Georg Golor

Management of hyperglycemia associated with pasireotide (SOM230): Healthy volunteer study

AIMS Pasireotide, a multireceptor-targeted somatostatin analogue with efficacy in Cushings disease and acromegaly, can affect glucose metabolism due to inhibition of insulin secretion and incretin hormone responses. A study was therefore conducted to evaluate different antihyperglycemic drugs in the management of pasireotide-associated hyperglycemia. METHODS This was a 1-week, Phase I, open-label study. Healthy male volunteers were randomized to pasireotide 600 μg sc bid alone or co-administered with metformin 500 mg po bid, nateglinide 60 mg po tid, vildagliptin 50mg po bid, or liraglutide 0.6 mg sc qd. An oral glucose tolerance test (OGTT) was performed on days 1 and 7 to evaluate effects on serum insulin, plasma glucose and glucagon levels. Safety/tolerability and pharmacokinetic effects were also evaluated. RESULTS Ninety healthy male volunteers were enrolled (n=18 per arm). After 7 days of treatment, plasma glucose AUC post-OGTT increased by 69% with pasireotide alone. The effect was reduced by 13%, 29%, 45% and 72% with co-administration of metformin, nateglinide, vildagliptin and liraglutide, respectively. On day 7, compared with pasireotide alone, the decrease in serum insulin was attenuated with nateglinide, metformin, liraglutide and vildagliptin co-administration (levels were 3%, 6%, 34% and 71% higher, respectively). Minimal changes in plasma glucagon were observed. Adverse events were consistent with the safety profiles of the drugs used. CONCLUSIONS Vildagliptin and liraglutide were most effective in minimizing pasireotide-associated hyperglycemia in healthy volunteers.

Safety of Hydroxocobalamin in Healthy Volunteers in a Randomized, Placebo-Controlled Study

Introduction. This randomized, double-blind, placebo-controlled, ascending-dose study was conducted in healthy volunteers to evaluate the safety of the investigational cyanide antidote hydroxocobalamin. Methods. Four ascending dosing groups received intravenous doses of 2.5, 5, 7.5 or 10 g hydroxocobalamin over 7.5 to 30 minutes at a constant infusion rate. Volunteers (n = 136) randomized 3:1 to receive hydroxocobalamin or placebo underwent a 4-day in-house observation after infusion on Day 1 and follow‐up visits on Days 8, 15, and 28. Results. The most common drug-related adverse events were asymptomatic and self-limiting chromaturia and reddening of the skin, which are attributed to the red color of hydroxocobalamin. Other adverse events included pustular/papular rash, headache, erythema at the injection site, decrease in lymphocyte percentage, nausea, pruritus, chest discomfort, and dysphagia. Hydroxocobalamin was associated with an increase in blood pressure in some volunteers. Blood pressure changes peaked toward the end of hydroxocobalamin infusion and typically returned to baseline levels by 4 hours postinfusion. Maximum mean changes from baseline in systolic blood pressure ranged from 22.6 to 27.0 mmHg across hydroxocobalamin doses compared with 0.2 to 6.7 mmHg in the corresponding placebo groups. Maximum mean change from baseline in diastolic blood pressure ranged from 14.3 to 25.4 mmHg across hydroxocobalamin doses compared with −3.0 to 3.8 mmHg in the corresponding placebo groups. Two allergic reactions that occurred within minutes after start of the 5- and 10-g hydroxocobalamin infusions were successfully managed with dexamethasone and/or dimethindene maleate. Conclusion. Timely intervention for acute cyanide poisoning could entail administration of an antidote in the prehospital setting based on a presumptive diagnosis. Results of this placebo-controlled study in healthy volunteers corroborate previous studies and French postmarketing experience in cyanide-exposed patients in suggesting that the safety profile of hydroxocobalamin is consistent with prehospital or hospital use.

Effect of the Proton Pump Inhibitor Esomeprazole on the Oral Absorption and Pharmacokinetics of Nilotinib

Nilotinib (Tasigna), a highly selective and potent BCR‐ABL tyrosine kinase inhibitor (TkI), is administered orally and has pH‐dependent aqueous solubility, with lower dissolution at higher pH. This study evaluated the effect of esomeprazole on the pharmacokinetics of nilotinib in healthy participants. Twenty‐two participants (6 women, 16 men, mean age of 44.9 ± 12.9 years) were enrolled to receive nilotinib as a single oral 400‐mg dose on days 1 and 13 and esomeprazole as 40 mg once daily on days 8 to 13. Serial blood samples were collected up to 72 hours after nilotinib dosing, and nilotinib serum concentrations were determined by a validated liquid chromatography/ tandem mass spectrometry assay. Gastric pH was also monitored in all participants. When coadministered with esomeprazole, nilotinib Cmax was decreased by 27% and AUC0‐∞ decreased by 34%. Nilotinib tmax was prolonged from 4.0 to 6.0 hours, but t1/2 was not altered. Mean gastric pH was 1.0 ± 0.5 at baseline and increased to 2.79 ± 2.50, 3.98 ± 2.27, 5.30 ± 1.70, 5.38 ± 1.26, and 5.31 ± 1.42 at predose and 1, 2, 3, and 4 hours after the fifth esomeprazole dose, respectively. These results suggested a modest reduction in the rate and extent of nilotinib absorption by esomeprazole. Nilotinib is a TKI that may be used concurrently with esomeprazole or other proton pump inhibitors.

Effects of Nilotinib on Single-Dose Warfarin Pharmacokinetics and Pharmacodynamics

AbstractBackground and Objective: Nilotinib (Tasigna®), a highly selective and potent BCR-ABL tyrosine kinase inhibitor, is approved for the treatment of chronic myeloid leukaemia in the chronic phase (CML-CP) and the accelerated phase (CML-AP) in patients resistant or intolerant to prior therapy, including imatinib. Nilotinib has shown competitive inhibition of cytochrome P450 enzyme (CYP) 2C9 in vitro, but its effect on CYP2C9 activity in humans is unknown. This study evaluated the effects of nilotinib on the pharmacokinetics and pharmacodynamics of warfarin, a sensitive CYP2C9 substrate, in healthy subjects. Methods: Twenty-four subjects (six female, 18 male, aged 21–65 years) were enrolled to receive a single oral dose of warfarin 25 mg with either a single oral dose of nilotinib 800 mg or matching placebo (all administered 30 minutes after consumption of a high-fat meal) in a crossover design. Serial blood samples were collected post-dose for determining serum concentrations of nilotinib and plasma concentrations of S- and R-warfarin. Prothrombin time (PT) and international normalized ratio (INR) values were determined as pharmacodynamic measures of warfarin activity. CYP2C9 genotyping was performed in all subjects using TaqMan® assay. Results: Sixteen subjects were identified as CYP2C9 extensive metabolizers (EMs) and eight as intermediate metabolizers (IMs). There were no CYP2C9 poor metabolizers. Pharmacokinetic parameters of S- and R-warfarin were similar between the two treatments (warfarin + nilotinib vs warfarin alone) in both the EM and the IM groups. The geometric mean ratios (90% CIs) for the maximum concentration in plasma (Cmax) and area under the concentration-time curve from time zero to infinity (AUC∞) of S-warfarin in plasma in all subjects were 0.98 (0.95, 1.02) and 1.03 (0.99, 1.07), respectively, and for R-warfarin 1.00 (0.96, 1.04) and 1.02 (0.99, 1.04), respectively. Mean ratios for the maximum observed value and AUC from time zero to the last sampling time for PT were 1.00(0.96,1.04) and 1.00(0.98,1.02), respectively, and for the maximum observed value for INR and the AUC from time zero to the last sampling time for INR were 1.00(0.97,1.03) and 1.00(0.99, 1.01), respectively. Mean ± SD serum nilotinib Cmax was 1872 ±560 ng/mL, which is comparable to steady-state Cmax in CML and gastrointestinal stromal tumour patients receiving twice-daily 400 mg doses. Adverse events observed following either treatment were generally consistent with the known safety profiles of both drugs, and no new safety issues were observed. Conclusion: The study results demonstrate that nilotinib has no effect on single-dose warfarin pharmacokinetics and pharmacodynamics. This implies that nilotinib is unlikely to inhibit CYP2C9 activity in human subjects. These findings suggest that warfarin and nilotinib may be used concurrently as needed.

Lixisenatide reduces postprandial hyperglycaemia via gastrostatic and insulinotropic effects

Lixisenatide is a once‐daily, prandial, short‐acting glucagon‐like peptide‐1 receptor agonist. Its main antidiabetic effect is to delay gastric emptying to control postprandial plasma glucose excursions. The dose–response relationship of the integrated insulinotropic and gastrostatic response to lixisenatide in healthy volunteers after a standardized liquid meal was investigated.

Safety and pharmacokinetics of olokizumab, an anti‐IL‐6 monoclonal antibody, administered to healthy male volunteers: A randomized phase I study

Interleukin‐6 (IL‐6) is implicated in the pathophysiology of several inflammatory conditions. Olokizumab, a humanized anti‐IL‐6 monoclonal antibody, selectively blocks the final assembly of the IL‐6 signaling complex. A randomized, double‐blind, placebo‐controlled, phase I dose‐escalation study assessed the safety and tolerability of escalating single doses of olokizumab administered intravenously (iv) or subcutaneously (sc) to 67 healthy male volunteers. The pharmacokinetics, pharmacodynamics and immunogenicity of olokizumab were also assessed. Olokizumab was tolerated at doses up to 3.0 mg/kg sc and 10.0 mg/kg iv; the maximum tolerated dose was not reached. No serious adverse events or withdrawals as a result of treatment‐emergent adverse events were reported. Pharmacokinetic analysis showed that both maximum serum concentration and area under the concentration–time curve increased linearly with increasing dose. Mean terminal half‐life was 31.5 days (standard deviation 12.4 days). The bioavailability of the sc doses ranged from 84.2% to 92.5%. Rapid decreases in C‐reactive protein concentrations were observed, with no dose dependency.

Effects of Yogurt and Applesauce on the Oral Bioavailability of Nilotinib in Healthy Volunteers

Nilotinib, a potent orally bioavailable BCR‐ABL tyrosine kinase inhibitor, is currently available as a hard gelatin capsule that must be swallowed whole. For patients who may have difficulty swallowing the intact capsule, an alternative mode of administration is desirable. The authors compared the bioavailability of nilotinib from the following administrations in 48 healthy subjects: (1) 400 mg nilotinib given as two 200‐mg nilotinib intact capsules; (2) contents of two 200‐mg nilotinib capsules, each capsule dispersed in 1 teaspoon of nonfat plain yogurt; and (3) contents of two 200‐mg nilotinib capsules, each capsule dispersed in 1 teaspoon of applesauce. Nilotinib absorption was modestly increased following the administration of nilotinib dispersed in yogurt. The geometric mean ratios (90% confidence intervals) for nilotinib Cmax, AUC0‐tlast, and AUC0‐inf were 1.31 (1.22‐1.41), 1.11 (1.05‐1.16), and 1.08 (1.02‐1.15), respectively. Administration of nilotinib dispersed in applesauce showed equivalent bioavailability compared with administration of nilotinib as intact capsules. The geometric mean ratios (90% confidence intervals) for nilotinib Cmax, AUC0‐tlast, and AUC0‐inf were 0.95 (0.88‐1.02), 0.99 (0.94‐1.04), and 0.97 (0.90‐1.03), respectively. Each treatment was well tolerated in the study subjects. The data support a feasible alternative method of nilotinib administration; each capsules contents may be dispersed in 1 teaspoon of applesauce and taken immediately.

The Hypoxia-inducible Factor Prolyl-Hydroxylase Inhibitor Roxadustat (FG-4592) and Warfarin in Healthy Volunteers: A Pharmacokinetic and Pharmacodynamic Drug–Drug Interaction Study

PURPOSE Roxadustat is a small-molecule hypoxia-inducible factor prolyl-hydroxylase inhibitor in late-stage clinical development for the treatment of anemia in patients with chronic kidney disease (CKD). Warfarin is an oral anticoagulant with a narrow therapeutic window that is often prescribed to treat coexisting cardiovascular diseases in patients with CKD. This clinical trial was designed to evaluate the effect of roxadustat on warfarin pharmacokinetic and pharmacodynamic parameters. METHODS This open-label, single-sequence crossover study was conducted in healthy volunteers (male or female) aged 18 to 55 years with a body mass index of 18.5 to 30.0 kg/m(2). The study consisted of 2 periods separated by a minimum washout period of 14 days. After an overnight fast, volunteers received a single oral dose of 25 mg (5 × 5 mg tablets) warfarin on Day 1 of Period 1 and Day 7 of Period 2. Volunteers received oral doses of 200 mg (2 × 100 mg tablets) roxadustat on Days 1, 3, 5, 7 (concomitant with warfarin), 9, 11, 13, and 15 of Period 2. Plasma S- and R-warfarin (unbound and total concentrations) and prothrombin time were determined at multiple time points up to 216 hours postdose. Pharmacokinetic and pharmacodynamic parameters were estimated via noncompartmental methods. Tolerability was evaluated by monitoring adverse events, laboratory assays, vital signs, and 12-lead ECGs. FINDINGS The geometric mean ratios and 90% CIs for Cmax and AUC∞ of total and unbound S- and R-warfarin (with and without roxadustat) were within the standard bioequivalence interval of 80.00% to 125.00%. Roxadustat increased the geometric mean (GM) prothrombin (PT) and international normalized ratio (INR) AUC from time zero to last measurable sample (AUCPT,last and AUCINR,last) by 24.4%. Coadministration of roxadustat and warfarin in healthy volunteers was associated with a favorable tolerability profile, with most treatment-associated adverse events mild in severity. IMPLICATIONS Based on the lack of clinically significant pharmacokinetic interactions and the limited influence on warfarin pharmacodynamic parameters, no dose adjustment of warfarin should be required when coadministered with roxadustat. ClinicalTrials.gov identifier: NCT02252731.

No QTc Prolongation with Semaglutide: A Thorough QT Study in Healthy Subjects

IntroductionSemaglutide is a glucagon-like peptide-1 (GLP-1) analog approved for the once-weekly treatment of type 2 diabetes. The objective of this 16-week, double-blind, single-center thorough QT study was to confirm that semaglutide treatment does not prolong cardiac repolarization versus placebo. Prolongation of the QT interval is a biomarker for ventricular tachyarrhythmia.MethodsIn a parallel design, 168 healthy subjects were randomized to the treatment or placebo arms, of whom 166 were treated with subcutaneous semaglutide (N = 83; escalated to a supratherapeutic dose of 1.5 mg) or placebo (N = 83). The subjects (60% males) had a mean age of 38.2 years and body mass index of 25.1 kg/m2. To assess QT assay sensitivity, subjects in the placebo group received a single 400 mg moxifloxacin dose as positive control, and placebo in a crossover fashion. The primary endpoint was the time-matched change from baseline in QT interval corrected individually for heart rate (ΔQTcI), calculated from 11 electrocardiogram recordings from 0 to 48 h after the last 1.5 mg dose. Similar assessments were made for the therapeutic 0.5 and 1.0 mg semaglutide dose levels.ResultsNo QTcI prolongation occurred with any semaglutide dose; the upper limits of two-sided 90% confidence intervals of the placebo-subtracted ΔQTcI were < 10 ms at all doses and time points. Exposure–response analysis showed no dependence of QTcI on semaglutide concentration. QT assay sensitivity was confirmed. The semaglutide safety profile was similar to that of other GLP-1 receptor agonists.ConclusionBased on investigations of QT/QTc, no concern with regard to ventricular arrhythmias was raised as semaglutide did not prolong the cardiac repolarization duration in healthy subjects.Trial RegistrationClinicalTrials.gov identifier: NCT 02064348.FundingNovo Nordisk.