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Study of RO7126209 safety and effects given by intravenous infusion in patients with early stage or mild to moderate Alzheimer's disease

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients with Alzheimer's Disease, including those with early signs (prodromal) and mild to moderate forms of the condition. The study will test a new medication called RO7126209 (trontinemab), which is given through intravenous infusion. Some participants will receive the study medication while others will receive a placebo.

The main purpose of this research is to determine if RO7126209 is safe and well-tolerated when given in multiple increasing doses, and to understand how the medication works in the body. The study will also examine how the drug affects the buildup of amyloid (a protein associated with Alzheimer's Disease) in the brain using special brain scans called PET scans.

During the study, participants will receive multiple doses of either the study medication or placebo through an infusion into their vein. The study consists of four parts, with different dosing schedules in each part. Throughout the study, participants will undergo various medical examinations, including brain scans, blood tests, and assessments of their thinking abilities. Their safety will be closely monitored through regular check-ups and tests.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial evaluation

    Your eligibility will be assessed based on the following criteria:

    - Age between 50 and 85 years

    - Diagnosis of early or moderate Alzheimer's disease

    - Score of 18-28 points on the Mini-Mental State Examination

    - Positive brain scan showing amyloid protein buildup performed within the last 12 months

  2. Step 2

    Treatment groups assignment

    You will be randomly assigned to receive either:

    - Trontinemab through intravenous infusion (medication delivered directly into your vein)

    - Placebo (a substance with no active medication)

    The assignment is double-blind, meaning neither you nor your doctor will know which treatment you receive

  3. Step 3

    Brain imaging procedures

    Throughout the study, you will undergo:

    - Brain scans using Florbetapir F18 to measure amyloid protein levels

    - MRI (Magnetic Resonance Imaging) scans to monitor brain safety

  4. Step 4

    Monitoring and assessments

    Regular check-ups will include:

    - Physical and neurological examinations

    - Blood tests

    - Heart monitoring (ECG)

    - Vital signs measurements

    - Collection of spinal fluid samples to measure medication levels

  5. Step 5

    Study duration

    The study continues until September 2027

    Your participation may include multiple doses of the study medication

    Regular monitoring will continue throughout your participation to ensure safety

Who can join the trial?

6 criteria

  • Must be between 50 and 85 years old at the time of screening
  • Must have either: - Mild to moderate Alzheimer's disease with clear symptoms, or - Early signs of Alzheimer's disease with mild memory problems
  • Must score between 18 and 28 points on the Mini-Mental State Examination (a test that evaluates memory and thinking abilities) within 84 days before starting the study
  • Must have a Clinical Dementia Rating score of 0.5, 1, or 2 (a scale that measures the severity of dementia symptoms) within 84 days before starting the study
  • Must have a positive brain scan showing presence of amyloid (a protein associated with Alzheimer's disease) within 12 months before starting the study
  • If currently taking medications for Alzheimer's symptoms, the dose must have remained unchanged for at least 8 weeks before starting the study and must stay the same until assigned to a treatment group

Who cannot join the trial?

17 criteria

  • Age under 18 years old
  • Pregnancy or breastfeeding
  • History of severe allergic reactions to medications
  • Participation in another clinical trial within the past 30 days
  • Significant liver disease (problems with liver function)
  • Significant kidney disease (problems with kidney function)
  • Uncontrolled high blood pressure
  • History of heart disease or heart attack in the past 6 months
  • Active or recent cancer within the past 5 years
  • History of blood clotting disorders
  • Severe psychiatric conditions that could interfere with the study
  • Use of medications that could interact with the study drug
  • Alcohol or drug abuse within the past year
  • Inability to provide informed consent
  • Major surgery planned during the study period
  • History of brain hemorrhage (bleeding in the brain)
  • Severe neurological conditions other than Alzheimer's disease
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Investigated drugs

RO7126209 is an investigational medication administered through intravenous infusion (given into a vein). It is being studied for the treatment of people with early stages of Alzheimer's disease, including those with prodromal (very early) and mild to moderate symptoms. The medication is being tested to understand how well the body tolerates it, how it moves through the body, and what effects it has on the disease process.

What is already known about the treatment

RO7126209 - An investigational medication administered through intravenous infusion, currently being studied in clinical trials for the treatment of Alzheimer's disease, specifically in patients with prodromal or mild to moderate stages of the condition. The drug is undergoing Phase IB/IIA testing to evaluate its safety, tolerability, and how it moves through and affects the body through multiple-ascending doses. While the exact molecular mechanism is still being investigated through the clinical trials, the medication is being assessed through a carefully controlled study design that includes comparison with placebo to determine its therapeutic potential in Alzheimer's disease treatment.

Investigated diseases

Alzheimer's disease - A progressive brain disorder that gradually destroys memory, thinking skills, and the ability to carry out simple tasks. The disease begins slowly and first affects parts of the brain that control memory, thinking, and language. Over time, symptoms get worse as more parts of the brain become affected. The disease causes brain cells to degenerate and die, leading to a decline in cognitive and behavioral functions. Changes in the brain may begin years before the first symptoms appear.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase ITrial ID2023-509678-52-00Protocol codeBP42155Estimated enrolment256 patientsSponsorF. Hoffmann-La Roche AG

sourced from the EU Clinical Trials Register and site verification

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