Infusion-related reactions with pegloticase, a recombinant uricase for the treatment of chronic gout refractory to conventional therapy.

BACKGROUND: In clinical trials of pegloticase, a PEGylated uricase developed for treatment of gout refractory to conventional therapy, infusion-related reactions (IRs) were the second most frequent adverse event reported. OBJECTIVE: The objective of this study was to provide a detailed account of IRs with pegloticase therapy. METHODS: Data from 2 replicate, 6-month randomized trials and an open-label extension study were pooled. Infusions of pegloticase (8 mg) were administered biweekly or monthly; all patients received prophylaxis (antihistamine, acetaminophen, and corticosteroid) and were tested for urate levels prior to each infusion. An IR was defined by protocol as any otherwise unexplained adverse event or cluster of temporally related events occurring during or within 2 hours of infusion. RESULTS: Infusion-related reactions occurred in 94 (45%) of 208 patients receiving pegloticase; 10 patients reported IRs at first infusion and 84 during subsequent infusions. Chest discomfort (15%), flushing (12%), and dyspnea (11%) were the most common symptoms. Most IRs were rated mild or moderate; 7% were rated severe. All IRs resolved with slowing, interrupting, or stopping the infusion. No patient required blood pressure or ventilatory support. Infusion-related reactions were associated with loss of pegloticase urate-lowering efficacy: 91% of all IRs occurred in patients with preinfusion serum uric acid concentrations (sUA) greater than 6 mg/dL. For patients sustaining preinfusion sUA of less than 6 mg/dL, IRs occurred in fewer than 1 per 100 infusions. CONCLUSIONS: Phase 3 trial data combined with post hoc analyses demonstrated that knowledge of sUA preceding each pegloticase infusion and cessation of therapy when urate-lowering efficacy is lost provide a means to optimize the safety of pegloticase in clinical practice.

Long-term safety of pegloticase in chronic gout refractory to conventional treatment.

OBJECTIVE: To evaluate the long-term safety (up to 3 years) of treatment with pegloticase in patients with refractory chronic gout. METHODS: This open-label extension (OLE) study was conducted at 46 sites in the USA, Canada and Mexico. Patients completing either of two replicate randomised placebo-controlled 6-month trials received pegloticase 8 mg every 2 weeks (biweekly) or every 4 weeks (monthly). Safety was evaluated as the primary outcome, with special interest in gout flares and infusion-related reactions (IRs). Secondary outcomes included urate-lowering and clinical efficacy. RESULTS: Patients (n=149) received a mean±SD of 28±18 pegloticase infusions and were followed for a mean of 25±11 months. Gout flares and IRs were the most frequently reported adverse events; these were least common in patients with a sustained urate-lowering response to treatment and those receiving biweekly treatment. In 10 of the 11 patients with a serious IR, the event occurred when uric acid exceeded 6 mg/dl. Plasma and serum uric acid levels remained <6 mg/dl in most randomised controlled trial (RCT)-defined pegloticase responders throughout the OLE study and were accompanied by sustained and progressive improvements in tophus resolution and flare incidence. CONCLUSIONS: The safety profile of long-term pegloticase treatment was consistent with that observed during 6 months of RCT treatment; no new safety signals were identified. Improvements in clinical status, in the form of flare and tophus reduction initiated during RCT pegloticase treatment in patients maintaining goal range urate-lowering responses were sustained or advanced during up to 2.5 years of additional treatment.

Phase I/II study to assess the clinical pharmacology and safety of single ascending and multiple subcutaneous doses of PF-06881894 in women with non-distantly metastatic breast cancer.

PURPOSE: To evaluate the pharmacodynamics (PD), pharmacokinetics (PK), and safety of single and multiple doses of PF-06881894 (pegfilgrastim-apgf; Nyvepria™), a biosimilar to reference pegfilgrastim (Neulasta®), in women with non-distantly metastatic breast cancer. METHODS: In Phase I (Cycle 0) of this Phase I/II study, the PD response (absolute neutrophil count [ANC]; CD34 + count), PK profile, and safety of a single 3- or 6-mg subcutaneous dose of PF-06881894 were assessed in chemotherapy-naïve patients before definitive breast surgery. In Phase II (Cycles 1-4), the PD response (duration of severe neutropenia [DSN, Cycle 1], ANC [Cycles 1 and 4]) and PK profile (Cycles 1 and 4) of single and multiple 6-mg doses of PF-06881894 concomitant with chemotherapy and after definitive breast surgery were assessed. RESULTS: Twenty-five patients (mean age 59 years) were enrolled (Cycle 0, n = 12; Cycles 1-4, n = 13). In Cycle 0, PD responses and PK values were lower with 3-mg versus 6-mg PF-06881894. In Cycles 1 and 4, mean DSN was 0.667 days after single or multiple 6-mg doses of PF-06881894, respectively. In Cycle 4 versus Cycle 1, PD responses were more robust; PK values (mean area under the curve, maximum concentration) were lower; and clearance values were higher. The safety profile of PF-06881894 was similar to that for reference pegfilgrastim. CONCLUSION: PF-06881894 as a single 3- or 6-mg dose prior to definitive surgery, or multiple 6-mg/cycle doses postoperatively, with/without myelosuppressive chemotherapy, was consistent with the clinical pharmacology and safety profile of reference pegfilgrastim. TRIAL REGISTRATION: October 2017. ClinicalTrials.gov Identifier: NCT02650193. EudraCT Number: 2015-002057-35.

Effect of pegloticase on renal function in patients with chronic kidney disease: a post hoc subgroup analysis of 2 randomized, placebo-controlled, phase 3 clinical trials.

BACKGROUND: Pegloticase is approved in the US for treatment of refractory chronic gout. Since chronic kidney disease (CKD) is common in these patients, we conducted a post-hoc analysis of 2 replicate phase 3 trials and the subsequent open-label extension study to determine the effects of pegloticase on renal function in patients with CKD stages 3 and 4, as well as the effects of renal dysfunction on pegloticase efficacy and safety. FINDINGS: Patients with renal insufficiency were randomized to pegloticase 8 mg every 2 weeks (n = 42), pegloticase 8 mg every 4 weeks (n = 41), or placebo (n = 20) for 6 months as defined by the study protocols. Renal function was assessed by estimated glomerular filtration rate (eGFR). All patients completing the randomized trials could participate in an open-label extension study for a further 2.5 years. Uric acid response, the primary end point in the trials, was plasma uric acid <6.0 mg/dl for 80% of months 3 and 6.Mean eGFR in both pegloticase dosing cohorts remained constant over the randomized treatment phase and long-term open-label extension study. The number of patients achieving uric acid response was similar across CKD stages (32% stage 1, 23% stage 2, 35% stage 3, and 39% stage 4, respectively, P = 0.3). There was no difference in the pegloticase safety profile based on CKD stage. CONCLUSIONS: Pegloticase treatment does not impact eGFR in CKD patients and response to pegloticase is independent of CKD stage. TRIAL REGISTRATION: Clinical trial identifier: NCT00325195.

Tophus burden reduction with pegloticase: results from phase 3 randomized trials and open-label extension in patients with chronic gout refractory to conventional therapy.

INTRODUCTION: Two replicate randomized, placebo-controlled six-month trials (RCTs) and an open-label treatment extension (OLE) comprised the pegloticase development program in patients with gout refractory to conventional therapy. In the RCTs, approximately 40% of patients treated with the approved dose saw complete response (CR) of at least one tophus. Here we describe the temporal course of tophus resolution, total tophus burden in patients with multiple tophi, tophus size at baseline, and the relationship between tophus response and urate-lowering efficacy. METHODS: Baseline subcutaneous tophi were analyzed quantitatively using computer-assisted digital images in patients receiving pegloticase (8 mg biweekly or monthly) or placebo in the RCTs, and pegloticase in the OLE. Tophus response, a secondary endpoint in the trials, was evaluated two ways. Overall tophus CR was the proportion of patients achieving a best response of CR (without any new/enlarging tophi) and target tophus complete response (TT-CR) was the proportion of all tophi with CR. RESULTS: Among 212 patients randomized in the RCTs, 155 (73%) had ≥ 1 tophus and 547 visible tophi were recorded at baseline. Overall tophus CR was recorded in 45% of patients in the biweekly group (P = 0.002 versus placebo), 26% in the monthly group, and 8% in the placebo group after six months of RCT therapy. TT-CR rates at six months were 28%, 19%, and 2% of tophi, respectively. Patients meeting the primary endpoint of sustained urate-lowering response to therapy (responders) were more likely than nonresponders to have an overall tophus CR at six months (54% vs 20%, respectively and 8% with placebo). CONCLUSIONS: Pegloticase reduced tophus burden in patients with refractory tophaceous gout, especially those achieving sustained urate-lowering. Complete resolution of tophi occurred in some patients by 13 weeks and in others with longer-term therapy. TRIAL REGISTRATIONS: NCT00325195, NCT01356498.