Odelya E. Pagovich

Sepsis causes approximately 11 million deaths globally each year. Whole-genome sequencing (WGS) of founder populations offers a unique opportunity for discovery of genes related to susceptibility of sepsis. We performed GWAS and EXWAS on WGS data for n=210 Arab ICU patients (n=68 sepsis cases, n=142 controls, other ICU-related disorders) and prioritized n=40 associated deleterious founder variants in n=31 genes (REGENIE Firth regression p < 0.05; CADD score > 20; enriched AAF vs AllofUs/gnomAD), including a novel start-loss variant in UBE2L3 (c.2T>G; p.Met1?; CADD = 25.6; SIFT = 0.001) in sepsis cases (3/68 vs 0/142 controls; Fisher’s exact P = 0.026). In All of Us (AoU), UBE2L3 missense burden was associated with bacterial infection (n=26,939 cases; SKAT-O P = 2.38×10⁻³; OR=23.10; 95% CI = [0.63–845.27]). LLM AI models fine-tuned for drug development scored UBE2L3 a 7.8 of 10 as a drug target for sepsis, consistent with mouse UBE2L3 KO showing increased IL-1Beta mediated inflammation in sepsis.

Disclosure: J. Mendell: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. Y. Wang: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. B.A. Olenchock: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. S. Podgrabinska: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. O.E. Pagovich: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. E.A. Oral: Advisory Board Member; Self; Regeneron Pharmaceuticals. Consulting Fee; Self; Third Rock Ventures, Rejuvenate Inc. Grant Recipient; Self; Amryt Pharamceuticals, Ionis Pharmaceuticals Inc., Gemphire Theraputics. Research Investigator; Self; Regeneron Pharmaceuticals, Novo Nordisk, Rhythm pharmaceuticals, Fractyl Laboratories, GI Dynamics. Other; Self; Has IP rights to Metreleptin manufactured by Amryt Pharmaceuticals and receives royalty payments. R.J. Brown: Research Investigator; Self; Regeneron Pharmaceuticals. J. Davis: Employee; Self; Regeneron Pharmaceuticals. Stock Owner; Self; Regeneron Pharmaceuticals. Background: Generalized lipodystrophy (GLD) is characterized by deficiency of adipose tissue and, consequently, low levels of the adipose-derived hormone leptin. Leptin deficiency in GLD causes metabolic abnormalities and complications that are often refractory to treatment with usual glucose/lipid-lowering agents. Mibavademab is a first-in-class human leptin receptor (LEPR) agonist monoclonal antibody that activates LEPR. We investigated baseline serum leptin in patients with GLD, pharmacokinetics (PK) of mibavademab, and soluble LEPR (sLEPR) levels from a phase 2 study. Methods: In this phase 2 trial (NCT04159415), patients with GLD (≥12 yrs old) underwent a single-blind placebo run-in, followed by 1:1 randomization to one of two fixed sequence arms: Treatment A (placebo for 8 weeks, then mibavademab low dose for 8 weeks, then mibavademab high dose for 20 weeks) or Treatment B (mibavademab low dose for 8 weeks, then mibavademab high dose for 28 weeks). A loading dose of intravenous mibavademab was administered before low-dose treatment. Mibavademab and sLEPR concentrations in serum were serially measured during mibavademab treatment using validated bioanalytical methods. Results: Sixteen patients were enrolled with median body weight (BW) of 51 kg, corresponding to the approximate BW cut point for mibavademab. Baseline serum leptin was below the lower limit of quantitation (0.078 mg/L) in 5 patients with a median concentration of 0.345 mg/L (n=15). Baseline sLEPR concentrations with Treatments A and B were 30.6 and 33.9 μg/L, respectively. At Week 8, mean (SD) mibavademab trough concentrations (C_trough) with Treatments A and B were 0 (0) and 1.61 (1.71) mg/L, respectively. Low-dose PK were less than predicted from a first in human study in healthy volunteers with higher leptin levels, reflecting higher target mediated clearance in patients with GLD. At Week 16, C_trough for Treatments A and B increased to 2.31 and 43.0 mg/L, respectively, but were still below predicted. At Week 36, C_trough for Treatments A and B were 60 (35.3) and 67.7 (44.2) mg/L, respectively. Clinically meaningful metabolic benefit (i.e reflected by reductions in fasting triglycerides and glycated hemoglobin) was observed at Week 36 with both Treatments A and B. Conclusions: Mibavademab concentrations by Week 36 were associated with clinically meaningful improvement in metabolic parameters. Presentation: Friday, June 16, 2023

Metachromatic leukodystrophy, a fatal pediatric neurodegenerative lysosomal storage disease caused by mutations in the arylsulfatase A ( ARSA ) gene, is characterized by intracellular accumulation of sulfatides in the lysosomes of cells of the central nervous system (CNS). In previous studies, we have demonstrated efficacy of AAVrh.10hARSA, an adeno-associated virus (AAV) serotype rh.10 vector coding for the human ARSA gene to the CNS of a mouse model of the disease, and that catheter-based intraparenchymal administration of AAVrh.10hARSA to the CNS of nonhuman primates (NHPs) white matter results in widespread expression of ARSA. As a formal dose-escalating safety/toxicology study, we assessed the safety of intraparenchymal delivery of AAVrh.10hARSA vector to 12 sites in the white matter of the CNS of NHPs at 2.85 × 10 ¹⁰ (total low dose, 2.4 × 10 ⁹ genome copies [gc]/site) and 1.5 × 10 ¹² (total high dose, 1.3 × 10 ¹¹ gc/site) gc, compared to AAVrh.10Null (1.5 × 10 ¹² gc total, 1.3 × 10 ¹¹ gc/site) as a vector control, and phosphate buffered saline for a sham surgical control. No significant adverse effects were observed in animals treated with low dose AAVrh.10hARSA. However, animals treated with the high dose AAVrh.10ARSA and the high dose Null vector had highly localized CNS abnormalities on magnetic resonance imaging scans at the sites of catheter infusions, and histopathology demonstrated that these sites were associated with infiltrates of T cells, B cells, microglial cells, and/or macrophages. Although these findings had no clinical consequences, these safety data contribute to understanding the dose limits for CNS white matter direct intraparenchymal administration of AAVrh.10 vectors for treatment of CNS disorders.

Background: Eosinophils are specialized granulocytic effector cells that store and release highly active mediators used in immune defense. Eosinophils are also implicated in the pathogenesis of allergic disorders, including eosinophilic esophagitis (EoE), a chronic disorder characterized by infiltration of eosinophils into the esophagus and release of mediators that damage tissue, resulting in gastrointestinal morbidity, food impaction, and dysphagia. Treatment with elimination diets and/or topical corticosteroid therapy slow disease progression, but are complicated by adverse effects, limited compliance, and loss of response to therapy. We hypothesized that a single administration of an adeno‐associated virus (AAV) coding for an anti‐eosinophil monoclonal antibody that induces eosinophil clearance (anti‐Siglec‐F) would treat on a persistent basis a murine model of EoE.Methods: A mouse model of peanut‐induced EoE that mimics the human disease was established by sensitization and challenge with peanut extract. After challenge, these mice exhibited an EoE phenotype demonstrated by elevated levels of blood eosinophils, infiltration of eosinophils in the esophagus with associated esophageal remodeling and food impaction.Results: The mice were treated with a single intravenous administration (10¹¹ genome copies) of AAVrh.10mAnti‐Eos, a serotype rh.10 AAV vector coding for an anti‐Siglec‐F monoclonal antibody. Vector administration resulted in persistent, high levels of anti‐Siglec‐F antibody expression. Administration of AAVrh.10mAnti‐Eos to the mouse model of EoE reduced blood (P < 0.02) and esophageal eosinophil numbers (P < 0.002) protected from esophageal tissue remodeling and minimized food impaction.Conclusion: These results suggest that a single treatment with AAVrh.10mAnti‐Eos has the potential to provide persistent therapeutic benefit to patients with EoE.

Alpha 1-antitrypsin (AAT) deficiency, a hereditary disorder characterized by low serum levels of functional AAT, is associated with early development of panacinar emphysema. AAT inhibits serine proteases, including neutrophil elastase, protecting the lung from proteolytic destruction. Cigarette smoke, pollution, and inflammatory cell–mediated oxidation of methionine (M) 351 and 358 inactivates AAT, limiting lung protection. In vitro studies using amino acid substitutions demonstrated that replacing M351 with valine (V) and M358 with leucine (L) on a normal M1 alanine (A) 213 background provided maximum antiprotease protection despite oxidant stress. We hypothesized that a onetime administration of a serotype 8 adeno-associated virus (AAV8) gene transfer vector coding for the oxidation-resistant variant AAT (A213/V351/L358; 8/AVL) would maintain antiprotease activity under oxidant stress compared with normal AAT (A213/M351/M358; 8/AMM). 8/AVL was administered via intravenous (IV) and intrapleural (IPL) routes to C57BL/6 mice. High, dose-dependent AAT levels were found in the serum and lung epithelial lining fluid (ELF) of mice administered 8/AVL or 8/AMM by IV or IPL. 8/AVL serum and ELF retained serine protease–inhibitory activity despite oxidant stress while 8/AMM function was abolished. 8/AVL represents a second-generation gene therapy for AAT deficiency providing effective antiprotease protection even with oxidant stress.

Aging involves multiple biologically complex processes characterized by a decline in cellular homeostasis over time leading to a loss and impairment of physiological integrity and function. Specific cellular hallmarks of aging include abnormal gene expression patterns, shortened telomeres and associated biological dysfunction. Like all organs, the lung demonstrates both physiological and structural changes with age that result in a progressive decrease in lung function in healthy individuals. Cigarette smoking accelerates lung function decline over time, suggesting smoking accelerates aging of the lung. Based on this data, we hypothesized that cigarette smoking accelerates the aging of the small airway epithelium, the cells that take the initial brunt of inhaled toxins from the cigarette smoke and one of the primary sites of pathology associated with cigarette smoking. Using the sensitive molecular parameters of aging-related gene expression and telomere length, the aging process of the small airway epithelium was assessed in age matched healthy nonsmokers and healthy smokers with no physical manifestation of lung disease or abnormalities in lung function. Analysis of a 73 gene aging signature demonstrated that smoking significantly dysregulates 18 aging-related genes in the small airway epithelium. In an independent cohort of male subjects, smoking significantly reduced telomere length in the small airway epithelium of smokers by 14% compared to nonsmokers. These data provide biologic evidence that smoking accelerates aging of the small airway epithelium.

Background: As the multipotent progenitor population of the airway epithelium, human airway basal cells (BC) replenish the specialized differentiated cell populations of the mucociliated airway epithelium during physiological turnover and repair. Cultured primary BC divide a limited number of times before entering a state of replicative senescence, preventing the establishment of long-term replicating cultures of airway BC that maintain their original phenotype.Methods: To generate an immortalized human airway BC cell line, primary human airway BC obtained by brushing the airway epithelium of healthy nonsmokers were infected with a retrovirus expressing human telomerase (hTERT). The resulting immortalized cell line was then characterized under non-differentiating and differentiating air-liquid interface (ALI) culture conditions using ELISA, TaqMan quantitative PCR, Western analysis, and immunofluorescent and immunohistochemical staining analysis for cell type specific markers. In addition, the ability of the cell line to respond to environmental stimuli under differentiating ALI culture was assessed.Results: We successfully generated an immortalized human airway BC cell line termed BCi-NS1 via expression of hTERT. A single cell derived clone from the parental BCi-NS1 cells, BCi-NS1.1, retains characteristics of the original primary cells for over 40 passages and demonstrates a multipotent differentiation capacity into secretory (MUC5AC, MUC5B), goblet (TFF3), Clara (CC10) and ciliated (DNAI1, FOXJ1) cells on ALI culture. The cells can respond to external stimuli such as IL-13, resulting in alteration of the normal differentiation process.Conclusion: Development of immortalized human airway BC that retain multipotent differentiation capacity over long-term culture should be useful in understanding the biology of BC, the response of BC to environmental stress, and as a target for assessment of pharmacologic agents.

The production of gamma-amino butyric acid (GABA) is dependent on glutamate decarboxylases (GAD65 and GAD67), the enzymes that catalyze the decarboxylation of glutamate to GABA. Based on studies suggesting a role of the airway epithelial GABAergic system in asthma-related mucus overproduction, we hypothesized that cigarette smoking, another disorder associated with increased mucus production, may modulate GABAergic system-related gene expression levels in the airway epithelium.