CurrentCignaPolicy IP0137

Amondys 45 (casimersen) coverage

Defines Cigna's prior authorization, coverage criteria, dosing, and documentation requirements for Amondys 45 (casimersen) for treatment of Duchenne muscular dystrophy in patients with DMD gene mutations amenable to exon 45 skipping.

Policy Summary

PayerCigna

PolicyAmondys 45 (casimersen) coverage

Policy CodePolicy IP0137

Change TypeTitle and dosing addeddiagnostic wording clarifieddocumentation examples added

Effective DateJun 1, 2025

Next Review DateN/A

Key ActionObtain prior authorization and submit documentation confirming DMD with a pathogenic or likely pathogenic DMD gene variant amenable to exon 45 skipping.

SourceLink

POLICY UPDATE CHANGES

Updated policy title; previously it was Casimersen and added dosing to the policy.

Clarified wording for confirmation of DMD diagnosis to 'Documentation is provided that the patient has a diagnosis... confirmed by a pathogenic or likely pathogenic variant in the DMD gene that is amenable to exon 45 skipping.'

Added a documentation requirement specifying examples of acceptable documentation (chart notes, labs, test results, claims records).

6 monthsapproval duration

30 mg/kg weeklyapproved dosing

>=300 m6MWT requirement

>=50%

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Coverage Criteria for Amondys 45 (casimersen)

FDA-Approved Indication and Dosing

Approve for the duration noted if the patient meets ONE of the following (A or B):

A: Initial Therapy

i: Less than 14 years of age at start of therapy<14 years
ii: Documentation is provided that the patient has a diagnosis of Duchenne muscular dystrophy which is confirmed by a pathogenic or likely pathogenic variant in the DMD gene that is amenable to exon 45 skippinggenetic confirmation
iii: Able to walk a distance of at least 300 meters independently over 6 minutes>=300 meters
6-Minute Walk Test
iv: Forced vital capacity is at least 50%>=50% FVC
v: Medication is prescribed by, or in consultation with, a neurologist, neuromuscular specialist, or by a Muscular Dystrophy Association clinicspecialist involvement

B: Currently Receiving Amondys 45

i: The above criteria were met prior to initiation of Amondys 45prior documented eligibility
ii: Patient has experienced a beneficial clinical response, including the continued ability to walkclinical benefit
iii: Medication continues to be prescribed by, or in consultation with, a neurologist, neuromuscular specialist, or by a Muscular Dystrophy Association clinicspecialist involvement

Dosing: Approve 30 milligrams per kilogram administered once weekly as a 35 to 60-minute intravenous infusion30 mg/kg weekly

Infusion duration 35-60 minutes

Concurrent use of Amondys 45 with other exon-skipping agents for Duchenne muscular dystrophy is not supported by available clinical evidence. The policy therefore does not authorize simultaneous treatment with more than one exon-skipping DMD agent.

Use of Amondys 45 for any indication other than Duchenne muscular dystrophy with a pathogenic or likely pathogenic DMD gene variant amenable to exon 45 skipping is considered not medically necessary and is not covered under this policy.

Concurrent administration of exon-skipping therapies is explicitly addressed: there is currently no clinical evidence to support the concurrent use of exon-skipping DMD agents. Such combined use is therefore considered unsupported and not covered.

Amondys 45 is approved for the treatment of Duchenne muscular dystrophy only when the patient has a DMD gene variant amenable to exon 45 skipping. Use of Amondys 45 for other indications or patient populations is considered not medically necessary and will not be authorized.

Coding, Tests, and Clinical Thresholds

Considered Medically Necessary when criteria metHCPCSCovered

J1426

Injection, casimersen, 10 mg

inv-07: 6-Minute Walk Test threshold

6-Minute Walk Test (6MWT) requirementPatient must be able to walk at least 300 meters independently over 6 minutes (>= 300 meters).

PurposeUsed as an initiation criterion for initial therapy authorization for Amondys 45 (approvals granted for 6 months when met).

MeasurementStandard 6-minute walk test distance measured in meters; report documented result in the medical record at initiation.

inv-08: Forced vital capacity threshold

Forced vital capacity (FVC) requirementForced vital capacity must be at least 50% (>= 50%).

PurposeRequired respiratory function threshold for initiation of Amondys 45 therapy (part of initial 6-month approval criteria).

Provider Requirements and Prior Authorization

Prior Authorization

Prior Authorization Required

Prior authorization is required for prescription benefit coverage of Amondys 45. All approvals are provided for the duration noted in the policy. Because of the specialized skills required for evaluation and diagnosis, approval requires Amondys 45 to be prescribed by or in consultation with a physician who specializes in the condition being treated.

Approvals provided for specified durations (see policy criteria).
Prescriber requirement: neurologist, neuromuscular specialist, or Muscular Dystrophy Association clinic.

Billing Rule

Concurrent Exon‑Skipping Agents Not Supported

Concurrent use of Amondys 45 with other exon‑skipping Duchenne muscular dystrophy agents is not supported by clinical evidence and is considered not medically necessary.

Background on Amondys 45

Amondys 45 (casimersen) is an antisense oligonucleotide granted accelerated approval to increase dystrophin production in skeletal muscle for patients with Duchenne muscular dystrophy whose DMD gene mutation is amenable to exon 45 skipping. Continued approval may depend on verification of clinical benefit in confirmatory trials. The approved dosing in this policy is 30 mg/kg once weekly administered as an intravenous infusion over 35 to 60 minutes, with authorizations provided for specified durations when the coverage criteria are met.

Key Definitions

inv-15: Amenable to exon 45 skipping — definition and required genetic confirmation

DefinitionA DMD gene pathogenic or likely pathogenic variant that can be targeted by exon 45 skipping therapy (i.e., a mutation amenable to exon 45 skipping).

Required confirmationDocumentation must show the patient has Duchenne muscular dystrophy confirmed by a pathogenic or likely pathogenic variant in the DMD gene that is amenable to exon 45 skipping.

Use restrictionAmondys 45 is indicated only for patients with DMD and a mutation amenable to exon 45 skipping; use for other indications is not medically necessary.

Initial Therapy Authorization Criteria

Initial Therapy

Initial therapy authorization:

initial_criteria: Patient <14 years, genetic confirmation of DMD amenable to exon 45 skipping, 6MWT >=300 m, FVC >=50%, prescribed by or in consultation with specified specialistsmultiple

Approve for 6 months

Continuation / Renewal Criteria

Continuation Therapy

Renewal (patients currently receiving Amondys 45):

renewal_criteria: Approve for 6 months if the patient met initial criteria prior to initiation, has experienced a beneficial clinical response including continued ability to walk, and continues to be prescribed by or in consultation with an appropriate specialistclinical benefit

Step Therapy and Combination Rules

Step	Requirement
1	Do not combine with other exon‑skipping DMD agents; concurrent use is unsupported by clinical evidence and is considered not medically necessary.

Administration and Site-of-Care

Note

Administer IV infusion at clinically appropriate site

Amondys 45 is administered as an intravenous infusion; dosing and site of care should be reasonable and clinically appropriate.

Dose: 30 mg/kg once weekly as a 35–60 minute IV infusion.
Select infusion center or other site of care based on clinical appropriateness and supporting evidence.