Sorrento Releases Preclinical Data for STI-1499 (COVI-Guard) and STI-2020 (COVI-AMG), Potent Neutralizing Antibodies Against SARS-CoV-2

• In preclinical studies, both STI-1499 and STI-2020 demonstrated potent neutralizing activity against SARS-CoV-2 virus isolates, including the emerging Spike D614G variant virus.
  
• Both STI-1499 and STI-2020 demonstrated protective activities against SARS-CoV-2 infection in Syrian golden hamsters.
• At day 5, STI-2020 at 500 µg reduced virus load in hamster lungs to undetectable levels in 100% of animals tested, whereas STI-1499 at 2,000 µg reduced virus load below the detection limit in 60% of animals tested and showed a 10-fold reduction in the remaining 40% of animals.
  

SAN DIEGO, Sept. 28, 2020 (GLOBE NEWSWIRE) -- Sorrento Therapeutics, Inc. (Nasdaq: SRNE, “Sorrento”) released preclinical data reporting on COVI-GUARD (STI-1499) and COVI-AMG (STI-2020; Affinity Matured COVI-Guard) neutralizing antibodies (nAbs) against SARS-CoV-2 as well as a D614G virus variant infection in a preprint publication, which can be found at {https://biorxiv.org/cgi/content/short/2020.09.27.316174v1}. Both STI-1499 and STI-2020 demonstrated potent neutralizing activities against SARS-CoV-2 virus infection in preclinical models. STI-1499 nAb has been cleared by the FDA for a Phase 1 clinical trial in hospitalized COVID-19 patients. STI-2020 is an affinity-matured version of the COVI-GUARD nAb and has demonstrated a greater than 50-fold increase in potency in in vitro experiments.

In preclinical cell-based assay, both STI-1499 and STI-2020 have shown 100% in vitro neutralization of SARS-CoV-2 at concentrations of 6 µg/ml and 78 ng/ml, respectively. The neutralization activity at these concentrations protected against both SARS-CoV-2 and the highly contagious Spike D614G isolate.

Dr. Slobodan Paessler’s laboratory at the University of Texas Medical Branch at Galveston (UTMB) has generated promising preclinical animal data for STI-1499 and STI-2020 nAbs in a Syrian golden hamster model infected with SARS-CoV-2. A few highlights of the data from the most recent STI-2020 study:

• Hamsters infected with SARS-CoV-2 and then treated with a single dose of 500 µg STI-2020 started gaining weight within 48 hours of STI-2020 administration, as compared to control animals that steadily lost weight for 5 days before recovery.
• At day 5, STI-2020-treated (500 µg) hamsters had gained 5% weight, versus a weight loss of about 10% for the control animals (15% difference).
• At day 5, all STI-2020-treated (500 µg) hamsters (5 out of 5 analyzed animals) had undetectable virus load in lungs as compared to the lungs of animals in the control group, where more than 1,000 infectious viral particles per gram of tissue were readily detected.