Kiniksa Pharma Hits All-Time High as ARCALYST Revenue Nears Blockbuster Status; KNSA Up 120% YTD

Kiniksa Pharmaceuticals (KNSA) shares touched an all-time intraday high of $98.36 on Oct. 29, the latest milestone in a rally driven by strong sales growth of its lead drug ARCALYST. The stock has gained more than 120% year-to-date and closed at $97.56, up 282% from the $25.53 price when RTTNews first highlighted it on April 29, 2025. ARCALYST net product revenue reached $286.0 million in the third quarter of 2026, representing approximately 58% year-over-year growth. This follows quarterly increases of 56% in Q1 2026 ($214.3 million) and roughly 55% in Q2 2026 ($243.6 million), prompting the company to raise its full-year 2026 revenue outlook multiple times. Full-year 2026 ARCALYST net sales are projected to reach $1.045 billion to $1.050 billion, which would mark blockbuster status for the first time. Key upcoming catalysts include a year-end 2026 Phase 1 trial of KPL-1161 and a second-half 2027 data readout from the pivotal Phase 3 PASTORALE trial of KPL-387 in recurrent pericarditis.