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The document discusses the impact of COVID-19 on patients with relapsed/refractory multiple myeloma (RRMM) in the MajesTEC-1 study evaluating teclistamab. Patients with MM are vulnerable to COVID-19 infection, with high mortality rates reported. The study found that appropriate infection prevention and management are crucial for optimizing outcomes for RRMM patients treated with teclistamab. The findings highlight the importance of immunoglobulin replacement and COVID-19 vaccination in this population. The study provides insights into the impact of COVID-19 on heavily pretreated RRMM patients and emphasizes the need for further research in this area. [Extracted from the article]

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. [ABSTRACT FROM AUTHOR]

Background: Patients with relapsed/refractory multiple myeloma are at increased risk of infection. Infections during treatment with teclistamab, the first B‐cell maturation antigen‐directed bispecific antibody approved for triple‐class–exposed relapsed/refractory multiple myeloma, was examined in the phase 1/2 MajesTEC‐1 study. Methods: Patients (N = 165) received subcutaneous teclistamab 1.5 mg/kg weekly after a step‐up dosing schedule (0.06 mg/kg and 0.3 mg/kg, each separated by 2–4 days). Patients were monitored frequently for infections; prophylaxis and management were per institutional guidelines. Results: At a median follow‐up of 22.8 months (range, 0.3–33.6), infections were reported in 132 patients (80.0%). Grade 3/4 infections occurred in 91 patients (55.2%), including COVID‐19 (21.2%), respiratory infections (19.4%), Pneumocystis jirovecii pneumonia (4.2%), viral infections (4.2%), and gastrointestinal infections (1.2%). Twenty‐one patients died from infections (18 from COVID‐19). Median time to first onset of any‐grade and grade 3 to 5 infections was 1.7 and 4.2 months, respectively. Overall, 70.9% of patients had ≥1 postbaseline immunoglobulin G (IgG) level <400 mg/dL; median time to IgG <400 mg/dL was 1.2 months (range, 0.2–19.8) and 46.1% received ≥1 dose of IgG replacement. Grade 3/4 neutropenia occurred in 65.5% of patients (median time to grade ≥3 neutropenia/febrile neutropenia was 2.3 months [range, 0–18.1]). Conclusion: Based on the infection profile of B‐cell maturation antigen–targeted bispecific antibodies such as teclistamab, it is recommended that clinicians and patients remain vigilant for a range of infection types throughout treatment to facilitate prompt intervention. Appropriate screening, prophylaxis, and management of infections, hypogammaglobulinemia, and neutropenia are important. Clinical trial registration: NCT03145181/NCT04557098 (ClinicalTrials.gov) Plain Language Summary: Before starting teclistamab, patients should be up to date with vaccinations (including COVID‐19) and screened for hepatitis B and C and HIV. Teclistamab should not be given to patients with any active infections.Prophylactic antimicrobials should be administered per institutional guidelines. Prophylaxis for Pneumocystis jirovecii pneumonia and herpes simplex/varicella zoster virus is recommended during teclistamab treatment.Close monitoring of infections and immunoglobulin G (IgG) levels should continue throughout teclistamab treatment. IgG replacement (administered every 3–6 weeks) should be used to maintain IgG ≥400 mg/dL. Growth factors should be considered for grade ≥3 neutropenia with infection/fever and grade 4 neutropenia. In the MajesTEC‐1 study of the B‐cell maturation antigen × CD3‐bispecific antibody teclistamab in heavily pretreated patients with relapsed or refractory multiple myeloma, infections occurred in 80.0% of patients overall at a median follow‐up of 22.8 months (range, 0.3–33.6); grade 3/4 infections were reported in 55.2% and infection‐related deaths in 12.7%, with median time to first onset of any‐grade and grade 3–5 infections of 1.7 and 4.2 months, respectively. Close monitoring across a range of infection types, appropriate prophylaxis, and prompt intervention were key in ensuring the manageability of infections, hypogammaglobulinemia, and neutropenia during teclistamab treatment, and will be important from a clinical practice perspective. [ABSTRACT FROM AUTHOR]

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 6wb1VFUFJB3zLP3nqMGxNa [ABSTRACT FROM AUTHOR]

Introduction: Teclistamab is the first approved B cell maturation antigen × CD3 bispecific antibody with precision dosing for the treatment of triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). We compared the effectiveness of teclistamab in MajesTEC-1 versus real-world physician's choice of therapy (RWPC) in patients from the prospective, non-interventional LocoMMotion and MoMMent studies. Methods: Patients treated with teclistamab from MajesTEC-1 (N = 165) were compared with an external control arm from LocoMMotion (N = 248) or LocoMMotion + MoMMent pooled (N = 302). Inverse probability of treatment weighting adjusted for imbalances in prognostic baseline characteristics. The relative effect of teclistamab versus RWPC for overall response rate (ORR), very good partial response or better (≥ VGPR) rate, and complete response or better (≥ CR) rate was estimated with an odds ratio using weighted logistic regression transformed into a response-rate ratio (RR) and 95% confidence interval (CI). Weighted proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Results: Baseline characteristics were well balanced between treatment cohorts after reweighting. Patients treated with teclistamab had significantly improved outcomes versus RWPC in LocoMMotion: ORR (RR [95% CI], 2.44 [1.79–3.33]; p < 0.0001), ≥ VGPR (RR 5.78 [3.74–8.93]; p < 0.0001), ≥ CR (RR 113.73 [15.68–825.13]; p < 0.0001), DOR (HR 0.39 [0.24–0.64]; p = 0.0002), PFS (HR 0.48 [0.35–0.64]; p < 0.0001), and OS (HR 0.64 [0.46–0.88]; p = 0.0055). Teclistamab versus RWPC in LocoMMotion + MoMMent also had significantly improved outcomes: ORR (RR 2.41 [1.80–3.23]; p < 0.0001), ≥ VGPR (RR 5.91 [3.93–8.88]; p < 0.0001), ≥ CR (RR 132.32 [19.06–918.47]; p < 0.0001), DOR (HR 0.43 [0.26–0.71]; p = 0.0011), PFS (HR 0.49 [0.37–0.66]; p < 0.0001), and OS (HR 0.69 [0.50–0.95]; p = 0.0247). Conclusion: Teclistamab demonstrated significantly improved effectiveness over RWPC in LocoMMotion ± MoMMent, emphasizing its clinical benefit as a highly effective treatment for patients with TCE RRMM. Trial Registration: MajesTEC-1, ClinicalTrials.gov NCT03145181 (phase 1) and NCT04557098 (phase 2); LocoMMotion, ClinicalTrials.gov NCT04035226; MoMMent, ClinicalTrials.gov NCT05160584. [ABSTRACT FROM AUTHOR]

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 6wb1VFUFJB3zLP3nqMGxNa [ABSTRACT FROM AUTHOR]

Background: Teclistamab, a B‐cell maturation antigen × CD3 bispecific antibody, demonstrated an overall response rate of 63.0% in 165 heavily pretreated patients with relapsed or refractory multiple myeloma in the phase 1/2 MajesTEC‐1 study. Cytokine release syndrome (CRS), a known manifestation of T‐cell redirection, was observed in 119 of 165 patients (72.1%). Methods: Patients received once‐weekly teclistamab 1.5 mg/kg subcutaneously after two step‐up doses (0.06 and 0.3 mg/kg). CRS was graded according to American Society for Transplantation and Cellular Therapy criteria and managed according to the study protocol, including use of tocilizumab and/or steroids. Results: Most cases of CRS occurred during the step‐up dosing schedule of teclistamab and were grade 1 (50.3% of patients) or grade 2 (21.2% of patients); a single case of grade 3 CRS was reported in a patient with concurrent grade 3 pneumonia. All CRS cases resolved and none led to treatment discontinuation. Overall, 33.3% of patients had >1 CRS event; CRS recurrence was reduced when tocilizumab was administered for the first CRS event compared with when it was not (20.0% vs. 62.2%, respectively). Baseline characteristics such as tumor burden and cytokine levels did not appear to predict CRS incidence or severity. Conclusions: Findings of this study support the need for preemptive planning and prompt management of CRS in patients treated with T‐cell–engaging bispecific antibodies. Intervention with tocilizumab for CRS appears to decrease the likelihood of patients experiencing subsequent CRS events without compromising response to teclistamab. Plain language summary: Cytokine release syndrome (CRS), observed in 72.1% of patients treated with teclistamab in the MajesTEC‐1 study, was mostly grade 1 or 2 and manageable, without requiring treatment discontinuation.Most CRS occurred during the step‐up schedule, requiring vigilance during treatment initiation.Ensure fever is resolved and patients have no signs of infection before initiating the teclistamab step‐up schedule or administering the next teclistamab dose, to avoid exacerbating CRS.Tocilizumab reduced the risk of subsequent CRS in patients receiving it for their first CRS event (20.0% vs. 62.2% in those not receiving it), without affecting response to teclistamab.No baseline characteristics, including tumor burden or cytokine levels, appeared to clearly predict for CRS occurrence or severity. In the MajesTEC‐1 study of the B‐cell maturation antigen × CD3 bispecific antibody teclistamab, cytokine release syndrome (CRS) occurred in 72.1% of heavily pretreated patients with relapsed or refractory multiple myeloma. Most cases of CRS occurred during the step‐up dosing schedule of teclistamab and were grade 1 or 2 and manageable; tocilizumab reduced the incidence of subsequent CRS in patients who received it for their first CRS event (20.0% vs. 62.2% in those not receiving it), without affecting response to teclistamab. [ABSTRACT FROM AUTHOR]

Introduction: Patients with triple-class-exposed relapsed/refractory multiple myeloma (TCE-RRMM) have a poor prognosis and limited treatment options. Teclistamab, a B-cell maturation antigen × CD3 bispecific antibody, was studied in patients with TCE-RRMM in the single-arm MajesTEC-1 study. To assess the relative effectiveness of teclistamab versus real-world physician's choice of therapy (RWPC), adjusted comparisons were performed using individual patient data from MajesTEC-1 and LocoMMotion, a prospective study of patients with TCE-RRMM. Methods: An external control arm for MajesTEC-1 was created from patients in LocoMMotion (n = 248; clinical cut-off: November 2, 2021) and compared with treated patients (n = 165) from MajesTEC-1 (teclistamab 1.5 mg/kg weekly; clinical cut-off: March 16, 2022). Inverse probability weighting was used to adjust for imbalances in baseline covariates. For binary endpoints [overall response rate (ORR), very good partial response or better (≥ VGPR) rate, complete response or better (≥ CR)], relative effect of teclistamab versus RWPC was estimated with an odds ratio and relative response rate and 95% confidence interval (CI), derived from weighted logistic regression. Weighted Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% CIs for time-to-event endpoints [duration of response (DOR), progression-free survival (PFS), and overall survival (OS)]. Results: After weighting, baseline characteristics were balanced across cohorts. In adjusted comparisons, teclistamab-treated patients were 2.3-fold, 5.2-fold and 148.3-fold, more likely to reach ORR [response-rate ratio (RR) = 2.31, 95% CI 1.77–2.85, p < 0.0001], ≥ VGPR (RR = 5.19, 95% CI 3.26–7.12, p < 0.0001) and ≥ CR (RR = 148.25, 95% CI 20.63–1065.40, p < 0.0001), respectively, versus patients receiving RWPC. Following adjustment, DOR (HR 0.32, 95% CI 0.19–0.54, p < 0.0001) and PFS (HR 0.48, 95% CI 0.35–0.65, p < 0.0001) were significantly longer with teclistamab versus RWPC. OS was numerically better with teclistamab versus RWPC [HR 0.77 (0.55–1.09), p = 0.1419]. Conclusion: Teclistamab demonstrated improved effectiveness versus RWPC, highlighting its clinical benefit as a novel and effective treatment for patients with TCE-RRMM. Trial Registration: Majest TEC-1, ClinicalTrials.gov NCT04557098; LocoMMotion, ClinicalTrials.gov NCT04035226. [ABSTRACT FROM AUTHOR]

These results indicate that corticosteroid tapering does not diminish DARA SC monotherapy efficacy, as patients who received DARA SC with/without tapering achieved similar efficacy [[3], [15]]. No patients evaluable for daratumumab immunogenicity were positive for anti-daratumumab antibodies, indicating a low risk for immunogenicity for DARA SC with corticosteroid tapering. All patients experienced >=1 TEAE; 21 (50.0%) patients reported a grade >=3 TEAE, and 16 (38.1%) patients experienced a serious TEAE. [Extracted from the article]

Furthermore, patients diagnosed with MM at autopsy ( I n i = 46) and synchronous malignancies within a time interval of 3 months before or after MM diagnosis ( I n i = 237) were excluded. The rapidly evolving treatment landscape of multiple myeloma (MM) has dramatically improved the survival of MM patients over time. In the second model (M2), patients with a PMD were classified as patients (a) with or (b) without receipt of systemic therapy and/or radiotherapy before MM diagnosis. By assessing the impact of an SPM on mortality risk, we observed a higher mortality risk among MM patients with a PMD than MM patients without a PMD. [Extracted from the article]

Chimeric antigen receptor (CAR) T-cell therapies are highly effective for multiple myeloma (MM) but their impressive efficacy is associated with treatment-related neurotoxicities in some patients. In CARTITUDE-1, 5% of patients with MM reported movement and neurocognitive treatment-emergent adverse events (MNTs) with ciltacabtagene autoleucel (cilta-cel), a B-cell maturation antigen-targeted CAR T-cell therapy. We assessed the associated factors for MNTs in CARTITUDE-1. Based on common features, patients who experienced MNTs were characterized by the presence of a combination of at least two variables: high tumor burden, grade ≥2 cytokine release syndrome (CRS) or any grade immune effector cell-associated neurotoxicity syndrome (ICANS) after cilta-cel infusion, and high CAR T-cell expansion/persistence. Strategies were implemented across the cilta-cel development program to monitor and manage patients with MNTs, including enhanced bridging therapy to reduce baseline tumor burden, early aggressive treatment of CRS and ICANS, handwriting assessments for early symptom detection, and extended monitoring/reporting time for neurotoxicity beyond 100 days post-infusion. After successful implementation of these strategies, the incidence of MNTs was reduced from 5% to <1% across the cilta-cel program, supporting its favorable benefit–risk profile for treatment of MM. [ABSTRACT FROM AUTHOR]

The therapeutic monoclonal antibody (t-mAb) daratumumab, used to treat multiple myeloma (MM) patients, interferes with routine, electrophoretic based M-protein diagnostics. Electrophoretic response assessment becomes increasingly difficult when multiple t-mAbs are combined for use in a single patient. This is the first study to address the analytical challenges of M-protein monitoring when multiple t-mAbs are combined. In this proof-of-principle study we evaluate two different methods to monitor M-protein responses in three MM patients, who receive both daratumumab and nivolumab. The double hydrashift assay aims to resolve t-mAb interference on immunofixation. The MS-MRD (mass spectrometry minimal residual disease) assay measures clonotypic peptides to quantitate both M-protein and t-mAb concentrations. After exposure to daratumumab and nivolumab, both t-mAbs become visible on immunofixation electrophoresis (IFE) as two IgG-kappa bands that migrate close to each other at the cathodal end of the γ-region. In case the M-protein co-migrates with these t-mAbs, the observed interference was completely abolished with the double IFE hydrashift assay. In all three patients the MS-MRD assay was also able to distinguish the M-protein from the t-mAbs. Additional advantage of the MS-MRD assay is that this multiplex assay is more sensitive and allows quantitative M-protein-, daratumumab- and nivolumab-monitoring. Daratumumab and nivolumab interfere with electrophoretic M-protein diagnostics. However, the M-protein can be distinguished from both t-mAbs by use of a double hydrashift assay. The MS-MRD assay provides an alternative method that allows sensitive and simultaneous quantitative monitoring of both the M-protein and t-mAbs. [ABSTRACT FROM AUTHOR]

Identification of risk factors for early mortality (EM) in multiple myeloma (MM) patients may contribute to different therapeutic approaches in patients at risk for EM. This population-based study aimed to assess trends in EM and risk factors for EM among MM patients diagnosed in the Netherlands. All MM patients, newly diagnosed between 1989 and 2018, were identified in the Netherlands Cancer Registry. Patients were categorized into three calendar periods (1989–1998, 1999–2008, 2009–2018) and into five age groups (≤65, 66–70, 71–75, 76–80, >80 years). EM was defined as death by any cause ≤180 days post-diagnosis. We included 28,328 MM patients (median age 70 years; 55% males). EM decreased from 22% for patients diagnosed in 1989–1998 to 13% for patients diagnosed in 2009–2018 (P < 0.01) and this decrease was observed among all age groups. Exact causes of death could not be elucidated. Besides patient's age, we found that features related to a more aggressive disease presentation, and patient characteristics reflecting patients' physical condition were predictive of EM. In summary, EM decreased from 1999 onwards. Nevertheless, EM remains high, especially for patients aged >70 years. Therefore, novel strategies should be explored to improve the outcome of patients at risk for EM. [ABSTRACT FROM AUTHOR]

Summary: In this review, two types of soft‐tissue involvement in multiple myeloma are defined: (i) extramedullary (EMD) with haematogenous spread involving only soft tissues and (ii) paraskeletal (PS) with tumour masses arising from skeletal lesions. The incidence of EMD and PS plasmacytomas at diagnosis ranges from 1·7% to 4·5% and 7% to 34·4% respectively. EMD disease is often associated with high‐risk cytogenetics, resistance to therapy and worse prognosis than in PS involvement. In patients with PS involvement a proteasome inhibitor‐based regimen may be the best option followed by autologous stem cell transplantation (ASCT) in transplant eligible patients. In patients with EMD disease who are not eligible for ASCT, a proteasome inhibitor‐based regimen such as lenalidomide‐bortezomib‐dexamethasone (RVD) may be the best option, while for those eligible for high‐dose therapy a myeloma/lymphoma‐like regimen such as bortezomib, thalidomide and dexamethasone (VTD)‐RVD/cisplatin, doxorubicin, cyclophosphamide and etoposide (PACE) followed by SCT should be considered. In both EMD and PS disease at relapse many strategies have been tried, but this remains a high‐unmet need population. [ABSTRACT FROM AUTHOR]

Introduction: Daratumumab is a CD38-targeting monoclonal antibody that has demonstrated clinical benefit for multiple myeloma. Daratumumab inhibition of CD38, which is expressed on immune cell populations and cardiomyocytes, could potentially affect cardiac function. This QTc substudy of the phase 2 CENTAURUS study investigated the potential effect of intravenous daratumumab monotherapy on QTc prolongation and other electrocardiogram (ECG) parameters, including concentration-QTc effect modeling. Methods: Patients had intermediate- or high-risk smoldering multiple myeloma. Patients with QT interval corrected by Fridericia's formula (QTcF) > 470 ms, QRS interval ≥ 110 ms, or PR interval ≥ 200 ms were excluded. Triplicate ECGs were collected at screening, Dose 1, and Dose 8. Analyses of on-treatment ECGs were conducted with a time-matched baseline (primary analysis). By time-point, pharmacokinetic-pharmacodynamic (PK/PD), and outlier analyses were conducted. Results: Of 123 patients in CENTAURUS, 31 were enrolled in the QTc substudy. Daratumumab produced a small increase in heart rate (5–12 beats per minute) of unclear significance. There was a small but clinically insignificant effect on QTc, as measured by both time-matched time-point and PK/PD analyses. The primary analysis demonstrated a maximum mean increase in QTcF of 9.1 ms (90% 2-sided upper confidence interval [CI], 14.1 ms). The primary PK/PD analysis predicted a maximum QTcF increase of 8.5 ms (90% 2-sided upper CI, 13.5 ms). No patient had an abnormal U wave, a new QTcF > 500 ms, or > 60 ms change from baseline for QTcF. Conclusion: Analysis of ECG intervals and concentration-QTc relationships showed a small but clinically insignificant effect of daratumumab. Trial Registration: ClinicalTrials.gov Identifier: NCT02316106. [ABSTRACT FROM AUTHOR]

In the era of highly promising novel targeted-immunotherapy strategies for multiple myeloma (MM), the first series of clinical trials with CAR T-cells targeting the plasma cell-specific B-cell maturation antigen (BCMA) have shown excellent response rates. In the long-term, however, MM appears to escape the therapy likely due to initial low and heterogeneous expression or downregulation of BCMA expression. Several other molecules targeted by CAR T-cells in MM are expressed at high levels on MM cells, but many of these attractive targets are also expressed on various, sometimes vital non-malignant cells, posing major risks for on-target, off-tumor side effects. CAR T-cell therapy for MM therefore faces two urgent challenges: (i) improving the efficacy of BCMA CAR T-cells and (ii) establishing a MM-selectivity even when CAR T-cells are directed against not entirely MM-specific target antigens. In this review, we will outline the current attempts to tackle these challenges, with a specific focus on how dual CAR targeting might be applied to tackle both issues. [ABSTRACT FROM AUTHOR]

The introduction of proteasome inhibitors (PI) and immunomodulatory drugs (IMiD) has markedly increased the survival of multiple myeloma (MM) patients. Also, the unconjugated monoclonal antibodies (mAb) daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7) have revolutionized MM treatment given their clinical efficacy and safety, illustrating the potential of targeted immunotherapy as a powerful treatment strategy for MM. Nonetheless, most patients eventually develop PI-, IMiD-, and mAb-refractory disease because of the selection of resistant MM clones, which associates with a poor prognosis. Accordingly, these patients remain in urgent need of new therapies with novel mechanisms of action. In this respect, mAbs or mAb fragments can also be utilized as carriers of potent effector moieties to specifically target surface antigens on cells of interest. Such immunoconjugates have the potential to exert anti-MM activity in heavily pretreated patients due to their distinct and pleiotropic mechanisms of action. In addition, the fusion of highly cytotoxic compounds to mAbs decreases the off-target toxicity, thereby improving the therapeutic window. According to the effector moiety, immunoconjugates are classified into antibody-drug conjugates, immunotoxins, immunocytokines, or radioimmunoconjugates. This review will focus on the mechanisms of action, safety and efficacy of several promising immunoconjugates that are under investigation in preclinical and/or clinical MM studies. We will also include a discussion on combination therapy with immunoconjugates, resistance mechanisms, and future developments. [ABSTRACT FROM AUTHOR]

Recent clinical advances with chimeric antigen receptor (CAR) T cells have led to the accelerated clinical approval of CD19-CARs to treat acute lymphoblastic leukemia. The CAR T cell therapy is nevertheless associated with toxicities, especially if the CARs are not entirely tumor-specific. Therefore, strategies for controlling the CAR T cell activity are required to improve their safety profile. Here, by using the multiple myeloma (MM)-associated CD38 molecule as target molecule, we tested the feasibility and utility of a doxycycline (DOX) inducible Tet-on CD38-CAR design to control the off-target toxicities of CAR T cells. Using CARs with high affinity to CD38, we demonstrate that this strategy allows the proper induction of CD38-CARs and CAR-mediated T cell cytotoxicity in a DOX-dose dependent manner. Especially when the DOX dose was limited to 10ng/ml, its removal resulted in a relatively rapid decay of CAR- related off-tumor effects within 24 hours, indicating the active controllability of undesired CAR activity. This Tet-on CAR design also allowed us to induce the maximal anti-MM cytotoxic activity of affinity-optimized CD38-CAR T cells, which already display a low toxicity profile, hereby adding a second level of safety to these cells. Collectively, these results indicate the possibility to utilize this DOX inducible CAR-design to actively regulate the CAR-mediated activities of therapeutic T cells. We therefore conclude that the Tet-on system may be more advantageous above suicide-genes to control the potential toxicities of CAR T cells without the need to destroy them permanently. [ABSTRACT FROM AUTHOR]

Introduction: Multiple myeloma (MM) is generally an incurable hematological malignancy with heterogeneous overall survival rates ranging from a few months to more than 10 years. Survival is especially poor for patients who developed disease that is refractory to immunomodulatory drugs and proteasome inhibitors.Areas covered: This review will discuss the importance of CD38-targeting antibodies for the treatment of MM patients to improve their outcome.Expert commentary: Intense immuno-oncological laboratory research has resulted in the development of functionally active monoclonal antibodies against cell surface markers present on MM cells. In this respect, CD38-targeting antibodies such as daratumumab, MOR202, and isatuximab, have high single agent activity in heavily pretreated MM patients by virtue of their pleiotropic mechanisms of action including Fc-dependent effector mechanisms and immunomodulatory activities. Importantly, CD38-targeting antibodies are well tolerated, with infusion reactions as most frequent adverse event. Altogether, this makes them attractive combination partners with other anti-MM agents. Daratumumab is already approved as monotherapy and in combination with lenalidomide-dexamethasone as well as bortezomib-dexamethasone in pretreated MM patients. Furthermore, results from studies evaluating CD38-targeting antibodies in newly diagnosed MM patients are also promising, indicating that CD38-targeting antibodies will be broadly used in MM, resulting in further improvements in survival. [ABSTRACT FROM AUTHOR]

Background: Monoclonal antibodies are promising antimyeloma treatments. As immunoglobulins, monoclonal antibodies have the potential to be identified by serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). Therapeutic antibody interference with standard clinical SPE and IFE can confound the use of these tests for response assessment in clinical trials and disease monitoring. Methods: To discriminate between endogenous myeloma protein and daratumumab, a daratumumab-specific immunofixation electrophoresis reflex assay (DIRA) was developed using a mouse anti-daratumumab antibody. To evaluate whether anti-daratumumab bound to and shifted the migration pattern of daratumumab, it was spiked into daratumumab-containing serum and resolved by IFE/SPE. The presence (DIRA positive) or absence (DIRA negative) of residual M-protein in daratumumab-treated patient samples was evaluated using predetermined assessment criteria. DIRA was evaluated for specificity, limit of sensitivity, and reproducibility. Results: In all of the tested samples, DIRA distinguished between daratumumab and residual M-protein in commercial serum samples spiked with daratumumab and in daratumumab-treated patient samples. The DIRA limit of sensitivity was 0.2 g/L daratumumab, using spiking experiments. Results from DIRA were reproducible over multiple days, operators, and assays. The anti-daratumumab antibody was highly specific for daratumumab and did not shift endogenous M-protein. Conclusions: As the treatment of myeloma evolves to incorporate novel monoclonal antibodies, additional solutions will be needed for clinical monitoring of patient responses to therapeutic regimens. In the interim, assays such as DIRA can inform clinical outcomes by distinguishing daratumumab from endogenous M-protein by IFE. [ABSTRACT FROM AUTHOR]

Daratumumab is a fully human anti-CD38 IgG1-κ monoclonal antibody (mAb) currently being evaluated in several Phase 2 and 3 clinical studies for the treatment of multiple myeloma (MM). In this clinical case study we demonstrate that daratumumab can be detected as an individual monoclonal band in serum immunofixation electrophoresis (IFE). M-protein follow-up by IFE is part of the International Myeloma Working Group (IMWG) criteria to assess treatment response. Therefore, it is crucial that the daratumumab band is not confused with the endogenous M-protein of the patient during IFE interpretation. Moreover, a significant number of IgG-κ M-proteins co-migrate with daratumumab. Co-migration introduces a bias in the M-protein quantification since pharmacokinetic studies show that daratumumab peak plasma concentrations reach up to 1 g/L. More importantly, co-migration can mask clearance of the M-protein by IFE which is necessary for classification of complete response by IMWG criteria (negative serum IFE). For optimal M-protein monitoring the laboratory specialist needs to be informed when patients receive daratumumab, and it is essential that the laboratory specialist is aware that a slow migrating band in the γ-region in those patients may be derived from the daratumumab. A daratumumab specific IFE reflex assay (DIRA) has been developed and can be utilized to abrogate interference. The here described mAb interference is not limited to daratumumab, and as therapeutic antibodies gain approval and enter into common clinical practice, laboratory specialists will need additional processes to characterize IFE interference and distinguish endogenous M-protein from therapeutic antibodies. [ABSTRACT FROM AUTHOR]

Lenalidomide is an amino-substituted derivative of thalidomide with direct antiproliferative and cytotoxic effects on the myeloma tumor cell, as well as antiangiogenic activity and immunomodulatory effects. Together with the introduction of bortezomib and thalidomide, lenalidomide has significantly improved the survival of patients with relapsed and refractory myeloma. The most common adverse events associated with lenalidomide include fatigue, skin rash, thrombocytopenia, and neutropenia. In addition, when lenalidomide is combined with dexamethasone or other conventional cytotoxic agents, there is an increase in the incidence of venous thromboembolic events. There is now evidence that continued treatment with lenalidomide has a significant impact on survival by improving the depth and duration of response. This highlights the value of adverse event management and appropriate dose adjustments to prevent toxicity, and of allowing continued treatment until disease progression. In this review, we will discuss the different lenalidomide-based treatment regimens for patients with relapsed/refractory myeloma. This is accompanied by recommendations of how to manage and prevent adverse events associated with lenalidomide-based therapy. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) patients eventually develop multi-drug-resistant disease with poor survival. Hence, the development of novel treatment strategies is of great importance. Recently, different classes of immunotherapeutic agents have shown great promise in heavily pre-treated MM, including T cell-redirecting bispecific antibodies (BsAbs). These BsAbs simultaneously interact with CD3 on effector T cells and a tumor-associated antigen on MM cells, resulting in redirection of T cells to MM cells. This leads to the formation of an immunologic synapse, the release of granzymes/perforins, and subsequent tumor cell lysis. Several ongoing phase 1 studies show substantial activity and a favorable toxicity profile with BCMA-, GPRC5D-, or FcRH5-targeting BsAbs in heavily pre-treated MM patients. Resistance mechanisms against BsAbs include tumor-related features, T cell characteristics, and impact of components of the immunosuppressive tumor microenvironment. Various clinical trials are currently evaluating combination therapy with a BsAb and another agent, such as a CD38-targeting antibody or an immunomodulatory drug (e.g., pomalidomide), to further improve response depth and duration. Additionally, the combination of two BsAbs, simultaneously targeting two different antigens to prevent antigen escape, is being explored in clinical studies. The evaluation of BsAbs in earlier lines of therapy, including newly diagnosed MM, is warranted, based on the efficacy of BsAbs in advanced MM. [ABSTRACT FROM AUTHOR]

Simple Summary: The CD38-targeting antibody daratumumab has marked activity in multiple myeloma through direct anti-tumor effects and immunomodulatory activity. However, eventually most patients will develop daratumumab-refractory disease. We hypothesized that daratumumab-resistance could be reversed by the addition of an inhibitor of the PD-1/PD-L1 signaling pathway, resulting in improved T- and NK-cell mediated anti-tumor immune responses. We therefore performed a phase 2 study to investigate the efficacy and safety of adding the PD-L1 checkpoint inhibitor durvalumab to daratumumab at the time of daratumumab failure. The toxicity profile of the daratumumab/durvalumab combination was acceptable, but none of the 18 enrolled patients achieved a clinical response. Immunomonitoring of bone marrow samples at baseline and during treatment showed a reduction of regulatory T-cell numbers and a decrease in the proportion of T-cells expressing LAG3 and CD8+ T-cells expressing TIM-3, whereas tumor cell characteristics were not affected. These results indicate that co-targeting PD-L1 at the time of daratumumab failure is insufficient to reverse daratumumab-resistance. Daratumumab is active both as a single agent and in combination with other agents in multiple myeloma (MM) patients. However, the majority of patients will develop daratumumab-refractory disease, which carries a poor prognosis. Since daratumumab also has immunomodulatory effects, addition of the PD-L1 blocking antibody durvalumab at the time of progression may reverse daratumumab-resistance. The efficacy and safety of daratumumab and durvalumab in daratumumab-refractory relapsed/refractory MM patients was evaluated in this prospective, single-arm phase 2 study (NCT03000452). None of the 18 enrolled patients achieved PR or better. The frequency of serious adverse events was 38.9%, with one patient experiencing an immune related adverse event (grade 2 hyperthyroidism). No infusion-related reactions were observed. Analysis of tumor- and immune cell characteristics was performed on bone marrow samples obtained at baseline and during treatment. Daratumumab combined with durvalumab reduced the frequency of regulatory T-cells and decreased the proportion of T-cells expressing LAG3 and CD8+ T-cells expressing TIM-3, without altering T- and NK-cell frequencies. Durvalumab did not affect tumor cell characteristics associated with daratumumab resistance. In conclusion, the addition of durvalumab to daratumumab following development of daratumumab-resistance was associated with an acceptable toxicity profile, but was not effective. This indicates that inhibition of the PD-1/PD-L1 signaling pathway at the time of daratumumab-resistance is insufficient to reverse daratumumab-resistance. [ABSTRACT FROM AUTHOR]

Simple Summary: Monoclonal antibodies represent a major therapeutic progress in multiple myeloma during the last decade. The use of antibodies as well as antibody drug conjugates has changed the treatment landscape rapidly. The intent of this paper is to summarize the current major results of monoclonal antibody treatments in multiple myeloma. Multiple myeloma is the second most common hematologic malignancy. Current treatment strategies are mainly based on immunomodulatory drugs, proteasome inhibitors or combination of both. Novel agents added to these backbone treatments represent a promising strategy in treatment of newly diagnosed as well as relapsed and refractory multiple myeloma patients. In this respect, the incorporation of monoclonal antibodies into standard-of-care regimens markedly improved prognosis of myeloma patients during the last years. More specifically, monoclonal anti-CD38 antibodies, daratumumab and isatuximab, have been implemented into treatment strategies from first-line treatment to refractory disease. In addition, the monoclonal anti-SLAM-F7 antibody elotuzumab in combination with immunomodulatory drugs has improved the clinical outcomes of patients with relapsed/refractory disease. Belantamab mafodotin is the first approved antibody drug conjugate directed against B cell maturation antigen and is currently used as a monotherapy for patients with advanced disease. This review focuses on clinical efficacy and safety of monoclonal antibodies as well as antibody drug conjugates in multiple myeloma. [ABSTRACT FROM AUTHOR]

Due to the CD1d restricted recognition of altered glycolipids, Vα24-invariant natural killer T (iNKT) cells are excellent tools for cancer immunotherapy with a significantly reduced risk for graft-versus-host disease when applied as off-the shelf-therapeutics across Human Leukocyte Antigen (HLA) barriers. To maximally harness their therapeutic potential for multiple myeloma (MM) treatment, we here armed iNKT cells with chimeric antigen receptors (CAR) directed against the MM-associated antigen CD38 and the plasma cell specific B cell maturation antigen (BCMA). We demonstrate that both CD38- and BCMA-CAR iNKT cells effectively eliminated MM cells in a CAR-dependent manner, without losing their T cell receptor (TCR)-mediated cytotoxic activity. Importantly, iNKT cells expressing either BCMA-CARs or affinity-optimized CD38-CARs spared normal hematopoietic cells and displayed a Th1-like cytokine profile, indicating their therapeutic utility. While the costimulatory domain of CD38-CARs had no influence on the cytotoxic functions of iNKT cells, CARs containing the 4-1BB domain showed a better expansion capacity. Interestingly, when stimulated only via CD1d+ dendritic cells (DCs) loaded with α-galactosylceramide (α-GalCer), both CD38- and BCMA-CAR iNKT cells expanded well, without losing their CAR- or TCR-dependent cytotoxic activities. This suggests the possibility of developing an off-the-shelf therapy with CAR iNKT cells, which might even be boostable in vivo by administration α-GalCer pulsed DCs. [ABSTRACT FROM AUTHOR]

The article discusses the effectiveness of using the combination of Lenalidomide (Revlimid) with continuous oral cyclophosphamide (endoxan) and prednisone (REP) in lenalidomide/dexamethasone-refractory myeloma. It presents tables showing response of Revlimid, cyclophosphamide and prednisone on the patients. It concludes that high activity with good tolerability in lenalidomide/dexamethasone-refractory myeloma is witnessed due to the use of REP regimen with its fully oral formulation.

Simple Summary: The CD38-targeting antibody daratumumab mediates its anti-myeloma activities not only through direct effects on tumor cells, but also by its effects on T-cell immunity through depletion of CD38+ immune suppressor cells. We hypothesized that combining daratumumab with modulators of other potent immune inhibitory pathways, such as the PD-1/PD-L1 axis, may further improve its efficacy. We show that during MM progression there is increased expression of the PD-1/PD-L1 pathway components in the bone marrow microenvironment. Although nivolumab (a PD-1 checkpoint inhibitor) moderately increased T-cell frequencies in ex vivo experiments with bone marrow samples from MM patients, no single agent activity was observed, and addition of nivolumab did not enhance the activity of daratumumab in these short-term assays. However, with a longer treatment duration, in mouse experiments, we demonstrate that anti-CD38 and anti-PD-1 antibodies synergize to eradicate MM cells. In addition, our results suggest that this combined immunotherapeutic approach may also be beneficial in other CD38-positive malignancies. The CD38-targeting antibody daratumumab mediates its anti-myeloma activities not only through Fc-receptor-dependent effector mechanisms, but also by its effects on T-cell immunity through depletion of CD38+ regulatory T-cells, regulatory B-cells, and myeloid-derived suppressor cells. Therefore, combining daratumumab with modulators of other potent immune inhibitory pathways, such as the PD-1/PD-L1 axis, may further improve its efficacy. We show that multiple myeloma (MM) cells from relapsed/refractory patients have increased expression of PD-L1, compared to newly diagnosed patients. Furthermore, PD-1 is upregulated on T-cells from both newly diagnosed and relapsed/refractory MM patients, compared to healthy controls. In short-term experiments with bone marrow samples from MM patients, daratumumab-mediated lysis was mainly associated with the MM cells' CD38 expression levels and the effector (NK-cells/monocytes/T-cells)-to-target ratio, but not with the PD-L1 expression levels or PD-1+ T-cell frequencies. Although PD-1 blockade with nivolumab did not affect MM cell viability or enhanced daratumumab-mediated lysis in short-term ex vivo experiments, nivolumab resulted in a mild but clear increase in T-cell numbers. Moreover, with a longer treatment duration, PD-1 blockade markedly improved anti-CD38 antibody-mediated cytotoxicity in vivo in murine CD38+ tumor models. In conclusion, dual targeting of CD38 and PD-1 may represent a promising strategy for treating MM and other CD38-positive malignancies. [ABSTRACT FROM AUTHOR]

Antibodies targeting CD38 are rapidly changing the treatment landscape of multiple myeloma (MM). CD38−directed antibodies have several mechanisms of action. Fc−dependent immune effector mechanisms include complement-dependent cytotoxicity (CDC), antibody−dependent cell−mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and apoptosis. In addition, direct effects and immunomodulatory effects contribute to the efficacy of CD38−directed antibodies. Daratumumab, the first−in−class anti−CD38 monoclonal antibody, is now part of standard treatment regimens of both newly diagnosed as well as relapsed/refractory MM patients. The FDA has recently approved isatuximab in combination with pomalidomide and dexamethasone for relapsed/refractory MM patients after at least two prior therapies. Further, the other CD38−targeting antibodies (i.e., MOR202 and TAK-079) are increasingly used in clinical trials. The shift to front-line treatment of daratumumab will lead to an increase in patients refractory to CD38 antibody therapy already after first−line treatment. Therefore, it is important to gain insight into the mechanisms of resistance to CD38−targeting antibodies in MM, and to develop strategies to overcome this resistance. In the current review, we will briefly describe the most important clinical data and mechanisms of action and will focus in depth on the current knowledge on mechanisms of resistance to CD38-targeting antibodies and potential strategies to overcome this. [ABSTRACT FROM AUTHOR]

During a time span of just a few years, the CD38 antibody, daratumumab, has been established as one of the most important new drugs for the treatment of multiple myeloma, both in the relapsed/refractory setting and, more recently, as a first-line treatment. Although much is known about the pleiotropic modes of action of daratumumab, we are still not sure how to use it in an optimal manner. Daratumumab targets CD38 on myeloma cells and a high level of CD38 expression facilitates complement-mediated cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). Since the expression of CD38 by myeloma cells is downregulated during treatment with daratumumab, it may seem reasonable to introduce a wash-out period and retreat with daratumumab at a later time point when CD38 expression has recovered in order to gain the maximum benefit of daratumumab's capacity to kill myeloma cells by CDC, ADCC and ADCP. In other aspects, CD38 seems to serve as a survival factor for myeloma cells by facilitating protective myeloma cell–stromal-cell interactions, contributing to the formation of nanotubes that transfer mitochondria from the stromal cells to myeloma cells, boosting myeloma cell proliferation and survival and by generation of immunosuppressive adenosine in the bone marrow microenvironment. In addition, continuous exposure to daratumumab may keep immune suppressor cells at a low level, which boosts the anti-tumor activity of T-cells. In fact, one may speculate if in the early phase of treatment of a myeloma patient, the debulking effects of daratumumab achieved by CDC, ADCC and ADCP are more important while at a later stage, reprogramming of the patient's own immune system and certain metabolic effects may take over and become more essential. This duality may be reflected by what we often observe when we watch the slope of the M-protein from myeloma patients responding to daratumumab: A rapid initial drop followed by a slow decline of the M-protein during several months or even years. Ongoing and future clinical trials will teach us how to use daratumumab in an optimal way. [ABSTRACT FROM AUTHOR]