Summary of COVID-19 SNS812 studies

1. Chen et al., Safety and antiviral activity of inhaled siRNA SNS812 for treatment of mild-to-moderate COVID-19: a phase 2 randomized trial

90 patient SNS812 early treatment RCT: 52% improved recovery (p=0.002), 45% greater improvement (p=0.01), 14% improved viral load (p=0.04), and 19% faster viral clearance (p=0.007).
RCT 135 patients with mild to moderate COVID-19 showing significant efficacy of inhaled SNS812 (siRNA targeting SARS-CoV-2 RdRP) for reducing viral load and accelerating symptom resolution. The trial randomized patients to 200mg, 100mg, or placebo arms, with treatment initiated within 3 days of symptom onset. The 200mg group demonstrated significantly faster viral clearance and greater viral load reduction starting from day 1. Symptom improvement showed dose-dependent effects with significant reduction in time to resolution for 6 of 14 symptoms, including shortness of breath and loss of taste/smell. The siRNA targets a highly conserved region of the viral RNA-dependent RNA polymerase gene and showed efficacy against multiple Omicron variants.
Mar 2025, J. Biomedical Science, https://link.springer.com/10.1186/s12929-026-01284-5, https://c19p.org/chen52