Background: Indications for TAVR explant have been established, although limited data exist regarding pre-TAVR baseline characteristics that predict eventual explantation. Methods: The TriNetX network, a database comprising medical records from over 105 institutions, was used. Two cohorts were created: those who underwent TAVR without explant and those requiring subsequent TAVR explant and SAVR. Predictors of explantation were analyzed by multivariate models. Results: Among the 63,377 patients undergoing TAVR, 273 (0.4%) required explantation. Patients in the explant group were younger (69.1 ± 11.3 vs. 78.1 ± 8.8 years; p < 0.001), more likely to have a thoracic aortic aneurysm (TAA) (10.6% vs. 4.7%; p < 0.001) and had higher LDL levels (88.2 ± 41.3 vs. 80.7 ± 34.6 mg/dL; p = 0.011). They also had increased post-TAVR rates of acute kidney injury (9.2% vs. 5.2%; p = 0.004) and paravalvular leak (5.9% vs. 0.9%; p < 0.001). Age at TAVR (HR 1.04; CI 1.03–1.06), baseline TAA (HR 1.69; CI 1.09–2.63), history of infective endocarditis (HR 1.92; CI 1.10–3.35), and higher LDL (HR 1.02; 95% CI 1.00–1.03) were independent predictors for explantation. Conclusions: Younger age at TAVR, TAA, history of endocarditis, and elevated baseline LDL were notable predictors of explantation. These findings highlight the necessity of pre-procedural assessment and follow-up in high-risk patients to optimize TAVR durability.
Intravenously administered LV-169 delivers a functional BCMA-CAR transgene to niche-resident T cells and leads to elimination of disseminated myeloma in MHC-deficient NSG mice
Abstract Chimeric Antigen Receptor (CAR) T cell therapy is a transformative treatment for hematologic malignancies. However, ex vivo autologous CAR T cell manufacturing presents substantial logistical and clinical challenges. Direct in vivo CAR-T cell engineering offers a new paradigm for CAR T delivery. We recently developed the CD3-targeted lentiviral vector LV-169 which can deliver a CAR transgene to resting niche-resident T cells in lymphoid tissues. LV169 is pseudotyped with a mix of chimeric and nonchimeric VSV-G proteins detargeted (blinded) from the natural LDL receptor and re-targeted to T cells through the display of a CD3-specific scFv. Here we demonstrate that LV169 can specifically deliver a functional aBCMA-CAR transgene to resting human T cells in PBMC cultures from the healthy volunteers and from multiple myeloma patients. For clinical translation, we selected an αBCMA-CAR construct comprising a fully human single heavy chain nanobody linked to 41BB and CD3z cytoplasmic signaling domains. Human T cells expressing this CAR construct have low tonic signaling and efficiently kill BCMA-positive myeloma target cells with similar or lower associated cytokine release compared to a clinically relevant benchmark BCMA-CAR. To further improve LV169 and to minimize CAR protein incorporation in the LV envelope which may lead undesirably to myeloma cell transduction, we placed the CAR transgene under a T-cell specific Lck promoter in reverse orientation relative to the 5' LTR. The transcriptional activity of the Lck promoter was comparable to that of a constitutive EF1a promoter in primary T cells and, in contrast to EF1a had minimal activity in a variety of other tested cell types including the HEK293T producer cell line and the THP-1 monocytic cell line. Western blotting confirmed the absence of CAR protein in LV particles (LVP) generated using the Lck promoter-driven reverse orientation construct. In contrast, high levels of CAR protein were detected in LVP generated using the parental EF1a promoter-driven construct. The LV-incorporated CAR protein mediated off-target gene delivery to BCMA-positive myeloma cells. The therapeutic efficacy of intravenously administered LV169 LV particles carrying BCMA-CAR constructs was tested in the OPM-2 human multiple myeloma xenograft model. NSG mice with knockout of MHC-I and MHC-II, and with advanced disseminated OPM-2-Luc tumors were engrafted with human PBMC one week prior to intravenous LV169-BCMA-CAR administration. Mice were treated with single intravenous injection of LV169 at different doses 3 weeks after tumor engraftment. OPM-2-Luc tumor burden was monitored by regular luciferase imaging. All treated mice cleared their tumors within 28-days following LV administration and the rate of clearance was correlated to the LV particle dose. Even at the 4e8 dose level (by p24) tumors were completely cleared. Eighty four days post-treatment the treated mice remained tumor-free and resisted re-challenge with OPM-2 tumor cells. Circulating CAR-T cells, monitored by flow cytometry, became detectable by 14 dpi and peaked between 21-35 dpi. Following tumor clearance, the number of circulating CAR-T cells declined dramatically. The treatment was well tolerated and analysis of cytokines associated with CAR-T cell cytotoxicity confirmed the absence of a severe cytokine storm. IFNγ was the only cytokine which was elevated during the expansion period of CAR-T cells, while IL-2, IL-6, TNFα and GM-CSF were barely detectable. In summary the characteristics of our new developed LV169-based platform make it suitable for further clinical translation which is underway.
Lentiviral vectors engineered for direct In Vivo delivery to resting T cells
Abstract Direct in vivo T cell engineering offers a new paradigm for CAR T delivery. We have evaluated several approaches to engineer lentiviral (LV) vectors capable of delivering CAR transgenes directly and selectively to T cells in vivo, within the lymphoid niche. Our goal was to develop an LV delivery platform that following intravenous administration can selectively bind and activate T cells, deliver and integrate the (CAR) transgene into genomic DNA, and drive CAR expression on the T cell surface. Further requirements were that the retargeted LV should be associated with minimal off-target transduction of tumor cells and normal host tissues and should be manufacturable at titers sufficient for human application. Our strategy for retargeting has been to modify the trimeric VSV-G protein, which is well established for efficient LV pseudotyping. Of the approaches evaluated, three retargeting platforms have proven to be effective: direct covalent display, indirect covalent display, and G-capping. Direct covalent display. This (LV-169) approach uses chimeric VSV-G protein that contains a CD3-targeting ligand displayed as a N-terminal extension of VSV-G protein that has been mutated to ablate (blind) its interaction with the LDL receptor. Chimeric and nonchimeric blinded G proteins are co- incorporated into LV particles within mixed envelopes which bind to CD3. Upon binding to cell surface CD3, the engineered particles activate T-cells and enter acidifying endosomes, whereupon they trigger membrane fusion and deliver their payloads. LV-169 displaying an anti-human CD3 scFv selectively transduced resting human T cells in PBMC cultures, in fresh human whole blood and following intravenous administration to humanized mice. In immunocompetent Cre reporter mice, surrogate vectors displaying anti-murine CD3 scFv selectively transduced lymph node resident T cells, with off-target transduction being limited to tissue-resident macrophages. To eliminate the incorporation of CAR protein into the LV-169 envelope, which can lead to highly undesirable transduction of tumor cells expressing the CAR target, we placed the CAR transgene in reverse to 5'LTR orientation, downstream of a T-cell specific promoter/enhancer. In vivo efficacy of LV-169-BCMA-CAR was demonstrated in humanized mice bearing disseminated OPM-2 myeloma tumors. Clinical translation of this construct is now underway. Indirect covalent display. In this G-protein engineering approach, a short peptide (SPY-tag) is displayed as an N-terminal extension of the LDLR-blinded VSV-G protein. The SPY-tagged LV vectors are then covalently modified to display a CD3-targeting ligand by simply mixing them at room temperature with a bifunctional fusion protein consisting of the SPY-catcher and the CD3 ligand. Under these conditions, the SPY-catcher and the SPY-tag spontaneously form a covalent isopeptide bond. The CD3 ligand-modified LV particles were shown to specifically activate and transduce T cells ex vivo within human PBMC cultures. G-capping. In the final approach, the VSV-G protein is not genetically modified. Instead, a “capping” protein crosslinker that binds directly to the unmodified G protein on preformed LV particles is used to mask their LDLR binding sites and redirect them to interact with CD3. Mixing of the CD3-targeted capping protein with traditional G-pseudotyped LV particles leads to efficient binding of the cap to the trimeric G proteins. The cap-modified LV are unable to interact with LDLR but interact efficiently with CD3. CD3-capped LV particles were highly specific and efficient in human T cell activation and transduction in PBMC cultures. The association between the G protein and the bound cap is highly stable during freeze-thaw cycles and at room temperature, a critical attribute of this platform to facilitate the manufacture of a clinically and commercially viable LV product. In summary, we have developed three translationally relevant platform technologies for the generation of LV particles capable of delivering CAR transgenes specifically and efficiently to resting niche-resident T cells after intravenous administration. Manufacturing studies are underway and, in the case of the LV-169 platform, clinical translation is already in progress.
Phase II study of bendamustine, rituximab, and venetoclax (BR-VEN) for the front-line treatment of Mantle Cell Lymphoma (MCL) in patients ≥60 years old; Updated survival and minimal residual disease (MRD) analysis of precog PrE0405
Abstract Introduction With a median age of 60-70 years at diagnosis, many patients with MCL are ineligible for aggressive treatment. Bendamustine and rituximab (BR) is a standard therapy for older patients with MCL. Venetoclax (VEN) has shown pre-clinical evidence of synergy with chemotherapy. Thus, PrE0405 was designed to evaluate the addition of VEN to BR in previously untreated older patients with MCL. We have previously reported on response rate and short-term survival (Portell et al. ASH 2023). Here, we update survival and include minimal residual disease (MRD) at end of treatment (EOT). Methods Eligible patients included those that were previously untreated and diagnosed with MCL by presence of t(11;14) or cyclin D1 expression. Patients must have been ≥60 years of age at the start of therapy with a good performance status (ECOG 0-2). Adequate marrow and organ function was required, specifically a creatinine clearance ≥ 40 ml/min. Eligible subjects were treated with bendamustine 90mg/m2 D1-2 and rituximab 375mg/m2 IV D1 every 28 days for a planned 6 cycles of therapy. For patients ≥75 years, 70mg/m2 of bendamustine was allowed. VEN was given concurrently with BR. During Cycle 1, VEN was dose escalated weekly, as done in chronic lymphocytic leukemia, from 20mg to 200mg. For Cycle 2-6, VEN was administered as 400mg PO daily on days 1-10 only. Maintenance rituximab was encouraged but was per investigator discretion. Primary end point was PET-negative complete remission (CR) at EOT by Lugano Criteria and was confirmed by a negative bone marrow biopsy if involved at screening. MRD was assessed at EOT by next-generation sequencing (Clonoseq). Amended accrual goal was 33 patients with a planned 32 being eligible and treated. This provided an 81% statistical power to detect a 17% difference in CR rate (from 60% [E1411, Smith et al Blood 2024] to 77%) using an exact binomial test with a 1-sided alpha of 11.6%. Thus, BR-VEN would be considered promising if 23 or more subjects attained a CR. Results From 1/2020 to 3/2022, 33 subjects were enrolled, deemed eligible, and treated on study. Subjects were followed until 7/2024. Median age was 71 (range 61-80) and 76% (n=25) were male. All but 1 subject (97%, n=32) were White. MIPI was high in 67% (n=22), intermediate in 27% (n=9) and low in 6% (n=2). Ki67 was available in 25 (76%) subjects and was ≥30% in 14 (56%) and ≥50% in 7 (28%). Only one subject started bendamustine treatment at 70mg/m2; though 6 others had dose reductions during treatment. Thirty (90%) subjects completed all 6 cycles of therapy. Maintenance rituximab was administered in 19 (56%) of subjects and 9 completed all 12 recommended doses. Treatment was generally well tolerated. During BR-VEN, Grade ≥3 treatment-related adverse events (TRAE) occurring in >10% (i.e., 4 or more) of subjects were neutropenia (n=8, 24%), and thrombocytopenia (n=5, 15%). Other common TRAE of all grades were nausea/vomiting (n=19, 58%), diarrhea (n=10, 30%), and fatigue (n=19, 58%). At EOT with BR-VEN, overall response and CR rate was 97% (32 of 33) and 85% (28 of 33) respectively. The study met its primary endpoint of at least 23 subjects with a CR best response (p=0.002). EOT MRD sample (blood or marrow aspirate) was available for 28 subjects (85%). At EOT, MRD was undetectable for 100% (n=28) of evaluable subjects at a sensitivity of 10-4 and 10-5. At a sensitivity of 10-6, 64% (n=18) were undetectable, 4% (n=1) were detectable and 32% (n=9) were indeterminate. With a median follow up of 39.1 months, 3-year progression free survival (PFS) was 68.9 and 3-year overall survival (OS) was 70.0%. There were 11 total PFS events during follow up. Four subjects in remission died due to COVID-19, 1 died from influenza, one died from HSV encephalitis, and 2 others died from other causes. Two subjects died shortly after progression and 1 subject is alive following disease progression. As this study enrolled during the height of the COVID-19 pandemic, a sensitivity analysis was performed censoring the COVID-19 attributable deaths – PFS and OS at 3 years was 78.7% and 80.0%. Conclusions BR-VEN was generally well tolerated as induction therapy in older patients with MCL. It achieved a high CR rate of 85% with 100% MRD undetectable rate at 10-5 sensitivity in those evaluable. However, there were competing risks for survival in this older population as, of the 11 PFS events, only 3 events were due to progression; 8 were due to death without progression.
Burden of Central Nervous System Cancer in the United States, 1990-2021
Importance Primary brain and central nervous system cancer (collectively referred to as CNS cancer) comprises 2% of all human cancers and poses significant health and economic challenges in the United States. Objective To analyze CNS cancer burden in the US, stratified by time, location (state and division), sex, age group, and Sociodemographic Index (SDI). Design, Setting, and Participants This cross-sectional study involved a repeated analysis of Global Burden of Disease Study (GBD) 2021 data in 2024. Using data from 183 sources, CNS cancer metrics in the US were estimated across states and years. US CNS cancer metrics across all sexes and age groups were included in the GBD. Exposure CNS cancer diagnosis. Main Outcomes and Measures Overall and age-standardized estimates of the incidence, prevalence, mortality, disability-adjusted life-years (DALYs), years of life lost, and years lived with disability per 100 000 population, including 95% uncertainty intervals (UIs), and time trends. Results In 2021, for all age groups and sexes across the US, there were 31 780 incident cases (95% UI, 29971.1 to 32843.9). Age-standardized incidence, DALYs, and mortality rates per 100 000 population were 6.91 (95% UI, 6.58 to 7.12), 134.38 (95% UI, 129.83 to 137.95), and 4.1 (95% UI, 3.87 to 4.22), respectively. Despite no significant change observed in the overall incidence between 1990 and 2021, DALY and mortality rates decreased by 15.77% (95% UI, −17.75% to −13.68%) and 8.41% (95% UI, −11.09% to −6.22%), respectively. Substantial geographic variability was noted. Mississippi, Alabama, Kentucky, and Kansas (West North Central and East South Central divisions) and West Virginia faced persistently high burdens over the past 30 years. Sex differences were evident; disease burden was consistently higher in males compared with females. Age-specific estimates showed a bimodal distribution: the youngest group (&lt;5 years) showed a significant decrease in incidence rate (−34.42% to −11.56%), whereas older age groups (&gt;70 years) experienced increasing trends. DALYs and mortality rates were negatively correlated with SDI (ρ = −0.6860 and ρ = −0.6391; P &lt; .001). Conclusions and Relevance These findings provide valuable insights into the CNS cancer burden across the US by age, sex, location, and SDI, enabling better public health status assessments, health care policy restructuring, and resource redistribution for improved care.
Abstract 4366122: Outcomes of Transcatheter Mitral Repair in Cardiogenic Shock With and Without Mechanical Circulatory Support
Background: Severe mitral regurgitation (MR) in cardiogenic shock (CS) presents unique therapeutic challenges, especially in patients with prohibitive surgical risk. Transcatheter edge-to-edge repair (TEER) with MitraClip offers a less invasive alternative, yet optimal strategies for hemodynamic support in this setting remain unclear. Methods: We conducted a retrospective study of patients undergoing MitraClip implantation for severe MR and CS between 2018 and 2024 at a tertiary academic center. Of 440 screened cases, 47 met CS criteria and were stratified based on receipt of periprocedural Impella support. Clinical, procedural, and survival outcomes were compared between Impella-supported and unsupported cohorts using appropriate statistical methods. Results: Among the 47 patients, 24 received Impella support and 23 did not. The Impella group had greater illness severity, including higher rates of preprocedural intubation (75.0% vs. 43.5%) and SCAI stage D shock (50.0% vs. 13.0%). Despite these differences, procedural success was 100% in both groups. In-hospital (8.3% vs. 8.7%), 30-day (12.5% vs. 8.7%), and 1-year mortality (25.0% vs. 26.0%) were similar between Impella and non-Impella patients, respectively. Impella recipients had longer hospital stays (median 18 vs. 11 days; p=0.032) and higher 1-year readmission rates (55.0% vs. 21.7%; p=0.024), reflecting baseline acuity. There were no differences in major procedural complications or re-intervention rates. Conclusions: MitraClip implantation in CS patients supported with Impella is feasible and safe. Despite significantly worse hemodynamic profiles, outcomes were comparable to those without mechanical support. These findings suggest a potential role for tailored Impella use in expanding TEER to critically ill patients and underscore the need for prospective studies to guide support strategies in high-risk MR intervention.
Characterization of Spirometric Response to Standard-of-care Treatment in Lung Allograft Recipients With Bronchiolitis Obliterans and the Utility of Spirometric Criteria for Rescue Therapy: Implications for the Design of Risk-stratified Clinical Trials
Background. The spirometric response to standard-of-care (SOC) immunosuppressive therapy for the management of bronchiolitis obliterans syndrome (BOS) has been sparsely reported in the literature. Data from a Medicare-approved Registry were analyzed to characterize the effectiveness/durability of a wide range of SOC interventions to manage the decline of lung function and to validate the study spirometric criteria for initiation of rescue therapy. Methods. Lung transplant recipients with refractory BOS at 21 US collaborating centers were enrolled in the Registry. Data included both nonspirometric (eg, demographic, Immunosuppressive Regimens for management of BOS) and spirometric parameters (ie, forced expiratory volume in 1 s [FEV 1 ] measurements and derived indices). The utility of study FEV 1 criteria for treatment (ie, statistically significant rate of FEV 1 decline >30 mL/mo) was evaluated by comparing the spirometric course between participants who met or did not meet this criterion. Results. Only 21% of participants treated with SOC therapy had >50% decrease (76 ± 25% decrease) in the rate of FEV 1 decline. Although 51% of participants had a partial response (rate of FEV 1 decline decreased on average 71%), 49% of participants had a substantial increase (mean increase 224%). The FEV 1 criterion for treatment was able to identify 19% of participants (48/258) who achieved durable stabilization (ie, nonsignificant rate of FEV 1 <30 mL/mo) with SOC therapy. Conclusions. Patients with BOS have a widely variable response to SOC therapy. Our findings support the use of FEV 1 rate of decline to assess response to SOC therapy and to ensure appropriate assignment of participants with refractory BOS to rescue therapy treatment cohorts.
Extended Survival in a Dog with Primary Bone Hemangiosarcoma Following Treatment with Neoadjuvant Oncolytic Virotherapy and Standard of Care
A three year old male neutered mixed breed dog presented with a mass on the right carpus and accompanying lameness. A Jamshidi bone biopsy was performed, and histopathology results were consistent with a sarcoma. The dog received oncolytic virotherapy (OV) with vesicular stomatitis virus (VSV) as part of a clinical trial in dogs with osteosarcoma (OSA). Ten days after VSV treatment, the affected limb was amputated, and histopathology was consistent with intramedullary HSA. Considering the new diagnosis, standard doxorubicin chemotherapy was prescribed. With this combination of therapies, the dog had an extended survival of more than seven years and remains alive at the time of writing. This is the first case report documenting OV given in conjunction with the standard of care for canine appendicular HSA.
Identification of Surrogate Outcome Biomarkers in Lung Allograft Recipients With Bronchiolitis Obliterans: Implications for Randomized Controlled Trials
BACKGROUND. We developed a prospective, multicenter “registry” to evaluate the effect of extracorporeal photopheresis for lung transplant recipients who develop chronic lung allograft dysfunction (CLAD) with the bronchiolitis obliterans syndrome (BOS) phenotype (CLAD/BOS) and who are refractory to conventional standard-of-care therapy. METHODS. Data from 258 lung transplant recipients enrolled in the Registry between April 2015 and April 2022 were included in this analysis. All recorded parameters (eg, demographics), including forced expiratory volume in 1 s (FEV1) measurements and indices (FEV1% baseline, FEV1 rate of decline) at several time periods, were included in multivariate linear/logistic and Kaplan-Meier analyses to evaluate potential associations with survival. RESULTS. Mortality at 6 and 12 mo after CLAD/BOS diagnosis was 5% and 14%, whereas mortality at 6 and 12 mo after enrollment was 15% and 26%, respectively. The primary cause of death in the cohort was respiratory failure or graft failure (74%). Rate of FEV1 decline (log) at enrollment was independently associated with survival (log days) from CLAD/BOS diagnosis and enrollment (r = 0.55 and r = 0.3, respectively). The rates of FEV1 decline among survivors were lower (–77 ± 89 mL/mo) compared with nonsurvivors (–148 ± 155 mL/mo) at 6 mo after enrollment (P = 0.0001). CONCLUSIONS. The rate of FEV1 decline quantified using at least 5 FEV1 measurements is a robust surrogate outcome. We plan to use these findings to revise our randomized controlled trial to facilitate risk adjustment using FEV1 rate of decline strata at enrollment and as a scientifically valid surrogate for outcome.