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. Sorrento developed STI-1558 to offer optimized human liver microsomal stability to avoid the need for ritonavir.
The company anticipates that STI-1558 will thus have fewer issues with drug-drug interactions.
Sorrento also noted that STI-1558 inhibited pseudovirus entry into cells in an omicron S protein-mediated pseudovirus entry assay, whereas nirmatrelvir did not.
“With omicron becoming a globally dominant variant of SARS-CoV-2 in such a short period of time, we are focused on developing an effective therapeutic strategy for fighting the Omicron variant and future variants of concern, and most importantly, for preventing or overcoming drug resistance. Sorrento continues its commitment to develop and deliver effective anti-COVID therapies to save patient lives and end the pandemic,” said Dr. Henry Ji, CEO of Sorrento, in a press release.
SRNE shares rose 2.78% to $2.96.
Earlier this month, Sorrento got permission from the Brazilian Health Regulatory Agency (ANVISA) for a Phase 2a study involving its COVI-MSC allogeneic adipose-derived mesenchymal stromal cells.