PIANO™ requires clinically relevant sample sizes to assess reduction in observed atrophy as early as 6 months from baseline.
Sample Sizes for PIANO™ Regional Atrophy
Sample size calculations for the 6, 12, 18, and 24 month per arm estimates required to observe 20%-80% reductions in atrophy in a treated group compared to an untreated group. The sample size estimates are color-coded, where the green hues indicate less than 50 subjects per arm.
The tables show sample size calculations for an assessment of reduction in atrophy in a treated group compared to an untreaded group in each FTD variant over 6, 12, 18, and 24 months
The behavioral variants, which have a similar rate of atrophy to the nfvPPA variants (as illustrated on the previous slide), have more variability within the population assessed, leading to higher sample size estimates. Within 18 months from baseline, less than 50 subjects per arm are estimated to be required to observe a 40% slowing of the observed brain atrophy in the Thalamus.
In the nfvPPA population, by 18 months, less than 50 subjects per arm are required to observe a 40-80% slowing of atrophy in the Thalamus, Frontal Cortex, and Temporal Cortex regions, as well as expansion of the Lateral Ventricles.
In the svPPA population, as early as 6 months, fewer than 50 subjects per arm are required to observe an 40% slowing of atrophy in the Hippocampus and Temporal Cortex.