Anti Amyloid Leqembi denied for failing step therapy by Aetna?

Aetna's specific coverage criteria for anti amyloid leqembi are defined in its own published medical/coverage policy and the FDA-approved prescribing label. A successful appeal documents that your medical records satisfy each criterion those sources list — confirmed diagnosis, any required prior treatments (with dates and outcomes), and clinical severity. If the exact criteria weren't included with your denial, request them in writing; your appeal then maps each requirement to the matching fact in your chart.

## Why Aetna Requires Step Therapy for Leqembi — and Why You Can Appeal

Leqembi (lecanemab) targets the underlying amyloid pathology of Alzheimer's disease — a distinct mechanism from older symptomatic agents. Aetna's step-therapy (or "fail-first") requirement typically demands documented trial and failure of one or more prior medications before it will cover a disease-modifying therapy. For an anti-amyloid agent this structure is clinically problematic: symptomatic treatments and disease-modifying treatments address different aspects of the disease, and delay of disease-modifying therapy may result in irreversible progression.

## Why This Denial Is Appealable

Many states have step-therapy exception laws that require insurers to waive step-therapy when (a) the required prior drug is clinically contraindicated or inappropriate, (b) the patient has already tried and failed it, or (c) the step-therapy requirement is not consistent with the applicable clinical practice guideline. Federal law under ACA §2719 and ERISA §503 requires a full internal appeal and access to independent external review. You typically have 180 days from the denial to file internally, and the external review window is approximately four months from exhaustion of internal appeals. Expedited review is available when delay would cause serious deterioration.

## What to Gather

• Diagnosis and staging records: Amyloid confirmation (PET or CSF), cognitive testing, and clinical staging documents establishing early-stage Alzheimer's disease — the indicated population.
• Prior treatment history: Dates, doses, and outcomes of any prior Alzheimer's medications tried, with reasons for discontinuation or inadequate response.
• Clinical contraindication or inappropriateness documentation: If the required step-therapy drug is inappropriate for this patient, the prescriber must explain why in writing with reference to the patient's clinical profile.
• Prescriber medical-necessity letter: Explain why lecanemab is necessary now, why delay of disease-modifying therapy is harmful given disease stage, and cite the relevant guideline organization's recommendations.

## Criteria-Mapping Approach

Request Aetna's step-therapy policy for Leqembi in writing. List each requirement. For each required prior step, document whether it was completed (with outcome) or why it is not clinically appropriate for this patient. If the patient's disease stage makes further delay harmful, quantify that clinically. Reference the relevant neurology guideline organizations — without citing specific numbers — to establish that lecanemab is the standard-of-care option for confirmed early Alzheimer's disease at this stage.