New analyses of the MIRROR randomized controlled trial in uncontrolled gout presented at the 2023 EULAR European Congress of Rheumatology

Presentations are part of expert discussions at the EULAR European Congress of Rheumatology, May 31 - June 3, 2023, in Milan.

Data presented from Horizon’s MIRROR randomized controlled trial (RCT), which evaluated Krystexxa in combination with methotrexate for uncontrolled gout, provide further evidence of the impact of therapy on patient-reported outcomes (PROs), urate depletion and bone remodeling.

“Uncontrolled gout is far more painful and dangerous than most people know,” said Brian LaMoreaux, M.D., M.S., senior medical director, Horizon. “This disease can erode joints and bones, impact vital organs and contribute to serious health conditions. What is demonstrated in the new data from the MIRROR RCT is that by sustaining a reduced serum urate level it is possible to deliver progressive meaningful improvements.”

Key Krystexxa Presentations: PROs and gout-related clinical measures captured in the MIRROR RCT included changes from baseline to week 52 in Health Assessment Questionnaire (HAQ) indices (Disability Index, Pain and Health), Physician Global Assessment of Gout (PhGA), and tender or swollen joint counts (TJC/SJC). All quality-of-life measures and gout-related clinical measures progressively improved during treatment and TJC/SJC markedly declined. Participants who received Krystexxa with methotrexate experienced greater improvements in HAQ-Pain and HAQ-Health scores after 52 weeks of therapy than those who received Krystexxa with placebo, potentially because of the higher urate-lowering response rate seen with the co-therapy approach. Quality of life and clinical gout assessment changes in uncontrolled gout patients undergoing pegloticase therapy as part of the MIRROR randomized controlled trial (POS0513).

The MIRROR RCT used dual-energy computed tomography (DECT) imaging to visualize monosodium urate (MSU) crystal deposits, which have been shown to be associated with gout-related bone erosions. Analyses of DECT findings showed rapid and near-complete depletion of MSU crystal deposits within one year of initiating Krystexxa treatment (94% volume reduction in nine imaged regions of six patients who received Krystexxa with methotrexate; 90% volume reductions in five imaged regions of two patients who received Krystexxa with placebo). Imaging findings also indicated that bone remodeling may be possible following depletion of MSU deposits. Evidence of bone remodeling was seen in 69% (29/42) of evaluated erosions (9/12 imaged regions). Of the 29 erosions with remodeling, all had a decrease in size (mean 7% volume reduction change at week 52), with new bone formation also observed in some erosions. Bone erosion remodeling after depletion of monosodium urate deposition with intensive urate-lowering with pegloticase in patients with uncontrolled gout: MIRROR RCT dual-energy CT findings (POS0514).