CurrentMass General Brigham Health PlanPolicy 072

Medical Necessity Guidelines — Elevidys (delandistrogene moxeparvovec)

Medical necessity and prior authorization criteria for Elevidys for Mass General Brigham Health Plan members across Medicare Advantage, Mass General Brigham ACO, One Care/SCO, and Commercial/Qualified Health Plans.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Necessity Guidelines — Elevidys (delandistrogene moxeparvovec)

Policy CodePolicy 072

Change TypeAdministrative / Clarifying

Effective DateApril 2024

Next Review Date

Key ActionObtain prior authorization and document NSAA and 6MWT within 3 months, anti-AAVrh74 titer <1:400, stable corticosteroid dosing, DMD mutation type, and specialist prescriber credentials.

SourceLink

POLICY UPDATE CHANGES

Reformatted policy and clarified Medicare Advantage section and criteria hierarchy in the One Care and SCO section; eligibility criteria moved to Medicare Advantage section.

Prime Therapeutics information added for Commercial and Qualified Health Plan prior authorization management.

4-5Age group considered medically necessary

6Minimum documented items required at baseline (NSAA + 6MWT + others)

<1:400Anti-AAVrh74 total binding antibody titer exclusion threshold (must be <)

>=200Minimum 6-minute walk test (6MWT) distance for coverage (meters)

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Medical Necessity / Coverage Criteria

Medical Necessity / Coverage Criteria (Mass General Brigham Health Plan)

Elevidys is covered when ALL of the following are met:

ALL of the following

Member is 4 or 5 years old
Diagnosis of Duchenne muscular dystrophy (DMD) with a disease-causing mutation in the DMD gene
Anti-AAVrh74 total binding antibody titer <1:400
Laboratory testing for anti-AAVrh74 total binding antibodies required
Member is on a stable corticosteroid dose
Stability of dose should be documented
Baseline functional measurements (must have both within past 3 months)
- North Star Ambulatory Assessment (NSAA) recorded, including scores and times on individual items
- Six-minute walk test (6MWT) recordedwithin past 3 months
Six-minute walk test (6MWT) distance ≥ 200 meters>= 200 meters
Appropriate dosing
Presumably per FDA labeling; dosing documentation required
Prescriber is a specialist in neuromuscular disease

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Exclusions / Not Covered

Elevidys is not covered when ANY of the following apply:

ANY of the following

Deletion in exon 8 or exon 9 of the DMD gene
Current active infection
Prior treatment with delandistrogene moxeparvovec
Current treatment with antisense oligonucleotides

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Relevant Codes

Elevidys HCPCS codeHCPCS

J1413

Injection, delandistrogene moxeparvovec-rokl, per therapeutic dose

Prior Authorization, Documentation, and Denial Risks

Prior Authorization

Prior authorization required

Prior authorization is required for Elevidys (HCPCS code J1413) for Medicare Advantage, Mass General Brigham ACO, One Care/SCO, and Commercial/Qualified Health Plan members; prior authorization for Commercial and Qualified Health Plan members is managed by Prime Therapeutics.

Affected code: J1413
Applicable payer segments: Medicare Advantage; Mass General Brigham ACO; One Care and SCO; Commercial and Qualified Health Plans (commercial PA managed by Prime Therapeutics)

Documentation Required

Baseline functional testing and antibody titer documentation

Document baseline functional testing and antibody titer for J1413: record NSAA scores (including times for individual items) and a 6MWT within the past 3 months, document anti-AAVrh74 total binding antibody titer <1:400, document stability of corticosteroid dosing, DMD mutation type, and that the prescriber is a neuromuscular disease specialist.

Clinical Background

Elevidys (delandistrogene moxeparvovec) is an AAVrh74-based gene therapy that delivers a transgene encoding a micro-dystrophin protein intended to replace the function of the mutated DMD gene in patients with Duchenne muscular dystrophy (DMD). The product received FDA approval for use in ambulatory patients aged 4 years and older with a confirmed DMD mutation; the FDA has removed the indication for non-ambulatory patients and is investigating risks of acute liver failure with serious outcomes.

Available evidence for Elevidys is mixed. Early phase studies demonstrated increased micro-dystrophin expression and suggested trends toward functional improvement in small cohorts, but the pivotal phase 3 randomized EMBARK trial failed to meet its prespecified primary functional endpoint (change in NSAA at 52 weeks), raising uncertainty about clinical benefit despite biologic effect on dystrophin expression.

Safety concerns have been reported, including instances of acute liver injury associated with delandistrogene that in some cases required treatment such as steroids and/or intravenous immunoglobulin; these events have contributed to ongoing safety review and regulatory scrutiny.

Defined Terms

Definitions

NSAA (North Star Ambulatory Assessment)A standardized functional scale for ambulatory children with Duchenne muscular dystrophy used to assess motor abilities, including item scores and times.

6MWT (Six-minute walk test)A measure of ambulatory function reported in meters over six minutes; used as a baseline functional measurement for coverage determinations.

Anti-AAVrh74 total binding antibody titerSerologic measure of antibodies against the AAVrh74 capsid; a titer <1:400 is required for coverage (patients with titers at or above 1:400 are excluded).

Numeric and Clinical Thresholds

Coverage thresholds

Age4-5 years

Anti-AAVrh74 total binding antibody titer<1:400 (threshold for eligibility; titers ≥1:400 are exclusionary)

Six-minute walk test (6MWT)>= 200 meters; baseline 6MWT must be documented within the past 3 months

Policy Changes

April 2026clarifiedLatest

Ad hoc review: policy reformatted; Medicare Advantage section and criteria hierarchy in the One Care and SCO section clarified; eligibility criteria moved to the Medicare Advantage section.

April 2026added

Prime Therapeutics information added for Commercial and Qualified Health Plan prior authorization management.

January 2026administrative

Ad hoc review: fixed formatting, updated prior authorization table, and added variation for One Care and SCO members.