Power calculations and placebo effect for future clinical trials in progressive supranuclear palsy.

ABSTRACT: BACKGROUND:Two recent randomized, placebo-controlled trials of putative disease-modifying agents (davunetide, tideglusib) in progressive supranuclear palsy (PSP) failed to show efficacy, but generated data relevant for future trials. METHODS:We provide sample size calculations based on data collected in 187 PSP patients assigned to placebo in these trials. A placebo effect was calculated. RESULTS:The total PSP-Rating Scale required the least number of patients per group (N?=?51) to detect a 50% change in the 1-year progression and 39 when including patients with ? 5 years disease duration. The Schwab and England Activities of Daily Living required 70 patients per group and was highly correlated with the PSP-Rating Scale. A placebo effect was not detected in these scales. CONCLUSIONS:We propose the 1-year PSP-Rating Scale score change as the single primary readout in clinical neuroprotective or disease-modifying trials. The Schwab and England Activities of Daily Living could be used as a secondary outcome. © 2016 International Parkinson and Movement Disorder Society.

SUBMITTER: Stamelou M 

PROVIDER: S-EPMC5289149 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature