Sorrento Therapeutics (NSDQ: SRNE), a San Diego-China biotech, reported that its anti-SARS-CoV-2 antibody, STI-1499, completely inhibited SARS-CoV-2 virus infection from interacting with the ACE2 receptor after four days of incubation. In preclinical studies, the molecule was effective at a very low antibody concentration. The company discovered STI-1499 by screening its proprietary G-MAB™ fully human antibody library. One week ago, Sorrento announced it would develop a three-molecule "protective shield" against SARS-CoV-2 with Mt. Sinai Hospital. STI-1499 will be part of that therapy, though Sorrento will also develop the candidate as a stand-alone product.

The three-antibody cocktail would provide additional protection against mutations, Sorrento said.

According to Sorrento, its screening G-MAB™ fully human antibody library discovered hundreds of antibody candidates that bind the S1 subunit of the SARS-CoV-2 Spike protein. Approximately one dozen of these also blocked the S1 protein's interaction with human angiotensin-converting enzyme 2 (ACE2), the receptor used for viral entrance into human cells.

When these antibodies were tested for their ability to inhibit SARS-CoV-2 virus infection in an in vitro SARS-CoV-2 virus infection model, STI-1499;s ability to block 100% of the virus made it stand out.

Sorrento revealed plans to move development of STI-1499 forward as quickly as possible. The company will request priority evaluation and accelerated review from regulators to speed development. Sorrento says its existing state-of-the-art cGMP antibody manufacturing facility in San Diego will produce up to two hundred thousand doses per month, though the company will ramp up production to a million doses even before any FDA approvals.

Although it is willing to risk its own capital in the effort, Sorrento is also seeking potential government support and pharmaceutical partners to scale STI-1499 manufacturing capacity up to tens of millions of doses.

In an interview with Biospace (see story), Sorrento pointed out that STI-1499 is not a vaccine: "“The difference between an antibody and a vaccine is that a vaccine takes either a protein from the virus, or—some of them aren’t real vaccines, but people are calling them vaccines—where DNA or RNA is being injected into patients’ arms and making material in the patient that the patient’s immune system responds to,” said Mark Brunswick, Vice President of Regulatory Affairs, Sorrento.

Brunswick continued: "The problem with that is not every patient will respond to a vaccine. Some will have 10% efficacy, some will have 20% efficacy, some will have 90% efficacy. But until you’ve gone into large trials and assessed everyone, you won’t know the full extent a vaccine works. An antibody gives instantaneous protection against the virus.”

“The elderly or an immunocompromised person will have a lack of immune response to a vaccine, but the antibody should provide the instant immunity,” added Henry Ji, PhD, co-founder, director, president and CEO of Sorrento. "Our STI-1499 antibody shows exceptional therapeutic potential and could potentially save lives following receipt of necessary regulatory approvals. We at Sorrento are working day and night to complete the steps necessary to get this product candidate approved and available to the waiting public," Dr. Ji, said.

Headquartered in San Diego, Sorrento has operations in Nanjing and a manufacturing subsidiary in Suzhou. It has had a dual focus on novel biologic products for cancer and other medications to treat pain. The company has immuno-oncology platforms, including key assets such as fully human antibodies (the G-MAB™ library), clinical stage immuno-cellular therapies (CAR-T, DAR-T), antibody-drug conjugates, and a clinical stage oncolytic virus (Seprehvir®).

Sorrento has been an active deal maker, but with only one commercial product, the company has often faced a cash crutch. It raised $150 million in private equity from a consortium led by Ally Bridge in 2016, but it had to fight off a $933 million take-private offer earlier this year.

The welcome SAR-CoV-2 news lit a considerable fire under the company's stock price. It climbed 150%, rising $3.95 to $6.97, a market cap for Sorrento of $1.4 billion.

In 2018, Sorrento had five separate manufacturing facilities: Judicial Facilities (San Diego, CA) for CAR-T therapies and antibody production, Providence Facilities (RI) for CAR-T therapies, Camino Santa Fe Facilities (San Diego, CA) for oncolytic virus production, Suzhou Facilities (China) for antibody-drug conjugate (linker toxin synthesis and bio conjugation) production and Bioserv Corporation (San Diego, CA) for small molecule and biologics fill and finish, medical devices and high potency compound fill and finish.

See our other articles on Sorrento Therapeutics.

Disclosure: none.