CurrentBlue Cross Blue Shield - IowaPolicy 05.04.54

Firdapse (amifampridine) — Coverage Criteria for Lambert‑Eaton Myasthenic Syndrome

Covers clinical coverage criteria and prior authorization requirements for Firdapse (amifampridine) to treat Lambert‑Eaton myasthenic syndrome (LEMS) for Wellmark/Blue Cross Blue Shield - Iowa members.

Policy Summary

PayerBlue Cross Blue Shield - Iowa

PolicyFirdapse (amifampridine) — Coverage Criteria for LEMS

Policy CodePolicy 05.04.54

Change TypeNo material changes

Effective DateJan 28, 2026

Next Review DateJan 28, 2026

Key ActionObtain prior authorization with documented diagnostic confirmation (EMG showing required CMAP change or positive anti‑P/Q antibody) and evidence of proximal muscle weakness.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

6 monthsInitial auth

12 monthsContinuation auth

240/30dQuantity limit

>=6 yrsFDA age

Specialty requiredPrescriber

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Coverage Criteria for Firdapse (amifampridine)

Initial Therapy

Covered when ALL of the following are met

Initial approval criteria for LEMS: A. Diagnosis is confirmed by either: (1) EMG showing compound muscle action potential (CMAP) that increased at least 2‑fold after maximum voluntary contraction of the tested muscle, OR (2) a positive anti‑P/Q type voltage‑gated calcium channel antibody test; B. Member has proximal muscle weakness.EMG >= 2-fold CMAP increase OR positive anti-P/Q antibody

Initial approval will be for 6 months

Continuation Therapy

Covered when ALL of the following are met

Continuation therapy criteria for LEMS: Member is responding to therapy, defined as stability or improvement in symptoms relative to the natural course of LEMS.response or stability documented

Authorization of 12 months may be granted for continued treatment

Coverage will not be provided for members with a history of seizures. This exclusion applies to requests for Firdapse (amifampridine) and must be confirmed during prior authorization review; members with documented seizure history should be denied coverage per policy language.

Procedures, Codes, and Key Clinical Codes

Procedures and billing codes (general instruction)mixed

No codes listed

EMG CMAP increase

EMG criterionCMAP that increased at least 2‑fold after maximum voluntary contraction of the tested muscle

Test typeElectromyography (EMG) showing compound muscle action potential (CMAP)

ContextUsed as diagnostic confirmation for LEMS to qualify for initial 6‑month authorization

Minimum age for FDA indication

Minimum age6 years of age and older

FDA-approved populationAdults and pediatric patients 6 years and older

Policy implicationMembers younger than 6 years not covered under the FDA indication

Prior Authorization, Documentation, and Exclusions

Prior Authorization

Prior Authorization Required

Prior authorization is required. Initial approval may be granted for up to 6 months for treatment of Lambert-Eaton myasthenic syndrome (LEMS) when diagnostic confirmation is provided (see Documentation callout).

Initial approval: up to 6 months
Condition: Lambert-Eaton Myasthenic Syndrome (LEMS)

Documentation Required

Required Diagnostic Documentation

Submit documentation of one of the following diagnostic tests to initiate prior authorization review: an Electromyography (EMG) showing compound muscle action potential (CMAP) OR a positive anti‑P/Q type voltage‑gated calcium channel antibody test.

EMG showing CMAP (see LEMS diagnostic criteria: CMAP that increases ≥2-fold after maximum voluntary contraction)
Anti‑P/Q type voltage‑gated calcium channel antibody: positive result

Denial Risk

Exclusion — Seizure History

Coverage will not be provided for members with a history of seizures.

Background

Firdapse (amifampridine) is indicated for the treatment of Lambert‑Eaton myasthenic syndrome (LEMS) in adults and pediatric patients 6 years and older. Authorization for initial therapy may be granted for 6 months when diagnostic confirmation and proximal muscle weakness are documented; continuation authorizations of 12 months may be granted for members who demonstrate stability or improvement on therapy. Diagnostic confirmation can include electromyography (EMG) showing a compound muscle action potential (CMAP) that increases by at least 2‑fold after maximum voluntary contraction or a positive anti‑P/Q type voltage‑gated calcium channel antibody test.

Definitions

LEMS — Lambert-Eaton myasthenic syndrome (LEMS)

TermLambert‑Eaton myasthenic syndrome (LEMS)

IndicationFirdapse (amifampridine) indicated for treatment of LEMS

Authorization noteInitial authorization may be granted for 6 months when diagnostic confirmation and proximal muscle weakness are documented

Diagnostic confirmation (EMG or antibody)

EMG evidenceEMG showing CMAP that increased at least 2‑fold after maximum voluntary contraction

Antibody evidencePositive anti‑P/Q type voltage‑gated calcium channel antibody test

Use for prior authorizationSubmit either EMG (with specified CMAP increase) or positive anti‑P/Q antibody to initiate prior authorization review