CurrentUnitedHealthcarePolicy CSNJ2026D0105L

Amondys 45 (Casimersen) (for New Jersey Only)

This UnitedHealthcare Medical Benefit Drug Policy governs coverage criteria for Amondys 45 (casimersen) for treatment of Duchenne muscular dystrophy in New Jersey members and defines initial and continuation authorization requirements.

Policy Summary

PayerUnitedHealthcare

PolicyAmondys 45 (Casimersen) (for New Jersey Only)

Policy CodePolicy CSNJ2026D0105L

Change TypeRevised coverage criteria

Effective DateMay 1, 2026

Next Review Date

Key ActionObtain prior authorization and submit medical records confirming the DMD gene mutation is amenable to exon 45 skipping and baseline functional status; initial and reauthorization approvals are up to 12 months when criteria are met.

SourceLink

POLICY UPDATE CHANGES

Revised coverage criteria; added criterion requiring Amondys 45 will not be used concomitantly with Duvyzat (givinostat).

12 monthsmaximum initial authorization duration

12 monthsmaximum reauthorization duration

J1426HCPCS code for casimersen (10 mg)

G71.01Diagnosis code listed

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Initial Therapy

Covered when ALL of the following are met:

Initial Therapy: Diagnosis of Duchenne muscular dystrophy by, or in consultation with, a neurologist with expertise in the diagnosis of DMD; submission of medical records (e.g., chart notes, laboratory values) confirming the mutation of the DMD gene is amenable to exon 45 skipping; submission of medical records that provide baseline status of the patient prior to starting therapy (e.g., confirming the patient is walking without needing an assistive device such as a cane, walker, wheelchair, etc.); dosing is in accordance with the United States Food and Drug Administration approved labeling; and prescribed by, or in consultation with, a neurologist with expertise in the treatment of DMD; initial authorization will be for no more than 12 months.

Prior gene therapy status: One of the following: Patient has not previously received gene therapy (e.g., Elevidys [delandistrogene moxparvovec-rokl]) for the treatment of DMD; OR patient has previously received gene therapy for DMD and submission of medical records documents a clinically meaningful functional decline (e.g., loss of a motor milestone) since receiving gene replacement therapy.

This is an OR branch within Initial Therapy criteria.

Concomitant therapy restriction: Amondys 45 will not be used concomitantly with any of the following: Duvyzat (givinostat) or other exon skipping therapies for DMD (e.g., Exondys 51 [eteplirsen], Viltepso [viltolarsen], Vyondys 53 [golodirsen]).

Explicit prohibition on concomitant use.

Continuation Therapy

Covered for continuation when ALL of the following are met:

Continuation Therapy: Submission of medical records (e.g., chart notes) confirming that the patient is receiving clinical benefit (e.g., walking without needing an assistive device such as a cane, walker, wheelchair, etc.); dosing is in accordance with the United States Food and Drug Administration approved labeling; prescribed by, or in consultation with, a neurologist with expertise in the treatment of DMD; reauthorization will be for no more than 12 months.

Explicit prohibition on concomitant use.

Unproven / Not Medically Necessary

Unproven Indications: Amondys 45 is unproven and not medically necessary for the treatment of other forms of muscular dystrophy (e.g., Becker muscular dystrophy) or for Duchenne muscular dystrophy that is not amenable to exon 45 skipping.

Amondys 45 (casimersen) is indicated and covered only for members with Duchenne muscular dystrophy (DMD) whose genetic mutation is amenable to exon 45 skipping. Treatment of other forms of muscular dystrophy (for example, Becker muscular dystrophy) is explicitly excluded from coverage. The clinical evidence and regulatory rationale for casimersen apply to exon 45–amenable DMD; there are no supporting data for its use in other dystrophies.

Use of Amondys 45 for diagnoses outside of exon 45–amenable DMD is considered unproven and not medically necessary. Clinical trials and available data did not evaluate casimersen in DMD not amenable to exon 45 skipping or in other muscular dystrophies such as Becker, and therefore these indications are not supported for coverage.

Provider Actions / Authorization Requirements

Prior Authorization

Prior Authorization Required

Prior authorization is required before initiating therapy with Amondys 45. Initial and reauthorization approvals are granted for a maximum duration; see applicable HCPCS for billing reference.

Prior authorization is required.
Initial authorization: up to 12 months.
Reauthorization: up to 12 months.
Billing reference: HCPCS J1426.

Denial Risk

Concomitant Therapy Restriction

Amondys 45 must not be used concomitantly with certain therapies. Requests may be denied if concomitant use with disallowed agents is documented.

Do not prescribe Amondys 45 with Duvyzat (givinostat).
Do not prescribe Amondys 45 with other exon skipping therapies for DMD (e.g., Exondys 51 - eteplirsen, Viltepso - viltolarsen, Vyondys 53 - golodirsen).

Documentation Required

Required Documentation

Submit required documentation with the prior authorization request. Incomplete documentation may result in delayed processing or denial.

Medical records and chart notes supporting diagnosis of Duchenne muscular dystrophy and specialist involvement (neurologist with DMD expertise).
Genetic testing report confirming a DMD gene mutation amenable to exon 45 skipping.
Baseline functional status prior to starting therapy (e.g., documentation that the patient is ambulatory without an assistive device).
For patients previously treated with gene therapy (e.g., Elevidys), documentation of a clinically meaningful functional decline since gene therapy if seeking initial therapy after prior gene replacement.
Ongoing clinical documentation of benefit for continuation requests (e.g., continued ambulation without assistive device).
Relevant laboratory values and other chart notes as applicable.

Denial Risk

Triggers for Denial

The following conditions may lead to denial of the authorization request if not satisfied or if contraindicated.

No documentation confirming the DMD mutation is amenable to exon 45 skipping.
Missing baseline functional measures prior to initiation (e.g., lack of documentation that the patient was ambulatory without an assistive device).
Documentation of concomitant use of disallowed therapies (e.g., Duvyzat/givinostat or other exon skipping agents).
Lack of specialist involvement (no documentation of prescription by or consultation with a neurologist experienced in DMD).

Definitions

Amenable to exon 45 skipping

DefinitionA confirmed mutation of the DMD (dystrophin) gene located in the exon 45 region that permits restoration of dystrophin production via exon 45 skipping induced by casimersen.

MechanismCasimersen (Amondys 45) is an antisense oligonucleotide that binds to dystrophin pre-mRNA at exon 45 and induces splicing (exon 45 skipping) to allow production of a truncated but functional dystrophin protein.

Regulatory noteFDA indication: Amondys 45 is approved for DMD patients with a confirmed mutation amenable to exon 45 skipping; approval granted under accelerated approval based on increased dystrophin in skeletal muscle.

Clinical implicationOnly patients with genetic test results confirming an exon 45–amenable mutation should be considered for therapy; DMD not amenable to exon 45 skipping is excluded from coverage.

ExclusionsUse for other forms of muscular dystrophy (e.g., Becker) or DMD mutations not amenable to exon 45 skipping is considered unproven and not medically necessary.

Background

Duchenne muscular dystrophy (DMD) is an X‑linked, progressive neuromuscular disorder characterized by loss of dystrophin leading to progressive skeletal and cardiac muscle weakness, most often affecting males. Casimersen is an antisense oligonucleotide designed to induce skipping of exon 45 in the DMD gene, producing a shortened but functional dystrophin protein in patients with mutations amenable to exon 45 skipping. Clinical trial data demonstrated increases in exon 45 skipping and small but statistically significant increases in dystrophin production in treated patients; however, casimersen has not been studied in patients whose DMD mutations are not amenable to exon 45 skipping or in other forms of muscular dystrophy (e.g., Becker muscular dystrophy).

OpenPayer

Amondys 45 (Casimersen) (for New Jersey Only)

Coverage Criteria for Amondys 45 (casimersen)

Coding

Provider Actions / Authorization Requirements

Definitions

Background

Revision History