Kiniksa Pharmaceuticals International, plc, a biopharmaceutical company, develops and commercializes novel therapies for diseases with unmet need, with a focus on cardiovascular indications.
The company’s portfolio of assets is based on strong biologic rationale, or validated mechanisms, and offers the potential for differentiation.
RCALYST is an interleukin-1a (IL-1a) and interleukin-1ß (IL-1ß) cytokine trap. In 2017, the company licensed ARCALYST from Regeneron, which discovered and initiall...
Kiniksa Pharmaceuticals International, plc, a biopharmaceutical company, develops and commercializes novel therapies for diseases with unmet need, with a focus on cardiovascular indications.
The company’s portfolio of assets is based on strong biologic rationale, or validated mechanisms, and offers the potential for differentiation.
RCALYST is an interleukin-1a (IL-1a) and interleukin-1ß (IL-1ß) cytokine trap. In 2017, the company licensed ARCALYST from Regeneron, which discovered and initially developed the drug. The company’s exclusive license to ARCALYST from Regeneron includes worldwide rights, excluding the Middle East and North Africa, for all applications other than those in oncology and local administration to the eye or ear.
The company received FDA approval of ARCALYST for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years and older in March 2021. Recurrent pericarditis is a painful inflammatory cardiovascular disease, with an estimated United States prevalent population of approximately 40,000 patients seeking and receiving medical treatment. ARCALYST is also approved in the United States for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Autoinflammatory Syndrome (FCAS) and Muckle-Wells Syndrome in adults and children 12 years and older, and the maintenance of remission in Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adults and children weighing 10 kg or more.
ARCALYST is commercially available across the United States through a select network of specialty pharmacies. The company is responsible for sales and distribution of ARCALYST in all approved indications in the United States and evenly splits profits on sales, as well as third-party proceeds, with Regeneron. In 2022, the company granted Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. (Huadong) exclusive rights to develop and commercialize ARCALYST in the Huadong Territory. In 2023, Regeneron initiated a technology transfer of the manufacturing process for ARCALYST drug substance, and the company is working to qualify Samsung as its replacement CDMO.
KPL-387 is an investigational, fully human immunoglobulin G2 monoclonal antibody that binds human interleukin-1 receptor 1 (IL-1R1), inhibiting IL-1a- and IL-1ß-mediated signaling.
In June 2024, the company initiated a Phase 1 clinical trial of KPL-387 in normal healthy volunteers. In February 2025, the company announced its plan to initiate a Phase 2/3 clinical trial of KPL-387 in recurrent pericarditis in mid-2025.
KPL-1161 is an independently developed, pre-clinical, Fc-modified immunoglobulin G2 monoclonal antibody that binds IL-1R1, inhibiting IL-1a- and IL-1ß-mediated signaling. KPL-1161 is a modified version of KPL-387 designed to have an increased drug half-life.
Abiprubart is an investigational monoclonal antibody inhibitor of CD40-CD154 costimulatory interaction. The company holds an exclusive worldwide license to abiprubart from Beth Israel Deaconess Medical Center, Inc. (BIDMC).
The company previously announced a Phase 2b clinical trial of abiprubart in Sjögren’s Disease. In February 2025, the company announced its plans to discontinue development of abiprubart in the indication and explore strategic alternatives for the asset.
Mavrilimumab is an investigational monoclonal antibody inhibitor targeting granulocyte-macrophage colony stimulating factor receptor alpha (GM-CSFRa). In 2017, the company licensed exclusive worldwide rights in all indications to mavrilimumab from MedImmune, Limited, which has since been acquired by AstraZeneca PLC (MedImmune). In February 2025, the company announced its termination of its license agreement from MedImmune for convenience, effective in May 2025. In addition, in February 2025, the company provided written notice to Huadong that Huadong has not conducted material development activity with respect to mavrilimumab in the People’s Republic of China for a continuous period in excess of six months, as required under the mavrilimumab Huadong Collaboration Agreement.
Unless Huadong conducts material development activity within 60 days of the notice, the mavrilimumab Huadong Collaboration Agreement will terminate in April 2025.
Using a data-centric approach, the company’s team considers a wide variety of metrics to drive informed capital allocation strategies and generate value from this pipeline, including by analyzing potential additional indications for its products and product candidates, being opportunistic in its business development activities to in-license or acquire programs, considering appropriate opportunities to partner or out-license its programs, and conducting internal research to discover and develop molecules to expand its portfolio.
Strategy
The core of the company’s strategy is the identification, development, and commercialization of therapeutic medicines for patients suffering from debilitating cardiovascular diseases with significant unmet medical need. The company puts patients first and lives by its motto: Every Second Counts. Critical components of the company’s business strategy include Commercializing ARCALYST; Advancing the company’s Product Candidates Through the Development Process; Exploring Opportunities to Drive Value and Maximize the Potential of the company’s Existing Portfolio; and Working to Identify, Discover, Acquire, and Develop New Therapies.
Products
ARCALYST
ARCALYST is an IL-1a and IL-1ß cytokine trap. ARCALYST is currently approved in the United States for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years and older, the treatment of CAPS, including FCAS and Muckle-Wells Syndrome in adults and children 12 years and older, and the maintenance of remission in DIRA in adults and children weighing 10 kg or more. ARCALYST was sold by Regeneron in the United States for the treatment of CAPS from 2008 and the maintenance of remission in DIRA from 2020 until the company assumed responsibility for sales in such indications in March 2021.
In 2022, the company granted Huadong exclusive rights to develop and commercialize ARCALYST in the Asia Pacific region, excluding Japan.
Clinical Trials
In June 2020, the company reported results from RHAPSODY, its global, double-blind, placebo-controlled, randomized-withdrawal design, pivotal Phase 3 clinical trial of ARCALYST in subjects with recurrent pericarditis. RHAPSODY met its prespecified primary and all major secondary efficacy endpoints with statistical significance.
Commercial Strategy for ARCALYST
Since the company’s commercial launch of ARCALYST for the treatment of recurrent pericarditis in 2021, the company has developed a focused and targeted commercial strategy. The company’s specialty salesforce calls on high-volume accounts and prescribers. The company’s salesforce is complemented by its medical affairs, payor, and patient services teams who work to secure broad patient access to ARCALYST, educate communities, collaborate with patient advocacy groups, and drive scientific understanding of recurrent pericarditis. Further, the company has established an efficient marketing effort intended to educate and raise awareness of recurrent pericarditis among prescribers and patients and promote ARCALYST as the first and only treatment for this debilitating disease.
First, the company is focused on increasing awareness of the disease and its impact on patients’ lives. The company’s sales and marketing teams work to educate patients and prescribers about the signs, symptoms, duration, and treatment of the disease, and the impact that recurrent pericarditis has on patients’ lives. The company has further partnered with each of NHL Hall-of-Famer Henrik Lundqvist and GRAMMY Award-Winning Singer-Songwriter Carly Pearce as part of its Life DisRPted Campaign to drive awareness of recurrent pericarditis.
Second, the company aims to secure broad patient access at a price that reflects ARCALYST’s value as the first and only FDA-approved therapy for recurrent pericarditis. Helping to ensure affordability and access to treatment by patients is one of its core principles. To this end, the company offers a suite of programs to support affordability for eligible patients who are prescribed ARCALYST.
Third, the company has built a robust patient support program to optimize patient experiences with ARCALYST and Kiniksa. The company’s Kiniksa OneConnect program offers personalized treatment support for eligible patients prescribed ARCALYST. This program is designed to ensure patients have a positive experience from initiating ARCALYST therapy through the end of their treatment.
Fourth, the company is working to improve the patient journey for those suffering from recurrent pericarditis. For example, in 2024, the company announced its sponsorship of the American Heart Association’s Addressing Recurrent Pericarditis initiative. This initiative is designed to facilitate knowledge-sharing across a collaborative network of healthcare providers around the United States and streamline patient access to expert care. The participating healthcare sites offer patients dedicated, expert care and aim to shorten patients’ journeys to diagnoses.
Product Candidates
KPL-387
KPL-387 is an investigational, fully human immunoglobulin G2 monoclonal antibody that binds IL1-R1, inhibiting the signaling of both IL-1a and IL-1ß cytokines. In June 2024, the company initiated a Phase 1 clinical trial of KPL-387 in normal healthy volunteers, and data from such study suggests that KPL-387 holds the potential for monthly subcutaneous dosing. In February 2025, the company announced its plan to initiate a Phase 2/3 clinical trial of KPL-387 in recurrent pericarditis in mid-2025.
Phase 2 Clinical Trial
In February 2025, the company announced its plan to initiate a Phase 2/3 clinical trial of KPL-387 in recurrent pericarditis in mid-2025.
KPL-1161
KPL-1161 is an independently developed, pre-clinical, Fc-modified immunoglobulin G2 monoclonal antibody that binds IL-1R1, inhibiting IL-1a- and IL-1ß-mediated signaling. KPL-1161 is a modified version of KPL-387 designed to have an increased drug half-life. The company is conducting pre-clinical development of this asset.
Abiprubart
Abiprubart is an investigational monoclonal antibody inhibitor of CD40-CD154 costimulatory interaction. The company previously announced a Phase 2b clinical trial of abiprubart in Sjögren’s Disease. In February 2025, the company announced its plans to discontinue development of abiprubart in the indication and explore strategic alternatives for the asset. The company previously conducted a proof-of-concept Phase 2 clinical trial of abiprubart in RA.
In July 2024, the company commenced a Phase 2b clinical trial of abiprubart in Sjögren’s Disease. In February 2025, as part of the company’s strategic reprioritization of its portfolio and certain capital allocation considerations, the company announced its plans to discontinue its Phase 2b clinical trial of abiprubart in Sjögren’s Disease.
Mavrilimumab
Mavrilimumab is a fully-human monoclonal antibody that is designed to antagonize GM-CSF signaling by binding to the alpha subunit of the GM-CSF receptor. In February 2025, the company delivered a notice of termination to MedImmune, notifying them of its intent to terminate for convenience the MedImmune Agreement effective May 22, 2025.
In 2022, the company granted Huadong exclusive rights to develop and commercialize mavrilimumab in the Asia Pacific region, excluding Japan. In February 2025, the company provided written notice to Huadong that Huadong has not conducted material development activity with respect to mavrilimumab in the People’s Republic of China for a continuous period in excess of six months, as required under the mavrilimumab Huadong Collaboration Agreement. Unless Huadong conducts material development activity within 60 days of the notice, the mavrilimumab Huadong Collaboration Agreement will terminate in April 2025.
Discovery Activities
The company conducts internal discovery activities directed toward wholly owned molecules for the treatment of debilitating disease targets.
Commercial Operations
The company’s commercial team combines dozens of years of pharmaceutical commercial leadership experience with a passion for helping patients with significant unmet medical need. Since March 2021, the company has marketed ARCALYST, its only commercial product, in the United States for recurrent pericarditis and has established its own specialty salesforce to expand its commercialization efforts nationwide. The company’s salesforce is complemented by its medical affairs, payor, and patient services teams. In 2024, the company launched a number of initiatives intended to increase disease awareness of recurrent pericarditis, including sponsoring the American Heart Association’s Addressing Recurrent Pericarditis initiative and launching its Life DisRPted campaign.
License and Acquisition Agreements
Out-Licensing Agreements
Genentech Agreement
In August 2022, the company entered into a license agreement (the Genentech License Agreement) with Genentech, Inc. and F. Hoffmann-La Roche Ltd. (collectively, Genentech), pursuant to which the company granted Genentech exclusive worldwide rights to develop, manufacture, and commercialize vixarelimab and related antibodies (each, a Genentech Licensed Product). The Genentech License Agreement became effective in September 2022 following termination of the statutory waiting period under the Hart-Scott Rodino Act.
Huadong Collaboration Agreements
In February 2022, the company entered into two collaboration and license agreements (each, a Huadong Collaboration Agreement and together, the Huadong Collaboration Agreements) with Huadong, pursuant to which the company granted Huadong exclusive rights to develop and commercialize ARCALYST and develop, manufacture, and commercialize mavrilimumab (each, a Huadong Licensed Product and together, the Huadong Licensed Products) in the following countries: People’s Republic of China, Hong Kong SAR, Macao SAR, Taiwan Region, South Korea, Indonesia, Singapore, The Philippines, Thailand, Australia, Bangladesh, Bhutan, Brunei, Burma, Cambodia, India, Laos, Malaysia, Maldives, Mongolia, Nepal, New Zealand, Sri Lanka, and Vietnam (collectively, the Huadong Territory). The company otherwise retained its current rights to the Huadong Licensed Products outside the Huadong Territory.
In-Licensing Agreements
License Agreement with Regeneron
In September 2017, the company entered into a license agreement with Regeneron (the Regeneron Agreement). Pursuant to the Regeneron Agreement, the company has an exclusive license under certain intellectual property rights controlled by Regeneron to develop and commercialize ARCALYST worldwide, excluding the Middle East and North Africa, for all indications other than those in oncology and local administration to the eye or ear. Upon receiving positive data in RHAPSODY, the company’s pivotal Phase 3 clinical trial of ARCALYST, Regeneron transferred the biologics license application (BLA) for ARCALYST to the company. In March 2021, when the FDA granted approval of ARCALYST for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years of age and older, the company assumed the sales and distribution of ARCALYST for CAPS and DIRA in the United States.
License Agreement with MedImmune
In December 2017, the company entered into a license agreement with MedImmune (subsequently acquired by AstraZeneca PLC) (the MedImmune Agreement), pursuant to which MedImmune granted the company an exclusive, sublicensable, worldwide license to certain intellectual property rights to make, use, develop, and commercialize mavrilimumab and any other product containing an antibody to the GM-CSF receptor alpha that is covered by certain MedImmune patent rights for all indications. The company also acquired non-exclusive licenses to other MedImmune technology for use in exploiting licensed products. The company also acquired reference rights to relevant manufacturing and regulatory documents, and MedImmune’s existing supply of mavrilimumab drug substance. The company was obligated to use commercially reasonable efforts to develop and commercialize the licensed products.
Biogen Asset Purchase Agreement
In September 2016, the company entered into an asset purchase agreement (the Biogen Agreement) with Biogen MA Inc. (Biogen) to acquire all of Biogen’s right, title, and interest in and to certain assets used in or relating to vixarelimab and other antibodies covered by certain patent rights, including patents and other intellectual property rights, clinical data, certain contracts, know-how, and clinical drug supply (the Acquired Biogen Assets). In addition, Biogen granted the company a non-exclusive, sublicensable, worldwide license to certain background patent rights related to the vixarelimab program. Under the Biogen Agreement, the company is obligated to use commercially reasonable efforts to develop and commercialize the Acquired Biogen Assets.
Beth Israel Deaconess Medical Center License Agreement
In 2019, the company acquired all of the outstanding securities of Primatope Therapeutics, Inc. (Primatope), the company that owned or controlled the intellectual property related to abiprubart. In connection with its acquisition of Primatope, the company acquired the rights to an exclusive license to certain intellectual property rights controlled by BIDMC to make, use, develop, and commercialize abiprubart under the BIDMC license agreement (the BIDMC Agreement).
Intellectual Property
ARCALYST is a registered trademark of Regeneron.
ARCALYST
The company has a field-specific exclusive license under the Regeneron Agreement to granted patents and pending applications in the United States and numerous other jurisdictions relating to ARCALYST. As of December 31, 2024, the patent rights in-licensed under the Regeneron Agreement relating to its program include three granted patents in the United States and a patent granted in Japan. In addition, the patent rights in-licensed under the Regeneron Agreement relating to the company’s program include patent applications that are pending in the United States, Canada, Europe, and selected countries in Asia. A United States patent covering ARCALYST as a composition of matter expired in 2020, and relevant composition of matter patents issued outside of the United States expired in 2023. Four patents covering methods of using ARCALYST in the treatment of recurrent pericarditis have issued in the United States and have a statutory term that expires in 2038, not including any patent term adjustment. In March 2021, the FDA granted approval for ARCALYST for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years of age and older, which granted the company seven years of marketing exclusivity in the United States.
KPL-387
The company owns pending patent applications relating to KPL-387, which cover formulations and methods of manufacturing KPL-387. The company also owns a pending patent application covering methods of using KPL-387 in the treatment of recurrent pericarditis. For example, in the United States, a new biologic product receives 12 years of data exclusivity upon receiving regulatory approval. In the EU, a new product generally receives eight years of data exclusivity and an additional two years of market exclusivity upon regulatory approval.
KPL-1161
The company owns a pending patent application relating to KPL-1161, which covers composition of matter. If issued, patents covering the composition of matter will have statutory expiration dates in 2046, not including any patent term extensions or adjustments.
Abiprubart
The company owns, via its acquisition of Primatope, granted patents and pending patent applications in the United States and numerous other jurisdictions relating to abiprubart. The company also has an exclusive license with BIDMC to granted patents and pending patent applications in the United States and numerous other jurisdictions relating to abiprubart. These patents and patent applications cover abiprubart as a composition of matter and its use. As of December 31, 2024, the patent rights acquired from Primatope include four patents granted in the United States and 32 patents granted in other jurisdictions, including Australia, Brazil, and selected countries in Europe and Asia. In addition, the patent rights acquired from Primatope include patent applications pending in the United States, Australia, Europe, Canada, and selected countries in Asia. The issued composition of matter patents acquired from Primatope have statutory expiration dates in 2036, not including any patent term extensions or adjustments. As of December 31, 2024, the patent rights licensed from BIDMC include two patents granted in the United States and 58 patents granted in other jurisdictions, including Australia, Canada, and selected countries in Europe and Asia. In addition, the patent rights licensed from BIDMC include patent applications pending in the United States, Europe, and Canada. The issued composition of matter patents licensed from BIDMC have statutory expiration dates in 2032, not including any patent term extensions or adjustments. Patent term extension could extend the expiration date of one patent in the United States and patents in certain other jurisdictions, each in accordance with applicable law.
Other Intellectual Property
In addition to the above, the company maintains certain other intellectual property, including patents, trademarks, and know-how, related to its pre-clinical development and broader Kiniksa brand.
Government Regulation
The company, and its contract development and manufacturing organizations (CDMOs), are required to register its establishments with the U.S. Food and Drug Administration (FDA) and certain state agencies. Registration with the FDA subjects the company and its CDMOs to periodic unannounced inspections by the FDA, during which the agency inspects manufacturing facilities to assess compliance with cGMPs. Accordingly, the company and its CDMOs must continue to expend time, money, and effort in the areas of production and quality control to maintain compliance with cGMPs.
The company is subject to federal laws, including the Medicaid Drug Rebate Program (MDRP), that require pharmaceutical manufacturers to report certain calculated product prices to the government or provide certain discounts or rebates to government authorities or private entities, often as a condition of reimbursement under government healthcare programs. The company’s products are eligible to be reimbursed by Medicaid. Medicaid is a joint federal and state program that is administered by the states for low-income and disabled beneficiaries. Under the MDRP, participating manufacturers are required to pay a rebate for each unit of product reimbursed under the state Medicaid programs. The amount of the rebate for each product is set by law and depends in part on the prices at which its products are sold to certain other purchasers and may be subject to an additional discount if certain pricing increases more than inflation.
The company’s business is subject to a number of other regulations that apply broadly to companies doing business in the healthcare space, including the following:
The United States federal Anti-Kickback Statute, which prohibits, among other things, persons from knowingly and willfully soliciting, offering, receiving, or providing remuneration, directly or indirectly, in cash or in kind, to induce or reward either the referral of an individual for, or the purchase, order, or recommendation of, any good or service for which payment may be made under federal and state healthcare programs such as Medicare and Medicaid. A person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation;
The United States federal False Claims Act and civil monetary penalties laws, which, among other things, impose criminal and civil penalties, including through civil whistleblower or qui tam actions, against individuals or entities for knowingly presenting, or causing to be presented, to the federal government, claims for payment that are false or fraudulent or making a false statement to avoid, decrease, or conceal an obligation to pay money to the federal government. Pharmaceutical manufacturers can be held liable under the False Claims Act even when they do not submit claims directly to government payors if they are deemed to ‘cause’ the submission of false or fraudulent claims. Moreover, a claim including items and services resulting from a violation of the federal Anti-Kickback Statute is deemed a false or fraudulent claim for purposes of the False Claims Act;
The United States Foreign Corrupt Practices Act (FCPA), the U.K. Bribery Act 2010 (the Bribery Act), and similar anti-bribery or anti-corruption laws, regulations, or rules in other countries in which the company operates, which prohibit companies and their representatives from paying, offering to pay, promising to pay, or authorizing the payment of anything of value to any foreign government official, government staff member, political party, or political candidate for the purpose of obtaining or retaining business or to otherwise obtain favorable treatment or influence a person working in an official capacity abroad. The Bribery Act may also create liability where the company fails to prevent a person associated with it from committing a bribery offense. In many countries, the healthcare professionals the company interacts with may meet the FCPA’s and Bribery Act’s definition of a foreign government official. The FCPA also requires public companies to make and keep books and records that accurately and fairly reflect their transactions and to devise and maintain an adequate system of internal accounting controls;
The United States federal Health Insurance Portability and Accountability Act, as amended (HIPAA), which imposes criminal and civil liability for executing a scheme to defraud any healthcare benefit program or obtain, by means of false or fraudulent pretenses, representations, or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of the payor (e.g., public or private) and knowingly and willfully falsifying, concealing, or covering up a material fact or making any materially false statement in connection with the delivery of or payment for healthcare benefits, items, or services. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation;
The United States federal physician payment transparency requirements, sometimes referred to as the Sunshine Act, which requires manufacturers of drugs, devices, biologics, and medical supplies that are reimbursable under Medicare, Medicaid, or the Children’s Health Insurance Program to report to the Department of Health and Human Services information related to certain financial interactions with physicians (defined to include medical doctors, dentists, optometrists, podiatrists, and chiropractors), certain non-physician practitioners (including physician assistants and nurse practitioners), and teaching hospitals, as well as the ownership and investment interests of physicians and their immediate family members; and
Similar healthcare laws and regulations in the EU, the United Kingdom, and other jurisdictions, including Directive 2001/83/EC on the Community code relating to medicinal products for human use and its national implementing legislation; the UK Human Medicines Regulations 2012; Directive 2011/83/EU on consumer rights and its national implementing legislation; and reporting requirements detailing interactions with and payments to healthcare professionals, which may be applicable even if the company is not commercializing a product in such jurisdictions.
Research and Development
The company’s research and development expenses were $111.6 million for the year ended December 31, 2024.
History
The company was founded in 2015. It was incorporated under the laws of Bermuda in 2015. The company was formerly known as Kiniksa Pharmaceuticals, Ltd. and changed its name to Kiniksa Pharmaceuticals International, plc in June 2024.
