Phase II DIMENSION trial of SAGE 718 (dalzanemdor) for cognitive impairment associated with Huntington’s Disease did not meet its primary endpoint

In the study, dalzanemdor did not demonstrate a statistically significant difference versus placebo on the primary endpoint, the change from baseline on the Symbol Digit Modalities Test (SDMT) at Day 84.

Analyses of secondary endpoints did not demonstrate statistically significant or clinically meaningful differences in participants treated with dalzanemdor compared to placebo. Based on these results, the Company does not plan further development of dalzanemdor.

“We are disappointed by the results of the DIMENSION Study, especially for the individuals and families affected by Huntington’s Disease who have long awaited new treatment options,” said Barry Greene, Chief Executive Officer, Sage Therapeutics. “Innovation is desperately needed, and we are immensely grateful to the participants, investigators, and the entire Huntington’s Disease community whose unwavering commitment to advancing research helped make this study possible.”

DIMENSION Study Results; The DIMENSION Study was a 12-week, double-blind, placebo-controlled Phase II study to evaluate the effects of dalzanemdor in participants with CI associated with HD. A total of 189 participants were randomized.. The DIMENSION Study did not demonstrate a statistically significant difference from baseline in participants treated with dalzanemdor versus placebo on the SDMT, a measure of cognitive function, at Day 84, the primary endpoint. Dalzanemdor was generally well-tolerated and no new safety signals were observed. The majority of treatment emergent adverse events were mild to moderate in severity. Analyses of secondary endpoints did not demonstrate statistically significant or clinically meaningful differences between the dalzanemdor and placebo treatment groups. Given these findings, the Company also will close the ongoing PURVIEW Study, an open-label safety study of dalzanemdor in participants with HD.