Migraine therapeutics in adolescents: a systematic analysis and historic perspectives of triptan trials in adolescents.

OBJECTIVES To conduct a systematic review and analysis of trial data submitted to the US Food and Drug Administration (FDA) to identify possible causes for the failure of pediatric trials of triptans for treatment of migraines. DATA SOURCE The FDA website for drug information and published literature. STUDY SELECTION All pediatric efficacy and pharmacokinetics trial data of drugs used for abortive treatment of migraine submitted to the FDA from January 1, 1999, through December 31, 2011. MAIN OUTCOME MEASURES Patient demographic baseline characteristics, inclusion and exclusion criteria, trial designs, efficacy end points, and pharmacokinetic profiles were analyzed and compared across drug products. RESULTS We analyzed data for sumatriptan succinate nasal spray and zolmitriptan, eletriptan hydrobromide, almotriptan malate, and rizatriptan benzoate tablets. Seven efficacy trials had a randomized, double-blinded, placebo-controlled, parallel-group trial design. In 4 trials, patients were required to have a history of migraine attacks lasting at least 4 hours. High response rates for placebo were observed in all trials, with pain relief at 2 hours ranging from 53% to 57.5%. Nonrandomization of patients with an early placebo response design was used in the rizatriptan trial in 2011. Compared with the rizatriptan trial conducted in 1999, the 2011 rizatriptan trial reduced the placebo response rate by 6% for headache freedom at the 2-hour posttreatment end point owing to study design. The pharmacokinetic profiles between adolescents and adults were statistically similar. CONCLUSIONS High placebo response rates are consistent across all trials and may represent the principal challenge in pediatric trials of drugs for abortive treatment of migraine. Enrichment with selection of subjects with long-lasting migraine attacks is not sufficient to overcome high placebo response rates. Another enrichment strategy, the nonrandomization of patients with an early placebo response, successfully reduces the high placebo response rate for rizatriptan and is a trial design that should be considered for future pediatric trials of abortive migraine therapeutics.

Geriatric drug evaluation: where are we now and where should we be in the future?

The older population is currently the fastest growing age group in the United States, and this trend is expected to continue for several decades. Older individuals, in general, have a higher disease burden compared with younger adults and are the major users of medications, yet premarketing drug clinical trials have often excluded them even for the drugs that have high utility in this age group. Extrapolation of clinical results from younger to older individuals does not provide adequate benefit-risk estimation, and the frequent need for dose adjustment in older patients from initially approved doses exemplifies the current lack of adequate clinical data in the elderly. Herein, we discuss the information gap for older individuals and the need for a better understanding of the effect of aging on drug responses. We also present cases for future directions, urging the implementation of improved clinical trial designs using new and emerging pharmacokinetic and pharmacodynamic methods to allow the provision of evidence-based individualized treatment to this high drug use group.

Improving pediatric dosing through pediatric initiatives: what we have learned.

OBJECTIVE: The goal was to review the impact of pediatric drug studies, as measured by the improvement in pediatric dosing and other pertinent information captured in the drug labeling. METHODS: We reviewed the pediatric studies for 108 products submitted (July 1998 through October 2005) in response to a Food and Drug Administration written request for pediatric studies, and the subsequent labeling changes. We analyzed the dosing modifications and focused on drug clearance as an important parameter influencing pediatric dosing. RESULTS: The first 108 drugs with new or revised pediatric labeling changes had dosing changes or pharmacokinetic information (n = 23), new safety information (n = 34), information concerning lack of efficacy (n = 19), new pediatric formulations (n = 12), and extended age limits (n = 77). A product might have had > or = 1 labeling change. We selected specific examples (n = 16) that illustrate significant differences in pediatric pharmacokinetics. CONCLUSIONS: Critical changes in drug labeling for pediatric patients illustrate that unique pediatric dosing often is necessary, reflecting growth and maturational stages of pediatric patients. These changes provide evidence that pediatric dosing should not be determined by simply applying weight-based calculations to the adult dose. Drug clearance is highly variable in the pediatric population and is not readily predictable on the basis of adult information.

Impact of pharmacometrics on drug approval and labeling decisions: a survey of 42 new drug applications.

The value of quantitative thinking in drug development and regulatory review is increasingly being appreciated. Modeling and simulation of data pertaining to pharmacokinetic, pharmacodynamic, and disease progression is often referred to as the pharmacometrics analyses. The objective of the current report is to assess the role of pharmacometrics at the US Food and Drug Administration (FDA) in making drug approval and labeling decisions. The New Drug Applications (NDAs) submitted between 2000 and 2004 to the Cardio-renal, Oncology, and Neuropharmacology drug products divisions were surveyed. For those NDA reviews that included a pharmacometrics consultation, the clinical pharmacology scientists ranked the impact on the regulatory decision(s). Of about a total of 244 NDAs, 42 included a pharmacometrics component. Review of NDAs involved independent, quantitative evaluation by FDA pharmacometricians, even when such analysis was not conducted by the sponsor. Pharmacometric analyses were pivotal in regulatory decision making in more than half of the 42 NDAs. Of the 14 reviews that were pivotal to approval related decisions, 5 identified the need for additional trials, whereas 6 reduced the burden of conducting additional trials. Collaboration among the FDA clinical pharmacology, medical, and statistical reviewers and effective communication with the sponsors was critical for the impact to occur. The survey and the case studies emphasize the need for early interaction between the FDA and sponsors to plan the development more efficiently by appreciating the regulatory expectations better.