Abstract This application requests supplemental funds for the funded grant, 1 R01 AG074447-01, which supports a first-in-human clinical trial of CMS121, a drug candidate for treatment of Alzheimer's Disease. Since the date of submission of the application for the parent grant, modifications have become necessary. Two of the modifications optimize the information obtained from the trial and the third provides an NIA-mandated Data and Safety Monitoring Board (DSMB). These modifications were unanticipated at the time of submission of the parent grant application. Celerion's clinical trial budget has been amended primarily to address the additional costs associated with shifting the elderly cohort from the single ascending dose (SAD) protocol to the multiple ascending dose (MAD) protocol, a change that provides multiple advantages. Celerion's separate budget for methods development now includes additional costs due to the necessity for an additional protocol to provide accurate measurements of CMS121 and three CMS metabolites in plasma and urine. Another unanticipated increase in costs results from the NIA requirement that a DSMB be established for all clinical trials funded by NIA, including Phase I trials. The major enhancement in the trial design and the necessary improvement in the measurements CMS121 and CMS121 metabolites in plasma and urine will provide valuable data that would otherwise be missed. Furthermore, these data will be directly relevant for the design of the next phase clinical trial for CMS121. The NIA-required DSMB will provide NIA staff additional oversight of the trial's progress.