Sales Soar 30x with the Right Indication: This Biotech Revives Regeneron’s Old Drug

“In 2008, on the 20th anniversary of its founding, Regeneron successfully launched its first drug, ARCALYST (rilonacept) injection. As Regeneron’s "firstborn," rilonacept initially had modest sales, bringing in only $13.1 million in 2020. However, starting in 2021, rilonacept's sales surged dramatically, reaching $233.2 million in 2023, and the projected sales for 2024 are expected to hit $405-415 million — more than 30 times its 2020 performance! However, by this time, Regeneron had already transferred the rights to rilonacept to Kiniksa Pharmaceuticals.”

So, how did this biotech manage to breathe new life into an old drug?

Kiniksa Pharmaceuticals is a commercial-stage biopharmaceutical company dedicated to discovering, acquiring, developing, and commercializing therapies for debilitating diseases with high unmet medical needs. Founded in 2015 in Bermuda, with its U.S. subsidiary based in Massachusetts, Kiniksa has since evolved into a global biopharmaceutical company. It boasts an experienced team providing commercialized therapies to patients while advancing a portfolio of pipeline candidates.

Kiniksa Pharmaceuticals

ARCALYST (rilonacept) is a recombinant dimeric fusion protein administered via weekly subcutaneous injection, designed to block the signaling of interleukin-1α (IL-1α) and interleukin-1β (IL-1β). It was developed by Regeneron using their "Traps" fusion protein technology platform, which fuses receptor components to the constant region of an antibody molecule (a technique that also gave rise to the famous EYLEA). Rilonacept was initially approved for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS) in 2008 and later for Deficiency of the IL-1 Receptor Antagonist (DIRA) in 2020. In 2017, Kiniksa Pharmaceuticals acquired the exclusive global rights (excluding the Middle East and North Africa) to develop rilonacept for all indications except oncology and local administration in the ear and eye.

Indication Selection for ARCALYST

After acquiring exclusive rights to ARCALYST (rilonacept), Kiniksa chose to develop it for the treatment of recurrent pericarditis, a painful autoinflammatory cardiovascular disease. It is estimated that around 40,000 patients in the U.S. are currently seeking or receiving treatment for recurrent pericarditis. At present, ARCALYST is the first and only FDA-approved drug for treating recurrent pericarditis.

Pericarditis is the most common pericardial disease in clinical settings. Studies show that 15% to 30% of patients with an initial episode of acute pericarditis will experience recurrence, and approximately 10% of those with recurrent pericarditis may have further relapses. Existing treatments include nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and corticosteroids, but these are all considered off-label uses. Long-term high-dose colchicine treatment can cause gastrointestinal discomfort and neutropenia, while corticosteroids have side effects such as glaucoma, fluid retention, hypertension, mood swings, memory changes, other psychological effects, weight gain, and diabetes.

Given these issues, Kiniksa believes that ARCALYST (rilonacept) could become a critical therapy after NSAIDs or colchicine fail to treat recurrent pericarditis.

IL-1α and IL-1β have been shown to play a key role in inflammatory diseases, initiating potent proinflammatory events by engaging IL-1α and IL-1β receptors. Tissue damage caused by IL-1α and IL-1β in the pericardium stimulates the production of additional IL-1α and IL-1β, thus creating a perpetual pericardial inflammatory cycle.

ARCALYST (rilonacept) was granted FDA breakthrough therapy designation and orphan drug designation in 2019 and 2020, respectively, for treating recurrent pericarditis. In 2021, it received orphan drug designation from the European Commission for treating idiopathic pericarditis. In March 2021, the FDA approved ARCALYST for the treatment of recurrent pericarditis and to reduce the risk of recurrence in adults and children aged 12 and older. This approval was based on the results of a global phase 3 clinical trial called RHAPSODY. The study showed that patients treated with ARCALYST had a 96% reduction in the risk of pericarditis recurrence. By the 16th week of the randomized withdrawal period, 92% of patients in the ARCALYST group reported being pain-free or experiencing only mild pericarditis pain (NRS ≤ 2), compared to 40% in the placebo group.

Commercialization Strategy for ARCALYST

Since the commercial launch of ARCALYST (rilonacept) in April 2021 for the treatment of recurrent pericarditis, Kiniksa has developed a targeted commercialization strategy, vertically integrating multiple key functions. As of the end of 2023, the company’s specialized sales team consisted of approximately 85 representatives, capable of reaching a large number of customers and prescribers. This sales force is further supported by medical affairs, payer teams, and patient services, ensuring broad patient engagement, disease education, and driving scientific understanding of recurrent pericarditis.

Additionally, Kiniksa has implemented an effective marketing strategy aimed at educating prescribers and patients about recurrent pericarditis and raising awareness about ARCALYST (rilonacept) as the first and only approved treatment for the condition. In June 2024, Kiniksa announced its sponsorship of the American Heart Association's initiative for treating recurrent pericarditis, which aims to improve access to expert care and the quality of care for patients through collaborative efforts. In the same month, Kiniksa partnered with National Hockey League Hall of Famer Henrik Lundqvist to raise awareness of the disease. According to Kiniksa's market research, 96% of recurrent pericarditis patients reported being misdiagnosed with other conditions, and each patient experienced an average of 2.7 misdiagnoses before receiving the correct diagnosis.

As the first and only FDA-approved drug for recurrent pericarditis, ARCALYST holds both orphan drug and breakthrough therapy designations. The drug is priced at $22,603 per month in the U.S., but Kiniksa offers a patient assistance program that allows eligible patients to pay as little as $0. ARCALYST is distributed through a select network of distributors across the U.S.

Initially, Kiniksa’s commercialization efforts focused on approximately 14,000 U.S. patients with persistent underlying disease, multiple recurrences, and inadequate response to standard therapies. By Q2 2024, the drug had achieved an 11% penetration rate within this core group (up from 9% at the end of 2023), and the company is aiming to expand to a broader population. By Q2 2024, ARCALYST had been prescribed over 2,300 times for recurrent pericarditis, with a 24% repeat prescription rate, a 90% payer approval rate, and an average total treatment duration of 26 months. Patient adherence was 90%, and 45% of patients who initially discontinued treatment (around 8 weeks) returned to ARCALYST for further treatment.

Kiniksa is responsible for the U.S. sales and distribution of ARCALYST for all approved indications (CAPS, DIRA, and recurrent pericarditis), sharing profits and licensing revenues with Regeneron after accounting for manufacturing and commercialization costs. In 2022, ARCALYST generated $122.5 million in total sales, growing to $233.2 million in 2023, a 90% increase. In Q1 and Q2 of 2024, the drug posted revenues of $78.9 million and $103.4 million, respectively, with Q2 showing a 90% year-over-year growth and a 31% quarter-over-quarter increase. The total sales for the first half of 2024 reached $182.3 million, and on the day of the Q2 results announcement, Kiniksa’s stock price surged by 23%. As a result, Kiniksa has raised its 2024 full-year sales forecast for ARCALYST to $405–415 million.

In-Development Product Pipeline of Kiniksa Pharmaceuticals

Kiniksa's product pipeline is built on strong biological foundations or validated mechanisms, targeting a range of cardiovascular and autoimmune diseases with unmet medical needs. The company is focused on offering differentiated potential solutions to these conditions.

Abiprubart is an investigational anti-CD40 monoclonal antibody developed by Kiniksa. It inhibits the co-stimulatory interaction between CD40 and CD154, which is crucial for T-cell signaling, B-cell maturation, immunoglobulin class switching, and type 1 immune responses. The disruption of CD40-CD154 interactions is viewed as a potential approach to treating various autoimmune diseases. In 2019, Kiniksa acquired the intellectual property for Abiprubart from Primatope Therapeutics and secured an exclusive global license for the drug from Beth Israel Deaconess Medical Center (BIDMC).

In December 2021, Kiniksa initiated a phase 2 clinical trial of Abiprubart for treating rheumatoid arthritis (RA), aiming to assess its pharmacokinetics, safety, and efficacy when administered subcutaneously. In January 2024, Kiniksa announced that cohort 3 in the trial achieved its primary efficacy endpoint with weekly dosing. Further data from cohort 4 released in April 2024 confirmed the biological activity of the drug. Kiniksa also announced plans to proceed with a phase 2b trial for Sjögren’s Disease, enrolling around 201 patients to evaluate the therapeutic response to biweekly and monthly subcutaneous doses. Patient recruitment began in July 2024.

Sjögren’s Disease is a chronic autoimmune condition characterized by immune-mediated damage to the salivary and tear glands, along with arthritis, kidney, and lung dysfunction. It affects approximately 250,000 to 300,000 people in the U.S., and there are currently no FDA-approved therapies. External studies have indicated that inhibiting the CD40-CD154 interaction could be an effective treatment approach. Abiprubart’s demonstrated biological activity, favorable pharmacokinetic profile, and convenient subcutaneous formulation hold promise for providing meaningful and differentiated benefits to patients.

Mavrilimumab

Mavrilimumab is an investigational monoclonal antibody targeting the granulocyte-macrophage colony-stimulating factor receptor alpha (GM-CSFRα). Originally developed in collaboration between CSL and MedImmune (now part of AstraZeneca), Kiniksa acquired the global rights to Mavrilimumab from MedImmune in 2017. While the company previously conducted clinical trials of Mavrilimumab for giant cell arteritis (GCA) and COVID-19-related acute respiratory distress syndrome (ARDS), these programs have since been discontinued. Kiniksa is currently exploring potential partnerships to advance further development of Mavrilimumab.

Vixarelimab (formerly KPL-716)

Vixarelimab is a monoclonal antibody that targets the oncostatin M receptor beta (OSMRβ), inhibiting the signaling of both interleukin-31 (IL-31) and oncostatin M (OSM), two key cytokines involved in inflammation, itching, and fibrosis. Kiniksa initially licensed the drug from Biogen in 2016. In August 2022, Kiniksa announced a global licensing agreement with Genentech, a subsidiary of Roche, for the development of Vixarelimab. Under this agreement, Kiniksa received $100 million in upfront and near-term payments and is eligible for up to $600 million in milestone payments. Genentech is currently developing Vixarelimab for the treatment of nodular prurigo and ulcerative colitis.

ARCALYST (Rilonacept) in China by Huadong Medicine

In 2018, ARCALYST (Rilonacept) was included in the first batch of the "List of Clinically Urgent Overseas New Drugs" in China, specifically for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS).

In February 2022, Kiniksa Pharmaceuticals granted Huadong Medicine exclusive rights to develop and commercialize ARCALYST in the Asia-Pacific region, excluding Japan. (Huadong Medicine also acquired Kiniksa’s investigational GM-CSFRα antibody, Mavrilimumab, with an upfront payment of $22 million for both drugs and potential milestone payments reaching up to $640 million.)

In January 2023, ARCALYST was accepted for priority review by the Center for Drug Evaluation (CDE) for the treatment of CAPS in adults and children aged 12 years and older, including Familial Cold Autoinflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS).

According to PharmCloud data (www.pharnexcloud.com), Huadong Medicine submitted two new drug applications for ARCALYST: one for the treatment of CAPS in adults and children aged 12 and older in November 2023, and another for the treatment of recurrent pericarditis in March 2024. Both applications have been accepted by the National Medical Products Administration (NMPA).

2023 Financial Performance and Key Developments

In 2023, Kiniksa reported total revenue of $270.3 million, representing a 23% year-over-year increase. This includes $233.2 million (+90%) in product revenue from ARCALYST (Rilonacept) and $37.08 million in licensing and collaboration revenue. The company's full-year research and development (R&D) expenses totaled $76.1 million, reflecting a 16% increase from the previous year. Selling, general, and administrative (S,G&A) expenses amounted to $129.4 million, up 32% year-over-year.

2023 Full-Year Financial Performance

The distribution of R&D expenditure in 2023 is as follows:

distribution of R&D expenditure in 2023

In the first half of 2024, Kiniksa reported total revenue of $188.5 million, including $182.3 million in product revenue from ARCALYST and $6.21 million in licensing and collaboration revenue. The company's R&D expenses for the first half of the year were $50.35 million, while S,G&A expenses amounted to $81.08 million.

first half of 2024

The distribution of R&D expenses in the first half 2024 is as follows:

In June 2024, Kiniksa signed a contract worth 211.47 billion South Korean won (approximately $156.64 million) with Samsung Biologics. The contract is set to run from June 21, 2024, to December 31, 2031, and covers the manufacturing of key biologics. As of June 30, 2024, Kiniksa held $218.8 million in cash, cash equivalents, and short-term investments. As of August 7, 2024, Kiniksa's total market capitalization was approximately $1.73 billion. At the time of this writing, the company's market capitalization has risen to $1.871 billion, with a share price of $26.26.

Reference

https://www.kiniksa.com/；

https://www.globenewswire.com/news-release/2022/08/03/2491232/0/en/Kiniksa-Pharmaceuticals-Announces-Global-License-Agreement-with-Genentech-for-Vixarelimab.html；

https://www.globenewswire.com/news-release/2022/02/22/2389213/0/en/Kiniksa-Pharmaceuticals-and-Huadong-Medicine-Announce-Strategic-Collaboration.html；

https://www.businesskorea.co.kr/news/articleView.html?idxno=219955；