Objective: Current extended-release (ER) formulations of psychostimulants used for treatment of attention-deficit/hyperactivity disorder (ADHD) provide an extended duration of ADHD symptom control; however, the onset of efficacy can be protracted and variable, leaving the early morning untreated. The primary objective was to characterize the single-dose pharmacokinetics and tolerability of HLD200, an evening-dosed, delayed-release (DR) and ER formulation of methylphenidate (MPH), in healthy adults and in adolescents and children with ADHD.Methods: The pharmacokinetics and tolerability of a single, oral evening dose of HLD200 (54 mg) were evaluated in two single-center open-label studies: the first in healthy adults (n = 12) and the second in adolescents (n = 18) and children (n = 11) with ADHD. Primary pharmacokinetic endpoints were the rate and extent of MPH absorption (Cmax and area under the curve [AUC]) and time to peak concentration (Tmax). These parameters were calculated using noncompartmental analysis.Results: HLD200 produced a pharmacokinetic profile characterized by an 8- to 10-hour delay in MPH release, followed by a period of extended controlled release, resulting in an ascending absorption profile that coincided with the early morning and afternoon. Mean values (coefficient of variation [CV]%) of weight-adjusted pharmacokinetic parameters were similar in adults and in adolescents and children with ADHD: Cmax ([ng/mL]/[mg/kg]) was 9.1 (35.2), 8.8 (34.5), and 7.4 (30.1); AUC0–t ([ng · h/mL]/[mg/kg]) was 126.5 (35.5), 129.4 (34.8), and 129.7 (27.3); and Tmax (hours) was 15.6 (11.1), 17.1 (14.5), and 17.7 (14.1), respectively. Intersubject variability in the mean time to achieve ascending plasma MPH concentrations of 2, 3, 4, and 5 ng/mL was low (CV: 7.8%–17.7%).Conclusions: Evening-dosed HLD200 produces the intended DR and ER pharmacokinetic profile that provides a consistent predictable delay in initial MPH release until the early morning, followed by extended release across the day. The body weight-adjusted pharmacokinetics of HLD200 were similar between adults and adolescents and children with ADHD.

The objective of the present work was to use modeling and simulation to inform trial design of a proof-of-concept study for agents used in the treatment of hyperhidrosis. Data were available from 36 subjects who received the vehicle, 2% or 4% topical glycopyrrolate wipes daily for 4 weeks, with response (hyperhidrosis disease severity scale [HDSS] and sweat production [SP]) measured weekly. The HDSS and SP time courses were best described using a longitudinal model with maximum response achieved by 1 week. Glycopyrrolate 4% had a higher HDSS responder rate than 2% (50% vs 33%) and placebo (0%) at week 1. Mean change from baseline (mg/5 min [SD]) in SP at week 1 was -90 (220), -185 (214), and -271 (265) for placebo, 2%, and 4% glycopyrrolate, respectively. Subjects with higher baseline SP had higher sweat reduction from baseline. Virtual clinical trials were simulated and analyzed using conventional (at the end of the study) versus model-based methods to determine sample size for achieving 80% power to identify a dose-response relationship. Twenty-seven subjects compared with at least 120 subjects would be needed using model-based and conventional methods, respectively. Thus, the model-based method using longitudinal data required fewer subjects than the conventional single-point method.

dExtended-infusion ceftolozane-tazobactam treatment at 1.5 g every 8 h was used to treat multidrug-resistant Pseudomonas aeruginosa in a critically ill patient on continuous venovenous hemofiltration. Serum drug concentrations were measured at 1, 4, 5, 6, and 8 h after the start of infusion. Prefilter levels of ceftolozane produced a maximum concentration of drug (C max ) of 38.57 g/ml, concentration at the end of the dosing interval (C min ) of 31.63 g/ml, time to C max (T max ) of 4 h, area under the concentration-time curve from 0 to 8 h (AUC 0 -8 ) of 284.38 g · h/ml, and a half-life (t 1/2 ) of 30.7 h. The concentrations were eight times the susceptibility breakpoint for the entire dosing interval.

Veliparib (ABT-888) is a novel oral poly-ADP-ribose polymerase (PARP) inhibitor that is being developed for the treatment of hematologic malignancies and solid tumors. Although the pharmacokinetics of veliparib has been studied in combination with cytotoxic agents, limited information exists regarding the pharmacokinetics of chronically-dosed, single-agent veliparib, in patients with either BRCA 1/2–mutated cancer or PARP sensitive tumors. The objectives of the current analysis were to characterize the population pharmacokinetics of veliparib and its primary, active metabolite, M8, and to evaluate the relationship between veliparib and M8 concentrations and poly-ADP-ribose (PAR) level observed in peripheral blood mononuclear cells (PBMC). Seventy-one subjects contributed with veliparib plasma concentrations, M8 plasma concentrations, and PAR levels in PBMC. Veliparib and M8 concentrations were modeled simultaneously using a population PK approach. A two-compartment model with delayed first-order absorption and the elimination parameterized as renal (CLR/F) and non-renal clearance (CLNR/F) adequately described veliparib pharmacokinetics. The pharmacokinetics of the M8 metabolite was described with a two-compartment model. Creatinine clearance and lean body mass were identified as significant predictors of veliparib CLR/F and central volume of distribution, respectively. For a typical subject (LBM, 48 kg; CLCR, 95 mL/min), total clearance (CLR/F +CLNR/F), central and peripheral volume of distribution for veliparib were estimated as 17.3 L/h, 98.7 L and 48.3 L, respectively. At least 50% inhibition of PAR levels in PBMCs was observed at dose levels ranging from 50 to 500 mg.

Purpose Veliparib is an oral inhibitor of poly(ADP-ribose) polymerase enzyme. Combination of veliparib and temozolomide was well-tolerated and demonstrated clinical activity in older patients with relapsed or refractory acute myeloid leukemia (AML) or AML arising from pre-existing myeloid malignancies. We aimed to perform quantitative assessments of pharmacokinetics, efficacy, and safety of veliparib in this patient population to inform future trial design. Methods Population pharmacokinetic analysis was performed using Phoenix® NLME with pharmacokinetic data obtained from 37 subjects after oral administration of veliparib in a Phase I study with and without temozolomide. Effect of covariates (age, sex, BMI, creatinine clearance (CLCR), and co-administration of temozolomide) on the pharmacokinetics of veliparib were evaluated, as well as impact of veliparib exposure on mucositis (dose-limiting toxicity), objective response rate (ORR), and overall survival. Results A two-compartment model with first-order elimination and a first-order absorption with lag-time adequately described veliparib pharmacokinetics. CLCR and body weight were clinically significant covariates for veliparib disposition. The proportion of subjects with all grade mucositis increased with veliparib exposure (AUC). However, no trend in ORR and overall survival was observed with increasing exposure. Conclusions Veliparib with temozolomide presents a promising combination for older patients with myeloid leukemias. An exposure–safety relationship was established for this combination. Further clinical investigations aimed at elucidating the veliparib exposure–efficacy/safety relationship and optimizing dosing recommendations for maximizing benefit–risk in patients with advanced myeloid malignancies should study veliparib doses ranging up to 120 mg in combination with temozolomide.