Kiniksa Pharma can do no wrong.

Arcalyst is crushing its wide-open opportunity in recurrent pericarditis. The asset raked in first-quarter revenue of $214 million, while management now expects full-year sales of at least $930 million. Revenue guidance has been increased almost every quarter for the last two years though.

Although collaboration expenses (the portion of gross profit split with Regeneron) is eating up precious cash flow, the business continues to generate cash and ended March 2026 with $468 million in greenbacks. Of course, wouldn't it be nice to not owe any money to Regeneron?

That's the hope of the wholly-owned pipeline led by KPL-387, a next-generation asset with an almost identical mechanism of action to Arcalyst. Kiniksa expects to share data from a phase 2 study exploring multiple doses and dose frequencies in 2H 2026. It might be the only thing that can clip this bird's wings.

Whereas Arcalyst is dosed every week, KPL-387 might be dosed once monthly (every four weeks). That's the hope. The phase 2 study is evaluating two separate dose levels every two weeks and two separate dose levels every four weeks. Will the market throw a temper tantrum if either monthly dosing option isn't good enough to advance into the planned phase 3 study?