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Fig. 1 | Alzheimer's Research & Therapy

Fig. 1

From: A randomized, double-blind, phase 2b proof-of-concept clinical trial in early Alzheimer’s disease with lecanemab, an anti-Aβ protofibril antibody

Fig. 1

Lecanemab Study 201 study design. Study 201 (NCT01767311) was an 18-month, multicenter, double-blind, placebo-controlled Bayesian design clinical trial employing response adaptive randomization across placebo and five lecanemab arms (2.5 mg/kg biweekly, 5 mg/kg monthly, 5 mg/kg biweekly, 10 mg/kg monthly, 10 mg/kg biweekly) to assess safety and efficacy in subjects with early Alzheimer's disease. At the first three interim analyses, if there is a .5% posterior probability that the most likely ED90 is superior to placebo by the (clinically significant difference; 25%), the trial will stop early for futility. Beginning at the 350-subject IA, and continuing to completion of the trial, the futility criterion is increased to 7.5%. Interim monitoring for early success occurs at each IA beginning when 350 subjects have been enrolled. At this point, if enrollment were to stop for early success, enough subjects would be available to complete the trial so that the full dose response could be modeled. If there is a .95% posterior probability that the most likely ED90 is better than placebo by the CSD, then early success is declared. Enrollment is stopped, but all randomized subjects continue for the full 18-month duration of the study. If the trial is not stopped early for futility or success, then trial success is evaluated at the completion of the trial when both accrual and follow-up for the primary endpoint are complete. At that time, if there is a .80% probability that the most likely ED90 is better than placebo by the CSD, the trial will be considered a success. R, randomization

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