The Alzheimer’s drug pipeline has never been more active. As of 2025, 138 drugs are being evaluated in 182 clinical trials, targeting not just the amyloid plaques that have dominated research for decades, but at least 15 distinct disease processes including tau protein tangles, neuroinflammation, and metabolic dysfunction in the brain. Two drugs — lecanemab (Leqembi) and donanemab (Kisunla) — have already crossed the finish line with FDA approval for early Alzheimer’s disease, providing proof that disease-modifying treatment is possible.
The question now is what comes next, and the answer involves a genuinely diverse set of approaches. This article walks through the most significant candidates currently in clinical trials, explains what biological targets they pursue and why those targets matter, and gives an honest account of where each stands. That includes tau-targeting therapies, drugs that address brain metabolism, candidates repurposed from other conditions, and first-in-class treatments aimed at neuroinflammation. For families and caregivers trying to understand whether new options might become available in the next few years, this is a realistic picture of what the pipeline holds.
Table of Contents
- How Many Alzheimer’s Drugs Are Currently in the Pipeline and What Do They Target?
- What Has Changed Since the Approval of Lecanemab and Donanemab?
- Why Tau Has Become a Central Target in Next-Generation Alzheimer’s Research
- Beyond Amyloid and Tau — What Other Approaches Are Being Tested?
- Drug Repurposing — Can Existing Medications Be Adapted for Alzheimer’s?
- The Role of FDA Designations and What They Actually Mean
- What the Alzheimer’s Pipeline Means for Patients and Families in the Next Few Years
- Conclusion
- Frequently Asked Questions
How Many Alzheimer’s Drugs Are Currently in the Pipeline and What Do They Target?
The 2025 pipeline report published in Alzheimer’s & dementia counted 138 drugs across 182 clinical trials — a substantial increase from where the field stood even five years ago. The composition of that pipeline tells an important story about how research priorities have shifted. Small molecule disease-targeted therapies make up the largest share at 43 percent, followed by biological disease-targeted therapies at 30 percent. Cognitive enhancement drugs account for 14 percent, and drugs targeting neuropsychiatric symptoms — things like agitation, psychosis, and sleep disturbance — make up the remaining 11 percent. The disease-targeted categories are the ones most likely to change the trajectory of Alzheimer’s rather than simply manage symptoms. The shift away from a near-exclusive focus on amyloid is the defining feature of the current pipeline.
Researchers are now pursuing tau accumulation, synaptic dysfunction, mitochondrial failure, vascular contributions, and inflammatory pathways simultaneously. At least 15 distinct disease processes are being studied across these trials. That breadth is both a sign of scientific maturity and a practical hedge: after decades of amyloid-only strategies producing repeated late-stage failures, the field has accepted that Alzheimer’s is likely a multi-factorial disease that may require combination approaches to treat effectively. One limitation worth noting: a large and active pipeline does not translate directly into approved treatments. The historical attrition rate in Alzheimer’s drug development is among the highest in medicine. Many of the 138 drugs in trials will not complete Phase 3 or will fail to show sufficient benefit against their side effect profiles. Still, the sheer breadth of the current pipeline, and the two recent approvals serving as proof of concept, give researchers more reasons for cautious optimism than at any previous point.
What Has Changed Since the Approval of Lecanemab and Donanemab?
The FDA approval of lecanemab (marketed as Leqembi, developed by Eisai and Biogen) and donanemab (Kisunla, Eli Lilly) marked a genuine turning point. Both are anti-amyloid immunotherapies — monoclonal antibodies that clear amyloid beta plaques from the brain — and both showed statistically significant slowing of cognitive decline in early-stage disease. Lecanemab received a notable regulatory update in 2025: the FDA approved a once-monthly maintenance dosing regimen on January 26, 2025, followed by approval of weekly subcutaneous (under-the-skin) maintenance dosing on August 29, 2025. The subcutaneous option in particular may improve accessibility, since earlier treatment required regular IV infusions at specialized centers. These approvals matter for the broader pipeline in two ways. First, they confirm that removing amyloid can have a measurable clinical effect — which was genuinely uncertain until recently.
Second, they raise the bar for every subsequent drug. Any new candidate has to demonstrate meaningful benefit beyond what these existing treatments provide, or target a patient population that anti-amyloid therapies don’t serve well. However, both lecanemab and donanemab come with significant caveats. Both are approved only for early symptomatic Alzheimer’s, and both carry a risk of amyloid-related imaging abnormalities (ARIA), a form of brain swelling or microbleeding that requires monitoring with regular MRIs. People taking blood thinners face higher ARIA risk, making these drugs unsuitable for a substantial portion of the older population who are the most likely candidates. This treatment gap — people with moderate or advanced disease, or those who can’t tolerate anti-amyloid therapies — is one reason the rest of the pipeline matters.
Why Tau Has Become a Central Target in Next-Generation Alzheimer’s Research
If amyloid was the focus of the last two decades, tau is increasingly the focus of the next. The protein tau forms neurofibrillary tangles inside neurons, and the spread of those tangles through the brain correlates more closely with cognitive decline than amyloid plaque burden does. Despite this, no tau-targeted therapy has yet received FDA approval — though several are in trials, and 2025 and 2026 have been described within the research community as a potential turning point. Among the candidates, ARO-MAPT from Arrowhead Pharmaceuticals takes a notably different approach. Rather than an antibody that clears existing tau, ARO-MAPT is an RNA interference therapy — it works by silencing the gene that produces tau in the first place, reducing the amount of tau the brain makes rather than attempting to clear it after it has accumulated.
A Phase I/IIa trial launched for both Alzheimer’s and other tauopathies, making it relevant beyond Alzheimer’s to conditions like progressive supranuclear palsy and frontotemporal dementia. Other tau candidates in trials include semorinemab, zagotenemab, and BIIB080, each using different mechanisms to interfere with tau pathology. Merck’s MK-2214 received FDA Fast Track Designation, a status granted to drugs that treat serious conditions and fill an unmet need, and data from this candidate was showcased at the Clinical Trials on Alzheimer’s Disease (CTAD) conference in 2025. Fast Track status accelerates the FDA review process and allows for more frequent communication between the developer and the agency, but it does not guarantee approval or indicate that efficacy has been established. It signals regulatory interest and expedited review, not a proven outcome.
Beyond Amyloid and Tau — What Other Approaches Are Being Tested?
Some of the most scientifically interesting work in the pipeline targets mechanisms that have little to do with protein aggregation. T3D-959, developed by T3D Therapeutics, is an oral, once-daily small molecule that activates PPAR-delta and PPAR-gamma receptors — nuclear receptors that regulate how cells process glucose and lipids. The underlying premise is that Alzheimer’s involves a form of metabolic dysfunction in the brain, sometimes characterized informally as insulin resistance in neural tissue. By restoring more normal glucose and lipid metabolism, T3D-959 aims to address an upstream driver of neurodegeneration rather than clearing protein deposits that may already be the result of years of metabolic stress. This drug is currently in Phase 2b/3 testing for mild-to-moderate Alzheimer’s — a population that anti-amyloid therapies don’t currently serve. THN391, developed by Therini Bio, takes yet another angle. It is a first-in-class monoclonal antibody targeting fibrin-mediated neuroinflammation.
When the blood-brain barrier breaks down — a process that occurs in Alzheimer’s — fibrin from the blood leaks into brain tissue and triggers an inflammatory response that damages neurons. THN391 is designed to block that pathway specifically. It is currently in Phase 1b evaluating safety and tolerability, which means it is at an early stage and may be several years from any approval even if results are positive. The tradeoff between these novel mechanisms and the existing anti-amyloid drugs is worth understanding. Drugs like lecanemab target a well-validated pathway and are already approved, but they work only in early disease and carry real safety considerations. Metabolic and anti-inflammatory approaches like T3D-959 and THN391 are less proven but potentially applicable to a broader patient population — including those with moderate disease who currently have limited options. Whether these approaches modify the actual disease course or simply address contributing factors remains to be established in larger trials.
Drug Repurposing — Can Existing Medications Be Adapted for Alzheimer’s?
One of the more unconventional entries in the pipeline is AR1001, developed by AriBio, a compound originally developed for erectile dysfunction. The drug is a phosphodiesterase inhibitor that, in earlier studies, appeared to have neuroprotective and potentially disease-modifying effects. AriBio is currently running a Phase 3 trial enrolling more than 1,500 participants to test whether AR1001 can modify the disease course in early Alzheimer’s. Results are expected in the second half of 2026, making this one of the most closely watched near-term readouts in the field. Drug repurposing has practical advantages: the compound’s safety profile in humans is already established, which can shorten development timelines and reduce certain regulatory hurdles.
The risk, however, is that effects observed in earlier, smaller studies don’t hold up in larger controlled trials. The history of Alzheimer’s drug development includes several promising compounds — some repurposed, some novel — that showed early signals only to fail at Phase 3. A 1,500-person trial is large enough to detect a genuine disease-modification effect if one exists, which makes the AR1001 data expected in late 2026 meaningful regardless of outcome. A broader warning applies to anyone following pipeline news: Phase 2 results in Alzheimer’s research have historically been poor predictors of Phase 3 outcomes. The disease’s complexity, the difficulty of identifying the right patient populations, and the long timelines involved mean that even well-funded, well-designed trials frequently fail. That is not a reason to dismiss the pipeline — the two recent approvals demonstrate that success is possible — but it is a reason to interpret early-stage results cautiously.
The Role of FDA Designations and What They Actually Mean
Several pipeline drugs carry FDA Fast Track, Breakthrough Therapy, or Accelerated Approval designations. These are frequently reported as major milestones, and they are worth understanding correctly. Fast Track Designation, like the one granted to Merck’s MK-2214, expedites the development and review process for drugs treating serious conditions with unmet need.
It does not mean the drug works. Breakthrough Therapy Designation is a higher bar — it requires preliminary clinical evidence suggesting the drug may offer substantial improvement over existing treatments — but it also does not guarantee approval. Accelerated Approval, the pathway used for lecanemab’s initial approval before full clinical data were available, allows approval based on a surrogate endpoint (in lecanemab’s case, amyloid reduction) that is reasonably likely to predict clinical benefit, with full confirmation required in post-approval trials. This pathway has been debated within the research community, but for patients with early Alzheimer’s, it made a treatment available years sooner than traditional approval would have allowed.
What the Alzheimer’s Pipeline Means for Patients and Families in the Next Few Years
The period from 2026 through 2028 is likely to bring several important data readouts that will clarify which of the current pipeline candidates have a genuine future. AR1001’s Phase 3 results are expected in the second half of 2026. Tau-targeting therapies are advancing through trials. Metabolic approaches like T3D-959 are in late-stage testing. Whether any of these reach approval within the next few years depends on trial outcomes that are not yet known.
What is already true is that the field looks different than it did five years ago. Two approved disease-modifying drugs exist. The pipeline is broader and more mechanistically diverse than at any previous point. Research into combination therapies — the idea that Alzheimer’s may need to be treated with multiple drugs simultaneously, similar to how HIV and certain cancers are treated — is gaining ground. For families navigating a diagnosis today, the practical options remain limited and the approved drugs come with real constraints. But for those in early stages who qualify, and for those watching the pipeline for future options, 2026 is a more consequential year in Alzheimer’s research than most that have come before it.
Conclusion
The Alzheimer’s drug pipeline in 2025 and 2026 represents a genuine expansion in both scale and scientific approach. With 138 drugs in 182 trials, two recently approved anti-amyloid therapies, and a wave of tau-targeting, metabolic, and anti-inflammatory candidates moving through clinical testing, the field has more meaningful activity than at any previous point. Lecanemab’s expanded dosing options, donanemab’s approval, and the Fast Track designation for Merck’s MK-2214 all reflect a regulatory environment that is actively engaging with this research.
For anyone affected by Alzheimer’s — whether personally or as a caregiver — the most useful takeaway is that the pipeline is real and progressing, but timelines are long and outcomes are uncertain. Early-stage disease currently has approved options worth discussing with a neurologist. For moderate and advanced disease, the pipeline candidates targeting metabolism, inflammation, and tau represent the best current hopes, with several key data readouts expected before the end of 2026. Staying informed through reputable sources — the Alzheimer’s Association, Being Patient, and peer-reviewed research — remains the most reliable way to track what actually becomes available.
Frequently Asked Questions
Are lecanemab and donanemab available to everyone with Alzheimer’s?
No. Both are approved only for early symptomatic Alzheimer’s disease — specifically mild cognitive impairment or mild dementia due to Alzheimer’s. They are not approved for moderate or advanced stages. Additionally, both carry risks of brain swelling and microbleeding that make them unsuitable for people on blood thinners or with certain other health conditions.
What does “disease-modifying” mean in the context of Alzheimer’s drugs?
A disease-modifying drug is one that changes the underlying biological course of the disease, not just its symptoms. For Alzheimer’s, this typically means slowing the accumulation of amyloid or tau, or protecting neurons from damage. Lecanemab and donanemab are considered disease-modifying because they clear amyloid and have shown statistically significant slowing of cognitive decline — though the clinical magnitude of that slowing has been debated.
What is the significance of tau-targeting therapies?
Tau tangles correlate more closely with cognitive decline than amyloid plaques do, which makes tau an important target. No tau-targeting drug has been approved yet, but several are in trials. If any of these succeed, they could either complement anti-amyloid therapies or provide an alternative for patients who can’t tolerate them.
What is RNA interference and why does it matter for Alzheimer’s?
RNA interference (RNAi) is a mechanism that silences specific genes. ARO-MAPT uses RNAi to reduce the brain’s production of tau protein from the source, rather than clearing tau after it has already formed tangles. This is a fundamentally different approach from antibody-based therapies and is being watched closely for both Alzheimer’s and related conditions like progressive supranuclear palsy.
When will we know if AR1001 works?
AriBio’s Phase 3 trial of AR1001, enrolling more than 1,500 participants with early Alzheimer’s, is expected to report results in the second half of 2026. This is one of the most significant near-term data readouts in the pipeline.
How is the Alzheimer’s pipeline funded?
Funding comes from multiple sources: pharmaceutical companies, the National Institutes of Health (NIH), the Alzheimer’s Association, and various public-private partnerships. The National Institute on Aging has substantially increased Alzheimer’s research funding in recent years, which has contributed to the growth in pipeline activity.
