Phase II is an exciting
and challenging phase where efficacy is initially tested for a new
drug. This may include efficacy assessments for a single dose or
multiple doses, possibly in separate studies (traditional phase IIa
and IIb studies) or in a single study, such as a seamless phase IIa
or IIb study.
When testing multiple doses, one of the key strategic decisions is how wide of a dosing range will be tested and what doses should be tested across that interval. Though many dose-ranging studies are powered for pairwise comparisons, the strength of dose-response modeling is in the ability to better understand the drug effect across the dosing interval. A wide dose range or higher dosing ratio helps adequately ...