Trial of ARO-MAPT-SC in Healthy Participants and Participants With Early Alzheimer's Disease or Primary Tauopathies

What this study involves

The registry says this study is recruiting. Individual locations may have different availability.

Study type

Interventional

Phase

Phase 1 / Phase 2

Age range

18 years - Not specified

Sex eligible

All sexes

Healthy volunteers

Accepted

Participants

160 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

Trial to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of ARO-MAPT-SC compared to placebo in adult healthy volunteers and in participants with early Alzheimer's disease (AD), defined as mild cognitive impairment due to AD and mild AD dementia, as well as primary tauopathies, including microtubule associated protein tau -related frontotemporal dementia (MAPT-FTD) and progressive supranuclear palsy- Richardson syndrome (PSP-RS).

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

Inclusion Criteria (All Participants):

• Body mass index between 18.0 and 35.0 kilograms (kg)/square meter (m\^2) at Screening
• Not pregnant or breast-feeding
• Able and willing to provide written informed consent prior to the performance of any trial specific procedures
• Participants of childbearing potential must agree to use highly effective contraception in addition to a condom during the trial and for at least 90 days following the end of the trial or last dose of trial drug, whichever is later; participants must not donate sperm or eggs during the trial and for at least 90 days following the end of the trial or last dose of trial drug whichever is later

Inclusion Criteria (Early AD):

• Adults aged 50 to ≤80 years of age with a clinical diagnosis of early AD and plasma, CSF, or imaging biomarkers consistent with the diagnosis
• If participant is on non-disease-modifying AD medications, the doses must be stable for ≥8 weeks prior to Screening.

1. Participants with early AD are not required to be on AD medications.
2. Participants previously treated or currently receiving anti-amyloid therapies, including lecanemab and donanemab, are not eligible.

Inclusion Criteria (MAPT-FTD)

• Adults ≥18 years of age with Clinical Dementia Rating plus National Alzheimer's Coordinating Center Frontotemporal Lobar Degeneration-Neuropsychiatric and Motor domains Sum of Boxes Global Score of 0.5 or 1 at Screening
• Frontotemporal Lobar Degeneration (F-causative MAPT mutation, based on source verifiable medical records.
• If the participant is on medications for symptomatic management of MAPT-FTD, the doses must be stable for ≥8 weeks prior to Screening.

Inclusion Criteria (PSP-RS)

• Adults ≥41 to ≤86 years of age with clinical diagnosis of probable PSP-RS phenotype as defined by the 2017 Movement Disorder Society criteria (Höglinger 2017) with symptom onset ≥40 to ≤85 years of age
• Presence of PSP symptoms ≤3 years at Screening (occurring newly and subsequently progressing during the clinical course in the absence of another identifiable cause) as determined by the Investigator
• Mini-Mental Status Examination (MMSE) score of 20 to 30 (inclusive) at Screening
• Able to walk at least 10 steps with minimal assistance (eg, one arm for safety, but not postural support)
• Reside at home or in the community (assisted living is acceptable); outside of a skilled nursing facility or dementia care facility at the time of screening, with no planned admissions to such a facility at time of Screening.
• If the participant is on medications for symptomatic management of PSP-RS, the doses must be stable for ≥8 weeks prior to Screening.

Inclusion Criteria (AD and primary tauopathies)

• Have a reliable and competent caregiver or trial partner who is ≥18 years of age, able and willing to accompany the participant to trial visits involving informant-based assessments, to be available to site staff by telephone as needed, and in the opinion of the Investigator, be sufficiently familiar with the participant throughout the trial in order to provide accurate and reliable information relevant to trial outcome measures

Exclusion Criteria (All Participants):

• Blood pressure outside of specified range in the protocol
• Human immunodeficiency virus (HIV) infection (seropositive at Screening)
• Seropositive for hepatitis B (HBV) or hepatitis C (HCV) at Screening
• Intellectual disability or significant behavioral neuropsychiatric manifestation
• Clinically significant cardiac, liver, or renal disease
• Any contraindications to lumbar puncture
• Known allergy or possible allergy to either ARO-MAPT-SC or to its excipients

Note: Additional inclusion/exclusion criteria may apply per protocol.

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Random assignment

Masking

Quadruple masked

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (4)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

4 locations

Study team and timeline

Lead sponsor

Arrowhead Pharmaceuticals

Study start

Nov 18, 2025 Actual

Primary completion

2027-06 Estimated

Study completion

2027-06 Estimated

First posted

Oct 27, 2025 Actual

Last updated

Nov 10, 2026 Actual

Official study contacts