Ert Pompe denied as duplicate or overlapping therapy by AmeriHealth Caritas?

Confirmed enzyme assay + genetic testing. Specialist Rx (geneticist or metabolic).

EPSDT for under-21 overrides state PDL limits. Orphan Drug Act + FDA approval rebut 'experimental' label. Site-of-care: home infusion appropriate for stable patients per manufacturer REMS.

## Why AmeriHealth Caritas Denies ERT for Pompe Disease as Duplicate Therapy

Enzyme replacement therapy (ERT) for Pompe disease — alglucosidase alfa (Lumizyme/Myozyme) or avalglucosidase alfa (Nexviazyme) — is sometimes denied under a "duplicate therapy" rationale when a patient appears to be receiving, or to have an active authorization for, another drug in the same therapeutic category. In Pompe disease, this denial typically occurs in one of two scenarios: (1) a payer system records both an older-generation and a newer-generation ERT as active at the same time during a transition; or (2) the patient participates in a patient-assistance or clinical program that the payer records as a separate coverage source, triggering a coordination-of-benefits or duplication flag.

Importantly, switching from one ERT to another — for example, from alglucosidase alfa to avalglucosidase alfa — is not duplicate therapy. These are distinct products with different pharmacological profiles. A prescriber decision to transition a patient from one ERT to another is a clinical decision, not concurrent duplicate administration.

## Federal Appeal Rights

A duplicate-therapy denial is an adverse benefit determination subject to the full appeal process under ACA Section 2719 (ACA marketplace and compliant plans) and ERISA Section 503 (employer-sponsored plans). AmeriHealth Caritas Medicaid and CHIP plans are governed by state Medicaid appeal regulations, which provide their own parallel rights — including a state fair hearing. External review rights apply to commercial plans. Expedited review is appropriate given that Pompe disease (particularly infantile-onset) can progress rapidly without ERT.

## Appeal Process and Timeline

1. Clarify the duplicate claim — request from AmeriHealth Caritas the specific drug it considers duplicative and the authorization or claim record it is relying on. 2. Administrative correction — if the duplication flag is an error (e.g., a stale prior authorization), work with the prescriber's office to cancel the outdated record and resubmit. 3. Clinical distinction letter (if transitioning ERTs) — the prescriber should document that the two ERTs are not interchangeable and that the transition is a medical decision, not concurrent duplicate use. 4. Internal appeal — address the specific duplicate-therapy determination with documentation. Expect a decision within 30 days (non-urgent) or 72 hours (expedited). 5. External review / state fair hearing — available after internal exhaustion.

## Documentation to Gather

• Current prescription and administration records: confirming what ERT the patient is actually receiving, with dates, and that prior-generation ERT has been discontinued if transitioning.
• Prescriber letter: explaining why the transition to a different ERT is a distinct clinical decision, not duplicate administration, and citing the FDA-approved prescribing labels for each product.
• Diagnosis confirmation: genetic testing confirming GAA gene variants consistent with Pompe disease; enzyme activity assay.
• Authorization records: copies of any prior authorizations on file, including dates of expiration, to demonstrate no concurrent active coverage exists.

## Criteria-Mapping Structure

Pull AmeriHealth Caritas's duplicate-therapy policy from the denial letter or the published coverage policy library. Map each criterion to the clinical facts: (1) Is the same drug being billed twice? — no; (2) Is there concurrent active authorization for the same drug? — demonstrate with authorization records; (3) Are these clinically interchangeable drugs? — cite the prescribing labels showing distinct indications, formulations, and clinical profiles if transitioning products.