FDA Approves Pegloticase Plus Methotrexate for Uncontrolled Gout

Today, the US Food and Drug Administration (FDA) approved the co-treatment of pegloticase (Krystexxa) injection plus methotrexate (MTX) for patients with uncontrolled gout.

Pegloticase is a recombinant uricase enzyme that converts urate into water-soluble liquid, allantoin, that can then be easily excreted from the body.

Results from the MIRROR study, a phase 4 randomized, placebo-controlled clinical trial, showed that 71% of patients who received the combination therapy of pegloticase and methotrexate achieved a complete response over 6 months. This was compared with 38.5% in the group of patients who received pegloticase plus placebo.

“Uncontrolled gout carries serious, long-term consequences in the joints and throughout the body, as well as a significant impact on a person’s daily life,” John K Botson, MD, said in a statement. “Through multiple in-practice case series, the open-label trial and the randomized controlled trial, the medical community has been actively engaged in finding ways to reduce the impact of uncontrolled gout by maximizing the use of KRYSTEXXA."

Botson, is one of the co-primary investigators of the study, the president of Alaska Rheumatology Alliance, and a rheumatologist at Orthopedic Physicians Alaska.

The phase 4 trial evaluated the impact on patients with uncontrolled gout when they were administered the combination therapy over a shorter infusion duration each month. This study also included patients who were incomplete responders to pegloticase monotherapy.

The primary endpoint was the proportion of treatment responders at month 6. This included serum uric acid (sUA) of less than 6 mg/dL for at least 80% of the time when patients were evaluated at weeks 20-24. Patients were excluded if they had contraindication to methotrexate, use of immunosuppressants, glucose-6-phosphate dehydrogenase deficiency, and renal impairment.

In March, the FDA granted priority review of Horizon Therapeutics’ Supplemental Biologics License Application (sBLA) for this treatment, with July 7, 2022 as the anticipated Prescription Drug User Fee Act (PDUFA) action date. The decision was based on data presented last month at the European Alliance of Associations for Rheumatology (EULAR) Congress.

"The expanded labeling reflects robust data on this treatment approach," Botson continued, "which can allow us to change outcomes for many uncontrolled gout patients, most of whom have no other treatment option."