma cells, causing cell death through various immune-mediated mechanisms. Clinical trials have shown that adding isatuximab to standard regimens for MM significantly enhances efficacy but introduces some notable toxicities. The purpose of this study is to determine the risk of pneumonia, upper respiratory tract infections (URTIs), and venous thromboembolism (VTE) in patients with MM treated with isatuximab.

Methods

We conducted a comprehensive literature search using Medline, Embase, and Cochrane databases from inception through July 22nd, 2024. Phase III randomized controlled trials (RCTs) utilizing isatuximab in newly diagnosed MM (NDMM) and relapsed and refractory MM (RRMM) reporting pneumonia, URTIs, and VTE as adverse events were included. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was assessed with Cochran's Q-statistic. Random effects model was applied.

Results

A total of 1,044 patients from three phase III RCTs (ICARIA-MM, IKEMA, IMROZ) were included for pneumonia and URTI analysis, while 1,403 patients from three trials (IKEMA, IMROZ, GMMG-HD7) were included for VTE evaluation. The incidence of any-grade pneumonia was higher in the isatuximab group (30.1% vs. 23.2%; RR, 1.31; 95% CI 1.06-1.61; P = 0.01), as was high-grade pneumonia (20.8% vs. 15.3%; RR, 1.38; 95% CI 1.06-1.81; P = 0.02). No statistically significant differences were observed between the isatuximab and control groups for any-grade URTIs, high-grade URTIs, or VTE.

Discussion

This meta-analysis highlights a significant increase in the incidence of pneumonia with the addition of isatuximab to standard myeloma regimens, underscoring the need for routine antibiotic prophylaxis, thromboprophylaxis, vigilant monitoring and early intervention to mitigate these risks.

Clinical outcomes associated with anti-CD38-based retreatment in relapsed/refractory multiple myeloma: a systematic literature review

Introduction

Anti-CD38-based therapy has become a backbone regimen for the treatment of multiple myeloma (MM), approved in first-, second-, and third-line settings. The effectiveness of anti-CD38-based retreatment after an initial relapse on previous anti-CD38-based therapy is unclear. Here we present the results of a systematic literature review investigating the clinical outcomes of anti-CD38-based retreatment in patients with relapsed/refractory MM.

Methods

Medline/Embase, congress publications, and other sources were searched (to December 8, 2023) for relevant articles in English and screened for eligibility criteria using the Population, Intervention, Comparator, Outcomes, Study Design (PICOS) framework, and data were then extracted for outcomes including progression-free survival (PFS), overall survival (OS), and overall response rate (ORR).

Results

In total, 2938 records were identified from the initial Medline/Embase search and 11 were identified from other sources; 34 were eligible for inclusion, representing 24 studies (6 clinical [n=18-307] and 18 real-world evidence [RWE; n=19-583]). Where reported, median follow-up ranged from 1.9-43.0 months across 6 clinical and 8.7-53.0 months across 10 RWE studies. For clinical trials, anti-CD38-based retreatment resulted in a median PFS of 1.0-2.8 months in all but one trial (19.4 months), a median OS of 10.7-19.1 months (not reached in one trial), and ORRs of 0-75%. RWE studies reported a median PFS of 1.5-8.4 months, a median OS of 8.4-19.0 months (not reached in one study), and ORRs of 24.6-90.0%.

Discussion

Findings from this systematic literature review indicate that clinical outcomes with anti-CD38-based retreatment are variable and offer limited clinical benefit in patients with relapsed/refractory MM, including in those refractory to anti-CD38-based treatment.

Efficacy and Prognostic Indicators of Isatuximab, Pomalidomide, and Dexamethasone (IsaPd) in Daratumumab-Refractory Multiple Myeloma Patients: A Multicenter Real-World Study

This multicenter real-world analysis evaluated the efficacy of isatuximab, pomalidomide, and dexamethasone (IsaPd) in 51 patients with multiple myeloma (MM) who were refractory to daratumumab (Dara-R). The majority were under 70 years old (60.8%), predominantly female (56.9%), and heavily pretreated, with 74.5% being triple-class refractory (TCR); 32.1% of the 28 patients with cytogenetic data had high-risk abnormalities. The overall response rate (ORR) was 56.9%, including 3 patients with stringent complete response (sCR), 4 with CR, and 7 with very good partial response (VGPR). Neither age, number of prior therapies, TCR status, nor time from Dara refractoriness to IsaPd initiation significantly affected response rates. Median progression-free survival (PFS) was 5.8 months, with a 12-month PFS probability of 30.6%. Baseline hemoglobin (Hb) levels were a key predictor of PFS: patients with Hb < 11.8 g/L had a 3.5-fold increased risk of progression, with a median PFS of 4.6 months compared to 22 months in those with higher Hb. Median overall survival (OS) was 21.0 months, with a 12-month OS probability of 63.4%. Lower Hb levels (< 11 g/L) were associated with a tenfold increased risk of mortality. Among the 28 patients who underwent FISH analysis, while no significant difference in mortality risk was observed, those with high-risk cytogenetic abnormalities exhibited a nearly tenfold increased risk of disease progression. These results suggest that IsaPd offers a meaningful option for Dara-R patients, with Hb levels serving as a critical predictor of both PFS and OS. However, PFS remains modest, underscoring the need for novel combination therapies.

Enhancing complement activation by therapeutic anti-tumor antibodies: Mechanisms, strategies, and engineering approaches

The complement system plays an integral role in both innate and adaptive immune responses. Beyond its protective function against infections, complement is also known to influence tumor immunity, where its activation can either promote tumor progression or mediate tumor cell destruction, depending on the context. One such context can be provided by antibodies, with their inherent capacity to activate the classical complement pathway. In recent years, our understanding of the mechanisms governing complement activation by IgG and IgM antibodies has expanded significantly. At the same time, preclinical and clinical studies on antibodies such as rituximab, ofatumumab, and daratumumab have provided evidence for the role of complement in therapeutic success, encouraging strategies to further enhance its activity. In this review we examine the main determinants of antibody-mediated complement activation, highlighting the importance of antibody subclass, affinity, valency, and geometry of antigen engagement. We summarize the evidence for complement involvement in anti-tumor activity and challenges of accurately estimating the extent of its contribution to therapeutic efficacy. Furthermore, we explore several engineering approaches designed to enhance complement activation, including increased Fc oligomerization and C1q affinity, bispecific C1q-recruiting antibodies, IgG subclass chimeras, as well as antibody and paratope combinations. Strategies targeting membrane-bound complement regulatory proteins to overcome tumor-associated complement inhibition are also discussed as a method to boost therapeutic efficacy. Finally, we highlight the potential of complement-dependent cellular cytotoxicity (CDCC) and complement-dependent cellular phagocytosis (CDCP) as effector mechanisms that warrant deeper investigation. By integrating advances in antibody and complement biology with insights from efforts to enhance complement activation in therapeutic antibodies, this review aims to provide a comprehensive framework of antibody design and engineering strategies that optimize complement activity for improved anti-tumor efficacy.

Response to daratumumab-retreatment in patients with multiple myeloma

Daratumumab is an effective therapy in multiple myeloma (MM). We assessed whether daratumumab retreatment may re-induce significant responses and which patients do benefit the most. We hypothesized, that there is effective synergism between daratumumab and alternating antimyeloma drug combinations during retreatment and that retreatment is safe and effective. Here, we analyzed 293 consecutive MM patients receiving daratumumab at our institution from 2016 until 2023 retrospectively, and compared responses, side effects and survival of the first daratumumab treatment line and its retreatment. We identified 22/293 (8%) patients with daratumumab retreatment. These patients showed an advanced age and ISS/R-ISS stages, and ≥ 3 lines of prior antimyeloma therapy in 91%. Of note, the median durations of the first and subsequent daratumumab treatment were similarly long. We confirmed a therapy break between daratumumab lines as advantageous. Daratumumab retreatment was effective, with responses declining only gradually from its first use to subsequent first and second retreatment with 64%, 46% and 43%, respectively. Interestingly, comparable progression free survival rates were observed with 11.5, 12 months and not reached, respectively. Consistently, adverse events per daratumumab line did not increase. Our findings suggest that well-selected daratumumab-exposed MM patients may show rewarding responses to daratumumab retreatment, the more with alternating antimyeloma combinations, initial good response and CD38-antibody-treatment pauses, thereby proving CD38-antibody-retreatment as feasible, effective and non-toxic. Confirmatory studies are required to further validate our results.

Clinical Efficacy of Isatuximab Plus Carfilzomib and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients

Isatuximab, a novel anti-CD38 monoclonal antibody, is approved in combination with carfilzomib and dexamethasone (Isa-Kd) in relapsed/refractory multiple myeloma (RRMM) patients. Because of its recent introduction, real-world efficacy and safety are poorly reported. In this Italian multicenter real-life observational retrospective study, efficacy and safety of the Isa-Kd regimen were evaluated in a cohort of 103 RRMM patients. Overall response rate (ORR) was 85%, with stringent (sCR) or complete response (CR) in 18% of cases and very good partial response (VGPR) in 39%. Median PFS and OS were not reached within the study period, while 1-year PFS and OS were 72% and 77%, respectively. Hematological toxicities were observed in 42% of subjects, and cardiac toxicities occurred in 24% of cases. Moreover, we conducted a subanalysis on patients (N = 69) treated with Isa-Kd after one prior line of therapy, showing an ORR of 88%, with sCR + CR in 20% of subjects, VGPR in 46%, and PR in 22% of patients. In this group, median PFS and OS were not reached, while 1-year PFS and OS were 92% and 95%, respectively. In conclusions, our study confirmed Isa-Kd as an effective treatment option for RRMM with a manageable safety profile even in real-life settings.

Retreatment of multiple myeloma with previously refractory drugs

ABSTRACT

As patients with relapsed/refractory multiple myeloma (RRMM) continue to live longer, they might get exposed to most available drugs and drug classes during the disease course. For such late line RRMM or among patients without access to novel therapies, retreatment with a drug that the disease had previously been refractory to might be one option. In this retrospective study, we describe 315 patients with RRMM at our institution who were retreated with a drug that the disease had been previously refractory to. We found an overall response rate of 56.2% and a median progression-free survival (PFS) of 11 months with retreatment. Patients with a longer time on initial therapy with the index drug (>28.4 months) had a superior PFS with retreatment (median PFS, 16.9 vs 8.1 months; P < .001). Similarly, patients with a longer time gap between the initial line of therapy with index drug and retreatment with index drug (>46.1 months) had better PFS with retreatment (28.2 vs 8.9 months; P = .016). In conclusion, retreatment with a previously refractory drug is a viable therapeutic option for RRMM, with the most significant benefit derived in disease demonstrating sensitivity to initial drug exposure and among those with a longer gap between initial drug exposure and retreatment.

A CD38/CD3xCD28 trispecific T-cell engager as a potentially active agent in multiple myeloma patients relapsed and/or refractory to anti-CD38 monoclonal antibodies

There is accumulating evidence of BCMA and GPRC5D loss after treatment with T-cell redirecting therapies in patients with relapsed/refractory multiple myeloma (RRMM). While complete CD38 loss is not observed upon relapses after treatment with anti-CD38 monoclonal antibodies (mAb), there is downregulation of surface CD38 expression and decreased number and function of NK cells, which renders these patients resistant to retreatment with anti-CD38 mAb. Here, we provide preclinical evidence that RRMM patients previously exposed to anti-CD38 mAb could benefit from T-cell-based immunotherapy that depend less on CD38 antigen density and NK-cell activity, such as the novel CD38/CD3xCD28 trispecific T-cell engager, SAR442257.

Chimeric antigen receptor T-cell therapy in autoimmune diseases

The administration of T cells that have been modified to carry chimeric antigen receptors (CARs) aimed at B cells has been an effective strategy in treating B cell malignancies. This breakthrough has spurred the creation of CAR T cells intended to specifically reduce or alter the faulty immune responses associated with autoimmune disorders. Early positive outcomes from clinical trials involving CAR T cells that target the B cell protein CD19 in patients suffering from autoimmune diseases driven by B cells have been reported. Additional strategies are being developed to broaden the use of CAR T cell therapy and enhance its safety in autoimmune conditions. These include employing chimeric autoantireceptors (CAAR) to specifically eliminate B cells that are reactive to autoantigens, and using regulatory T cells (Tregs) engineered to carry antigen-specific CARs for precise immune modulation. This discussion emphasizes key factors such as choosing the right target cell groups, designing CAR constructs, defining tolerable side effects, and achieving a lasting immune modification, all of which are critical for safely integrating CAR T cell therapy in treating autoimmune diseases.

An open-label, first-in-human, single agent, dose escalation study for the evaluation of safety and efficacy of SAR442085 in patients with relapsed or refractory multiple myeloma

OBJECTIVES

Cluster of differentiation 38 (CD38) is a key target on multiple myeloma (MM) cells. This multi-centre, Phase 1, single-agent study (NCT04000282) investigated SAR442085, a novel fragment crystallisable (Fc)-modified anti-CD38 monoclonal antibody (mAb), with enhanced affinity towards Fc-gamma receptor on effector cells in patients with relapsed and/or refractory (RR) MM.

METHODS

This study comprised two parts: Part-A (dose-escalation involving anti-CD38 mAb pre-treated and naïve patients) and Part-B (dose expansion). Primary endpoints were maximum tolerated dose and recommended Phase 2 dose (RP2D).

RESULTS

Thirty-seven heavily pre-treated patients were treated in Part A. Part-B (dose-expansion) was not studied. Seven dose-limiting toxicities were reported at DL3, DL5, DL6, and DL7. RP2D was determined to be 5-7·5 mg/kg. Most common treatment-emergent adverse events were infusion-related reactions in 70·3% (26/37) patients. Grade ≥3 thrombocytopenia was reported in 48·6% (18/37). Overall response rate was 70% in anti-CD38 mAb naïve and 4% in anti-CD38 pre-treated patients, with a median progression-free survival of 7·62 (95%CI: 2·858; not calculable) months and 2·79 (95%CI: 1·150; 4·172) months and, respectively.

CONCLUSIONS

The efficacy of SAR442085 was promising in anti-CD38 mAb naïve patients but did not extend to the larger cohort of anti-CD38 mAb pre-treated patients. This observation, along with transient high-grade thrombocytopenia, could potentially limit its clinical use.

Ex Vivo Efficacy of SAR442257 Anti-CD38 Trispecific T-cell Engager in Multiple Myeloma Relapsed After Daratumumab and BCMA-targeted Therapies

T cell-engaging antibodies (TCEs) are showing promising efficacy in relapsed/refractory multiple myeloma, even in patients that relapsed after B-cell maturation antigen (BCMA)-targeted therapy. Patients with multiple myeloma may have compromised T-cell health unaccounted for by preclinical models. Here, we use Myeloma Drug Sensitivity Testing (My-DST) for ex vivo measurement of anti-multiple myeloma cytotoxicity for the trispecific CD38/CD28xCD3 TCE SAR442257 through activation of the patients' own endogenous T cells to inform clinical development of the compound in multiple myeloma. My-DST incubates primary mononuclear cells in humanized media for 48 hours followed by flow cytometry for multiple myeloma cell viability with or without drug treatment. SAR442257 was tested on 34 samples from patients with multiple myeloma across disease settings. Potential biomarkers, T-cell dependence, and degranulation were assessed. SAR442257 was effective at low dose in My-DST cultures. High ex vivo response rates were observed in primary aspirates taken from patients with multiple myeloma at diagnosis, with modestly reduced response in multiple myeloma recently treated with anti-CD38 mAbs. SAR442257 was highly effective in patients relapsing after BCMA therapy. The CD38/CD28xCD3 trispecific format was substantially more effective than a conventional bispecific CD38/CD3 antibody format and CD38 mAbs. Anti-multiple myeloma cell cytotoxicity was dependent on the presence of endogenous T cells. Surface CD38 expression was the strongest biomarker of TCE response. My-DST is capable of measuring T cell-dependent killing using the multiple myeloma patient's own bone marrow-derived T cells. SAR442257 shows promise for multiple myeloma and may be best suited for patients declared resistant to both CD38 mAbs and BCMA-targeted therapy.

SIGNIFICANCE

This study introduces the use of My-DST to measure and characterize sensitivity to anti-CD38 T-cell engager SAR442257 in primary samples using matched endogenous T cells. Preclinical testing in samples from patients with diverse treatment history supports further testing in post-chimeric antigen receptor T-cell multiple myeloma.

Isatuximab-carfilzomib-dexamethasone immediately after failing of the quadruplet Daratumumab-bortezomib-lenalidomide-dexamethasone (Dara-VRD): Striking response with no washout in a newly diagnosed multiple myeloma

Biochemical evolution of serum IgG-Kappa monoclonal component during the first line with VRD (x1), DARA-VRD (x4), and the second line with ISA-KD (x4).

CD46-ADC Reduces the Engraftment of Multiple Myeloma Patient-Derived Xenografts

An antibody-drug conjugate (ADC) targeting CD46 conjugated to monomethyl auristatin has a potent anti-myeloma effect in cell lines in vitro and in vivo, and patient samples treated ex vivo. Here, we tested if CD46-ADC may have the potential to target MM-initiating cells (MM-ICs). CD46 expression was measured on primary MM cells with a stem-like phenotype. A patient-derived xenograft (PDX) model was implemented utilizing implanted fetal bone fragments to provide a humanized microenvironment. Engraftment was monitored via serum human light chain ELISA, and at sacrifice via bone marrow and bone fragment flow cytometry. We then tested MM regeneration in PDX by treating mice with CD46-ADC or the nonbinding control-ADC. MM progenitor cells from patients that exhibit high aldehyde dehydrogenase activity also have a high expression of CD46. In PDX, newly diagnosed MM patient samples engrafted significantly more compared to relapsed/refractory samples. In mice transplanted with newly diagnosed samples, CD46-ADC treatment showed significantly decreased engraftment compared to control-ADC treatment. Our data further support the targeting of CD46 in MM. To our knowledge, this is the first study to show preclinical drug efficacy in a PDX model of MM. This is an important area for future study, as patient samples but not cell lines accurately represent intratumoral heterogeneity.