Sorrento Therapeutics' (SRNE.Q -16.67%) COVI-MSC seems likes promising therapy for COVID-19 after the first four patients treated with the stem cell therapy were released from the hospital. But in this video from Motley Fool Live, recorded on Feb. 1, Fool.com contributors Brian Orelli and Keith Speights discuss why investors shouldn't read too much into the initial uncontrolled results.

Brian Orelli: Sorrento Therapeutics has a stem cell product called COVI-MSC, that's the codename. It's treating COVID-19 induced acute respiratory distress or acute respiratory distress syndrome. Basically, people with lung problems with COVID-19 they've had four patients so far treated and they've all been released from the hospital. Shares around like 14% today off the fourth patient. They've released the first three earlier in the week and it also jumped. It seems like good news, but there's no control. There's no really way to know whether they would've gotten better on their own.

Keith Speights: Yeah, it's not a randomized study, no control group. I saw a tweet, I can't remember who tweeted it, but this morning someone said; you know, Sorrento is going to have a press release every time somebody gets out of the hospital. [laughs] Yeah, we're only talking about four patients. This is really early. Hey, it's promising. It could pan out and be very, very good. It's just way too early to know.

Orelli: Yes, without a control group there's just no way to know where those patients would have gotten better. This isn't cancer, so if you see 4 out of 4 people responded to cancer treatment, you know it must have been the drug that worked because cancer patients don't get better on their own. But these people are being treated in the hospital with a whole bunch of other treatments including oxygen and whatever so they can fight off the virus on their own and there's no way to know whether it's actually the drug that helped them get better.