Effect of renal function on antihypertensive drug safety and efficacy in children.

BACKGROUND: Hypertension and chronic kidney disease (CKD) are common comorbidities. Guidelines recommend treating hypertension in children with CKD because it is a modifiable risk factor for subsequent cardiovascular disease. Children with CKD are frequently excluded from antihypertensive drug trials. Consequently, safety and efficacy data for antihypertensive drugs are lacking in children with CKD. METHODS: We determined the incidence of adverse events in 10 pediatric antihypertensive trials to determine the effect of renal function on antihypertensive safety and efficacy in children. These trials were submitted to the US Food and Drug Administration from 1998 to 2005. We determined the number and type of adverse events reported during the trials and compared these numbers in participants with normal renal function and those with decreased function (defined as an estimated glomerular filtration rate [eGFR] <90 mL/min/1.73 m2 calculated using the original Schwartz equation). RESULTS: Among the 1,703 children in the 10 studies, 315 had decreased renal function. We observed no difference between the two cohorts in the incidence of adverse events or adverse drug reactions related to study drug. Only 5 participants, all with decreased renal function, experienced a serious adverse event; none was recorded by investigators to be study drug-related. Among treated participants, children with decreased renal function who received a high dose of study drug had a significantly larger drop in diastolic blood pressure compared with children with normal renal function. CONCLUSIONS: These data show that antihypertensive treatment in children with renal dysfunction can be safe and efficacious, and consideration should be given to their inclusion in selected drug development programs.

Pediatric registries at the Food and Drug Administration: design aspects that increase their likelihood of success.

PURPOSE: To determine aspects of the design of pediatric registries that contribute to the success of registries conducted as a postmarketing study following approval of drugs or biological products by the US Food and Drug Administration. METHODS: Pediatric registries for drugs and biological products were identified by searching the US Food and Drug Administration Postmarketing Requirements and Commitments database. Based on the recruitment of patients, the meeting of predetermined deadlines, and the submission of data, we classified studies as successful, unsuccessful, or unevaluable. Design aspects of successful and unsuccessful registries were examined for commonalities. RESULTS: Thirty-eight studies were identified, and ten registries met the criteria for successful. Four (40%) successful registries utilized a registry established prior to product approval, and six (60%) were disease-based. Among unsuccessful registries, none were disease-based or utilized a pre-existing registry. CONCLUSIONS: Characteristics identified as more common to successful registries included utilizing a disease-based registry and a registry established prior to product approval. Future studies might examine a larger sample of registries to see if these aspects consistently result in successful studies. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The impact of the written request process on drug development in childhood cancer.

PURPOSE: The Food and Drug Administration (FDA) Modernization Act, enacted in 1997, created a pediatric exclusivity incentive allowing sponsors to qualify for an additional 6 months of marketing exclusivity after satisfying the requirements outlined in the Written Request (WR). This review evaluates the impact of the WR mechanism on the development of oncology drugs in children. METHODS: A search of the FDA document archiving, reporting, and regulatory tracking system was performed for January 1, 2000 to December 31, 2010. Drugs were identified and pediatric-specific labeling information was obtained from Drugs@fda.gov and FDA Pediatric Labeling Changes Table. RESULTS: Fifty WRs have been issued for oncology drugs. Pediatric studies have been submitted for 14 drugs. Thirteen received pediatric exclusivity. As of December 31, 2010, labeling changes have been made for 11 drugs. Three drugs were approved for pediatric use. CONCLUSION: WRs have provided a mechanism to promote the study of drugs in pediatric malignancies. Information from studies resulting from the WRs regarding safety, pharmacokinetics, and tolerability of oncology drugs has been incorporated into pediatric labeling for 11/14 of the drugs. Earlier communication and collaboration between the FDA, National Cancer Institute, clinical investigators, and commercial sponsors are envisioned to facilitate the identification and prioritization of emerging new drugs of interest for WR consideration. Since this is the only regulatory mechanism, resulting from specific legislative initiatives relevant to cancer drug development for children, efforts to enhance its impact on increasing drug approval for pediatric cancer indications are warranted.

Duration of Pediatric Clinical Trials Submitted to the US Food and Drug Administration.

Importance: The increasing prevalence of pediatric chronic disease has resulted in increased exposure to long-term drug therapy in children. The duration of recently completed drug trials that support approval for drug therapy in children with chronic diseases has not been systematically evaluated. Such information is a vital first step in forming safety pharmacovigilance strategies for drugs used for long-term therapy in children. Objective: To characterize the duration of clinical trials submitted to the US Food and Drug Administration (FDA) for pediatric drug approvals, with a focus on drugs used for long-term therapy. Design and Setting: A review was performed of all safety and efficacy clinical trials conducted under the Best Pharmaceuticals for Children Act or the Pediatric Research Equity Act and submitted to the FDA from September 1, 2007, to December 31, 2014, to support the approval of drugs frequently used for long-term therapy in children. Statistical analysis was performed from July 1, 2015, to December 31, 2017. Main Outcomes and Measures: Maximum duration of trials submitted to support FDA approval of drugs for children. Results: A total of 306 trials supporting 86 drugs intended for long-term use in children were eligible for the primary analysis. The drugs most commonly evaluated were for treatment of neurologic (25 [29%]), pulmonary (16 [19%]), and anti-infective (14 [16%]) indications. The median maximum trial duration by drug was 44 weeks (minimum, 1.1 week; maximum, 364 weeks). For nearly two-thirds of the drugs (52 [61%]), the maximum trial duration was less than 52 weeks. For 10 of the drugs (12%), the maximum trial duration was 3 years or more. Maximum duration of trials did not vary by therapeutic category, minimum age of enrollment, calendar year, or legislative mandate. Conclusions and Relevance: Pediatric clinical trials designed to sufficiently investigate drug safety and efficacy to support FDA approval are of relatively limited duration. Given the potential long-term exposure of patients to these drugs, the clinical community should consider whether new approaches are needed to better understand the safety associated with long-term use of these drugs.

Serious Adverse Events Associated with Off-Label Use of Azithromycin or Fentanyl in Children in Intensive Care Units: A Retrospective Chart Review.

OBJECTIVES: Half of prescription drugs commonly given to children lack product labeling on pediatric safety, efficacy, and dosing. Two drugs most widely used off-label in pediatrics are azithromycin and fentanyl. We sought to determine the risk of serious adverse events (SAEs) when oral azithromycin or intravenous/intramuscular fentanyl are used off-label compared to on-label in pediatric intensive care units (ICUs). STUDY DESIGN: Six pediatric hospitals participated in a retrospective chart review of patients administered oral azithromycin (n = 241) or intravenous/intramuscular fentanyl (n = 367) between January 5, 2013 and December 26, 2014. Outcomes were SAEs by drug and labeling status: off-label compared to on-label by Food and Drug Administration (FDA)-approved age and/or indication. Statistical analysis was performed using logistic regression to estimate odds ratios (ORs) and Cox regression to estimate hazard ratios (HRs). RESULTS: Twenty-one (9%) children receiving azithromycin experienced SAEs. Off-label use of azithromycin was not associated with a higher risk of SAE (OR 0.87, 95% CI 0.27-2.71, p = 0.81). Ninety-five (26%) children receiving fentanyl experienced SAEs. Fentanyl off-label use by both age and indication was not associated with a higher risk of overall SAEs compared to on-label use (OR 1.99, 95% CI 0.94-4.19, p = 0.07). However, the risk of the SAE respiratory depression was significantly greater when fentanyl was used off-label by both age and indication (OR 5.05, 95% CI 1.08-23.56, p = 0.044). Results based on HRs were similar. CONCLUSIONS: Azithromycin off-label use in pediatric ICUs does not appear to be associated with an increased risk of SAEs. Off-label use of fentanyl appears to be more frequently associated with respiratory depression when used off-label by both age and indication in pediatric ICUs. Prospective studies should be undertaken to assess the safety and efficacy of fentanyl in the pediatric population so that data can be added to the FDA labeling.

Neonatal Safety Information Reported to the FDA During Drug Development Studies.

BACKGROUND: Relatively few neonatal drug development studies have been conducted, but an increase is expected with the enactment of the Food and Drug Administration Safety and Innovation Act (FDASIA). Understanding the safety of drugs studied in neonates is complicated by the unique nature of the population and the level of illness. The objective of this study was to examine neonatal safety data submitted to the FDA in studies pursuant to the Best Pharmaceuticals for Children Act (BPCA) and the Pediatric Research Equity Act (PREA) between 1998 and 2015. METHODS: FDA databases were searched for BPCA and/or PREA studies that enrolled neonates. Studies that enrolled a minimum of 3 neonates were analyzed for the presence and content of neonatal safety data. RESULTS: The analysis identified 40 drugs that were studied in 3 or more neonates. Of the 40 drugs, 36 drugs received a pediatric labeling change as a result of studies between 1998 and 2015, that included information from studies including neonates. Fourteen drugs were approved for use in neonates. Clinical trials for 20 of the drugs reported serious adverse events (SAEs) in neonates. The SAEs primarily involved cardiovascular events such as bradycardia and/or hypotension or laboratory abnormalities such as anemia, neutropenia, and electrolyte disturbances. Deaths were reported during studies of 9 drugs. CONCLUSIONS: Our analysis revealed that SAEs were reported in studies involving 20 of the 40 drugs evaluated in neonates, with deaths identified in 9 of those studies. Patients enrolled in studies were often critically ill, which complicated determination of whether an adverse event was drug-related. We conclude that the traditional means for collecting safety information in drug development trials needs to be adjusted for neonates and will require the collaboration of regulators, industry, and the clinical and research communities to establish appropriate definitions and reporting strategies for the neonatal population.

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.

Predicting neonatal pharmacokinetics from prior data using population pharmacokinetic modeling.

Selection of the first dose for neonates in clinical trials is very challenging. The objective of this analysis was to assess if a population pharmacokinetic (PK) model developed with data from infants to adults is predictive of neonatal clearance and to evaluate what age range of prior PK data is needed for informative modeling to predict neonate exposure. Two sources of pharmacokinetic data from 8 drugs were used to develop population models: (1) data from all patients > 2 years of age, and (2) data from all nonneonatal patients aged > 28 days. The prediction error based on the models using data from subjects > 2 years of age showed bias toward overprediction, with median average fold error (AFE) for CL predicted/CLobserved greater than 1.5. The bias for predicting neonatal PK was improved when using all prior PK data including infants as opposed to an assessment without infant PK data, with the median AFE 0.91. As an increased number of pediatric trials are conducted in neonates under the Food and Drug Administration Safety and Innovation Act, dose selection should be based on the best estimates of neonatal pharmacokinetics and pharmacodynamics prior to conducting efficacy and safety studies in neonates.

Drug labeling and exposure in neonates.

IMPORTANCE: Federal 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. OBJECTIVE: To quantify progress made in neonatal studies and neonatal information in product labeling as a result of recent legislation. DESIGN, SETTING, AND PARTICIPANTS: We 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. EXPOSURE: Infants exposed to a drug studied in neonates as identified by the FDA website. MAIN OUTCOMES AND MEASURES: Number of drug studies with neonates and rate of exposure per 1000 admissions among infants admitted to an NICU. RESULTS: In 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). CONCLUSIONS AND RELEVANCE: Few 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.

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.

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.

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.