Use of larger versus smaller drug-safety databases before regulatory approval: the trade-offs

The Impact of Variability in Patient Exposure During Premarket Clinical Development on Postmarket Safety Outcomes

We characterized the size of the premarket safety population for 278 small-molecule new molecular entities (NMEs) and 61 new therapeutic biologics (NTBs) approved by the US Food and Drug Administration (FDA) between October 1, 2002, and December 31, 2014, evaluating the relationship of premarket safety population size to regulatory characteristics and postmarket safety outcomes. The median size of the safety population was 1,044, and was lower for NTBs than NMEs (median: 920 vs. 1,138, P = 0.04), orphan products than nonorphan products (393 vs. 1,606, P < 0.001), and for products with fast-track designation (617 vs. 1,455, P < 0.001), priority review (630 vs. 1,735, P < 0.001), and accelerated approval (475 vs. 1,164, P < 0.001), than products without that designation. The median number of postmarket safety label updates and issues added to the label were higher with larger premarket exposure among nonorphan products, but not among orphan products. Products with accelerated approval using a surrogate end point had a higher median number of safety issues added to the label than those with full approval, but this did not vary with the size of the safety population; fast-track and priority review were not associated with the number of safety issues added to the label. A smaller safety population size was associated with a longer time to first safety outcome for nonorphan products but not orphan products. For orphan and nonorphan products combined, smaller premarket safety population size is not associated with the number or timing of postmarket safety outcomes, regardless of expedited program participation.

Evaluation of Pre-marketing Factors to Predict Post-marketing Boxed Warnings and Safety Withdrawals

INTRODUCTION

An important goal in drug regulation is understanding serious safety issues with new drugs as soon as possible. Achieving this goal requires us to understand whether information provided during the Food and Drug Administration (FDA) drug review can predict serious safety issues that are usually identified after the product is approved. However, research on this topic remains understudied. In this paper, we examine whether any pre-marketing drug characteristics are associated with serious post-marketing safety actions.

METHODS

We study this question using an internal FDA database containing every new small molecule drug submitted to the FDA's Center for Drug Evaluation and Research (CDER) on or after November 21, 1997, and approved and commercially launched before December 31, 2009. Serious post-marketing safety actions include whether these drugs ever experienced either a post-marketing boxed warning or a withdrawal from the market due to safety concerns. A random effects logistic regression model was used to test whether any pre-marketing characteristics were associated with either post-marketing safety action.

RESULTS

A total of 219 new molecular entities were analyzed. Among these drugs, 11 experienced a safety withdrawal and 30 received boxed warnings by July 31, 2016. Contrary to prevailing hypotheses, we find that neither clinical trial sample sizes nor review time windows are associated with the addition of a post-marketing boxed warning or safety withdrawal. However, we do find that new drugs approved with either a boxed warning or priority review are more likely to experience post-marketing boxed warnings. Furthermore, drugs approved with boxed warnings tend to receive post-marketing boxed warnings resulting from new safety information that are unrelated to the original warning. Drugs approved with a boxed warning are 3.88 times more likely to receive a post-marketing boxed warning, while drugs approved with a priority review are 3.51 times more likely to receive a post-marketing boxed warning.

CONCLUSION

Although drugs approved with a boxed warning or priority review are more likely to experience serious post-marketing safety events, other information provided during the FDA drug review that is easy to quantify is generally not associated with post-marketing safety events. It appears that these post-marketing events are not discernible during a pre-marketing review and therefore might not be avoidable using current review data.

Estimating the incremental net health benefit of requirements for cardiovascular risk evaluation for diabetes therapies

PURPOSE

To evaluate the advantages and disadvantages of pre-approval requirements for safety data to detect cardiovascular (CV) risk contained in the December 2008 U.S. Food and Drug Administration (FDA) guidance for developing type 2 diabetes drugs compared with the February 2008 FDA draft guidance from the perspective of diabetes population health.

METHODS

We applied the incremental net health benefit (INHB) framework to quantify the benefits and risks of investigational diabetes drugs using a common survival metric (life-years [LYs]). We constructed a decision analytic model for clinical program development consistent with the requirements of each guidance and simulated diabetes drugs, some of which had elevated CV risk. Assuming constant research budgets, we estimate the impact of increased trial size on drugs investigated. We aggregate treatment benefit and CV risks for each approved drug over a 35-year horizon under each guidance.

RESULTS

The quantitative analysis suggests that the December 2008 guidance adversely impacts diabetes population health. INHB was -1.80 million LYs, attributable to delayed access to diabetes therapies (-0 .18 million LYs) and fewer drugs (-1.64 million LYs), but partially offset by reduced CV risk exposure (0.02 million LYs). Results were robust in sensitivity analyses.

CONCLUSION

The health outcomes impact of all potential benefits and risks should be evaluated in a common survival measure, including health gain from avoided adverse events, lost health benefits from delayed or for gone efficacious products, and impact of alternative policy approaches. Quantitative analysis of the December 2008 FDA guidance for diabetes therapies indicates that negative impact on patient health will result.

The cost-effectiveness of periodic safety update reports for biologicals in Europe

We analyzed the cost-effectiveness of all Periodic Safety Update Reports (PSURs) submitted for biologicals in Europe from 1995 to 2009 by comparing two regulatory scenarios: full regulation (PSUR reporting) and limited regulation (no PSUR reporting, but all other parts of the pharmacovigilance framework remain in place). During this period, PSUR reporting resulted in the detection of 2 out of a total of 24 urgent safety issues for biologicals: (i) distant spread of botulinum toxin and (ii) edema/fluid collection associated with off-label use of dibotermin-alfa. We used Markov-chain life tables to calculate costs and health effects of PSURs. The incremental cost-effectiveness ratio (ICER) of full regulation (PSUR reporting) vs. limited regulation (no PSUR reporting) for the base-case scenario was \[euro]342,110 per quality-adjusted life year (QALY) gained. It is possible to assess the cost-effectiveness of regulatory requirements using the same methods as those used in assessing the cost-effectiveness of medical interventions.

End points for comparative effectiveness research in heart failure

CER for heart failure continues to evolve, including its assessment of end points. Reliance on surrogate end points is unacceptable as a means of definitively establishing comparisons of clinical effectiveness. CER needs to focus on measures that clearly reflect clinical effectiveness and safety, not just survival but also standardized assessments of health status and detailed resource utilization, and it must do so in a standardized way to allow for comparison. This strategy almost certainly requires increased reliance on prospective studies with proactive end-point capture, preferably in the setting of randomized allocation of the interventions being compared.

End points for clinical trials in acute heart failure syndromes

Acute heart failure syndromes (AHFS) remain a major cause of morbidity and mortality, in part because the development of new therapies for these disorders has been marked by frequent failure and little success. The heterogeneity of current approaches to AHFS drug development, particularly with regard to end points, remains a major potential barrier to progress in the field. End points involving hemodynamic status, biomarkers, symptoms, hospital stay, end organ function, and mortality have all been employed either alone or in combination in recent randomized clinical trials in AHFS. In this review, we will discuss the various end point domains from both a clinical and a statistical perspective, summarize the wide variety of end points used in completed and ongoing AHFS studies, and suggest steps for greater standardization of end points across AHFS trials.

Is having more preapproval data the best way to assure drug safety?

An intensified focus on drug safety often leads to demands for more data collection prior to drug approval. Other approaches can be used, such as enhanced postmarketing surveillance. Many drug benefits and adverse effects are unlikely to become apparent before wide distribution among diverse patients. The best balance of pre- and postapproval data collection may vary by drug. The consequences of alternative strategies are complex and not always immediately apparent, so formal modeling offers the best approach to determine which strategy is optimal in each case.