ProMIS Neurosciences announced a peer‑reviewed publication showing that plasma phosphorylated tau (pTau181 and pTau217) levels may predict later cognitive benefits in Alzheimer’s disease trials—strengthening the rationale behind its ongoing PRECISE-AD Phase 1b study with PMN310.
The cross‑trial analysis, conducted in collaboration with statistical‑research firm Pentara Corporation, examined summary data from several large monoclonal‑antibody Alzheimer’s trials. The study found a strong correlation—approximately 0.78—between group‑level changes in plasma pTau at six months and clinical outcomes at 12 months as measured by the Clinical Dementia Rating Sum of Boxes (CDR‑SB). Importantly, the magnitude of change in plasma pTau was about 2.6 times larger than the effect size seen on clinical scales, suggesting biomarker shifts may become detectable well before clinical improvement.
Simulations presented in the report indicate that early proof‑of‑concept trials could be significantly streamlined using plasma pTau as the primary endpoint. For drug candidates with efficacy comparable to leading monoclonal antibodies, adequately powered trials might require as few as ~100 participants.
For ProMIS, these findings reinforce the design of PRECISE-AD, which uses plasma pTau (including pTau217) as a central biomarker measure at 6 and 12 months. The company said this biomarker‑driven approach could yield an early, quantitative signal of drug effect—potentially accelerating dose selection and decision‑making for later‑stage trials.
ProMIS expects a blinded 6‑month biomarker readout from PRECISE‑AD in the second quarter of 2026, with top‑line data anticipated in the fourth quarter of 2026.
