Kiniksa Highlights ARCALYST Growth as KPL-387 Advances Into Phase 3

Kiniksa reported approximately $243 million in second-quarter net revenue, up $29 million from the prior quarter, marking its largest quarterly increase since the treatment launched. The company remains profitable and expects to stay cash-flow positive annually. ARCALYST had reached 21% penetration among recurrent pericarditis patients with at least two recurrences, while Kiniksa is expanding awareness and use across the broader estimated 40,000-patient market. KPL-387 has entered Phase 3 testing as a potential once-monthly autoinjector for recurrent pericarditis, with a possible market launch in 2028–2029 if successful. The PASTEURAL trial will assess recurrence timing and risk reduction versus placebo. Kiniksa Pharmaceuticals International NASDAQ: KNSA said its commercialized recurrent pericarditis treatment ARCALYST continues to grow, while the company has begun a pivotal Phase 3 study of follow-on candidate KPL-387. Speaking at a Canaccord Genuity event, Chief Operating Officer Ross Moat said Kiniksa reported approximately $243 million in net revenue during the second quarter, representing $29 million in quarter-over-quarter growth. He described the increase as the company’s largest quarterly growth since ARCALYST launched more than five years ago. ARCALYST is an interleukin-1 alpha and beta inhibitor approved for recurrent pericarditis, a disease involving inflammation of the sac surrounding the heart. Moat said Kiniksa is profitable, well capitalized and expects to remain cash-flow positive on an annual basis. Approximately 160,000 patients experience pericarditis in a given year, with about 40,000 of those patients developing recurrent pericarditis. He characterized the condition as severe and debilitating, adding that patients can face delays in diagnosis and an average of 2.7 misdiagnoses before receiving a recurrent pericarditis diagnosis. Historically, patients were generally treated with NSAIDs and colchicine before progressing to corticosteroids, according to Moat. However, treatment practices have changed following ARCALYST’s introduction, with clinical guidance supporting use of interleukin-1 alpha and beta inhibition after NSAIDs and colchicine and before corticosteroids, he said. Kiniksa has disclosed a 21% penetration rate, as of the end of the second quarter, among the approximately 14,000 recurrent pericarditis patients who have had two or more recurrences. Moat said the company is also seeing increased use among the roughly 26,000 patients experiencing a first recurrence. The ARCALYST label does not require a specified number of prior flares, Moat noted. He said the company is focused on the full 40,000-patient population and that physicians have become more comfortable prescribing and managing patients on a biologic therapy. Patients have remained on ARCALYST for an average of about three years, according to Moat. He said published natural-history data suggest that the median duration of disease among patients with two or more recurrences is around three years, although some patients continue to experience disease for substantially longer periods. Chief Medical Officer John Paolini said ARCALYST suppresses the IL-1 pathway and disease activity while patients remain on treatment. If therapy is withdrawn while underlying disease remains active, symptoms can return. He said trial data indicated that, after treatment is stopped, the drug takes roughly six weeks to wash out, followed by a period during which chest pain can gradually increa...