KNSA Stock: Insider Activity, Filings & Research

Kiniksa Pharmaceuticals, Ltd. (KNSA) — Drillr’s hub for KNSA insider activity, SEC filings, earnings signals and AI research. Over the trailing 3 months, KNSA insiders filed 0 open-market buys and 16 sales (SEC Form 4).

Sentiment

0/100

Buys (3m)

Sells (3m)

Net (3m)

-$34.5M

Insider trades by month Buys Sells

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Context3-month price +1.2%Institutions mixed (13F)

Date	Insider	Type	Shares	Price
Jun 2, 2026	Levy Richard Sdirector	Grant	2,026	—
Jun 2, 2026	McCain Tracey Ldirector	Option	2,799	—
Jun 2, 2026	Popovits Kimberly Jdirector	Grant	12,158	$48.38
Jun 2, 2026	Cole G Bradleydirector	Option	2,799	—
Jun 2, 2026	Malley Thomasdirector	Grant	12,158	$48.38
Jun 2, 2026	BAKER BROS. ADVISORS LPdirector	Grant	36,474	$48.38
Jun 2, 2026	Quart Barry Ddirector	Option	2,799	—
Jun 2, 2026	Levy Richard Sdirector	Grant	12,158	$48.38
Jun 2, 2026	BAKER BROS. ADVISORS LPdirector	Grant	6,078	—
Jun 2, 2026	Malley Thomasdirector	Grant	2,026	—
Jun 2, 2026	Cole G Bradleydirector	Grant	2,026	—
Jun 2, 2026	Malley Thomasdirector	Option	2,799	—
Jun 2, 2026	Popovits Kimberly Jdirector	Option	2,799	—
Jun 2, 2026	Cole G Bradleydirector	Grant	12,158	$48.38
Jun 2, 2026	Quart Barry Ddirector	Grant	2,026	—

Source: KNSA SEC Form 4 filings, latest Jun 2, 2026. For informational purposes only — not investment advice.

Overview

Kiniksa Pharmaceuticals, Ltd. (NASDAQ:KNSA) is a biopharmaceutical company founded in 2015 and based in Hamilton, Bermuda. The company went public in May 2018 and focuses on developing and commercializing therapeutic medicines for patients with debilitating diseases that have significant unmet medical needs. Kiniksa has successfully transitioned from a development-stage company to a profitable commercial enterprise, primarily driven by the success of its flagship product ARCALYST for treating recurrent pericarditis, a rare inflammatory cardiovascular condition.

Business

Kiniksa operates in the specialized biopharmaceutical sector, focusing on rare inflammatory and autoimmune diseases. The company's core business revolves around interleukin-1 (IL-1) pathway inhibition, a therapeutic approach that targets specific inflammatory proteins responsible for various disease conditions. The company's primary commercial product is ARCALYST (rilonacept), which represents approximately 95% of total revenue. ARCALYST is an IL-1 blocker administered as a weekly subcutaneous injection for treating recurrent pericarditis. Pericarditis is an inflammatory condition affecting the protective sac around the heart, and when it recurs multiple times, it becomes a chronic, debilitating condition. Before ARCALYST's approval, patients typically relied on anti-inflammatory drugs like colchicine and corticosteroids, which often provided inadequate relief and came with significant side effects. The company's pipeline includes several development-stage assets targeting different inflammatory conditions: 1. KPL-387 - A next-generation IL-1 receptor antagonist being developed as a monthly subcutaneous injection for recurrent pericarditis, potentially offering improved patient convenience compared to weekly ARCALYST dosing. 2. Abiprubart (formerly mavrilimumab) - A monoclonal antibody that was previously in development for Sjögren's disease but has been discontinued in favor of focusing resources on other opportunities. 3. Vixarelimab - A monoclonal antibody in Phase 2a clinical trials for prurigo nodularis, a chronic inflammatory skin condition. 4. KPL-404 - A monoclonal antibody targeting the CD40-CD154 interaction, which plays a role in immune system regulation.

Revenue model

Kiniksa generates revenue primarily through direct product sales of ARCALYST to specialty pharmacies and healthcare providers. The company operates under a traditional pharmaceutical business model where it sells its approved drug at premium prices justified by the significant unmet medical need and limited treatment alternatives. The company's customers are primarily cardiologists and rheumatologists who treat patients with recurrent pericarditis. With over 3,150 unique prescribers as of Q1 2025, Kiniksa has successfully penetrated approximately 11% of the estimated 14,000 patients with multiple recurrence pericarditis in the United States. The average treatment duration is approximately 30 months, creating a substantial recurring revenue stream from each patient. ARCALYST's pricing power stems from several factors. The drug addresses a serious medical condition with limited alternatives, resulting in payer approval rates exceeding 90%. Insurance coverage is generally favorable due to the drug's clinical efficacy and the high medical costs associated with untreated recurrent pericarditis, including emergency room visits and hospitalizations. Several factors could impact Kiniksa's margins positively or negatively. Positive margin drivers include the company's ability to expand into earlier stages of disease (currently 15% of prescriptions are for first recurrence versus 85% for multiple recurrences), increased treatment duration as physicians gain confidence in long-term therapy, and operational leverage as the sales force becomes more productive. Negative margin pressures could arise from increased competition if new IL-1 inhibitors enter the market, potential pricing pressure from payers as the market matures, and the substantial investment required for pipeline development and clinical trials. The company benefits from relatively predictable revenue due to the chronic nature of recurrent pericarditis and high patient compliance rates exceeding 85%. However, the business remains dependent on a single product, creating concentration risk until the pipeline matures.

Competitive moat

Kiniksa's competitive moat is moderately strong but narrow, primarily built around its first-mover advantage in the recurrent pericarditis market and specialized expertise in IL-1 pathway therapeutics. The company's moat consists of several key elements: Regulatory barriers provide the strongest protection, as ARCALYST is the only FDA-approved treatment specifically for recurrent pericarditis. This regulatory exclusivity, combined with the complexity and cost of conducting clinical trials in rare diseases, creates significant barriers for potential competitors. The company has built substantial clinical evidence and real-world data demonstrating ARCALYST's efficacy and safety profile. Market knowledge and relationships represent another defensive element. Kiniksa has invested heavily in educating physicians about recurrent pericarditis as a treatable chronic condition rather than an acute episodic illness. The company has established relationships with over 3,150 prescribers and built a specialized sales force with deep expertise in this therapeutic area. However, the moat faces several potential threats. Large pharmaceutical companies with existing IL-1 inhibitors, such as Novartis with canakinumab (Ilaris), could potentially seek approval for recurrent pericarditis, leveraging their broader resources and established anti-inflammatory franchises. Biosimilar competition could emerge as ARCALYST's patents expire, though the specialized nature of the indication may limit this risk. The company is attempting to strengthen its moat by developing KPL-387, a next-generation monthly formulation that could offer improved patient convenience and potentially better efficacy. Additionally, expanding the pipeline into adjacent inflammatory conditions could diversify the revenue base and leverage the company's IL-1 expertise across multiple indications. Overall, while Kiniksa enjoys a strong position in its niche market, the moat is primarily dependent on regulatory protection and could be vulnerable to well-resourced competitors with complementary anti-inflammatory portfolios.

Risks & safety

Kiniksa demonstrates a strong margin of safety with solid financial fundamentals and minimal solvency risk, though valuation metrics suggest limited upside at current levels. • Liquidity and Solvency: Cash position of $157 million as of Q1 2025, current ratio of 3.66, and minimal debt (debt-to-equity ratio of 0.02). The company generates positive operating cash flow ($22.3 million in Q1 2025) and expects to remain cash flow positive annually. • Valuation Metrics: Trading at 47.2x trailing P/E ratio, which appears elevated for a single-product company. EV/EBITDA of 27.6x reflects premium valuation. Price-to-book ratio of 3.53x indicates shares trade well above tangible book value. • Other Considerations: Revenue growth remains strong (75% year-over-year in Q1 2025) with raised guidance suggesting continued momentum. However, dependence on single product creates concentration risk. Pipeline development requires continued investment with uncertain outcomes.

Recent development

Over the past few years, Kiniksa has executed a successful transition from development-stage biotech to profitable commercial company. The most significant development has been the dramatic commercial expansion of ARCALYST, with net product revenue growing from $122.5 million in 2022 to $417 million in 2024, representing a compound annual growth rate of approximately 85%. The company has strategically expanded its commercial reach by growing the sales force to 85 representatives and increasing the prescriber base from approximately 800 physicians in 2022 to over 3,150 by Q1 2025. Kiniksa has also invested heavily in disease awareness campaigns, including the "Life DisRPted" initiative and partnerships with celebrities like former NHL goalie Henrik Lundqvist to raise awareness about recurrent pericarditis. A key strategic pivot has been the development of KPL-387, announced in late 2024 as a next-generation IL-1 receptor antagonist designed for monthly subcutaneous administration. This represents a significant investment in extending the company's leadership in recurrent pericarditis treatment, with potential launch targeted for 2028-2029. The monthly dosing could provide a competitive advantage over the current weekly ARCALYST regimen. The company has also made strategic decisions to focus its pipeline, discontinuing development of abiprubart in Sjögren's disease to concentrate resources on higher-probability opportunities. This disciplined approach to capital allocation reflects management's focus on maximizing return on investment in clinical development. Additionally, Kiniksa has expanded treatment paradigms by promoting ARCALYST use in earlier stages of disease, with approximately 15% of current prescriptions now for first recurrence patients compared to primarily multiple-recurrence patients in earlier years. This expansion represents a significant market opportunity as it potentially doubles the addressable patient population.

KNSA company profile · for informational purposes only — not investment advice.

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