ARCALYST approaching $1B/year funds KPL-387's pivotal pericarditis trial; Phase 3 data will determine whether Kiniksa owns the category it created

Kiniksa is a commercial-stage pharmaceutical company with an approved drug for recurrent pericarditis and a second candidate in pivotal trials for the same disease, not yet approved.

Kiniksa built a rare profitable commercial engine in recurrent pericarditis, with ARCALYST on track for roughly $990M in 2026 revenue and 21% patient penetration still leaving meaningful upside. KPL-387, a next-generation quarterly-dosed IL-1 inhibitor, met its Phase 2 primary endpoint and is now in a pivotal Phase 3 randomized withdrawal trial; the thesis resolves on whether that trial replicates the efficacy signal with a clean placebo-controlled design. The primary risk is that a single-arm-adjacent randomized withdrawal design in a small orphan population may generate noisy data, and Ventyx's VTX2735 is enrolling in the same indication on a potentially overlapping timeline.