Arthrosi Shares Positive Phase 2 Data for AR882 at EULAR 2024

Arthrosi Therapeutics, Inc., a late-stage biotechnology company based in San Diego, has announced promising new clinical findings from its Phase 2 AR882-203 study. The study focuses on patients with tophaceous gout, a severe form of gout characterized by chronic pain and reduced functionality. These findings were presented at the European Congress of Rheumatology (EULAR) 2024, held in Vienna, Austria.

Dr. Robert T. Keenan, the Chief Medical Officer of Arthrosi, noted the positive outcomes of the study. According to Dr. Keenan, the data from the 12-month trial underline the long-term effectiveness and safety of AR882, reinforcing its potential as a best-in-class treatment for gout. The study results demonstrated a substantial and sustained reduction in serum urate (sUA) levels and a significant decrease in tophus and crystal volumes over the 12-month period.

The Phase 2 trial was conducted globally and included 42 patients, each with at least one subcutaneous tophus. Participants were divided into three groups: one receiving 75 mg of AR882 daily, another receiving a combination of 50 mg AR882 and allopurinol, and a third group receiving up to 300 mg of allopurinol alone. After six months, the allopurinol-only group began receiving 75 mg of AR882, while the other groups continued their respective treatments.

Key findings from the study include:
- Persistent and sustained sUA reduction across all groups over the 12-month period.
- Initial baseline sUA levels ranged between 9.1-9.6 mg/dL across the groups. By the third month, median sUA levels dropped to 4.5 mg/dL in the AR882 75 mg group, 4.7 mg/dL in the AR882 50 mg + allopurinol group, and 6.1 mg/dL in the allopurinol group. By the 12th month, sUA levels further dropped to 3.9 mg/dL, 4.4 mg/dL, and 4.0 mg/dL, respectively.
- Complete resolution of at least one target tophus was observed in 35.7% of patients in the AR882 75 mg group and 36.4% in the combined AR882 75 mg + allopurinol group.
- Significant reductions in total urate crystal volumes were observed: -7.5 cm3 and -10.6 cm3 in the AR882 75 mg and combination groups, respectively, over the first six months. This reduction continued to -13.3 cm3 for AR882 75 mg monotherapy by the 12th month. For patients with a baseline crystal volume of ≥5.0 cm3, the reduction was a notable -26.4 cm3 at 12 months.
- AR882 was well-tolerated both as a standalone treatment and in combination with allopurinol over the 12 months.

Additionally, another poster presented by Litain Yeh, Ph.D., the CEO of Arthrosi, discussed the drug-drug interaction (DDI) data for AR882. In vitro studies revealed no significant interactions with key renal, hepatic, and gastrointestinal transporters, except for a slight inhibition of the breast cancer resistance protein (BCRP). Clinical studies further confirmed no relevant alterations in the pharmacokinetics of sulfasalazine, a commonly used drug in treating autoimmune and rheumatic diseases, when co-administered with AR882.

The ongoing promising results from Arthrosi Therapeutics’ Phase 2 trials underscore the potential of AR882 as a transformative treatment for patients suffering from gout. The company aims to advance AR882 into Phase 3 trials, with the hope of offering a superior option for managing and alleviating the symptoms of gout.