CurrentCignaPolicy N/A

POLICY: Phenylketonuria - Sephience Prior Authorization Policy

Prior authorization policy for Sephience (sepiapterin oral powder) for treatment of hyperphenylalaninemia in patients with sepiapterin-responsive phenylketonuria; defines initial and continuation approval criteria, exclusions (concomitant sapropterin), prescriber requirements, dosing/titration guidance, and approval durations.

Policy Summary

PayerCigna

PolicyPOLICY: Phenylketonuria - Sephience Prior Authorization Policy

Policy CodePolicy N/A

Change TypeCriteria expansion; exclusion update; policy creation/review

Effective DateN/A

Next Review DateN/A

Key ActionPrior authorization is recommended for Sephience; initial approval requires prescription by or in consultation with a metabolic disease specialist.

SourceLink

POLICY UPDATE CHANGES

For a patient currently receiving Sephience, 'patient has achieved a blood phenylalanine concentration ≤ 360 micromol/L' was added as an option for demonstrating clinical response.

Conditions Not Covered: added Zelvysia to the list of sapropterin products for which concurrent use with Sephience is not covered.

New Policy created with review dates 07/30/2025 and 10/29/2025 in history.

1Covered Indication (PKU)

4Continuation response options

60 mg/kgMaximum daily dose

Coverage Summary

Sephience (sepiapterin) is covered with criteria for the FDA‑approved indication of sepiapterin‑responsive phenylketonuria (PKU) and must be prescribed by or in consultation with a metabolic disease specialist. The drug is intended to be used in conjunction with a phenylalanine‑restricted diet. Initial approvals are authorized for 12 weeks; patients currently receiving Sephience may be approved for 1 year when continuation criteria are met. Concurrent use with sapropterin products (Kuvan, Javygtor, Zelvysia, generic) is excluded and not covered.

Initial Therapy Criteria

A) Initial Therapy

Initial approval - duration: Approve for 12 weeks
Dietary requirement: The medication is prescribed in conjunction with a phenylalanine-restricted diet
Prescriber requirement: The medication is prescribed by or in consultation with a metabolic disease specialist (or specialist who focuses on the treatment of metabolic diseases)

Continuation Therapy Criteria

Operational & Dosing Requirements

Billing Rule

Approval durations

If approved as initial therapy, authorize for 12 weeks. If the patient is currently receiving Sephience, authorize for 1 year. Patients with <12 weeks of prior therapy or who are restarting therapy should be considered initial therapy.

Prior Authorization

Prior authorization required

Prior authorization is required. Initial approval requires the medication to be prescribed by or in consultation with a metabolic disease specialist (or specialist who focuses on the treatment of metabolic diseases).

Conditions Not Covered / Exclusions

Conditions Not Covered

Sephience is considered not medically necessary for concurrent therapy as specified.

Conditions Not Covered - Concurrent use with sapropterin: Concurrent use with sapropterin (Kuvan, Javygtor, Zelvysia, generic) is not covered

Rationale: no data available regarding combination use of sapropterin and Sephience

Applicable Codes

No codes specified in policy textmixed

No codes listed

Clinical Evidence

66%Of 156 patients, 103 (66%) had ≥30% decrease in blood Phe (part one responsiveness)

7%Of 156 patients, 11 (7%) had 15%–<30% decrease in blood Phe (part one)

Biochemical response to Sephience is determined by a therapeutic trial because response generally cannot be predicted by laboratory testing. A ≥ 30% reduction in blood phenylalanine (Phe) is widely accepted as indicative of responsiveness, though lower thresholds (for example, ≥ 20% or even 15%) may be clinically meaningful in some patients. For policy continuation, acceptable response options include achieving a blood Phe ≤ 360 micromol/L or a ≥ 20% reduction from pre‑treatment baseline (other options include prescriber‑reported clinical response or increased dietary Phe tolerance).

Definitions

Clinical response: May include prescriber‑reported cognitive and/or behavioral improvements, reduction in blood Phe, increased dietary Phe tolerance, or attainment of target Phe levels.

Phenylalanine‑restricted diet: Dietary therapy to limit phenylalanine intake; use of Sephience is required to be in conjunction with a Phe‑restricted diet.

Revision History

07/30/2025policy_creation/review

New Policy created; Review Date 07/30/2025.

07/30/2025material_change

For a patient currently receiving Sephience, 'patient has achieved a blood phenylalanine concentration ≤ 360 micromol/L' was added as an option for demonstrating clinical response. (This change expands continuation response criteria.)

07/30/2025material_change

Conditions Not Covered: added Zelvysia to the list of sapropterin products for which concurrent use with Sephience is not covered. (Updates the list of sapropterin products excluded from concomitant use.)