Arthrosi to Present Additional Positive Phase 2 Program Data for AR882 at the 26th Asia-Pacific League of Associations for Rheumatology Congress (APLAR)

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Aug 23, 2024, 08:00 ET

—AR882 demonstrated safe and efficacious long-term reduction of serum urate (sUA) levels and elimination of urate crystal deposition in a sub-analysis of gout patients from the Asia-Pacific region—

SAN DIEGO, Calif., Aug. 23, 2024 /PRNewswire/ -- Arthrosi Therapeutics, Inc., a late-stage biotechnology company developing a potentially best-in-class, highly potent and selective next generation URAT1 inhibitor to reduce serum urate levels, flares and tophi in patients with gout, today announced additional positive data from a sub-population analysis for its Phase 2 clinical program in gout patients from the Asia-Pacific region. These data are being presented as a poster at the 26^th Asia-Pacific League of Associations for Rheumatology Congress, being held August 21-25 in Suntec, Singapore.

"We are excited to present new sub-population data from our previously reported positive Phase 2 clinical program for AR882 at APLAR as there remains a significant unmet need for patients suffering from gout worldwide," said Robert T. Keenan, MD, MPH, MBA, Chief Medical Officer at Arthrosi Therapeutics. "The data to be showcased further reinforces AR882's potential to drive robust, durable sUA and tophi reduction, while achieving an improved safety profile compared to existing standard of care to date. Most notably, 83% of patients who received 75mg of AR882 achieved serum urate levels below 5 mg/dL, which is essential for resolving debilitating tophi, crystal burden and flares. We look forward to continuing to evaluate AR882 in our pivotal Phase 3 REDUCE 2 study, initiated in June, and we expect to initiate a second confirmatory Phase 3 study in the second half of this year."

Clinical Data for AR882, Arthrosi's URAT1 Inhibitor

In a poster presentation, Dr. Keenan will highlight sub-group data from the company's Phase 2 program that demonstrates that long-term administration of AR882 is safe and efficacious in reducing sUA and eliminating urate crystal deposition in 68 gout patients from Australia, New Zealand and Taiwan. 53 of these patients were enrolled in the Phase 2 gout study and randomized equally into three treatment groups to receive once-daily AR882 50 mg, AR882 75 mg, or placebo for 3 months. The other 15 patients were enrolled in the Phase 2b subcutaneous tophi study and received once-daily AR882 75 mg, AR882 50 mg in combination with allopurinol 300 mg for 12 months, or allopurinol 300 mg for 6 months then in combination with AR882 75 mg for 6 months. Serum urate levels were measured at 3, 6 and 12-month visits. In the subcutaneous tophi study, caliper measurements and dual energy computed tomography (DECT) were performed at baseline, months 6 and 12. Safety assessments were collected throughout the study.

The data showed:

AR882 75 mg and the AR882 50 mg + allopurinol groups demonstrated a substantial and durable decrease in sUA through 3, 6 and 12 months.
- The pooled mean baseline sUA level was 8.7 mg/dL. At the 3-month visit, median sUA levels were 4.9 and 3.4 mg/dL for AR882 50 mg and AR882 75 mg, respectively, corresponding to a 43.3% and 63.7% reduction.
- 92% and 83% of the patients achieved sUA < 6 and <5 mg/dL, respectively, when taking AR882 75 mg as a monotherapy.
Patients receiving AR882 monotherapy or AR882 in combination with allopurinol showed greater sUA response than allopurinol alone.
DECT urate crystal volume was reduced by 50% in the AR882 75 mg group after 6 months of treatment versus 25% in the allopurinol group.
AR882 was well tolerated. The most frequently reported adverse event was gout flare, which appeared less often in AR882 groups compared to controls.

Details for the poster presentation is as follows:

Title: Efficacy of AR882, a Selective Uric Acid Transporter 1 (URAT1) inhibitor in Gout Patients from the Asia-Pacific Region in Two Phase 2 Studies
Presenting Author: Robert Keenan, M.D., Chief Medical Officer of Arthrosi Therapeutics
Poster Number: 597
Date/Time: Friday, August 23 at 10:45-11:10am and 4:15-4:45pm SGT

The poster presentation will be available in the "Publications" section of Arthrosi's website: https://arthrosi.com/publications/.

About the AR882-202 Phase 2b Study

The Phase 2b study was a global, multicenter, 12-week, randomized, double-blind, placebo-controlled study of 140 gout patients who met the gout classification according to the American College of Rheumatology (ACR) and The European Alliance of Associations for Rheumatology (EULAR). The mean baseline serum urate (sUA) among the participants was 8.6 mg/dL. Patients who participated in the study had several major comorbidities, including hypertension (47%), hyperlipidemia (35%), renal insufficiency (34%), arthritis (23%), diabetes (19%), cardiovascular disease (15%), lung disease (11%), and liver disease (5%). In the study, patients received a daily dose of 50 mg AR882, 75 mg AR882, or matching placebo. The sUA levels (< 6, <5, <4, or <3 mg/dL) were evaluated following 12 weeks of dosing, and safety and tolerability were assessed throughout the study.

About the AR882-203 Phase 2 Study

The Phase 2 study of AR882 in patients with tophaceous gout was a six-month, 1:1:1 randomized, global, placebo-controlled study of 42 patients with subcutaneous tophi. The mean baseline sUA among the participants ranged between 9.1-9.6 mg/dL. In the study, patients received a once daily dose of either 75 mg AR882, 50mg AR882 + allopurinol, or allopurinol up to 300mg. Serum uric acid levels (< 6, <5, <4, or <3 mg/dL) were evaluated monthly through month 6, and safety and tolerability were assessed throughout the study. Tophi measurements with calipers were completed every 4 weeks for 6 months. Patients were also imaged using Dual-Energy Computed Tomography (DECT), DECT a specialized imaging technique that is able to differentiate and identify uric acid crystals in the joints and soft tissue, allowing for quantifying uric acid crystals and tophi at baseline and 6 months. The primary efficacy endpoint was sUA change at 3 months. Secondary endpoints included complete resolution of at least one target tophus with no new tophi and no tophus showing progression. Safety assessments, including vital signs and electrocardiograms, were collected throughout the study. The trial also included a 6-month extension period designed to evaluate longer-term patient outcomes.

About Gout:

In the U.S., an estimated 13 million individuals are diagnosed with gout. Gout is a form of inflammatory arthritis that can significantly diminish mobility, functionality, and overall quality of life. Gout emerges from the crystallization of uric acid within the joints and soft tissue, instigating painful flare-ups and chronic symptoms. The kidneys play a pivotal role in the process, as they are responsible for filtering out and excreting uric acid from the body. In over 90% of gout patients, underexcretion of uric acid results in the imbalanced and elevated sUA levels that can lead to the deposition of uric acid crystals. It's essential to monitor and manage sUA levels as part of comprehensive gout treatment and prevention strategies.

About Arthrosi:

Arthrosi Therapeutics, Inc., headquartered in San Diego, CA, is focused on developing AR882, a potentially best-in-class, highly potent and selective next generation URAT1 inhibitor to reduce serum urate levels, flares and tophi in patients with gout. Gout remains a large and growing market with ~ 13M patients in the U.S. alone, ~2M of which have tophaceous gout. AR882 has demonstrated encouraging efficacy and safety compared to SOC in Phase 2 studies as well as impressive results in achieving complete resolution of tophi in a Phase 2b study. Arthrosi is currently advancing AR882 in a pivotal Phase 3 program.

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SOURCE Arthrosi Therapeutics