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Why Did the FDA Reject Rigel's EUA Application for Its COVID-19 Therapy?

By Keith Speights and Brian Orelli, PhD – Aug 26, 2021 at 7:31AM

Key Points

  • The FDA recently refused to grant an EUA for Rigel's Tavalisse in treating COVID-19.
  • Rigel's EUA submission was based on phase 2 results; the FDA wants more data from a phase 3 study.

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More data is needed.

Not every COVID-19 vaccine or therapy wins Emergency Use Authorization (EUA). Rigel Pharmaceuticals (RIGL -1.57%) recently received a thumbs-down from the Food and Drug Administration for an EUA filing for its COVID therapeutic candidate. In this Motley Fool Live video recorded on Aug. 18, 2021, Motley Fool contributors Keith Speights and Brian Orelli discuss why the FDA turned down an EUA for Rigel's experimental COVID therapy.

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Keith Speights: Let's switch to a non-COVID-19 story. Actually, this is a COVID-19 story, but it's not a vaccine story. The FDA turned down Emergency Use Authorization for Rigel Pharmaceuticals' experimental COVID-19 therapy, even though the company reported positive results from a phase 2 study.

Brian, why did the FDA hand down this rejection to Rigel?

Brian Orelli: Yeah. This was only from a phase 2 study, and the study was just in 59 patients. It seems like that just wasn't enough for the FDA, especially at this late in the pandemic. Maybe if they had the data and they were the first drug to try to get Emergency Use Authorization, then maybe that would be enough.

When all the hospitals convert completely full, but at this point the FDA seems like they want some more data on the company's running a phase 3 clinical trial. The drug's already approved as second line treatment for thrombocytopenia. It goes by the brand name Tavalisse, T-A-V-A-L-I-S-S-E. The company expects to complete enrollment in that clinical trial by the end of this year. Then the NIH [National Institutes of Health] is also studying the drug in a platform of phase 3 study and that just started.

So the data for that trial will be a while. But I think it's disappointing for the company because they could've had sales if the FDA would have approved based on the phase 2 data. Now they're going to have to wait until the phase 3, and by the time they get the phase 3 data, and then submit the Emergency Use Authorization.

Now, hopefully more and more people have been vaccinated, and therefore the number of people that need treatment will have gone down substantially. Unfortunately, I think they've missed a lot of their potential for this drug, at least as COVID-19 treatment. They still have it as thrombocytopenia treatment.

Speights: Alright. The company, Rigel's CEO, Raul Rodriguez, said that if the phase 3 study meets its endpoints, the company does plan to resubmit it's EUA filing with the additional data.

I think there's a bigger story here. I think a lot of people may have been skeptical about the FDA's EUA process, that hey, they're cutting corners, that the agency is just rushing through the process and putting vaccines and therapies on the market that haven't really been scrutinized heavily. I think this is at least one example that shows no, that's not the case. The FDA is really looking at the data, and if the data doesn't support the safety and efficacy of a vaccine or a therapy for COVID-19, it's not going to get an EUA, and I think that's what we're seeing here.

Orelli: Yeah. Early on I think there was a lot more pressure for them to give Emergency Use Authorizations. But I think now with less people needing it and already having treatments on the market, I think that puts pressure on the latecomers to produce more data than the early comers did.

Keith Speights has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.

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