[O4–03–01]: MAINTENANCE OF COGNITIVE IMPROVEMENT TREATMENT RESPONSE WITH MEMANTINE AND DONEPEZIL: POST HOC ANALYSES FROM A PLACEBO‐CONTROLLED STUDY IN PATIENTS WITH MODERATE TO SEVERE ALZHEIMER's DISEASE. (1st July 2017) - Atri, Alireza; Cummings, Jeffrey L.; Hendrix, Suzanne; Ellison, Noel; Andersen, Kristen A.; Edwards, John