Gwaza L, Gordon J, Welink J, Potthast H, Leufkens H, Stahl M, García-Arieta A. Adjusted Indirect Treatment Comparison of the Bioavailability of WHO-Prequalified First-Line Generic Antituberculosis Medicines. Clin Pharmacol Ther. 2014 Nov; 96(5): 580-8
Background: Guidance and exploratory evidence indicate that the type of endpoints and the magnitude of their outcome can define a therapy’s clinical activity; however, little empirical evidence relates specific endpoint properties with regulatory outcomes.
Methods: We explored the relationship of 3 endpoint properties to regulatory outcomes by assessing 50 oncology marketing authorization applications (MAAs; reviewed from 2009 to 2013).
Results: Overall, 16 (32%) had a negative outcome. The most commonly used hard endpoints were overall survival (OS) and the duration of response or stable disease. OS was a component of 91% approved and 63% failed MAAs. The most commonly used surrogate endpoints were progression-free survival (PFS), response rate, and health-related quality of life assessments. There was no difference (p = .3801) between the approved and failed MAA cohorts in the proportion of hard endpoints used. A mean of slightly more than four surrogate endpoints were used per approved MAA compared with slightly more than two for failed MAAs. Longer OS and PFS duration outcomes were generally associated with approvals, often when not statistically significant. The approved cohort was associated with a preponderance of statistically significant (p < .05) improvements in primary endpoints (p < .0001 difference between the approved and failed groups).
Conclusion: Three key endpoint properties (type of endpoint [hard/surrogate], magnitude of an endpoint outcome, and its statistical significance) are consistent with the European Medicines Agency guidance and, notwithstanding the contribution of unique disease-specific circumstances, are associated with a predictable positive outcome for oncology MAAs.