Topline results from phase II PRECEDENT study of dalzanemdor (SAGE 718) in the treatment of mild cognitive impairment in Parkinson’s disease

The PRECEDENT Study did not meet its primary endpoint of demonstrating statistically significant difference from baseline in participants treated with once-daily dalzanemdor versus placebo on the Wechsler Adult Intelligence Scale Fourth Edition-IV (WAIS-IV) Coding Test score at Day 42. Dalzanemdor (SAGE-718) was generally well-tolerated, and there were no new safety signals observed.

“We are disappointed by the results of the Phase II PRECEDENT study given the significant burden of mild cognitive impairment on people and families affected by Parkinson’s Disease,” said Barry Greene, Chief Executive Officer at Sage Therapeutics. “We are thankful for the patients and healthcare professionals who participated in this research. Although cognitive impairment is common in neurodegenerative disorders, the underlying pathophysiology and symptomatology in Parkinson’s disease is distinctive, and these results do not necessarily predict results with dalzanemdor in other neurodegenerative conditions. We look forward to the topline data readouts from the Phase II studies in Huntington’s disease and Alzheimer’s disease expected later this year.”

PRECEDENT Study Results ; The PRECEDENT Study was a double-blind, placebo-controlled Phase II study in people with MCI in PD. The study is designed to evaluate the safety and efficacy of dalzanemdor (SAGE-718) dosed over 6 weeks. A total of 86 participants were enrolled and randomized. The PRECEDENT Study did not meet its primary endpoint of demonstrating statistically significant difference from baseline in participants treated with once-daily dalzanemdor versus placebo on the Wechsler Adult Intelligence Scale Fourth Edition-IV (WAIS-IV) Coding Test score at Day 42.

Dalzanemdor (SAGE-718) was generally well-tolerated, and there were no new safety signals observed. A total of 48 participants experienced treatment emergent adverse events (TEAEs). The vast majority of TEAES were mild to moderate in severity. Analyses did not suggest any meaningful differences versus placebo in the other exploratory endpoints such as SCOPA-Cog.

Based on the data, the Company does not plan any further development of dalzanemdor (SAGE-718) in PD.

The Company expects the following milestones for the dalzanemdor (SAGE-718) Phase II clinical development program in 2024: Mid-2024: Report topline data from SURVEYOR Study in people with HD cognitive impairment .Late 2024: Report topline data from LIGHTWAVE Study in people with MCI and mild dementia in AD. Report topline data from DIMENSION Study in people with HD cognitive impairment.