CurrentNeighborhood Health Plan of Rhode IslandPolicy N/A

Strensiq (asfotase alfa) — coverage criteria for perinatal/infantile- and juvenile-onset hypophosphatasia

Clinical coverage criteria for use of Strensiq (asfotase alfa) to treat perinatal/infantile- and juvenile-onset hypophosphatasia (HPP) for Neighborhood Health Plan of Rhode Island members across Medicaid, Commercial, and Medicare‑Medicaid Plan scopes.

Policy Summary

PayerNeighborhood Health Plan of Rhode Island

PolicyStrensiq (asfotase alfa) — coverage criteria for perinatal/infantile- and juvenile-onset HPP

Policy CodePolicy N/A

Change TypeNo material change

Effective Date03/01/2018

Next Review DateN/A

Key ActionSubmit prior authorization with ALPL genetic test results, serum ALP, TNSALP substrate levels, baseline ophthalmology and renal ultrasound, and recent weight to demonstrate diagnosis and meet dosing limits.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

6 monthsInitial coverage duration

6 monthsRenewal coverage duration

2018-2025Policy reviewed dates range

J3490HCPCS/CPT code

Coverage Criteria for Strensiq (asfotase alfa)

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Initial Therapy

Covered when ALL of the following are met for perinatal/infantile- or juvenile-onset HPP:

Prescriber and diagnosis: Prescriber is an endocrinologist or specialist in the treatment of perinatal/infantile or juvenile hypophosphatasia (HPP); patient clinically diagnosed with perinatal/infantile- or juvenile-onset HPP with onset prior to 18 years of age; supporting documentation of diagnosis prior to 18 years provided; patient has clinical signs and/or symptoms of HPP as supported by clinical notes

Diagnostic support: Diagnosis supported by either molecular genetic testing showing an ALPL gene mutation OR by all of the specified radiographic and clinical features

When genetic testing is not available, radiographic imaging plus the listed clinical features must be provided

Radiographic/clinical features (when used instead of genetic testing): Radiographic imaging demonstrating skeletal abnormalities supporting HPP (e.g., infantile rickets, alveolar bone loss, osteoporosis, low bone mineral content for age) AND clinical features such as craniosynostosis with increased intracranial pressure; rachitic chest deformity with respiratory compromise; limb deformity with delayed walking or gait abnormality; compromised exercise capacity due to rickets and muscle weakness; low BMD with unexplained fractures; alveolar bone loss with premature loss of primary (deciduous) teeth

Laboratory and baseline assessments: Low baseline serum alkaline phosphatase (ALP) below the laboratory age-/gender-specific reference range AND elevated TNSALP substrate level (e.g., serum PLP, serum or urine PEA, urinary PPi); baseline ophthalmology exam provided; baseline renal ultrasound provided; member weight documented within 30 days of request

Dosing: Dose no greater than 2 mg/kg three times weekly and appropriate vials must be used<= 2 mg/kg three times weekly

Renewal Therapy

Renewal covered when ALL of the following are met:

Clinical benefit: Documentation shows Strensiq has been effective and the patient is responding to treatment, demonstrated by improvements such as weight gain, increased height velocity, improved ventilator/respiratory status, improved skeletal manifestations (e.g., bone mineralization, fractures, deformities, RGI-C), or improved motor function/mobility (e.g., MPOMA-G, 6-minute walk, TUG, Chair Rise, LEFS)

Tolerability: Patient is tolerating therapy with Strensiq

Monitoring: Documented ophthalmology exam once yearly to monitor ectopic calcifications and documented renal ultrasound once yearly to monitor ectopic calcificationsannual

All therapies are considered investigational when used at a dose or for a condition other than recognized medically accepted indications. Neighborhood Health Plan of Rhode Island does not provide coverage for drugs used for investigational purposes. Accepted indications are those supported by standard reference compendia (e.g., AHFS‑DI, Micromedex, Clinical Pharmacology, Lexi‑Drugs) or peer‑reviewed published medical literature demonstrating sufficient evidence for use.

Use of Strensiq (asfotase alfa) for indications other than perinatal/infantile‑ or juvenile‑onset hypophosphatasia, or without the required diagnostic, laboratory, and documentation support, is not covered / may be considered not medically necessary. Required documentation includes molecular genetic testing results for the ALPL gene or, when genetic testing is not available, radiographic imaging plus the listed clinical features; serum alkaline phosphatase (ALP) level; tissue‑non‑specific alkaline phosphatase (TNSALP) substrate level; and supporting clinical notes demonstrating onset prior to 18 years.

Provider Actions and Authorization Requirements

Prior Authorization

Prior Authorization Required

Prior authorization is required for initial coverage of Strensiq (asfotase alfa). Requests must include a clinician attestation and all required supporting documentation to allow medical necessity review prior to dispensing.

Prior authorization required for all payers listed in scope (Medicaid, Commercial, Medicare‑Medicaid Plan) for initial therapy
Prescriber should be an endocrinologist or specialist in treatment of perinatal/infantile or juvenile hypophosphatasia (HPP)
Dose requests should not exceed 2 mg/kg three times weekly and appropriate vial sizes must be used

Step Therapy

Step Therapy Exemption for Recent MMP Recipients

Members of the Medicare‑Medicaid Plan (MMP) who have received this medication within the past 365 days are exempt from Step Therapy requirements for re‑initiation or continuation of treatment.

Step therapy exemption applies when member documentation shows receipt of Strensiq within the prior 365 days
Exemption timeframe: 365 days from last documented administration

Denial Risk

Documentation Missing or Criteria Not Met

If required documentation is missing or criteria are not met, the request will be denied. Providers must submit missing information or correct documentation to allow reconsideration.

Denial will be issued when supporting documentation is incomplete or absent (see required items below)
On denial, provider may submit additional documentation or request reconsideration per payer instructions
Common missing items: ALPL molecular genetic testing results, baseline serum ALP level, TNSALP substrate levels (e.g., PLP, PEA, urinary PPi), radiographic imaging, baseline ophthalmology exam, baseline renal ultrasound, and recent member weight

Background

Hypophosphatasia (HPP) is a rare metabolic bone disorder caused by deficiency of tissue‑non‑specific alkaline phosphatase (TNSALP), most commonly due to mutations in the ALPL gene. Deficient TNSALP activity leads to accumulation of TNSALP substrates (for example, pyridoxal‑5‑phosphate and inorganic pyrophosphate), resulting in impaired skeletal mineralization and a spectrum of clinical manifestations. Perinatal and infantile presentations include generalized hypomineralization, rachitic features, chest deformities with rib fractures, respiratory compromise, failure to thrive, hypotonia, seizures, and nephrocalcinosis; juvenile‑onset disease presents with skeletal abnormalities such as limb deformities, delayed walking, low bone mineral content, premature loss of primary teeth, and compromised exercise capacity due to rickets and muscle weakness.

Definitions

inv-12: Perinatal/infantile- or juvenile-onset HPP — diagnostic criteria, age cutoffs, and supporting clinical/laboratory findings

Definition / age cutoffPerinatal/infantile- or juvenile-onset HPP: clinical diagnosis with onset prior to 18 years of age

Required genetic supportMolecular genetic testing demonstrating an ALPL mutation OR radiographic plus clinical features when genetic testing unavailable

Key laboratory findingsLow baseline serum alkaline phosphatase (ALP) below age/gender reference range and elevated TNSALP substrates (e.g., PLP, PEA, urinary PPi)

Supporting radiographic/clinical featuresRadiographic evidence of skeletal abnormalities (infantile rickets, alveolar bone loss, low BMD) and features such as craniosynostosis, rachitic chest deformity with respiratory compromise, limb deformity with delayed walking, compromised exercise capacity

Baseline assessments requiredBaseline ophthalmology exam and baseline renal ultrasound required

OpenPayer

Strensiq (asfotase alfa) — coverage criteria for perinatal/infantile- and juvenile-onset hypophosphatasia

Coverage Criteria for Strensiq (asfotase alfa)

Coding and Dosing

Provider Actions and Authorization Requirements

Background

Definitions