CurrentMass General Brigham Health PlanPolicy 080

Medical Policy Lenmeldy (atidarsagene autotemcel)

Defines medical necessity criteria, exclusions, payer variations, and billing code information for infusion of Lenmeldy for treatment of MLD for Mass General Brigham Health Plan members across commercial, Medicare Advantage, MassHealth ACO, One Care, and SCO plans.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Policy Lenmeldy (atidarsagene autotemcel)

Policy CodePolicy 080

Change TypeAd hoc and annual updates (most recent: Jan 2026)

Effective DateOct 1, 2024

Next Review Date

Key ActionPrior authorization is required for Lenmeldy; submit requests per the payer variation (Prime Therapeutics for Commercial/QHP, MassHealth DUR for ACO, and prior auth applies to One Care and SCO).

SourceLink

POLICY UPDATE CHANGES

January 2026 ad hoc update: Updated prior authorization table and added variation for One Care and SCO members.

October 2025 annual update: Fixed code disclaimer, updated link to MassHealth Drug List table, fixed headings and typos, and updated code list.

April 2025 ad hoc update: MassHealth variation updated to include new prior authorization process.

March 2025: Summary of evidence added.

October 2024: Effective date established.

3Covered Indications (PSLI, PSEJ, ESEJ)

2Required diagnostic confirmations (ARSA activity + 24-hour urine sulfatide)

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Informational HCPCS code listed (J3391)

Coverage Summary

Subject: Lenmeldy (atidarsagene autotemcel) for metachromatic leukodystrophy (MLD). Payer: Mass General Brigham Health Plan. Policy number: 080. Effective date: 2024-10-01. Coverage stance: covered_with_criteria.

Scope summary: This policy defines medical necessity criteria, exclusions, payer variations, and billing code information for infusion of Lenmeldy for treatment of early-onset MLD across Mass General Brigham Health Plan lines of business (Commercial, Medicare Advantage, MassHealth ACO, One Care, and SCO). Criteria are based on trial inclusion criteria and regulatory approvals and require documentation of genotype, diagnostic testing, clinical status, transplant candidacy, and absence of disqualifying infections or organ impairment.

Supporting statistics (for reference only): • 3 covered indications (PSLI, PSEJ, ESEJ) • 1 required diagnostic confirmation set (ARSA activity + 24-hour urine sulfatide) • 1 informational HCPCS code listed.

Quick Facts

Policy Number080

Effective Date2024-10-01

Last Review2026-01-01

StatusCURRENT

Covered Indications (count)3

Informational code count1

Medically Necessary Coverage Criteria

Lenmeldy is considered medically necessary when ALL of the following criteria are met:

ALL of the following

Diagnosis (ONE of)
- PSLI
  - 2 null mutant ARSA alleles
  - Member is up to 30 months of age
  - Absence of neurological signs and symptoms of MLD except for abnormal reflexes or abnormalities on brain MRI and/or nerve conduction tests not associated with functional impairment (e.g., no tremor, no peripheral ataxia)

Provider Actions & Documentation Requirements

Prior Authorization

Prior authorization required

Prior authorization is required for Lenmeldy for the listed plans. Prior authorization for Commercial and Qualified Health Plan members is managed by Prime Therapeutics; Mass General Brigham ACO members submit to the MassHealth Drug Utilization Review Program. Recent updates added One Care and SCO variations to the prior authorization table and policy header.

Commercial
Mass General Brigham ACO
Medicare Advantage
One Care
SCO
Prime Therapeutics manages prior authorization for Commercial and Qualified Health Plan members
MassHealth Drug Utilization Review Program submission for Mass General Brigham ACO members
January 2026 update: added prior authorization applicability for One Care and SCO

Coding

Informational HCPCS/J-code for LenmeldyHCPCS

J3391

Injection, atidarsagene autotemcel, per treatment.

The procedure code listed (J3391) is provided for informational purposes only; inclusion of a code does not constitute or imply coverage or reimbursement.

See the policy header and variations for prior authorization details and the MassHealth Drug List reference for Mass General Brigham ACO members; prior authorization routing and submission processes were updated in January and April 2025 ad hoc updates.

Background & Evidence

Lenmeldy (atidarsagene autotemcel) is a lentiviral hematopoietic stem cell gene therapy indicated for early-onset forms of metachromatic leukodystrophy (MLD). The policy criteria are derived from inclusion criteria used in pivotal nonrandomized, open-label phase 1/2 trials (Sessa et al., Biffi et al., Fumagalli et al.) and from regulatory approvals and evidence summaries.

The trials demonstrated restoration of ARSA enzyme activity (reported increases to approximately 20–50% of normal activity in Fumagalli et al. 2022) and preservation of neurological function in a high proportion of treated patients, forming the evidence basis for the medical necessity criteria in this policy.

Key Evidence Metrics

ARSA enzyme activity achieved in trials20-50% of normal activity (Fumagalli et al. 2022)

Proportion with neurological function preservationOver 80% in treated patients (Fumagalli et al. 2022)

PSLI: Pre-symptomatic late infantile metachromatic leukodystrophy — defined in the policy as presence of 2 null mutant ARSA alleles, age up to 30 months, absence of neurological signs/symptoms except for limited findings (e.g., abnormal reflexes or MRI/nerve conduction abnormalities not causing functional impairment), and peripheral neuropathy by electroneurographic study.

Medicare Determinations

Document	Type/Reference
Medicare Benefit Policy Manual Chapter 15: Covered Medical and Other Health Services	NCD

Revision History

2024-10policy_effective

Policy became effective October 1, 2024.

2025-03evidence_added

Summary of evidence from pivotal trials and safety data added.

2025-04ad_hoc_update

MassHealth variation updated to include new prior authorization process.

Policy Summary

PayerMass General Brigham Health Plan

PolicyMedical Policy Lenmeldy (atidarsagene autotemcel)

Policy CodePolicy 080

Change TypeAd hoc and annual updates (most recent: Jan 2026)

Effective DateOct 1, 2024

Next Review Date

SourceLink

On This Page

Peripheral neuropathy as determined by electroneurographic study

PSEJ

1 null and 1 R mutant ARSA allele(s)
Member is less than 7 years of age
Absence of neurological signs and symptoms of MLD or physical examination findings limited to abnormal reflexes and/or clonus except for abnormal reflexes or abnormalities on brain MRI and/or nerve conduction tests not associated with functional impairment (e.g., no tremor, no peripheral ataxia)
Peripheral neuropathy as determined by electroneurographic study

ESEJ

1 null and 1 R mutant ARSA allele(s)
Disease onset after 30 months and before 7 years of age
Member is less than 18 years of age
IQ is at least 85 on age-appropriate neurodevelopmental testing
Gross Motor Function Classification in metachromatic leukodystrophy (GMFC-MLD) level 0 w/ ataxia OR GMFC-MLD level 1

ALL of the following

Arylsulfatase A (ARSA) enzyme activity below the normal range
A 24-hour urine collection showing elevated sulfatide levels

Absence of

Clinically significant and active bacterial, fungal, parasitic, severe concomitant disease or viral infection including Hepatitis B, Hepatitis C, or HIV
Hepatic and/or renal impairment

Member is a candidate for allogeneic hematopoietic stem cell transplantation but there is no available matched donor

Member has not received a prior allogeneic stem cell transplant (or if they have, there is no evidence of residual donor cells present)

Member has not received Lenmeldy or any other gene therapy previously

Medication is prescribed by or in consultation with a physician who specializes in the treatment of MLD

Documentation Required

Documentation of diagnostic confirmation

Provider must document diagnostic confirmation to support medical necessity.

Arylsulfatase A (ARSA) enzyme activity below the normal range
A 24-hour urine collection showing elevated sulfatide levels

Documentation Required

Genetic and clinical details

Provider must document genetic and clinical details relevant to MLD subtype and eligibility.

ARSA genotype (null/null or null/R as applicable for PSLI, PSEJ, ESEJ)
Age at diagnosis or disease onset (criteria vary by subtype: up to 30 months, <7 years, <18 years)
IQ testing results when applicable (IQ ≥ 85 for ESEJ)
Gross Motor Function Classification in MLD (GMFC-MLD) level
Electroneurographic evidence of peripheral neuropathy
Absence of clinically significant active infections (including Hepatitis B, Hepatitis C, HIV) and absence of hepatic and/or renal impairment

Documentation Required

Transplant candidacy and prior transplant status

Provider must document transplant candidacy and prior transplant status to support eligibility.

Member is a candidate for allogeneic hematopoietic stem cell transplantation but there is no available matched donor
Member has not received a prior allogeneic stem cell transplant (or if they have, there is no evidence of residual donor cells present)

PSEJ: Pre-symptomatic early juvenile metachromatic leukodystrophy — defined as 1 null and 1 R mutant ARSA allele, age 7 years, absence of neurological signs/symptoms or findings limited to abnormal reflexes/clonus without functional impairment, and peripheral neuropathy by electroneurographic study.

ESEJ: Early symptomatic early juvenile metachromatic leukodystrophy — defined as 1 null and 1 R mutant ARSA allele, disease onset between >30 months and <7 years, member <18 years of age, IQ ≥ 85 on age-appropriate testing, and GMFC-MLD level 0 with ataxia or level 1.

2025-10annual_update

Annual update: fixed code disclaimer, updated link to MassHealth Drug List table, corrected headings and typos, and updated code list.

2026-01ad_hoc_updateLatest

January 2026 ad hoc update: updated prior authorization table and added variation for One Care and SCO members.