MIRROR open-label study of Krystexxa shows response in gout.- Horizon Therapeutics

Horizon Therapeutics announced topline results from its MIRROR open-label study in which methotrexate with Krystexxa (pegloticase injection) provided an increased durability of response for people living with chronic gout refractory to conventional therapies – also known as uncontrolled gout. Data from the Methotrexate to Increase Response Rates in Patients With Uncontrolled GOut Receiving Krystexxa (MIRROR OL) shows that 79 percent, or 11 of 14 patients, achieved a complete response, defined as the proportion of serum uric acid (sUA) responders (sUA < 6 mg/dL) at Month 6. Detailed results from the study will be presented at a future medical meeting. The co-prescription of Krystexxa and methotrexate is investigational and its safety and efficacy have not been established. Krystexxa has demonstrated rapid reduction in sUA levels for people with uncontrolled gout; however, treatment with biologic medicines can, in some, trigger the body’s immune system to develop anti-drug antibodies. These anti-drug antibodies can reduce the effectiveness of the biologic therapy. Immunomodulators such as methotrexate, which is commonly used by rheumatologists, can help reduce this reaction. The MIRROR open-label pilot study follows other studies that showed an improved response rate when Krystexxa is co-administered with methotrexate. This includes an independent case series presented at the Annual European Congress of Rheumatology meeting in June 2019 in which the administration of Krystexxa with methotrexate resulted in a 100 percent response (10 of 10 patients) as defined by greater than 80 percent of sUA levels being maintained at goal (<6.0 mg dl) during the treatment period. further, a separate case series presented at the american college of rheumatology meeting in november 2019 resulted in an 80 percent response (8 of 10 patients) as defined by receiving at least 12 infusions without loss of sua response.>