1. Alexion Pharmaceuticals for rare inflammatory diseases, but on a smaller scale.

2. A specialized biotech company akin to Vertex Pharmaceuticals, focused on autoimmune and inflammatory rare diseases.

• ARCALYST (rilonacept): An interleukin-1 (IL-1) blocker approved for treating recurrent pericarditis, Cryopyrin-Associated Periodic Syndromes (CAPS), and Deficiency of IL-1 Receptor Antagonist (DIRA).
• Vixarelimab: A fully human monoclonal antibody in clinical development designed to inhibit oncostatin M (OSM) for the potential treatment of prurigo nodularis and other inflammatory diseases.
• KPL-404: A monoclonal antibody in clinical development that targets the CD40 ligand (CD40L) for the potential treatment of various autoimmune diseases.

• Specialty Distributors: These companies handle the distribution of complex, high-cost, and often temperature-sensitive pharmaceutical products like those developed by Kiniksa. They serve as intermediaries between the pharmaceutical manufacturer and the dispensing pharmacies or healthcare providers.
• Specialty Pharmacies: These pharmacies focus on dispensing and managing specialty medications, which often require special handling, administration, and patient education. They provide comprehensive support to patients taking these complex drugs.

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The ongoing Phase 3 clinical development of AbbVie's Rinvoq (upadacitinib) for Giant Cell Arteritis (GCA) presents a clear emerging threat. Rinvoq is an oral JAK inhibitor that, if approved, would compete directly in a market that Kiniksa is targeting with its investigational anti-GM-CSF receptor antibody, mavrilimumab. The potential approval of a highly effective oral therapy like Rinvoq could significantly impact the market potential and commercial viability of mavrilimumab in GCA.

Kiniksa Pharmaceuticals International (KNSA) focuses on developing and commercializing therapeutic medicines for debilitating diseases with significant unmet medical needs. Their main products and pipeline candidates, along with their addressable markets, are as follows:

• ARCALYST (rilonacept): Approved for recurrent pericarditis, Cryopyrin-Associated Periodic Syndromes (CAPS), and Deficiency of the Interleukin-1 Receptor Antagonist (DIRA) in the U.S..
  • For **recurrent pericarditis**, the target addressable market in the U.S. is estimated to be 14,000 multiple-recurrence patients.
  • The global recurrent pericarditis market is estimated to be valued at approximately USD 585.63 billion in 2025 and is projected to reach USD 851.90 billion by 2032, growing at a compound annual growth rate (CAGR) of 5.5% from 2025 to 2032.
  • The pericarditis drugs market (which includes recurrent pericarditis) in the U.S. reached USD 1.8 billion in 2024. The global pericarditis market size was estimated at USD 2.32 billion in 2024 and is expected to grow to USD 3.37 billion in 2029, at a CAGR of 7.9%. The recurrent pericarditis segment specifically is anticipated to grow at a CAGR of 6.6%.
• KPL-387 (investigational): This is an investigational human immunoglobulin G2 monoclonal antibody in a Phase 2/3 clinical trial for advanced recurrent pericarditis. KPL-387 is intended to further expand the IL-1 inhibition market for recurrent pericarditis.
• Mavrilimumab (previously in pipeline): While mavrilimumab was previously in development for Giant Cell Arteritis (GCA), Kiniksa has discontinued its development for this indication.
  • For **Giant Cell Arteritis**, the estimated U.S. prevalence is approximately 75,000 – 150,000 patients.
  • The global Giant Cell Arteritis Therapeutics Market was valued at approximately USD 1.14 billion in 2024 and is projected to reach nearly USD 1.82 billion by 2032, with a CAGR of 6% from 2025 to 2032.
  • Across the top 7 markets (US, EU4, UK, and Japan), the giant cell arteritis market reached USD 1,180.4 million in 2024 and is expected to reach USD 1,945.5 million by 2035.
• Vixarelimab (licensed out): Kiniksa has entered a global license agreement with Roche and Genentech for the development and commercialization of vixarelimab.
  • It was being evaluated for **prurigo nodularis**, a chronic inflammatory skin condition with an estimated U.S. prevalence of approximately 300,000 patients.
• KPL-404 (investigational): In Phase 2 clinical trials for **rheumatoid arthritis**.
  • The broader global tumor necrosis factor (TNF) inhibitor drugs market, which includes treatments for rheumatoid arthritis, was valued at USD 41.3 billion in 2023 and is projected to reach USD 51.55 billion by 2034, growing at a CAGR of 1.86% from 2025 to 2034. North America holds the largest share of this market.

Kiniksa Pharmaceuticals International (KNSA) is anticipated to experience future revenue growth over the next 2-3 years, driven by several key factors:

1. Continued Expansion of ARCALYST Market Penetration: The primary driver for Kiniksa's near-term revenue growth is the ongoing expansion of ARCALYST's (rilonacept) market penetration for recurrent pericarditis. The company has consistently raised its 2025 net sales guidance for ARCALYST, projecting it to be between $670 million and $675 million. This growth is fueled by an increasing number of active commercial patients, a growing prescriber base, and a longer average duration of therapy. As of late 2024/mid-2025, only approximately 13-15% of the estimated 14,000 multiple-recurrence patients were on ARCALYST therapy, indicating significant room for further adoption.

2. Favorable Evolution of Treatment Guidelines for Recurrent Pericarditis: There is a notable shift in clinical guidelines towards earlier and more frequent use of IL-1 pathway inhibition, which ARCALYST addresses, as a steroid-sparing approach for recurrent pericarditis. This evolving standard of care supports broader and earlier adoption of ARCALYST, contributing to sustained revenue momentum.

3. Potential Commercialization of KPL-387 in Recurrent Pericarditis: Kiniksa's pipeline asset, KPL-387, which has received Orphan Drug Designation from the FDA for pericarditis, is expected to be a significant future growth driver. KPL-387 aims to offer an improved dosing regimen with a target profile of monthly subcutaneous injection in a liquid formulation, potentially enhancing patient convenience and further expanding the recurrent pericarditis market. Data from its Phase 2 dose-focusing trial is anticipated in the second half of 2026. Additionally, KPL-387 and KPL-1161 (another next-generation IL-1 monoclonal antibody) are wholly owned by Kiniksa, meaning the company would retain all profits, unlike ARCALYST, which is subject to profit-sharing.

4. Advancement of Other Pipeline Assets: Beyond ARCALYST and KPL-387, Kiniksa's broader pipeline, including KPL-1161 for recurrent pericarditis (with a target of quarterly dosing) and Vixarelimab for prurigo nodularis (currently in Phase 2b clinical trials), represents opportunities for revenue diversification. Successful development and potential commercialization of these assets would reduce reliance on a single product and provide additional revenue streams in the mid to long term.

[2] Share Issuance

• In July 2020, Kiniksa Pharmaceuticals priced a public offering of 5,952,381 Class A common shares at $21.00 per share.
• Concurrently in July 2020, the company conducted a private placement of 1,428,572 Class A1 common shares.
• The gross proceeds from both the public offering and concurrent private placement were approximately $155.0 million.

[4] Outbound Investments

• In February 2025, Kiniksa announced the discontinuation of the development of abiprubart in Sjögren's Disease, signaling a reallocation of capital.
• Also in February 2025, the company terminated its exclusive license agreement for mavrilimumab with MedImmune.

[5] Capital Expenditures

• For the last 12 months as of November 7, 2025, capital expenditures were approximately -$1.13 million.
• Kiniksa expects to remain cash flow positive on an annual basis and continue investing across its business, including commercialization and pipeline advancement.