Sage Therapeutics is altering the primary endpoint of a Phase 2 study for its drug candidate dalzanemdor in cognitive impairment associated with Huntington’s disease, just months before trial results are expected.
The trial was originally focused on a six-segment composite cognitive assessment called the Huntington’s Disease-Cognitive Assessment Battery, or HD-CAB. Sage announced Wednesday that it will instead focus on one of that assessment’s subgroups looking at cognition, known as the symbol digit modalities test, or SDMT.
The study is expected to read out before the end of this year.
The change comes after a separate study last month showed only a “small numerical difference” between the dalzanemdor and placebo arms, Sage revealed in its second-quarter earnings press release. Sage described that trial as a “learning study,” CEO Barry Greene said during a follow-up call with investors Wednesday.
“We did a learning study, and we learned, and that learning is what we’re applying” to the study, Greene said.
In response to a separate question about whether Sage had consulted with the FDA about the change, Greene said that the company doesn’t comment on specifics about ongoing discussions with regulators.
Laura GaultCMO Laura Gault said Sage made the decision after seeing that some aspects of HD-CAB were “directionally positive” in spite of the small difference in the topline result. Gault added that Sage also discussed the move with Huntington’s patient organizations and other experts. Parts of the HD-CAB assessment will remain as secondary endpoints, but not the whole composite.
Wednesday’s news follows a spate of negative trial readouts for Sage. In April, the company discontinued the development of dalzanemdor in Parkinson’s disease after a Phase 2 study missed its primary and secondary endpoints. Another experimental treatment, SAGE-324, failed a Phase 2 trial in essential tremor earlier this month.
In addition to the Huntington’s study, Sage is testing dalzanemdor in a Phase 2 trial for Alzheimer’s disease, with a readout also expected before the end of the year.