CurrentHealth NetPolicy CP PHAR.155

Clinical Policy: Cysteamine oral (Cystagon, Procysbi)

Medical necessity criteria and authorization rules for oral cysteamine formulations (Cystagon and Procysbi) for treatment of nephropathic cystinosis for Health Net/Centene lines of business.

Policy Summary

PayerHealth Net

PolicyClinical Policy: Cysteamine oral (Cystagon, Procysbi)

Policy CodePolicy CP PHAR.155

Change TypeMaterial clinical updates

Effective Date02.16

Next Review Date

Key ActionSubmit prior authorization with diagnosis confirmation and supporting documentation; Procysbi requests require prior use of Cystagon unless contraindicated.

SourceLink

POLICY UPDATE CHANGES

Added prescriber requirement that drug be prescribed by or in consultation with a nephrologist or a metabolic disease specialist experienced in management of nephropathic cystinosis.

Added requirement that request is not for combination use of Procysbi and Cystagon for initial criteria.

Clarified diagnostic confirmation by leukocyte cystine concentration must be above the upper limit of normal for the reporting laboratory.

1.95max dose (g/m2/day)

6 moinitial approval

12 mocontinued approval

≥1 yrProcysbi age

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Coverage Criteria for Oral Cysteamine

Initial Therapy

Covered when ALL of the following are met:

Initial Approval for Cystagon or Procysbi: 1) Diagnosis of nephropathic cystinosis confirmed by one of: (a) increased leukocyte cystine concentration above the upper limit of the normal reference range for the reporting laboratory (reported in nmol half‑cystine/mg protein), (b) corneal crystals on slit‑lamp examination, or (c) CTNS gene mutation; 2) Prescribed by or in consultation with a nephrologist or a metabolic disease specialist experienced in management of nephropathic cystinosis; 3) If Procysbi is requested, member must use Cystagon first unless contraindicated or clinically significant adverse effects are experienced; 4) Request is not for combination use of Procysbi and Cystagon; 5) Dose does not exceed 1.95 g/m2 per day.dose <= 1.95 g/m2/day

Approval duration: 6 months

Continuation Therapy

Covered when ALL of the following are met:

Continued Therapy for members already receiving cysteamine: 1) Member is currently receiving medication via the Centene benefit or has previously met initial approval criteria; 2) Member is responding positively to therapy as evidenced by improvement in leukocyte cystine concentration within the past 3 months; 3) If request is for a dose increase, new dose does not exceed 1.95 g/m2 per day.dose <= 1.95 g/m2/day

Approval duration: 12 months

Requests for indications that are non‑FDA approved and are not specifically addressed in this policy are not authorized unless the provider supplies sufficient supporting documentation per the applicable off‑label use policy or evidence of coverage. See the off‑label use policy referenced in the related policies for required clinical justification and documentation standards.

Requests for concurrent use of Procysbi and Cystagon are not authorized.

Uses that are not on the plan formulary/PDL or are non‑FDA indications may be considered not covered unless an appropriate off‑label justification is provided. Follow the line‑of‑business specific formulary/no‑coverage and off‑label policies cited in this document for instructions: CP.CPA.190, HIM.PA.33/HIM.PA.103, CP.PMN.255/CP.PMN.16 and the off‑label policies (CP.CPA.09, HIM.PA.154, CP.PMN.53) as applicable.

Diagnostic and Laboratory Criteria

Leukocyte cystine concentration — diagnostic threshold

Key diagnostic thresholdLeukocyte (white blood cell) cystine concentration above the upper limit of the normal reference range for the reporting laboratory (reported in nmol half‑cystine/mg protein)

Where used in criteriaAcceptable diagnostic confirmation for initial approval of cysteamine therapy (one of the options listed under Initial Approval Criteria)

Reporting conventionThreshold is laboratory‑specific; use the upper limit of normal reported by the testing laboratory

Related approval noteDiagnostic confirmation language clarified in policy update to require 'above the upper limit of the normal reference range for the reporting laboratory'

Prior Authorization, Documentation, and Prescriber Requirements

Prior Authorization

Prior authorization and approval durations

Prior authorization requires a documented diagnosis of nephropathic cystinosis and meeting the applicable initial or continued therapy criteria. Initial approvals are issued for 6 months; continued therapy approvals are issued for 12 months.

Step Therapy

Step requirement: try Cystagon first

If Procysbi is requested for initial therapy, the member must have previously used Cystagon unless it is contraindicated or the member experienced clinically significant adverse effects.

Step Therapy

Procysbi requires prior Cystagon; no combination for initial therapy

Procysbi requests require prior use of Cystagon unless contraindicated or significant adverse effects occurred; requests for combination use of Procysbi and Cystagon for initial therapy are not authorized.

Background and Clinical Context

Nephropathic cystinosis is an inherited disorder of intracellular cystine transport that results in accumulation of cystine within lysosomes. Treatment with oral cysteamine (immediate‑release Cystagon or delayed‑release Procysbi) lowers leukocyte cystine concentration, the biochemical marker used to monitor therapy. Procysbi is a delayed‑release formulation designed for twice‑daily dosing and has been shown to be non‑inferior to immediate‑release Cystagon with respect to steady‑state leukocyte (WBC) cystine reduction in clinical studies.

Definitions and Abbreviations

Definition — cystinosin (CTNS)

Termcystinosin, lysosomal cystine transporter (CTNS)

AbbreviationCTNS — used as the gene name encoding cystinosin

Clinical contextMutations in CTNS are an accepted diagnostic confirmation for nephropathic cystinosis under initial approval criteria

Definition — WBC cystine target and Procysbi vs Cystagon

WBC cystine goalGoal of cysteamine therapy is reduction (depletion) of white blood cell (WBC) cystine concentration; Procysbi demonstrated non‑inferiority to Cystagon for steady‑state WBC cystine levels in a clinical trial

Target measurementWBC cystine reported in nmol half‑cystine/mg protein and used to document response to therapy (improvement within the past 3 months required for continued approval)