THN391 for people with early Alzheimer's disease and small vessel disease

A Double-blind, Randomized, Placebo-controlled, Phase 1b Study to Assess the Safety, Tolerability and Pharmacokinetics of Multiple Ascending Doses of THN391 in Early Alzheimer's Disease Subjects

Phase 1 Interventional Therini Bio, Inc. · NCT06814730

We will test monthly doses of THN391 to see if they are safe and how the drug behaves in people aged 65–85 with early Alzheimer's disease and cerebral small vessel disease.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment15 (estimated)
Ages65 Years to 85 Years
SexAll
SponsorTherini Bio, Inc. Industry-sponsored
Locations4 sites (Amsterdam, New Hampshire and 3 other locations)
Trial IDNCT06814730 on ClinicalTrials.gov

What this trial studies

This is a Phase 1b, randomized, double-blind, placebo-controlled, multiple ascending dose trial enrolling people aged 65–85 with early Alzheimer's disease and cerebral small vessel disease. Participants will be randomized to receive one of several dose cohorts of THN391 or matching placebo given monthly for three doses, followed by a four-month follow-up, with roughly 13 clinic visits and two phone calls over 6–8 months. Safety, pharmacokinetics, pharmacodynamics, and immunogenicity will be measured through blood sampling, four brain MRIs, two lumbar punctures, ECGs, neurological exams, and cognitive/functional assessments. Dose cohort sizes may be adjusted or new cohorts added based on blinded interim data.

Who should consider this trial

Good fit: People aged 65–85 with a diagnosis of early Alzheimer's disease and cerebral small vessel disease who are medically stable, able to consent, and not taking full-dose anticoagulants (clopidogrel or low-dose aspirin allowed) are the intended participants.

Not a fit: Patients with moderate or severe dementia, other significant neurological or psychiatric disorders, large vessel disease, or those on prohibited anticoagulants are unlikely to qualify and would not be expected to benefit from this Phase 1 safety-focused study.

Why it matters

Potential benefit: If successful, THN391 could offer a new treatment approach targeting fibrin-related pathology that might slow disease processes linked to vascular contributions in early Alzheimer's disease.

How similar studies have performed: THN391 has been tested in healthy volunteers, but this is the first trial in Alzheimer's patients and fibrin-targeting therapies for AD remain largely preclinical or in very early clinical testing, so clinical benefit is unproven.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Be willing and able to understand the study procedures and the risks involved and provide written informed consent before the first study-related activity
* 65 to 85 years of age (inclusive at the time of informed consent).
* Diagnosis of Early Alzheimer's Disease (AD)
* Diagnosis of cerebral Small Vessel Disease (cSVD), and having at least one of the following vascular risk factors: hypertension, Type 2 diabetes mellitus, or hyperlipidemia

Exclusion criteria:

* Diagnosis of moderate or severe dementia
* Any other medical condition except for early AD (e.g. any clinically significant neurological, psychiatric or large vessel disease) that could affect interpretation of study assessments
* Use of anticoagulant, except for either clopidogrel or low dose aspirin, unless taken simultaneously

Where this trial is running

Amsterdam, New Hampshire and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Alzheimer Disease, Early OnsetEarly ADFibrinFibrinogenamyloid pathologyAlzheimer Disease
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.