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.).

Incidence, timing, and management of infections in patients receiving teclistamab for the treatment of relapsed/refractory multiple myeloma in the MajesTEC-1 study.

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.

BAG3 localizes to mitochondria in cardiac fibroblasts and regulates mitophagy.

The co-chaperone Bcl2-associated athanogene 3 (BAG3) is a central node in protein quality control in the heart. In humans and animal models, decreased BAG3 expression is associated with cardiac dysfunction and dilated cardiomyopathy. Although previous studies focused on BAG3 in cardiomyocytes, cardiac fibroblasts are also critical drivers of pathologic remodeling. Yet, the role of BAG3 in cardiac fibroblasts is almost completely unexplored. Here, we show that BAG3 is expressed in primary rat neonatal cardiac fibroblasts and preferentially localizes to mitochondria. Knockdown of BAG3 reduces mitophagy and enhances fibroblast activation, which is associated with fibrotic remodeling. Heat shock protein 70 (Hsp70) is a critical binding partner for BAG3 and inhibiting this interaction in fibroblasts using the drug JG-98 decreased autophagy, decreased mitofusin-2 expression, and disrupted mitochondrial morphology. Together, these data indicate that BAG3 is expressed in cardiac fibroblasts, where it facilitates mitophagy and promotes fibroblast quiescence. This suggests that depressed BAG3 levels in heart failure may exacerbate fibrotic pathology, thus contributing to myocardial dysfunction through sarcomere-independent pathways.NEW & NOTEWORTHY We report BAG3's localization to mitochondria and its role in mitophagy for the first time in primary ventricular cardiac fibroblasts. We have also collected the first evidence showing that loss of BAG3 increases cardiac fibroblast activation into myofibroblasts, which are major drivers of cardiac fibrosis and pathological remodeling during heart disease.

GSK-3ß Localizes to the Cardiac Z-Disc to Maintain Length Dependent Activation.

BACKGROUND: Altered kinase localization is gaining appreciation as a mechanism of cardiovascular disease. Previous work suggests GSK-3ß (glycogen synthase kinase 3ß) localizes to and regulates contractile function of the myofilament. We aimed to discover GSK-3ß's in vivo role in regulating myofilament function, the mechanisms involved, and the translational relevance. METHODS: Inducible cardiomyocyte-specific GSK-3ß knockout mice and left ventricular myocardium from nonfailing and failing human hearts were studied. RESULTS: Skinned cardiomyocytes from knockout mice failed to exhibit calcium sensitization with stretch indicating a loss of length-dependent activation (LDA), the mechanism underlying the Frank-Starling Law. Titin acts as a length sensor for LDA, and knockout mice had decreased titin stiffness compared with control mice, explaining the lack of LDA. Knockout mice exhibited no changes in titin isoforms, titin phosphorylation, or other thin filament phosphorylation sites known to affect passive tension or LDA. Mass spectrometry identified several z-disc proteins as myofilament phospho-substrates of GSK-3ß. Agreeing with the localization of its targets, GSK-3ß that is phosphorylated at Y216 binds to the z-disc. We showed pY216 was necessary and sufficient for z-disc binding using adenoviruses for wild-type, Y216F, and Y216E GSK-3ß in neonatal rat ventricular cardiomyocytes. One of GSK-3ß's z-disc targets, abLIM-1 (actin-binding LIM protein 1), binds to the z-disc domains of titin that are important for maintaining passive tension. Genetic knockdown of abLIM-1 via siRNA in human engineered heart tissues resulted in enhancement of LDA, indicating abLIM-1 may act as a negative regulator that is modulated by GSK-3ß. Last, GSK-3ß myofilament localization was reduced in left ventricular myocardium from failing human hearts, which correlated with depressed LDA. CONCLUSIONS: We identified a novel mechanism by which GSK-3ß localizes to the myofilament to modulate LDA. Importantly, z-disc GSK-3ß levels were reduced in patients with heart failure, indicating z-disc localized GSK-3ß is a possible therapeutic target to restore the Frank-Starling mechanism in patients with heart failure.

An Analysis of Clinical Outcomes of Exploratory Pediatric Metformin Ingestions Reported to the Texas Poison Center Network From 2011 to 2021.

Background: Poison centers develop triage threshold guidelines for pediatric metformin ingestions. Our network uses 1700 mg, or 85 mg/kg. Objective: To describe the dose, clinical course, and outcomes for inadvertent metformin ingestions in children 5 years old and younger reported to our statewide poison center network. Methods: We searched the poison center database 2011 to 2021 for metformin ingestions in patients 5 years and younger. Variables included age, sex, weight, dose, symptoms, outcome, and more. We used descriptive statistics with medians and interquartile ranges (IQR) for continuous variables. Results: Of 669 cases, exposures by age were 208 (31.1%) 1 to 2 years, and 275 (41.1%) 2 years. Weight was recorded in 342 (51.1%) (median 13.5 kg; IQR: 3.7 kg), and dose in 149 (22.3%) (median 500 mg; IQR: 500 mg). Milligram/kilogram values were available for 103 (15.4%) with median 42.4 mg/kg, IQR: 39 mg/kg. Most (647, 98.5%) exposures were unintentional. Most (445/669, 66.5%) were managed at a non-healthcare facility, while 204 (30.7%) were already at or referred to a healthcare facility. Of these 204 patients, 169 (82.8%) were evaluated and treated at the emergency department and discharged. Four (2%) were admitted to critical care, and 7 (3.4%) to the ward. Medical outcomes by effect were 5 (0.7%) minor, 2 (0.3%) moderate, 253 (37.8%) none, 292 (43.6%) not followed (minimal effects possible), and no major effects or deaths. Of 20 clinical occurrences reported, vomiting was most common (8, 1.2%). Conclusion: Despite little recorded dosage information, pediatric metformin ingestions under 85 mg/kg had predominantly uneventful medical outcomes.

Detailed overview of incidence and management of cytokine release syndrome observed with teclistamab in the MajesTEC-1 study of patients with relapsed/refractory multiple myeloma.

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.

Cytomegalovirus seropositivity is associated with improved responses to CD38 monoclonal antibody therapies in multiple myeloma: A single-centre retrospective study.

The CD38-targeting monoclonal antibodies (CD38 mAbs) are well-established therapies in multiple myeloma (MM), but responses to treatment are not always deep or durable. Natural killer (NK) cells deficient in Fc epsilon receptor gamma subunits, known as g-NK cells, are found in higher numbers among individuals exposed to cytomegalovirus (CMV) and are able to potentiate the efficacy of daratumumab in vivo. Here, we present a single-centre, retrospective analysis of 136 patients with MM with known CMV serostatus who received a regimen containing a CD38 mAb (93.4% daratumumab and 6.6% isatuximab). CMV seropositivity was associated with an increased overall response rate to treatment regimens containing a CD38 mAb (odds ratio 2.65, 95% confidence interval [CI] 1.17-6.02). However, CMV serostatus was associated with shorter time to treatment failure in a multivariate Cox model (7.8 vs. 8.8 months in the CMV-seropositive vs. CMV-seronegative groups respectively, log-rank p = 0.18, hazard ratio 1.98, 95% CI 1.25-3.12). Our data suggest that CMV seropositivity may predict better response to CD38 mAbs, although this did not correspond to longer time to treatment failure. Larger studies directly quantitating g-NK cells are required to fully understand their effect on CD38 mAb efficacy in MM.

Utility of the burmese Python as a model for studying plasticity of extreme physiological systems.

Non-traditional animal models present an opportunity to discover novel biology that has evolved to allow such animals to survive in extreme environments. One striking example is the Burmese python (Python molurus bivittatus), which exhibits extreme physiological adaptation in various metabolic organs after consuming a large meal following long periods of fasting. The response to such a large meal in pythons involves a dramatic surge in metabolic rate, lipid overload in plasma, and massive but reversible organ growth through the course of digestion. Multiple studies have reported the physiological responses in post-prandial pythons, while the specific molecular control of these processes is less well-studied. Investigating the mechanisms that coordinate organ growth and adaptive responses offers the opportunity to gain novel insight that may be able to treat various pathologies in humans. Here, we summarize past research on the post-prandial physiological changes in the Burmese python with a focus on the gastrointestinal tract, heart, and liver. Specifically, we address our recent molecular discoveries in the post-prandial python liver which demonstrate transient adaptations that may reveal new therapeutic targets. Lastly, we explore new biology of the aquaporin 7 gene that is potently upregulated in mammalian cardiac myocytes by circulating factors in post-prandial python plasma.

Cilta-cel, a BCMA-targeting CAR-T therapy for heavily pretreated patients with relapsed/refractory multiple myeloma.

Cilta-cel, a BCMA-targeting chimeric antigen receptor T-cell therapy for multiple myeloma, was approved in USA on 28 February 2022, for patients with relapsed or refractory disease who have received ≥4 prior lines of therapy, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody. Approval in the EU followed for patients with ≥3 prior therapies. At median 28-month follow-up, the pivotal CARTITUDE-1 trial showed a 98% response rate (83% stringent complete response); median progression-free survival had not been reached, and adverse events could be managed with supportive therapy. Cilta-cel efficacy and safety in earlier lines of therapy, and its optimal sequencing in a complex treatment landscape are important areas of investigation.

Pharmacological inhibition of BAG3-HSP70 with the proposed cancer therapeutic JG-98 is toxic for cardiomyocytes.

The co-chaperone Bcl2-associated athanogene-3 (BAG3) maintains cellular protein quality control through the regulation of heat shock protein 70 (HSP70). Cancer cells manipulate BAG3-HSP70-regulated pathways for tumor initiation and proliferation, which has led to the development of promising small molecule therapies, such as JG-98, which inhibit the BAG3-HSP70 interaction and mitigate tumor growth. However, it is not known how these broad therapies impact cardiomyocytes, where the BAG3-HSP70 complex is a key regulator of protein turnover and contractility. Here, we show that JG-98 exposure is toxic in neonatal rat ventricular myocytes (NRVMs). Using immunofluorescence microscopy to assess cell death, we found that apoptosis increased in NRVMs treated with JG-98 doses as low as 10 nM. JG-98 treatment also reduced autophagy flux and altered expression of BAG3 and several binding partners involved in BAG3-dependent autophagy, including SYNPO2 and HSPB8. We next assessed protein half-life with disruption of the BAG3-HSP70 complex by treating with JG-98 in the presence of cycloheximide and found BAG3, HSPB5, and HSPB8 half-lives were reduced, indicating that complex formation with HSP70 is important for their stability. Next, we assessed sarcomere structure using super-resolution microscopy and found that disrupting the interaction with HSP70 leads to sarcomere structural disintegration. To determine whether the effects of JG-98 could be mitigated by pharmacological autophagy induction, we cotreated NRVMs with rapamycin, which partially reduced the extent of apoptosis and sarcomere disarray. Finally, we investigated whether the effects of JG-98 extended to skeletal myocytes using C2C12 myotubes and found again increased apoptosis and reduced autophagic flux. Together, our data suggest that nonspecific targeting of the BAG3-HSP70 complex to treat cancer may be detrimental for cardiac and skeletal myocytes.

Antibody and T-cell responses by ultra-deep T-cell receptor immunosequencing after COVID-19 vaccination in patients with plasma cell dyscrasias.

We investigated antibody and coronavirus disease 2019 (COVID-19)-specific T-cell mediated responses via ultra-deep immunosequencing of the T-cell receptor (TCR) repertoire in patients with plasma cell dyscrasias (PCD). We identified 364 patients with PCD who underwent spike antibody testing using commercially available spike-receptor binding domain immunoglobulin G antibodies ≥2 weeks after completion of the initial two doses of mRNA vaccines or one dose of JNJ-78436735. A total of 56 patients underwent TCR immunosequencing after vaccination. Overall, 86% tested within 6 months of vaccination had detectable spike antibodies. Increasing age, use of anti-CD38 or anti-B-cell maturation antigen therapy, and receipt of BNT162b2 (vs. mRNA-1273) were associated with lower antibody titres. We observed an increased proportion of TCRs associated with surface glycoprotein regions of the COVID-19 genome after vaccination, consistent with spike-specific T-cell responses. The median spike-specific T-cell breadth was 3.11 × 10-5 , comparable to those in healthy populations after vaccination. Although spike-specific T-cell breadth correlated with antibody titres, patients without antibody responses also demonstrated spike-specific T-cell responses. Patients receiving mRNA-1273 had higher median spike-specific T-cell breadth than those receiving BNT162b2 (p = 0.01). Although patients with PCD are often immunocompromised due to underlying disease and treatments, COVID-19 vaccination can still elicit humoral and T-cell responses and remain an important intervention in this patient population.

Isatuximab plus carfilzomib and dexamethasone versus carfilzomib and dexamethasone in elderly patients with relapsed multiple myeloma: IKEMA subgroup analysis.

In this subgroup analysis of the randomized, Phase 3 IKEMA study (NCT03275285), we evaluated efficacy and safety of the anti-CD38 monoclonal antibody isatuximab (Isa) in combination with carfilzomib-dexamethasone (Isa-Kd) versus Kd in older (≥70 years of age, n = 86) and younger (<70 years, n = 216) patients with relapsed multiple myeloma (MM). Patients received Isa 10 mg/kg intravenously weekly for 4 weeks, then every 2 weeks in the Isa-Kd arm, and approved schedule of carfilzomib (twice weekly) and dexamethasone in both study arms. Primary endpoint was progression-free survival (PFS); key secondary efficacy endpoints included rates of overall response (ORR), very good partial response or better (≥VGPR), minimal residual disease negativity (MRD-), and complete response (CR). Addition of Isa to Kd resulted in improved PFS in elderly patients (hazard ratio, 0.36 [95% CI, 0.18-0.75]) consistent with the significant PFS improvement observed in the overall IKEMA population. Treatment with Isa-Kd improved depth of response versus Kd, with higher rates of ≥VGPR (73.1% vs. 55.9%), MRD- (23.1% vs. 11.8%), and CR (38.5% vs. 23.5%). Although the incidence of grade ≥3 treatment-emergent adverse events (TEAEs) was higher in Isa-Kd, the incidence of serious TEAEs was similar between arms. Fewer elderly patients definitively discontinued treatment due to TEAEs in Isa-Kd than Kd: 11.8% versus 23.5%. In conclusion, Isa-Kd provides a consistent benefit versus Kd in elderly patients, with a manageable safety profile, and represents a new treatment option for patients with relapsed MM, independent of age.

Isatuximab plus carfilzomib and dexamethasone in relapsed multiple myeloma patients with high-risk cytogenetics: IKEMA subgroup analysis.

INTRODUCTION: The presence of high-risk chromosomal abnormalities [t(4;14), del(17p), and t(14;16)] has been linked with inferior outcomes in patients with multiple myeloma (MM). A prespecified interim analysis of the Phase 3 IKEMA study (NCT03275285) demonstrated that isatuximab (Isa) + carfilzomib (K) and dexamethasone (d; Isa-Kd) significantly improved progression-free survival (PFS) versus Kd in patients with relapsed MM. This prespecified subgroup analysis of IKEMA examined efficacy and safety in patients with high-risk cytogenetics. METHODS: High-risk cytogenetics was assessed by central laboratory and patients were classified as high risk if abnormalities were present in ≥1 of the following: del(17p): 50% cutoff; t(4;14), and/or t(14;16): 30% cutoff. RESULTS: Of the randomized patients, 23.5% (Isa-Kd) and 25.2% (Kd) had ≥1 high-risk chromosomal abnormality. A PFS benefit was seen in favor of Isa-Kd for patients with standard-risk (HR 0.440; 95% CI 0.266-0.728) and high-risk cytogenetics (HR 0.724; 95% CI 0.361-1.451). Grade ≥3 treatment-emergent adverse events (TEAEs) were more common with Isa-Kd (85.7%) versus Kd (63.3%) in patients with high-risk cytogenetics; however, the incidence of serious TEAEs (64.3% vs. 66.7%) was similar. CONCLUSIONS: Isa-Kd is a new treatment option for the difficult-to-treat subgroup of patients with relapsed MM and high-risk cytogenetics.

Outcomes of kidney transplant recipients with ESKD due to plasma cell dyscrasia: A case series.

Transplant centers have historically been reluctant to proceed with kidney transplantation in individuals with plasma cell dyscrasias (PCDs) due to concern for high rates of PCD recurrence and PCD-related mortality. As novel therapies for PCDs have improved hematologic outcomes, strategies to optimize kidney transplantation in individuals with PCD-mediated kidney disease are needed. In this single-center case series we discuss our protocol for the transplantation of individuals with ESKD attributed to PCD as well as the hematologic and allograft outcomes of 12 kidney transplant recipients with ESKD attributed to PCD. Median follow-up time after kidney transplantation was 44 months (IQR 36, 84). All patients had a functioning allograft 1 year after kidney transplantation. 9/12 patients were alive and had a functioning allograft 5 years after kidney transplantation. Five patients experienced relapse of PCD (of whom three responded well to subsequent therapies) and four patients developed secondary malignancies, including three patients with urologic malignancies. This case series demonstrates that patients with kidney disease attributed to PCD have favorable outcomes with kidney transplantation. Transplant evaluation in patients with PCDs should involve a multidisciplinary team of transplant nephrologists and oncologists to select appropriate candidates. Providers should consider screening for urologic malignancies pre- and post-transplantation.

Evaluation of subcutaneous daratumumab injections in the ambulatory care setting.

INTRODUCTION: Subcutaneous daratumumab is non-inferior to intravenous daratumumab for the treatment of multiple myeloma and significantly reduced incidence of systemic reactions. However, manufacturer for subcutaneous daratumumab has not provided guidance regarding optimal methods for monitoring for hypersensitivity reactions following subcutaneous daratumumab administration. METHODS: A retrospective analysis was performed in two cohorts of patients who received at least two doses of subcutaneous daratumumab for the treatment of plasma cell disorders: patients with previous exposure to intravenous daratumumab (dara-exposed) and patients without history of intravenous daratumumab (dara-naïve). The primary outcome was incidence of systemic and injection-site reactions following first dose of subcutaneous daratumumab. Secondary analysis included time to systemic and injection-site reactions, grading of adverse reaction, and incidence of second systemic reaction. RESULTS: Thirty-one patients were dara-naïve and 49 patients were dara-exposed. Differences in incidence of systemic (dara-naïve: 9.7% vs dara-exposed: 6.1%, p = 0.67) and injection-site reactions (dara-naïve: 12.9% vs dara-exposed: 14.3%, p = 0.99) did not reach statistical significance. Difference in median time to systemic reaction (dara-naïve: 3 h vs dara-exposed: 12 h, p = 0.18) was clinically important but did not reach statistical significance. Median time to injection-site reactions (dara-naïve: 6 h vs dara-exposed: 24 h, p = 0.03) was shorter in the dara-naïve cohort. No clinically meaningful difference was observed for incidence of second systemic reaction. CONCLUSION: Most reactions were mild and did not require medical intervention. Following first subcutaneous daratumumab dose, monitoring for 3 h for dara-naïve patients and no monitoring time for dara-exposed patients for hypersensitivity reactions may be a safe and reasonable practice.

Phase 1b trial of isatuximab, an anti-CD38 monoclonal antibody, in combination with carfilzomib as treatment of relapsed/refractory multiple myeloma.

BACKGROUND: Isatuximab (Isa), an anti-CD38 monoclonal antibody, and carfilzomib (K), a next-generation proteasome inhibitor (PI), both have potent single-agent activity in relapsed and refractory multiple myeloma (RRMM). METHODS: This phase 1b study evaluated the combination of Isa and K in 33 patients with RRMM. Isa was administered by intravenous infusion in 3 dosing cohorts: dose level 1 (Isa at 10 mg/kg biweekly), dose level 2 (DL2; Isa at 10 mg/kg weekly for 4 doses and then biweekly), and dose level 3 (Isa at 20 mg/kg weekly for 4 doses and then biweekly) and all patients received K (20 mg/m2 intravenously for cycle 1, days 1 and 2, and then 27 mg/m2 for all subsequent doses). A standard 3+3 dose-escalation design was used, no dose-limiting toxicity was observed, and the maximum tolerated dose was not reached. An expansion cohort of 18 patients was enrolled at DL2 to further evaluate safety and efficacy. Responses were assessed with the International Myeloma Working Group response criteria, and patients continued treatment until disease progression or unacceptable toxicity. RESULTS: With a median follow-up of 26.7 months, in this heavily pretreated population with a median of 3 prior lines (refractory to PIs and immunomodulatory drugs, 76%; refractory to K, 27%), the overall response rate was 70% (stringent complete response/complete response, 4; very good partial response, 8; partial response, 11). The median progression-free survival was 10.1 months, and the 2-year survival probability was 76%. The most common treatment-related adverse events (grade 2 or higher) were anemia, leukopenia, neutropenia, thrombocytopenia, hypertension, and infection. Infusion reactions were common (55%) but did not limit dosing. CONCLUSIONS: Treatment with Isa plus K was well tolerated with no unexpected toxicity. The combination was effective despite the enrollment of heavily pretreated patients with RRMM. LAY SUMMARY: This phase 1b study was designed to assess the safety, pharmacokinetics, and preliminary efficacy of isatuximab and carfilzomib in patients with relapsed and refractory multiple myeloma. Thirty-three patients were treated: 15 in dose escalation and 18 in dose expansion. Patients received an average of 10 cycles. The treatment was safe and effective. No unexpected toxicity or drug-drug interactions were noted. Seventy percent of the subjects responded to therapy, and the progression-free survival was 10.1 months.

BAG3 expression and sarcomere localization in the human heart are linked to HSF-1 and are differentially affected by sex and disease.

Mutations to the sarcomere-localized cochaperone protein Bcl2-associated athanogene 3 (BAG3) are associated with dilated cardiomyopathy (DCM) and display greater penetrance in male patients. Decreased protein expression of BAG3 is also associated with nongenetic heart failure; however, the factors regulating cardiac BAG3 expression are unknown. Using left ventricular (LV) tissue from nonfailing and DCM human samples, we found that whole LV BAG3 expression was not significantly impacted by DCM or sex; however, myofilament localized BAG3 was significantly decreased in males with DCM. Females with DCM displayed no changes in BAG3 compared with nonfailing. This sex difference appears to be estrogen independent, as estrogen treatment in ovariectomized female rats had no impact on BAG3 expression. BAG3 gene expression in noncardiac cells is primarily regulated by the heat shock transcription factor-1 (HSF-1). We show whole LV HSF-1 expression and nuclear localized/active HSF-1 each displayed a striking positive correlation with whole LV BAG3 expression. We further found that HSF-1 localizes to the sarcomere Z-disc in cardiomyocytes and that this myofilament-associated HSF-1 pool decreases in heart failure. The decrease of HSF-1 was more pronounced in male patients and tightly correlated with myofilament BAG3 expression. Together our findings indicate that cardiac BAG3 expression and myofilament localization are differentially impacted by sex and disease and are linked to HSF-1.NEW & NOTEWORTHY Myofilament BAG3 expression decreases in male patients with nonischemic DCM but is preserved in female patients with DCM. BAG3 expression in the human heart is tightly linked to HSF-1 expression and nuclear translocation. HSF-1 localizes to the sarcomere Z-disc in the human heart. HSF-1 expression in the myofilament fraction decreases in male patients with DCM and positively correlates with myofilament BAG3.

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

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

Lay abstract For patients with multiple myeloma, navigating cancer relapses can be difficult. The combination of isatuximab, carfilzomib and dexamethasone (Isa-Kd), which was studied in the large ongoing IKEMA study, has recently been approved by government authorities in both the USA and Europe for treating multiple myeloma that has relapsed after initial therapy. Isatuximab is a drug that attacks the CD38 protein on myeloma cancer cells, while carfilzomib is a drug that prevents myeloma cancer cells from properly using and reusing proteins. Dexamethasone is a corticosteroid that has been shown to improve how well other antimyeloma drugs work. In this review, we discuss potential strengths and weaknesses of the Isa-Kd combination for patients with multiple myeloma that has relapsed.

Under construction: The dynamic assembly, maintenance, and degradation of the cardiac sarcomere.

The sarcomere is the basic contractile unit of striated muscle and is a highly ordered protein complex with the actin and myosin filaments at its core. Assembling the sarcomere constituents into this organized structure in development, and with muscle growth as new sarcomeres are built, is a complex process coordinated by numerous factors. Once assembled, the sarcomere requires constant maintenance as its continuous contraction is accompanied by elevated mechanical, thermal, and oxidative stress, which predispose proteins to misfolding and toxic aggregation. To prevent protein misfolding and maintain sarcomere integrity, the sarcomere is monitored by an assortment of protein quality control (PQC) mechanisms. The need for effective PQC is heightened in cardiomyocytes which are terminally differentiated and must survive for many years while preserving optimal mechanical output. To prevent toxic protein aggregation, molecular chaperones stabilize denatured sarcomere proteins and promote their refolding. However, when old and misfolded proteins cannot be salvaged by chaperones, they must be recycled via degradation pathways: the calpain and ubiquitin-proteasome systems, which operate under basal conditions, and the stress-responsive autophagy-lysosome pathway. Mutations to and deficiency of the molecular chaperones and associated factors charged with sarcomere maintenance commonly lead to sarcomere structural disarray and the progression of heart disease, highlighting the necessity of effective sarcomere PQC for maintaining cardiac function. This review focuses on the dynamic regulation of assembly and turnover at the sarcomere with an emphasis on the chaperones involved in these processes and describes the alterations to chaperones - through mutations and deficient expression - implicated in disease progression to heart failure.

Impact of Plerixafor Use at Different Peripheral Blood CD34+ Thresholds on Autologous Stem Cell Collection in Patients with Multiple Myeloma.

Patients with multiple myeloma (MM) scheduled for autologous stem cell transplantation must undergo autologous stem cell mobilization; unfortunately, however, many do not obtain an adequate collection yield. Despite the availability of plerixafor, its widespread and uniform use is limited by its cost, and consequently, many institutions have adopted various risk-adapted algorithms. We report our mobilization experience as we have modified our plerixafor algorithm to a more liberal one, with the expectation of greater collection efficiency and mobilization success with higher plerixafor use. A total of 344 mobilization attempts were analyzed over 3 time periods and using 3 different peripheral blood CD34+ cell counts to guide plerixafor use: <15/µL (n = 66), <20/µL (n = 130), and <40/µL (n = 148). The primary endpoints were evaluation of changes in mean plerixafor utilization and apheresis days and assessment of the impact on overall mobilization costs. Secondary endpoints were a description of the impact of lenalidomide use on mobilization and evaluation of the rate of mobilization failure. We found that mean plerixafor use increased from 1.32 to 1.65 to 1.74 doses per mobilization (P = .026) and the mean days of apheresis decreased from 2.15 to 2.17 to 1.89 days per mobilization for the <15/µL, <20/µL, and <40/µL cohorts, respectively (P = .011). The combined cost of plerixafor and apheresis procedures at a threshold of 40/µL is close to that at a threshold of 15/µL, while saving 26 apheresis days per 100 patients. In general, there were low rates of mobilization failure across all thresholds. Patients who received more than 6 cycles of lenalidomide demonstrated impaired mobilization and required more apheresis sessions (P < .013) and greater plerixafor use (P < .001) to achieve target stem cell yields. Overall, using plerixafor in patients with MM, with a day 4 pCD34 count of <40/µL is a reasonable and cost-effective strategy to optimize apheresis utilization.