Creator: Help Dementia Editorial Team
Published: 2026-04-02T12:49:27

Reviewed by the Help Dementia Editorial Team — our editors review every article for accuracy against guidance from the National Institute on Aging, the Alzheimer’s Association, and peer-reviewed sources.

Clinical trial sits at the center of this dementia and brain health question.

If you carry the APOE4 gene variant and are wondering whether there are clinical trials actively recruiting participants at no cost, the answer is yes—but you’ll want to know which specific trials are currently open. Several APOE4-focused trials are recruiting right now, including studies at Duke and UNC that examine gene therapy approaches for cognitive decline, and the PreventE4 trial which tests prevention strategies in cognitively healthy carriers. However, the landscape shifted significantly in August 2024 when the large APOLLOE4 Phase 3 trial (testing ALZ-801) completed enrollment ahead of schedule, meaning that particular study is no longer accepting participants.

This article covers the APOE4 trials that are actively recruiting today, how to find them, what to expect if you enroll, and the resources available to help you determine if participation is right for you. The APOE4 gene creates a measurably higher risk for Alzheimer’s disease—carriers of two APOE4 copies (APOE4 homozygotes) have up to eight times the baseline risk—making these trials particularly important for advancing dementia prevention and treatment research. The fact that multiple studies now exist with free or low-cost participation reflects growing recognition of this genetic risk group’s need for accessible research opportunities.

Which APOE4 Clinical Trials Are Currently Recruiting Without Cost?
What Happened to the APOLLOE4 Trial That Everyone Was Talking About?
Understanding the Duke/UNC Gene Therapy Approach for APOE4 Carriers
The PreventE4 Prevention Trial and Why Prevention Research Matters for Carriers
How to Find APOE4 Trials and Other Resources for Participation
What to Expect When You Enroll in an APOE4 Clinical Trial
The Future of APOE4-Specific Treatments and Ongoing Research Landscape
Conclusion

Which APOE4 Clinical Trials Are Currently Recruiting Without Cost?

The most prominent actively-recruiting trial is the Gene Therapy for APOE4 study, run through Duke University and the UNC Alzheimer’s Research and Care Center. This is an open-label, dose-ranging study designed specifically for APOE4 homozygotes (two copies of the gene) who have mild cognitive impairment or early-to-moderate Alzheimer’s dementia. The trial examines whether a gene therapy approach can modify the course of cognitive decline in people at the highest genetic risk. Because this is investigator-initiated research at academic medical centers, participant costs are minimal or covered by the research program itself. Alongside this, the PreventE4 trial (clinical trial identifier NCT03613844) continues recruiting cognitively unimpaired adults aged 55 to 80 who carry the APOE4 variant and have cardiovascular risk factors related to dementia.

This study tests whether docosahexaenoic acid (DHA) supplementation—an omega-3 fatty acid—can help prevent cognitive decline in at-risk carriers. Recruitment is still ongoing, and again, participation comes with no participant costs; in fact, baseline findings from this trial were published in The Journal of Prevention of Alzheimer’s Disease, underscoring its scientific credibility. The key difference between these two trials illustrates an important point: gene therapy studies tend to focus on people who already have cognitive symptoms, while prevention trials target cognitively normal carriers. If you are cognitively healthy with APOE4, PreventE4 is likely a fit. If you have mild memory complaints or early cognitive changes, the Duke/UNC gene therapy trial may be more appropriate.

Which APOE4 Clinical Trials Are Currently Recruiting Without Cost?

What Happened to the APOLLOE4 Trial That Everyone Was Talking About?

Until August 2024, the APOLLOE4 Phase 3 trial—which tested an oral drug called ALZ-801 (valiltramiprosale) in APOE4 homozygotes with early Alzheimer’s disease—was the largest and most anticipated APOE4-specific study running. Alzheon, the company developing the drug, announced that enrollment closed ahead of the original timeline, with 325 participants successfully enrolled across 93 clinical sites worldwide. This early completion actually reflects strong participant engagement and suggests the research community viewed the trial as sufficiently powered to answer its primary question. However, this is important to understand: if you were hoping to join APOLLOE4, that option is no longer available as of mid-2024. The trial moved from the recruitment phase into the data analysis phase.

Participants who are already enrolled will continue their follow-up visits as scheduled, but new enrollees are no longer being accepted. This is a common situation in clinical research—large Phase 3 trials have enrollment windows and deadlines, and they close once the target participant number is reached. The closure of APOLLOE4 does not mean APOE4 research has stalled. Rather, it reflects that this particular study cycle is complete, and the research community now shifts to analyzing results and—depending on outcomes—moving toward potential regulatory approval for ALZ-801. In the meantime, the other trials mentioned above continue recruiting, offering immediate options for those seeking to participate in cutting-edge APOE4 research.

Understanding the Duke/UNC Gene Therapy Approach for APOE4 Carriers

The gene Therapy for APOE4 trial represents a fundamentally different approach to APOE4-related Alzheimer’s than previous drug trials. Rather than attempting to slow cognitive decline with a small-molecule oral medication, gene therapy aims to modify the underlying genetic risk itself—or at least its downstream effects on the brain. This is a paradigm shift that has gained traction in neuroscience over the past five years as gene therapy technology has matured. Specifically, the Duke/UNC trial is enrolling APOE4 homozygotes with mild cognitive impairment (MCI) or mild-to-moderate Alzheimer’s dementia. Participants undergo cognitive testing, biomarker assessments (which may include brain imaging or cerebrospinal fluid tests), and receive the investigational gene therapy via a dose-escalating protocol.

The study is “open-label,” meaning both participants and researchers know who is receiving the treatment (unlike blinded trials where this is hidden). This transparency can be reassuring, but it also means results may be influenced by expectation effects, so robust follow-up studies would be needed before broad recommendations. An important caveat: gene therapy for neurological conditions is still in relatively early stages of development, and the safety profile and long-term durability of effects are not yet fully established. Participants must be comfortable with this uncertainty and willing to undergo frequent monitoring. That said, for APOE4 homozygotes with existing cognitive decline, the potential for a disease-modifying approach—one that targets the genetic root rather than just symptoms—represents a compelling research opportunity that doesn’t exist in routine clinical care.

Understanding the Duke/UNC Gene Therapy Approach for APOE4 Carriers

The PreventE4 Prevention Trial and Why Prevention Research Matters for Carriers

If you are an APOE4 carrier without cognitive impairment, the PreventE4 trial offers a different value proposition: the chance to participate in prevention research while you are still cognitively healthy. The trial focuses on DHA (docosahexaenoic acid), a long-chain omega-3 fatty acid found in fatty fish and algae supplements. Prior observational studies suggested omega-3 intake might help protect cognitive function in APOE4 carriers specifically, making this a hypothesis worth testing in a randomized controlled setting. PreventE4 is enrolling adults aged 55 to 80 with APOE4 and at least one cardiovascular risk factor (such as hypertension, diabetes, elevated cholesterol, or metabolic syndrome). The hypothesis is reasonable: cardiovascular disease and dementia share overlapping risk pathways, and vascular health is particularly important for APOE4 carriers.

By intervening with DHA in cognitively healthy carriers who also have vascular risk, researchers aim to answer whether early supplementation can prevent or delay cognitive decline. A key limitation to consider: unlike the gene therapy trial, PreventE4 tests a supplement, not a novel pharmaceutical agent. DHA is available over-the-counter and already used by many people. If you enroll, you will receive study-grade DHA under medical supervision with cognitive monitoring, which adds rigor compared to self-directed supplementation. However, if the trial results show benefit, the actual intervention you could pursue on your own might be as simple as increasing fish intake or taking a commercial omega-3 supplement—meaning you might not need to wait for regulatory approval to try this approach.

How to Find APOE4 Trials and Other Resources for Participation

If you do not already know your APOE4 status, you first need genetic testing. Several free or low-cost options exist. The National Institute on Aging’s GeneMatch Registry is one such pathway: this registry enrolls adults aged 55 to 75 and provides a free cheek swab kit by mail. After enrollment, you are informed of your APOE genotype and matched to relevant Alzheimer’s research studies, including APOE4-specific trials. This is a no-cost entry point if you are in the right age range and willing to mail in a sample. ClinicalTrials.gov is the U.S. government’s official registry of clinical trials.

You can search directly for “APOE4” and filter by recruitment status to find currently active trials, their contact information, and eligibility criteria in real time. This site is updated regularly and is more current than any article or news summary. For each trial, you will find the trial’s clinical site locations, contact details, and a detailed description of what participation entails. The Alzheimer’s Association also operates TrialMatch®, a free matching service that connects volunteers with dementia-related research studies. You answer questions about your demographic characteristics, cognitive status, and location, and the service returns a list of studies you may be eligible for. This service is less APOE4-specific than a targeted search on ClinicalTrials.gov, but it can be helpful if you are unsure which trials might accept you or want a one-stop resource. Note that not all trials use TrialMatch for recruitment, so searching ClinicalTrials.gov independently remains important.

How to Find APOE4 Trials and Other Resources for Participation

What to Expect When You Enroll in an APOE4 Clinical Trial

Before enrolling, understand what your time commitment will be. Trials involving APOE4 carriers with cognitive symptoms (like the gene therapy trial) typically involve baseline visits for cognitive testing, brain imaging, and sometimes lumbar puncture for cerebrospinal fluid biomarkers. Follow-up visits may occur monthly, quarterly, or annually depending on the trial phase and protocol. Prevention trials like PreventE4 typically have less intensive monitoring—perhaps cognitive testing once or twice per year plus study medication dispensing visits. There is also the question of what happens after the trial ends.

If you are in a study testing a novel drug or therapy, and the results are promising, you may be offered continuation access to the study drug through the trial sponsor. However, this is not guaranteed. Prevention trials using supplements or lifestyle modifications typically do not offer post-trial access in the same way because the interventions are already available commercially. Make sure to clarify this with the research team before you commit—knowing what comes next can help you decide whether a particular trial aligns with your expectations. Finally, understand that participating in research is voluntary and you can withdraw at any time without penalty. However, withdrawal may mean missing important follow-up data about your cognitive status, so the research team will typically ask you to complete at least a final assessment visit before exiting.

The Future of APOE4-Specific Treatments and Ongoing Research Landscape

The early closure of the APOLLOE4 Phase 3 trial, combined with continued recruitment in the gene therapy and prevention spaces, suggests that APOE4-specific research is entering a new phase. Instead of waiting for a single breakthrough drug, the field is diversifying into multiple mechanistic approaches: gene therapy, prevention interventions, and perhaps combination strategies that address both cardiovascular and neurological risk.

As of now, there is no FDA-approved drug specifically labeled for APOE4 carriers. The trials currently recruiting represent your earliest opportunity to access cutting-edge approaches before they become available through standard clinical practice. Over the next 3 to 5 years, as trials complete enrollment and move through analysis and regulatory review, some of these approaches may transition from research to treatment options available to the broader population of APOE4 carriers.

Conclusion

If you are an APOE4 carrier interested in participating in clinical research at no cost, your options include the Gene Therapy for APOE4 trial at Duke and UNC for those with cognitive decline, the PreventE4 trial for cognitively healthy carriers with vascular risk factors, and potentially other trials discoverable through ClinicalTrials.gov or the GeneMatch Registry and Alzheimer’s Association TrialMatch services. The specific trial implied by your question’s title does not appear in current registries, but these active alternatives represent the real landscape of free APOE4-focused research available to participants today.

Your next step is to determine your APOE4 status (if you do not already know it) and then identify which trial matches your cognitive status, age, location, and health profile. Contact the research teams directly through ClinicalTrials.gov or the trials’ institutional websites to discuss eligibility, time commitment, and what participation would mean for your long-term health management.