A Comparative Review of Waivers Granted in Pediatric Drug Development by FDA and EMA from 2007-2013.

BACKGROUND: The European Union and the United States have different legal frameworks in place for pediatric drug development, which can potentially lead to different pediatric research requirements for the pharmaceutical industry. This manuscript compares pediatric clinical trial waivers granted by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). METHODS: This is a retrospective review comparing EMA's Paediatric Committee (PDCO) decisions with FDA's Pediatric Review Committee (PeRC) recommendations for all product-specific pediatric full waiver applications submitted to EMA from January 2007 through December 2013. Using baseline data from EMA, we matched product-specific waivers with their FDA equivalents during the study period. RESULTS: For single active substance products, PDCO and PeRC adopted similar opinions in 42 of 49 indications (86%). For fixed-dose combinations, PDCO and PeRC adopted similar opinions in 24 of 31 indications (77%). CONCLUSION: Despite the different legal frameworks, criteria, and processes of determination, the waiver decisions of the 2 agencies were similar in the majority of cases.

Impact of pediatric exclusivity on drug labeling and demonstrations of efficacy.

BACKGROUND: Besides vaccines and otitis media medicines, most products prescribed for children have not been studied in the pediatric population. To remedy this, Congress enacted legislation in 1997, known as pediatric exclusivity (PE), which provides 6 months of additional market protection to drug sponsors in exchange for studying their products in children. METHODS: We reviewed requests for pediatric studies and subsequent labeling for drugs granted PE from 1998 through 2012. Regression analysis estimates the probability of demonstrating efficacy in PE trials. Variables include therapeutic group, year of exclusivity, product sales, initiation process, and small disease population. RESULTS: From 1998 through 2012, the US Food and Drug Administration issued 401 pediatric study requests. For 189 drugs, studies were completed and granted exclusivity. A total of 173 drugs (92%) received new pediatric labeling, with 108 (57%) receiving a new or expanded pediatric indication. Three drugs had non-efficacy trials. Efficacy was not established for 78 drugs. Oncology, cardiovascular, and endocrine drugs were less likely to demonstrate efficacy (P < .01) compared with gastrointestinal and pain/anesthesia drugs. Drugs studied later in the program were less likely to demonstrate efficacy (P < .05). Sales, initiation process, and small disease population were not significant predictors. CONCLUSIONS: Most drugs (173; 92%) granted exclusivity added pediatric information to their labeling as a result of PE, with 108 (57%) receiving a new or expanded pediatric indication. Therapeutic area and year of exclusivity influenced the likelihood of obtaining a pediatric indication. Positive and negative outcomes continue to inform the construct of future pediatric trials.

The globalization of pediatric clinical trials.

OBJECTIVE: To examine the characteristics of pediatric trials conducted under US legislation and to compare results with data from 2002 to 2007. METHODS: We reviewed all pediatric trials provided to the US Food and Drug Administration in submissions that were approved between September 28, 2007 and December 21, 2010. We extracted data for each trial including age range, therapeutic indication, design, duration, and patient and center enrollment by location. RESULTS: Overall 346 studies on 113 drugs and biologicals enrolled 55 819 pediatric patients. The United States participated in 86% of the studies, providing 71% of the centers and 74% of the patients. Corresponding percentages for non-US countries were 43%, 29%, and 26% respectively. Developing or transition countries participated in 22% of the studies, providing 12% of the centers and 10% of the patients; our earlier analysis found corresponding percentages of 38%, 12%, and 23%. The most common therapeutic areas studied in the latter countries were infectious, neurologic, and pulmonary diseases. Seventy-eight vaccine studies enrolled 147 692 patients. The United States participated in 40% of the studies, providing 39% of the centers and 22% of the patients. Corresponding percentages for non-US countries were 74%, 61%, and 78% respectively. Developing or transition countries participated in 27% of the studies, providing 15% of the centers and 52% of the patients. CONCLUSIONS: The United States remains an important location for pediatric trials. Developing country involvement in pediatric drug development is not increasing, although these countries participate significantly in vaccine trials.

Extrapolation of adult data and other data in pediatric drug-development programs.

OBJECTIVES: In 1994, the US Food and Drug Administration (FDA) proposed an approach, based on extrapolation of efficacy findings from adults to the pediatric population, to maximize the use of adult data and other data when designing pediatric drug-development programs. We examined the experience of the FDA in using extrapolation to evaluate how and when it was used and any changes in scientific assumptions over time. METHODS: We reviewed 370 pediatric studies submitted to the FDA between 1998 and 2008 in response to 159 written requests (166 products) issued under the Pediatric Exclusivity Provision. We identified cases in which efficacy was extrapolated from adult data or other data, we categorized the type of pediatric data required to support extrapolation, and we determined whether the data resulted in new pediatric labeling. RESULTS: Extrapolation of efficacy from adult data occurred for 82.5% of the drug products (137 of 166). Extrapolation was defined as complete for 14.5% of the products (24 of 166) and partial for 68% of them (113 of 166). Approaches to extrapolation changed over time for 19% of the therapeutic indications studied (13 of 67). When extrapolation was used, 61% of the drug products (84 of 137) obtained a new pediatric indication or extension into a new age group; this number decreased to 34% (10 of 29) when there was no extrapolation. CONCLUSIONS: Extrapolating efficacy from adult data or other data to the pediatric population can streamline pediatric drug development and help to increase the number of approvals for pediatric use.

Safety and transparency of pediatric drug trials.

OBJECTIVES: To quantify the frequency and type of new safety information arising from studies performed under the auspices of the Pediatric Exclusivity Program, to describe the dissemination of these findings in the peer-reviewed literature and compare this with the US Food and Drug Administration (FDA) review, and to describe their effect on pediatric labeling. DESIGN: Cohort study of the 365 trials performed for 153 drugs. SETTING: The Pediatric Exclusivity incentive from December 1997 through September 2007. PARTICIPANTS: Food and Drug Administration publicly available records and peer-reviewed literature retrievable by MEDLINE search. Main Exposures New safety findings obtained from the trials completed for exclusivity. OUTCOME MEASURES: Concordance of the information highlighted in the peer-reviewed article abstracts with the information in the FDA labeling and drug reviews. RESULTS: There were 137 labeling changes; we evaluated 129 of these (the 8 selective serotonin reuptake inhibitors were excluded from review). Thirty-three products (26%) had pediatric safety information added to the labeling. Of these, 12 products had neuropsychiatric safety findings and 21 had other important safety findings. Only 16 of 33 of these trials (48%) were reported in the peer-reviewed literature; however, 7 of 16 focused on findings substantively different from those highlighted in the FDA reviews and labeling changes. CONCLUSIONS: Medication adverse events in children often differ from those in adults, particularly those that are neuropsychiatric in nature. Labeling changes for pediatric use demonstrate that pediatric drug studies provide valuable and unique safety data that can guide the use of these drugs in children. Unfortunately, most of these articles are not published, and almost half of the published articles focus their attention away from the crucial safety data.

The economic returns of pediatric clinical trials of antihypertensive drugs.

BACKGROUND: Congress has authorized the United States Food and Drug Administration (FDA) to provide industry sponsors with a 6-month extension of drug marketing rights under the Pediatric Exclusivity Provision if FDA-requested pediatric drug trials are conducted. The cost and economic return of pediatric exclusivity to industry sponsors has been shown to be highly variable. We sought to determine the cost of performing pediatric exclusivity trials within a single therapeutic area and the subsequent economic return to industry sponsors. METHODS: We evaluated 9 orally administered antihypertensive drugs submitted to the FDA under the Pediatric Exclusivity Provision from 1997 to 2004 and obtained key elements of the clinical trial designs and operations. Estimates of the costs of performing the studies were generated and converted into after-tax cash outflow. Market sales were obtained and converted into after-tax inflows based on 6 months of additional patent protection. Net economic return and net return-to-cost ratios were determined for each drug. RESULTS: Of the 9 antihypertensive agents studied, an average of 2 studies per drug was performed, including at least 1 pharmacokinetic study and a safety and efficacy study. The median cost of completing a pharmacokinetic trial was $862,000 (range $556,000 to 1.8 million). The median cost of performing safety and efficacy trials for these agents was $4.3 million (range $2.1-12.9 million). The ratio of net economic return to cost was 17 (range 4-64.7). CONCLUSION: We found that, within a cohort of antihypertensive drugs, the Pediatric Exclusivity Provision has generated highly variable, yet lucrative returns to industry sponsors.

Safety monitoring of drugs receiving pediatric marketing exclusivity.

OBJECTIVES: The Food and Drug Administration Modernization Act provided for an additional 6-month period of marketing exclusivity to companies that perform pediatric drug trials in response to a Food and Drug Administration-issued written request. Because many safety concerns cannot be detected until after the introduction of a product to a larger and more diverse market, the Best Pharmaceuticals for Children Act required the Food and Drug Administration to report to the Pediatric Advisory Committee on adverse events occurring during the 1-year period after granting pediatric exclusivity. We sought to describe the Pediatric Advisory Committee's recommendations made in response to safety reviews informed by data from the Food and Drug Administration Adverse Event Reporting System in 67 drugs granted exclusivity. PATIENTS AND METHODS: Pediatric Advisory Committee meetings and data presented by the Food and Drug Administration for all drugs were reviewed from June 2003 through April 2007. We divided the drugs into 2 groups: those that were returned to routine adverse event monitoring and those that had specific Pediatric Advisory Committee recommendations. RESULTS: Forty-four (65.7%) drugs were returned to routine monitoring for adverse events. The Pediatric Advisory Committee, sometimes working with other advisory committees, recommended label changes for 12 (17.9%) drugs, continued monitoring for 10 (14.9%), production of MedGuides for 9 (13.4%), and an update on label changes resulting from discussions with the sponsor for 1 (1.5%) drug. Some drugs had >1 action. Several of the adverse events revealed during this process were rare and life-threatening. CONCLUSIONS: Safety monitoring during the early postmarketing period is crucial to detect rare, serious, or pediatric-specific adverse events. Fortunately, the majority of drugs given exclusivity had no adverse events of a frequency or severity that prevented a return to routine adverse event monitoring.

Pediatric antihypertensive trial failures: analysis of end points and dose range.

Historically, drugs prescribed for children have not been studied in pediatric populations. Since 1997, however, a 6-month extension of marketing rights is granted if manufacturers conduct Food and Drug Administration-defined pediatric trials. In nearly half of the drugs studied, there were unexpected results in dosing, safety, or efficacy compared with adult studies, including failure of half of the antihypertensive dose-response trials, which are pivotal for deriving dosing recommendations. We sought to define design elements that might have contributed to these trial failures by combining patient-level data from 6 dose-ranging antihypertensive efficacy trials completed for pediatric exclusivity and submitted to the Food and Drug Administration from 1998 to 2005. We evaluated dosing, primary end point, and other components to assess underlying reasons for failure to show efficacy in children. Of 6 trials examined, 3 showed a dose response; 3 did not. Eligibility criteria were similar across studies, as were subject demographics. Successful studies showed large differences in doses, with little or no overlap between low, medium, and high doses; failed trials used narrow dose ranges with considerable overlap. Successful trials also provided pediatric formulations and used reduction in diastolic, not systolic, blood pressure as the primary end point. Careful attention to pediatric pharmacology and selection of primary end points can improve trial performance. We found poor dose selection, lack of acknowledgement of differences between adult and pediatric populations, and lack of pediatric formulations to be associated with failures. More importantly, our ability to combine data across trials allowed us to evaluate and potentially improve trial design.

Safety of placebo controls in pediatric hypertension trials.

Many clinical trials, including those in pediatric populations, use a placebo arm for medical conditions for which there are readily available therapeutic interventions. Several short-term efficacy trials of antihypertensive medications performed in response to Food and Drug Administration-issued written requests have used a placebo arm; whether the use of a placebo arm is safe in children with hypertension is unknown. We sought to define the rates of adverse events in 10 short-term antihypertensive trials to determine whether these trials resulted in increased risk to pediatric patients receiving placebo. We combined patient-level data from 10 antihypertensive efficacy trials performed in pediatric patients that were submitted to the Food and Drug Administration from 1998 to 2005. We determined the number and type of all of the adverse events reported during the placebo-controlled portion of the clinical trials and compared these numbers between the patients who received placebo and those who received active drug. Among the 1707 children in the 10 studies, we observed no differences in the rates of adverse events reported between the patients who received placebo and those who received active drug. Only 5 patients suffered a serious adverse event during the trials; none were thought by the investigators to be related to study drug, and only 1 occurred in a patient receiving placebo. Short-term exposure to placebo in pediatric trials of antihypertensive medications appears to be safe.

Economic return of clinical trials performed under the pediatric exclusivity program.

CONTEXT: In 1997, Congress authorized the US Food and Drug Administration (FDA) to grant 6-month extensions of marketing rights through the Pediatric Exclusivity Program if industry sponsors complete FDA-requested pediatric trials. The program has been praised for creating incentives for studies in children and has been criticized as a "windfall" to the innovator drug industry. This critique has been a substantial part of congressional debate on the program, which is due to expire in 2007. OBJECTIVE: To quantify the economic return to industry for completing pediatric exclusivity trials. DESIGN AND SETTING: A cohort study of programs conducted for pediatric exclusivity. Nine drugs that were granted pediatric exclusivity were selected. From the final study reports submitted to the FDA (2002-2004), key elements of the clinical trial design and study operations were obtained, and the cost of performing each study was estimated and converted into estimates of after-tax cash outflows. Three-year market sales were obtained and converted into estimates of after-tax cash inflows based on 6 months of additional market protection. Net economic return (cash inflows minus outflows) and net return-to-costs ratio (net economic return divided by cash outflows) for each product were then calculated. MAIN OUTCOME MEASURES: Net economic return and net return-to-cost ratio. RESULTS: The indications studied reflect a broad representation of the program: asthma, tumors, attention-deficit/hyperactivity disorder, hypertension, depression/generalized anxiety disorder, diabetes mellitus, gastroesophageal reflux, bacterial infection, and bone mineralization. The distribution of net economic return for 6 months of exclusivity varied substantially among products (net economic return ranged from -$8.9 million to $507.9 million and net return-to-cost ratio ranged from -0.68 to 73.63). CONCLUSIONS: The economic return for pediatric exclusivity is variable. As an incentive to complete much-needed clinical trials in children, pediatric exclusivity can generate lucrative returns or produce more modest returns on investment.

Peer-reviewed publication of clinical trials completed for pediatric exclusivity.

CONTEXT: Much of pediatric drug use is off-label because appropriate pediatric studies have not been conducted and the drugs have not been labeled by the US Food and Drug Administration (FDA) for use in children. In 1997, Congress authorized the FDA to grant extensions of marketing rights known as "pediatric exclusivity" if FDA-requested pediatric trials were conducted. As a result, there have been over 100 product labeling changes. The publication status of studies completed for pediatric exclusivity has not been evaluated. OBJECTIVE: To quantify the dissemination of results of studies conducted for pediatric exclusivity into the peer-review literature. DESIGN: Cohort study of all trials conducted for pediatric exclusivity between 1998 and 2004 as determined by MEDLINE and EMBASE searches through 2005, the subsequent labeling changes, and the publication of those studies in peer-reviewed journals. We categorized any labeling changes resulting from the studies as positive or negative for the drug under study. We then evaluated aspects of the studies and product label changes that were associated with subsequent publication in peer-reviewed medical journals. MAIN OUTCOME MEASURES: Publication of the trial data in peer-reviewed journals. RESULTS: Between 1998 and 2004, 253 studies were submitted to the FDA for pediatric exclusivity: 125 (50%) evaluated efficacy, 51 (20%) were multi-dose pharmacokinetic, 34 (13%) were single-dose pharmacokinetic, and 43 (17%) were safety studies. Labeling changes were positive for 127/253 (50%) of studies; only 113/253 (45%) were published. Efficacy studies and those with a positive labeling change were more likely to be published. CONCLUSIONS: The pediatric exclusivity program has been successful in encouraging drug studies in children. However, the dissemination of these results in the peer-reviewed literature is limited. Mechanisms to more widely disperse this information through publication warrant further evaluation.