A placebo-controlled pilot study of the ampakine CX516 added to clozapine in schizophrenia

CX516, a positive modulator of the glutamatergic alpha -amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor, improves performance in tasks requiring learning and memory in animals. CX516 was added to clozapine in 4-week, placebo-controlled, dose-finding (N = 6) and fixed-dose (N = 13) trials. CX516 was tolerated well and was associated with moderate to large, between-group effect sizes compared with placebo, representing improvement in measures of attention and memory. These preliminary results suggest that CX516 and other ampakines hold promise for the treatment of schizophrenia.