Sorrento Therapeutics has announced the dosing of the first subject in a Phase I clinical trial of its oral therapy, STI-1558, in healthy subjects to treat Covid-19.
Designed as a standalone treatment and prevention of Covid-19 without ritonavir co-administration as a booster for CYP3A4 inhibition, the therapy is an inhibitor of SARS-CoV-2 main protease.
Set to be carried out in Australia, the trial will assess the tolerability, safety and pharmacokinetics of the main viral protease (Mpro) inhibitor, STI-1558, in single ascending doses (SAD) followed by multiple ascending doses (MAD) against placebo.
Once the Phase I trial concludes successfully, the company will initiate a global pivotal Phase II/III trial.
Sorrento Therapeutics chairman and CEO Dr Henry Ji said: “With data achieved from the preclinical studies and potential standalone treatment without requiring a pharmacokinetic booster, STI-1558 has the potential to be a best-in-class oral antiviral therapeutic for Covid-19, appropriate for patients taking multiple medications, without requiring extra monitoring or dose adjustments.
“Sorrento has initiated a large-scale manufacture synthesis for API and drug product to prepare for global commercial supply if STI-1558 is successfully developed.”
STI-1558 has showed potent antiviral activity against all variants of the virus that were studied, including Omicron in vitro after human bronchial epithelial cells infection.
Furthermore, the oral therapy demonstrated antiviral activity against the SARS-CoV-2 virus in a humanised transgenic mice model, in preclinical studies.
Additionally, STI-1558 is a Cathepsin L inhibitor that may block effective entry of the virus into host cells and is expected to work along with protease inhibition for protection against Covid-19.
In March this year, Sorrento received approval from the US Food and Drug Administration (FDA) to initiate the Phase II/III clinical trial of abivertinib to treat Covid-19 patients hospitalised with severe pneumonia.