Cost-per-responder analysis of patients with lenalidomide-refractory multiple myeloma receiving ciltacabtagene autoleucel in CARTITUDE-4.

Introduction: Ciltacabtagene autoleucel (cilta-cel) is a chimeric antigen receptor T-cell therapy approved for patients with relapsed/refractory multiple myeloma (RRMM). In the phase 3 trial, CARTITUDE-4 (NCT04181827), cilta-cel demonstrated improved efficacy vs. standard of care (SOC; daratumumab plus pomalidomide and dexamethasone [DPd] or pomalidomide plus bortezomib and dexamethasone [PVd]) with a ≥ complete response (≥CR) rate of 73.1% vs. 21.8%. Methods: A cost-per-responder model was developed to assess the value of cilta-cel and SOC (87% DPd and 13% PVd) based on the CARTITUDE-4 trial data from a US mixed payer perspective (76.7% commercial, 23.3% Medicare). The model was developed using progression-free survival (PFS), overall survival (OS), and ≥CR endpoints from CARTITUDE-4 over a period of 25.4 months. Inpatient stays, outpatient visits, drug acquisition, administration, and monitoring costs were included. The base-case model assumed an inpatient setting for each cilta-cel infusion; another scenario included 30% outpatient and 70% inpatient infusions. Costs of managing grade 3-4 adverse events (AEs) and grade 1-4 cytokine release syndrome and neurotoxicity were included. Subsequent therapy costs were incurred after disease progression; terminal care costs were considered upon death events. Outcomes included total cost per treated patient, total cost per complete responder, and cost per month in PFS between cilta-cel and SOC. Costs were adjusted to 2024 US dollars. Results: Total cost per treated patient, total cost per complete responder, and total cost per month in PFS were estimated at $704,641, $963,941, and $30,978 for cilta-cel, respectively, and $840,730, $3,856,559, and $42,520 for SOC over the 25.4-month period. Cost drivers included treatment acquisition costs before progression and subsequent treatment costs ($451,318 and $111,637 for cilta-cel; $529,795 and $265,167 for SOC). A scenario analysis in which 30% of patients received an outpatient infusion (assuming the same payer mix) showed a lower cost per complete responder for cilta-cel ($956,523) than those with an infusion in the inpatient setting exclusively. Discussion: This analysis estimated that cost per treated patient, cost per complete responder, and cost per month in PFS for cilta-cel were remarkably lower than for DPd or PVd, highlighting the substantial clinical and economic benefit of cilta-cel for patients with RRMM.

Multiple Myeloma Risk and Outcomes are Associated with Pathogenic Germline Variants in DNA Repair Genes.

First-degree relatives of multiple myeloma (MM) patients are at increased risk for MM, but the contribution of pathogenic germline variants (PGVs) in hereditary cancer genes to MM risk and outcomes is not well characterized. To address this, we analyzed germline exomes in two independent cohorts of 895 and 786 MM patients. PGVs were identified in 8.6% of the discovery cohort and 11.5% of the replication cohort, with a notable presence of high or moderate-penetrance PGVs (PGV-As) in DNA repair genes (3.6% and 4.1%, respectively). PGVs in BRCA1 (OR=3.9, FDR<0.01) and BRCA2 (OR=7.0, FDR<0.001) were significantly enriched in MM patients compared to 134,187 healthy controls. Five of the eight BRCA2 PGV carriers exhibited tumor-specific copy number loss in BRCA2, suggesting somatic loss of heterozygosity. PGV-As were associated with younger age at diagnosis, personal or familial cancer history, and longer progression-free survival after upfront high-dose melphalan and autologous stem cell transplant (p<0.01).

Ide-cel vs standard regimens in triple-class-exposed relapsed and refractory multiple myeloma: updated KarMMa-3 analyses.

Outcomes are poor in triple-class-exposed (TCE) relapsed/refractory multiple myeloma (RRMM). In the phase 3 KarMMa-3 (clinicaltrials.gov; NCT03651128) trial, patients with TCE RRMM and 2-4 prior regimens were randomized 2:1 to idecabtagene vicleucel (ide-cel) or standard regimens (SRs). An interim analysis (IA) demonstrated significantly longer median progression-free survival (PFS; primary endpoint; 13.3 vs 4.4 months; P<.0001) and higher overall response rate (ORR) with ide-cel vs SRs. At final PFS analysis (median follow-up, 30.9 months), ide-cel further improved median PFS vs SRs (13.8 vs 4.4 months; hazard ratio (HR), 0.49; 95% confidence interval (CI), 0.38-0.63). PFS benefit with ide-cel vs SRs was observed regardless of number of prior lines of therapy, with greatest benefit after 2 prior lines (16.2 vs 4.8 months, respectively). ORR benefit was maintained with ide-cel vs SRs (71% vs 42%; complete response, 44% vs 5%). Patient-centric design allowed crossover from SRs (56%) to ide-cel upon progressive disease, confounding overall survival (OS) interpretation. At IA of OS, median (95% CI) was 41.4 (30.9-not reached [NR]) vs 37.9 (23.4-NR) months with ide-cel and SRs, respectively (HR, 1.01; 95% CI 0.73-1.40); median OS in both arms was longer than historical data (9-22 months). Two prespecified analyses adjusting for crossover showed OS favoring ide-cel. This trial highlighted the importance of individualized bridging therapy to ensure adequate disease control during ide-cel manufacturing. Ide-cel improved patient-reported outcomes vs SRs. No new safety signals were reported. These results demonstrate the continued favorable benefit-risk profile of ide-cel in early-line and TCE RRMM. NCT03651128.

Comprehensive molecular profiling of multiple myeloma identifies refined copy number and expression subtypes.

Multiple myeloma is a treatable, but currently incurable, hematological malignancy of plasma cells characterized by diverse and complex tumor genetics for which precision medicine approaches to treatment are lacking. The Multiple Myeloma Research Foundation's Relating Clinical Outcomes in Multiple Myeloma to Personal Assessment of Genetic Profile study ( NCT01454297 ) is a longitudinal, observational clinical study of newly diagnosed patients with multiple myeloma (n = 1,143) where tumor samples are characterized using whole-genome sequencing, whole-exome sequencing and RNA sequencing at diagnosis and progression, and clinical data are collected every 3 months. Analyses of the baseline cohort identified genes that are the target of recurrent gain-of-function and loss-of-function events. Consensus clustering identified 8 and 12 unique copy number and expression subtypes of myeloma, respectively, identifying high-risk genetic subtypes and elucidating many of the molecular underpinnings of these unique biological groups. Analysis of serial samples showed that 25.5% of patients transition to a high-risk expression subtype at progression. We observed robust expression of immunotherapy targets in this subtype, suggesting a potential therapeutic option.

The Effect of Age and Other Patient Characteristics on Outcomes Among Nontransplanted Patients Who Were Treated With First-Line Lenalidomide, Bortezomib, and Dexamethasone: Results From the ConnectⓇ MM Registry.

BACKGROUND: Lenalidomide (R), bortezomib (V), and dexamethasone (d) is a standard-of-care regimen in newly diagnosed multiple myeloma (NDMM); however, characteristics and outcomes for nontransplanted patients receiving frontline RVd are not well understood. PATIENTS: The ConnectⓇ MM Registry is a large, US, multicenter, prospective observational cohort study of NDMM patients. METHODS: This analysis investigated characteristics and outcomes of patients who received RVd alone or followed by Rd or R (RVd ± Rd/R) who did not undergo frontline autologous stem cell transplantation. RESULTS: As of August 2021, 314 of 1979 nontransplanted patients received RVd ± Rd/R as initial therapy. Of these, 135 were aged ≤ 65 years and 179 were > 65 years. 108 patients had time to relapse (TTR) of ≤ 12 months and 182 had TTR > 12 months. Baseline characteristics were comparable regardless of TTR and age group except renal function, which was more commonly impaired in older patients. Among patients aged ≤ 65 and > 65 years, median duration of first-line treatment was 6.3 and 9.0 months, median time to next line for those who received second-line therapy was 15.5 and 15.2 months, median progression-free survival (PFS) was 19.3 and 23.0 months, and median overall survival was 60.0 and 59.1 months, respectively. High-risk disease (per IMWG criteria) and high serum calcium were associated with higher hazard of progression or death; the adjusted PFS hazard ratio with respect to age (≤ 65 vs. > 65 years) based on multivariable analysis was 1.18 (0.89-1.57; P = .25). CONCLUSION: These results indicate RVd is active across age groups and provide a better understanding of outcomes with RVd in NDMM.

Linvoseltamab for Treatment of Relapsed/Refractory Multiple Myeloma.

PURPOSE: We present a phase I/II first-in-human trial evaluating the safety and efficacy of 50 mg and 200 mg doses of linvoseltamab, a B-cell maturation antigen × CD3 bispecific antibody in relapsed/refractory multiple myeloma (RRMM). METHODS: Phase II eligible patients had RRMM that either progressed on/after ≥three lines of therapy including a proteasome inhibitor (PI), an immunomodulatory drug (IMiD), and an anti-CD38 antibody or was triple-class (PI/IMiD/anti-CD38) refractory. Phase II treatment was once a week through week 14 and then once every 2 weeks. Phase II 200 mg patients who achieved a ≥very good partial response by week 24 received linvoseltamab once every 4 weeks. The primary end point in phase II was overall response rate (ORR). RESULTS: Among the 117 patients treated with 200 mg, the median age was 70 years, 39% had high-risk cytogenetics, and 28% had penta-refractory disease. At a median follow-up of 14.3 months, the ORR was 71%, with 50% achieving ≥complete response (CR). In 104 patients treated with 50 mg at a median follow-up of 7.4 months, the ORR was 48%, with 21% achieving ≥CR. The median duration of response (DOR) for 200 mg patients (n = 83) was 29.4 months (95% CI, 19.2 to not evaluable). Among 200 mg patients, the most common adverse events included cytokine release syndrome (35.0% Gr1, 10.3% Gr2, 0.9% Gr3), neutropenia (0.9% Gr2, 18.8% Gr3, 23.1% Gr4), and anemia (3.4% Gr1, 4.3% Gr2, 30.8% Gr3). Immune effector cell-associated neurotoxicity syndrome occurred in 7.7% of patients (2.6% each Gr1, Gr2, Gr3). Infections were reported in 74.4% of patients (33.3% Gr3, 2.6% Gr4); infection frequency and severity declined over time. CONCLUSION: Linvoseltamab 200 mg induced deep and durable responses, with a median DOR of 29.4 months, in patients with RRMM with an acceptable safety profile.

Absolute lymphocyte count after BCMA CAR-T therapy is a predictor of response and outcomes in relapsed multiple myeloma.

ABSTRACT: B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor T cells (CAR-Ts) used in multiple myeloma (MM) are rapidly becoming a mainstay in the treatment of relapsed/refractory (R/R) disease, and CAR-T expansion after infusion has been shown to inform depth and duration of response (DoR), but measuring this process remains investigational. This multicenter study describes the kinetics and prognostic impact of absolute lymphocyte count (ALC) in the first 15 days after CAR-T infusion in 156 patients with relapsed MM treated with the BCMA-targeting agents ciltacabtagene autoleucel and idecabtagene vicleucel. Patients with higher maximum ALC (ALCmax) had better depth of response, progression-free survival (PFS), and DoR. Patients with ALCmax >1.0 × 103/µL had a superior PFS (30.5 months vs 6 months; P < .001) compared with those with ≤1.0 × 103/µL, whereas patients with ALCmax ≤0.5 × 103/µL represent a high-risk group with early disease progression and short PFS (hazard ratio, 3.4; 95% confidence interval, 2-5.8; P < .001). In multivariate analysis, ALCmax >1.0 × 103/µL and nonparaskeletal extramedullary disease were the only independent predictors of PFS and DoR after accounting for international staging systemic staging, age, CAR-T product, high-risk cytogenetics, and the number of previous lines. Moreover, our flow cytometry data suggest that ALC is a surrogate for BCMA CAR-T expansion and can be used as an accessible prognostic marker. We report, to our knowledge, for the first time the association of ALC after BCMA CAR-T infusion with clinical outcomes and its utility in predicting response in patients with R/R MM.

Cilta-cel, a BCMA-targeting CAR-T therapy for patients with multiple myeloma.

INTRODUCTION: Ciltacabtagene autoleucel (cilta-cel), a BCMA-targeting CAR-T therapy, is approved in the United States and Europe for patients with relapsed/refractory multiple myeloma (RRMM) and ≥1 prior line of therapy (LOT), including a proteasome inhibitor and an immunomodulatory drug, and are lenalidomide refractory. AREAS COVERED: We examine recent long-term data in heavily pretreated RRMM (LEGEND-2, CARTITUDE-1) and earlier LOTs (CARTITUDE-4) compared with standard therapy and discuss the rationale for investigating cilta-cel as frontline therapy for transplant-eligible and transplant-ineligible patients (CARTITUDE-5, CARTITUDE-6). EXPERT OPINION: CAR-T therapies can improve outcomes for patients with MM across different LOTs. CARTITUDE-1 and CARTITUDE-4 have set a new bar for efficacy, with median PFS of 34.9 months in heavily pretreated patients (CARTITUDE-1) and a 74% relative risk reduction for progression/death versus standard care in patients with 1-3 prior LOTs (CARTITUDE-4), with manageable safety. Response rates were consistent between the two studies: 98% in CARTITUDE-1 and approaching 100% for infused patients in CARTITUDE-4. Cilta-cel could be a key treatment choice for patients with RRMM after first LOT. Clinical trials investigating frontline cilta-cel therapy will provide valuable insights into optimizing treatment pathways with the aim to potentially cure MM.

Phase 1 study combining elotuzumab with autologous stem cell transplant and lenalidomide for multiple myeloma.

BACKGROUND: Autologous stem cell transplantation (ASCT) after induction therapy improves disease-free survival for patients with multiple myeloma (MM). While the goal of ASCT is to render a minimal disease state, it is also associated with eradication of immunosuppressive cells, and we hypothesize that early introduction of immunotherapy post-ASCT may provide a window of opportunity to boost treatment efficacy. METHODS: We conducted a phase 1 clinical trial to investigate the application of autologous lymphocyte infusion and anti-SLAMF7 monoclonal antibody, elotuzumab, after ASCT in patients with newly diagnosed MM previously treated with induction therapy. In addition to CD34+ stem cells, peripheral blood mononuclear cells were harvested prior to transplant and infused on day 3 after stem cell infusion to accelerate immune reconstitution and provide autologous natural killer (NK) cells that are essential to the mechanism of elotuzumab. Elotuzumab was administered starting on day 4 and then every 28 days after until 1 year post-ASCT. Cycles 4-12 were administered with standard-of-care lenalidomide maintenance. RESULTS: All subjects were evaluated for safety, and 13 of 15 subjects completed the treatment protocol. At 1 year post-ASCT, the disease status of enrolled subjects was as follows: five stringent complete responses, one complete response, six very good partial responses, one partial response, and two progressive diseases. The treatment plan was well tolerated, with most grade 3 and 4 AEs being expected hematologic toxicities associated with ASCT. Correlative analysis of the immune microenvironment demonstrated a trend toward reduced regulatory T cells during the first 3 months post-transplant followed by an increase in NK cells and monocytes in patients achieving a complete remission. CONCLUSIONS: This phase 1 clinical trial demonstrates that early introduction of immunotherapy after ASCT is well tolerated and shows promising disease control in patients with MM, accompanied by favorable changes in the immune microenvironment. TRIAL REGISTRATION NUMBER: NCT02655458.

Optimizing the CAR T-Cell Therapy Experience in Multiple Myeloma: Clinical Pearls From an Expert Roundtable.

Chimeric antigen receptor T-cell (CAR-T) therapies offer substantial advancement in the treatment of multiple myeloma (MM). However, the CAR-T therapy process involves complex decision-making that is informed by many variables. This review aims to provide an overview of the patient selection and administration process for CAR-T therapy for MM from the perspective of experienced healthcare providers (HCPs), including considerations for each step in the CAR-T therapy process. Referring HCPs should initiate conversations with HCPs at CAR-T capable centers earlier in the treatment journey, even before patients are eligible for CAR-T therapy, particularly for patients from underserved populations and patients with high-risk disease, to ensure adequate time for logistical planning and patient education. Patient selection for CAR-T therapy may be guided by factors such as performance status, rate of disease progression, and logistical considerations. Some anticancer therapies may affect T-cell fitness and therefore impact CAR-T manufacturing and patient outcomes; however, additional research is needed to confirm this in MM. Bridging therapies should be tailored to the needs of the patient and ideally halted 1 week or longer before CAR-T infusion, contingent upon the agent(s) used. Lymphodepletion regimens may need to be modified for patients with renal insufficiency. Collaboration with HCPs at both the treating and referring centers is important to optimize coordinated care of patients. Collaboration with and guidance from experienced HCPs throughout patient selection, referral, and CAR-T administration is instrumental in optimizing patient outcomes as access to CAR-T therapies expands.

Cellular Mass Response to Therapy Correlates With Clinical Response for a Range of Malignancies.

PURPOSE: Cancer patients with advanced-stage disease have poor prognosis, typically having limited options for efficacious treatment, and genomics-based therapy guidance continues to benefit only a fraction of patients. Next-generation ex vivo approaches, such as cell mass-based response testing (MRT), offer an alternative precision medicine approach for a broader population of patients with cancer, but validation of clinical feasibility and potential impact remain necessary. MATERIALS AND METHODS: We evaluated the clinical feasibility and accuracy of using live-cell MRT to predict patient drug sensitivity. Using a unified measurement workflow with a 48-hour result turnaround time, samples were subjected to MRT after treatment with a panel of drugs in vitro. After completion of therapeutic course, clinical response data were correlated with MRT-based predictions of outcome. Specimens were collected from 104 patients with solid (n = 69) and hematologic (n = 35) malignancies, using tissue formats including needle biopsies, malignant fluids, bone marrow aspirates, and blood samples. Of the 81 (78%) specimens qualified for MRT, 41 (51%) patients receiving physician-selected therapies had treatments matched to MRT. RESULTS: MRT demonstrated high concordance with clinical responses with an odds ratio (OR) of 14.80 (P = .0003 [95% CI, 2.83 to 102.9]). This performance held for both solid and hematologic malignances with ORs of 20.67 (P = .0128 [95% CI, 1.45 to 1,375.57]) and 8.20 (P = .045 [95% CI, 0.77 to 133.56]), respectively. Overall, these results had a predictive accuracy of 80% (P = .0026 [95% CI, 65 to 91]). CONCLUSION: MRT showed highly significant correlation with clinical response to therapy. Routine clinical use is technically feasible and broadly applicable to a wide range of samples and malignancy types, supporting the need for future validation studies.

Prevalence and impact of diabetes on survival of patients with multiple myeloma in different racial groups.

ABSTRACT: Multiple myeloma (MM) is twice as common in Black individuals compared with in White individuals, and diabetes mellitus (DM) disproportionately affects Black patients. Although numerous studies have shown a correlation between DM and MM, this has not been studied in the context of race and in vivo mechanisms. We conducted a retrospective clinical study of 5383 patients with MM of which 15% had DM (White, 12% and Black, 25%). Multivariable Cox models showed reduced overall survival (OS) for patients with DM (hazard ratio, 1.27; 95% confidence interval, 1.11-1.47; P < .001). This appeared to be driven by a marked difference in OS between White patients with and without DM but not in Black patients. In contrast, obesity was associated with better OS in Black patients but not in White patients. To complement this analysis, we assessed MM growth in a genetically engineered immunocompromised nonobese diabetic (Rag1-/-/muscle creatinine kinase promoter expression of a human IGF1R [M] with a lysine [K] to arginine [R] point mutation) mouse model to evaluate the mechanisms linking DM and MM. MM.1S xenografts grew in more Rag1-/-/MKR mice and grew more rapidly in the Rag1-/-/MKR mice compared with in controls. Western blot analysis found that MM1.S xenografts from Rag1-/-/MKR mice had higher phosphorylated S6 ribosomal protein (Ser235/236) levels, indicating greater activation of the mammalian target of rapamycin pathway. Our study is, to our knowledge, the first to evaluate racial differences in DM prevalence and survival in MM, as well as the effect of DM on tumor growth in mouse models. Our results suggest that DM may contribute to the higher incidence of MM in Black patients; and to improve survival in MM, DM management cannot be ignored.

Real-World Utilization of Radiation Therapy in Multiple Myeloma: An Analysis of the Connect MM Registry.

PURPOSE: Radiation therapy (RT) is an important treatment modality for patients with multiple myeloma (MM). Although patients are living longer with MM, they are more likely to have comorbidities related to treatment, such as bone pain; however, RT can provide symptom relief. To date, the characterization of patients who have received RT in the real-world setting has been limited. METHODS AND MATERIALS: The Connect® MM Registry is a large, US multicenter, prospective observational cohort study of adult patients with newly diagnosed MM from mostly community sites. RT utilization and outcomes were analyzed quarterly throughout treatment. Factors associated with RT use were identified via multivariable analysis. RESULTS: A total of 3011 patients were enrolled in the Connect MM Registry with 903 patients (30%) having received RT at any time. There was a significant difference (P < .05) in overall RT use among patients with an Eastern Cooperative Oncology Group performance status of 0 to 1 versus ≥2, International Staging System disease stage I/II versus III, a history of plasmacytoma or a novel agent in their first regimen, and any number of bone lesions or severe osteoporosis/fracture. RT use was associated with having bone lesions or severe osteoporosis (vs not having bone lesions). Additionally, RT use was associated with ethnicity (Hispanic vs not) and Connect MM Registry cohort (cohort 1 [enrolled 2009-2011] vs 2 [enrolled 2012-2016]). In the 6 months before death, increased RT use was associated with increasing number of treatment lines (P < .0001) and high- versus standard-risk disease (per International Myeloma Working Group criteria; P = .0028). CONCLUSIONS: Real-world results from the Connect MM Registry show RT is frequently used and is associated with clinical factors, including performance status and disease stage. Earlier in MM diagnosis, RT may be used as an adjunct to palliate symptoms or delay systemic therapy. Toward the end of life, RT is more frequently used for palliation when treatment options are often limited.

Cellular mechanisms associated with sub-optimal immune responses to SARS-CoV-2 bivalent booster vaccination in patients with Multiple Myeloma.

BACKGROUND: The real-world impact of bivalent vaccines for wild type (WA.1) and Omicron variant (BA.5) is largely unknown in immunocompromised patients with Multiple Myeloma (MM). We characterize the humoral and cellular immune responses in patients with MM before and after receiving the bivalent booster, including neutralizing assays to identify patterns associated with continuing vulnerability to current variants (XBB1.16, EG5) in the current post-pandemic era. METHODS: We studied the humoral and cellular immune responses before and after bivalent booster immunization in 48 MM patients. Spike binding IgG antibody levels were measured by SARS-CoV-2 spike binding ELISA and neutralization capacity was assessed by a SARS-CoV-2 multi-cycle microneutralization assays to assess inhibition of live virus. We measured spike specific T-cell function using the QuantiFERON SARS-CoV-2 (Qiagen) assay as well as flow-cytometry based T-cell. In a subset of 38 patients, high-dimensional flow cytometry was performed to identify immune cell subsets associated with lack of humoral antibodies. FINDINGS: We find that bivalent vaccination provides significant boost in protection to the omicron variant in our MM patients, in a treatment specific manner. MM patients remain vulnerable to newer variants with mutations in the spike portion. Anti-CD38 and anti-BCMA therapies affect the immune machinery needed to produce antibodies. INTERPRETATION: Our study highlights varying immune responses observed in MM patients after receiving bivalent COVID-19 vaccination. Specifically, a subgroup of MM patients undergoing anti-CD38 and anti-BCMA therapy experience impairment in immune cells such DCs, B cells, NK cells and TFH cells, leading to an inability to generate adequate humoral and cellular responses to vaccination. FUNDING: National Cancer Institute (National Institutes of Health), National Institute of Allergy and Infectious Diseases (National Institutes of Health), NCI Serological Sciences Network for COVID-19 (SeroNet) and The Icahn School of Medicine at Mount Sinai.

IVIg Use Associated with Ten-Fold Reduction of Serious Infections in Multiple Myeloma Patients Treated with Anti-BCMA Bispecific Antibodies.

BCMA-targeted bispecific antibodies (BiAb) are efficacious in relapsed/refractory multiple myeloma; however, serious infections have emerged as important toxicities. In this retrospective study, we characterized all infections and their risk factors, and evaluated the impact of infection prophylaxis in patients treated with BCMA-targeted BiAbs. Among 37 patients, 15 (41%) experienced a grade 3-5 infection, with two infection-related deaths during deep remissions. Most (84%) infections occurred during disease remissions. The cumulative probability of grade 3-5 infection increased over time with no plateau. Among responders (n = 26), profound hypogammaglobulinemia occurred in 100% and continued throughout the entire duration of treatment. During periods when patients were receiving intravenous immunoglobulin (IVIg), the rate of grade 3-5 infections was 90% lower than during observation (incidence rate ratio, 0.10; 95% confidence interval, 0.01-0.80; P = 0.0307). No other risk factors for infection were identified. This study demonstrates that profound hypogammaglobulinemia is universal with BCMA-targeted BiAbs, with intravenous immunoglobulin potentially abrogating most of the infection risk. SIGNIFICANCE: To the best of our knowledge, this is the first study to comprehensively analyze risk factors and mitigation strategies to prevent infections in myeloma patients receiving anti-BCMA bispecific antibodies. Profound and prolonged hypogammaglobulinemia was universal among responders, while immunoglobulin replacement was associated with 90% lower rates of grade 3-5 infections. See related commentary by Garfall and Stadtmauer, p. 427 . This article is featured in Selected Articles from This Issue, p. 419.

Ciltacabtagene Autoleucel in Patients With Prior Allogeneic Stem Cell Transplant in the CARTITUDE-1 Study.

BACKGROUND: Patients with prior allogeneic stem cell transplant (alloSCT) are typically excluded from trials of chimeric antigen receptor (CAR) T cell therapies, because their engineered cells may include allogeneic T cells. Ciltacabtagene autoleucel (cilta-cel) demonstrated early, deep, durable responses and manageable safety in heavily pretreated relapsed/refractory multiple myeloma patients. We retrospectively analyzed patients who received alloSCT prior to cilta-cel in CARTITUDE-1. PATIENTS AND METHODS: Patients eligible for CARTITUDE-1 were ≥18 years, had ≥3 prior lines of therapy (LOT) or were double refractory to a proteasome inhibitor (PI) and immunomodulatory drug (IMiD) and had received a PI, IMiD, and anti-CD38 antibody. Patients with active graft-versus-host disease (GVHD) or had alloSCT within 6 months before apheresis were excluded. Patients received cilta-cel 5 to 7 days after lymphodepletion. RESULTS: Patients (N = 7) received median 9 prior LOTs (range, 6-14); median time since alloSCT was 5.1 years (range, 2.7-6.2). At median follow-up 27.7 months after cilta-cel infusion, overall response rate was 85.7% (n = 6). The safety profile was generally consistent with patients without alloSCT as prior therapy (cytokine release syndrome, 85.7% vs. 95.6%, respectively; immune effector cell-associated neurotoxicity syndrome, 14.3% vs. 16.7%). One patient with prior alloSCT had grade 3 movement and neurocognitive treatment-emergent adverse events/parkinsonism. No GVHD cases were reported. Two patients died due to adverse events (treatment-related lung abscess; unrelated liver failure). CONCLUSION: Cilta-cel efficacy and safety were comparable between CARTITUDE-1 patients with and without prior alloSCT. Additional studies are needed to fully elucidate the suitability of CAR-T cell therapy in the post-alloSCT setting.

Association of Selinexor Dose Reductions With Clinical Outcomes in the BOSTON Study.

BACKGROUND: Dose modifications in response to adverse events (AEs) can maintain tumor response and improve therapy tolerability. We conducted a post-hoc analysis of the efficacy and safety of reduced selinexor doses in the BOSTON trial (NCT03110562). PATIENTS AND METHODS: Efficacy, safety, and quality of life (QoL) in 195 patients with relapsed/refractory multiple myeloma randomized to once-weekly (QW) selinexor (100 mg), QW subcutaneous bortezomib (1.3 mg/m2), and twice-weekly dexamethasone (20 mg) were compared between patients with dose reductions and those without. RESULTS: In total, 126 patients (65%) had selinexor dose reductions (median dose 71.4 mg/wk). In patients with dose reductions versus those without median progression-free survival was 16.6 months (95% CI 12.9-not evaluable [NE]) versus 9.2 months [95% CI 6.8-15.5]), overall response rate was 81.7% (95% CI 73.9-88.1%) versus 66.7% (95% CI 54.3-77.6%), ≥very good partial response was (51.6% [95% CI 42.5-60.6%] vs. 31.9% [95% CI 21.2-44.2]), median duration of response was not reached (95% CI 13.8-NE) versus 12.0 months (95% CI 8.3-NE), and time to next treatment was 22.6 months (95% CI 14.6-NE) versus 10.5 months (95% CI 6.3-18.2). Mean best change from baseline on the EORTC QLQ-C30 Global Health Status/QoL scale was 10.0 ± 20.5 versus 4.0 ± 20.9. Duration-adjusted AE rates that were lower after selinexor dose reduction included thrombocytopenia (62.5% before vs. 47.6% after), nausea (31.6% vs. 7.3%), fatigue (28.1% vs. 9.9%), decreased appetite (21.5% vs. 6.4%), anemia (17.9% vs. 10.3%), and diarrhea (12.9% vs. 5.2%). CONCLUSION: Appropriate dose reductions in response to AEs of the 100 mg selinexor starting dose in the BOSTON study were associated with improved efficacy, reduced AE rates and improved QoL.

Idecabtagene vicleucel for relapsed and refractory multiple myeloma: post hoc 18-month follow-up of a phase 1 trial.

Idecabtagene vicleucel (ide-cel) is a B-cell-maturation antigen (BCMA)-directed chimeric antigen receptor T cell therapy. We performed a post hoc analysis of a single-arm phase 1 multicenter study in relapsed/refractory multiple myeloma (CRB-401) (n = 62; median follow-up, 18.1 months). The primary endpoint was safety outcomes, and secondary endpoints included overall response rate (ORR), complete response (CR) and very good partial response (VGPR). The study met its primary endpoint with low rates of grade 3/grade 4 cytokine release syndrome (6.5%) and neurotoxicity (1.6%). ORR was 75.8%; 64.5% achieved VGPR or better and 38.7% achieved CR or stringent CR. Among exploratory endpoints, median duration of response, progression-free survival (PFS) and overall survival were 10.3, 8.8 and 34.2 months, respectively, and ide-cel expansion in blood and bone marrow correlated with clinical efficacy and postinfusion reduction of soluble BCMA. Patients with PFS ≥ 18 months had more naive and less exhausted T cells in apheresis material and improved functional T cell phenotype in the drug product compared with those with less durable responses. These results confirm ide-cel safety, tolerability and efficacy and describe T cell qualities that correlate with durable response. Clinicaltrials.gov identifier : NCT02658929 .