Acasti Pharma said its krill oil-derived drug candidate, CaPre, was not more effective than placebo in reducing high levels of triglycerides in a late-stage study.
US-listed shares of Acasti were down 54 per cent at $1 before the bell.
The Canada-based drug developer said CaPre failed to show a statistically significant reduction in blood triglycerides compared to placebo after 12 weeks and 26 weeks of treatment.
Triglycerides are a type of fat found in blood that contributes to heart disease alongside cholesterol.