CurrentCignaPolicy IP0137

Muscular Dystrophy - Amondys 45

Coverage policy governing prior authorization and medical necessity criteria for Amondys 45 (casimersen IV) for patients with Duchenne muscular dystrophy amenable to exon 45 skipping under Cigna-administered plans.

Policy Summary

PayerCigna

PolicyMuscular Dystrophy - Amondys 45

Policy CodePolicy IP0137

Change TypeRevised (title and dosing) + Clarifications

Effective DateThe policy effective date is in force until updated or retired.

Next Review Date

Key ActionObtain prior authorization and submit required documentation to support medical necessity for Amondys 45.

SourceLink

POLICY UPDATE CHANGES

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

Added documentation requirement language specifying acceptable documentation types.

Clarified wording of diagnostic confirmation to '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 skipping.'

6 monthsApproval duration

30 mg/kgApproved dosing

>=300 m6MWT minimum

>=50%FVC minimum

Policy Summary

PayerCigna

PolicyMuscular Dystrophy - Amondys 45

Policy CodePolicy IP0137

Change TypeRevised (title and dosing) + Clarifications

Effective DateThe policy effective date is in force until updated or retired.

Next Review Date

Key ActionObtain prior authorization and submit required documentation to support medical necessity for Amondys 45.

SourceLink

On This Page

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Coverage Criteria for Amondys 45 (casimersen)

FDA-Approved Indication - Duchenne Muscular Dystrophy

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

A or B: Either Initial Therapy (A) OR Currently Receiving Amondys 45 (B)

A. Initial Therapy: Approve for 6 months if ALL of the following are met

A.i: Less than 14 years of age at start of therapy<14 years

A.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 test confirming amenable mutation

A.iii: Able to walk a distance of at least 300 meters independently over 6 minutes>=300 meters

A.iv: Forced vital capacity is at least 50%>=50% FVC

A.v: Medication is prescribed by, or in consultation with, a neurologist, neuromuscular specialist, or Muscular Dystrophy Association clinicspecialist prescriber

B. Currently Receiving Amondys 45: Approve for 6 months if ALL of the following are met

B.i: The above criteria were met prior to initiation of Amondys 45

B.ii: Patient has experienced a beneficial clinical response, including the continued ability to walkevidence of benefit/continued ambulation

B.iii: Medication continues to be prescribed by, or in consultation with, a neurologist, neuromuscular specialist, or Muscular Dystrophy Association clinicspecialist prescriber

Amondys 45 (casimersen) is not medically necessary for indications other than the FDA‑approved Duchenne muscular dystrophy population described in this policy. The policy explicitly states that Amondys 45 for any other use is considered not medically necessary. In addition, concurrent administration with other exon‑skipping Duchenne agents is not supported by clinical evidence and is treated as a limitation on use under this policy.

Providers seeking coverage must follow the prior authorization requirements and submit the documentation required by the criteria (see provider actions). Approvals when criteria are met are issued for specified durations (typically 6 months), and claims that do not meet covered diagnosis, procedure, or documentation requirements will be denied as not covered.

Concurrent use of Amondys 45 with other exon‑skipping DMD agents is not supported by current clinical evidence and is therefore considered not medically necessary. The policy therefore does not authorize simultaneous treatment with multiple exon‑skipping therapies for DMD.

This exclusion applies regardless of prior or concurrent exposure to other exon‑skipping agents and should be considered when evaluating prior authorization requests for casimersen.

Coding and Test Thresholds

Considered Medically Necessary when criteria metHCPCSCovered

J1426

Injection, casimersen, 10 mg

inv-05: 6-Minute Walk Test threshold — minimum value for initiation

6-Minute Walk Test (initiation)>= 300 meters walked independently over 6 minutes

Use contextRequired for Initial Therapy (A.iii) to qualify for approval

Age linkageApplies when initiating therapy in patients <14 years of age per criteria A.i and A.iii

inv-06: Forced Vital Capacity threshold — minimum percent for initiation

Forced Vital Capacity (FVC) threshold>= 50%

Use contextRequired for Initial Therapy (A.iv) to qualify for approval

Provider Requirements and Prior Authorization

Prior Authorization

Prior authorization required — approvals issued for 6 months

Prior authorization is required for prescription benefit coverage of Amondys 45. Approvals are provided for 6 months when the applicable coverage criteria are met.

HCPCS J1426 is the listed code for casimersen (Injection, casimersen, 10 mg).
Approvals for both initial therapy and ongoing therapy are for 6 months per the criteria.

Step Therapy

Do not use concurrently with other exon‑skipping agents

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

Background on Amondys 45

Amondys 45 (casimersen) is an antisense oligonucleotide approved for the treatment of Duchenne muscular dystrophy in patients with a pathogenic or likely pathogenic DMD gene variant that is amenable to exon 45 skipping. Approval is under the FDA‑approved indication described in this policy, with dosing specified as 30 mg/kg once weekly administered as a 35–60 minute intravenous infusion. Continued coverage is contingent on meeting the policy criteria, which include genetic confirmation of an exon 45‑amenable mutation and demonstration of clinical benefit when applicable.

Definitions and Regulatory Context

inv-12: Accelerated approval — definition and implications (confirmatory trial requirement)

DefinitionFDA accelerated approval granted based on an increase in dystrophin as a surrogate endpoint

Implication 1Continued FDA approval may be contingent upon verification of clinical benefit in a confirmatory trial

Implication 2Prescribing information notes the need for confirmatory trial results to verify clinical benefit

inv-13: DMD exon 45 amenable mutation — definition of amenable to exon 45 skipping

DefinitionA pathogenic or likely pathogenic variant in the DMD gene for which exon 45 skipping would restore the reading frame (amenable to exon 45 skipping)

Documentation requiredGenetic testing confirming the DMD variant that is amenable to exon 45 skipping is required per criteria A.ii