Evaluation of the fragility of pivotal trials used to support US Food and Drug Administration approval for plaque psoriasis

Abstract

Background: Over the last 5 years, there has been a rapid growth in the number of clinical trials used to support a US Food and Drug Administration (FDA) approval for systemic therapies with labeled indications for plaque psoriasis.

Objective: We aim to evaluate the fragility of clinical trial data used to support FDA approval of therapies for psoriasis.

Methods: We reviewed the primary endpoints of the pivotal trials of all systemic medications with a labeled indication for plaque psoriasis available from Drugs@FDA.

Results: Sixty-nine clinical trial primary endpoints met inclusion criteria and were assessed for robustness, yielding a median fragility index of 72 and a median fragility quotient of 0.19.

Limitations: Efficacy and statistical analysis data for several approved medications were not available on the product label or on Drugs@FDA.

Conclusions: When compared with randomized controlled trials for FDA approval across various diseases, pivotal trials in psoriasis appear quite robust to changes in outcomes.

Keywords: Physician Global Assessment; Psoriasis Area and Severity Index; biologics; fragility index; fragility quotient; pivotal trials; psoriasis.