Safety and biodistribution of NanoligomersTM targeting SARS-CoV-2 genome for treatment of COVID-19 (preprint)

As the world braces to enter its third year in the coronavirus disease 2019 (COVID-19) pandemic, the need for accessible and effective antiviral therapeutics continues to be felt globally. The recent surge of Omicron variant cases has demonstrated that vaccination and prevention alone cannot quell the spread of highly transmissible variants. A safe and nontoxic therapeutic with an adaptable design to respond to the emergence of new variants is critical for transitioning to treatment of COVID-19 as an endemic disease. Here, we present a novel compound, called SBCoV202, that specifically and tightly binds the translation initiation site of RNA-dependent RNA polymerase within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome, inhibiting viral replication. SBCoV202 is a Nanoligomer,TM a molecule that includes peptide nucleic acid sequences capable of binding viral RNA with single-base-pair specificity to accurately target the viral genome. The compound has been shown to be safe and nontoxic in mice, with favorable biodistribution, and has shown efficacy against SARS-CoV-2 in vitro. Safety and biodistribution were assessed after three separate administration methods, namely intranasal, intravenous, and intraperitoneal. Safety studies showed the Nanoligomer caused no outward distress, immunogenicity, or organ tissue damage, measured through observation of behavior and body weight, serum levels of cytokines, and histopathology of fixed tissue, respectively. SBCoV202 was evenly biodistributed throughout the body, with most tissues measuring Nanoligomer concentrations well above the compound KD of 3.37 nM. In addition to favorable availability to organs such as the lungs, lymph nodes, liver, and spleen, the compound circulated through the blood and was rapidly cleared through the renal and urinary systems. The favorable biodistribution and lack of immunogenicity and toxicity set Nanoligomers apart from other antisense therapies, while the adaptability of the nucleic acid sequence of Nanoligomers provides a defense against future emergence of drug resistance, making these molecules an attractive potential treatment for COVID-19.

Small Airway Disease as long-term Sequela of COVID-19: Use of Expiratory CT despite Improvement in Pulmonary Function test (preprint)

Background- It is important to understand the spectrum of pulmonary diseases that patients are presenting after recovery from initial SARS-CoV-2 infection. We aim to study small airway disease and changes in Computed Tomography (CT) and pulmonary function tests (PFTs) with time. Methods: This is retrospective observation study including adult patients with confirmed SARS-CoV-2 infection with at-least two CT scans either during acute (defined as < 1 month) or subacute (1-3 months) or chronic (>3months) phase after positive test. Radiological features and follow up PFTs were obtained. Results: 22 patients met the inclusion criteria with mean age 57.6 years (range 36-83). Out of these,18 (81.81%) were hospitalized. Mean duration of diagnosis to CT and PFT was 192.68 (112-385) days and 161.54 (31-259) days respectively. On PFTs, restrictive pulmonary physiology was predominant finding during subacute 56.25% (9/16) and chronic phases 47% (7/15). PFTs improved significantly with time {FEV1((p=0.0361), FVC (p=0.0341), FEF 25%-75% (p=0.0259) and DLCO (p=0.0019)}, but there was persistent air trapping in the expiratory chronic phase CT. There was resolution of ground glass opacity, consolidation, and bronchiectasis however air trapping increased with time in 41.61% (10/21) of subacute CTs compared to 81.25% (13/16) in chronic CTs. Conclusion - Our study shows evidence of airway as well as parenchymal disease as relatively long-term sequel of SARS-CoV-2 infection. It also highlights the natural course and spontaneous recovery of some radiological and pulmonary function test abnormalities over time with evidence of persistent small airway disease (air trapping) on expiratory CT imaging months after infection.

Small Airways Disease is a Post-Acute Sequelae of SARS-CoV-2 Infection (preprint)

Background The sequelae of SARS-CoV-2 infection on pulmonary structure and function remain incompletely characterized. Methods Adults with confirmed COVID-19 who remained symptomatic more than thirty days following diagnosis were enrolled and classified as ambulatory, hospitalized or requiring the intensive care unit (ICU) based on the highest level of care received during acute infection. Symptoms, pulmonary function tests and chest computed tomography (CT) findings were compared across groups and to healthy controls. CT images were quantitatively analyzed using supervised machine-learning to measure regional ground glass opacities (GGO) and image-matching to measure regional air trapping. Comparisons were performed using univariate analyses and multivariate linear regression. Results Of the 100 patients enrolled, 67 were in the ambulatory group. All groups commonly reported cough and dyspnea. Pulmonary function testing revealed restrictive physiology in the hospitalized and ICU groups but was normal in the ambulatory group. Among hospitalized and ICU patients, the mean percent of total lung classified as GGO was 13.2% and 28.7%, respectively, and was higher than in ambulatory patients (3.7%, P<0.001). The mean percentage of total lung affected by air trapping was 25.4%, 34.5% and 27.2% in the ambulatory, hospitalized and ICU groups and 7.3% in healthy controls (P<0.001). Air trapping measured by quantitative CT correlated with the residual volume to total lung capacity ratio (RV/TLC; {rho} =0.6, P<0.001). Conclusions Air trapping is present in patients with post-acute sequelae of COVID-19 and is independent of initial infection severity, suggesting obstruction at the level of the small airways. The long-term consequences are not known.

The Great Deceiver: miR-2392's Hidden Role in Driving SARS-CoV-2 Infection (preprint)

MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation that have a major impact on many diseases and provides an exciting avenue towards antiviral therapeutics. From patient transcriptomic data, we have discovered a circulating miRNA, miR-2392, that is directly involved with SARS-CoV-2 machinery during host infection. Specifically, we found that miR-2392 was key in driving downstream suppression of mitochondrial gene expression, increasing inflammation, glycolysis, and hypoxia as well as promoting many symptoms associated with COVID-19 infection. We demonstrate miR-2392 is present in the blood and urine of COVID-19 patients tested, but not detected in COVID-19 negative patients. These findings indicate the potential for developing a novel, minimally invasive, COVID-19 detection method. Lastly, using both in vitro human and in vivo hamster models, we have developed a novel miRNA-based antiviral therapeutic targeting miR-2392 that significantly reduces SARS-CoV-2 viability and may potentially inhibit a COVID-19 disease state in the host.