CurrentMass General Brigham Health PlanPolicy N/A

Exondys 51 (eteplirsen) — Prior authorization coverage criteria for Duchenne muscular dystrophy

Defines prior authorization medical-benefit coverage and continuation criteria for Exondys 51 for members with Duchenne muscular dystrophy who have DMD gene mutations amenable to exon 51 skipping; applies to MassHealth members under the plan.

Policy Summary

PayerMass General Brigham Health Plan (MassHealth)

PolicyExondys 51 (eteplirsen) — Coverage criteria (medical benefit)

Policy CodePolicy N/A

Change TypeMaterial coverage updates

Effective DateJun 1, 2025

Next Review DateN/A

Key ActionSubmit prior authorization with documentation of confirmed DMD mutation amenable to exon 51 skipping, baseline and interim 6MWT and timed function tests, corticosteroid history, dosing, and statement that no prior gene therapy was received.

SourceLink

POLICY UPDATE CHANGES

Extended approval duration to 6 months.

Added criterion that member must not have used any gene therapy prior to therapy with Exondys 51.

Policy updated to better reflect agents with prior authorization on the medical benefit and formatting and references updated.

6 monthsApproval length

>=200 mMinimum 6MWT

30 mg/kg wklyIV dosing

>=6 months

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Coverage Criteria for Exondys 51 (eteplirsen)

Initial Therapy Criteria

Covered when ALL of the following are met

Initial Therapy: 1. Diagnosis of Duchenne Muscular Dystrophy; 2. Documentation of a confirmed out-of-frame deletion in the DMD that is amenable to exon 51 skipping; 3. The prescribing physician is a neuromuscular neurologist or consult notes from a neuromuscular neurology office are provided; 4. The member is ambulatory as defined by a current six-minute walk test (6MWT) of ≥ 200 meters (test must have been observed or completed by the treating provider, or ordered by the treating provider and completed by a qualified medical practitioner); 5. Dosing is appropriate: 30 mg/kg intravenously every week; 6. Member has received a corticosteroid for at least 6 months prior and will continue to use a corticosteroid in combination with the requested agent OR has a demonstrated contraindication to corticosteroids; 7. Member has baseline measurements for ALL of the following timed function tests documented in the medical record (tests must have been observed or completed by the treating provider, or ordered by the treating provider and completed by a qualified medical practitioner): (a) timed ten-meter walk/run (seconds); (b) timed floor (supine) to stand (seconds); (c) timed four-step descend (seconds); (d) timed four-step climb (seconds); (e) timed sit to stand (seconds); 8. Member has not previously received treatment with a gene therapy for DMD.

All items required.

Continuation Therapy Criteria

Reauthorization covered when ALL of the following are met

Continuation Therapy: 1. The member remains ambulatory as defined by a current six-minute walk test (6MWT) of ≥ 200 meters (test must have been observed or completed by the treating provider, or ordered by the treating provider and completed by a qualified medical practitioner); 2. The member has a stable or improving pattern of 6MWTs with pretreatment baseline and all interim results provided (all previous 6MWT results must be included); 3. Dosing remains appropriate (30 mg/kg intravenously every week); 4. The member continues to utilize corticosteroid in combination with the requested agent OR has a demonstrated contraindication to corticosteroids; 5. Member demonstrates a stable or improving pattern on at least TWO of the five timed function tests with all results and dates provided (tests must have been observed or completed by the treating provider, or ordered by the treating provider and completed by a qualified medical practitioner): (a) timed ten-meter walk/run; (b) timed floor (supine) to stand; (c) timed four-step descend; (d) timed four-step climb; (e) timed sit to stand; 6. Prior to therapy with Exondys 51, member has not previously received treatment with a gene therapy for DMD.

All items required. Approvals may be granted for up to 6 months per policy change.

Use of Exondys 51 is excluded for members who have previously received a gene therapy for Duchenne muscular dystrophy (DMD). No other explicit exclusions are listed in the policy.

Treatment requests will not be authorized when required baseline or follow-up objective measures are missing. Required documentation includes genetic confirmation of an out‑of‑frame deletion in the DMD gene that is amenable to exon 51 skipping, a baseline six‑minute walk test (6MWT) and all baseline timed function tests, and, for reauthorization, interim 6MWT and timed function test results demonstrating stability or improvement. Operationally, tests must be observed or completed by the treating provider, or ordered by the treating provider and completed by a qualified medical practitioner; absence of these documented results is a trigger for denial.

Coding and Objective Measures

Neutral — codes not specifiedmixed

NDC/HCPCS not specified

No specific billing codes listed in document

Six-minute walk test (6MWT) threshold

Required 6MWT thresholdMember must have a current six-minute walk test (6MWT) distance of >= 200 meters (test observed/completed by treating provider or ordered and completed by a qualified practitioner)

When appliedRequired for both initial authorization and reauthorization (ambulatory definition used in coverage criteria)

DocumentationProvide the actual 6MWT result with date and indication that the test was observed or completed by the treating provider or a qualified medical practitioner

Consequence of not meeting thresholdRequests with 6MWT < 200 meters do not meet the ambulatory requirement and may be denied

Provider Actions, Documentation, and Prior Authorization

Prior Authorization

Prior authorization required (medical benefit)

Prior authorization is required on the medical benefit for Exondys 51; requests are reviewed on a case‑by‑case basis and must meet the coverage criteria in the policy.

Step Therapy

No step therapy required

No step therapy requirements apply to Exondys 51 under this policy.

Documentation Required

Documentation required for prior authorization

Provide medical record documentation with the prior authorization request including: diagnosis of Duchenne muscular dystrophy; genetic testing confirming a confirmed out‑of‑frame deletion in the DMD gene that is amenable to exon 51 skipping; baseline and all interim six‑minute walk test (6MWT) results (test observed/completed by treating provider or qualified practitioner); baseline measurements for all five timed function tests (timed ten‑meter walk/run, timed floor to stand, timed four‑step descend, timed four‑step climb, timed sit to stand); prescribing clinician specialty or neuromuscular neurology consult notes; documentation of at least 6 months of prior corticosteroid use or a documented contraindication; documentation that the member has not previously received a gene therapy for DMD; and documentation of the prescribed dosing (30 mg/kg IV weekly).

Background

Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder caused by mutations in the DMD gene. Exondys 51 (eteplirsen) is an antisense oligonucleotide therapy indicated for patients with DMD whose mutations are amenable to exon 51 skipping. Per the policy, initiation requires a confirmed out‑of‑frame deletion amenable to exon 51 skipping, provider specialty information, documentation of ambulation with a 6MWT ≥ 200 meters, baseline timed function tests, appropriate intravenous dosing of 30 mg/kg weekly, and prior corticosteroid use or documented contraindication. Reauthorization requires continued ambulation (current 6MWT ≥ 200 meters) and demonstrated stable or improving function on 6MWT and timed function tests.

Definitions

Amenable to exon 51 skipping

DefinitionA confirmed mutation of the DMD gene (out-of-frame deletion) that molecularly qualifies for exon 51 skipping

Required genetic documentationMust provide genetic test results documenting a confirmed out‑of‑frame deletion in the DMD gene that is amenable to exon 51 skipping

Context in policyDocumentation of an exon 51‑amenable mutation is listed as a required criterion for initial authorization

Source of confirmationGenetic testing reports in the medical record that explicitly state the mutation is amenable to exon 51 skipping

Ambulatory (policy definition)

Policy definition of ambulatoryAmbulatory is defined as a current six‑minute walk test (6MWT) distance of >= 200 meters, observed or completed by the treating provider or ordered and completed by a qualified medical practitioner