Aldurazyme (laronidase) — Enzyme Replacement Therapy for MPS I
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This policy governs prior authorization and medical necessity criteria for coverage of Aldurazyme (laronidase) for treatment of Mucopolysaccharidosis type I (MPS I) for Aspirus Medicare plans and applies to providers prescribing or requesting authorization.
No material clinical or coverage changes in this revision.
Coverage Criteria for Aldurazyme (laronidase)
Initial Approval Criteria (FDA-Approved Indication)
Covered when ALL of the following are met
Approval duration: 1 year if criteria met.
Coverage is not recommended for circumstances that are not listed in the Recommended Authorization Criteria. Requests for Aldurazyme outside the criteria described in this policy may be denied; the criteria will be updated as new published data become available.
Confirmation of MPS I diagnosis via molecular genetic testing of IDUA
This molecular finding is accepted as an equivalent diagnostic criterion to deficient enzyme activity.
Provider Actions and Authorization Requirements
Prior authorization recommended; approve 1 year if criteria and dosing met
Prior authorization is recommended for medical benefit coverage of Aldurazyme; approve for 1 year when the patient meets the policy criteria and dosing limits. Approvals may be extended if the patient continues to meet criteria; requests for doses outside the documented dosing will be considered case-by-case by a clinician.
- Approval duration: 1 year when criteria met; extended approvals allowed if criteria continue to be met.
- Dose requests outside established dosing (see dosing limit block) require case-by-case clinical review.
Relation to HSCT: HSCT indicated for severe early disease; Aldurazyme appropriate in specific pre/post-HSCT scenarios
HSCT is an indicated therapy for severe forms of MPS I in children <2 years who are cognitively intact. Aldurazyme is appropriate in certain pre- or post-HSCT contexts — e.g., for children <2 years who are cognitively intact with severe physical disease prior to HSCT or for children who have already experienced cognitive decline — and is recommended in older patients regardless of cognitive status.
- HSCT preserves intellectual development and is indicated for severe MPS I in children <2 years who are cognitively intact.
- Aldurazyme does not cross the blood–brain barrier and may be used pre- or post-HSCT in specified clinical scenarios.
Required diagnostic documentation and specialist prescriber
Documentation must demonstrate the diagnosis by either deficient α-L-iduronidase enzyme activity in leukocytes, fibroblasts, plasma, or serum OR by molecular genetic testing showing biallelic pathogenic or likely pathogenic IDUA variants; additionally, include that Aldurazyme is prescribed by or in consultation with an appropriate specialist.
- Acceptable diagnostic evidence: (a) enzyme assay showing deficient α-L-iduronidase activity in leukocytes, fibroblasts, plasma, or serum; OR (b) molecular genetic testing demonstrating biallelic pathogenic/likely pathogenic IDUA variants.
- Prescriber requirement: must be prescribed by or in consultation with a geneticist, endocrinologist, metabolic disorder sub-specialist, or physician who treats lysosomal storage disorders.
Non-listed indications may be denied
Coverage is not recommended for circumstances not listed in the Recommended Authorization Criteria; requests outside the listed criteria may be denied and criteria will be updated as new data become available.
- Requests for indications or clinical scenarios not specified in the policy’s Recommended Authorization Criteria are not recommended for approval.
Specialist prescriber required
Aldurazyme must be prescribed by or in consultation with a geneticist, endocrinologist, metabolic disorder sub-specialist, or other physician who specializes in the treatment of lysosomal storage disorders.
- Because of the specialized skills required for evaluation, diagnosis, and monitoring, approval requires prescription by or consultation with an appropriate specialist.
Background
Mucopolysaccharidosis type I (MPS I) is an autosomal recessive lysosomal storage disease caused by deficiency of α-L-iduronidase, resulting in accumulation of glycosaminoglycans and progressive multiorgan dysfunction. The clinical spectrum ranges from severe (Hurler) to attenuated (Hurler–Scheie and Scheie) phenotypes. Diagnosis is established either by demonstrating deficient α-L-iduronidase activity in leukocytes, fibroblasts, plasma, or serum, or by molecular genetic testing showing biallelic pathogenic or likely pathogenic IDUA variants. Treatment options include hematopoietic stem cell transplantation (HSCT) for selected early severe cases and enzyme replacement therapy with Aldurazyme (laronidase) for somatic manifestations; when covered under this policy, Aldurazyme is approved for up to 1 year when criteria are met, with dosing limited to 0.58 mg/kg per dose administered intravenously no more frequently than once weekly.
Definitions and Diagnostic Criteria
Covered Indications
Confirmation of MPS I diagnosis via molecular genetic testing of IDUA
For coverage consideration, molecular testing must meet the following diagnostic standard:
When molecular testing is used to establish diagnosis, results must document pathogenicity classification for both alleles.
Eligibility Requirements
This block is reserved for an eligibility summary. There are no top-level eligibility nodes beyond the detailed coverage criteria in this policy; eligibility for Aldurazyme coverage requires meeting the diagnostic confirmation, prescriber, and dosing limits specified in the Recommended Authorization Criteria.
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