Related Experiment Video
Updated: Jul 14, 2026

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
Published on: May 25, 2020
Predictive value of the efficacy of glaucoma medications in regulatory trials: Phase I-III to post-marketing studies
1PRN Pharmaceutical Research Network, LLC, Dallas, TX, USA. info@prnorb.com
Purpose:
To determine the predictive value of early Phase trials (I-II) for the ocular hypotensive efficacy observed in Phases III and IV.
Design:
A review of published literature.
Methods:
This study evaluated 12 medicines in 65 articles in the literature with at least two phases available.
Results:
For medicines with Phase I results available (n=3), the average reduction in intraocular pressure (IOP) from untreated baseline was 16%, 26% for Phase II, 26% for Phase III, and 24% for Phase IV. For medicines with Phase II results available (n=6), the average reduction in IOP was 23%, 24% for Phase III, and 23% for Phase IV. For medicines with Phase III results available (n=11), the average reduction in IOP was 25% and 24% for Phase IV.
Conclusion:
This study indicates that early phase trials usually approximated the results of later regulatory studies and post-commercialization trials.
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