A multicentre, efficacy and safety study of methotrexate to increase response rates in patients with uncontrolled gout receiving pegloticase (MIRROR): 12-month efficacy, safety, immunogenicity, and pharmacokinetic findings during long-term extension of an open-label study.

BACKGROUND: Publications suggest immunomodulation co-therapy improves responder rates in uncontrolled/refractory gout patients undergoing pegloticase treatment. The MIRROR open-label trial showed a 6-month pegloticase + methotrexate co-therapy responder rate of 79%, compared to an established 42% pegloticase monotherapy responder rate. Longer-term efficacy/safety data are presented here. METHODS: Uncontrolled gout patients (serum urate [SU] ≥ 6 mg/dL and SU ≥ 6 mg/dL despite urate-lowering therapy [ULT], ULT intolerance, or functionally-limiting tophi) were included. Patients with immunocompromised status, G6PD deficiency, severe kidney disease, or methotrexate contraindication were excluded. Oral methotrexate (15 mg/week) and folic acid (1 mg/day) were administered 4 weeks before and during pegloticase therapy. Twelve-month responder rate (SU < 6 mg/dL for ≥ 80% during month 12), 52-week change from baseline in SU, and extended safety were examined. Efficacy analyses were performed for patients receiving ≥ 1 pegloticase infusion. Pharmacokinetics (PK)/anti-drug antibodies (ADAs) were examined and related to efficacy/safety findings. RESULTS: Fourteen patients were included (all male, 49.3 ± 8.7 years, 13.8 ± 7.4-year gout history, pre-therapy SU 9.2 ± 2.5 mg/dL). Three patients were non-responders and discontinued study treatment before 24 weeks, one patient exited the study per protocol at 24 weeks (enrolled prior to treatment extension amendment), and 10 remained in the study through week 52. Of the 10, 8 completed 52 weeks of pegloticase + methotrexate and were 12-month responders. The remaining two discontinued pegloticase + methotrexate at week 24 (met treatment goals) and stayed in the study under observation (allopurinol prescribed at physicians' discretion); one remained a responder at 12 months. At 52 weeks, change from baseline in SU was - 8.2 ± 4.1 mg/dL (SU 1.1 ± 2.4 mg/dL, n = 10). Gout flares were common early in treatment but progressively decreased while on therapy (weeks 1-12, 13/14 [92.9%]; weeks 36-52, 2/8 [25.0%]). One patient recovered from sepsis (serious AE). Two non-responders developed high ADA titers; fewer patients had trough concentrations (Cmin) below the quantitation limit (BQL), and the median Cmin was higher (1.03 µg/mL vs. BQL) than pegloticase monotherapy trials. CONCLUSIONS: Pegloticase + methotrexate co-therapy was well-tolerated over 12 months, with sustained SU lowering, progressive gout flare reduction, and no new safety concerns. Antibody/PK findings suggest methotrexate attenuates ADA formation, coincident with higher treatment response rates. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03635957 . Registered on 17 August 2018.

Pegloticase in Combination With Methotrexate in Patients With Uncontrolled Gout: A Multicenter, Open-label Study (MIRROR).

OBJECTIVE: To examine the efficacy and safety of pegloticase in combination with methotrexate (MTX) in patients with uncontrolled gout in an exploratory, open-label clinical trial (ClinicalTrials.gov: NCT03635957) prior to a randomized, controlled trial. METHODS: A multicenter, open-label efficacy and safety study of pegloticase with MTX co-treatment was conducted in patients with uncontrolled gout. Patients were administered oral MTX (15 mg/week) and folic acid (1 mg/day) 4 weeks prior to and throughout pegloticase treatment. The primary study outcome was the proportion of responders, defined as serum uric acid (sUA) < 6 mg/dL for ≥ 80% of the time during Month 6 (Weeks 20, 22, and 24). All analyses were performed on a modified intent-to-treat population, defined as patients who received ≥ 1 pegloticase infusion. RESULTS: Seventeen patients were screened and 14 patients (all men, average age 49.3 ± 8.7 years) were enrolled. On Day 1, mean sUA was 9.2 ± 2.5 mg/dL, and 12 of the 14 patients had visible tophi. At the 6-month timepoint, 11/14 (78.6%, 95% CI 49.2-95.3%) met the responder definition, with 3 patients discontinuing after meeting protocol-defined treatment discontinuation rules (preinfusion sUA values > 6 mg/dL at 2 consecutive scheduled visits). All patients tolerated MTX. No new safety concerns were identified. CONCLUSION: In this study, an increased proportion of patients maintained therapeutic response at 6 months when treated concomitantly with MTX and pegloticase as compared to the previously reported 42% using pegloticase alone. These results support the need for a randomized study of MTX or placebo with pegloticase to validate these open-label findings.

Concomitant medication use in a large, international, multicenter, placebo controlled trial of anakinra, a recombinant interleukin 1 receptor antagonist, in patients with rheumatoid arthritis.

OBJECTIVE: To examine the safety of anakinra when added to a background of standard rheumatoid arthritis (RA) medications in patients with RA with active disease. METHODS: This analysis further evaluates data from the first 6 months of a blinded, placebo controlled safety trial that had a subsequent 30 month, open label portion (not reported here). Patients with RA with a wide range of comorbid conditions, disease activity, and background medications were randomly assigned in a 4:1 allocation ratio to treatment with anakinra 100 mg or placebo administered daily by injection. Safety was assessed by comparing adverse event profiles between anakinra and placebo patients according to concomitant medications received. RESULTS: Anakinra patients (n = 1116) showed no difference in the incidence of upper respiratory infections or overall serious adverse events compared with placebo patients (n = 283). The anakinra group had more injection site reactions (72.6% vs 32.9% in placebo) and a small increase in serious infections (2.1% vs 0.4% in placebo). Anakinra's safety profile did not differ in patients receiving antihypertensive, antidiabetic, or statin drugs. CONCLUSION: This study indicates that anakinra has a good safety profile in patients typically seen in a rheumatology practice who are considered candidates for therapy with agents that are immunomodulatory and disease modifying. Except for injection site reactions and a nonstatistically although potentially clinically significant increase in serious infections in the anakinra versus the placebo groups, the addition of anakinra to a stable background regimen of RA medications introduced no other important safety risk in patients with RA.

Anakinra, a recombinant human interleukin-1 receptor antagonist (r-metHuIL-1ra), in patients with rheumatoid arthritis: A large, international, multicenter, placebo-controlled trial.

OBJECTIVE: To evaluate the safety of anakinra (a recombinant human interleukin-1 receptor antagonist) in a large population of patients with rheumatoid arthritis (RA), typical of those seen in clinical practice. METHODS: A total of 1,414 patients were randomly assigned to treatment with 100 mg of anakinra or placebo, administered daily by subcutaneous injection. Background medications included disease-modifying antirheumatic drugs, corticosteroids, and nonsteroidal antiinflammatory drugs, alone or in combination. The primary end point was safety, which was evaluated by adverse events (including infections), discontinuation from study due to adverse events, and death. RESULTS: Safety was evaluated in 1,399 patients (1,116 in the anakinra group and 283 in the placebo group; 15 patients were randomized but did not receive any study drug) during the initial 6-month, double-blind, placebo-controlled phase of this long-term safety study. Baseline demographics, disease characteristics, and concomitant medications were similar between the 2 groups. The study group included patients with numerous comorbid conditions and a wide range of RA disease activity. Serious adverse events occurred at a similar rate in the anakinra group and the placebo group (7.7% and 7.8%, respectively). Serious infectious episodes were observed more frequently in the anakinra group (2.1% versus 0.4% in the placebo group). The rate of withdrawal due to adverse events was 13.4% in the anakinra group and 9.2% in the placebo group. CONCLUSION: Results from this large, placebo-controlled safety study demonstrate that anakinra is safe and well tolerated in a diverse population of patients with RA, including those with comorbid conditions and those using multiple combinations of concomitant therapies. Although the frequency of serious infection was slightly higher in the anakinra group, no infection was attributed to opportunistic microorganisms or resulted in death.