Gilead Sciences has filed for approval of JAK1 inhibitor filgotinib in Japan. The submission moves Gilead a step closer to selling the Galapagos-partnered drug to rheumatoid arthritis patients in the country.
Filgotinib has passed a series of milestones in 2019, starting with the delivery of phase 3 data in March and continuing on to recent regulatory events. Gilead emerged from a meeting with the FDA this summer confident it will file for approval in the U.S. by the end of 2019. The strategy is more advanced in Europe, where regulators are already reviewing a filing for approval.
Now, Gilead has filed for approval in Japan. The filing, like its European counterpart, is based on data from a phase 3 rheumatoid arthritis program that tested filgotinib in multiple contexts against several comparators including AbbVie’s aging blockbuster Humira.
The data suggest filgotinib is better at inducing clinical remission than Humira and likely competitive against rival JAK inhibitors and other rheumatoid arthritis treatments. Whether that is enough to turn filgotinib into a big product for Gilead remains to be seen.
Filgotinib faces the prospect of being the fourth JAK inhibitor to come to market in Japan. However, Gilead and Galapagos think filgotinib has the credentials to be a come-from-behind success in Japan and Western markets, where it faces competition from the same drugs.
The pitch for filgotinib rests partly on safety data. Pfizer's Xeljanz and Eli Lilly's Olumiant, the first JAK inhibitors to come to market, are encumbered by black box warnings. Zeroing in on JAK1 was floated as a way to avoid the problems associated with Xeljanz and Olumiant, both of which also hit JAK2, but AbbVie’s Rinvoq still ended up with a black box warning when the FDA cleared it earlier this year.
The FDA hit Rinvoq with the warning despite clinical trial data suggesting the molecule has a cleaner safety profile than Xeljanz and Olumiant. Gilead and Galapagos argue filgotinib is safer still, but it could be tarred with the same brush as Xeljanz and Olumiant if the FDA thinks there is a classwide issue.