DCE-MRI to distinguish all monoclonal plasma cell disease stages and correlation with diffusion-weighted MRI/PET-based biomarkers in a hybrid simultaneous whole body-2-[18F]FDG-PET/MRI imaging approach.

BACKGROUND: Dynamic contrast-enhanced-MRI (DCE-MRI) is able to study bone marrow angiogenesis in patients with multiple myeloma (MM) and asymptomatic precursor diseases but its role in the management of MM has not yet been established. The aims of this prospective study was to compare DCE-MRI-based parameters between all monoclonal plasma cell disease stages in order to find out discriminatory parameters and to seek correlations with other diffusion-weighted MRI and positron emission tomography (PET)-based biomarkers in a hybrid simultaneous whole-body-2-[18F]fluorodeoxyglucose (FDG)-PET/MRI (WB-2-[18F]FDG-PET/MRI) imaging approach. METHODS: Patients with newly diagnosed Monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM) or symptomatic MM according to international myeloma working group and underwent WB-2-[18F]FDG-PET/MRI imaging including bone marrow DCE sequences at the Nantes University Hospital were prospectively enrolled in this study before receiving treatment. RESULTS: One hundred and sixty-seven patients (N = 167, mean age: 64 years ± 11 [Standard deviation], 66 males) were considered for the analysis. DCE-MRI-based Peak Enhancement Intensity (PEI), Time to PEI (TPEI) and their maximum intensity time ratio (MITR: PEI/TPEI) values were significantly different between the different monoclonal plasma cell disease stages, PEI values increasing and TPEI values decreasing progressively along the spectrum of plasma cell disorders, from MGUS stage to symptomatic multiple myeloma. PEI values were significantly higher in patients with diffuse bone marrow involvement (either in PET or in MRI images) than in those without diffuse bone marrow involvement, unlike TPEI values. PEI and TPEI values were not significantly different between patients with or without focal bone lesions. CONCLUSION: Different DCE-MRI-based parameters (PEI, TPEI, MITR) could significantly differentiate all monoclonal plasma cell disease stages and complemented conventional MRI and PET-based biomarkers.

Bortezomib, thalidomide, and dexamethasone with or without daratumumab and followed by daratumumab maintenance or observation in transplant-eligible newly diagnosed multiple myeloma: long-term follow-up of the CASSIOPEIA randomised controlled phase 3 trial.

BACKGROUND: CASSIOPEIA part 1 demonstrated superior depth of response and prolonged progression-free survival with daratumumab in combination with bortezomib, thalidomide, and dexamethasone (D-VTd) versus bortezomib, thalidomide, and dexamethasone (VTd) alone as an induction and consolidation regimen in transplant-eligible patients newly diagnosed with myeloma. In CASSIOPEIA part 2, daratumumab maintenance significantly improved progression-free survival and increased minimal residual disease (MRD)-negativity rates versus observation. Here, we report long-term study outcomes of CASSIOPEIA. METHODS: CASSIOPEIA was a two-part, open-label, phase 3 trial of patients done at 111 European academic and community-based centres. Eligible patients were aged 18-65 years with transplant-eligible newly diagnosed myeloma and an Eastern Cooperative Oncology Group performance status of 0-2. In part 1, patients were randomly assigned (1:1) to pre-transplant induction and post-transplant consolidation with D-VTd or VTd. Patients who completed consolidation and had a partial response or better were re-randomised (1:1) to intravenous daratumumab maintenance (16 mg/kg every 8 weeks) or observation for 2 years or less. An interactive web-based system was used for both randomisations, and randomisation was balanced using permuted blocks of four. Stratification factors for the first randomisation (induction and consolidation phase) were site affiliation, International Staging System disease stage, and cytogenetic risk status. Stratification factors for the second randomisation (maintenance phase) were induction treatment and depth of response in the induction and consolidation phase. The primary endpoint for the induction and consolidation phase was the proportion of patients who achieved a stringent complete response after consolidation; results for this endpoint remain unchanged from those reported previously. The primary endpoint for the maintenance phase was progression-free survival from second randomisation. Efficacy evaluations in the induction and consolidation phase were done on the intention-to-treat population, which included all patients who underwent first randomisation, and efficacy analyses in the maintenance phase were done in the maintenance-specific intention-to-treat population, which included all patients who were randomly assigned at the second randomisation. This analysis represents the final data cutoff at the end of the study. The trial is registered with ClinicalTrials.gov, NCT02541383. FINDINGS: Between Sept 22, 2015 and Aug 1, 2017, 1085 patients were randomly assigned to D-VTd (n=543) or VTd (n=542); between May 30, 2016 and June 18, 2018, 886 were re-randomised to daratumumab maintenance (n=442) or observation (n=444). At the clinical cutoff date, Sept 1, 2023, median follow-up was 80·1 months (IQR 75·7-85·6) from first randomisation and 70·6 months (66·4-76·1) from second randomisation. Progression-free survival from second randomisation was significantly longer in the daratumumab maintenance group than the observation-alone group (median not reached [95% CI 79·9-not estimable (NE)] vs 45·8 months [41·8-49·6]; HR 0·49 [95% CI 0·40-0·59]; p<0·0001); benefit was observed with D-VTd with daratumumab maintenance versus D-VTd with observation (median not reached [74·6-NE] vs 72·1 months [52·8-NE]; 0·76 [0·58-1·00]; p=0·048) and VTd with daratumumab maintenance versus VTd with observation (median not reached [66·9-NE] vs 32·7 months [27·2-38·7]; 0·34 [0·26-0·44]; p<0·0001). INTERPRETATION: The long-term follow-up results of CASSIOPEIA show that including daratumumab in both the induction and consolidation phase and the maintenance phase led to superior progression-free survival outcomes. Our results confirm D-VTd induction and consolidation as a standard of care, and support the option of subsequent daratumumab monotherapy maintenance, for transplant-eligible patients with newly diagnosed multiple myeloma. FUNDING: Intergroupe Francophone du Myélome, Dutch-Belgian Cooperative Trial Group for Hematology Oncology, and Janssen Research & Development.

Isatuximab, Bortezomib, Lenalidomide, and Dexamethasone for Multiple Myeloma.

BACKGROUND: Bortezomib, lenalidomide, and dexamethasone (VRd) is a preferred first-line treatment option for patients with newly diagnosed multiple myeloma. Whether the addition of the anti-CD38 monoclonal antibody isatuximab to the VRd regimen would reduce the risk of disease progression or death among patients ineligible to undergo transplantation is unclear. METHODS: In an international, open-label, phase 3 trial, we randomly assigned, in a 3:2 ratio, patients 18 to 80 years of age with newly diagnosed multiple myeloma who were ineligible to undergo transplantation to receive either isatuximab plus VRd or VRd alone. The primary efficacy end point was progression-free survival. Key secondary end points included a complete response or better and minimal residual disease (MRD)-negative status in patients with a complete response. RESULTS: A total of 446 patients underwent randomization. At a median follow-up of 59.7 months, the estimated progression-free survival at 60 months was 63.2% in the isatuximab-VRd group, as compared with 45.2% in the VRd group (hazard ratio for disease progression or death, 0.60; 98.5% confidence interval, 0.41 to 0.88; P<0.001). The percentage of patients with a complete response or better was significantly higher in the isatuximab-VRd group than in the VRd group (74.7% vs. 64.1%, P = 0.01), as was the percentage of patients with MRD-negative status and a complete response (55.5% vs. 40.9%, P = 0.003). No new safety signals were observed with the isatuximab-VRd regimen. The incidence of serious adverse events during treatment and the incidence of adverse events leading to discontinuation were similar in the two groups. CONCLUSIONS: Isatuximab-VRd was more effective than VRd as initial therapy in patients 18 to 80 years of age with newly diagnosed multiple myeloma who were ineligible to undergo transplantation. (Funded by Sanofi and a Cancer Center Support Grant; IMROZ ClinicalTrials.gov number, NCT03319667.).

Consensus guidelines and recommendations for the management and response assessment of chimeric antigen receptor T-cell therapy in clinical practice for relapsed and refractory multiple myeloma: a report from the International Myeloma Working Group Immunotherapy Committee.

Chimeric antigen receptor (CAR) T-cell therapy has shown promise in patients with late-line refractory multiple myeloma, with response rates ranging from 73 to 98%. To date, three products have been approved: Idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel), which are approved by the US Food and Drug Administration, the European Medicines Agency, Health Canada (ide-cel only), and Brazil ANVISA (cilta-cel only); and equecabtagene autoleucel (eque-cel), which was approved by the Chinese National Medical Products Administration. CAR T-cell therapy is different from previous anti-myeloma therapeutics with unique toxic effects that require distinct mitigation strategies. Thus, a panel of experts from the International Myeloma Working Group was assembled to provide guidance for clinical use of CAR T-cell therapy in myeloma. This consensus opinion is from experts in the field of haematopoietic cell transplantation, cell therapy, and multiple myeloma therapeutics.

Impact of prior treatment on selinexor, bortezomib, dexamethasone outcomes in patients with relapsed/refractory multiple myeloma: Extended follow-up subgroup analysis of the BOSTON trial.

OBJECTIVES: To analyze the impact of prior therapies on outcomes with selinexor, bortezomib, and dexamethasone (SVd) versus bortezomib and dexamethasone (Vd) in 402 patients with relapsed/refractory multiple myeloma (RRMM) in the phase 3 BOSTON trial. METHODS: Post hoc analysis of progression-free survival (PFS), overall survival (OS), and safety for lenalidomide-refractory, proteasome inhibitor (PI)-naïve, bortezomib-naïve, and one prior line of therapy (1LOT) patient subgroups. RESULTS: At a median follow-up of over 28 months, clinically meaningful improvements in PFS were noted across all groups with SVd. The median SVd PFS was longer in all subgroups (lenalidomide-refractory: 10.2 vs. 7.1 months, PI-naïve: 29.5 vs. 9.7; bortezomib-naïve: 29.5 vs. 9.7; 1LOT: 21.0 vs. 10.7; p < .05). The lenalidomide-refractory subgroup had longer OS with SVd (26.7 vs. 18.6 months; HR 0.53; p = .015). In all subgroups, overall response and ≥very good partial response rates were higher with SVd. The manageable safety profile of SVd was similar to the overall patient population. CONCLUSIONS: With over 2 years of follow-up, these clinically meaningful outcomes further support the use of SVd in patients who are lenalidomide-refractory, PI-naïve, bortezomib-naïve, or who received 1LOT (including a monoclonal antibody) and underscore the observed synergy between selinexor and bortezomib.

Twice-weekly induction with ixazomib-lenalidomide-dexamethasone (IRd) combination followed by extended IRd consolidation and lenalidomide maintenance in transplant-eligible patients with newly diagnosed multiple myeloma: Results of the phase 2 study IFM2014-03.

Therapeutic strategies for patients with newly diagnosed multiple myeloma (NDMM) have considerably improved during the last 10 years. The IFM2014-03 trial proposed an all-oral triplet induction/consolidation regimen in transplant-eligible NDMM patients, followed by lenalidomide maintenance. Induction consisted of three 21-day cycles of ixazomib, lenalidomide and dexamethasone (IRd), before high-dose Melphalan with transplant followed by eight 28-day cycles of IRd consolidation before 13 cycles of lenalidomide maintenance. Forty-six patients were enrolled and received at least one dose of therapy, and 39 entered the maintenance phase. The primary end-point was stringent complete response after consolidation, and was achieved in nine patients (20.9%, 90% CI 11.4-33.7; p = 0.998). Ten patients (24.4%) had an undetectable minimal residual disease. The overall response rate was 95.7%. The 3-year progression-free survival was 66.3%. No unexpected toxicities were recorded, and only eight patients suspended from any study drug. Of note, 21 (45.7%) patients reported peripheral neuropathy (PN) (grades 1-2 with no serious adverse events). IRd induction and consolidation with transplant before lenalidomide maintenance shows lower response rates compared to other triplet therapies. It could be an alternative for patients who require an all-oral regimen and/or with pre-existent PN, especially if quadruplet regimens including anti-CD38 antibody are not available.

An IL-1ß-driven neutrophil-stromal cell axis fosters a BAFF-rich protumor microenvironment in individuals with multiple myeloma.

Human bone marrow permanently harbors high numbers of neutrophils, and a tumor-supportive bias of these cells could significantly impact bone marrow-confined malignancies. In individuals with multiple myeloma, the bone marrow is characterized by inflammatory stromal cells with the potential to influence neutrophils. We investigated myeloma-associated alterations in human marrow neutrophils and the impact of stromal inflammation on neutrophil function. Mature neutrophils in myeloma marrow are activated and tumor supportive and transcribe increased levels of IL1B and myeloma cell survival factor TNFSF13B (BAFF). Interactions with inflammatory stromal cells induce neutrophil activation, including BAFF secretion, in a STAT3-dependent manner, and once activated, neutrophils gain the ability to reciprocally induce stromal activation. After first-line myeloid-depleting antimyeloma treatment, human bone marrow retains residual stromal inflammation, and newly formed neutrophils are reactivated. Combined, we identify a neutrophil-stromal cell feed-forward loop driving tumor-supportive inflammation that persists after treatment and warrants novel strategies to target both stromal and immune microenvironments in multiple myeloma.

Plain language summary of the KarMMa-3 study of ide-cel or standard of care regimens in people with relapsed or refractory multiple myeloma.

What is this summary about? This plain language summary describes the results of a Phase 3 study called KarMMa-3. In this ongoing study, researchers looked at a relatively new treatment for people with multiple myeloma, a type of blood cancer, whose cancer got worse despite treatment (refractory) or had cancer that at first improved with treatment, but eventually stopped responding (relapsed).How was this study conducted? In the KarMMa-3 study, people with relapsed or refractory multiple myeloma received either a one-time infusion of a new treatment, named ide-cel, or one of the standard of care regimens currently available for patients with this cancer. People were treated with the standard of care regimens in weekly or monthly cycles until the cancer got worse, there were unacceptable side effects, or the person withdrew from the study.What were the results? The results of this study showed that people receiving the one-time infusion of ide-cel lived longer without the cancer getting worse and had a greater reduction in cancer cells than patients receiving the standard of care regimen. A higher percentage of patients receiving ide-cel responded to treatment than patients receiving the standard of care regimen, and the response to treatment was better with idecel. These results show that ide-cel is a promising treatment for this challenging disease.Clinical Trial Registration: NCT03651128 (KarMMa-3 study).

Correlation of immune fitness with response to teclistamab in relapsed/refractory multiple myeloma in MajesTEC-1.

Teclistamab, an off-the-shelf B-cell maturation antigen (BCMA) × CD3 bispecific antibody that mediates T-cell activation and subsequent lysis of BCMA-expressing myeloma cells, is approved for the treatment of patients with relapsed/refractory multiple myeloma (RRMM). As a T-cell redirection therapy, clinical outcomes with teclistamab may be influenced by patient immune fitness and tumor antigen expression. We correlated tumor characteristics and baseline immune profiles with clinical response and disease burden in patients with RRMM from the pivotal phase 1/2 MajesTEC-1 study, focusing on patients treated with 1.5 mg/kg of teclistamab (N = 165). Peripheral blood samples were collected at screening and bone marrow samples were collected at screening and cycle 3. Better clinical outcomes to teclistamab correlated with higher baseline total T-cell counts in the periphery. In addition, responders (partial response or better) had a lower proportion of immunosuppressive regulatory T cells, T cells expressing co-inhibitory receptors (CD38, PD-1, PD-1/TIM-3), and soluble BCMA, and a T-cell profile suggestive of a more cytolytic potential, compared with nonresponders. Neither frequency of baseline bone marrow BCMA expression nor BCMA receptor density were associated with clinical response to teclistamab. Improved progression-free survival was observed in patients with a lower frequency of T cells expressing exhaustion markers and immunosuppressive regulatory T cells. Overall, response to teclistamab was associated with baseline immune fitness; nonresponders had immune profiles suggestive of immune suppression and T-cell dysfunction. These findings illustrate the importance of the contribution of the immune landscape to T-cell redirection therapy response. This trial was registered at www.ClinicalTrials.gov, NCT03145181/NCT04557098.

Mechanisms of resistance to bispecific T-cell engagers in multiple myeloma and their clinical implications.

ABSTRACT: Bispecific T-cell engagers (TCEs) are revolutionizing patient care in multiple myeloma (MM). These monoclonal antibodies, that redirect T cells against cancer cells, are now approved for the treatment of triple-class exposed relapsed/refractory MM (RRMM). They are currently tested in earlier lines of the disease, including in first line. Yet, primary resistance occurs in about one-third of patients with RRMM, and most responders eventually develop acquired resistance. Understanding the mechanisms of resistance to bispecific TCE is thus essential to improve immunotherapies in MM. Here, we review recent studies investigating the clinical and molecular determinants of resistance to bispecific TCE. Resistance can arise from tumor-intrinsic or tumor-extrinsic mechanisms. Tumor-intrinsic resistance involves various alterations leading to the loss of the target antigen, such as chromosome deletions, point mutations, or epigenetic silencing. Loss of major histocompatibility complex (MHC) class I, preventing MHC class I: T-cell receptor (TCR) costimulatory signaling, was also reported. Tumor-extrinsic resistance involves abundant exhausted T-cell clones and several factors generating an immunosuppressive microenvironment. Importantly, some resistance mechanisms impair response to 1 TCE while preserving the efficacy of others. We next discuss the clinical implications of these findings. Monitoring the status of target antigens in tumor cells and their immune environment will be key to select the most appropriate TCE for each patient and to design combination and sequencing strategies for immunotherapy in MM.

An open-label phase 2 study treating patients with first or second relapse of multiple myeloma with carfilzomib, pomalidomide, and dexamethasone (KPd): SELECT study.

Once-weekly carfilzomib at 56 mg/m2 plus immunomodulatory drugs and dexamethasone has shown efficacy and tolerability treating early relapsed/refractory multiple myeloma (RRMM). The phase 2 SELECT study (NCT04191616) evaluated efficacy/safety of weekly carfilzomib, pomalidomide, and dexamethasone (KPd) in early RRMM patients refractory to lenalidomide. All 52 treated patients were refractory to prior treatment, and 19 (37%) were triple-class refractory. Overall response rate (ORR; primary endpoint) was 58% (35% ≥ very good partial response, 6% ≥ complete response); median response duration was 20.3 months. Minimal residual disease negativity (10-5) was achieved in 10% of patients. Median progression-free survival was 11.1 months; median overall survival was 18.8 months. Adverse events (AEs) were consistent with the known safety profile including grade ≥3 treatment-emergent AEs reported in 67% of patients. Although the primary endpoint of ORR was not met, KPd showed meaningful clinical benefits in lenalidomide-refractory RRMM patients, including those who were daratumumab-refractory and/or triple-class refractory.

Adjusting for subsequent therapies in the TOURMALINE-MM1 study shows clinically meaningful improvement in overall survival with addition of ixazomib to lenalidomide and dexamethasone.

TOURMALINE-MM1, the only blinded randomized study in patients with relapsed and/or refractory multiple myeloma (RRMM; ≥1 prior therapy) in the last 10 years, investigated ixazomib+lenalidomide+dexamethasone (IRd) versus lenalidomide+dexamethasone (Rd). Final overall survival (OS) data were based on a median follow-up of 85 months. In RRMM trials where patients have had 1-3 relapses after initial treatment, a high proportion receive subsequent therapy. Application of salvage therapies in blinded trials and newer modes of therapy can increasingly complicate the interpretation of OS. This analysis explores the impact of subsequent therapies on OS outcomes in TOURMALINE-MM1. The inverse probability of censoring weights (IPCW) method, marginal structural model (MSM), and rank preserving structural failure time model (RPSFTM) were utilized to adjust for confounding on OS, introduced by subsequent therapies. Analyses were conducted for the intentto-treat (ITT) population and ≥2 prior lines subgroup. Unadjusted hazard ratio (HR) for IRd versus Rd was 0.94 (95% confidence interval [CI]: 0.78-1.13) in the ITT population. After adjusting for the impact of subsequent therapies by the RPSFTM method, estimated HR for IRd versus Rd in the ITT population was 0.89 (95% CI: 0.74-1.07). Adjusting with IPCW and MSM methods also showed an improvement in HR, favoring IRd. IRd may be particularly beneficial in patients with ≥2 prior lines of therapy (IPCW and MSM HR=0.52, 95% CI: 0.30-0.88; RPSFTM HR=0.68, 95% CI: 0.51-0.91). These analyses highlight the growing challenge of demonstrating OS benefit in multiple myeloma patients and the importance of assessing confounding introduced by subsequent therapies when interpreting OS.

Isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone in patients with relapsed and refractory multiple myeloma: final overall survival analysis.

The primary and prespecified updated analyses of ICARIA-MM (clinicaltrial gov. Identifier: NCT02990338) demonstrated improved progression-free survival (PFS) and a benefit in overall survival (OS) was reported with the addition of isatuximab, an anti-CD38 monoclonal antibody, to pomalidomide-dexamethasone (Pd) in patients with relapsed/refractory multiple myeloma. Here, we report the final OS analysis. This multicenter, randomized, open-label, phase III study included patients who had received and failed ≥2 previous therapies, including lenalidomide and a proteasome inhibitor. Between January 10, 2017, and February 2, 2018, 307 patients were randomized (1:1) to isatuximab-pomalidomide-dexamethasone (Isa-Pd; N=154) or Pd (N=153), stratified based on age (<75 vs. ≥75 years) and number of previous lines of therapy (2-3 vs. >3). At data cutoff for the final OS analysis after 220 OS events (January 27, 2022), median follow-up duration was 52.4 months. Median OS was 24.6 months (95% confidence interval [CI]: 20.3-31.3) with Isa-Pd and 17.7 months (95% CI: 14.4- 26.2) with Pd (hazard ratio=0.78; 95% CI: 0.59-1.02; 1-sided P=0.0319). Despite subsequent daratumumab use in the Pd group and its potential benefit on PFS in the first subsequent therapy line, median PFS2 was significantly longer with Isa-Pd versus Pd (17.5 vs. 12.9 months; log-rank 1-sided P=0.0091). In this analysis, Isa-Pd continued to be efficacious and well tolerated after follow-up of approximately 52 months, contributing to a clinically meaningful, 6.9-month improvement in median OS in patients with relapsed/refractory multiple myeloma.

Daratumumab, carfilzomib, lenalidomide, and dexamethasone with tandem transplant for high-risk newly diagnosed myeloma.

ABSTRACT: High-risk (HR) cytogenetics are associated with poor outcomes in newly diagnosed multiple myeloma (NDMM), and dedicated studies should address this difficult-to-treat population. The phase 2 study 2018-04 from the Intergroupe Francophone du Myelome evaluated feasibility of an intensive strategy with quadruplet induction and consolidation plus tandem transplant in HR transplant-eligible (TE) NDMM. HR cytogenetics were defined by presence of del(17p), t(4;14), and/or t(14;16). Treatment consisted of daratumumab-carfilzomib-lenalidomide-dexamethasone (D-KRd) induction, autologous stem cell transplantation (ASCT), D-KRd consolidation, second ASCT, and daratumumab-lenalidomide maintenance. The primary end point was feasibility. Fifty patients with previously untreated NDMM were included. Median age was 57. Del(17p), t(4;14), and t(14;16) were found in 40%, 52%, and 20% of patients, respectively. At data cutoff, the study met the primary end point with 36 patients completing second transplant. Twenty patients discontinued the study due to stem cell collection failure (n = 8), disease progression (n = 7), adverse event (n = 4), or consent withdrawal (n = 1). Grade 3 to 4 D-KRd induction/consolidation-related adverse events (>5% of patients) were neutropenia (39%), anemia (12%), thrombocytopenia (7%), and infection (6%). The overall response rate was 100% for patients completing second transplant, including 81% complete response. Premaintenance minimal residual disease (MRD) negativity rate (10-6) was 94%. After a median follow-up of 33 months, the 30-month progression-free survival (PFS) and overall survival were 80% and 91%, respectively. In conclusion, D-KRd with tandem transplant is feasible in patients with HR TE-NDMM and resulted in high response rates and PFS. This trial was registered at www.clinicaltrials.gov as #NCT03606577.

Comparative Efficacy of Talquetamab vs. Current Treatments in the LocoMMotion and MoMMent Studies in Patients with Triple-Class-Exposed Relapsed/Refractory Multiple Myeloma.

INTRODUCTION: Talquetamab, a bispecific antibody targeting GPRC5D × CD3, is approved for the treatment of patients with triple-class -exposed (TCE) relapsed/refractory multiple myeloma (RRMM) on the basis of the results from the phase I/II MonumenTAL-1 trial. The relative effectiveness of talquetamab vs. real-world physician's choice of therapy (RWPC) was assessed using adjusted comparisons. METHODS: An external control arm for MonumenTAL-1 (subcutaneously administered talquetamab 0.4 mg/kg weekly [QW] and 0.8 mg/kg every other week [Q2W]) was created from two observational real-world studies: LocoMMotion and MoMMent. Imbalances in baseline covariates were adjusted using inverse probability weighting. The relative effectiveness of talquetamab vs. RWPC was estimated for overall response rate (ORR), ≥ very good partial response (VGPR), and ≥ complete response (CR); odds ratios and relative response ratios (RRs) were derived from weighted logistic regression. Hazard ratios (HRs) for duration of response (DOR), progression-free survival (PFS), time to next treatment (TTNT), and overall survival (OS) were estimated using a weighted Cox proportional hazards model. RESULTS: After reweighting, baseline characteristics were balanced across cohorts. In adjusted comparisons, patients treated with talquetamab QW (n = 143) had significantly improved outcomes vs. RWPC; RRs were ORR 2.67, p < 0.0001; ≥ VGPR 4.70, p < 0.0001; ≥ CR 78.05, p = 0.0002; and HRs were PFS 0.52, p < 0.0001; TTNT 0.48, p < 0.0001; OS 0.36, p < 0.0001. Patients treated with talquetamab Q2W (n = 145) also had significantly improved outcomes vs. RWPC; RRs were ORR 2.62, p < 0.0001; ≥ VGPR 5.04, p < 0.0001; ≥ CR 101.14, p = 0.0002; and HRs were PFS 0.40, p < 0.0001; TTNT 0.39, p < 0.0001; OS 0.37, p < 0.0001. CONCLUSION: Effectiveness of talquetamab for both schedules was significantly better than RWPC for ORR, ≥ VGPR, ≥ CR, PFS, OS, and TTNT, highlighting its clinical benefit for patients with TCE RRMM. TRIAL REGISTRATION: MonumenTAL-1, ClinicalTrials.gov identifier NCT03399799/NCT04634552; LocoMMotion, ClinicalTrials.gov identifier NCT04035226; MoMMent, ClinicalTrials.gov identifier NCT05160584.

GPRC5D as a novel target for the treatment of multiple myeloma: a narrative review.

Multiple myeloma is a genetically complex and heterogenous malignancy with a 5-year survival rate of approximately 60%. Despite advances in therapy, patients experience cycles of remission and relapse, with each successive line of therapy associated with poorer outcomes; therefore, therapies with different mechanisms of action against new myeloma antigens are needed. G protein-coupled receptor class C group 5 member D (GPRC5D) has emerged as a novel therapeutic target for the treatment of multiple myeloma. We review the biology and target validation of GPRC5D, and clinical data from early phase trials of GPRC5D-targeting bispecific antibodies, talquetamab and forimtamig, and chimeric antigen receptor T cell (CAR-T) therapies, MCARH109, OriCAR-017, and BMS-986393. In addition to adverse events (AEs) associated with T-cell-redirection therapies irrespective of target, a consistent pattern of dermatologic and oral AEs has been reported across several trials of GPRC5D-targeting bispecific antibodies, as well as rare cerebellar events with CAR-T therapy. Additional studies are needed to understand the underlying mechanisms involved in the development of skin- and oral-related toxicities. We review the strategies that have been used to manage these GPRC5D-related toxicities. Preliminary efficacy data showed overall response rates for GPRC5D-targeting T-cell-redirecting therapies were ≥64%; most responders achieved a very good partial response or better. Pharmacokinetics/pharmacodynamics showed that these therapies led to cytokine release and T-cell activation. In conclusion, results from early phase trials of GPRC5D-targeting T-cell-redirecting agents have shown promising efficacy and manageable safety profiles, including lower infection rates compared with B-cell maturation antigen- and Fc receptor-like protein 5-targeting bispecific antibodies. Further clinical trials, including those investigating GPRC5D-targeting T-cell-redirecting agents in combination with other anti-myeloma therapies and with different treatment modalities, may help to elucidate the future optimal treatment regimen and sequence for patients with multiple myeloma and improve survival outcomes. Video Summary.

Isatuximab in combination with carfilzomib and dexamethasone in 1q21+ patients with relapsed/refractory multiple myeloma: Long-term outcomes in the Phase 3 IKEMA study.

Gain/amplification of 1q21 (≥3 copies), a chromosomal abnormality frequently observed in multiple myeloma, can negatively affect prognosis, due to its involvement in resistance to anti-myeloma therapy and disease progression. In this updated subgroup analysis of the randomized, Phase 3 IKEMA study (NCT03275285) in relapsed/refractory multiple myeloma (RRMM), we evaluated progression-free survival (PFS) and depth of response with the anti-CD38 antibody isatuximab plus carfilzomib-dexamethasone (Isa-Kd) versus Kd, in 1q21+ patients and related subgroups, at long-term follow-up (44.2 months). Our analysis included patients with 1q21+ (≥3 copies, with/without high-risk chromosomal abnormality [HRCA]), isolated 1q21+ (≥3 copies, without HRCA), gain(1q21) (3 copies, with/without HRCA), and amp(1q21) (≥4 copies, with/without HRCA). PFS benefit was achieved with Isa-Kd versus Kd in patients with 1q21+ (HR 0.58, 95% CI: 0.37-0.92), with isolated 1q21+ (HR 0.49, 95% CI: 0.27-0.92), with gain(1q21), or amp(1q21), consistent with the overall population and prior interim 1q21+ subgroup analyses. Median PFS with Isa-Kd versus Kd was 25.8 versus 16.2 months in 1q21+ patients and 38.2 versus 16.2 months in patients with isolated 1q21+. Clinically meaningful, higher rates of very good partial response or better, complete response or better (≥CR), minimal residual disease (MRD) negativity, and MRD negativity and ≥CR were reached with Isa-Kd versus Kd in patients with 1q21+, isolated 1q21+, gain(1q21), or amp(1q21). In Isa-Kd and Kd, the MRD negativity and ≥CR rate was 29.3% versus 15.4% in 1q21+ patients, 36.2% versus 12.9% in patients with isolated 1q21+, 27.9% versus 13.5% in patients with gain(1q21), and 31.3% versus 20.0% in patients with amp(1q21), respectively. In conclusion, addition of Isa to Kd in triplet combination therapy has shown PFS benefit and deeper responses, compared with Kd, in 1q21+ patients at higher risk of progression, including patients with isolated 1q21+, gain(1q21), and amp(1q21), thus supporting Isa-Kd an effective treatment option for patients with RRMM.

Characterization and Outcomes of Spanish Patients With Relapsed/Refractory Multiple Myeloma Included in the LocoMMotion Study.

BACKGROUND: Despite advances in treatments for multiple myeloma (MM), most patients relapse and become refractory to standard drug classes including immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and anti-CD38 antibodies. The LocoMMotion study showed poor clinical outcomes in triple-class exposed patients with relapsed/refractory MM (RRMM) treated with real-world clinical practice (RWCP) therapy. Here, we report efficacy outcomes for Spanish patients receiving RWCP treatments in the LocoMMotion study compared with the full cohort. PATIENTS AND METHODS: The prospective, noninterventional, multinational LocoMMotion study (NCT04035226) enrolled 248 patients who had received ≥ 3 prior lines of therapy (LOT), including a PI, an IMiD, and an anti-CD38 antibody, with disease progression during or after their last LOT. The primary endpoint was overall response rate (ORR). Secondary endpoints included progression-free survival (PFS) and overall survival (OS). RESULTS: Spanish patients (n = 24) had received a median of 4 prior LOT (range, 2-7). At 29.2 months median follow-up, patients had received 14 different treatment regimens used in RWCP during the study. Efficacy outcomes were consistent between the Spanish cohort and overall study population. The ORR was 29.2% (95% CI, 12.6%-51.1%). Median PFS and OS were 4.6 months (95% CI, 1.2-6.3) and 11.6 months (95% CI, 6.4-24.5), respectively. CONCLUSION: Spanish patients from the LocoMMotion study demonstrated poor outcomes in response to RWCP treatments consistent with those of the overall study population, highlighting the need for access to new and effective therapies for patients with RRMM in Spain and globally.