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A phase 2 randomized, placebo-controlled study on the efficacy and safety of AR1001, a phosphodiesterase-5 inhibitor, in patients with mild-to-moderate Alzheimer's disease

Greeley D, Nash M, Herskowitz B, Kim F, Rock J, Prins N, Kim S, Xi T et al.

The journal of prevention of Alzheimer's disease, 2025

210 participants · 1 citation

Abstract

Background: AR1001 is a phosphodiesterase-5 inhibitor that produces improved cognitive performance and reduces amyloid-β and phosphorylated tau burdens in preclinical models of Alzheimer's disease (AD).

Objectives: To evaluate the safety and efficacy of AR1001 in participants with mild-to-moderate Alzheimer's disease (AD).

Design: Randomized, double-blind, placebo-controlled phase 2 trial conducted at 21 sites in the United States.

Participants: Adults aged 55-80 years with mild-to-moderate dementia as determined by National Institutes of Aging-Alzheimer's Association (NIA-AA) stage 4 or 5 and Mini-mental State Exam (MMSE) score 16-26.

Intervention: Once daily oral administration of placebo, 10 mg AR1001, or 30 mg AR1001 for 26 weeks followed by 26 weeks optional extension.

Measurements: Co-primary efficacy endpoints were changes from baseline at Week 26 in Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog 13) and Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC). Secondary endpoints included measures of cognition, daily living, and depression. Levels of plasma biomarkers pTau-181, pTau-217, Aβ42/40 ratio, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) were also examined.

Results: A total of 210 participants were enrolled and 82% completed 26 weeks of treatment. AR1001 10 mg and 30 mg were well-tolerated with a similar safety profile compared to placebo. After 26 weeks, there were no…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 210 participants or records.

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