Time-matched Baseline Research Articles

Tank cleaning temporarily increases stress and decreases affiliative behavior in zebrafish

Small, tropical fish are popular companion animals and constitute a major proportion of the vertebrates used in scientific research, but little is known about how they are affected by routine husbandry practices. Manual tank cleanings are a common and potentially stressful maintenance procedure that involves siphoning out a substantial volume of tank water, ‘vacuuming’ the substrate to remove waste, and pumping fresh water back into the tank. To examine how manual tank cleanings may affect stress and affiliative behavior in zebrafish (Danio rerio), we video recorded the behavior of zebrafish (five 110 L tanks, 10 fish/tank) at two time-points: (i) immediately after tank cleaning and (ii) approximately one hour later. For comparison, we also recorded behavior during time-matched periods the day before cleaning (baseline) and the day after cleaning (longer-term effects). All fish had been exposed to this weekly procedure for over a year prior to data collection. Results show that immediately after tank cleaning, fish spent more time lower in the water column (an indicator of negative affect in zebrafish; p < 0.02), and were less cohesive (p < 0.0001), less coordinated (p < 0.0001) and tended to be more aggressive (p < 0.08) than they were during time-matched baseline periods. An hour after tank cleaning, all behaviors returned to baseline (p’s > 0.2). On the day after cleaning, behaviors during both periods (immediately after and one-hour later) were indistinguishable from baseline (aggression: p > 0.05; all others: p’s > 0.1). These results suggest that fish, like other animals, are adversely affected by some husbandry procedures, but that the effects may be short-lived. Future research could explore ways of mitigating tank cleaning stress by, for example, giving fish more predictability and control over their exposure to the husbandry event.

In vivo cardiopulmonary impact of skeletal M3Dq DREADD expression: a pilot study

The muscarinic M3 receptor (M3R) is implicated in cardiopulmonary control and many other peripheral physiologic functions. Previous observations report mortality in mice expressing a Gq-linked designer G-protein coupled receptor (Dq) selectively in striated muscle, while M3Dq DREADD (Designer Receptor Exclusively Activated by Designer Drug), selectively expressed in skeletal muscle (SKM) impacts glucose metabolism. We investigated whether activation of SKM M3Dq impacts cardiopulmonary function. Heart rate (HR), body temperature (Tb) and locomotor activity (ACT) were measured in 4 conscious, chronically instrumented M3Dq DREADD mice and 4 wildtype controls. Circadian values of HR, BT and ACT were not different between genotypes (p > 0.05). Activation of the M3Dq DREADD by clozapine N-oxide (CNO; 0.1 mg/kg) resulted in: a significant drop in heart rate, 2 h after injection, compared with a time-matched baseline control period from the same animals (460 ± 28 vs. 532 ± 6, p < 0.05), significantly lower ACT compared to the baseline control (p < 0.05) and reduced pulmonary minute ventilation compared to pre-CNO control (p < 0.05). M3Dq DREADD activation did not cause bronchoconstriction (separate protocol), however, there was a concomitant reduction in HR, Tb and ventilation, accompanied by cardiac arrhythmias. We speculate that reductions in Tb, HR and ventilation reflect a mechanistic link between SKM Gq signaling and the metabolic responses associated with the initiation of torpor. Supported by the Canadian Institutes of Health Research (CIHR MOP-81211).

Baseline selection in concentration-QTc modeling: impact on assay sensitivity

ABSTRACT The baseline selection in concentration-QTc (C-QTc) modeling is not well studied in the literature. Time-matched baseline and pre-dose baseline have been commonly used as a covariate in C-QTc modeling for parallel and crossover study, respectively. It has been showed that the C-QTc model using time-matched baseline has a low chance of showing assay sensitivity in parallel study. To better understand the impacts of baseline section in C-QTc, we examined the original and subsampled moxifloxacin and placebo data from more than 50 of TQT studies submitted to FDA with regard to assay sensitivity. Our analyses show that baseline selection (time-matched, pre-dose, average) has an impact on prediction from C-QTc modeling and the impact depends on study design (parallel, crossover). The impact to categorical table of ΔQTc is unlikely to alter the interpretation of the outlier category (ΔQTc>60) that corresponds to the regulatory concern. The results presented here can guide C-QTc study design as well as baseline selection in C-QTc modeling.

Abstract 591: Adavosertib (AZD1775) does not prolong QT interval in patients with advanced solid tumors: A Phase I open-label study

Abstract Background: Adavosertib (AZD1775; AD), a highly selective inhibitor of WEE1 kinase, regulates S and G2/M cell-cycle checkpoints. This study (NCT03333824; Part B) assessed the effect of doses of AD on the QT interval in patients (pts) with advanced solid tumors. Methods: After a 7-14-day washout from prior short-term AD exposure, pts received AD 225 mg bid (five doses; combi therapy MTD/RP2D) on days 13 at 12-h intervals, under fasted conditions: 2 h pre-dose to 2 h post-dose. Pts underwent digital electrocardiogram (dECG) on day −1 (time-matched baseline), and dECG and pharmacokinetic (PK) sampling before AD administration and up to 12 h post-dose on days 1 and 3. Antiemetic(s) were given (1 mg granisetron ± 4 mg dexamethasone) on day −1 (baseline), and 30 min prior to AD (days 1-3). Pts had their final PK/dECG assessments on day 4, 24 h post-dose. Corrected QT interval by Fridericia (QTcF) outliers following dosing were defined as values &amp;gt;450 ms or increases from baseline &amp;gt;30 ms. Results: Of 33 enrolled pts (median age, 60.0 years, range 41-83; F:M, 18:15), 21 (64%) received AD (Part B of the study). There was no significant relationship between ΔQTcF (vs baseline) and AD concentration. The slope of the linear relationship between ΔQTcF and AD concentration was not statistically significant (P=0.27), with the 95% CI of the slope (−0.003978, 0.01351) incl 0. Model predictions of ΔQTcF at the geometric mean of AD Cmax were, on day 1 (712.8 nM) and day 3 (1462 nM), −2.4 ms (90% CI −5.9, 1.1) and −0.8 ms (90% CI −5.1, 3.6), respectively. The largest mean difference in ΔQTcF was 7.3 ms, 3 h post-dose, on day 3. On day 1, two pts had an increase in QTcF &amp;gt;30 ms, and one of these (who took mirtazapine) had increases in QTcF &amp;gt;30 ms on day 3. No QTcF &amp;gt;450 ms or increase in QTcF &amp;gt;60 ms was observed. On day 1 and day 3, there were no apparent effects of AD on mean QRS, mean PR interval or heart rate (mean change was within ± 10 bpm). Geometric mean AUC0-12 and Cmax of AD on day 1 were 4940 nM·h and 712.8 nM, respectively, vs 10810 nM·h and 1462 nM on day 3. Cmin on day 3 was 410.4 nM. Geometric least-squares mean ratios (90% CI) of AD on day 3 vs day 1 for AUC0-12 and Cmax were 231% (200, 266) and 207% (170, 251), respectively; accumulation of AD over the dosing period was ~2.3 for AUC0-12 and ~2.1 for Cmax. Median tmax of AD was 3.0 h (range 1.0-6.0) on day 1 and 2.5 h (range 1.0-3.1) on day 3. Intra-subject variability was low (5% for AUC0-12 and 9% for Cmax) on day 3. AEs were reported by 16 (76%) patients, most commonly diarrhea, nausea (each 7 [33%] pts) and vomiting (5 [24%] pts). Eleven (52%) pts had treatment-related AEs (2 [10%] pts with grade ≥3). Conclusions: No significant relationship was found between ΔQTcF and AD concentration. Modeling showed that AD does not have a clinically important effect on QT prolongation. Accumulation over the dosing period was approximately twofold, concordant with results from prior studies at this AD dose. No new safety concerns were reported. Citation Format: Mats Någård, Mei-Lin Ah-See, Karen So, James Strauss, Trisha Wise-Draper, Howard Safran, Ding Wang, Laura Nadeau, William Edenfield, Lionel D. Lewis, Dinko Rekić, Corina Dota, Lone Ottesen, Yan Li, Ganesh Mugundu. Adavosertib (AZD1775) does not prolong QT interval in patients with advanced solid tumors: A Phase I open-label study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 591.

Talazoparib has no clinically relevant effect on QTc interval in patients with advanced solid tumors.

The aims of this study were (i) to evaluate the effect of talazoparib (1 mg once daily) on cardiac repolarization in patients with advanced solid tumors by assessing corrected QT interval (QTc) and (ii) to examine the relationship between plasma talazoparib concentration and QTc. In this open-label phase 1 study, patients had continuous 12-lead ECG recordings at baseline followed by time-matched continuous ECG recordings and collection of talazoparib plasma pharmacokinetic samples predose and at 1, 2, 4, and 6 h postdose on treatment days 1 and 22 and before talazoparib administration on day 2. ECG recordings were submitted for independent central review where triplicate 10-s ECGs, extracted up to 15 min before pharmacokinetic samples, were assessed for RR, PR, QRS, and QT intervals and ECG morphology. QT interval was corrected for heart rate using Fridericia's (QTcF) and Bazett's (QTcB) formulae. Linear mixed-effects modeling was used to examine the relationship between QTc and RR interval change from baseline and plasma talazoparib concentration. Thirty-seven patients received talazoparib. Mean change in QTcF from time-matched baseline ranged from -3.5 to 6.9 ms, with the greatest change 1 h postdose on day 22. No clinically relevant changes in PR, QRS, QTcB, QTcF, or RR intervals, heart rate, or ECG morphology were observed. No concentration-dependent effect on heart rate or QTc was observed. No deaths, permanent treatment discontinuations due to adverse events were reported. Talazoparib (1 mg once daily) had no clinically relevant effects on cardiac repolarization.

C-Fos expression in the limbic thalamus following thermoregulatory and wake-sleep changes in the rat.

A cellular degeneration of two thalamic nuclei belonging to the "limbic thalamus", i.e., the anteroventral (AV) and mediodorsal (MD) nuclei, has been shown in patients suffering from Fatal Familial Insomnia (FFI), a lethal prion disease characterized by autonomic activation and severe insomnia. To better assess the physiological role of these nuclei in autonomic and sleep regulation, c-Fos expression was measured in rats during a prolonged exposure to low ambient temperature (Ta, -10°C) and in the first hours of the subsequent recovery period at normal laboratory Ta (25°C). Under this protocol, the thermoregulatory and autonomic activation led to a tonic increase in waking and to a reciprocal depression in sleep occurrence, which was more evident for REM sleep. These effects were followed by a clear REM sleep rebound and by a rebound of Delta power during non-REM sleep in the following recovery period. In the anterior thalamic nuclei, c-Fos expression was (1) larger during the activity rather than the rest period in the baseline; (2) clamped at a level in-between the normal daily variation during cold exposure; (3) not significantly affected during the recovery period in comparison to the time-matched baseline. No significant changes were observed in either the MD or the paraventricular thalamic nucleus, which is also part of the limbic thalamus. The observed changes in the activity of the anterior thalamic nuclei appear, therefore, to be more specifically related to behavioral activation than to autonomic or sleep regulation.

Abstract P3-14-07: Evaluation of the effects of talazoparib on QT interval prolongation

Abstract Background: Talazoparib (TAL), an oral poly ADP-ribose polymerase inhibitor, is under investigation in multiple oncologic clinical trials and has been submitted to the US FDA for use in patients (pts) with germline BRCA-mutated, HER2-negative advanced breast cancer. International Conference on Harmonisation guidance recommends all new drugs be evaluated for effects on cardiac repolarization in a well-controlled clinical study. For drugs for which such evaluation cannot be conducted in healthy volunteers (eg, most anticancer agents), collection of robust corrected QT (QTc) interval data from a dedicated QTc study (hybrid thorough QT/QTc study) in pts is required in the registration dossier. The effect of steady-state (ss) TAL (1 mg once daily) on cardiac repolarization in pts with advanced solid tumors was evaluated in an open-label phase 1 study (NCT03042910). Methods: Continuous 12-lead electrocardiogram (ECG) recordings were collected at baseline (Day -1); time-matched pharmacokinetic (PK) samples and continuous ECG recordings were obtained on Days 1, 2, and 22 (when TAL concentrations achieved ss). On Day -1, pts had continuous 12-lead ECG recording starting at Time 0 (Day 1 dosing time) for 6 hrs. On Days 1 and 22, ECG recording started 45 min before TAL administration and continued for 6 hrs post dose and blood samples for PK were collected before dose and at 1, 2, 4, and 6 hrs post dose. On Day 2, a 30-min ECG recording and a PK sample were obtained before dose at Time 0. Continuous ECG recordings were submitted to a central laboratory; triplicate 10-sec ECGs were extracted from a 5-min extraction window beginning 15 min before each PK collection time. ECG measurements were reported via blinded manual adjudication process and included PR interval, QT interval, RR interval, and QRS complex. The QT interval was corrected for effect of heart rate using Fridericia's correction (QTcF) and Bazett's correction (QTcB). The estimate of change from time-matched baseline and its 2-sided 90% confidence interval (CI) was calculated for each nominal time point using PROC MEANS. Additionally, a prespecified PK/pharmacodynamic (PD) model was used to describe the relationship between plasma TAL concentrations ([TAL]) and QTc. The prespecified linear mixed-effects model included [TAL], time (categorical), and treatment with random pt effects on [TAL] and the intercept. If the upper bounds (UB) of 1-sided 95% CIs of time-matched ΔQTc for all ECG time points were &amp;lt;20 msec and the UB of 1-sided 95% CIs of the predicted ΔQTc at the mean ss maximum [TAL] was &amp;lt;20 msec, the effect of TAL on QTc was not of clinical relevance. Results: 37 of 38 pts enrolled received TAL and were included in the ECG and PK/PD analyses. No pts had a postbaseline absolute maximum QTcF or QTcB ≥500 msec or ΔQTc ≥60 msec. The UB of the 1-sided 95% CI for the time-matched ΔQTcF and ΔQTcB were &amp;lt;12 msec at all nominal ECG time points. In the PK/PD analysis, the slopes (95% CI) of QTcF-[TAL] and QTcB-[TAL] relationships were -0.14 (-0.78 to 0.50) msec/ng/mL and -0.24 (-0.88 to 0.41) msec/ng/mL, respectively, indicating that TAL did not have a concentration-dependent effect on QTcF or QTcB. Conclusion: TAL does not have a clinically relevant effect on QTc. Funding: Medivation LLC, acquired by Pfizer. Citation Format: Hoffman J, Chakrabarti J, Wainberg ZA, Plotka A, Babu S, Milillo Naraine A, Kanamori D, Moroose R, Nguyen L, Wang D. Evaluation of the effects of talazoparib on QT interval prolongation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-14-07.

Rapid Dose Escalation Study of Praliciguat, a Soluble Guanylate Cyclase Stimulator, in Patients with Diabetes and Hypertension

Background: Impaired nitric oxide (NO) signaling through soluble guanylate cyclase (sGC) has been associated with microvascular complications of diabetes. Praliciguat (IW-1973), an sGC stimulator that enhances NO signaling, reduced fasting plasma glucose and proteinuria in an animal model of diabetic nephropathy. In a Phase 1 clinical study in healthy adults, doses of 15-40 mg were tolerated and lowered blood pressure (BP). Methods: This Phase 2a open-label in-clinic study assessed the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of oral praliciguat in 11 patients with type 2 diabetes mellitus (T2DM) and hypertension on stable glycemic and BP therapy. Patients received sequential 3-day dosing cycles escalating through placebo (PBO), 10, 20, 30, 40 and 50 mg praliciguat QD. Assessments included adverse events (AEs), blood chemistry, ambulatory BP and heart rate, platelet function, and reactive hyperemia index (RHI). Results: The escalating dose regimen was generally well tolerated; there were no serious or severe AEs. Escalation in 2 patients was stopped due to asymptomatic BP lowering. Overall PK showed a median Tmax of 1-3 h, low to moderate variability, and ∼2-fold accumulation supporting QD dosing. Average 12-h daytime mean arterial BP decreased by 2 to 9 mmHg relative to time-matched PBO baseline across praliciguat dose levels, while heart rate increased 4 to 7 bpm. Notable changes from PBO baseline [mean (95% CI)] at the end of treatment were seen for fasting serum glucose [-26.5 mg/dL (-43.4, -9.5], HbA1c [-0.4% (-0.8, -0.04)], cholesterol [-43 mg/dL (-67, -20)], and body weight [-3.5 kg (-4.9, -2.0)]. Praliciguat had no effect on RHI or platelet function. Conclusion: T2DM patients with hypertension on standard therapy showed improvements in hemodynamics and metabolic parameters in this small in-clinic study. These results support further evaluation of praliciguat in T2DM patients including those with complications. Disclosure J.P. Hanrahan: Employee; Self; Ironwood. J.D. Wakefield: Employee; Self; Ironwood Pharmaceuticals, Inc.. Stock/Shareholder; Self; Ironwood Pharmaceuticals, Inc.. P.J. Wilson: None. D.P. Zimmer: Employee; Self; Ironwood Pharmaceuticals, Inc.. Stock/Shareholder; Self; Ironwood Pharmaceuticals, Inc.. M. Mihova: None. J. Chickering: None. D. Ruff: None. M.L. Hall: Employee; Self; Ironwood Pharmaceuticals, Inc.. Stock/Shareholder; Self; Ironwood Pharmaceuticals, Inc. M. Currie: Employee; Self; Ironwood Pharmaceuticals, Inc. G. Milne: Employee; Self; Ironwood Pharmaceuticals, Inc.. Stock/Shareholder; Self; Ironwood Pharmaceuticals, Inc.. Employee; Spouse/Partner; Catabasis Pharmaceuticals. Stock/Shareholder; Spouse/Partner; Catabasis Pharmaceuticals. A.T. Profy: Other Relationship; Self; Ironwood Pharmaceuticals.

The composition and initial evaluation of a grimace scale in ferrets after surgical implantation of a telemetry probe.

Reliable recognition of pain is difficult in ferrets as many currently available parameters are non-specific, inconsistent and/or impractical. Grimace scales have successfully been applied to assess pain in different animal species and might also be applicable to ferrets. To compose a Ferret Grimace Scale (FGS), we studied the facial musculature of ferrets and compared lateral photographs of 19 ferret faces at six time points before and after intraperitoneal telemetry probe implantation. We identified the Action Units (AUs) orbital tightening, nose bulging, cheek bulging, ear changes and whisker retraction as potential indicators of pain in ferrets. To evaluate whether these AUs could reliably be used to identify photographs taken before and after surgery, the photographs were scored 0, 1 or 2 (not, moderately or obviously present) by 11 observers that were blinded to the treatment and timing of the photographs. All AU-scores assigned to the photographs taken five hours after surgery were significantly higher compared to their time-matched baseline scores. Further analysis using the weights that were obtained using a Linear Discriminant Analysis revealed that scoring orbital tightening alone was sufficient to make this distinction with high sensitivity, specificity and accuracy. Including weighted scores for nose bulging, cheek bulging and ear change did not change this. As these AUs had more missing values than orbital tightening, their descriptions should be re-evaluated. Including whisker retraction, which had a negative weight, resulted in lower accuracy and should therefore in its current form be left out of the FGS. Overall, the results of this study suggest that the FGS and the AU orbital tightening in particular could be useful in a multifactorial pain assessment protocol for ferrets. However, before applying the FGS in practice, it should be further validated by incorporating more time points before and after applying (different) painful stimuli, and different levels of analgesia.

Effect of alisertib, an investigational aurora a kinase inhibitor on the QTc interval in patients with advanced malignancies

SummaryAims A primary objective of this study was to investigate the effect of single and multiple doses of alisertib, an investigational Aurora A kinase inhibitor, on the QTc interval in patients with advanced malignancies. The dose regimen used was the maximum tolerated dose which was also the recommended phase 3 dose (50 mg twice daily [BID] for 7 days in 21-day cycles). Methods Patients received a single dose of alisertib (50 mg) on Day 1, and multiple doses of alisertib (50 mg BID) on Days 4 through to the morning of Day 10 of the first cycle of treatment. Triplicate ECGs were collected at intervals over 10 to 24 h via Holter recorders on Days −1 (baseline), 1 and 10. Changes from time-matched baseline values were calculated for various ECG parameters including QTc, heart rate, PR and QRS intervals. Alisertib pharmacokinetics were also assessed during the study, and an exposure-QTc analysis was conducted. Results Fifty patients were included in the QTc analysis. The upper bounds of the 95% confidence intervals for changes from time-matched baseline QTcF and QTcI values were <5 ms across all study days, time points and correction methods. Alisertib did not produce clinically relevant effects on heart rate, PR or QRS intervals. There was no evidence of a concentration-QTc effect relationship. Conclusions Alisertib does not cause QTc prolongation and can be concluded to not have any clinically relevant effects on cardiac repolarization or ECG parameters at the single agent maximum tolerated dose of 50 mg BID.

Effects of the glycine reuptake inhibitors bitopertin and RG7118 on glycine in cerebrospinal fluid: results of two proofs of mechanism studies in healthy volunteers.

Hypofunction of NMDA receptors has been implicated in neuropsychiatric disorders including schizophrenia. NMDA receptor neurotransmission can be enhanced through inhibition of glycine reuptake by the glycine transporter type 1 (GlyT1). The primary objective of these studies was to explore the relationship between plasma exposure and glycine cerebrospinal fluid (CSF) concentrations following administration of bitopertin and RG7118 in healthy volunteers. The bitopertin study comprised four dose levels (3, 10, 30 and 60mg) administered once daily for 10days. In the RG7118 study, placebo, 15 or 30mg RG7118 was administered once daily for 28days. CSF samples were taken on day -2 and day 10, and day -1 and day 26 for bitopertin and RG7118, respectively. Twenty-two and 24 subjects participated in the bitopertin and RG7118 study, respectively. In the bitopertin study, CSF glycine concentrations showed a dose-dependent increase from baseline to day 10. The geometric mean ratios (coefficient of variation) of AUC0-12 h on day 10 over baseline were 1.3 (17%), 1.3 (49%), 1.7 (18%) and 2.3 (14%) after 3, 10, 30 and 60mg, respectively. In the RG7118 study, the geometric mean ratio of glycine concentration (CV) on day 26 at 6h post-dose over time-matched baseline was approx. 1.9 (24 and 15%) for 15 and 30mg. The mechanism of action of bitopertin and RG7118, i.e. inhibition of glycine reuptake in the brain, was confirmed. The maximal increase observed in healthy volunteers was similar to the one observed in animals showing the good translatability of this biomarker.

Exploratory Biomarker Study of the Triple Reuptake Inhibitor SEP‐432 Compared to the Dual Reuptake Inhibitor Duloxetine in Healthy Normal Subjects

SEP-432 is a triple monoamine reuptake inhibitor of norepinephrine (NE), serotonin (5-HT), and dopamine (DA), based on in vitro binding studies. We sought evidence that SEP-432 engages these monoamine systems by measuring concentrations of monoamines and/or their main metabolites in cerebrospinal fluid (CSF) and plasma and comparing results to duloxetine, a dual reuptake inhibitor of NE and 5-HT. Eighteen healthy normal subjects received either SEP-432 (300 mg/day), duloxetine (60 mg/day), or placebo for 14 days in-clinic (double blind) with CSF and plasma collections at baseline (single lumbar puncture) and Day 14 (24-h CSF and plasma collection). Concentrations of monoamines and their metabolites, as well as pharmacokinetic concentrations of SEP-432 and metabolite, were quantified by liquid chromatography-tandem mass spectrometry. Compared to placebo in the Day 14 area under the curve 24-h (AUC0-24 h ) analysis, SEP-432 significantly (P < 0.05) decreased the NE metabolite dihydroxyphenylglycol (DHPG) in CSF and plasma, decreased 5-HT in plasma, and did not affect DA metabolites, while duloxetine had significant effects on DHPG and 5-HT. Time-matched baseline to Day 14 biomarker comparisons confirmed these findings. CSF monoamine biomarkers confirmed central NET activity for SEP-432 and duloxetine's dual reuptake inhibition.

CPX-351 ((Cytarabine:Daunorubicin) Liposome Injection, (Vyxeos)) Does Not Prolong Qtcf Intervals, Requires No Dose Adjustment for Impaired Renal Function and Induces High Rates of Complete Remission in Acute Myeloid Leukemia

Introduction: CPX-351 is a liposomal formulation of cytarabine and daunorubicin encapsulated at a fixed 5:1 molar ratio. It is highly effective in patients with high-risk acute myeloid leukemia (AML). This study evaluated the impact of CPX-351 (100 units/m2) on cardiac repolarization.Methods: This open-label, Phase II, pharmacokinetic (PK) and pharmacodynamic (PD) study entered AML and acute lymphocytic leukemia (ALL) patients with good risk hepatic function (Child-Pugh scores <7), and normal cardiac function (LVEF≥50%, QTcF<470 ms). Cardiac repolarization changes were assessed using conventional ECG and Holter monitor recordings. PK was assessed during the first 21 days for total cytarabine, daunorubicin, Ara-U and daunorubicinol. The relationship between CPX-351 PK, QTcF, and renal function using the equation to calculate the estimated glomerular filtration rate (eGFR) was evaluated.Results: Twenty-six patients entered the study and 21 were evaluable for QT interval change from baseline. Evidence that CPX-351 prolongs the QTcF interval was not observed. The largest absolute and mean change from time-matched baseline was 12.56 and 8.03 ms, respectively (Day 1, hour 4). Mean QTcF change on Day 5 was unchanged from baseline. QTcF intervals >480 ms were never observed and no consistent QTcF intervals >450 ms were noted. Absolute QTcF increases between 30 and 60 ms were present in 4 of 25 patients and no changes >60 ms were observed. CPX-351 plasma concentration vs. time curves for day 1 and 5 exhibited a volume of distribution approximately equal to the plasma volume with prolonged single-exponential elimination half-lives for cytarabine and daunorubicin of ≥24 hours. The PK of CPX-351 was independent of renal function. Patients with moderately impaired (eGFR=30-59 mL/min/1.73m2) renal function exhibited similar drug exposure as those with mild and normal renal function.Table 1Impact of renal function impairment on Day 5 CPX-351 PK parameters (mean, %CV):AnalyteRenal FunctionCmax (ng/mL)AUClast (ng*hr/mL)AUCinf (ng*hr/mL)T1/2 (hr)CytarabineNormal (n=3)Mean593332893146290264142.5%CV28.768.86934.1Mild (n=7)Mean580713599512360669541.0%CV31.952.452.421.8Moderate (n=3)Mean573333149303315673838.0%CV46.650.750.621.9DaunorubicinNormal (n=3)Mean2596775464687086124.9%CV23.16365.356.0Mild (n=7)Mean28686865034102142030.5%CV43.943.543.625.3Moderate (n=3)Mean2193367154281473235.4%CV50.935.933.531.2Table 2 summarizes response and transplant outcomes. One of two ALL patients achieved CR and was transplanted. Among AML patients there were 7 CR and 2 CRi of which three went on to transplant. An additional four patients became morphologically leukemia free (MLF) and were transplanted before full documentation of CR was achieved. A large majority of patients given first-line treatment with CPX-351 responded or became suitable for transplant (10/13, 77%).Table 2206 Study EfficacyDiagnosisnResponseCR/CRiTransplanted in CR/CRiInduced MLF and TransplantedNo ResponseALL-Relapsed21/01/001AML-First Line de novo85/0012AML-First Line sAML51/21/111AML-Salvage111/01/028Conclusions: Clinically relevant prolongation of QTcF is not a feature of CPX-351 treatment. CPX-351 exposure was independent of renal function, indicating no need for dose adjustment when renal function is impaired. The high rate of complete remission and referral for transplant corroborate the high level of efficacy observed in earlier studies with CPX-351. DisclosuresStuart:Sunesis: Honoraria, Other: Advisory Board, Research Funding; Astellas Pharma, Inc: Research Funding. Michaelis:Incyte: Membership on an entity's Board of Directors or advisory committees; CTI Biopharma: Membership on an entity's Board of Directors or advisory committees; Wyeth: Membership on an entity's Board of Directors or advisory committees; Pfizer: Equity Ownership. Pentikis:Celator Pharmaceuticals: Consultancy. Alvarez:Celator Pharmaceuticals, Inc.: Employment, Equity Ownership. Mayer:Celator Pharmaceuticals, Inc.: Employment, Equity Ownership. Louie:Celator Pharmaceuticals, Inc.: Employment, Equity Ownership.

Pharmacokinetics, safety, and cardiovascular tolerability of phenylephrine HCl 10, 20, and 30 mg after a single oral administration in healthy volunteers.

Background and ObjectivesPhenylephrine HCl 10 mg has been used as a nasal decongestant for over 50 years, yet only limited pharmacokinetic and metabolic data are available. The purpose of this study was to evaluate single-dose pharmacokinetics and safety of phenylephrine HCl 10, 20, and 30 mg and to assess cardiovascular tolerability compared with baseline and placebo in healthy volunteers.MethodsTwenty-eight adults were enrolled in this randomized, double-blind, placebo-controlled, single-dose, four-treatment crossover study. Subjects remained housed for 6 days to permit time-matched, serial measurements of pulse, blood pressure, and electrocardiograms (ECGs) for baseline and complete treatments on consecutive days. After fasting overnight, subjects were dosed with oral phenylephrine HCl 10, 20, or 30 mg or placebo. Pharmacokinetic blood samples were collected over 7 h, whereas pulse, blood pressure, and ECGs were measured over 12 h. Urine was collected over each 24-h period to quantify phenylephrine and metabolites.ResultsAfter oral administration, phenylephrine was rapidly absorbed with median times to maximum plasma concentrations (tmax) from 0.33 to 0.5 h. For phenylephrine HCl 10, 20, and 30 mg, the mean (standard deviation) maximum concentration (Cmax) was 1354 (954), 2959 (2122), and 4492 (1978) pg/mL, and total systemic exposure [area under the plasma concentration–time curve from time zero to infinity (AUC∞)] was 955.8 (278.5), 2346 (983.8), and 3900 (1764) pg·h/mL, respectively. Both parameters increased disproportionally with increasing dose, as β >1 in the power model. Negligible amounts of phenylephrine and phenylephrine glucuronide were excreted in urine. With increasing dose, percentages by dose of phenylephrine sulfate decreased, whereas percentages of 3-hydroxymandelic acid increased. Eight subjects reported nine mild adverse events; one (somnolence) was deemed to be treatment related. Means of time-matched differences in pulse and blood pressure from baseline showed similar fluctuations over 12 h among phenylephrine HCl doses and placebo, although small differences in systolic pressure were observed during the initial 2 h. No apparent dose-related effects were observed for Fridericia-corrected QT interval (QTcF) values, and individual changes from time-matched baseline (DQTcF).ConclusionsMaximum and total systemic exposures following singe doses of phenylephrine HCl 10, 20, and 30 mg increased disproportionally with increasing dose. Safety and cardiovascular tolerability were comparable among doses and placebo.

Effect of ceralifimod (ONO‐4641) on lymphocytes and cardiac function: Randomized, double‐blind, placebo‐controlled trial with an open‐label fingolimod arm

This randomized, double-blind, placebo-controlled, 6-arm, parallel-design study investigated cardiac and hematological pharmacodynamic effects of ceralifimod (ONO-4641), a selective sphingosine-1-phosphate (S1P) receptor modulator, over a broad dose range in direct comparison with the nonselective S1P modulator fingolimod. Healthy subjects were assigned to ceralifimod (0.01, 0.025, 0.05, or 0.10 mg), fingolimod (0.5 mg), or placebo once daily for 14 days (n = 24 per group). After 14 days of treatment, mean absolute lymphocyte count percentage change from baseline was greatest in the fingolimod (-62%) and ceralifimod 0.10 mg (-56%) groups. On treatment cessation, lymphocyte recovery was faster in the ceralifimod versus the fingolimod group. Ceralifimod showed dose- and concentration-dependent chronotropic effect. Cardiac effects in the fingolimod group were dependent on fingolimod-P concentrations. Maximum mean heart rate (HR) effect on day 1 was larger with fingolimod (placebo-adjusted change from time-matched baseline HR [ΔΔHR], -14.9 beats per minute [bpm]) versus ceralifimod (ΔΔHR, -6.2 and -12.0 bpm for the 0.05- and 0.10-mg doses, respectively). Ceralifimod's effect on the PR interval was minor. Safety biomarker results suggest that potential therapeutic doses of ceralifimod, in particular the 0.05-mg dose, might result in reduced occurrence of bradycardia, atrioventricular block absolute lymphocyte count and grade 3/4 lymphopenia compared with fingolimod 0.5 mg.

Circadian Variation and Baseline Definition in Parallel-Group Thorough QT Studies.

For thorough QT (TQT) studies employing a parallel-group design, there has been a clear regulatory preference for the use of time-matched, rather than time-averaged, baseline values to account for circadian variation when estimating the magnitude of the drug effect on the QT interval. In this paper, both historical data from parallel-group TQT studies and simulated data from assumed circadian models are utilized to comprehensively assess the performance characteristics of 3 repeated-measures analysis of covariance models. The results indicate that each analysis model performs adequately in the absence of an observed time-matched baseline imbalance between the treatment groups. However, the analysis model with time-matched baseline as a covariate performs poorly under the setting of an observed time-matched baseline imbalance between the treatment groups. The analysis model with time-averaged baseline as a covariate and the analysis model with both time-matched and time-averaged baselines as covariates provide unbiased estimates of the treatment difference and properly control the type I error rate, regardless of an observed time-matched baseline imbalance or within-patient variation in circadian parameters.

High-quality triplicate electrocardiogram monitoring in a first-in-man study: potential for early detection of drug-induced QT prolongation

QT interval prolongation is associated with an increased risk of potentially fatal ventricular tachycardias, including torsade de pointes. Regulatory guidance recommends the "thorough QT/QTc" (TQT) study as the gold standard for assessing the propensity of novel nonantiarrhythmic drugs to delay cardiac repolarization. An opportunity exists, however, to use high-quality electrocardiogram (ECG) data from first-in-man trials as an exploratory and complementary approach to gain early insight into potential risk of QT prolongation. We collected high-quality, triplicate, 12-lead ECG data during a first-in-man trial of a drug developed for the treatment of Type 2 diabetes that had shown in vitro hERG inhibition and potential to prolong QT intervals in an animal model. QTc prolongation was observed at the highest dose, leading to a maximum QTcF prolongation > 19 ms at 6 hours after the 14th daily dose. QTcF increases from time-matched baseline relative to placebo were positively correlated with peak plasma concentrations. Clinically relevant QT interval prolongations can be detected during first-in-man studies using high-quality ECG monitoring. Such data may facilitate early decision making on whether to terminate the development of a compound and invest resources in more promising molecules; and it may enable more efficient TQT study design or preclude the need for future TQT studies.

Preladenant, a selective adenosine A2A receptor antagonist, is not associated with QT/QTc prolongation

Preladenant is an orally administered adenosine2A (A2A) receptor antagonist in phase III development for Parkinson's disease treatment. This thorough QT/QTc study evaluated its potential effects on cardiac repolarization. This was a randomized, double-blind, positive- and placebo-controlled, four-period crossover study performed under steady-state exposure of clinical and supratherapeutic doses of preladenant (10 mg BID and 100 mg BID, respectively, for 5 days), moxifloxacin (400 mg on day 5), or placebo in 60 healthy adult volunteers. The potential effect on QTcF was measured by the largest upper bound of 95 % one-sided CIs for the mean changes from time-matched baseline ECG recordings compared with placebo. Plasma preladenant concentrations were also determined on day 5. The QTcF difference for moxifloxacin compared with placebo exceeded 5 ms from 1 to 12 h postdose, establishing assay sensitivity. The QTcF interval was similar between the preladenant and placebo treatment groups: the upper bound of the 95 % one-sided CI for the mean difference in QTcF between preladenant and placebo was less than 10 ms at all time points for the supratherapeutic treatment group (1.3 to 5.7 ms, mean difference: -1.3 to 2.7 ms) and the therapeutic treatment group (0.4 to 4.3 ms, mean difference: -2.1 to 1.5 ms), substantially below the threshold of regulatory concern. The supratherapeutic dose (100 mg BID) provided a Cmax margin of 6.1-fold and AUC margin of 6.9-fold, respectively, compared with 10 mg BID. At clinical and supratherapeutic doses, preladenant is not associated with QTc prolongation.

An efficient analysis of covariance model for crossover thorough QT studies with period‐specific baseline days

Baseline adjustment is an important consideration in thorough QT studies for nonantiarrhythmic drugs. For crossover studies with period-specific baseline days, we propose an analysis of covariance model with change from time-matched baseline as response, time-matched baseline for the current treatment, day-averaged baseline for the current treatment, time-matched baseline averaged across treatments, and day-averaged baseline averaged across treatments as covariates. This model adjusts for within-subject diurnal effects for each treatment and is more efficient than commonly used models for treatment comparisons. We illustrate the benefit using real clinical trial data.

Choice of Baseline in Parallel Thorough QT Studies

Although the ICH E14 Guidance [1] was adopted in 2005 there is still much debate on the appropriate baseline needed to adjust for the variable nature of the QT interval and its heart rate corrected value (QTc) in the parallel Thorough QT (TQT) study. Numerous reports have documented the influence of circadian rhythm [2], food ingestion [3], sleep [4], and autonomic tone [5] on the QT/QTc interval. In the absence of baseline measurements, these factors can make it difficult to interpret QT effects of the study drug. In this issue of Drug Safety Dr. Zhang and colleagues [6] advocate the use of a time-matched baseline in parallel TQT studies to maximize the precision and accuracy of point estimates for QTc effects. Their recommendation is based on analyses of commonly used baseline correction methods using a large data set of parallel TQT studies submitted to the FDA for statistical review by sponsors. One assumption in the choice of baseline is that it should have no influence on the magnitude of QT effects (high accuracy) and it should minimize the uncertainty of the effects (high precision). Both accuracy and precision are important for the interpretation of a TQT trial. As a result, there is much focus on the implications of using different baseline adjustments in the parallel TQT study and understanding the role each baseline definition can have in determining the outcome of the trial as either positive or negative. The distinction between a positive or negative TQT study is based on the upper bound of the 95 % one-sided confidence interval (CI) for the largest time-matched mean difference in QTc between drug and placebo (baseline adjusted). If these (double-delta) DDQTc values exclude 10 ms at all study times the result is a negative TQT study [1]. Intensive ECG monitoring is then hardly ever required in subsequent trials (phase II/III). Conversely, drugs for which an effect exceeding 10 ms cannot be excluded almost always require additional QT interval monitoring in target patients including dose-concentration effects, outlier analysis, changes in mean QTc values, analysis of QTc in subgroups of interest, and identification of individuals who develop a markedly prolonged QTc. The need for additional ECG monitoring in late phase trials can add millions to drug development and may ultimately pose financial limitations on the number of medications which can be developed [7]. The importance of correctly adjusting for baseline in the TQT study is therefore evident.