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Two clinical studies were performed in healthy volunteers to investigate food and antacid effects on lesinurad, a novel selective uric acid reabsorption inhibitor approved for treatment of hyperuricemia associated with gout in combination with xanthine oxidase inhibitors. Study 1 evaluated a high-fat, high-calorie meal or high doses of antacids (3000 mg calcium carbonate or 1600 mg magnesium hydroxide/1600 mg aluminum hydroxide) on the pharmacokinetics (PK) and pharmacodynamics (PD) of 400 mg oral lesinurad. Study 2 evaluated low doses of antacids (1250 mg calcium carbonate or 800 mg magnesium hydroxide/800 mg aluminum hydroxide) on the PK and PD of 400 mg lesinurad. Food did not alter the plasma AUC of lesinurad and only reduced its Cmax by 18%. In the fasted conditions, high-dose calcium carbonate reduced the Cmax and AUC of lesinurad by 54% and 38%, respectively, whereas high-dose magnesium hydroxide/aluminum hydroxide reduced Cmax and AUC by 36% and 31%, respectively. Food enhanced the maximum serum urate (sUA)-lowering effect of lesinurad by approximately 20% despite reducing the Cmax of lesinurad. High-dose calcium carbonate decreased the urate-lowering effect approximately 20% in the first 6 hours, whereas high-dose magnesium hydroxide/aluminum hydroxide reduced the effect by 26%. Low-dose calcium carbonate or magnesium hydroxide/aluminum hydroxide in the presence of food did not significantly affect plasma lesinurad Cmax and AUC or the sUA lowering and renal handling of uric acid. In summary, study results suggest food did not meaningfully alter lesinurad PK and PD. High doses of antacids reduced lesinurad AUC up to 40% and reduced the lesinurad uric acid-lowering effect.

Lesinurad [Zurampic; 2-(5-bromo-4-(4-cyclopropylnaphthalen-1-yl)-4H-1,2,4-triazol-3-ylthio)], a selective inhibitor of uric acid reabsorption transporters approved for the treatment of gout, is a racemate of two atropisomers. The objective of this investigation was to evaluate the stereoselectivity of metabolism, the inhibitory potency on kidney uric acid reabsorption transporters (URAT1 and OAT4), and the clinical pharmacokinetics of the lesinurad atropisomers. Incubations with human liver microsomes (HLM), recombinant CYP2C9, and recombinant CYP3A4 were carried out to characterize the stereoselective formation of three metabolites: M3 (hydroxylation), M4 (a dihydrodiol metabolite), and M6 (S-dealkylation). The formation of M3 in HLM with atropisomer 1 was approximately twice as much as that with atropisomer 2, whereas formation of M4 with atropisomer 1 was 8- to 12-fold greater than that with atropisomer 2. There were no significant differences in the plasma protein binding among lesinurad and the atropisomers. Following oral administration of 400 mg lesinurad once daily for 14 days to healthy human volunteers, the systemic exposure (Cmax at steady state and area under the concentration-time curve from time zero to the time of dosing interval) of atropisomer 1 was approximately 30% lower than that of atropisomer 2, whereas renal clearance was similar. In vitro cell-based assays using HEK293 stable cells expressing URAT1 and OAT4 demonstrated that atropisomer 2 was approximately 4-fold more potent against URAT1 than atropisomer 1 and equally active against OAT4. In conclusion, lesinurad atropisomers showed stereoselectivity in clinical pharmacokinetics, metabolism, and inhibitory potency against URAT1.

Jesse Hall,1 Michael Gillen,2 Sha Liu,1 Jeffrey N Miner,1 Shakti Valdez,1 Zancong Shen,1 Caroline Lee1 1Ardea Biosciences, Inc., San Diego, CA, USA; 2AstraZeneca, Gaithersburg, MD, USA Purpose: Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for treatment of gout and asymptomatic hyperuricemia. This study evaluated verinurad pharmacokinetics, pharmacodynamics, and tolerability in healthy Japanese and non-Asian adult male subjects.Methods: This was a Phase I, randomized, single-blind, placebo-controlled study. Panels of 8 Japanese subjects were randomized to receive oral verinurad (2.5–15 mg) or placebo administered as a single dose in a fasted and fed state and as once-daily doses for 7 days in a fed state. Eight non-Asian subjects received verinurad 10 mg as a single dose (fasted and fed) and multiple doses in the fed state. Serial plasma/serum and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse events and laboratory data.Results: Of 48 randomized subjects, 46 (Japanese, 39; non-Asian, 7) completed the study. Following single or multiple doses in Japanese subjects, maximum plasma concentration (Cmax) and area under the plasma concentration–time curve (AUC) increased in a near dose-proportional manner. Time to Cmax (Tmax) was ~1.25–2.0 hours with fasting. A moderate-fat meal delayed Tmax (range 3.0–5.0 hours) and had a variable effect on AUC (0%–97% increase) and Cmax (0%–26% increase) across the dose groups. Following multiple verinurad 10 mg doses, Cmax and AUC were 38% and 23% higher, respectively, in Japanese vs non-Asian subjects, largely due to body weight differences. Mean reduction of serum urate following multiple verinurad 10 mg doses was 46% and 44% after 24 hours in Japanese and non-Asian subjects, respectively. Verinurad was well tolerated at all doses.Conclusion: Verinurad monotherapy lowered serum urate and was well tolerated in both healthy Japanese and non-Asian males, while small differences in plasma pharmacokinetics were observed. These data support further evaluation of once-daily verinurad as a treatment for gout and asymptomatic hyperuricemia. Keywords: pharmacokinetics, pharmacodynamics, selective uric acid reabsorption inhibitor, serum urate, urinary uric acid

The objective of the study was to evaluate the effect of lesinurad, a selective uric acid uptake inhibitor, alone and in combination with the xanthine oxidase inhibitor allopurinol, on serum uric acid and urinary urate excretion in patients with gout and hyperuricemia. A phase 1b, multicenter, open‐label, multiple‐dose study was carried out in patients with gout with serum uric acid ≥8 mg/dL following washout of urate‐lowering therapy. Patients were treated with allopurinol 300 mg/day alone in week 1; lesinurad 400 or 600 mg/day was added in week 2, followed by lesinurad 400 or 600 mg/day alone in week 3. Serum uric acid and urine uric acid were evaluated each week. Safety was assessed throughout the study. Lesinurad 400 or 600 mg/day added to allopurinol 300 mg/day reduced serum uric acid by 60% and 72%, respectively, versus allopurinol alone (37%) or lesinurad 400 mg/day (44%) or 600 mg/day (47%) alone. A 100% response rate of serum uric acid

Zancong Shen,1 Michael Gillen,2 Jeffrey N Miner,1 Gail Bucci,1 David M Wilson,1 Jesse W Hall1 1Ardea Biosciences, Inc., San Diego, CA, 2AstraZeneca, Gaithersburg, MD, USA Purpose: Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for the treatment of gout and asymptomatic hyperuricemia. The aim of this study was to evaluate the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in healthy adult males.Subjects and methods: This was a Phase I, randomized, double-blind, placebo-controlled, single and multiple ascending dose study. Panels of eight male subjects received a single oral dose of verinurad or placebo in either a fasted or fed state; panels of 10–12 male subjects received ascending doses of once-daily verinurad or placebo in a fasted state for 10days. Serial blood and urine samples were assayed for verinurad and uric acid. Safety was assessed by adverse event (AE) reports, laboratory tests, vital signs, and electrocardiograms (ECGs).Results: A total of 81 adult males completed the study. Following single doses of verinurad, maximum observed plasma concentration (Cmax) and area under the plasma concentration–time curve (AUC) increased in a dose-proportional manner; Cmax occurred at 0.5–0.75hours and 1.25hours in the fasted and fed states, respectively. Food decreased AUC by 23% and Cmax by 37%-53%. There was a modest accumulation of verinurad following multiple daily doses. Verinurad reduced serum urate levels by up to 62% (40mg, single dose) and 61% (10mg, multiple dose). The increase in urinary excretion of uric acid was greatest in the first 6hours after dosing and was still evident ≥24hours for verinurad doses ≥2mg. Verinurad was well tolerated at all doses. No serious AEs, severe AEs, discontinuations due to AEs, or clinically significant laboratory or ECG abnormalities were reported.Conclusion: Single and multiple doses of verinurad were well tolerated, absorption was rapid, and exposure was dose proportional. Verinurad increased urinary uric acid elimination and resulted in sustained reductions in serum urate. These data support further clinical evaluation of once-daily verinurad as a treatment for gout. Keywords: fractional excretion of uric acid, selective uric acid reabsorption inhibitor, serum urate, urinary uric acid&nbsp

Lesinurad is a selective uric acid reabsorption inhibitor approved for the treatment of hyperuricemia associated with gout in combination with xanthine oxidase inhibitors. In vitro assays indicate that lesinurad is an inducer of CYPs in the order CYP3A > CYP2C8 > CYP2C9 > CYP2C19 > CYP2B6 and an inhibitor of CYP2C8 and CYP2C9. To investigate the drug interaction potential of lesinurad, clinical drug interaction studies were conducted. Open-label studies in volunteers investigated the effects of single-/multiple-dose lesinurad on the pharmacokinetics of sildenafil and amlodipine (CYP3A4 induction), tolbutamide (CYP2C9 inhibition/induction), and repaglinide (CYP2C8 inhibition/induction). There was no apparent induction of CYP2C8 and CYP2C9 following repeated lesinurad administration, although no inhibition of CYP2C9 and modest inhibition of CYP2C8 were observed following single-dose lesinurad. Consistent with in vitro observations, lesinurad (200 mg once daily) was an inducer of CYP3A based on the effects on sildenafil exposure. Sildenafil exposure decreased by approximately 34% for Cmax and AUC when administered with multiple-dose lesinurad 200 mg and allopurinol 300 mg, relative to sildenafil alone. During lesinurad therapy, the possibility of reduced efficacy of concomitant drugs that are CYP3A substrates should be considered and their efficacy monitored because of induction of CYP3A by lesinurad.

Zancong Shen,1 Michael Gillen,2 Kathy Tieu,1 Mai Nguyen,1 Erin Harmon,1 David M Wilson,1 Bradley Kerr,1 Caroline A Lee1 1Ardea Biosciences, Inc., San Diego, CA, 2AstraZeneca LP, Gaithersburg, MD, USA Introduction: Lesinurad is a selective uric acid reabsorption inhibitor approved in the United States and Europe for treatment of gout in combination with a xanthine oxidase inhibitor. Amaximum tolerated dose study was conducted to determine the lesinurad supratherapeutic dose, followed by a thorough QTc study to characterize the effect of lesinurad on cardiac repolarization.Methods: The maximum tolerated dose study was a randomized, double-blind, placebo-controlled, single-ascending dose study that enrolled 35 healthy men and women. Lesinurad plasma exposure (maximum observed plasma concentration and area under the plasma concentration versus time curve) was determined at doses of 800mg, 1,200mg, and 1,600mg. The thorough QTc study was a double-blind, four-period, placebo-controlled crossover study with 54 healthy men and women who received single doses of lesinurad 1,600mg (supratherapeutic dose), lesinurad 400mg, moxifloxacin 400mg, and placebo in randomized sequence. Digital 12-lead electrocardiograms were recorded at eleven time points over 24hours in each treatment period. QT intervals were corrected for heart rate using an individual-specific correction factor (QTcI).Results: The upper bound of the one-sided 95% confidence interval for time-matched, placebo-subtracted, baseline-adjusted QTcI intervals (ΔΔQTcI) was 480ms or QTcI increases >30ms were observed. Moxifloxacin mean QTcI intervals were >5ms, and the lower bounds of the 90% confidence interval were >5ms at 2hours, 3hours, and 4hours, confirming assay sensitivity.Conclusion: Lesinurad, at supratherapeutic doses, does not have a significant effect on the QT interval in healthy male or female subjects. Keywords: pharmacokinetics, maximum tolerated dose study, QT interval, selective uric acid reabsorption inhibitor

Lesinurad is a selective uric acid reabsorption inhibitor approved for use in combination with xanthine oxidase inhibitors for the treatment of hyperuricemia associated with gout. In vitro, lesinurad was shown to be a weak inhibitor of cytochrome P450 (CYP)2C9 and a weak inducer of CYP3A4. Warfarin is a widely prescribed oral coumarin-based anticoagulant commonly prescribed in gout patients. In an open-label clinical study in healthy adult male subjects, the effects of multiple daily doses of 400 mg lesinurad on the pharmacokinetics and pharmacodynamics of a single dose of 25 mg warfarin (racemic mixture of R- and S- enantiomers) were evaluated. Lesinurad had no effect on the absorption or the exposure (area under the concentration-time curve [AUC] and peak concentration) of the more active S-warfarin enantiomer. A slight reduction (19%) in overall plasma exposure (AUC) was observed for the R-warfarin enantiomer. Lesinurad had no meaningful clinical impact on anticoagulation activity as measured by prothrombin time, activated partial thromboplastin time, and international normalized ratio of prothrombin time and Factor VII clotting activity. Overall, the administration of warfarin in the presence of multiple-dose lesinurad was devoid of clinically significant drug-drug interaction.

The objectives of this study were to determine the absolute bioavailability of lesinurad and to characterized its disposition in humans.The oral bioavailability assessment was performed using a clinical design of simultaneous dosing of a therapeutic oral dose of lesinurad with an intravenous infusion of [14C]lesinurad microdose. The bioavailability of lesinurad was determined to be 100%.The disposition of lesinurad in humans involves hepatic oxidation and renal elimination following administration of oral [14C]lesinurad dose.Metabolism of lesinurad occurred post-systemically with low circulating levels of metabolites 14C]lesinurad microdose. The bioavailability of lesinurad was determined to be 100%. The disposition of lesinurad in humans involves hepatic oxidation and renal elimination following administration of oral [14C]lesinurad dose. Metabolism of lesinurad occurred post-systemically with low circulating levels of metabolites

Zancong Shen, Colin Rowlings, Brad Kerr, Vijay Hingorani, Kimberly Manhard, Barry Quart, Li-Tain Yeh, Chris Storgard Ardea Biosciences, Inc. (a member of the AstraZeneca group), San Diego, CA, USA Abstract: 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. Arelative 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. Keywords: urinary excretion, urate lowering, URAT1, single and multiple doses, food effect, clearance&nbsp

Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in development for treatment of gout and asymptomatic hyperuricemia. This phase 1, single‐blind, multiple‐dose, drug‐drug interaction study evaluated the pharmacokinetics (PK), pharmacodynamics, and safety/tolerability of verinurad in combination with febuxostat in healthy male volunteers. Twenty‐three subjects were randomized and received once‐daily doses of verinurad (or placebo) or febuxostat alone (days 1‐7 and days 15‐21), or verinurad + febuxostat on days 8‐14. For combinations, subjects received verinurad 10 mg + febuxostat 40 mg or verinurad 2.5 mg + febuxostat 80 mg. Plasma/serum and urine samples were analyzed for verinurad, febuxostat, and uric acid. Safety was assessed by adverse events and laboratory tests. Febuxostat 40 mg had no effect on plasma exposure of verinurad 10 mg, whereas febuxostat 80 mg increased the maximum observed plasma concentration and the area under the plasma concentration‐time curve of verinurad 2.5 mg by 25% and 33%, respectively. Verinurad had no effect on febuxostat PK. Maximal reduction in serum urate was 76% with verinurad 10 mg + febuxostat 40 mg versus verinurad 10 mg (56%) or febuxostat 40 mg (49%) alone and was 67% with verinurad 2.5 mg + febuxostat 80 mg versus verinurad 2.5 mg (38%) or febuxostat 80 mg (57%) alone. Verinurad increased, whereas febuxostat decreased, 24‐hour fractional excretion and renal clearance of uric acid. There was no clinically significant drug‐drug interaction between verinurad and febuxostat PK. The combination resulted in greater reductions of serum urate than either drug alone and was well tolerated at the studied doses.

Verinurad (RDEA3170) is a selective uric acid reabsorption inhibitor in clinical development for treatment of hyperuricemia and gout. This phase 1b, multiple‐dose, drug‐drug interaction study evaluated the pharmacokinetics, pharmacodynamics, and tolerability of verinurad in combination with allopurinol. Adult males with gout were randomized to receive once‐daily oral doses of allopurinol 300 mg or verinurad 10 mg alone for 7 days, allopurinol 300 mg + verinurad 10 mg on days 8 to 14, and the alternative single agent on days 15 to 21. Colchicine 0.6 mg was taken prophylactically for gout flares. Plasma/serum and urine samples were assayed for verinurad, allopurinol, oxypurinol (allopurinol active metabolite), colchicine (plasma only), and uric acid. Safety was assessed by adverse events (AEs) and laboratory tests. Verinurad plasma exposure was unaffected by allopurinol. Verinurad increased the maximum observed plasma concentration (Cmax) for allopurinol by 33%; the area under the plasma concentration‐time curve (AUC) was unaffected. Oxypurinol Cmax and AUC were reduced 32% and 38%, respectively, by verinurad. Colchicine plasma exposure was unaltered by verinurad. The maximum decrease in serum urate was greater with verinurad + allopurinol (65%) than with verinurad (51%) or allopurinol (43%) alone. Compared with the baseline rate, the maximum rate of uric acid excreted in urine was +56% with verinurad, −46% with allopurinol, and unchanged with verinurad + allopurinol. No serious AEs, discontinuations due to AEs, or clinically significant laboratory abnormalities were noted. Despite decreased systemic exposure of allopurinol and oxypurinol in the presence of verinurad, the combination resulted in greater serum urate reduction compared with either drug alone and was well tolerated at the studied doses.

Verinurad (RDEA3170) is a second generation selective uric acid reabsorption inhibitor for the treatment of gout and asymptomatic hyperuricemia. Following a single oral solution of 10-mg dose of [14C]verinurad (500 μCi), verinurad was rapidly absorbed with a median time to occurrence of maximum observed concentration (Tmax) of 0.5 hours and terminal half-life of 15 hours. In plasma, verinurad constituted 21% of total radioactivity. Recovery of radioactivity in urine and feces was 97.1%. Unchanged verinurad was the predominant component in the feces (29.9%), whereas levels were low in the urine (1.2% excreted). Acylglucuronide metabolites M1 (direct glucuronidation) and M8 (glucuronidation of N-oxide) were formed rapidly after absorption of verinurad with terminal half-life values of approximately 13 and 18 hours, respectively. M1 and M8 constituted 32% and 31% of total radioactivity in plasma and were equimolar to verinurad on the basis of AUC ratios. M1 and M8 formed in the liver were biliary cleared with complete hydrolysis in the GI tract, as metabolites were not detected in the feces and/or efflux across the sinusoidal membrane; M1 and M8 accounted for 29.2% and 32.5% of the radioactive dose in urine, respectively. In vitro studies demonstrated that CYP3A4 mediated the formation of the N-oxide metabolite (M4), which was further metabolized by glucuronyl transferases (UGTs) to form M8, as M4 was absent in plasma and only trace levels were present in the urine. Several UGTs mediated the formation of M1, which could also be further metabolized by CYP2C8. Overall, the major clearance route of verinurad is metabolism via UGTs and CYP3A4 and CYP2C8.

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 121, lesinurad 400 mg/day was added on days 814 and then lesinurad was increased to 600 mg/day on days 1521. 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

Michael Gillen,1 Shakti Valdez,2 Dongmei Zhou,2 Bradley Kerr,2 Caroline A Lee,2 Zancong Shen2 1AstraZeneca LP, Gaithersburg, MD, 2Ardea Biosciences, Inc., San Diego, CA, USA Introduction: Lesinurad is a selective uric acid reabsorption inhibitor approved for the treatment of gout in combination with a xanthine oxidase inhibitor (XOI) in patients who have not achieved target serum uric acid (sUA) levels with an XOI alone. Most people with gout have chronic kidney disease. The pharmacokinetics, pharmacodynamics, and safety of lesinurad were assessed in subjects with impaired renal function. Methods: Two Phase I, multicenter, open-label, single-dose studies enrolled subjects with normal renal function (estimated creatinine clearance [eCrCl] >90mL/min; N=12) or mild (eCrCl 60–89mL/min; N=8), moderate (eCrCl 30–59mL/min; N=16), or severe (eCrCl

Background Excess body burden of uric acid promotes gout. Diminished renal clearance of uric acid causes hyperuricemia in most patients with gout, and the renal urate transporter (URAT)1 is important for regulation of serum uric acid (sUA) levels. The URAT1 inhibitors probenecid and benzbromarone are used as gout therapies; however, their use is limited by drug–drug interactions and off-target toxicity, respectively. Here, we define the mechanism of action of lesinurad (Zurampic®; RDEA594), a novel URAT1 inhibitor, recently approved in the USA and Europe for treatment of chronic gout. Methods sUA levels, fractional excretion of uric acid (FEUA), lesinurad plasma levels, and urinary excretion of lesinurad were measured in healthy volunteers treated with lesinurad. In addition, lesinurad, probenecid, and benzbromarone were compared in vitro for effects on urate transporters and the organic anion transporters (OAT)1 and OAT3, changes in mitochondrial membrane potential, and human peroxisome proliferator-activated receptor gamma (PPARγ) activity. Results After 6 hours, a single 200-mg dose of lesinurad elevated FEUA 3.6-fold (p

Background and Objectives Lesinurad is a selective uric acid reabsorption inhibitor (SURI) under investigation for the treatment of gout. This study elucidated the interaction of lesinurad with major liver and kidney transporters in vitro and evaluated the drug–drug interactions (DDIs) of lesinurad and atorvastatin, metformin, and furosemide in clinical studies. Methods Lesinurad interaction with membrane transporters was evaluated in validated transporter-expressing cell systems and analyzed by liquid scintillation counting. Healthy male subjects (ages 18–65 years; body mass index 18–32 kg/m2) received atorvastatin (40 mg; n = 28) with or without lesinurad 200 or 400 mg, or received metformin (850 mg; n = 12) or furosemide (40 mg; n = 11) with or without lesinurad 400 mg. Plasma concentrations of each concomitant drug were determined by validated liquid chromatography with tandem mass spectrometry methods. Results Lesinurad interacted in vitro with OATP1B1, OCT1, and OAT1/3 transporters. Co-administration of lesinurad 200 mg did not significantly alter plasma exposure (maximum concentration [Cmax] and area under the concentration–time curve [AUC]) of total atorvastatin (atorvastatin + hydroxyl-metabolites) or atorvastatin, while co-administration of lesinurad 400 mg increased the Cmax of total atorvastatin and atorvastatin by 17–26 %, but had no effect on AUC. Co-administration of lesinurad 400 mg had no effect on the plasma exposure of metformin. Furosemide plasma AUC was reduced by 31 % in the presence of lesinurad 400 mg, but furosemide renal clearance and diuretic activity were unchanged. Conclusions No clinically relevant DDIs were observed between lesinurad and substrates of major liver or kidney transporters.

Purpose: To assess the safety and tolerability of the small-molecule allosteric MEK inhibitor refametinib combined with sorafenib, in patients with advanced solid malignancies. Experimental Design: This phase I dose-escalation study included an expansion phase at the maximum tolerated dose (MTD). Patients received refametinib/sorafenib twice daily for 28 days, from a dose of refametinib 5 mg plus sorafenib 200 mg to a dose of refametinib 50 mg plus sorafenib 400 mg. Plasma levels of refametinib, refametinib metabolite M17, and sorafenib were measured for pharmacokinetic assessments. Tumors were biopsied at the MTD for analysis of MEK pathway mutations and ERK phosphorylation. Results: Thirty-two patients were enrolled in the dose-escalation cohort. The MTD was refametinib 50 mg twice daily plus sorafenib 400 mg twice daily. The most common treatment-related toxicities were diarrhea and fatigue. Refametinib was readily absorbed following oral administration (plasma half-life of ∼16 hours at the MTD), and pharmacokinetic parameters displayed near-dose proportionality, with less than 2-fold accumulation after multiple dosing. Another 30 patients were enrolled in the MTD cohort; 19 had hepatocellular carcinoma. The combination was associated with significantly reduced ERK phosphorylation in 5 out of 6 patients biopsied, with the greatest reductions in those with KRAS or BRAF mutations. Disease was stabilized in approximately half of patients, and 1 patient with colorectal cancer achieved a partial response at the MTD lasting approximately 1 year. Conclusions: In this phase I study, refametinib plus sorafenib was well tolerated, with good oral absorption, near-dose proportionality, and target inhibition in a range of tumor types. Clin Cancer Res; 22(10); 2368–76. ©2015 AACR.

Purpose. Oral route offers an attractive mode of drug administration, although its applications are limited by poor stability of peptides and proteins in the gastrointestinal tract. In this article, we report a novel method based on intestinal patches for oral drug delivery. This method involves the use of millimeter size mucoadhesive patches that adhere to the intestinal wall and direct solute diffusion towards the wall similar to that observed in the case of a transdermal patch. Methods. Intestinal patches were prepared by sandwiching a film of cross-linked bovine serum albumin microspheres between a film of ethyl cellulose and Carbopol/pectin. Delivery of three model drugs, sulforhodamine B, phenol red, and dextran was assessed in vitro using rat intestine. Results. In vitro tests confirmed substantial unidirectional diffusion of model drugs from the patch across the intestinal wall. The presence of ethyl cellulose layer minimized release from the edges as well as from the back side of the patch into the intestinal lumen. In vitro experiments with rat intestine showed that patches were effective in delivering model drugs across the intestine. Trans-lumenal flux of model drugs from intestinal patches was about 100-fold higher compared to that from a solution due to localization of the solute near the intestinal wall and due to minimization of drug loss into the intestinal lumen. Conclusions. Intestinal patches offer a novel approach for oral drug delivery.

Purpose: To evaluate the safety, pharmacokinetics, and pharmacodynamics of BAY 86-9766, a selective, potent, orally available, small-molecule allosteric inhibitor of mitogen-activated protein kinase 1/2 in patients with advanced solid tumors. Experimental Design: BAY 86-9766 was administered orally daily in 28-day courses, with doses escalated to establish the maximum-tolerated dose (MTD). An expanded cohort was evaluated at the MTD. Pharmacokinetic and pharmacodynamic parameters were assessed, with extracellular signal–regulated kinase (ERK) phosphorylation evaluated in paired biopsies from a subset of the expanded MTD cohort. Tumor specimens were evaluated for mutations in select genes. Results: Sixty-nine patients were enrolled, including 20 patients at the MTD. The MTD was 100 mg given once-daily or in two divided doses. BAY 86-9766 was well-tolerated. The most common treatment-related toxicities were acneiform rash and gastrointestinal toxicity. BAY 86-9766 was well-absorbed after oral administration (plasma half-life ∼12 hours), and displayed dose proportional pharmacokinetics throughout the tested dose range. Continuous daily dosing resulted in moderate accumulation at most dose levels. BAY 86-9766 suppressed ERK phosphorylation in biopsied tissue and tetradecanoylphorbol acetate–stimulated peripheral blood leukocytes. Of 53 evaluable patients, one patient with colorectal cancer achieved a partial response and 11 patients had stable disease for 4 or more courses. An ocular melanoma specimen harbored a GNAQ-activating mutation and exhibited reduced ERK phosphorylation in response to therapy. Conclusion: This phase I study showed that BAY 86-9766 was well-tolerated, with good oral absorption, dose proportional pharmacokinetics, target inhibition at the MTD, and some evidence of clinical benefit across a range of tumor types. Clin Cancer Res; 19(5); 1232–43. ©2012 AACR.

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 log 10 copies/ml (400 mg twice a day), −1.39 log 10 copies/ml (600 mg once a day [q.d.]), −1.62 log 10 copies/ml (800 mg q.d.), and −1.70 log 10 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.

For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy.

3007 Background: BAY 86-9766 is a highly selective, allosteric inhibitor of MEK1/2. A phase I dose-escalation trial was conducted to determine the maximum tolerated dose (MTD), pharmacokinetics (PK) and pharmacodynamics (PD) in patients with advanced metastatic or locally recurrent solid tumors. Methods: Sixty-nine patients received doses from 2-160 mg once daily (QD) or 50-80 mg twice daily (BID). Tumor types included 22 colorectal (CRC), 8 melanoma, 5 prostate, 5 NSCLC, 5 pancreatic, 3 adrenal, 3 cholangiocarcinoma, 2 breast and 16 other. Patients were given a single oral dose on Day 1, were off drug for 7 days, and then began a 28-day course of daily continuous dosing. If benefiting, dosing continued in 28-day courses with tumor response and PD assessed every 2 courses. Safety was assessed by adverse events (AEs), clinical laboratory tests, vital signs, ECGs, ECHO/MUGA scans and physical exams. PK was collected each course. PD assessments included circulating tumor cells, leukocyte phosphorylated ERK (...