Sorrento Therapeutics (NSDQ:SRNE) revealed that its late-stage preclinical main protease inhibitor STI-1558 inhibited omicron virus entry and replication in cell-based assays. Prior research indicates that STI-1558 offers broad-spectrum activity against SARS-CoV-2. STI-1558 is distinct from Pfizer’s SARS-CoV-2 drug Paxlovid (nirmatrelvir), which pairs the SARS-CoV-2-3CL protease inhibitor PF-07321332 with ritonavir, which works as a pharmacokinetic enhancer.…