The U.S. Food and Drug Administration recently announced that it's requiring a warning about potential health issues linked to JAK inhibitors. The agency is also restricting the use of the drugs to patients who were unsuccessfully treated with at least one TNF inhibitor.

This decision especially hurts AbbVie (NYSE:ABBV). The big pharma company was counting on JAK inhibitor Rinvoq to deliver strong sales growth. In this Motley Fool Live video recorded on Sept. 8, Motley Fool contributors Keith Speights and Brian Orelli discuss how the FDA decision that's causing pain for AbbVie should help Sanofi (NASDAQ:SNY) and Regeneron (NASDAQ:REGN).

Keith Speights: Now this FDA decision to restrict JAK inhibitors to treat rheumatoid arthritis only for patients who failed on a TNF blocker especially hurt AbbVie. But where there are losers, there are also usually winners. Which companies do you think benefited the most from the FDA's JAK inhibitor decision?

Brian Orelli: I think Sanofi and Regeneron seems like the biggest winner. It has Dupixent. The drug doesn't necessarily have as good of efficacy as some other JAK inhibitors for eczema, and Pfizer's second-generation JAK inhibitor, Abrocitinib, beat Dupixent recently in a head-to-head study, but it clearly has a better safety profile than the JAK inhibitors as a class.

I think the safety is going to keep doctors using Dupixent before the JAK inhibitors, and maybe they'll reserve the JAK inhibitors for patients who aren't helped by other drugs.

Speights: I think you're right. I think Sanofi and Regeneron are the clear winners here. Dupixent is already a big commercial success story for those companies. I think it picks up even more sales as a result of this FDA decision.

Orelli: Yeah. It's also used in asthma as well, I believe, and so it has the sales for that, too, which obviously, it won't benefit from the JAK there, but definitely, in eczema, I think it'll pick up some sales compared to JAK inhibitors.

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