Post-approval trials of new medicines: widening use or deepening knowledge? Analysis of 10 years of etanercept

Timing and Characteristics of Cumulative Evidence Available on Novel Therapeutic Agents Receiving Food and Drug Administration Accelerated Approval

Policy Points: Randomized trials-the gold standard of evaluating effectiveness-constitute a small minority of existing evidence on agents given accelerated approval. One-third of randomized trials are in therapeutic areas outside of FDA approval and less than half evaluate the therapeutic benefits of these agents but use them instead as common backbone treatments. Agents receiving accelerated approval are often tested concurrently in several therapeutic areas. For most agents, no substantial time lag is apparent between the average start dates of randomized trials evaluating their effectiveness and those using them as part of background therapies. There appears to be a tendency for therapeutic agents receiving accelerated approval to quickly become an integral component of standard treatment, despite potential shortcomings in their evidence base.

CONTEXT

Therapeutic agents treating serious conditions are eligible for Food and Drug Administration (FDA) accelerated approval. The clinical evidence accrued on agents receiving accelerated approval has not been systematically evaluated. Our objective was to assess the timing and characteristics of available studies.

METHODS

We first identified clinical studies of novel therapeutic agents receiving accelerated approval. We then (1) categorized those studies as randomized or nonrandomized, (2) explored whether they evaluated the FDA-approved indications, and (3) documented the available treatment comparisons. We also meta-analyzed the difference in start times between randomized studies that (1) did or did not evaluate approved indications and (2) were or were not designed to evaluate the agent's effectiveness.

FINDINGS

In total, 37 novel therapeutic agents received accelerated approval between 2000 and 2013. Our search of ClinicalTrials.gov identified 7,757 studies, which included 1,258,315 participants. Only one-third of identified studies were randomized controlled trials. Of 1,631 randomized trials with advanced recruitment status, 906 were conducted in therapeutic areas for which agents received initial accelerated approval, 202 were in supplemental indications, and 523 were outside approved indications. Only 411 out of 906 (45.4%) trials were designed to test the effectiveness of agents that received accelerated approval ("evaluation" trials); others used these agents as common background treatment in both arms ("background" trials). There was no detectable lag between average start times of trials conducted within and outside initially approved indications. Evaluation trials started on average 1.52 years (95% CI: 0.87 to 2.17) earlier than background trials.

CONCLUSIONS

Cumulative evidence on agents with accelerated approvals has major limitations. Most clinical studies including these agents are small and nonrandomized, and about a third are conducted in unapproved areas, typically concurrently with those conducted in approved areas. Most randomized trials including these therapeutic agents are not designed to directly evaluate their clinical benefits but to incorporate them as standard treatment.

Clinical Evidence Supporting US Food and Drug Administration Approval of Otolaryngologic Prescription Drug Indications, 2005-2014

Objective The US Food and Drug Administration (FDA) approves indications for prescription drugs based on premarket pivotal clinical studies designed to demonstrate safety and efficacy. We characterized the pivotal studies supporting FDA approval of otolaryngologic prescription drug indications. Study Design Retrospective cross-sectional analysis. Setting Publicly available FDA documents. Subjects Recently approved (2005-2014) prescription drug indications for conditions treated by otolaryngologists or their multidisciplinary teams. Drugs could be authorized for treatment of otolaryngologic disease upon initial approval (original indications) or thereafter via supplemental applications (supplemental indications). Methods Pivotal studies were categorized by enrollment, randomization, blinding, comparator type, and primary endpoint. Results Between 2005 and 2014, the FDA approved 48 otolaryngologic prescription drug indications based on 64 pivotal studies, including 21 original indications (19 drugs, 31 studies) and 27 supplemental indications (18 drugs, 33 studies). Median enrollment was 299 patients (interquartile range, 198-613) for original indications and 197 patients (interquartile range, 64-442) for supplemental indications. Most indications were supported by ≥1 randomized study (original: 20/21 [95%], supplemental: 21/27 [78%]) and ≥1 double-blinded study (original: 14/21 [67%], supplemental: 17/27 [63%]). About half of original indications (9/21 [43%]) and one-quarter of supplemental indications (7/27 [26%]) were supported by ≥1 active-controlled study. Nearly half (original: 8/21 [38%], supplemental: 14/27 [52%]) of all indications were approved based exclusively on studies using surrogate markers as primary endpoints. Conclusion The quality of clinical evidence supporting FDA approval of otolaryngologic prescription drug indications varied widely. Otolaryngologists should consider limitations in premarket evidence when helping patients make informed treatment decisions about newly approved drugs.

Association of NLRP3 and CARD8 genetic polymorphisms with juvenile idiopathic arthritis in a Taiwanese population

OBJECTIVES

An elevated interleukin (IL)-1β response in peripheral blood mononuclear cells (PBMCs) has been observed in systemic juvenile idiopathic arthritis (sJIA), suggesting a role for inflammasomes in the pathogenesis of JIA. We aimed to determine whether genetic polymorphisms of the NLRP3 inflammasome components confer risk for oligoarticular and polyarticular JIA in a Taiwanese population.

METHOD

A total of 118 JIA patients and 103 healthy controls were genotyped for rs4353135 OR2B11/NLRP3 and rs2043211 CARD8 polymorphisms. Clinical laboratory data and serum IL-1β of JIA patients were evaluated by medical chart review and enzyme-linked immunosorbent assay (ELISA), respectively. The production of IL-17 in lymphocytes of different genotype carriers was measured using flow cytometry.

RESULTS

The variant rs4353135 G allele carrier conferred increased risk for oligoarticular and polyarticular JIA. The G allele was also found to be associated with higher levels of clinical inflammatory markers. Moreover, G variant carriers enhanced the lymphocyte IL-17 response. The G/G genotype further increased the need for treatment with the tumour necrosis factor (TNF) inhibitor etanercept.

CONCLUSIONS

Our data indicate that the rs4353135 OR2B11/NLRP3 polymorphism might be functional in, and could contribute to, the pathophysiology of oligoarticular and polyarticular JIA in a Taiwanese population.