12:12 PM EDT, 04/29/2024 (MT Newswires) -- Annovis Bio ( ANVS ) shares tumbled 58% in recent Monday trading after the company's phase 2/3 study of buntanetap to treat mild to moderate Alzheimer's disease missed an efficacy endpoint "due to the limited number of patients and short trial duration."

Annovis said it plans to conduct a pivotal disease-modifying phase 3 trial in biomarker-positive early Alzheimer's patients.

"The next study will have a longer duration, improved design and be statistically powered to validate symptomatic improvement and disease-modification," the company said Monday in a statement.

Overall, buntanetap was safe and well tolerated, the company said. Annovis Bio ( ANVS ) reported a "significantly higher" rate of improvement in assessment scale-cognitive subscale 11 scores in each treatment dose relative to placebo.

The study found no statistically significant differences in two other endpoints, the company said.

Annovis Bio ( ANVS ) said it will report the data to the FDA and ask for an end-of-phase 2 meeting. "We expect to discuss the data with the FDA in the next two to three months and then move on to the next Phase III study to confirm and expand these findings in an 18-month disease-modifying trial," the company said.

Price: 7.51, Change: -10.50, Percent Change: -58.30