Arthritis & Rheumatology: Study Compares Gout Treatments with Different Mechanisms of Action – URAT1 Inhibitor vs Xanthine Oxidase Inhibitor

Arthritis & Rheumatology:
Study Compares Gout Treatments with Different Mechanisms of Action – URAT1 Inhibitor vs Xanthine Oxidase Inhibitor

A China study, published in Arthritis & Rheumatology, compared two gout treatments with different mechanisms of action: benzbromarone, a URAT1 inhibitor and febuxostat, a xanthine oxidase inhibitor. The former increases excretion of uric acid and the latter decreases formation of uric acid. Gout is caused when levels of uric acid exceed 7 mg/dL, a condition known as hyperuricemia. Both treatments aim to lower uric acid levels to < 6 mg/dL. The results showed low-dose benzbromarone was more effective in lowering uric acid to < 6mg/dL and the safety profiles of both drugs were similar.

In a 12-week trial, 196 Chinese participants with gout were randomly assigned to low-dose benzbromarone (25 mg daily) or low-dose febuxostat (20 mg daily). The results show a higher percentage of participants in the low-dose benzbromarone group achieved the serum urate target (< 6 mg/dL) compared with the low-dose febuxostat group (61% versus 32%). Furthermore, the incidence of adverse events was similar for both groups with the exception of transaminase elevation in the low-dose febuxostat group (4% for low-dose benzbromarone versus 15% for low-dose febuxostat). Participants taking benzbromarone, a URAT 1 inhibitor which increases the excretion of urate, were equally likely to be affected by gout flares and urolithiasis as those taking febuxostat, a xanthine oxidase inhibitor which decreases the formation of uric acid. It may be possible the occurrence of gout flares and urolithiasis is not directly related to the mechanism of URAT1 inhibitors.

The study is positive news for Atom Therapeutics, whose lead gout treatment, APB-671, is a new generation of the URAT1 inhibitor designed to improve efficacy and significantly reduce adverse events.

Read the Arthritis & Rheumatology publication here