Hearts apart: sex differences in cardiac remodeling in health and disease.

Biological sex is an important modifier of physiology and influences pathobiology in many diseases. While heart disease is the number one cause of death worldwide in both men and women, sex differences exist at the organ and cellular scales, affecting clinical presentation, diagnosis, and treatment. In this Review, we highlight baseline sex differences in cardiac structure, function, and cellular signaling and discuss the contribution of sex hormones and chromosomes to these characteristics. The heart is a remarkably plastic organ and rapidly responds to physiological and pathological cues by modifying form and function. The nature and extent of cardiac remodeling in response to these stimuli are often dependent on biological sex. We discuss organ- and molecular-level sex differences in adaptive physiological remodeling and pathological cardiac remodeling from pressure and volume overload, ischemia, and genetic heart disease. Finally, we offer a perspective on key future directions for research into cardiac sex differences.

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.

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.).

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.

CD4+ CAR-T cell exhaustion associated with early relapse of multiple myeloma after BCMA CAR-T cell therapy.

Multiple myeloma is characterized by frequent clinical relapses following conventional therapy. Recently, chimeric antigen receptor T (CAR-T) cells targeting B-cell maturation antigen (BCMA) has been established as a treatment option for patients with relapsed or refractory disease. However, while >70% of patients initially respond to this treatment, clinical relapse and disease progression occur in most cases. Recent studies showed persistent expression of BCMA at the time of relapse, indicating that immune intrinsic mechanisms may contribute to this resistance. While there were no pre-existing T cell features associated with clinical outcomes, we found that patients with a durable response to CAR-T cell treatment had greater persistence of their CAR-T cells compared to patients with transient clinical responses. They also possessed a significantly higher proportion of CD8+ T effector memory cells. In contrast, patients with short-lived responses to treatment have increased frequencies of cytotoxic CD4+ CAR-T cells. These cells expand in vivo early after infusion but express exhaustion markers (HAVCR2 and TIGIT) and remain polyclonal. Finally, we demonstrate that non-classical monocytes are enriched in the myeloma niche and may induce CAR-T cell dysfunction through mechanisms that include TGFß. These findings shed new light on the role of cytotoxic CD4+ T cells in disease progression after CAR-T cell therapy.

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.

A Conserved Mechanism of Cardiac Hypertrophy Regression through FoxO1.

The heart is a highly plastic organ that responds to diverse stimuli to modify form and function. The molecular mechanisms of adaptive physiological cardiac hypertrophy are well-established; however, the regulation of hypertrophy regression is poorly understood. To identify molecular features of regression, we studied Burmese pythons which experience reversible cardiac hypertrophy following large, infrequent meals. Using multi-omics screens followed by targeted analyses, we found forkhead box protein O1 (FoxO1) transcription factor signaling, and downstream autophagy activity, were downregulated during hypertrophy, but re-activated with regression. To determine whether these events were mechanistically related to regression, we established an in vitro platform of cardiomyocyte hypertrophy and regression from treatment with fed python plasma. FoxO1 inhibition prevented regression in this system, while FoxO1 activation reversed fed python plasma-induced hypertrophy in an autophagy-dependent manner. We next examined whether FoxO1 was implicated in mammalian models of reversible hypertrophy from exercise and pregnancy and found that in both cases FoxO1 was activated during regression. In these models, as in pythons, activation of FoxO1 was associated with increased expression FoxO1 target genes involved in autophagy. Taken together, our findings suggest FoxO1-dependent autophagy is a conserved mechanism for regression of physiological cardiac hypertrophy across species.

Teclistamab impairs humoral immunity in patients with heavily pretreated myeloma: importance of immunoglobulin supplementation.

ABSTRACT: Teclistamab and other B-cell maturation antigen (BCMA)-targeting bispecific antibodies (BsAbs) have substantial activity in patients with heavily pretreated multiple myeloma (MM) but are associated with a high rate of infections. BCMA is also expressed on normal plasma cells and mature B cells, which are essential for the generation of a humoral immune response. The aim of this study was to improve the understanding of the impact of BCMA-targeting BsAbs on humoral immunity. The impact of teclistamab on polyclonal immunoglobulins and B cell counts was evaluated in patients with MM who received once-weekly teclistamab 1.5 mg/kg subcutaneously. Vaccination responses were assessed in a subset of patients. Teclistamabinduced rapid depletion of peripheral blood B cells in patients with MM and eliminated normal plasma cells in ex vivo assays. In addition, teclistamab reduced the levels of polyclonal immunoglobulins (immunoglobulin G [IgG], IgA, IgE, and IgM), without recovery over time while receiving teclistamab therapy. Furthermore, response to vaccines against Streptococcus pneumoniae, Haemophilus influenzae type B, and severe acute respiratory syndrome coronavirus 2 was severely impaired in patients treated with teclistamab compared with vaccination responses observed in patients with newly diagnosed MM or relapsed/refractory MM. Intravenous immunoglobulin (IVIG) use was associated with a significantly lower risk of serious infections among patients treated with teclistamab (cumulative incidence of infections at 6 months: 5.3% with IVIG vs 54.8% with observation only [P < .001]). In conclusion, our data show severe defects in humoral immunity induced by teclistamab, the impact of which can be mitigated by the use of immunoglobulin supplementation. This trial was registered at www.ClinicalTrials.gov as #NCT04557098.

Teclistamab Improves Patient-Reported Symptoms and Health-Related Quality of Life in Relapsed or Refractory Multiple Myeloma: Results From the Phase II MajesTEC-1 Study.

INTRODUCTION: Patients with relapsed or refractory multiple myeloma (RRMM) report significantly lower HRQoL compared with patients with newly diagnosed MM and experience further deterioration in HRQoL with each relapse and subsequent treatment. Therefore, consideration of the impact of treatment on HRQoL in addition to clinical outcomes is vital. PATIENTS AND METHODS: In the phase I/II MajesTEC-1 (NCT03145181, NCT04557098) study, patients with RRMM who received teclistamab, an off-the-shelf, T-cell redirecting BCMA × CD3 bispecific antibody, had deep and durable responses with manageable safety. HRQoL was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire core 30-item and the EuroQol 5 Dimension 5 Level descriptive questionnaire. Changes over time from baseline were measured with a repeated measures mixed-effects model. Proportions of patients with clinically meaningful improvement after starting treatment and time to clinically meaningful worsening were assessed. RESULTS: Compliance was maintained throughout the study. Compared with baseline, positive changes were observed for pain, global health status, and emotional functioning with treatment; other assessments were largely unchanged from baseline. Post hoc analysis showed patients with deeper clinical response generally reported improved HRQoL outcomes. Following an initial decline in HRQoL in some scales, the proportion of patients reporting clinically meaningful improvements increased, while the proportion reporting clinically meaningful worsening decreased over time. Clinically meaningful improvements in pain were reported in ≥40% of patients at most assessment time points. CONCLUSIONS: These results complement previously reported clinical benefits and support teclistamab as a promising therapeutic option for patients with RRMM.

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.

CD46-Targeted Theranostics for PET and 225Ac-Radiopharmaceutical Therapy of Multiple Myeloma.

PURPOSE: Multiple myeloma is a plasma cell malignancy with an unmet clinical need for improved imaging methods and therapeutics. Recently, we identified CD46 as an overexpressed therapeutic target in multiple myeloma and developed the antibody YS5, which targets a cancer-specific epitope on this protein. We further developed the CD46-targeting PET probe [89Zr]Zr-DFO-YS5 for imaging and [225Ac]Ac-DOTA-YS5 for radiopharmaceutical therapy of prostate cancer. These prior studies suggested the feasibility of the CD46 antigen as a theranostic target in multiple myeloma. Herein, we validate [89Zr]Zr-DFO-YS5 for immunoPET imaging and [225Ac]Ac-DOTA-YS5 for radiopharmaceutical therapy of multiple myeloma in murine models. EXPERIMENTAL DESIGN: In vitro saturation binding was performed using the CD46 expressing MM.1S multiple myeloma cell line. ImmunoPET imaging using [89Zr]Zr-DFO-YS5 was performed in immunodeficient (NSG) mice bearing subcutaneous and systemic multiple myeloma xenografts. For radioligand therapy, [225Ac]Ac-DOTA-YS5 was prepared, and both dose escalation and fractionated dose treatment studies were performed in mice bearing MM1.S-Luc systemic xenografts. Tumor burden was analyzed using BLI, and body weight and overall survival were recorded to assess antitumor effect and toxicity. RESULTS: [89Zr]Zr-DFO-YS5 demonstrated high affinity for CD46 expressing MM.1S multiple myeloma cells (Kd = 16.3 nmol/L). In vitro assays in multiple myeloma cell lines demonstrated high binding, and bioinformatics analysis of human multiple myeloma samples revealed high CD46 expression. [89Zr]Zr-DFO-YS5 PET/CT specifically detected multiple myeloma lesions in a variety of models, with low uptake in controls, including CD46 knockout (KO) mice or multiple myeloma mice using a nontargeted antibody. In the MM.1S systemic model, localization of uptake on PET imaging correlated well with the luciferase expression from tumor cells. A treatment study using [225Ac]Ac-DOTA-YS5 in the MM.1S systemic model demonstrated a clear tumor volume and survival benefit in the treated groups. CONCLUSIONS: Our study showed that the CD46-targeted probe [89Zr]Zr-DFO-YS5 can successfully image CD46-expressing multiple myeloma xenografts in murine models, and [225Ac]Ac-DOTA-YS5 can effectively inhibit the growth of multiple myeloma. These results demonstrate that CD46 is a promising theranostic target for multiple myeloma, with the potential for clinical translation.

Dysregulated Autophagy and Sarcomere Dysfunction in Patients With Heart Failure With Co-Occurrence of P63A and P380S BAG3 Variants.

BACKGROUND: Mutations to the co-chaperone protein BAG3 (B-cell lymphoma-2-associated athanogene-3) are a leading cause of dilated cardiomyopathy (DCM). These mutations often impact the C-terminal BAG domain (residues 420-499), which regulates heat shock protein 70-dependent protein turnover via autophagy. While mutations in other regions are less common, previous studies in patients with DCM found that co-occurrence of 2 BAG3 variants (P63A, P380S) led to worse prognosis. However, the underlying mechanism for dysfunction is not fully understood. METHODS AND RESULTS: In this study, we used proteomics, Western blots, and myofilament functional assays on left ventricular tissue from patients with nonfailing, DCM, and DCM with BAG363/380 to determine how these mutations impact protein quality control and cardiomyocyte contractile function. We found dysregulated autophagy and increased protein ubiquitination in patients with BAG363/380 compared with nonfailing and DCM, suggesting impaired protein turnover. Expression and myofilament localization of BAG3-binding proteins were also uniquely altered in the BAG3,63/380 including abolished localization of the small heat shock protein CRYAB (alpha-crystallin B chain) to the sarcomere. To determine whether these variants impacted sarcomere function, we used cardiomyocyte force-calcium assays and found reduced maximal calcium-activated force in DCM and BAG363/380. Interestingly, myofilament calcium sensitivity was increased in DCM but not with BAG363/380, which was not explained by differences in troponin I phosphorylation. CONCLUSIONS: Together, our data support that the disease-enhancing mechanism for BAG3 variants outside of the BAG domain is through disrupted protein turnover leading to compromised sarcomere function. These findings suggest a shared mechanism of disease among pathogenic BAG3 variants, regardless of location.

Assessment of Autophagy Markers Suggests Increased Activity Following LVAD Therapy.

Left ventricular reverse remodeling in heart failure is associated with improved clinical outcomes. However, the molecular features that drive this process are poorly defined. Left ventricular assist devices (LVADs) are the therapy associated with the greatest reverse remodeling and lead to partial myocardial recovery in most patients. In this study, we examined whether autophagy may be implicated in post-LVAD reverse remodeling. We found expression of key autophagy factors increased post-LVAD, while autophagic substrates decreased. Autolysosome numbers increased post-LVAD, further indicating increased autophagy. These findings support the conclusion that mechanical unloading activates autophagy, which may underly the reverse remodeling observed.

Association of geriatric measures and global frailty with cognitive decline after allogeneic hematopoietic cell transplantation in older adults.

INTRODUCTION: Allogeneic hematopoietic cell transplantation (alloHCT) is increasingly offered to older adults, and its potential impact on cognition in this population is understudied. This work aims to evaluate the ability of cancer-specific geriatric assessments (cGA) and a global frailty index based on accumulation of deficits identified in the cGA to predict the risk of cognitive decline after alloHCT in older adults. MATERIALS AND METHODS: AlloHCT recipients aged 50 years or older completed a cGA, including a cognitive evaluation by the Blessed Orientation Memory Concentration (BOMC) test, at baseline prior to alloHCT and then at 3, 6, and 12 months after transplant. Baseline frailty was assessed using a deficit accumulation frailty index (DAFI) calculated from the cGA. A multinomial logit model was used to examine the association between predictors (individual cGA measures, DAFI) and the following three outcomes: alive with stable or improved cognition, alive with cognitive decline, and deceased. In post-hoc analyses, analysis of variance was used to compare BOMC scores at baseline, 3, 6, and 12 months across frailty categories. RESULTS: In total, 148 participants were included, with a median age of 62 (range 50-76). At baseline, 12% had cognitive impairment; at one year, 29% of survivors had improved BOMC scores, 33% had stable BOMC, and 37% had worse BOMC. Prior to transplant, 25% were pre-frail and 11% were frail. Individual baseline cGA measures were not associated with cognitive change at one year as assessed by BOMC. Adjusting for age, sex, and education, those who were frail at baseline were 7.4 times as likely to develop cognitive decline at one year than those who were non-frail, although this finding did not reach statistical significance (95% confidence interval [CI] 0.74-73.8, p = 0.09). The probability of being alive with stable/improved cognition at 12 months for the non-frail, pre-frail, and frail groups was 43%, 34%, and 8%, respectively. DISCUSSION: Baseline geriatric measures and frailty were not significantly associated with cognitive change as assessed by BOMC in adults aged 50 or older after alloHCT. However, the study was underpowered to detect clinically meaningful differences, and future work to elucidate potential associations between frailty and cognitive outcomes is warranted.

Peptidyl arginine deiminase inhibition alleviates angiotensin II-induced fibrosis.

OBJECTIVES: The conversion of protein arginine residues to citrulline by calcium-dependent peptidyl arginine deiminases (PADs) has been implicated in the pathogenesis of several diseases, indicating that PADs are therapeutic targets. A recent study indicated that PAD4 regulates age-related organ fibrosis and dysfunction; however, the specific role of this PAD and its citrullination substrate remains unclear. We investigated whether pharmacological inhibition of PAD activity could affect the progression of fibrosis and restore heart function. METHODS: Cardiac hypertrophy was induced by chronic infusion of angiotensin (Ang) II. After 2 weeks of AngII infusion, a PAD inhibitor (Cl-amidine hydrochloride) or vehicle (saline) was injected every other day for the next 14 days together with the continued administration of AngII for a total of up to 28 days. Cardiac fibrosis and remodeling were evaluated by quantitative heart tissue histology, echocardiography, and mass spectrometry. RESULTS: A reverse AngII-induced effect was observed in PAD inhibitor-treated mice (n=6) compared with AngII vehicle-treated mice, as indicated by a significant reduction in the heart/body ratio (AngII: 6.51±0.8 mg/g vs. Cl-amidine: 5.27±0.6 mg/g), a reduction in fibrosis (AngII: 2.1-fold increased vs. Cl-amidine: 1.8-fold increased), and a reduction in left ventricular posterior wall diastole (LWVPd) (AngII: 1.1±0.04 vs. Cl-amidine: 0.78±0.02 mm). Label-free quantitative proteomics analysis of heart tissue indicated that proteins involved in fibrosis (e.g., periostin), cytoskeleton organization (e.g., transgelin), and remodeling (e.g., myosin light chain, carbonic anhydrase) were normalized by Cl-amidine treatment. CONCLUSION: Our findings demonstrate that pharmacological inhibition of PAD may be an effective strategy to attenuate cardiac fibrosis.

Bag3 Regulates Mitochondrial Function and the Inflammasome Through Canonical and Noncanonical Pathways in the Heart.

B-cell lymphoma 2-associated athanogene-3 (Bag3) is expressed in all animal species, with Bag3 levels being most prominent in the heart, the skeletal muscle, the central nervous system, and in many cancers. Preclinical studies of Bag3 biology have focused on animals that have developed compromised cardiac function; however, the present studies were performed to identify the pathways perturbed in the heart even before the occurrence of clinical signs of dilatation and failure of the heart. These studies show that hearts carrying variants that knockout one allele of BAG3 have significant alterations in multiple cellular pathways including apoptosis, autophagy, mitochondrial homeostasis, and the inflammasome.

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.

Extrapolation of Survival Data Using a Bayesian Approach: A Case Study Leveraging External Data from Cilta-Cel Therapy in Multiple Myeloma.

INTRODUCTION: Extrapolating long-term overall survival (OS) from shorter-term clinical trial data is key to health technology assessment in oncology. However, extrapolation using conventional methods is often subject to uncertainty. Using ciltacabtagene autoleucel (cilta-cel), a chimeric antigen receptor T-cell therapy for multiple myeloma, we used a flexible Bayesian approach to demonstrate use of external longer-term data to reduce the uncertainty in long-term extrapolation. METHODS: The pivotal CARTITUDE-1 trial (NCT03548207) provided the primary efficacy data for cilta-cel, including a 12-month median follow-up snapshot of OS. Longer-term (48-month median follow-up) survival data from the phase I LEGEND-2 study (NCT03090659) were also available. Twelve-month CARTITUDE-1 OS data were extrapolated in two ways: (1) conventional survival models with standard parametric distributions (uninformed), and (2) Bayesian survival models whose shape prior was informed from 48-month LEGEND-2 data. For validation, extrapolations from 12-month CARTITUDE-1 data were compared with observed 28-month CARTITUDE-1 data. RESULTS: Extrapolations of the 12-month CARTITUDE-1 data using conventional uninformed parametric models were highly variable. Using informative priors from the 48-month LEGEND-2 dataset, the ranges of projected OS at different timepoints were consistently narrower. Area differences between the extrapolation curves and the 28-month CARTITUDE-1 data were generally lower in informed Bayesian models, except for the uninformed log-normal model, which had the lowest difference. CONCLUSIONS: Informed Bayesian survival models reduced variation of long-term projections and provided similar projections as the uninformed log-normal model. Bayesian models generated a narrower and more plausible range of OS projections from 12-month data that aligned with observed 28-month data. TRIAL REGISTRATION: CARTITUDE-1 ClinicalTrials.gov identifier, NCT03548207. LEGEND-2 ClinicalTrials.gov identifier, NCT03090659, registered retrospectively on 27 March 2017, and ChiCTR-ONH-17012285.

Intensity of Cyclophosphamide-Based Bridging Therapy Before Chimeric Antigen Receptor T Cell Therapy in Myeloma.

Patients receiving autologous chimeric antigen receptor T cell (CAR-T) therapy for multiple myeloma (MM) may require bridging therapy (BT) before CAR-T infusion to maintain some level of disease control. Alkylators, such as cyclophosphamide (Cy), are often used in regimens, either in high-intensity regimens, such as modified hyperCVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone), or once-weekly regimens, such as KCd (carfilzomib, cyclophosphamide, and dexamethasone). However, there is no consensus regarding the optimal BT alkylator dose intensity in MM. We performed a single-center analysis of all instances of BT before planned autologous CAR-T for MM during a 5-year period ending in April 2022. We classified bridging regimens into 3 cohorts: (1) hyperfractionated Cy (HyperCy) with inpatient Cy every 12 to 24 hours or as a continuous i.v. infusion; (2) less intensive Cy dosing (WeeklyCy), such as KCd; and (3) NonCy, in which no alkylators were used in BT. Demographic, disease-related, and treatment-related characteristics were collected for all patients. The 3 BT cohorts were compared using the Fisher exact test, Kruskal-Wallis test, and log-rank test, as appropriate. We identified 70 discrete BT instances among 64 unique patients, including 29 (41%) with HyperCy, 23 (33%) with WeeklyCy, and 18 (26%) with NonCy. The median total Cy dosing during BT in the 3 groups were 2100 mg/m2, 615 mg/m2, and 0 mg/m2, respectively. Age, number of prior lines of therapy, triple-class refractory status, presence of high-risk cytogenetics, extramedullary disease, bone marrow plasma cell burden, involved free light chain (iFLC) kinetics before collection, and other measures of disease aggressiveness were comparable across the 3 cohorts. iFLC levels rose ≥25% and ≥100 mg/L during BT (approximating progressive disease) in comparable proportions (P = .25) among the cohorts: 52% for HyperCy, 39% for WeeklyCy, and 28% for NonCy. All BT instances without subsequent CAR-T were due to manufacturing failures. Among 61 instances of BT followed by CAR-T, vein-to-vein times were slightly longer (P = .03) with HyperCy (45 days) compared with WeeklyCy (39 days) and NonCy (46.5 days). Neutrophil recovery times were similar in the 3 cohorts, but platelet recovery took longer with HyperCy (64 days) compared with WeeklyCy (42 days) and NonCy (12 days). Progression-free survival was comparable among the cohorts, but median overall survival (OS) was not: 15.3 months with HyperCy, versus 30.0 months with WeeklyCy and not reached with NonCy. In our retrospective analysis of BT before CAR-T therapy in MM, HyperCy did not result in superior disease control than WeeklyCy despite a 3-fold higher dose of Cy. In contrast, HyperCy was associated with longer post-CAR-T platelet recovery and worse OS despite comparable measurements of disease aggressiveness and tumor burden. Study limitations include our small sample size, as well as confounding from gestalt markers of MM aggressiveness that might have led to poorer outcomes as well as physicians' decision to prescribe HyperCy. Given the rarity of objective disease responses to chemotherapy in relapsed/refractory MM, our analysis suggests that hyperfractionated Cy regimens do not outperform once-weekly Cy regimens for most patients who require BT before CAR-T therapy.