Latest in Alzheimer’s (Spring 2026)

Spring 2026 Alzheimer’s Disease Updates: Blood Tests, Anti-Amyloid Treatments, Prevention Research, and What Families Should Know

Last updated: April 25, 2026

Overview

Alzheimer’s disease care is entering a new phase. The field is moving away from diagnosing AD by symptoms and MRI alone, and toward biomarker-confirmed Alzheimer’s disease using amyloid PET, cerebrospinal fluid (CSF) testing, and increasingly blood-based biomarkers. At the same time, the first disease-modifying anti-amyloid treatments are now part of real-world neurology practice, although their benefits are modest, their risks require careful monitoring, and they are appropriate only for selected patients with early-stage, amyloid-confirmed Alzheimer’s disease.

In 2026, the Alzheimer’s Association estimates that approximately 7.2 million Americans age 65 and older are living with Alzheimer’s disease (and roughly 7.4 million when younger-onset cases are included). About 1 in 9 people age 65 and older has AD, and the number is projected to nearly double by 2050.

The biggest Alzheimer’s updates heading into May 2026 are:

  • Two FDA-cleared blood tests for AD diagnosis are now available, but they have important limitations and are not stand-alone screening tests. The Lumipulse pTau217/Aβ42 plasma test was placed under an FDA Class II recall in early 2026 due to false-positive concerns with specific manufacturing lots.

  • Leqembi® and Kisunla™ remain the only FDA-approved disease-modifying therapies for early Alzheimer’s disease. Long-term data show their benefit accumulates over 3–4 years for patients who continue treatment, although a major Cochrane review published in April 2026 concluded the class effect on cognition is “trivial,” prompting active debate in the field.

  • The FDA has a May 24, 2026 target action date for a proposed at-home weekly subcutaneous starting dose of Leqembi (the maintenance subcutaneous form is already approved). The decision is still pending as of late April 2026.

  • ARIA monitoring has become more stringent — MRI is now recommended before the 3rd, 5th, 7th, and 14th Leqembi infusions.

  • Research is broadening beyond amyloid, with brain-shuttle antibodies (trontinemab), tau-targeted therapies, prevention trials, and lifestyle data (U.S. POINTER, July 2025) all advancing.

Understanding Alzheimer’s Disease

Alzheimer’s disease begins long before symptoms appear, often 10–20 years in advance. The disease primarily affects the brain through:

  • Amyloid plaques: Abnormal clumps of amyloid-beta protein outside brain cells.

  • Tau tangles: Twisted strands of tau protein inside neurons. Tau pathology correlates more closely than amyloid with the rate of clinical decline, which is why tau is now the next major drug target.

  • Neuroinflammation and brain shrinkage (atrophy): Chronic inflammation and oxidative stress eventually cause brain cells to die.

Early (Prodromal) Symptoms

  • Slight memory lapses (forgetting recent conversations or appointments)

  • Mild trouble finding words, managing finances, or planning

  • Depression, anxiety, apathy, irritability, or sleep disturbances

Main Symptoms

  • Significant memory loss affecting daily activities

  • Difficulty solving problems or performing familiar tasks

  • Confusion about dates, times, or locations

  • Language difficulties

  • Mood and personality changes (anxiety, suspicion, agitation)

How We Diagnose Alzheimer’s Disease in 2026

A careful Alzheimer’s evaluation in 2026 is layered — first ruling out reversible or alternate causes of cognitive change, then determining whether AD biology is actually present.

Initial Evaluation

  • Detailed history and neurological exam

  • Bedside cognitive screening (MoCA or MMSE)

  • Blood tests for reversible contributors (vitamin B12, thyroid, etc.)

  • MRI (preferred) or CT to identify structural abnormalities

  • Standardized neuropsychological testing for baseline and progression tracking

Blood-Based Biomarker Testing — Major 2025–2026 Developments

Blood-based AD biomarkers are one of the biggest practical advances in the field, but they require careful interpretation.

Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio (Fujirebio) — Cleared by the FDA on May 16, 2025, this was the first blood test cleared to aid AD diagnosis in symptomatic patients age 55+. In validation, concordance with amyloid PET or CSF was about 92% (positive) and 97% (negative), with about 20% of results falling in an indeterminate range that still requires PET or CSF confirmation.

⚠️ Important 2026 update: The FDA posted a Class II recall on specific Lumipulse pTau217/Aβ42 lots in early 2026, after data presented at the December 2025 CTAD conference showed unexpectedly high false-positive rates (up to ~40% in one Mayo Clinic cohort) likely linked to a manufacturing issue. Fujirebio is releasing corrected lots. This reinforces that blood tests must be interpreted in clinical context and confirmed with PET or CSF when treatment decisions depend on the result.


Elecsys pTau181 (Roche) — FDA-cleared October 13, 2025. This is the first blood-based AD biomarker cleared for use in the primary care setting, intended to help rule out AD-related amyloid pathology (97.9% negative predictive value in a 312-participant study). A negative test argues against amyloid pathology and may avoid unnecessary PET or CSF testing; a positive or borderline test should prompt specialist referral and confirmatory testing. The test is now available through major reference laboratories including Labcorp.

Bottom line on blood tests: They are useful, increasingly accessible, and rapidly improving, but they are adjunctive — not stand-alone diagnostic or screening tools. The Alzheimer’s Association published its first clinical practice guideline for blood-biomarker use in specialty settings in 2025, and similar guidance for primary care is in development.

Imaging and CSF Testing

  • Amyloid PET remains an important confirmatory test. CMS removed the prior national coverage restriction for beta-amyloid PET in 2023, allowing local Medicare contractors to make coverage decisions; access still varies by region and payer.

  • Tau PET with the FDA-approved tracer TAUVID® (flortaucipir F 18) is approved for estimating the density and distribution of tau neurofibrillary tangles in adults being evaluated for AD. Real-world access and insurance coverage remain variable, but tau PET is increasingly used to stage disease and identify patients most likely to benefit from anti-amyloid therapy.

  • CSF testing (lumbar puncture) for amyloid and tau biomarkers remains a valid option, particularly when blood tests are indeterminate or unavailable.

  • 3T NeuroQuant MRI provides quantitative volumetric analysis of brain structures, useful for tracking atrophy patterns over time.

  • APOE genotype testing is recommended before anti-amyloid therapy. APOE ε4 carriers — particularly homozygotes — have higher ARIA risk and require careful counseling.

Treatment and Management

Symptomatic Therapies (Oral)

  • Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) — modest symptomatic benefit. Donepezil is best taken in the morning rather than at night, to minimize sleep disruption.

  • Memantine — used for moderate-to-severe AD; modulates glutamate signaling.

Disease-Modifying Therapies for Early Alzheimer’s Disease

These therapies are appropriate only for patients with mild cognitive impairment or mild dementia due to AD with confirmed amyloid pathology. They do not cure AD or reverse symptoms; they are designed to modestly slow progression in carefully selected early-stage patients. The decision to start treatment requires honest discussion of expected benefit, ARIA risk, monitoring burden, cost, and the patient’s goals.

Leqembi® (Lecanemab)

Regulatory status:

  • Accelerated FDA approval Jan 2023; full approval July 2023.

  • Monthly IV maintenance (after the initial 18-month phase) approved January 2025.

  • Subcutaneous maintenance (Leqembi IQLIK™ 360 mg weekly autoinjector) approved August 2025.

  • A proposed subcutaneous starting dose is under FDA Priority Review with a PDUFA action date of May 24, 2026. As of late April 2026, the decision is still pending. If approved, this would allow at-home initiation of treatment from day one, eliminating the IV induction phase for many patients.

Dosing:

  • Initial phase (first 18 months): IV every 2 weeks (current standard).

  • Maintenance phase (after 18 months): Either monthly IV or weekly 360 mg subcutaneous injection at home (≈15 seconds with the IQLIK autoinjector).

  • MRI monitoring: Before the 3rd, 5th, 7th, and 14th infusions; most ARIA events occur within the first 6 months.

Efficacy:

  • 18-month CLARITY-AD: 27% slowing of CDR-SB decline; 31% lower risk of progressing to the next disease stage.

  • 4-year extension data (presented in 2025): roughly 1.75–2.17 CDR-SB point benefit vs. matched ADNI/BioFINDER natural-history cohorts. In low-tau (earlier-stage) subgroups, many patients showed no measurable decline over 4 years.

ARIA risk:

  • ARIA-E ~13%, ARIA-H ~17%; combined ~21%.

  • Higher in APOE ε4 carriers, especially homozygotes.

  • Most ARIA is asymptomatic but can rarely be serious or fatal.

Kisunla™ (Donanemab)

Regulatory status: Full FDA approval July 2024. Modified titration schedule (TRAILBLAZER-ALZ 6) was added to the label in July 2025, lowering early ARIA-E risk while preserving efficacy.

Dosing: Monthly IV with titration over the first several doses. Treatment can be stopped once amyloid PET drops below threshold — Kisunla is the only anti-amyloid therapy with a defined stopping rule. MRI is required at baseline and before the 2nd, 3rd, 4th, and 7th infusions.

Efficacy:

  • 18-month TRAILBLAZER-ALZ 2: 29% slowing of decline overall; up to 36% at the earliest disease stage; 37% lower risk of progressing to the next stage.

  • 3-year long-term extension: CDR-SB difference vs. ADNI grew from –0.6 at 18 months to –1.2 at 36 months. Earlier initiation outperformed delayed start. (These are externally controlled comparisons, not continuous head-to-head placebo data, which is an important caveat.)

ARIA risk:

  • Original titration: combined ARIA-E/H ~37%; symptomatic ARIA ~6%.

  • Modified TRAILBLAZER-ALZ 6 titration: ARIA-E roughly halved (~14% at 24 weeks vs. ~24%), with similar amyloid clearance.

A Balanced View of Anti-Amyloid Therapy in 2026

A patient-facing page should not over-promise. In April 2026, a Cochrane systematic review (Nonino et al.) of 17 trials and 20,342 participants concluded that the class of amyloid-beta–targeting monoclonal antibodies “probably results in little to no difference” in cognitive function, dementia severity, or functional ability at 18 months, and that any effect was “trivial” by clinical standards. The review covered nine drugs collectively, including aducanumab, bapineuzumab, crenezumab, gantenerumab, ponezumab, remternetug, solanezumab, lecanemab, and donanemab.

Major Alzheimer’s organizations and dementia researchers have pushed back, noting the review pooled multiple failed first-generation antibodies alongside the two newer agents (lecanemab and donanemab) that regulators have judged to have a modest but meaningful benefit. The UK MHRA, U.S. FDA, and EMA have all concluded that newer agents differ meaningfully from earlier failed antibodies. The U.K.’s NICE has so far declined NHS reimbursement and is currently reassessing.

The most accurate way to explain this to families is: these medications are not cures and do not improve memory in most patients. They are designed to modestly slow decline in carefully selected patients at the early stage of AD. Whether the benefit is worth the risks, cost, monitoring burden, and uncertainty is an individualized decision that should be made by the patient, family, and a neurologist familiar with their specific situation.

Research Advances to Watch in 2026

Trontinemab — Roche’s “Brain Shuttle” Antibody

Trontinemab uses a transferrin-receptor-binding “brain shuttle” fragment to pull an anti-amyloid antibody across the blood-brain barrier roughly 50× more efficiently than conventional antibodies. In Phase 1b/2a Brainshuttle AD data presented at AAIC and CTAD 2025:

  • About 91% of patients on the 3.6 mg/kg dose became amyloid-PET negative within 28 weeks.

  • Plaque cleared in deep brain regions (hippocampus, caudate) that conventional antibodies penetrate poorly.

  • ARIA-E was under 5% — substantially lower than current therapies.

Phase 3 TRONTIER 1 and TRONTIER 2 began enrolling in late 2025 (≈800 participants each). A separate PrevenTRON Phase 3 trial is planned in preclinical (asymptomatic) AD. If pivotal results confirm Phase 2 findings, regulatory submission could come in 2028. Larger, longer trials are needed before we know whether the better-looking biomarker effects translate to better real-world clinical outcomes and whether the safety advantage holds up.

Anti-Tau Therapies — First Clinical Signals (and Setbacks)

The tau field has had a difficult few years, with several O-GlcNAcase inhibitors (LY3372689/ceperognastat, ASN51, BIIB113) halted in 2025 and Johnson & Johnson’s anti-tau antibody posdinemab failing its pivotal trial. But second-generation tau antibodies are now showing biological and early clinical signals:

  • Bepranemab (UCB) — Phase 2 TOGETHER trial (n=466) was the first tau-directed therapy to show a clinical signal. It slowed tau-PET accumulation 33–58% and slowed ADAS-Cog14 decline 21–25% at 80 weeks. The primary CDR-SB endpoint was not met overall, but predefined subgroups (low baseline tau, APOE ε4 non-carriers) showed consistent benefit. Larger trials are planned.

  • Etalanetug (E2814, Eisai) — Anti-MTBR tau antibody. In dominantly inherited AD (DIAD), it reduced CSF MTBR-tau243 by 75–89% and showed stabilization of tau-PET. Now being tested in Tau NexGen (Phase 2/3, in DIAN-TU, paired with lecanemab) and Study 202 (Phase 2, sporadic early AD, also paired with lecanemab) — these are the first major combination amyloid + tau trials in AD.

  • BIIB080 — antisense oligonucleotide that lowers tau production; in Phase 2 trials with data expected in 2026.

Prevention Trials

  • AHEAD 3-45 — lecanemab in cognitively unimpaired adults with intermediate or elevated amyloid.

  • TRAILBLAZER-ALZ 3 — Donanemab in cognitively normal adults with elevated amyloid; uses plasma p-tau217 to screen.

  • DIAN-TU Tau NexGen — combination therapy in autosomal-dominant AD mutation carriers.

  • PrevenTRON — planned trontinemab prevention trial.

If any of these read out positive over the next 2–3 years, AD treatment moves toward a true prevention paradigm — treating people before symptoms ever appear.

Lifestyle: U.S. POINTER

In July 2025, the U.S. POINTER trial results were published in JAMA. In 2,111 older adults at increased dementia risk, a structured 2-year multidomain lifestyle intervention (combining physical exercise, nutrition, cognitive and social engagement, and heart-health monitoring) produced greater global cognitive gains than a self-guided program. Both groups improved overall. The benefit held across sex, ethnicity, APOE genotype, and baseline heart-health status. This does not replace medical evaluation or disease-modifying therapy when appropriate, but it reinforces that vascular risk control, exercise, diet, sleep, hearing correction, and social/cognitive engagement remain central to brain health.

A Notable Negative Result: Semaglutide

In November 2025, Novo Nordisk announced that the EVOKE and EVOKE+ Phase 3 trials of oral semaglutide in early symptomatic AD did not meet their primary endpoint of slowing disease progression. This is a useful reminder to wait for randomized trial data before adopting “incidental benefit” claims from observational studies of metabolic drugs.

Conditions That Can Look Like Alzheimer’s

Before committing to an AD diagnosis (or AD-directed treatment), it is essential to consider:

  • Reversible or partly reversible contributors: thyroid disease, B12 deficiency, sleep apnea, depression, medication effects (anticholinergics, sedatives), alcohol use, hearing/vision loss

  • Vascular cognitive impairment

  • Lewy body disease, Parkinson’s disease dementia

  • Frontotemporal dementia

  • TDP-43 / LATE — frequently coexists with AD pathology in older adults

  • Normal pressure hydrocephalus

  • Cerebral amyloid angiopathy

These distinctions matter because they change prognosis, treatment options, and especially eligibility for anti-amyloid therapy.

The Best Alzheimer’s Care in 2026 Is Staged and Individualized

  1. Confirm the syndrome. Is this a true progressive cognitive disorder, or is something else (sleep, mood, medication, hearing loss, vascular disease, thyroid, B12, etc.) contributing?

  2. Confirm the biology. Is Alzheimer’s pathology actually present? Use blood biomarkers, PET, CSF, and tau imaging as appropriate to the stage and the question being asked.

  3. Confirm the treatment window. Anti-amyloid therapy is for early-stage AD only — not moderate or advanced dementia. The decision requires careful review of ARIA risk, APOE genotype, MRI findings, anticoagulation, comorbidities, logistics, and patient goals.

  4. Combine medical therapy with the fundamentals. Exercise, vascular risk control, sleep, hearing correction, nutrition, cognitive and social engagement, medication review, fall prevention, caregiver support, and advance care planning.

Bottom line: Alzheimer’s treatment is improving, but the field is still early. The major advance is that we can now diagnose AD more biologically and discuss disease-modifying treatment for selected early-stage patients. The next wave of progress will likely come from better blood tests, safer delivery systems, tau-targeted therapies, prevention trials, and combination approaches.

At Los Altos Neurology, we provide personalized evaluation, advanced diagnostic testing (including the new plasma biomarker tests with appropriate confirmatory follow-up), and access to the latest disease-modifying therapies, including Leqembi (IV and SC maintenance) and Kisunla. We help families decide whether these options are right for them and coordinate safe monitoring throughout treatment.