CurrentUnitedHealthcarePolicy CS2026D0105N

Amondys 45 (Casimersen) — Medical Benefit Drug Policy (Community Plan)

Defines UnitedHealthcare Medical Benefit Drug Policy coverage criteria for Amondys 45 (casimersen) for treatment of Duchenne muscular dystrophy in patients with DMD gene mutations amenable to exon 45 skipping; applies to Community Plan membership except where state-specific rules override.

Policy Summary

PayerUnitedHealthcare

PolicyAmondys 45 (Casimersen) — Medical Benefit Drug Policy (Community Plan)

Policy CodePolicy CS2026D0105N

Key ActionRequest prior authorization and submit medical records confirming DMD diagnosis, exon 45 amenable mutation, ambulatory/functional measures, and DMD-expert neurologist involvement.

Change TypeRevised — added concomitant-therapy exclusion

Effective DateMay 1, 2026

Next Review DateN/A

SourceLink

POLICY UPDATE CHANGES

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

Updated References section to reflect the most current information.

≤12 moinitial coverage

≤12 mocontinuation coverage

J1426billing code

≥300 m6MWT threshold

Related Billing Codes

HCPCS-J1426-CASIMERSEN-INJECTION-10MG

HCPCS J1426: Injection, casimersen, 10 mg

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Coverage criteria for Amondys 45 (casimersen)

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 DMD

Genetic confirmation: Submission of medical records confirming the mutation of the DMD gene is amenable to exon 45 skipping

e.g., chart notes, laboratory values

Ambulatory function (option group)

6MWT option: Submission of medical records confirming 6-Minute Walk Test (6MWT) >= 300 meters while walking independently (without side-by-side assist, cane, walker, wheelchair, etc.) prior to initiating Amondys 45>= 300 meters
walking independently (no assistive device)
Alternate ambulatory option: Submission of medical records confirming the patient is ambulatory without needing an assistive device AND one of: NSAA > 17 OR Time to Rise (TTR) < 7 secondsNSAA > 17; TTR < 7 s
ambulatory without assistive device

Gene therapy status: Either patient has not previously received gene therapy for DMD OR if previously received gene therapy, submission of records documenting clinically meaningful functional decline (e.g., loss of muscle strength/motor ability or loss of a motor milestone) since gene replacement therapy

e.g., Elevidys (delandistrogene moxparvovec-rokl)

Concomitant therapy exclusion: Amondys 45 will not be used concomitantly with Duvyzat (givinostat) or other exon skipping therapies for DMD (e.g., eteplirsen, viltolarsen, golodirsen)

Prescribing and dosing: Prescribed by, or in consultation with, a neurologist with expertise in the treatment of DMD and dosing is in accordance with FDA approved labeling

Initial authorization up to 12 months

Continuation Therapy

Covered for continuation when ALL of the following are met

Ambulatory status: Submission of medical records confirming the patient is ambulatory without needing an assistive device (e.g., without side-by-side assist, cane, walker, wheelchair, etc.)

Concomitant therapy exclusion: Amondys 45 will not be used concomitantly with Duvyzat (givinostat) or other exon skipping therapies for DMD (e.g., eteplirsen, viltolarsen, golodirsen)

Prescribing and dosing: Prescribed by, or in consultation with, a neurologist with expertise in the treatment of DMD and dosing is in accordance with FDA approved labeling

Reauthorization up to 12 months

Use of Amondys 45 (casimersen) for other forms of muscular dystrophy such as Becker muscular dystrophy is considered unproven and not medically necessary.

Amondys 45 is not considered medically necessary for indications outside Duchenne muscular dystrophy; treatment of other dystrophies (for example, Becker muscular dystrophy) is unproven and not medically necessary.

Provider requirements and actions

Prior Authorization

Prior Authorization Required

Prior authorization is required for Amondys 45 (casimersen). Submit medical records confirming the diagnosis of Duchenne muscular dystrophy (DMD) by or in consultation with a neurologist experienced in DMD, documentation that the patient has an exon 45–amenable DMD gene mutation, and evidence that ambulatory criteria are met. Initial authorizations are limited to no more than 12 months; reauthorization requests must include updated documentation of continued ambulatory status and clinical response.

Affected product: Amondys 45 (casimersen)
Initial authorization: up to 12 months
Reauthorization: up to 12 months with required documentation

Documentation Required

Required Documentation

Submit complete medical records (chart notes, lab values, genetic testing) confirming DMD diagnosis and exon 45 amenable mutation, documentation of baseline ambulatory function (6MWT ≥ 300 meters OR ambulatory without assistive device plus NSAA > 17 or TTR < 7 seconds), prior gene therapy status and, if applicable, documentation of clinically meaningful decline after gene therapy. Include prescribing clinician name and documentation of consultation with a DMD‑experienced neurologist when applicable.

Genetic testing confirming exon 45 amenable mutation
Baseline functional measures: 6MWT, NSAA, or TTR as applicable
Documentation of ambulatory status (no assistive device)
Records regarding prior gene therapy and evidence of decline if prior gene therapy received
Prescribing clinician and consultation notes with DMD‑experienced neurologist

Denial Risk

Triggers for Denial

Denial may be issued if the member is non‑ambulatory, the dosing regimen does not follow FDA‑approved labeling, Amondys 45 is requested for concomitant use with prohibited therapies, or required documentation is incomplete/missing.

Non‑ambulatory status (e.g., requires wheelchair for ambulation) — denial trigger
Dosing inconsistent with FDA labeling — denial trigger
Concomitant use with any of the following: Duvyzat (givinostat) or other exon skipping therapies for DMD (Exondys 51, Viltepso, Vyondys 53) — denial trigger
Incomplete or missing medical records to support diagnosis, exon 45 amenability, or ambulatory criteria — denial trigger
Prior gene therapy without documentation of clinically meaningful functional decline (when applicable) — denial trigger

Definitions and measures

inv-13: Amenable to exon 45 skipping — definition of amenable mutation for casimersen

DefinitionA confirmed mutation of the DMD gene that can be targeted by casimersen resulting in exon 45 skipping and increased dystrophin production

Clinical implicationCasimersen is indicated only for patients with mutations amenable to exon 45 skipping; all trial casimersen recipients showed exon 45 skipping (100% response rate)

Testing requirementSubmission of medical records confirming the mutation is amenable to exon 45 skipping is required for coverage

inv-14: 6-Minute Walk Test (6MWT) — definition and how it is used in eligibility/criteria

Definition and purposeThe 6-Minute Walk Test (6MWT) is a measure of ambulatory function used in trial eligibility and policy criteria to assess walking endurance and baseline function

Policy use for eligibilityFor initial therapy, submission of medical records showing 6MWT ≥ 300 meters while walking independently satisfies one ambulatory-function pathway for coverage

Alternate roleESSENCE trial enrollment used mean 6MWT ≥ 300 m and ≤ 450 m to define ambulatory participants, providing context for clinical applicability

OpenPayer

Amondys 45 (Casimersen) — Medical Benefit Drug Policy (Community Plan)

Related Billing Codes

Coverage criteria for Amondys 45 (casimersen)

Billing and coding

Provider requirements and actions

Definitions and measures

Background