What happened

Shares of Sorrento Therapeutics (SRNE.Q -13.51%) were surging 10.5% higher as of 11:07 a.m. EDT on Tuesday. The nice gain came following the company's announcement late Monday evening of encouraging preclinical data for its experimental COVID-19 antibody therapies STI-1499 and STI-2020.

So what

Sorrento announced that both experimental antibody therapies showed solid neutralizing activity against the SARS-CoV-2 virus in preclinical testing with Syrian golden hamsters. On the fifth day following treatment, a 500 microgram dose of STI-2020 reduced the viral load in the lungs to undetectable levels in 100% of the hamsters tested. A 2,000 microgram dose of STI-1499 reduced the viral load below detectable levels in 60% of hamsters tested. It also achieved a tenfold reduction in the other 40% of hamsters in the preclinical study.

Gloved hand stopping wood dominos spelling "COVID-19" from toppling other wood dominos.

Image source: Getty Images.

How good were these results? In a statement, Sorrento CEO Henry Ji said "STI-2020 is our most promising SARS-CoV-2 antibody so far." He added that the experimental therapy "has the potential to be utilized for both early and late therapeutic interventions, as well as for prophylaxis." 

Today's news understandably provided a nice boost for the biotech stock. But it's important to remember that these were only preclinical results. Sorrento has a long way to go before it can conclusively demonstrate that either STI-2020 or STI-1499 is safe and effective in treating patients with COVID-19.

Now what

The U.S. Food and Drug Administration has already given a green light for Sorrento to begin a phase 1 study evaluating STI-1499 in treating hospitalized COVID-19 patients. But with the promising preclinical data announced today, STI-2020 appears to have an even greater potential for success. Sorrento said it plans to file for FDA approval to begin a phase 1 study of STI-2020 "as soon as possible."