Pharmacokinetic and pharmacodynamic properties of canakinumab, a human anti-interleukin-1ß monoclonal antibody.

Canakinumab is a high-affinity human monoclonal anti-interleukin-1ß (IL-1ß) antibody of the IgG1/κ isotype designed to bind and neutralize the activity of human IL-1ß, a pro-inflammatory cytokine. Canakinumab is currently being investigated on the premise that it would exert anti-inflammatory effects on a broad spectrum of diseases, driven by IL-1ß. This paper focuses on the analysis of the pharmacokinetic and pharmacodynamic data from the canakinumab clinical development programme, describing results from the recently approved indication for the treatment of cryopyrin-associated periodic syndromes (CAPS) under the trade name ILARIS®, as well as diseases such as rheumatoid arthritis, asthma and psoriasis. Canakinumab displays pharmacokinetic properties typical of an IgG1 antibody. In a CAPS patient weighing 70 kg, slow serum clearance (0.174 L/day) was observed with a low total volume of distribution at steady state (6.0 L), resulting in a long elimination half-life of 26 days. The subcutaneous absolute bioavailability was high (70%). Canakinumab displays linear pharmacokinetics, with a dose-proportional increase in exposure and no evidence of accelerated clearance or time-dependent changes in pharmacokinetics following repeated administration was observed. The pharmacokinetics of canakinumab in various diseases (e.g. CAPS, rheumatoid arthritis, psoriasis or asthma) are comparable to those in healthy individuals. No sex- or age-related pharmacokinetic differences were observed after correction for body weight. An increase in total IL-1ß was observed in both healthy subjects and all patient populations following canakinumab dosing, reflecting the ability of canakinumab to bind circulating IL-1ß. The kinetics of total IL-1ß along with the pharmacokinetics of canakinumab were characterized by a population-based pharmacokinetic-binding model, where the apparent in vivo dissociation constant, signifying binding affinity of canakinumab to circulating IL-1ß, was estimated at 1.07 ± 0.173 nmol/L in CAPS patients. During development of canakinumab a cell line change was introduced. Pharmacokinetic characterization was performed in both animals and humans to assure that this manufacturing change did not affect the pharmacokinetic/pharmacodynamic properties of canakinumab.

Canakinumab (ACZ885, a fully human IgG1 anti-IL-1ß mAb) induces sustained remission in pediatric patients with cryopyrin-associated periodic syndrome (CAPS).

INTRODUCTION: Cryopyrin-associated periodic syndrome (CAPS) represents a spectrum of three auto-inflammatory syndromes, familial cold auto-inflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease/chronic infantile neurological cutaneous and articular syndrome (NOMID/CINCA) with etiology linked to mutations in the NLRP3 gene resulting in elevated interleukin-1ß (IL-1ß) release. CAPS is a rare hereditary auto-inflammatory disease, which may start early in childhood and requires a life-long treatment. Canakinumab, a fully human anti-IL-1ß antibody, produces sustained selective inhibition of IL-1ß. This study was conducted to assess the efficacy, safety, and pharmacokinetics of canakinumab in the treatment of pediatric CAPS patients. METHODS: Seven pediatric patients (five children and two adolescents) with CAPS were enrolled in a phase II, open-label study of canakinumab in patients with CAPS. Canakinumab was administered at a dose of 2 mg/kg subcutaneously (s.c.) (for patients with body weight ≤ 40 kg) or 150 mg s.c. (for patients with body weight > 40 kg) with re-dosing upon each relapse. The primary efficacy variable was time to relapse following achievement of a complete response (defined as a global assessment of no or minimal disease activity and no or minimal rash and values for serum C-reactive protein (CRP) and/or serum amyloid A (SAA) within the normal range, < 10 mg/L). RESULTS: All patients achieved a complete response within seven days after the first dose of canakinumab and responses were reinduced on retreatment following relapse. Improvements in symptoms were evident within 24 hours after the first dose, according to physician assessments. The estimated median time to relapse was 49 days (95% CI 29 to 68) in children who received a dose of 2 mg/kg. Canakinumab was well tolerated. One serious adverse event, vertigo, was reported, but resolved during treatment. CONCLUSIONS: Canakinumab, 2 mg/kg or 150 mg s.c., induced rapid and sustained clinical and biochemical responses in pediatric patients with CAPS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT00487708.

In vivo regulation of interleukin 1beta in patients with cryopyrin-associated periodic syndromes.

The investigation of interleukin 1beta (IL-1beta) in human inflammatory diseases is hampered by the fact that it is virtually undetectable in human plasma. We demonstrate that by administering the anti-human IL-1beta antibody canakinumab (ACZ885) to humans, the resulting formation of IL-1beta-antibody complexes allowed the detection of in vivo-produced IL-1beta. A two-compartment mathematical model was generated that predicted a constitutive production rate of 6 ng/d IL-1beta in healthy subjects. In contrast, patients with cryopyrin-associated periodic syndromes (CAPS), a rare monogenetic disease driven by uncontrolled caspase-1 activity and IL-1 production, produced a mean of 31 ng/d. Treatment with canakinumab not only induced long-lasting complete clinical response but also reduced the production rate of IL-1beta to normal levels within 8 wk of treatment, suggesting that IL-1beta production in these patients was mainly IL-1beta driven. The model further indicated that IL-1beta is the only cytokine driving disease severity and duration of response to canakinumab. A correction for natural IL-1 antagonists was not required to fit the data. Together, the study allowed new insights into the production and regulation of IL-1beta in man. It also indicated that CAPS is entirely mediated by IL-1beta and that canakinumab treatment restores physiological IL-1beta production.

The PKC inhibitor AEB071 may be a therapeutic option for psoriasis.

PKC isoforms tau, alpha, and beta play fundamental roles in the activation of T cells and other immune cell functions. Here we show that the PKC inhibitor AEB071 both abolishes the production of several cytokines by activated human T cells, keratinocytes, and macrophages in vitro and inhibits an acute allergic contact dermatitis response in rats. To translate these findings into humans, single and multiple ascending oral doses of AEB071 were administered to healthy volunteers and patients with psoriasis, respectively. AEB071 was well tolerated with no clinically relevant laboratory abnormalities. Ex vivo stimulation of lymphocytes from subjects exposed to single doses of AEB071 resulted in a dose-dependent inhibition of both lymphocyte proliferation and IL2 mRNA expression. Clinical severity of psoriasis was reduced up to 69% compared with baseline after 2 weeks of treatment, as measured by the Psoriasis Area Severity Index (PASI) score. The improvement in psoriasis patients was accompanied by histological improvement of skin lesions and may be partially explained by a substantial reduction of p40+ dermal cells, which are known to mediate psoriasis. These data suggest that AEB071 could be an effective novel treatment regimen for psoriasis and other autoimmune diseases, and that AEB071 warrants long-term studies to establish safety and efficacy.

The human anti-IL-1 beta monoclonal antibody ACZ885 is effective in joint inflammation models in mice and in a proof-of-concept study in patients with rheumatoid arthritis.

INTRODUCTION: IL-1beta is a proinflammatory cytokine driving joint inflammation as well as systemic signs of inflammation, such as fever and acute phase protein production. METHODS: ACZ885, a fully human monoclonal antibody that neutralizes the bioactivity of human IL-1beta, was generated to study the potent and long-lasting neutralization of IL-1beta in mechanistic animal models as well as in a proof-of-concept study in patients with rheumatoid arthritis (RA). RESULTS: The mouse IL-1 receptor cross-reacts with human IL-1beta, and it was demonstrated that ACZ885 can completely suppress IL-1beta-mediated joint inflammation and cartilage destruction in mice. This observation prompted us to study the safety, tolerability and pharmacodynamic activity of ACZ885 in RA patients in a small proof-of-concept study--the first to be conducted in humans. Patients with active RA despite treatment with stable doses of methotrexate were enrolled in this dose escalation study. The first 32 patients were split into four cohorts of eight patients each (six were randomly assigned to active treatment and two to placebo). ACZ885 doses were 0.3, 1, 3 and 10 mg/kg, administered intravenously on days 1 and 15. To explore efficacy within 6 weeks of treatment, an additional 21 patients were randomly assigned to the 10 mg/kg cohort, resulting in a total of 20 patients dosed with 10 mg/kg and 15 patients treated with placebo. There was clinical improvement (American College of Rheumatology 20% improvement criteria) at week 6 in the 10 mg/kg treatment group; however, this did not reach statistical significance (P = 0.085). A statistically significant reduction in disease activity score was observed after 4 weeks in the 10 mg/kg group. Onset of action was rapid, because most responders exhibited improvement in their symptoms within the first 3 weeks. C-reactive protein levels decreased in patients treated with ACZ885 within 1 week. ACZ885 was well tolerated. Three patients receiving ACZ885 developed infectious episodes that required treatment. No anti-ACZ885 antibodies were detected during the study. CONCLUSION: ACZ885 administration to methotrexate-refractory patients resulted in clinical improvement in a subset of patients. Additional studies to characterize efficacy in RA and to determine the optimal dose regimen appear warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00619905.

Clinical pharmacology of lumiracoxib: a selective cyclo-oxygenase-2 inhibitor.

Lumiracoxib (Prexige) is a selective cyclo-oxygenase (COX)-2 inhibitor developed for the treatment of osteoarthritis, rheumatoid arthritis and acute pain. Lumiracoxib possesses a carboxylic acid group that makes it weakly acidic (acid dissociation constant [pKa] 4.7), distinguishing it from other selective COX-2 inhibitors. Lumiracoxib has good oral bioavailability (74%). It is rapidly absorbed, reaching maximum plasma concentrations 2 hours after dosing, and is highly plasma protein bound. Lumiracoxib has a short elimination half-life from plasma (mean 4 hours) and demonstrates dose-proportional plasma pharmacokinetics with no accumulation during multiple dosing. In patients with rheumatoid arthritis, peak lumiracoxib synovial fluid concentrations occur 3-4 hours later than in plasma and exceed plasma concentrations from 5 hours after dosing to the end of the 24-hour dosing interval. These data suggest that lumiracoxib may be associated with reduced systemic exposure, while still reaching sites where COX-2 inhibition is required for pain relief. Lumiracoxib is metabolised extensively prior to excretion, with only a small amount excreted unchanged in urine or faeces. Lumiracoxib and its metabolites are excreted via renal and faecal routes in approximately equal amounts. The major metabolic pathways identified involve oxidation of the 5-methyl group of lumiracoxib and/or hydroxylation of its dihaloaromatic ring. Major metabolites of lumiracoxib in plasma are the 5-carboxy, 4'-hydroxy and 4'-hydroxy-5-carboxy derivatives, of which only the 4'-hydroxy derivative is active and COX-2 selective. In vitro, the major oxidative pathways are catalysed primarily by cytochrome P450 (CYP) 2C9 with very minor contribution from CYP1A2 and CYP2C19. However, in patients genotyped as poor CYP2C9 metabolisers, exposure to lumiracoxib (area under the plasma concentration-time curve) is not significantly increased compared with control subjects, indicating no requirement for adjustment of lumiracoxib dose in these subjects. Lumiracoxib is selective for COX-2 compared with COX-1 in the human whole blood assay with a ratio of 515 : 1 in healthy subjects and in patients with osteoarthritis or rheumatoid arthritis. COX-2 selectivity was confirmed by a lack of inhibition of arachidonic acid and collagen-induced platelet aggregation. COX-2 selectivity of lumiracoxib is associated with a reduced incidence of gastroduodenal erosions compared with naproxen and a lack of effect on both small and large bowel permeability. Lumiracoxib does not exhibit any clinically meaningful interactions with a range of commonly used medications including aspirin (acetylsalicylic acid), fluconazole, an ethinylestradiol- and levonorgestrel-containing oral contraceptive, omeprazole, the antacid Maalox, methotrexate and warfarin (although, as in common practice, routine monitoring of coagulation is recommended when lumiracoxib is co-administered with warfarin). As such, dose adjustments are not required when co-administering these agents with lumiracoxib. In addition, moderate hepatic impairment and mild to moderate renal impairment do not appear to influence lumiracoxib exposure.

Lumiracoxib does not affect methotrexate pharmacokinetics in rheumatoid arthritis patients.

BACKGROUND: Methotrexate and nonsteroidal antiinflammatory drugs are frequently coadministered in the treatment of rheumatoid arthritis (RA). OBJECTIVE: To evaluate the effect of lumiracoxib, a novel cyclooxygenase-2 selective inhibitor, on methotrexate pharmacokinetics and short-term safety in patients with RA. METHODS: This multicenter, randomized, double-blind, placebo-controlled crossover study enrolled 18 patients (mean age 49.1 y) with stable RA. Patients were randomized to receive methotrexate 7.5-15 mg orally once weekly plus either lumiracoxib 400 mg/day or placebo for 7 days. Patients then received the other treatment combination for an additional 7 days. Serial blood and urine were collected for 24 hours after the methotrexate dose on day 1 (methotrexate alone) and days 8 and 15 (combination treatment). RESULTS: Plasma methotrexate pharmacokinetics (AUC(0-t), maximum concentration [C(max)], time to C(max)) and methotrexate protein binding were similar for methotrexate alone (108.0 ng.h/mL, 26.7 ng/mL, 1.5 h, and 57.1%, respectively), methotrexate/lumiracoxib (110.2 ng.h/mL, 27.5 ng/mL, 1.0 h, and 53.7%, respectively), and methotrexate/placebo (101.8 ng.h/mL, 22.6 ng/mL, 1.0 h, and 57.0%, respectively). Similarly, no clinically significant difference was found in the urinary excretion of methotrexate. Mean exposure to the 7-OH metabolite was lower when methotrexate was given with lumiracoxib compared with placebo, shown by a reduction in AUC and C(max), although similar amounts of the metabolite were recovered in urine following both lumiracoxib and placebo. Coadministration of methotrexate and lumiracoxib was well tolerated. CONCLUSIONS: Lumiracoxib had no significant effect on the pharmacokinetics, protein binding, or urinary excretion of coadministered methotrexate in patients with RA.

Pharmacokinetics of lumiracoxib in plasma and synovial fluid.

BACKGROUND: Lumiracoxib is a new cyclo-oxygenase-2 (COX-2) selective inhibitor in development for the treatment of rheumatoid arthritis, osteoarthritis and acute pain. OBJECTIVE: To investigate the pharmacokinetics of lumiracoxib in plasma and knee joint synovial fluid from patients with rheumatoid arthritis. DESIGN: Open-label multiple-dose study evaluating the steady-state pharmacokinetics of lumiracoxib in plasma and synovial fluid after 7 days of treatment with lumiracoxib 400 mg once daily. PATIENT POPULATION: Males and females aged 18-75 years with rheumatoid arthritis, having moderate to significant synovial fluid effusion of the knee. OUTCOME MEASURES: Following a 7-day washout period for previous nonsteroidal anti-inflammatory drugs, 22 patients (17 female, 5 male) received lumiracoxib 400 mg once daily for seven consecutive days. On day 7, following an overnight fast, a final dose of lumiracoxib was administered and serial blood and synovial fluid samples were collected for up to 28 hours. Lumiracoxib and its metabolites (4'-hydroxy-lumiracoxib and 5-carboxy-4'-hydroxy-lumiracoxib) were measured by validated high performance liquid chromatography-mass spectrometry methods. The steady-state pharmacokinetics of lumiracoxib were evaluated in plasma and synovial fluid by both a population pharmacokinetic model and noncompartmental analysis. RESULTS: Lumiracoxib was rapidly absorbed (peak plasma concentration at 2 hours) and the terminal elimination half-life in plasma was short (6 hours). Lumiracoxib concentrations were initially higher in plasma than in synovial fluid; however, from 5 hours after administration until the end of the 28-hour assessment period, concentrations of lumiracoxib were higher in synovial fluid than in plasma. Peak drug concentration in synovial fluid occurred 3-4 hours later than the peak plasma concentration. The mean steady-state trough concentration of lumiracoxib in synovial fluid (454 microg/L) was approximately three times higher than the mean value in plasma (155 microg/L), and the area under the concentration-time curve from 12 to 24 hours after administration was 2.6-fold higher for synovial fluid than for plasma. Median lumiracoxib protein binding was similar in plasma and synovial fluid (range 97.9-98.3%). Concentrations of 4'-hydroxy-lumiracoxib, the active COX-2 selective metabolite, remained low in comparison with parent drug in both plasma and synovial fluid. The concentration of lumiracoxib in synovial fluid at 24 hours after administration would be expected to result in substantial inhibition of prostaglandin E(2) formation. CONCLUSION: The kinetics of distribution of lumiracoxib in synovial fluid are likely to extend the therapeutic action of the drug beyond that expected from plasma pharmacokinetics. These data support the use of lumiracoxib in a once-daily regimen for the treatment of rheumatoid arthritis.

Concomitant administration of lumiracoxib and a triphasic oral contraceptive does not affect contraceptive activity or pharmacokinetic profile.

This study evaluated the effect of lumiracoxib on the pharmacokinetics and pharmacodynamics of ethinyl estradiol (EE) and levonorgestrel (LN) in Triphasil-28 (a triphasic oral contraceptive). Females stabilized on Triphasil-28 continued on Triphasil-28 alone for another month (Treatment Period 1), then also received lumiracoxib (400 mg daily) or placebo for 28 days each (Periods 2 and 3) in a double-blind crossover design. Plasma pharmacokinetic profiles were assessed on Day 21 of Periods 2 and 3. Progesterone and plasma sex hormone binding globulin (SHBG) concentrations were measured before and 2 hours after Triphasil-28 administration on Day 21 of all three treatment periods. Lumiracoxib had no significant effect on EE or LN pharmacokinetics or on progesterone or SHBG concentrations, indicating that anovulation and Triphasil-28 effectiveness was maintained. Adverse events were similar for lumiracoxib and placebo. Therefore, no clinically important consequences are anticipated if lumiracoxib is coadministered with oral contraceptives containing EE or LN.

Lack of effect of omeprazole or of an aluminium hydroxide/magnesium hydroxide antacid on the pharmacokinetics of lumiracoxib.

OBJECTIVE: To evaluate the effects of multiple doses of omeprazole and of a single dose of an aluminium hydroxide/magnesium hydroxide (Al/Mg) antacid on the single-dose plasma pharmacokinetics of lumiracoxib. STUDY DESIGN: Open-label, randomised, three-period, crossover study. POPULATION STUDIED: Healthy subjects aged 18-65 years. METHODS: Fourteen subjects who met eligibility criteria were each administered three treatments in random order: (A) lumiracoxib 400 mg as a single oral dose; (B) oral omeprazole 20 mg once daily for 4 consecutive days, then lumiracoxib 400 mg as a single oral dose just prior to oral omeprazole 20 mg on day 5; and (C) lumiracoxib 400 mg as a single oral dose immediately prior to a 20 mL dose of Al/Mg antacid (magnesium hydroxide 800 mg and aluminium hydroxide 900 mg). The interval between each lumiracoxib dose was 7 days. Analysis of variance was performed to determine whether lumiracoxib alone differed from lumiracoxib plus omeprazole or from lumiracoxib plus Al/Mg antacid for overall exposure (area under the concentration-time curve from zero to infinity [AUC( infinity )]) and peak concentration (C(max)), with treatment sequence, subject, period and treatment as factors. Ratios of geometric means between lumiracoxib plus omeprazole and lumiracoxib plus Al/Mg antacid to lumiracoxib alone (reference) were calculated for AUC( infinity ) and C(max). If the mean ratios, with 90% CIs, fell within the interval 0.80-1.25, the treatments were considered equivalent. RESULTS: Arithmetic mean plasma lumiracoxib concentration-time profiles were similar for all treatments, with a rapid rise in concentration after administration, reaching C(max) values (mean +/- SD) of 9.24 +/- 1.96, 8.81 +/- 2.30, and 10.43 +/- 3.24 mg/L within 2-3 hours for treatments A, B and C, respectively. AUC( infinity ) was similar for the three treatments (36.75 +/- 7.73, 34.88 +/- 8.40 and 35.50 +/- 5.72 mg. h/L). All ratios of geometric means with 90% CIs fell within the interval used for establishing bioequivalence, except for the C(max) comparison between lumiracoxib plus Al/Mg antacid and lumiracoxib alone, which was 1.11 (0.95, 1.31). CONCLUSIONS: Coadministration of lumiracoxib with omeprazole or with an Al/Mg antacid had no clinically significant effect on lumiracoxib single-dose plasma pharmacokinetics. Lumiracoxib can, therefore, be administered concurrently with either of these agents without need for lumiracoxib dosage alteration.

Pharmacokinetics and metabolism of lumiracoxib in healthy male subjects.

Lumiracoxib (Prexige; 2-[(2-fluoro-6-chlorophenyl)amino]-5-methyl-benzeneacetic acid) is a novel, chemically distinct cyclooxygenase-2 selective inhibitor, which has been developed for the treatment of osteoarthritis, rheumatoid arthritis, and acute pain. The absorption, metabolism, disposition, and mass balance of [14C]lumiracoxib were investigated in four healthy male subjects after a single 400-mg oral dose. Serial blood and complete urine and feces were collected for 168 h postdose. Lumiracoxib was rapidly absorbed, achieving mean plasma concentrations >1 microg/ml within 1 h of dosing. Unchanged drug in plasma accounted for 81 to 91% of radioactivity up to 2.5 h postdose, suggesting a modest first-pass effect; unchanged drug was the major circulating component in plasma, accounting for approximately 43% of the AUC(0 to 24 h). The terminal half-life of lumiracoxib in plasma was 6.5 h. Major plasma metabolites were the 5-carboxy, 4'-hydroxy, and 4'-hydroxy-5-carboxy derivatives. Excretion involved both renal (54.1%) and fecal (42.7%) routes, and dose recovery was almost complete (96.8%). Lumiracoxib was extensively metabolized before excretion, with little unchanged drug in urine (3.3% of dose) or feces (2.0% of dose). The major metabolic pathways of lumiracoxib were oxidation of the 5-methyl group and hydroxylation of the dihaloaromatic ring. Glucuronic acid conjugates of lumiracoxib metabolites (and to a minor extent lumiracoxib itself) were identified, although there was no evidence of cysteine, mercapturic acid, or glutathione conjugates. In summary, orally administered lumiracoxib is rapidly absorbed and undergoes extensive metabolism before excretion via urine and feces, with no evidence of formation of potentially reactive metabolites.

Assessment of lumiracoxib bioavailability from targeted sites in the human intestine using remotely activated capsules and gamma scintigraphy.

PURPOSE: To determine the bioavailability and pharmacokinetic profile of lumiracoxib from different sites in the gastrointestinal tract. METHODS: Subjects (11 healthy adult males) were randomized to receive a 100 mg lumiracoxib dose, via a site-specific radiolabeled delivery capsule, to the stomach (internal reference), proximal small bowel, distal small bowel, or ascending colon. Gamma scintigraphy was used for real-time visualization of capsule location, and a radiofrequency signal was used to activate capsules at target site. RESULTS: Ten subjects completed the study. The mean capsule activation times for the stomach, proximal small bowel, distal small bowel, and ascending colon were 0.22, 1.52, 3.43, and 11.46 h post dose, respectively. Lumiracoxib was well absorbed from the proximal and distal small bowel, with AUC(0-infinity) ratios 104% (86, 127)% and 110% (89, 136)%, respectively. The highest Cmax (2413 ng/ml) and AUC(0-infinity) for lumiracoxib were in the distal small bowel (6842 ng x h/ml). Effective absorption was observed from the ascending colon, with an AUC(0-infinity) ratio of 85% (69, 104)% vs. the reference. CONCLUSIONS: Lumiracoxib is rapidly and efficiently absorbed throughout the gastrointestinal tract.

Pharmacology and gastrointestinal safety of lumiracoxib, a novel cyclooxygenase-2 selective inhibitor: An integrated study.

BACKGROUND AND AIMS: Lumiracoxib is a structurally novel, acidic selective inhibitor of cyclooxygenase (COX)-2. We coordinated existing methodologies in a single study to evaluate potency, selectivity, and effect on the human gastrointestinal tract. METHODS: Twenty four healthy subjects (aged 18-45 years, 12 female) received high dose lumiracoxib (800 mg every day), standard dose naproxen (500 mg twice a day), or placebo for 8 days in a double-blind randomized crossover study. At the start and end of each dosing period, COX-2 selectivity was assessed by ex vivo serum thromboxane B(2) (COX-1) and lipopolysaccharide stimulated prostaglandin (PG) E(2) (COX-2), mucosal injury by endoscopy, and small and large bowel permeability by 0- to 5-hour and 5- to 24-hour (51)Cr-EDTA absorption. Plasma lumiracoxib was measured 2 hours after dosing on day 8 and vortex-stimulated ex vivo gastric mucosal PGE(2) synthesis at the end of each treatment period by enzyme immunoassay. RESULTS: Lumiracoxib was well absorbed and demonstrated similar potency to naproxen as a COX-2 inhibitor (77% and 66% inhibition, respectively, vs. placebo), but it differed in being more selective (24% and 97% inhibition of thromboxane B(2) vs. placebo). Gastric PGE(2) was reduced by 69% by naproxen (P < 0.001 vs. placebo) and 29% by lumiracoxib (P < 0.01 vs. placebo and naproxen). No subjects developed gastroduodenal erosions on lumiracoxib (vs. 75% on naproxen and 12.5% on placebo). (51)Cr-EDTA absorption increased significantly with naproxen but not lumiracoxib. CONCLUSIONS: Lumiracoxib is a potent selective inhibitor of COX-2 that causes little or no endoscopically detected stomach or duodenal injury or changes in bowel permeability.

Lumiracoxib: pharmacokinetic and pharmacodynamic profile when coadministered with fluconazole in healthy subjects.

This two-way crossover study evaluated the effect of fluconazole on the pharmacokinetics and selective COX-2 inhibition of lumiracoxib. Thirteen healthy subjects were randomized to fluconazole (day 1: 400 mg; days 2-4: 200 mg) or no drug. On day 4, all subjects received a single dose of lumiracoxib (400 mg). Lumiracoxib pharmacokinetics were assessed during the following 48 hours. Thromboxane B(2) (TxB(2)) inhibition was measured prior to lumiracoxib dosing and 2 hours afterwards. Fluconazole caused a small (18%) but not clinically relevant increase in lumiracoxib mean AUC(0- infinity ) but had no effect on lumiracoxib mean C(max). The geometric mean ratio (lumiracoxib plus fluconazole/lumiracoxib alone) for AUC(0- infinity ) was 1.19 (90% confidence interval [CI] = 1.12, 1.27) and for C(max) was 1.11 (90% CI = 0.98, 1.27). The decrease in TxB(2) from predose was not significantly different for lumiracoxib (11.8%) or lumiracoxib plus fluconazole (7.1%); no correlation between lumiracoxib concentration and TxB(2) decrease was seen. As fluconazole is a strong inhibitor of cytochrome P450 (CYP) 2C9, other CYP2C9 inhibitors are unlikely to affect lumiracoxib pharmacokinetics with clinical relevance, making dosage adjustment unnecessary.

Influence of delayed initiation of cyclosporine on everolimus pharmacokinetics in de novo renal transplant patients.

We quantified the influence of delayed initiation of cyclosporine on everolimus pharmacokinetics in order to provide dosing guidance for kidney transplant patients. In a randomized multicenter study, 56 de novo kidney transplant patients received everolimus, basiliximab, corticosteroids and either immediate (n = 40) or delayed (n = 16) initiation of cyclosporine based on renal function. Everolimus and cyclosporine predose blood levels (Cmin) were obtained over the first 3 months post-transplant. Everolimus Cmin averaged 9-11 ng/mL in the immediate cyclosporine group over the first 3 months. In the delayed cyclosporine group, average everolimus Cmins were significantly lower by 2.9-fold in the absence vs. presence of cyclosporine: 2.9 +/- 2.8 vs. 8.3 +/- 3.7 ng/mL (p < 0.001). Likewise, the within-patient ratio of everolimus Cmins in the presence/absence of cyclosporine averaged 2.9 (range, 0.7-5.6). Both everolimus and cyclosporine blood concentrations need to be monitored in kidney transplant patients with delayed graft function during the period when cyclosporine is withheld and shortly after its initiation. Dosing of everolimus needs to be adjusted to take into account an average threefold increase in everolimus exposure when cyclosporine is added to the regimen.

Everolimus in de novo cardiac transplantation: pharmacokinetics, therapeutic range, and influence on cyclosporine exposure.

We evaluated exposure, safety, and efficacy data from an international Phase 3 trial of everolimus in de novo heart transplantation to characterize the longitudinal pharmacokinetics of everolimus and cyclosporine and to identify a therapeutic concentration range for everolimus. We randomized 634 patients to receive either 0.75 mg everolimus twice daily, 1.5 mg everolimus twice daily, or azathioprine in addition to corticosteroids and cyclosporine. At 8 visits during the first 6 months after transplantation, we obtained 2,328 everolimus trough levels (Cmin) and 129 area-under-the-curve (AUC) profiles over the dosing interval in patients treated with everolimus; we collected 3,258 cyclosporine trough concentrations and 174 profiles in all 3 treatment arms. We used median-effect analysis to characterize exposure-response associations between everolimus average Cmin vs freedom from biopsy-confirmed acute rejection; maximum cholesterol, low density lipoprotein, triglyceride, and creatinine levels; and minimum leukocyte and platelet counts. Everolimus Cmins averaged 5.2 +/- 3.8 ng/ml and 9.4 +/- 6.3 ng/ml at the lower and upper dose levels. A 17% underproportionality was noted in Cmins; however, peak exposure and AUC were consistent with dose proportionality. Everolimus exposure was stable during the 6-month period. Interindividual variability was 37% for AUC and 40% for Cmin. The latter parameter was not influenced to a clinically relevant extent by sex, age, or weight. The Cmin was well correlated with AUC (r2 = 0.81). Everolimus Cmin was significantly related to freedom from rejection (p = 0.02) with 3 ng/ml being an informative lower threshold for efficacy. Thrombocytopenia, defined as <75 x 10(9)/liter, was related significantly to Cmin (p = 0.03); however, the incidence in this study was too low to establish an upper end for the therapeutic range. Lower doses of cyclosporine (by 15% to 19%) were used in patients treated with everolimus to achieve cyclosporine Cmins and AUCs similar to those in patients treated with azathioprine. Everolimus exposure was dose proportional and stable during the first 6 months after transplantation. Interindividual pharmacokinetic variability was high but not influenced by common demographic covariates. We observed a significantly increased risk of acute rejection at everolimus trough levels <3 ng/ml, which constitutes the lower therapeutic concentration limit when everolimus is used with conventionally dosed cyclosporine. Everolimus-related adverse events were manageable up to the highest troughs (22 ng/ml) observed in this population. We could not derive a precise upper therapeutic concentration limit from these data.

Pharmacokinetics of an everolimus-cyclosporine immunosuppressive regimen over the first 6 months after kidney transplantation.

The pharmacokinetics of everolimus were characterized over the first 6 months post transplant in 731 patients receiving either 0.75 or 1.5 mg bid everolimus in addition to cyclosporine and corticosteroids. Pharmacokinetic data consisted of 4014 everolimus trough concentrations (Cmin) obtained in all patients and 659 area under the concentration-time curve (AUC) -profiles obtained at months 2, 3, and 6 in a subset of 261 patients. Cmins averaged 4.3 +/- 2.4 and 7.2 +/- 4.2 ng/mL at 0.75 and 1.5 mg bid, indicating a 20% under-proportionality at the upper dose level. Cmins were 19-34% lower in the first month compared with months 2 through 6-values. AUC was dose-proportional and stable over time, averaging 77 +/- 32 and 136 +/- 57 ng.h.mL-1 at the two dose levels. Within- and between-patient variability in AUC were 27% and 31%, respectively. There was no influence of sex, age (16-66 years), or weight (42-132 kg) on AUC. Everolimus exposure was significantly lower by an average 20% in blacks. Everolimus exposure was relatively stable over the first 6 months post transplant, with no major departure from dose-proportionality over the therapeutic dose range. Weight-adjusted dosing (mg/kg) does not appear warranted. Black patients may have lower bioavailability and/or higher clearance of everolimus compared with white patients.

Clinical development of an everolimus pediatric formulation: relative bioavailability, food effect, and steady-state pharmacokinetics.

The immunosuppressant everolimus used in organ transplantation is formulated as a conventional tablet for adults and a dispersible tablet that can be administered in water for pediatric use. As part of the pediatric clinical development program, the relative bioavailability and food effect for the dispersible tablet were evaluated in healthy adult subjects as a prelude to characterizing the steady-state pharmacokinetics in pediatric kidney allograft recipients. In a randomized, open-label, three-way crossover study, 24 healthy adults received single 1.5-mg oral doses of everolimus as (1) six 0.25-mg dispersible tablets in water, (2) two 0.75-mg conventional tablets, and (3) six 0.25-mg dispersible tablets in water after a high-fat breakfast. Cmax and AUC were evaluated by standard bioequivalence testing to determine relative bioavailability and to quantify the effect of food. In a multicenter open-label efficacy/safety trial, pediatric renal allograft recipients received 0.8 mg/m2 (maximum 1.5 mg) bid everolimus as dispersible tablets in water. Serial trough concentrations over the first week and a steady-state pharmacokinetic profile on day 7 posttransplant were collected in 19 patients ranging from ages 2 to 16 years old. The bioavailability of everolimus from the dispersible tablet was 10% lower relative to the conventional tablet, with a ratio (90% confidence interval) of 0.90 (0.76-1.07). After a high-fat meal, tmax was delayed by a median 2.5 hours, and Cmax was reduced by 50%. Overall absorption, however, was not affected by food inasmuch as the fed/fasting AUC ratio was 0.99 (0.83-1.17). In pediatric patients, steady state was reached between days 3 and 5. The corresponding steady-state parameters were as follows: Cmin, 4.4 +/- 1.7 ng/ml; Cmax, 13.6 +/- 4.2 ng/ml; and AUC, 87 +/- 27 ng.h/ml. Steady-state concentration-time profiles in pediatric transplant patients receiving the dispersible tablet were comparable to those of adult patients receiving the conventional tablet when both were dosed to yield similar trough concentrations. If a pediatric patient is converted from the everolimus dispersible tablet to the conventional tablet, this should be based on a 1:1 milligram switch with subsequent therapeutic drug monitoring to further individualize the dose as needed. The dispersible tablet formulation should be taken consistently either with or without food to minimize fluctuations in exposure over time.

Effect of rifampin on apparent clearance of everolimus.

OBJECTIVE: To assess the influence of the CYP3A4 enzyme inducer rifampin on the pharmacokinetics of the immunosuppressant everolimus to provide guidance for their coadministration. METHODS: In this open-label, single-sequence, crossover study, 12 healthy subjects received a single oral 4-mg dose of everolimus alone and again after an 8-day pretreatment with rifampin 600 mg/d. Urinary excretion of 6beta-hydroxycortisol was measured at various time points during rifampin treatment as a marker of CYP3A4 induction. RESULTS: Urine excretion of 6beta-hydroxycortisol was significantly elevated during treatment with rifampin compared with prestudy, indicating enzyme induction. When everolimus was coadministered during rifampin treatment, the apparent clearance of everolimus was significantly increased, on average by 172%. This was manifested as a decrease in maximum concentration in all subjects, on average by 58% (range 14-73%). The AUC remained unaffected in 1 subject (although 6beta-hydroxycortisol indicated enzyme induction) and decreased in the other 11 subjects. The average decrease in AUC in the full study population was 63% (range 0-82%). Everolimus half-life was reduced significantly, from an average of 32 hours to 24 hours. CONCLUSIONS: In everolimus-treated patients for whom rifampin is indicated, alternative agents with less enzyme induction potential than rifampin could be considered. Alternatively, the dose of everolimus could be individually titrated based on everolimus therapeutic drug monitoring during rifampin therapy.

Exposure-response relationships for everolimus in de novo kidney transplantation: defining a therapeutic range.

BACKGROUND: Exposure, safety, and efficacy data from the two everolimus randomized, double-blind phase 3 trials were evaluated to identify a therapeutic concentration range applicable in de novo kidney transplantation. METHODS: A total of 695 evaluable everolimus-treated patients received either 0.75 or 1.5 mg bid in addition to corticosteroids and cyclosporine (troughs 150-400 ng/ml in month 1 and 100-300 ng/ml thereafter). A total of 3355 everolimus trough levels (Cmin) were obtained in weeks 1 and 2 and months 1, 2, 3, and 6 after transplantation. Each patient's average Cmin was calculated and the values were divided into quintiles: 1.0-3.4, 3.5-4.5, 4.6-5.7, 5.8-7.7, 7.8-15.0 ng/ml (139 patients per quintile). Efficacy was freedom from biopsy-confirmed acute rejection. Safety measures were maximum total cholesterol and triglyceride levels and minimum leukocyte and platelet counts. A sigmoid exposure-response model was used to test the significance of these Cmin-efficacy and Cmin-safety relationships. RESULTS: Freedom from acute rejection was significantly related to Cmin with an incidence of 68% at 1.0-3.4 ng/ml, 81-86% at 3.5-7.7 ng/ml, and 91% at 7.8-15.0 ng/ml (P=0.03). The incidence of hypercholesterolemia, defined as >6.5 mmol/liter, ranged from 76 to 87% over the exposure range without a significant relation to Cmin (P=0.37). The incidence of hypertriglyceridemia, defined as >2.9 mmol/liter, rose from 59 to 77% across the exposure groups (P=0.02). Leukocytopenia, defined as <4x10(9)/liter, occurred in 11-19% of patients across the exposure quintiles showing no relationship to Cmin (P=0.76). The incidence of thrombocytopenia, defined as <100x10(9)/liter, occurred in