William Rodriguez

Surveillance of Clinical Isolates of Respiratory Syncytial Virus for Palivizumab (Synagis)–Resistant Mutants

Premature infants and those with chronic lung disease or congenital heart disease are at high risk of severe respiratory syncytial virus (RSV) disease. Palivizumab (Synagis), a humanized anti-RSV monoclonal antibody, has been used extensively since 1998 to prevent severe RSV disease in high-risk infants. To monitor for possible palivizumab-resistant mutants, an immunofluorescence binding assay that predicts palivizumab neutralization of RSV was developed. RSV isolates were collected at 8 US sites from 458 infants hospitalized for RSV disease (1998-2002). Palivizumab bound to all 371 RSV isolates able to be evaluated, including 25 from active-palivizumab recipients. The palivizumab epitope appears to be highly conserved, even in infants receiving prophylaxis with palivizumab.

Drug Labeling and Exposure in Neonates

IMPORTANCEnFederal legislation has led to a notable increase in pediatric studies submitted to the Food and Drug Administration (FDA), resulting in new pediatric information in product labeling. However, approximately 50% of drug labels still have insufficient information on safety, efficacy, or dosing in children. Neonatal information in labeling is even scarcer because neonates comprise a vulnerable subpopulation for which end-point development is lagging and studies are more challenging.nnnOBJECTIVEnTo quantify progress made in neonatal studies and neonatal information in product labeling as a result of recent legislation.nnnDESIGN, SETTING, AND PARTICIPANTSnWe identified a cohort of drug studies between 1997 and 2010 that included neonates as a result of pediatric legislation using information available on the FDA website. We determined what studies were published in the medical literature, the legislation responsible for the studies, and the resulting neonatal labeling changes. We then examined the use of these drugs in a cohort of neonates admitted to 290 neonatal intensive care units (NICUs) (the Pediatrix Data Warehouse) in the United States from 2005 to 2010.nnnEXPOSUREnInfants exposed to a drug studied in neonates as identified by the FDA website.nnnMAIN OUTCOMES AND MEASURESnNumber of drug studies with neonates and rate of exposure per 1000 admissions among infants admitted to an NICU.nnnRESULTSnIn a review of the FDA databases, we identified 28 drugs studied in neonates and 24 related labeling changes. Forty-one studies encompassed the 28 drugs, and 31 (76%) of these were published. Eleven (46%) of the 24 neonatal labeling changes established safety and effectiveness. In a review of a cohort of 446,335 hospitalized infants, we identified 399 drugs used and 1,525,739 drug exposures in the first 28 postnatal days. Thirteen (46%) of the 28 drugs studied in neonates were not used in NICUs; 8 (29%) were used in fewer than 60 neonates. Of the drugs studied, ranitidine was used most often (15,627 neonates, 35 exposures per 1000 admissions).nnnCONCLUSIONS AND RELEVANCEnFew drug labeling changes made under pediatric legislation include neonates. Most drugs studied are either not used or rarely used in US NICUs. Strategies to increase the study of safe and effective drugs for neonates are needed.

Safety and Transparency of Pediatric Drug Trials

OBJECTIVESnTo 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.nnnDESIGNnCohort study of the 365 trials performed for 153 drugs.nnnSETTINGnThe Pediatric Exclusivity incentive from December 1997 through September 2007.nnnPARTICIPANTSnFood 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.nnnOUTCOME MEASURESnConcordance of the information highlighted in the peer-reviewed article abstracts with the information in the FDA labeling and drug reviews.nnnRESULTSnThere 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.nnnCONCLUSIONSnMedication 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.

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.

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.

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 Committees 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.

ACR Appropriateness Criteria ® on Developmental Dysplasia of the Hip—Child

Developmental dysplasia of the hip (DDH) affects 1.5 of every 1,000 caucasian Americans and less frequently affects African Americans. Developmental dysplasia of the hip comprises a spectrum of abnormalities, ranging from laxity of the joint and mild subluxation to fixed dislocation. Early diagnosis of DDH usually leads to low-risk treatment with a harness. Late diagnosis of DDH in children may lead to increased surgical intervention and complications. Late diagnosis of DDH in adults can result in debilitating end-stage degenerative hip joint disease. Screening decreases the incidence of late diagnosis of DDH. Clinical evaluation for DDH should be performed periodically at each well-baby visit until the age of 12 months. There is no consensus on imaging screening for DDH. Consideration for screening with ultrasound is balanced between the benefits of early detection of DDH and the increased treatment and cost factors. In addition, randomized trials evaluating primary ultrasound screening did not find significant decrease in late diagnosis of DDH. In the United States, hip ultrasound is selectively performed in infants with risk factors, such as family history of DDH, breech presentation, and inconclusive findings on physical examination. Ultrasound for DDH should be performed after 2 weeks of age because laxity is common after birth and often resolves itself. A pelvic radiograph can optimally be performed after the age of 4 months, when most infants will have ossification centers of the femoral heads.

Adverse Drug Events in Children: The US Food and Drug Administration Perspective

Abstract Background: Adverse events are unwelcome occurrences associated with drug use. Some of these events are predictable or preventable, whereas others are idiosyncratic. The off-label use of drugs in pediatric patients further complicates the assessment of adverse events because pediatric dosing based on recommended adult doses may not be appropriate. Adverse events often occur in pediatric patients in an environment of incomplete information about the drugs pharmacokinetics in the pediatric population, and the inherent metabolic differences between adults and children may not be detected with extrapolating maneuvers. Adverse event information may be acquired during the drug development process, including the preclinical, preapproval, and postapproval processes. However, the lack of clinical trials in pediatric patients indicates that such information is not available. Objective: This paper reviews the pharmacologic basis for the different types of adverse events in children and adults and provides examples of the differences between these 2 groups. Methods: Data from spontaneous reports of adverse events that support a trend may assist with initiating and identifying an early signal for an adverse event and an assessment of its occurrence. We summarized our experience with the exclusivity initiative aimed at improving the acquisition of knowledge about use of drugs in children. We also summarized the data available from some spontaneous adverse event reports as well as examined pertinent literature to provide state-of-knowledge information on the specific adverse events. Results: Of the first 16 products that were subsequently studied in children, 6 (37.5%) had significant changes in labeling that had an impact on safety or efficacy. Specifically, we were able to identify situations in which proposed dosing could have led to overdosing or underdosing. We also identified situations in which adverse events, previously undescribed, could be expected. Conclusions: This information provides a better understanding of potential reasons for adverse events and defines unique pediatric adverse events. The exclusivity initiative supports the need for formal studies in the pediatric population if the therapy is to be used in children.

Considerations for a Pediatric Biopharmaceutics Classification System (BCS): application to five drugs.

It has been advocated that biopharmaceutic risk assessment should be conducted early in pediatric product development and synchronized with the adult product development program. However, we are unaware of efforts to classify drugs into a Biopharmaceutics Classification System (BCS) framework for pediatric patients. The objective was to classify five drugs into a potential BCS. These five drugs were selected since both oral and intravenous pharmacokinetic data were available for each drug, and covered the four BCS classes in adults. Literature searches for each drug were conducted using Medline and applied to classify drugs with respect to solubility and permeability in pediatric subpopulations. Four pediatric subpopulations were considered: neonates, infants, children, and adolescents. Regarding solubility, dose numbers were calculated using a volume for each subpopulation based on body surface area (BSA) relative to 250xa0ml for a 1.73xa0m2 adult. Dose numbers spanned a range of values, depending upon the pediatric dose formula and subpopulation. Regarding permeability, pharmacokinetic literature data required assumptions and decisions about data collection. Using a devised pediatric BCS framework, there was agreement in adult and pediatric BCS class for two drugs, azithromycin (class 3) and ciprofloxacin (class 4). There was discordance for the three drugs that have high adult permeability since all pediatric permeabilities were low: dolasetron (class 3 in pediatric), ketoprofen (class 4 in pediatric), and voriconazole (class 4 in pediatric). A main contribution of this work is the identification of critical factors required for a pediatric BCS.

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 55u2009819 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 147u2009692 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.