SNS812

SNS812 is a first-in-class, fully modified small interfering RNA (siRNA) drug developed for the treatment of COVID-19. It acts via RNA interference (RNAi), specifically targeting and cleaving a highly conserved region of the SARS-CoV-2 genome—namely, the gene encoding RNA-dependent RNA polymerase (RdRp). This mechanism inhibits viral replication and promotes elimination of the virus from infected cells. Unlike vaccines and antibodies that target mutable spike proteins, SNS812’s approach is designed to maintain efficacy against a broad spectrum of SARS-CoV-2 variants, including high immune-escape strains such as JN.1, KP1-4, LB.1, BA.2, and XBB[1][7][8]. The drug is administered via inhalation as an aerosolized therapy. Clinical trials have demonstrated that SNS812 has a favorable safety profile with no serious adverse events or immunogenicity concerns in healthy volunteers or patients with mild-to-moderate COVID-19[5][6][8]. In Phase 2 studies involving 135 subjects across multiple hospitals in Taiwan from late 2023 to mid-2024, SNS812 showed statistically significant improvements over placebo in reducing time to symptom resolution—including fever, sore throat, shivers/chills, headache, shortness of breath—and accelerating viral clearance[5][7]. The median time to achieve viral negativity was reduced to approximately 2.9 days at higher doses compared to placebo[7].

Other names

Inhaled MBS-COV