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.
Recurrent Pericarditis Opportunity
Moat said 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 If therapy is withdrawn while underlying disease remains active, symptoms can return.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 increase as IL-1 signaling resumes. Patients may then restart treatment if needed.
Commercial Education Efforts
Moat said patient access to ARCALYST has been strong and that commercial patients often have zero co-pays. He said Kiniksa has not disclosed the size of its sales force but is deploying commercial and medical-affairs resources across a broad range of treatment settings.
The company has also launched a targeted direct-to-consumer campaign intended to improve patient awareness. Moat said only about 14% of recurrent pericarditis patients surveyed were aware of ARCALYST without prompting, but approximately 80% of patients who discussed the treatment with a healthcare professional ultimately received a prescription.
Recurrent pericarditis patients are treated across academic, rural and other care settings, rather than primarily at established centers of excellence, Moat said. The 40,000-patient population sees about 25,000 healthcare professionals annually. As of the end of the second quarter, about 5,000 healthcare professionals had prescribed ARCALYST at some point over the past five years, he said.
KPL-387 Enters Phase 3
Kiniksa has initiated enrollment and dosing in the Phase 3 portion of its KPL-387 development program. The company is targeting a potential once-monthly autoinjector formulation for the IL-1 alpha and beta inhibitor and expects a potential market entry in the 2028 to 2029 timeframe, subject to clinical data.
Paolini said the company combined Phase 2 and Phase 3 development activities into a single program. In the recently reported Phase 2 dose-finding portion, KPL-387 demonstrated a median time to treatment response of four days and maintained response through the monthly dosing interval, according to Paolini.
The Phase 3 study, called PASTEURAL, is a randomized-withdrawal outcomes trial designed to evaluate time to first pericarditis recurrence and the reduction in recurrence risk in a placebo-controlled setting. Paolini said Kiniksa believes the trial could support registration if successful.
Moat said it is too early to determine how KPL-387 would ultimately be positioned relative to ARCALYST. However, he said that additional efficacious, well-tolerated treatment options could expand use of IL-1 alpha and beta inhibition in recurrent pericarditis.
About Kiniksa Pharmaceuticals International (NASDAQ:KNSA)
Kiniksa Pharmaceuticals International, Inc is a biopharmaceutical company focused on discovering, acquiring and developing therapeutics for patients suffering from lifethreatening and debilitating immune-mediated diseases. Founded in 2013 and headquartered in Lexington, Massachusetts, Kiniksa applies a patient-centric approach to build a diversified portfolio of marketed medicines and clinical-stage candidates targeting inflammation and immunology. The company’s core mission is to address complex conditions with significant unmet medical needs by advancing both novel and differentiated therapies.
The company’s lead marketed product is Ilaris (canakinumab), an interleukin-1β blocker licensed for the treatment of cryopyrin-associated periodic syndromes, systemic juvenile idiopathic arthritis, adult-onset Still’s disease and Schnitzler syndrome.
