Pharmacokinetics, pharmacodynamics, and safety of lesinurad, a selective uric acid reabsorption inhibitor, in healthy adult males.

Lesinurad is a selective uric acid reabsorption inhibitor under investigation for the treatment of gout. Single and multiple ascending dose studies were conducted to evaluate pharmacokinetics, pharmacodynamics, and safety of lesinurad in healthy males. Lesinurad was administered as an oral solution between 5 mg and 600 mg (single ascending dose; N=34) and as an oral solution or immediate-release capsules once daily (qday) between 100 mg and 400 mg for 10 days under fasted or fed condition (multiple ascending dose; N=32). Following single doses of lesinurad solution, absorption was rapid and exposure (maximum observed plasma concentration and area under the plasma concentration-time curve) increased in a dose-proportional manner. Following multiple qday doses, there was no apparent accumulation of lesinurad. Urinary excretion of unchanged lesinurad was generally between 30% and 40% of dose. Increases in urinary excretion of uric acid and reductions in serum uric acid correlated with dose. Following 400 mg qday dosing, serum uric acid reduction was 35% at 24 hours post-dose, supporting qday dosing. A relative bioavailability study in healthy males (N=8) indicated a nearly identical pharmacokinetic profile following dosing of tablets or capsules. Lesinurad was generally safe and well tolerated.

Pharmacodynamic, pharmacokinetic and tolerability evaluation of concomitant administration of lesinurad and febuxostat in gout patients with hyperuricaemia.

OBJECTIVE: The aim of this study was to evaluate the pharmacodynamics (PDs), pharmacokinetics (PKs) and safety of lesinurad (selective uric acid reabsorption inhibitor) in combination with febuxostat (xanthine oxidase inhibitor) in patients with gout. METHODS: This study was a phase IB, multicentre, open-label, multiple-dose study of gout patients with serum uric acid (sUA) >8 mg/dl following washout of urate-lowering therapy with colchicine flare prophylaxis. Febuxostat 40 or 80 mg/day was administered on days 1-21, lesinurad 400 mg/day was added on days 8-14 and then lesinurad was increased to 600 mg/day on days 15-21. sUA, urine uric acid and PK profiles were evaluated at the end of each week. Safety was assessed by adverse events, laboratory tests and physical examinations. RESULTS: Initial treatment with febuxostat 40 or 80 mg/day monotherapy resulted in 67% and 56% of subjects, respectively, achieving a sUA level <6 mg/dl. Febuxostat 40 or 80 mg/day plus lesinurad 400 or 600 mg/day resulted in 100% of subjects achieving sUA <6 mg/dl and up to 100% achieving sUA <5 mg/dl. No clinically relevant changes in the PKs of either drug were noted. The combination was well tolerated. CONCLUSION: The clinically important targets of sUA <6 mg/dl and <5 mg/dl are achievable in 100% of patients when combining lesinurad and febuxostat.

Phase 2a randomized controlled trial of short-term activity, safety, and pharmacokinetics of a novel nonnucleoside reverse transcriptase inhibitor, RDEA806, in HIV-1-positive, antiretroviral-naive subjects.

RDEA806 is a novel nonnucleoside reverse transcriptase inhibitor (NNRTI) with potent in vitro activity against wild-type and NNRTI-resistant HIV-1. A phase 2a randomized, double-blind, placebo-controlled, dose-escalating study evaluated the short-term antiviral activity, safety, and pharmacokinetics (PKs) of RDEA806 monotherapy in antiretroviral-naïve, HIV-1-infected subjects. The subjects were randomized to four cohorts comprising four dosage regimens and two formulations of RDEA806 or placebo in a 3:1 ratio within each cohort. The investigators were blinded to the results for each cohort. The subjects received RDEA806 or placebo for 7 days. The primary end point was the change in the HIV RNA load from the baseline to day 9 for each of the four RDEA806 dose regimens compared to that achieved with placebo. The RDEA806 PKs and the immune response to RDEA806 were evaluated along with the safety and tolerability of each dose. Of a total of 48 enrolled subjects, 36 subjects (9 in each cohort) were randomized to RDEA806 study drug, and 12 (3 in each cohort) took placebo. A statistically significant decrease in the viral load from the baseline to day 9 was observed for all RDEA806 treatment groups (P<0.001). On day 9, the mean changes in the HIV RNA load from that at the baseline were -1.95 log10 copies/ml (400 mg twice a day), -1.39 log10 copies/ml (600 mg once a day [q.d.]), -1.62 log10 copies/ml (800 mg q.d.), and -1.70 log1) copies/ml (1,000 mg q.d.). The pharmacokinetics were linear and dose proportional. Treatment with RDEA806 was well tolerated, and there were no discontinuations due to adverse events. In conclusion, all doses of RDEA806 were safe and well tolerated and exhibited robust antiretroviral activity in this short-term monotherapy study with antiretroviral-naïve HIV-infected subjects. RDEA806 is a potent and promising novel NNRTI.

Safety, tolerability, and tumor response of IL4-Pseudomonas exotoxin (NBI-3001) in patients with recurrent malignant glioma.

PURPOSE: This was an open-label, dose-escalation trial of intratumoral administration of IL-4 Pseudomonas exotoxin (NBI-3001) in patients with recurrent malignant glioma. PATIENTS AND METHODS: A total of 31 patients with histologically verified supratentorial grades 3 and 4 astrocytoma were studied. Of these, 25 patients were diagnosed with glioblastoma multiforme (GBM) while six were diagnosed with anaplastic astrocytoma. Patients were over 18 years of age and had Karnofsky performance scores > or = 60. Patients were assigned to one of four dose groups in a dose-escalation fashion: 6 microg/ml x 40 ml, 9 microg/ml x 40 ml, 15 microg/ml x 40 ml, or 9 microg/ml x 100 ml of NBI-3001 administered via convection-enhanced delivery intratumorally using stereotactically placed catheters. Patients were followed with serial MRI scans and clinical assessments every four weeks for the first 16 weeks and then every eight weeks until week 26. RESULTS: No drug-related systemic toxicity, as evident by lack of hematological or serum chemical changes, was apparent in any patients; treatment-related adverse effects were limited to the central nervous system. No deaths were attributable to treatment. Drug-related grade 3 or 4 toxicity was seen in 39% of patients in all dose groups and 22% of patients at the maximum tolerated dose of 6 microg/ml x 40 ml. The overall median survival was 8.2 months with a median survival of 5.8 months for the GBM patients. Six-month survival was 52% and 48%, respectively. Gadolinium-enhanced magnetic resonance imaging of the brain showed areas of decreased signal intensity within the tumor consistent with tumor necrosis following treatment in many patients. CONCLUSIONS: NBI-3001 appears to have an acceptable safety and toxicity profile when administered intratumorally in patients with recurrent malignant glioma.