Power calculations and placebo effect for future clinical trials in progressive supranuclear palsy. Issue 5 (7th March 2016)

• Record Type: Journal Article
• Authors: Stamelou, Maria; Schöpe, Jakob; Wagenpfeil, Stefan; Del Ser, Teodoro; Bang, Jee; Lobach, Iryna Y.; Luong, Phi; Respondek, Gesine; Oertel, Wolfgang H.; Boxer, AdamL.; Höglinger, Günter U.
• Is Part Of: Movement disorders. Volume 31:Issue 5(2016)
• Page Start: 742
• Page End: 747
• Publication Date: 2016-03-07
• Subjects: progressive supranuclear palsy -- power calculation -- placebo effect -- clinical trials -- rate of progression; Movement disorders -- Periodicals; 610
• DOI: 10.1002/mds.26580
• Languages: English
• ISSNs: 0885-3185

Abstract

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