Akintunde Bello

Multiple-Dose Safety and Pharmacokinetics of Oral Garenoxacin in Healthy Subjects

ABSTRACT Garenoxacin (T-3811ME, BMS-284756) is a novel des-F(6) quinolone that has been shown to be effective in vitro against a wide range of clinically important pathogens, including gram-positive and gram-negative aerobes and anaerobes. This study was conducted to evaluate the safety and tolerability of multiple oral doses (100 to 1,200 mg/day) of garenoxacin in healthy subjects and to determine its multiple-dose pharmacokinetics. Forty healthy male and female subjects (18 to 45 years of age) were enrolled in this randomized, double-blind, placebo-controlled, sequential, multiple- and ascending-dose study. Each subject received a once-daily oral dose of garenoxacin (100, 200, 400, 800, or 1,200 mg) or a placebo for 14 days. Blood and urine samples were collected for measurements of garenoxacin by validated liquid chromatography with dual mass spectrometry, and plasma garenoxacin concentration-time data were analyzed by noncompartmental methods. The effects of garenoxacin on Helicobacter pylori, psychometric test performance, and electrocardiograms were assessed, as was drug safety. Over the 14 days of dosing, geometric mean peak concentrations of garenoxacin in plasma (Cmax) at the 100- and 1,200-mg doses were within the ranges of 1.2 to 1.6 and 16.3 to 24 μg/ml, respectively. The corresponding values for the geometric mean area under the concentration-time curve over the dosing interval (AUCτ) for garenoxacin in plasma at the 100- and 1,200-mg doses were within the ranges of 11.5 to 15.7 and 180 to 307 μg · h/ml, respectively. Increases in systemic exposure to garenoxacin in terms of AUC and Cmax were approximately dose proportional over the 100- to 400-mg dose range but demonstrated increases that were somewhat greater than the dose increments at the 800- and 1,200-mg doses. Median values for the time to achieve Cmax were in the range of 1.13 to 2.50 h for all doses. The mean elimination half-life for garenoxacin in plasma appeared to be independent of dose and ranged from 13.3 to 17.8 h (day 14). Approximately 30 to 50% of an administered garenoxacin dose was excreted unchanged in the urine. At doses of 100 to 400 mg, steady-state concentrations of garenoxacin in plasma appeared to be attained by the fourth dose. Multiple oral doses of garenoxacin were well tolerated and did not demonstrate clinically significant effects on QTc or psychometric test results. Garenoxacin administered alone for 14 days at doses of ≥400 mg demonstrated activity against H. pylori. These results suggest that multiple once-daily oral doses of garenoxacin of up to 1,200 mg are safe and well tolerated and that the pharmacokinetics of garenoxacin support once-daily administration.

Population Pharmacokinetics and Pharmacodynamics of Garenoxacin in Patients with Community-Acquired Respiratory Tract Infections

ABSTRACT Garenoxacin (T-3811ME, BMS-284756) is a novel, broad-spectrum des-F(6) quinolone currently under study for the treatment of community-acquired respiratory tract infections. This analysis assessed garenoxacin population pharmacokinetics and exposure-response relationships for safety (adverse effects [AE]) and antimicrobial activity (clinical cure and bacteriologic eradication of Streptococcus pneumoniae and the grouping of Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis). Data were obtained from three phase II clinical trials of garenoxacin administered orally as 400 mg once daily for 5 to 10 days for the treatment of community-acquired pneumonia, acute exacerbation of chronic bronchitis, and sinusitis. Samples were taken from each patient before drug administration, 2 h following administration of the first dose, and on the day 3 to 5 visit. Individual Bayesian estimates of the fu (fraction unbound), the Cmax, and the fu for the area under the concentration-time curve from 0 to 24 h (fu AUC0-24) were calculated as measurements of drug exposure by using an ex vivo assessment of average protein binding. Regression analysis was performed to examine the following relationships: treatment-emergent AE incidence and AUC0-24, Cmax, or patient factors; clinical response or bacterial eradication and drug exposure (fu Cmax/MIC, fu AUC0-24/MIC, and other exposure covariates); or disease and patient factors. Garenoxacin pharmacokinetics were described by a one-compartment model with first-order absorption and elimination. Clearance was dependent on creatinine clearance, ideal body weight, age, obesity, and concomitant use of pseudoephedrine. The volume of distribution was dependent on weight and gender. Patients with mild or moderate renal dysfunction had, on average, approximately a 16 or 26% decrease in clearance, respectively, compared to patients of the same gender and obesity classification with normal renal function. AE occurrence was not related to garenoxacin exposure. Overall, clinical cure and bacterial eradication rates were 91 and 90%, respectively, for S. pneumoniae and 93 and 92%, respectively, for the grouping of H. influenzae, H. parainfluenzae, and M. catarrhalis. The fu AUC0-24/MIC ratios were high (>90% were >200), and none of the pharmacokinetic-pharmacodynamic exposure measurements indexed to the MIC or other factors were significant predictors of clinical or bacteriologic response. Garenoxacin clearance was primarily related to creatinine clearance and ideal body weight. Although garenoxacin exposure was approximately 25% higher for patients with moderate renal dysfunction, this increase does not appear to be clinically significant as exposures in this patient population were not significant predictors of AE occurrence. Garenoxacin exposures were at the upper end of the exposure-response curves for measurements of antimicrobial activity, suggesting that 400 mg of garenoxacin once daily is a safe and adequate dose for the treatment of the specified community-acquired respiratory tract infections.

Effects of the Des-F(6)-Quinolone Garenoxacin (BMS-284756), in Comparison to Those of Ciprofloxacin and Ofloxacin, on Joint Cartilage in Immature Rats

ABSTRACT We did not observe signs of chondrotoxicity in immature rats treated orally with garenoxacin (BMS-284756) at doses up to five times 600 mg/kg of body weight or with ciprofloxacin, whereas ofloxacin induced typical cartilage lesions. The peak plasma garenoxacin concentration was 25.5 mg/liter after administration of a dose of 600 mg/kg once daily for 5 days. Assuming that this model is predictive of human risk, BMS-284756 and ciprofloxacin should be more suitable for pediatric use than ofloxacin.

Assessment of nivolumab benefit–risk profile of a 240-mg flat dose relative to a 3-mg/kg dosing regimen in patients with advanced tumors

Abstract Background Nivolumab 3 mg/kg every 2 weeks (Q2W) has shown benefit versus the standard of care in melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC). However, flat dosing is expected to shorten preparation time and improve ease of administration. With knowledge of nivolumab safety, efficacy, and pharmacokinetics across a wide dose range in body weight (BW) dosing, assessment of the benefit–risk profile of a 240-mg flat dose relative to the approved 3-mg/kg dose was approached by quantitative clinical pharmacology. Patients and methods A flat dose of 240 mg was selected based on its equivalence to the 3-mg/kg dose at the median BW of ∼80 kg in patients in the nivolumab program. The benefit–risk profile of nivolumab 240 mg was evaluated by comparing exposures at 3 mg/kg Q2W and 240 mg Q2W across BW and tumor types; clinical safety at 3 mg/kg Q2W by BW and exposure quartiles in melanoma, NSCLC, and RCC; and safety and efficacy at 240 mg Q2W relative to 3 mg/kg Q2W in melanoma, NSCLC, and RCC. Results The median nivolumab exposure and its distribution at 240 mg Q2W were similar to 3 mg/kg Q2W in the simulated population. Safety analyses did not demonstrate a clinically meaningful relationship between BW or nivolumab exposure quartiles and frequency or severity of adverse events. The predicted safety and efficacy were similar across nivolumab exposure ranges achieved with 3 mg/kg Q2W or 240 mg Q2W flat dose. Conclusion Based on population pharmacokinetic modeling, established flat exposure–response relationships for efficacy and safety, and clinical safety, the benefit–risk profile of nivolumab 240 mg Q2W was comparable to 3 mg/kg Q2W. The quantitative clinical pharmacology approach provided evidence for regulatory decision-making on dose modification, obviating the need for an independent clinical study.

Best practices for the use of itraconazole as a replacement for ketoconazole in drug–drug interaction studies

Ketoconazole has been widely used as a strong cytochrome P450 (CYP) 3A (CYP3A) inhibitor in drug–drug interaction (DDI) studies. However, the US Food and Drug Administration has recommended limiting the use of ketoconazole to cases in which no alternative therapies exist, and the European Medicines Agency has recommended the suspension of its marketing authorizations because of the potential for serious safety concerns. In this review, the Innovation and Quality in Pharmaceutical Developments Clinical Pharmacology Leadership Group (CPLG) provides a compelling rationale for the use of itraconazole as a replacement for ketoconazole in clinical DDI studies and provides recommendations on the best practices for the use of itraconazole in such studies. Various factors considered in the recommendations include the choice of itraconazole dosage form, administration in the fasted or fed state, the dose and duration of itraconazole administration, the timing of substrate and itraconazole coadministration, and measurement of itraconazole and metabolite plasma concentrations, among others. The CPLGs recommendations are based on careful review of available literature and internal industry experiences.

Effect of a High-Fat Meal on the Pharmacokinetics of the Des-F(6)-Quinolone BMS-284756

Study Objective. To evaluate the effects of a high‐fat meal on the systemic exposure of oral BMS‐284756.

Clinical Pharmacology Considerations for the Development of Immune Checkpoint Inhibitors

Immuno‐oncology works through activation of the patients immune system against cancer, with several advantages over other treatment approaches, including cytotoxic agents and molecular‐targeted therapies. The most notable feature of immuno‐oncology treatments is the nature of the patient responses achieved, which can be more durable and sustained than with other modalities. Increased understanding of immune system complexity has provided a number of opportunities to advance several strategies for the development of immuno‐oncology therapies. This review outlines the clinical pharmacology characteristics and development challenges for the 6 approved immunomodulatory monoclonal antibodies that target 2 immune checkpoint pathways: ipilimumab (an anti–cytotoxic T‐lymphocyte antigen‐4 antibody) and, more recently, nivolumab and pembrolizumab (both anti–programmed death‐1 antibodies) and atezolizumab, avelumab, and durvalumab (all anti–programmed death ligand‐1 antibodies). These agents have revealed much about the clinical pharmacology features of immune checkpoint inhibitors as a class, as well as the pharmacometric approaches used to support their clinical development and regulatory approval. The development experiences with these pioneering immuno‐oncology agents are likely to serve as useful guides in the discovery, progression, and approval of future drugs or combination of drugs in this class. This review includes summaries of the pharmacokinetics and exposure–response of the immune checkpoint inhibitors approved to date, as well as an overview of some quantitative systems pharmacology approaches. The ability of immuno‐oncology to meet its full potential will depend on overcoming development challenges, including the need for clear strategies to determine optimal dose and scheduling for monotherapy as well as combination approaches.

Nivolumab Exposure–Response Analyses of Efficacy and Safety in Previously Treated Squamous or Nonsquamous Non–Small Cell Lung Cancer

Purpose: Nivolumab is a fully human IgG4 monoclonal antiprogrammed death-1 antibody with demonstrated efficacy, including durable responses and prolonged survival, in patients with previously treated, advanced non–small cell lung cancer (NSCLC). Exposure–response (E–R) analyses for efficacy and safety were conducted to inform the benefit–risk assessment of nivolumab in this patient population. Experimental Design: The analyses used clinical trial data from patients with squamous (n = 293) or nonsquamous (n = 354) NSCLC from four clinical trials who received nivolumab doses of 1 to 10 mg/kg every 2 weeks. E–R efficacy analyses were performed by investigating the relationship between time-averaged nivolumab concentration after the first dose (Cavg1) and the probability of overall survival by histology. E–R safety analyses examined relationships between nivolumab Cavg1 and hazards of adverse events leading to discontinuation or death (AEs-DC/D). Results: Nivolumab exposure was not associated with overall survival [the 95% confidence interval (CI) of effect included 1] in patients with squamous (HR, 0.802; 95% CI, 0.555–1.16) or nonsquamous NSCLC (HR, 0.94; 95% CI, 0.683–1.29). Similarly, nivolumab exposure was not associated with AEs-DC/D in the overall population (HR, 0.917; 95% CI, 0.644–1.31). The risk of AEs-DC/D was similar among patients with squamous or nonsquamous histology. Conclusions: Nivolumab monotherapy demonstrated a wide therapeutic margin, as evidenced by relatively flat E–R relationships over the range of exposures produced by doses of 1 to 10 mg/kg every 2 weeks (Q2W), supporting the use of the initially approved dose of 3 mg/kg Q2W in patients with NSCLC. Clin Cancer Res; 23(18); 5394–405. ©2017 AACR.

Improving the tools of clinical pharmacology: Goals for 2017 and beyond

Current trends in pronounced late‐stage attrition rates of promising drug candidates are a pressing concern for patients, providers, and other stakeholders across the health care system. Here, we describe six areas in which clinical pharmacology methods and frameworks can help ameliorate these trends in late‐stage attrition and increase the efficiency of drug development and evaluation. These recommendations are based, in part, on previous stakeholder engagement and input, as well as a previously published white paper.

Characterization of the penetration of garenoxacin into the breast milk of lactating women.

The primary objective of this study was to characterize the extent of excretion of garenoxacin, a novel des‐F(6)‐quinolone antimicrobial, into the breast milk of lactating women. A secondary objective was to determine the time after dose administration that garenoxacin was no longer detected in breast milk so as to define when a mother may resume breastfeeding if it was interrupted for garenoxacin administration. Six healthy, lactating women (age [mean ± SD]: 32 ± 6 years; weight: 68.3 ± 19.8 kg; body mass index: 26 ± 5 kg/m2) who had completed weaning their infants were administered a single 600‐mg oral dose of garenoxacin. Plasma samples were collected predose and repeatedly up to 72 hours postdose. Breast milk was collected predose and for 6‐ to 12‐hour intervals repeatedly up to 120 hours postdose. Breast milk/plasma concentration ratios for garenoxacin ranged from 0.35 to 0.44 up to 24 hours postdose, and the mean peak breast milk concentration was 3.0 μg/mL (0‐ to 6‐h collection interval). Overall, garenoxacin exposure in breast milk was minimal, with a mean of 0.07% of the administered dose recovered within 120 hours. Indeed, garenoxacin was undetectable in the breast milk of a majority of subjects within 84 hours of dosing. As such, an infant nursing from a mother who had received a single 600‐mg oral dose of garenoxacin could theoretically be exposed to 0.42 mg of garenoxacin (0.105 mg/kg/day for a 4‐kg infant over the period of 5 days of nursing). If extrapolated to a 14‐day course of garenoxacin 600 mg once daily, total exposure would be approximately 5.88 mg. These findings indicate that, like other quinolone antimicrobials, garenoxacin is secreted in breast milk.