Creator: Help Dementia Editorial Team
Published: 2026-04-12T02:37:56

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.

Expanded access sits at the center of this dementia and brain health question.

Yes, expanded access pathways are now available for experimental Alzheimer’s treatments, and they’re becoming more accessible than ever. Two FDA-approved monoclonal antibodies—lecanemab (Leqembi) and donanemab (Kisunla)—have created new routes for eligible patients to access disease-modifying treatments. These aren’t theoretical options anymore: as of January 2025, lecanemab can be administered as a weekly self-injection at home, and the FDA is expected to approve at-home starter doses by May 2026.

For someone like a 65-year-old with mild cognitive impairment and confirmed amyloid pathology in the brain, these pathways mean access to treatments that can slow cognitive decline—something that wasn’t possible five years ago. The landscape has shifted significantly because the FDA, CMS (Centers for Medicare & Medicaid Services), and the medical community have streamlined how these treatments reach patients. Instead of waiting years for traditional approval or being limited to clinical trial enrollment, eligible patients can now access these antibodies through Medicare coverage, accelerated approval pathways, and innovative delivery methods. Understanding these pathways—and what they require—is essential for anyone with early Alzheimer’s disease, their families, and their care teams.

HOW HAS THE FDA APPROVED MONOCLONAL ANTIBODIES FOR ALZHEIMER’S?
MEDICARE COVERAGE AND THE REGISTRY REQUIREMENT—WHAT YOU NEED TO KNOW
NEW DELIVERY METHODS—LECANEMAB NOW AVAILABLE AS A HOME INJECTION
PRACTICAL PATHWAYS—HOW TO ACCESS THESE TREATMENTS
AMYLOID-RELATED IMAGING ABNORMALITIES—A CRITICAL SAFETY CONSIDERATION
DONANEMAB’S UNIQUE MAINTENANCE APPROACH—PAUSE AND ASSESS
CLINICAL TRIALS EXPANDING ACCESS—2026 AND BEYOND
Conclusion

HOW HAS THE FDA APPROVED MONOCLONAL ANTIBODIES FOR ALZHEIMER’S?

The FDA has approved two amyloid-targeting monoclonal antibodies through accelerated and traditional approval pathways. Lecanemab received accelerated approval on January 22, 2023, followed by full traditional approval on July 13, 2023, based on evidence that it slowed cognitive decline in people with mild cognitive impairment or mild dementia due to Alzheimer’s disease with confirmed amyloid pathology. Donanemab followed with initial U.S. approval in 2024, offering an alternative option for patients in similar disease stages. The distinction matters: accelerated approval gets beneficial drugs to patients faster based on surrogate markers, while traditional approval provides longer-term safety and efficacy data—lecanemab has now completed both pathways.

What makes these approvals truly meaningful is the specificity of who can access them. These aren’t treatments for anyone experiencing memory problems; they’re limited to people with mild cognitive impairment (MCI) or mild dementia due to Alzheimer’s disease with confirmed amyloid pathology in the brain. This requirement exists because the clinical trials demonstrated benefit in these populations. A patient with moderate or advanced dementia would not be eligible for these treatments under current FDA approvals, even though they might desperately want access. Similarly, someone with cognitive complaints but no confirmed amyloid pathology wouldn’t qualify, which is why PET imaging or biomarker testing is part of the access pathway.

HOW HAS THE FDA APPROVED MONOCLONAL ANTIBODIES FOR ALZHEIMER'S?

MEDICARE COVERAGE AND THE REGISTRY REQUIREMENT—WHAT YOU NEED TO KNOW

Medicare’s Coverage with Evidence Development (CED) decision in April 2022 opened the door for coverage of FDA-approved monoclonal antibodies, but it came with a significant requirement: patients must enroll in approved registries that track real-world treatment outcomes. This isn’t bureaucratic red tape—it’s how CMS ensures these expensive treatments (which can cost $25,000+ annually) are actually helping patients in everyday practice, not just in controlled clinical trials. For someone on Medicare, this registry enrollment is mandatory to access coverage, which means working with a healthcare provider who participates in the approved registries. The registry requirement reveals an important limitation: not all healthcare settings are equipped to participate.

A patient in a rural area might have difficulty accessing a participating neurologist or memory clinic. Additionally, registry data collection adds administrative burden on patients and providers—appointments may take longer because of the paperwork and assessment scales required. Some patients find this intrusive or inconvenient, and a few providers have dropped out of registry programs because of the administrative load. However, the registry data has also provided invaluable real-world evidence showing that these treatments work outside of controlled trial settings, which justifies continued coverage.

NEW DELIVERY METHODS—LECANEMAB NOW AVAILABLE AS A HOME INJECTION

In January 2025, the FDA approved a game-changing delivery method: weekly subcutaneous (under-the-skin) maintenance dosing of lecanemab via autoinjector, making it the first amyloid-clearing antibody available as a self-administered injection at home. Previously, patients had to visit an infusion center every two weeks for intravenous administration—a significant time and logistical commitment. Now, a patient can inject the medication at home weekly, similar to how someone with diabetes self-administers insulin. This is a practical breakthrough for working-age patients and those in rural areas without convenient access to infusion centers.

The same month also brought approval for once-every-four-weeks maintenance dosing of lecanemab, expanding flexibility for patients already on treatment. However, a critical caveat: the at-home injectable form is currently only available for people already established on lecanemab therapy. The FDA decision on approving initial starter doses for home use is expected in May 2026. This means patients will still need at least one in-person visit to an infusion center to begin treatment, which is necessary because the loading phase of lecanemab requires medical monitoring due to the risk of amyloid-related imaging abnormalities (ARIA)—a type of brain inflammation or microhemorrhages visible on MRI. Once stabilized, patients can transition to home injections.

NEW DELIVERY METHODS—LECANEMAB NOW AVAILABLE AS A HOME INJECTION

PRACTICAL PATHWAYS—HOW TO ACCESS THESE TREATMENTS

Accessing these treatments requires a sequence of steps that involves multiple healthcare providers and confirmatory testing. First, a patient needs a cognitive assessment—typically with a neurologist or geriatrician—to confirm they have mild cognitive impairment or mild dementia due to Alzheimer’s disease. Second, they need confirmation of amyloid pathology, which can be determined either through amyloid PET imaging (a specialized brain scan) or through blood biomarkers like phosphorylated tau or plasma phospho-tau variants. This biomarker testing has expanded access significantly: blood tests are easier, faster, and less expensive than PET scans, and most insurance now covers them.

Once eligibility is confirmed, the patient’s physician prescribes the treatment and arranges enrollment in an approved registry (if on Medicare or certain insurance plans). The first infusions or injections typically occur in a medical setting where adverse reactions can be monitored. After the loading phase, patients transition to maintenance dosing—either continuing in-clinic infusions every four weeks, or, for lecanemab, potentially switching to weekly home injections. The entire pathway typically takes 2-4 weeks from initial assessment to first treatment, which is rapid compared to the years many patients waited before these approvals existed.

The most important limitation of these treatments is the risk of amyloid-related imaging abnormalities (ARIA), which include amyloid-related imaging abnormalities-edema (ARIA-E, brain swelling) and amyloid-related imaging abnormalities-microhemorrhages (ARIA-H, microscopic brain bleeds). In clinical trials, lecanemab caused ARIA-E in roughly 21% of treated patients versus 9% in the placebo group, though most cases were asymptomatic and detected on routine MRI monitoring. Some patients with ARIA-E experienced cognitive decline, headaches, or vision changes, and a small number required hospitalization. This isn’t a reason to avoid treatment, but it’s a reason to enter these therapies with eyes open and with a provider experienced in monitoring for these complications.

Regular MRI monitoring is non-negotiable: patients on lecanemab typically undergo brain MRI at 7 months into treatment and then annually afterward. This costs money and time, and some patients with claustrophobia or metallic implants face barriers to MRI. Additionally, certain people are at higher risk for ARIA: those with the APOE4 genetic variant (which increases Alzheimer’s risk) have higher ARIA rates, and older patients may face higher risks as well. Your physician should discuss these risks clearly and monitor you closely during the first year of treatment. The good news: most ARIA cases are manageable with dose adjustments or temporary treatment pauses, and symptom resolution occurs in the majority of cases.

AMYLOID-RELATED IMAGING ABNORMALITIES—A CRITICAL SAFETY CONSIDERATION

DONANEMAB’S UNIQUE MAINTENANCE APPROACH—PAUSE AND ASSESS

Donanemab offers an interesting alternative maintenance strategy compared to continuous lecanemab therapy. After 12-18 months of treatment, patients on donanemab who show a negative amyloid PET scan (meaning amyloid has been cleared from the brain) can pause the medication. This is fundamentally different from lecanemab, which is typically continued indefinitely once started. The pause-and-assess model appeals to many patients because it removes long-term medication burden and reduces lifetime costs and exposure to ARIA risks.

However, the question of whether pausing is truly safe remains partially unanswered; long-term durability data beyond the trial period is still being collected. For patients choosing donanemab, the initial treatment phase involves biweekly infusions for the first 8 weeks, then monthly infusions. Like lecanemab, it requires confirmed amyloid pathology and eligibility criteria of MCI or mild dementia due to AD. The choice between donanemab and lecanemab often depends on personal factors: some patients prefer the idea of a defined treatment window with donanemab, while others prefer the more established long-term data for lecanemab or the newer home injection option for lecanemab.

CLINICAL TRIALS EXPANDING ACCESS—2026 AND BEYOND

The treatment landscape is expanding further with ongoing clinical trials. The AHEAD Study is testing lecanemab in cognitively normal people who are at high risk for Alzheimer’s disease (typically defined by positive amyloid PET scans or biomarkers but no cognitive symptoms). If successful, this trial could eventually expand access pathways to include asymptomatic individuals—meaning prevention rather than treatment. Results from this trial are expected in the coming years and could reshape who becomes eligible for these therapies.

Additionally, remternetug, a next-generation anti-amyloid drug with both IV and injectable formulations, is in late-stage trials. A March 2026 readout was expected for trial results from over 1,600 participants comparing IV and injectable versions against placebo. These new drugs could offer additional options—potentially with better tolerability, lower ARIA rates, or more convenient dosing schedules. However, remternetug is not yet approved, and access will depend on FDA decisions and subsequent coverage determinations from Medicare and private insurers.

Conclusion

Expanded access pathways for experimental Alzheimer’s treatments have become a clinical reality, transforming what was once a disease without disease-modifying options into one with multiple FDA-approved choices. Lecanemab and donanemab are now covered by Medicare and many private insurers for eligible patients with mild cognitive impairment or mild dementia due to Alzheimer’s with confirmed amyloid pathology. The recent approval of at-home injectable lecanemab represents a major quality-of-life improvement, and further innovations—including potential approval of home starter doses by May 2026 and next-generation drugs on the horizon—continue to expand access and options.

If you or a loved one has been diagnosed with mild cognitive impairment or mild dementia due to Alzheimer’s disease, the next step is to discuss these treatments with a neurologist or memory care specialist. Bring up the specific question of amyloid pathology confirmation and whether you meet eligibility criteria. Ask about the monitoring requirements, potential risks of ARIA, and whether your healthcare provider participates in Medicare registries or has experience administering these medications. The expanded access pathways exist now—understanding them and accessing them early in the disease process is where the real benefit lies.