Subject: Strensiq 1974-A SGM P2023
Policy:
I. INDICATIONS
The indications below including FDA-approved indications and
compendial uses are considered a covered benefit provided that
all the approval criteria are met and the member has no
exclusions to the prescribed therapy.
FDA-Approved Indication
Strensiq is indicated for the treatment of patients with
perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).
All other indications are considered experimental/investigational
and not medically necessary.
II. DOCUMENTATION
Submission of the following information is necessary to initiate
the prior authorization review:
A. Initiation of therapy:
1. Documentation of presence of condition before the age of
18, if applicable
2. Documentation confirming diagnosis which includes one
of the following:
a. Genetic testing results confirming a mutation in the
ALPL gene, or
b. Submission of ALL of the following:
i. Radiographic imaging demonstrating skeletal
abnormalities (See Appendix B)
ii. A serum alkaline phosphatase (ALP) level below
the gender and age-specific reference range of
the laboratory performing the test
iii. Elevated tissue non-specific alkaline phosphatase
(TNSALP) substrate level (e.g., serum pyridoxal
5-phosphate (PLP) level, urine
phosphoethanolamine (PEA) level, or urinary or
plasma inorganic pyrophosphate (PPi) level)
B. Continuation of therapy:
Medical records of at least one of the following to document
benefit to therapy:
1. Radiographic Global Impression of Change (RGI-C) rating
2. Height and weight measurements as measured by z-
scores
3. Modified Performance Oriented Mobility Assessment-Gait
(MPOMA-G) score
4. Distance walked in the 6 Minute Walk Test (6MWT)
5. Timed Up & Go (TUG) Test
6. Chair Rise Test
7. Lower Extremity Function Scale (LEFS)
III. CRITERIA FOR INITIAL APPROVAL
Perinatal/infantile- and juvenile-onset hypophosphatasia
(HPP)
Authorization of 12 months may be granted for treatment of HPP
when all of the following criteria are met:
A. The member has clinical signs and/or symptoms of
hypophosphatasia (See Appendix A).
B. The onset of the disease was perinatal/infantile or juvenile. If
the member is 18 years of age or older at the time of the
request, documentation of the presence of the condition
before the age of 18 must be provided (e.g., member began
experiencing symptoms at age 10).
C. The diagnosis was confirmed by one of the following (1 or 2):
1. The presence of a known pathological mutation in the
ALPL gene as detected by ALPL molecular genetic testing
2. The diagnosis is supported by ALL of the following:
a. Radiographic imaging demonstrating skeletal
abnormalities (See Appendix B)
b. A serum alkaline phosphatase (ALP) level below the
gender- and age-specific reference range of the
laboratory performing the test
c. Elevated tissue-nonspecific alkaline phosphatase
(TNSALP) substrate level (e.g., serum PLP level, urine
PEA level, or urinary or plasma PPi level) as defined
by the laboratory performing the test
D. Member’s weekly dose will not exceed the following:
1. 9 mg/kg weekly in a member with perinatal/infantile-
onset HPP
2. 6 mg/kg weekly in a member with juvenile-onset HPP
IV. CONTINUATION OF THERAPY
Authorization of 12 months may be granted for continued
treatment in members requesting reauthorization for an
indication listed in Section III who are currently receiving the
requested medication through a paid pharmacy or medical
benefit when both of the following are met:
A. Member is experiencing benefit from therapy as
demonstrated by one of the following:
1. Member has experienced improvement in skeletal
manifestations from baseline as assessed by the
Radiographic Global Impression of Change (RGI-C) scale
2. Member is less than 18 years of age and has experienced
an improvement in height and weight compared to
baseline, as measured by z-scores
3. Member has experienced an improvement in step length
by at least 1 point in either foot compared to baseline
based on the Modified Performance Oriented Mobility
Assessment-Gait (MPOMA-G) scale
4. Member has experienced an improvement in 6 Minute
Walk Test compared to baseline
5. Member has experienced an improvement in Timed Up &
Go (TUG) Test compared to baseline
6. Member has experienced an improvement in Chair Rise
Test compared to baseline
7. Member has experienced an improvement in Lower
Extremity Function Scale (LEFS) compared to baseline
B. Member’s weekly dose will not exceed the following:
1. 9 mg/kg weekly in a member with perinatal/infantile-
onset HPP
2. 6 mg/kg weekly in a member with juvenile-onset HPP
V. APPENDIX
Appendix A. Examples of Signs and Symptoms of HPP
A. Perinatal/infantile-onset HPP:
• Generalized hypomineralization with rachitic features,
chest deformities and rib fractures
• Skeletal abnormalities (e.g., short limbs, abnormally
shaped chest, soft skull bone)
• Respiratory problems (e.g., pneumonia)
• Hypercalcemia
• Failure to thrive
• Severe muscular hypotonia and weakness
• Nephrocalcinosis secondary to hypercalciuria
• Swallowing problems
• Seizures
B. Juvenile-onset HPP:
• Premature loss of deciduous teeth
• Failure to thrive with anorexia, nausea, and
gastrointestinal problems
• Short stature with bowed legs or knock knees
• Skeletal deformities (e.g., enlarged wrist and ankle joints,
abnormal skull shape)
• Bone and joint pain
• Rickets
• Fractures
• Delayed walking
•Waddling gait
Appendix B. Examples of Radiographic Findings that Support HPP
Diagnosis
• Infantile rickets
• Alveolar bone loss
• Focal bony defects of the metaphyses
• Metatarsal stress fractures or metaphyseal fractures
• Osteomalacia with lateral pseudofractures
• Osteopenia, osteoporosis, or low bone mineral content for
age (as detected by dual-energy x-ray absorptiometry
[DEXA])
• Prenatal long bone bowing with osteochondral spurs
Place of Service:
Outpatient
The above policy is based on the following references:
- Strensiq [package insert]. Boston, MA: Alexion Pharmaceuticals, Inc.; June 2020.
- Bianchi ML. Hypophosphatasia: an overview of the disease and its treatment. Osteoporos Int. 2015; 26(12):2743-57.
- Mornet E, Nunes ME. Hypophosphatasia. GeneReviews [Internet]. Available at http://www.ncbi.nlm.nih.gov/books/NBK1150 Updated March 30, 2023. Accessed August 3, 2023.
- Whyte, MP. Hypophosphatasia: An overview for 2017. Bone. 2017;102:15-25.
Copyright Aetna Inc. All rights reserved. Pharmacy Clinical Policy Bulletins are developed by Aetna to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. This Clinical Policy Bulletin contains only a partial, general description of plan or program benefits and does not constitute a contract. Aetna does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Aetna or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. This Clinical Policy Bulletin may be updated and therefore is subject to change.
March 19, 2024
