Cerebrovascular accidents in patients treated for choroidal neovascularization with ranibizumab in randomized controlled trials.

PURPOSE: To analyze cerebrovascular accidents (CVAs) pooled from large, randomized, controlled clinical trials of ranibizumab treatment for neovascular age-related macular degeneration. METHODS: Events in five trials (FOCUS, MARINA, ANCHOR, PIER, and SAILOR) were analyzed using a standard safety monitoring process. Exact methods, stratified by study, were used to test for treatment differences based on odds ratios. A stepwise logistic regression model was fit to classify subjects' risk for CVA based on medical history. Treatment differences in CVA rates at 1 year or 2 years were evaluated within risk groups using stratified exact methods. RESULTS: Pooled 2-year CVA rates were <3%; odds ratios (95% confidence intervals) for CVA risk were 1.2 (0.4-4.4) for ranibizumab 0.3-mg versus control, 2.2 (0.8-7.1) for 0.5 mg versus control, and 1.5 (0.8-3.0) for 0.5-mg versus 0.3-mg ranibizumab. No substantial increased risk of CVA for 0.5 mg versus 0.3 mg was identified in pooled analyses or any of the individual trials. In pooled analyses, the difference between 0.5-mg ranibizumab and control was larger (7.7 [1.2-177]) among high-risk CVA patients. CONCLUSION: This analysis provided some evidence, although not definitive, of a potential increased risk of CVA with ranibizumab versus control or with 0.5-mg versus 0.3-mg ranibizumab. Continued monitoring for CVA within clinical trials seems warrented.

A Phase IIIb study to evaluate the safety of ranibizumab in subjects with neovascular age-related macular degeneration.

OBJECTIVE: To evaluate the safety and efficacy of intravitreal ranibizumab in a large population of subjects with neovascular age-related macular degeneration (AMD). DESIGN: Twelve-month randomized (cohort 1) or open-label (cohort 2) multicenter clinical trial. PARTICIPANTS: A total of 4300 subjects with angiographically determined subfoveal choroidal neovascularization (CNV) secondary to AMD. METHODS: Cohort 1 subjects were randomized 1:1 to receive 0.3 mg (n = 1169) or 0.5 mg (n = 1209) intravitreal ranibizumab for 3 monthly loading doses. Dose groups were stratified by AMD treatment history (treatment-naïve vs. previously treated). Cohort 1 subjects were retreated on the basis of optical coherence tomography (OCT) or visual acuity (VA) criteria. Cohort 2 subjects (n = 1922) received an initial intravitreal dose of 0.5 mg ranibizumab and were retreated at physician discretion. Safety was evaluated at all visits. MAIN OUTCOME MEASURES: Safety outcomes included the incidence of ocular and nonocular adverse events (AEs) and serious adverse events (SAEs). Efficacy outcomes included changes in best-corrected VA over time. RESULTS: Some 81.7% of cohort 1 subjects and 49.9% of cohort 2 subjects completed the 12-month study. The average total number of ranibizumab injections was 4.9 for cohort 1 and 3.6 for cohort 2. The incidence of vascular and nonvascular deaths during the 12-month study was 0.9% and 0.7% in the cohort 1 0.3 mg group, 0.8% and 1.5% in the cohort 1 0.5 mg group, and 0.7% and 0.9% in cohort 2, respectively. The incidence of death due to unknown cause was 0.1% in both cohort 1 dose groups and cohort 2. The number of vascular deaths and deaths due to unknown cause did not differ across cohorts or dose groups. Stroke rates were 0.7%, 1.2%, and 0.6% in the 0.3 mg and 0.5 mg groups and cohort 2, respectively. At month 12, cohort 1 treatment-naïve subjects had gained an average of 0.5 (0.3 mg) and 2.3 (0.5 mg) VA letters and previously treated subjects had gained 1.7 (0.3 mg) and 2.3 (0.5 mg) VA letters. CONCLUSIONS: Intravitreal ranibizumab was safe and well tolerated in a large population of subjects with neovascular AMD. Ranibizumab had a beneficial effect on VA. Future investigations will seek to establish optimal dosing regimens for persons with neovascular AMD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Comparison of QTinno, a fully automated electrocardiographic analysis program, to semiautomated electrocardiographic analysis methods in a drug safety study in healthy subjects.

BACKGROUND: Improved automated methods for electrocardiographic (ECG) analysis are needed, particularly for drug development purposes. OBJECTIVES: This study compared a novel fully automated method for ECG analysis (QTinno; NewCardio, Santa Clara, CA) to 2 semiautomated digital methods: global measurement from the earliest QRS onset to the latest T-wave offset on representative superimposed beats (global) and tangent measurement on 3 consecutive beats in one lead (tangent). METHODS: All 3 methods were used to determine uncorrected and rate-corrected QT interval duration (QT and QTcF) and related metrics in 1422 digital 12-lead ECGs from a phase 1 drug study. Global and tangent annotations were manually adjusted by the same 3 cardiologists wherever necessary. No adjustments were made in QTinno determinations. RESULTS: QTinno returned QTcF change from time-matched baseline (DeltaQTcF) that differed minimally from both global and tangent methods (mean pairwise difference: 0.1 millisecond between QTinno and global, 1.1 milliseconds between QTinno and tangent). The average absolute QT and QTcF intervals by QTinno were approximately 5 milliseconds longer than global and 25 milliseconds longer than by tangent. QTinno had lower intrinsic variability for DeltaQTcF than either global or tangent (between-subject SD: QTinno 4.0 milliseconds, global 5.6 milliseconds, tangent 6.4 milliseconds; within-subject SD: QTinno 4.8 milliseconds, global 7.4 milliseconds, tangent 10.6 milliseconds). All methods were robust in detecting the largest placebo-adjusted mean time-matched DeltaQTcF (15-25 milliseconds) induced by study drug. CONCLUSIONS: The methods show good agreement for drug-induced QTc prolongation. Lower intrinsic variability of DeltaQTcF by QTinno could facilitate smaller sample sizes or increase study power in thorough QTc studies.

Comparing methods of measurement for detecting drug-induced changes in the QT interval: implications for thoroughly conducted ECG studies.

BACKGROUND: The aim of this study was to compare the reproducibility and sensitivity of four commonly used methods for QT interval assessment when applied to ECG data obtained after infusion of ibutilide. METHODS: Four methods were compared: (1) 12-lead simultaneous ECG (12-SIM), (2) lead II ECG (LEAD II), both measured on a digitizing board, (3) 3-LEAD ECG using a manual tangential method, and (4) a computer-based, proprietary algorithm, 12SL trade mark ECG Analysis software (AUT). QT intervals were measured in 10 healthy volunteers at multiple time points during 24 hours at baseline and after single intravenous doses of ibutilide 0.25 and 0.5 mg. Changes in QT interval from baseline were calculated and compared across ECG methods, using Bland-Altman plots. Variability was studied using a mixed linear model. RESULTS: Baseline QT values differed between methods (range 376-395 ms), mainly based on the number of leads incorporated into the measurement, with LEAD II and 3-LEAD providing the shortest intervals. The 3-LEAD generated the largest QT change from baseline, whereas LEAD II and 12-SIM generated essentially identical result within narrow limits of agreement (0.4 ms mean difference, 95% confidence interval +/- 20.5 ms). Variability with AUT (standard deviation 15.8 ms for within-subject values) was clearly larger than with 3-LEAD, LEAD II, and 12-SIM (9.6, 10.0, and 11.3 ms). CONCLUSION: This study demonstrated significant differences among four commonly used methods for QT interval measurement after pharmacological prolongation of cardiac repolarization. Observed large differences in variability of measurements will have a substantial impact on the sample size required to detect QT prolongation in the range that is currently advised in regulatory guidance.

Single oral dose safety, tolerability, and pharmacokinetics of PNU-96391 in healthy volunteers.

The safety, tolerability, and pharmacokinetics of PNU-96391, an orally active weak dopamine D2 receptor antagonist with modulatory properties of central dopaminergic function, was characterized. Fifty-three healthy normal volunteers were enrolled in this randomized, double-blinded, placebo-controlled, single-dose study. Subjects were assigned to single oral doses of placebo and 1, 3, 10, 30, 100, 150, and 200 mg PNU-96391. Safety and tolerability were assessed using telemetry, Holter monitoring, surface ECG, vital signs, safety laboratories, and adverse event reports. Pharmacokinetic parameters were determined by model-independent techniques. Adverse events were infrequent, of mild to moderate intensity, and in the dose range of 1 to 150 mg. Dose escalation was stopped at 200 mg because of severe nausea, dizziness, lightheadedness, and tachycardia. Besides the increase in heart rate, no other drug-related effects on vital signs were observed. Safety laboratory measurements were not significantly changed. Evidence of drug activity was demonstrated by a dose-dependent elevation in serum prolactin. PNU-96391 was rapidly absorbed, with maximum concentrations achieved between 0.5 and 4 hours in all subjects. The half-life of the drug was short (2 to 6 h). The main metabolite, PNU-100014, was rapidly formed, with a t(max) ranging from 1 to 6 hours. Peak levels of the metabolite are approximately half of the parent drug, and the half-life is slightly longer (4 to 10 h). Increases in dose resulted in linear increases in exposure for both PNU-96391 and PNU-100014. Hence, PNU-96391 was well tolerated at doses ranging from 1 to 150 mg.

Electrocardiographic identification of drug-induced QT prolongation: assessment by different recording and measurement methods.

BACKGROUND: Careful assessment of QT interval prolongation is required before novel drugs are approved by regulatory authorities. The choice of the most appropriate method of electrocardiogram (ECG) acquisition and QT/RR interval measurement in clinical trials requires better understanding of the differences among currently available approaches. This study compared standard and Holter-derived 12-lead ECGs for utility in detecting sotalol-induced QT/QTc and RR changes. Manual methods (digitizing pad and digital on-screen calipers) were compared for precision of QT and RR interval measurement. METHODS AND RESULTS: Sixteen hundred pairs of serial 12-lead digital ECGs were recorded simultaneously by standard resting ECG device and by continuous 12-lead digital Holter over 3 days in 39 healthy male and female volunteers. No therapy was given on the 1st day followed by 160 mg and 320 mg of sotalol on the 2nd and 3rd day, respectively. Holter-derived and standard ECGs produced nearly identical sotalol-induced QT/QTc and RR changes from baseline, as did the manual digipad and on-screen caliper measurements. The variability of on-screen QT measurement in this study was greater than that of digipad. CONCLUSIONS: Digital 12-lead Holter and standard 12-lead ECG recorders, as well as the manual digitizing pad and digital on-screen calipers, are of equal utility for the assessment of drug-induced change from baseline in QT and RR interval, although the variability of the on-screen method in this study was greater than of the digipad.

The pharmacokinetics of linezolid are not affected by concomitant intake of the antioxidant vitamins C and E.

In vitro metabolism experiments have suggested a possible role for endogenous reactive oxygen species (ROS) in the in vivo clearance of linezolid, a synthetic antibiotic of the oxazolidinone class. This observation has resulted in the hypothesis that dietary antioxidant supplements might disturb the balance of ROS in vivo and thereby lower the clearance of linezolid. The purpose of this open-label, two-group parallel design study was to investigate whether continuous intake of widely used vitamin C or vitamin E will affect the pharmacokinetics of linezolid. A total of 28 healthy volunteers (27 male and 1 female), including 22 of Chinese origin, were administered a single oral dose of 600 mg linezolid on days 1 and 8. Half of the subjects received daily oral doses of 1000 mg vitamin C on days 2 through 9, whereas the other half were administered daily oral doses of 800 IU vitamin E during the same time period. Serial blood samples for assessment of the pharmacokinetic parameters of linezolid and its two inactive metabolites were collected on days 1 and 8, whereas vitamin concentrations were measured prior to and after the vitamin intake on these days. Urine was collected on days 1 and 8 to assess the fraction of dose excreted as linezolid and its major metabolites. All linezolid samples were analyzed according to validated HPLC/MS/MS methods. Linezolid was well tolerated in both groups with no reported clinically significant adverse events. No significant changes were found between the day 1 and day 8 AUC0- infinity and Cmax values of linezolid in either the vitamin C treatment group (p = 0.55 and p = 0.64, respectively) or the vitamin E treatment group (p = 0.06 and p = 0.49, respectively). Assessment of other pharmacokinetic parameters did not imply any change across the study groups. In conclusion, linezolid pharmacokinetics are not affected by concomitant administration with vitamins C and E. Therefore, no dose adjustment is necessary in patients taking vitamin C or vitamin E. These no-effect drug interaction data are in accord with current literature indicating that antioxidant vitamins have only subtle effects on overall ROS balance in vivo.

Valdecoxib, a COX-2-specific inhibitor, does not affect cardiac repolarization.

This double-blind, four-way crossover study assessed the effect of valdecoxib on the QTc interval duration in 25 male and 9 female healthy adults. Subjects received placebo or 40 mg, 80 mg, or 120 mg valdecoxib once daily for 5 days. Serial ECGs were obtained for 24 hours before the first treatment (baseline) and on the 5th day of each treatment. The study was statistically powered to detect a difference of > or = 5.6 ms in the average daily QTc change from baseline and a > or = 7.8-ms difference in the average maximal daily change from baseline. No QTc prolongation versus placebo (Fridericia's or Bazett's correction) was observed for any valdecoxib dose. A 22% greater than proportional increase in valdecoxib AUC0-24 was observed over the 40- to 120-mg dose range, supporting the conclusiveness of the negative QTc risk assessment even at supratherapeutic doses (up to three times the maximum recommended dose of 40 mg per day) and concentrations. In conclusion, repeated administration of doses up to 120 mg valdecoxib had no effect on cardiac repolarization in healthy volunteers, suggesting that chronic administration of valdecoxib to patients would not increase the risk from cardiac arrhythmia associated with QT prolongation.

Cardiovascular effect of almotriptan in treated hypertensive patients.

OBJECTIVE: Our objective was to investigate the cardiovascular effects of almotriptan, a 5-hydroxytryptamine 1B/1D agonist, in treated patients with hypertension. METHODS: Twenty patients with hypertension controlled by medication received the following treatments in a randomized, double-blind, crossover design: one placebo tablet, one 12.5-mg almotriptan tablet, and one 25-mg almotriptan tablet. Serial blood samples for analysis of almotriptan were obtained through 24 hours after administration. Serial measurements of supine blood pressure, 12-lead electrocardiograms, and Holter electrocardiographic recordings were also obtained. Plasma almotriptan concentrations were measured with use of a liquid chromatography-tandem mass spectrometry assay. Differences between treatments in pharmacokinetic parameters were assessed with an ANOVA model appropriate for a crossover design. Blood pressure measures and QTc intervals were analyzed for treatment effects with use of a similar model. Analyses were performed on weighted mean and maximal changes from baseline for intervals from 0 to 4 and 0 to 12 hours after administration. RESULTS: Significant linear effects of dose were observed for the maximal change in diastolic blood pressure and for the maximal and mean changes in systolic blood pressure. These effects were consistent for both the 4- and 12-hour periods after dosing. Mean changes from baseline during the interval from 0 to 4 hours were 1.59 +/- 3.88, 1.85 +/- 5.94, and 4.84 +/- 5.99 mm Hg for systolic pressure and 1.38 +/- 6.95, 6.25 +/- 9.54, and 11.0 +/- 10.6 mm Hg for diastolic pressure for placebo, 12.5 mg almotriptan, and 25 mg almotriptan, respectively. No instances of hypertensive crisis were observed. No QTc interval prolongation was observed. CONCLUSIONS: Almotriptan has effects on blood pressure in subjects with controlled hypertension that are consistent with those of other members of the pharmalogic class.