Sorrento Therapeutics Plans to Cut Development of Its Coronavirus Vaccine if the Leaders' Vaccines Work

Sorrento Therapeutics (SRNE.Q) is considerably behind Pfizer (PFE 0.23%), BioNTech (BNTX 0.55%), Moderna (MRNA 3.28%), and the rest of the leaders in the race to develop a coronavirus vaccine. While multiple vaccines have completed phase 3 clinical trials or will in the coming months, Sorrento's lead vaccine, T-VIVA-19, hasn't even entered clinical trials yet.

In this video from Motley Fool Live recorded on Nov. 12, Henry Ji, chairman, president, and CEO of Sorrento, talks about the potential advantages of the biotech's vaccine. But given how far behind Sorrento is, he admits the company is watching the leaders and might stop development if it's clear there won't be room for latecomers.

Brian Orelli: You do have a vaccine that you're working on called T-VIVA-19. How does that work, and then what are the advantages of that over the current late-stage vaccines that are being tested right now?

Henry Ji: The late-stage vaccine, firstly, they use all the wild-type virus. Right now, the world already moved on to dominating mutant strains. That means the current vaccine may or may not work. So that means we need the viral antigen design to be meeting with all of the variants first. Secondly, current vaccine mostly is a messenger RNA. We have three different company using the messenger RNA. The manufacturing to be in large quantity is very difficult for messenger RNA, not very stable, and the [...] logistic is going to be [...] Then because there's so many people has the adenovirus infection, the adenovirus-type approach potentially have a safety issue. You already hear the couple of adenovirus being halted a little bit time because some of the severe side effect. Now, our approach is using the protein. It's simple. If you can make the right antigen, the protein is very easy to manufacture in large quantity, firstly. Secondly, the protein is stable at the very cold, let's say, refrigerated state, or you can dry it up, so room temperature is stable too, large quantity. Now, the key here is, how do you design an antigen such that it can avoiding the similar sequence that the virus shares with the human sequence? For example, the virus shares certain sequence homology with the interferon genes, which is very dangerous. That means you cannot create auto-antibody against the interferon. They also have founded out that the virus create also antibody against the ACE-2 receptor.

So you want to avoiding all these potential pitfall in the viral sequence. You have to design it firstly. Secondly, virus protein starting mutating and you need to make sure the virus antigen is exactly the same antigen for the variant and not only the wild-type. You may want to design both the wild-type or the mutant type so that your vaccine stay effective. So what we're doing is we design the viral protein according to the latest information available, and you purify the protein and the vaccination, see what happens. One of the approach we're doing is using the Fc, which is Fc for the antibody, and that binds to the immune cell like the antigen-presenting cells. We use that protein with antigen-presenting Fc. So it combines to antigen receptor, that's the key, to present the antigen receptor to elicit a strongest immune response. We have approach called S1-Fc or RBD RBM Fc that utilize the immune system in your body to elicit strongest immune system. So our approach is protein-based to take care of the other mutant antigens of the virus and to elicit the immune response by properly presenting antigen-presenting cells. But we're designing very carefully because we're already late in this phase and many people are already in phase 3. So that does not bother us because if we have a better design, if you showed better safety and efficacy, you may win the race at the end of it. If we don't, if everybody else's are good, we congratulate them. But we have neutralizing antibody which could be a treatment strategy to complement with their vaccine strategy.

Brian Orelli: When do you think you'll be able to get the vaccine into clinical trials?

Henry Ji: We're still designing the vaccine and we're still testing the animal. If that works, you're talking about a couple of months, couple [...] is reasonable, but we're not in a rush to put anything out there if we're not comfortable with the design and the early animal testing results.

Brian Orelli: So assuming you get something that you're comfortable with, do you think it's going to be difficult to recruit for a large, pivotal clinical trial, 20-30,000 people if there's already multiple vaccines on the market? I think personally, I wouldn't be interested in going into a clinical trial where there's a 50-50 chance I get a placebo if I can be guaranteed of getting a vaccine by taking the product that's on the market.

Henry Ji: Exactly. Brian, if the current vaccine works, of course, we're not going to pursue the vaccine approach because that's a total waste of time. Just in case the current vaccine is outdated, like a flu vaccine, last year's flu vaccine may not work this year, if the current vaccine everybody working on near to EUA approval is outdated, then we have a shot. If it's recurrently, yearly type of vaccine, [NOISE] we might take a shot. The reason is our vaccine is easy to produce as a protein form, easy to transport, and easy administration like intramuscular injections, it's very simple. So it's all depending on what's going on with other vaccine, and nobody knows what the safety profile going to be for all of the vaccine. Some of these things could be 90% effective. What if the safety issues kicks in? You always want to have a backup plan, and if everything goes well, we don't need to be in the game for vaccine. But if nothing works, we could be the one in the game.