Regulatory-grade clinical trial design using real-world data.

Real-world data and evidence provide the potential to address the effectiveness and safety of drugs. The U.S. Food & Drug Administration has initiated a program to evaluate the potential use of real-world evidence for regulatory uses. Whether a study is designed for regulatory purposes or for other purposes, existing regulation and guidance provide a reference for high-quality studies. Clarifying the study objectives and the role of real-world data in the study are important considerations. Robustness and transparency of the analysis allow for greater understanding and acceptance of the study results.

The impact of FDA regulatory activities on incident dispensing of LABA-containing medication: 2005-2011.

OBJECTIVE: Evidence of safety issues associated with long-acting beta2-agonist (LABA) treatment has led to multiple regulatory activities by the U.S. Food and Drug Administration (FDA) on this class of medications. This study describes the impact of the regulatory activities on incident LABA-containing medication dispensing. METHODS: A monthly rolling cohort of asthma patients who were eligible to initiate a LABA-containing product was created in the Mini-Sentinel Distributed Database between January 2005 and June 2011. Cohorts of individuals who initiated LABA were examined for the changes in the proportions of single-ingredient to fixed-dose inhaled corticosteroid (ICS)-LABA initiators, appropriate initiation of LABA-containing products, and use of controller medications. The impact of the 2005 and 2010 FDA regulatory activities associated with LABA-containing products was measured using interrupted time series with segmented regression. RESULTS: LABA-containing product initiation was declining prior to the 2005 regulatory activities and continued to decline over the study period, accompanied by increased initiation of fixed dose ICS-LABA among LABA initiators. While the 2010 regulatory activities had no immediate impact on the proportion of LABA initiation in patients with prior controller medication dispensing and/or poor asthma control, there was an increasing positive trend toward LABA initiation in the appropriate patient population after the regulatory activities. CONCLUSION: The 2005 and 2010 FDA regulatory activities likely had an impact on communicating the safety concerns of LABA products. However, the impact cannot be viewed independent of scientific publications, guidelines for asthma treatment and other regulatory activities.

Important statistical considerations in the evaluation of post-market studies to assess whether opioids with abuse-deterrent properties result in reduced abuse in the community.

PURPOSE: Abuse, misuse, addiction, overdose, and death associated with non-medical use of prescription opioids have become a serious public health concern. Reformulation of these products with abuse-deterrent properties is one approach for addressing this problem. FDA has approved several extended-release opioid analgesics with abuse-deterrent labeling, the bases of which come from pre-market studies. As all opioid analgesics must be capable of delivering the opioid in order to reduce pain, abuse-deterrent properties do not prevent abuse, nor do pre-market evaluations ensure that there will be reduced abuse in the community. Utilizing data from various surveillance systems, some recent post-market studies suggest a decline in abuse of extended-release oxycodone after reformulation with abuse-deterrent properties. We discuss challenges stemming from the use of such data. METHODS: We quantify the relationship between the sample, the population, and the underlying sampling mechanism and identify the necessary conditions if valid statements about the population are to be made. The presence of other interventions in the community necessitates the use of comparators. We discuss the principles under which the use of comparators can be meaningful. CONCLUSIONS: Results based on surveillance data need to be interpreted with caution as the underlying sampling mechanisms can bias the results in unpredictable ways. The use of comparators has the potential to disentangle the effect due to the abuse-deterrence properties from those due to other interventions. However, identifying a comparator that is meaningful can be very difficult.

Changing patterns of asthma medication use related to US Food and Drug Administration long-acting ß2-agonist regulation from 2005-2011.

BACKGROUND: Safety concerns associated with long-acting ß2-agonists (LABAs) have led to many US Food and Drug Administration (FDA) regulatory activities for this class of drugs. Little is known about the effect of these regulatory activities on use of LABA-containing agents or other asthma medications. METHODS: We created rolling cohorts of pediatric and adult asthmatic patients in the Mini-Sentinel Distributed Database between January 2005 and June 2011. The proportions of asthmatic patients using LABA-containing products, inhaled corticosteroids (ICSs), leukotriene modifiers, short-acting ß2-agonists, oral corticosteroids, other bronchodilators, and no medications were measured on a monthly basis, and the changes were evaluated by using interrupted time series with segmented regression analysis. RESULTS: When the 2005 regulatory activity was announced, there were statistically significant decreases in the use of fixed-dose ICS-LABA agents in children (-0.98 percentage points) and adults (-1.24 percentage points). Increased use of ICSs and leukotriene modifiers was observed just after the regulatory activities were announced in both children and adults. Although of smaller magnitude, continued favorable changes in the use of LABA agents were observed after the 2010 FDA regulatory activity. CONCLUSION: The 2005 and 2010 FDA regulatory activities might have contributed to reduced use of LABA agents, as intended; however, their effect, independent of other factors, cannot be determined. Use of other classes of asthma medications was similarly affected.

The role of quantitative safety evaluation in regulatory decision making of drugs.

Evaluation of safety is a critical component of drug review at the US Food and Drug Administration (FDA). Statisticians are playing an increasingly visible role in quantitative safety evaluation and regulatory decision-making. This article reviews the history and the recent events relating to quantitative drug safety evaluation at the FDA. The article then focuses on five active areas of quantitative drug safety evaluation and the role Division of Biometrics VII (DBVII) plays in these areas, namely meta-analysis for safety evaluation, large safety outcome trials, post-marketing requirements (PMRs), the Sentinel Initiative, and the evaluation of risk from extended/long-acting opioids. This article will focus chiefly on developments related to quantitative drug safety evaluation and not on the many additional developments in drug safety in general.

Risk of acute myocardial infarction, stroke, or death in patients initiating olmesartan or other angiotensin receptor blockers - a cohort study using the Clinical Practice Research Datalink.

PURPOSE: Results of two randomized trials (ROADMAP and ORIENT) suggest that high-dose (40 mg/day) olmesartan (Olm) is associated with increased cardiovascular mortality compared to placebo in diabetic patients. We evaluated the risks of acute myocardial infarction (AMI) and death in patients initiating Olm compared with an active comparator group, other angiotensin receptor blockers (ARBs), with a focus on high-dose and diabetic subgroups. METHODS: We conducted a cohort study with patients who initiated Olm or another ARB between 2003 and 2011, using the UK Clinical Practice Research Datalink GOLD. We included patients who had no prior ARB or angiotensin converting enzyme inhibitor exposure during the preceding 6 months. Hazard ratios (HRs) were estimated using Cox regression models with both multivariable adjustment and propensity score matching. RESULTS: There were 3964 Olm and 54 653 other-ARB initiators, respectively. Adjusted HRs comparing Olm and other-ARBs were 1.04 (95% CI: 0.75-1.42) for AMI and 1.16 (0.95-1.42) for death, using multivariable adjustment. Comparing patients initiated with a high-dose Olm and a high-dose other-ARB, HRs were 3.09 (0.94-10.13) for AMI and 2.03 (0.74-5.61) for death, using multivariable adjustment; and 4.38 (0.97-19.66) and 1.99 (0.63-6.32) for AMI and death, using propensity score matching. CONCLUSIONS: Overall, no differences in risk were observed in the main cohort analyses comparing Olm initiators with patients initiating therapy with other ARBs; however, HRs were marginally increased for all study endpoints which compared high-dose subgroups, suggesting potential increased risk may be associated with high-dose Olm. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Use of selective serotonin reuptake inhibitors in pregnancy and cardiac malformations: a propensity-score matched cohort in CPRD.

PURPOSE: Research on the association of maternal selective serotonin reuptake inhibitor (SSRI) use and cardiac malformations in the offspring has yielded conflicting findings. We therefore sought to further investigate the association using data from a large population-based cohort in the UK. METHODS: The study population consisted of 149 464 pregnancies ending in a live birth between January/1996 and November/2010 from the Clinical Practice Research Datalink's Mother Baby Link. We created propensity-score matched cohorts of first-trimester SSRI users who did not use other antidepressants in the same gestational period ('SSRI users', n=3046) and non-antidepressant users (no use from the 3 months before pregnancy through the second trimester of pregnancy, 'non-users'; n=8991). Weighted logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of cardiac malformations overall and septal defects diagnosed in the first year of life, or in the first 6 years of life. RESULTS: Sixteen infants with cardiac malformations were identified among SSRI users; 10 of them were septal defects. Among non-users, there were 48 infants with cardiac malformations, 26 of whom had septal defects. The OR (95% CI) for cardiac malformations was 1.00 (0.50; 2.00), and for septal defects was 1.15 (0.46; 2.87). Results were similar for cardiac malformations diagnosed in the first 6 years of life, and in several sensitivity analyses that were also implemented. CONCLUSIONS: The results of this study are most compatible with no association between maternal use of SSRIs in early pregnancy and cardiac malformations or septal defects in the offspring. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Regulatory issues of propensity score methodology application to drug and device safety studies.

While randomized, well-controlled, clinical trials have been viewed as the gold standard in the evaluation of medical products, including drugs, biological products, and medical devices, it is not uncommon for safety assessment to be performed using observational studies, for ethical or practical reasons. In observational studies, various biases could be introduced in every stage and aspect of study, and consequently the resulting statistical inference may carry a lower level of scientific assurance, compared to randomized trials. To ensure the objectivity of study design and interpretability of the results, it is critical to address the challenges of such studies. In this paper, we share regulatory considerations on the prospective design of observational studies to address safety issues using propensity score methodology.

Age and risks of FDA-approved long-acting ß2-adrenergic receptor agonists.

OBJECTIVE: To determine the risk, by age group, of serious asthma-related events with long-acting ß(2)-adrenergic receptor agonists marketed in the United States for asthma. METHODS: The US Food and Drug Administration performed a meta-analysis of controlled clinical trials comparing the risk of LABA use with no LABA use for patients 4 to 11, 12 to 17, 18 to 64, and older than 64 years old. The effects of age on a composite of asthma-related deaths, intubations, and hospitalizations (asthma composite index) and the effects of concomitant inhaled corticosteroid (ICS) use were analyzed. RESULTS: One hundred ten trials with 60 954 patients were included in the meta-analysis. The composite event incidence difference for all ages was 6.3 events per 1000 patient-years (95% confidence interval [CI]: 2.2-10.3) for using LABAs compared with not using LABAs. The largest incidence difference was observed for the 4- to 11-year age group (30.4 events per 1000 patient-years [95% CI: 5.7-55.1]). Differences according to age were statistically significant (P = .020). Results for the subgroup of patients with concomitant ICS use (n = 36 210) were similar to the overall results; with assigned ICSs (n = 15 192), the incidence difference was 0.4 events per 1000 patient-years (95% CI: -3.8 to 4.6), and there was no statistically significant difference according to age group. CONCLUSIONS: The excess of serious asthma-related events attributable to LABAs was greatest among children. Additional data are needed to assess risks of LABA use for children with simultaneous ICS use.

Performance Measures for Geometric Fitting in the NIST Algorithm Testing and Evaluation Program for Coordinate Measurement Systems.

The Algorithm Testing and Evaluation Program for Coordinate Measurement Systems (ATEP-CMS) is a Special Test Service offered under the NIST Calibration Program. ATEP-CMS evaluates the performance of geometric fitting software used in coordinate measurement systems. It is a Special Test because it is a new type of NIST service, experimental in nature and unsupported by historical data. This report documents and explains the rationale of the performance measures used in ATEP-CMS and analyzes the uncertainties of those measures.