In 2026, at-home Leqembi still needs clinic MRIs to check for ARIA, or amyloid-related imaging abnormalities tied to brain swelling or bleeding. People with early Alzheimer's can ask an Alzheimer's specialist about MRI timing, genetic risk, and symptoms that should pause dosing. Leqembi is a prescription anti-amyloid treatment for early Alzheimer's with confirmed amyloid buildup.
According to BioArctic and Eisai, FDA approved 500 mg weekly at-home initiation on July 13, 2026, as two 250-mg injections BioArctic and Eisai announcement. According to Eisai and Biogen, FDA had approved 360 mg weekly maintenance in August 2025 after 18 months of IV lecanemab Eisai and Biogen press release. Neither option removes MRI and symptom checks.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What stays in the clinic when injections move home?
- When do MRIs happen?
- What is ARIA and how common is it?
- Does ApoE ε4 testing affect monitoring?
- Which symptoms should trigger a call and MRI?
What stays in the clinic when injections move home?
Home dosing moves the needle, not the oversight. A weekly autoinjector dose occurs at home. The specialist still orders MRIs, reads results, and decides about pausing or stopping. According to FDA, Leqembi is only for adults with mild cognitive impairment or mild dementia-stage early Alzheimer's with confirmed amyloid-beta pathology.
Ask whether memory testing, staging, and amyloid testing confirm that fit. Ask who coordinates scans and follow-up visits. According to Eisai and Biogen, at-home maintenance followed 18 months of IV treatment in the original approval. Initiation at home is newer, so ask how your clinic handles training and first-week checks. Ask these three things:.
- Am I eligible by stage and amyloid result?
- Who teaches injection and watches first doses?
- How do I reach the team after hours?
When do MRIs happen?
According to FDA safety communication, treatment needs a recent baseline brain MRI within one year before starting FDA drug safety communication. The same guidance calls for MRIs before the 5th, 7th, and 14th infusions. In August 2025, FDA added an earlier MRI between the 2nd and 3rd infusions to catch ARIA-E, the swelling type, sooner. Weekly shots do not use the same infusion count, so ask how your clinic maps those checkpoints.
According to the same FDA communication, the first 14 weeks need enhanced vigilance. Ask where each MRI will occur and who compares it with baseline. Use the visit to lock down logistics. Confirm timing, results, and backup plans.
- When is my baseline MRI still current?
- How are the 2nd-to-3rd, 5th, 7th, and 14th checks scheduled for weekly shots?
- What happens if a scan cannot be booked on time?
What is ARIA and how common is it?
According to FDA, labeling carries a boxed warning for ARIA. ARIA-E means edema or effusion, or swelling and fluid buildup. ARIA-H means hemorrhage, including tiny bleeds and surface iron deposits, and severe cases can be serious or fatal. According to Eisai prescribing information, Clarity AD Study 2 found ARIA in 21% on Leqembi versus 9% on placebo Eisai prescribing information.
ARIA-E occurred in 13% and ARIA-H in 17%. Symptomatic ARIA occurred in 3%, serious symptoms in 0.7%, and symptoms resolved in 79% during observation. Most ARIA has no symptoms, so scans matter even when you feel well. Ask how ARIA-E and ARIA-H look different on your reports. Ask what finding would pause dosing and what follow-up scan would follow.
Does ApoE ε4 testing affect monitoring?
ApoE ε4 is a gene variant linked to Alzheimer's risk. A test before treatment shows zero, one, or two copies. Two copies means homozygote, one copy means heterozygote. According to FDA, homozygotes have higher rates of symptomatic, serious, and severe ARIA than heterozygotes and noncarriers.
The result helps weigh benefit and risk before starting. Ask whether your copy number changes MRI timing or threshold for pausing. Do not start shots while gene results are still pending unless the specialist advises it. Clarify consent, privacy, and family meaning of the result. Ask these three things:.
- Have my results returned and what is my copy number?
- How does my result shape monitoring and pause rules?
- Should family members consider separate counseling?
Which symptoms should trigger a call and MRI?
According to FDA safety guidance, at-home dosing still needs close watch, especially in the first 14 weeks. Headache, confusion, vision changes, dizziness, nausea, or walking difficulty should prompt MRI review. The specialist may delay dosing or stop treatment based on findings.
Do not wait for a routine visit if new signs appear. Call promptly for: Keep a dated note of start times, shot days, headaches, and falls. Bring the MRI disk or portal access, drug list, and ApoE result to each check. Call the clinic the same day new brain symptoms appear, even on a shot day.
- new or severe headache
- confusion, trouble thinking, or vision change
- dizziness, nausea, or unsteady walking
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