definiens: shall mean a human clinical trial conducted on patients with the disease being studied for theprincipal purpose of achieving a preliminary determination of efficacy and selection of the dose regimen(s ) to be studied in aPhase III Trial of a Product, as further described in 21 C.F.R. § 312.21(b ), and, if the defined end - points are met, is sufficient toallow the conduct of such a Phase III Trial ( including any such equivalent clinical study in any country other than the UnitedStates ), all in accordance with the trial protocol . For clarity : ( a ) to be a Phase II Trial, the protocol must include at least oneprimary end - point pertaining to efficacy ; and ( b ) if a trial is planned as a two - stage trial, in which the first stage is a Phase ITrial, and if the defined safety endpoints are met as described in the protocol for such trial, the trial proceeds to a second stagethat meets the criteria above for a Phase II Trial, then only such second, Phase II stage of such trial shall be deemed a Phase IITrial