CurrentBlue Cross Blue Shield - IowaPolicy 05.04.94

Filspari (sparsentan) for primary IgA nephropathy

Defines prior authorization, coverage criteria, dosing/quantity limits, documentation, and prescriber requirements for Filspari (sparsentan) for adults with primary immunoglobulin A nephropathy (IgAN) at risk of rapid progression.

Policy Summary

PayerBlue Cross Blue Shield - Iowa

PolicyFilspari (sparsentan) for primary IgA nephropathy

Policy CodePolicy 05.04.94

Change TypeRevised (January 2026)

Effective DateMar 10, 2026

Next Review Date

Key ActionPrior authorization required with submission of kidney biopsy confirming primary IgAN and chart notes/labs showing proteinuria ≥ 0.5 g/day for initial requests; for continuation, submit documentation of proteinuria or UPCR reduction.

SourceLink

POLICY UPDATE CHANGES

Policy reviewed and revised in January 2026 with current effective date March 10, 2026.

Adults (≥18)Covered Population

≥0.5 g/dayProteinuria threshold

≥30eGFR requirement

9m / 12mAuth durations

Coverage Summary

Scope: This policy defines prior authorization, coverage criteria, dosing/quantity limits, documentation, and prescriber requirements for Filspari (sparsentan) for adults with biopsy‑proven primary immunoglobulin A nephropathy (IgAN) who are at risk for rapid progression. Coverage stance: covered_with_criteria — authorization may be granted when the specified clinical criteria are met (see initial and continuation authorization rules). Safety and regulatory context: Filspari is the first FDA‑approved non‑immunosuppressant for IgAN and has an FDA‑required REMS due to concerns about hepatotoxicity and embryofetal toxicity; these safety issues and other warnings (hypotension, acute kidney injury, hyperkalemia, fluid retention) are noted in the policy and package insert. The policy was reviewed January 2026 with a current effective date of March 10, 2026.

Key thresholds and authorization durations

Proteinuria threshold>= 0.5 g/day

eGFR requirement>= 30 mL/min/1.73m2

Authorization — Initial9 months when initial criteria met (biopsy-confirmed IgAN, age >=18, proteinuria >=0.5 g/day, eGFR >=30, stable/maximally tolerated RAS inhibitor or intolerance)

Authorization — Continuation12 months when member achieves or maintains positive clinical response (reduction in proteinuria or reduction in UPCR) and eGFR >=30 mL/min/1.73m2

Covered populationAdults (>=18 years) with biopsy-proven primary IgAN

Dosing/quantity notesStandard limit 30 tablets/30 days; initiate 200 mg once daily, increase to 400 mg once daily after 14 days as tolerated

Not Medically Necessary / Exclusions

Drug combination exclusions: Requests will be denied if Filspari is to be used in combination with Tarpeyo (budesonide delayed release), Fabhalta (iptacopan), Vanrafia (atrasentan), or Voyxact (sibeprenlimab‑szsi).

Safety precautions: In addition to combination exclusions, prescribers and reviewers must consider REMS‑required safety constraints for Filspari related to hepatotoxicity and embryofetal toxicity, and other contraindications or cautions noted in the label when evaluating requests.

Provider Actions & Operational Requirements

Prior Authorization

Prior authorization required

Prior authorization is required. For initial requests submit: (a) kidney biopsy confirming primary IgAN and (b) chart notes, medical records, or laboratory values showing proteinuria ≥ 0.5 g/day. For continuation requests submit chart notes, medical records, or laboratory values supporting a positive clinical response (e.g., reduction in proteinuria or UPCR).

Documentation Required

Prescriber specialty requirement

Filspari must be prescribed by or in consultation with a nephrologist.

Billing Rule

Quantity limits and dosing guidance

Standard quantity limit: 30 tablets per 30 days. FDA-recommended dosing: initiate 200 mg orally once daily; after 14 days increase to 400 mg once daily as tolerated.

Denial Risk

Drug combination exclusions

Requests will be denied/not authorized if Filspari is used in combination with Tarpeyo (budesonide delayed release), Fabhalta (iptacopan), Vanrafia (atrasentan), or Voyxact (sibeprenlimab-szsi).

Documentation Required

Samples/patient assistance program

Members receiving samples or medication through the manufacturer's patient assistance program must still meet the initial approval criteria to be covered.

Applicable Codes

Drug productNDCCovered

200 mg tablet	Filspari (sparsentan) 200 mg oral tablets; standard limit 30 tablets per 30 days; initiate 200 mg once daily, increase to 400 mg once daily after 14 days as tolerated (FDA recommended dosing)
400 mg tablet	Filspari (sparsentan) maintenance dose 400 mg once daily (per FDA recommended dosing)

Relevant diagnosisICD-10Covered

N/A	Primary immunoglobulin A nephropathy (IgAN) confirmed by kidney biopsy — use ICD-10 code for IgA nephropathy per billing/medical record (policy requires biopsy confirmation and documentation of proteinuria ≥ 0.5 g/day and eGFR ≥ 30 mL/min/1.73m2)

Procedures and billing guidancemixed

Prior authorization	Prior authorization required with submission of kidney biopsy confirming primary IgAN and chart notes/labs showing proteinuria ≥ 0.5 g/day for initial requests; continuation requires documentation of positive clinical response (reduction in proteinuria or UPCR)
Prescriber specialty	Must be prescribed by or in consultation with a nephrologist
Quantity limit	Standard limit = 30 tablets per 30 days
Billing codes guidance	To report provider services, use appropriate CPT, HCPCS, Revenue, and ICD diagnostic codes
Drug combination exclusion	Do not use in combination with Tarpeyo, Fabhalta, Vanrafia, or Voyxact — requests will be denied if combined

Clinical Evidence

45% vs 15% (30% diff)PROTECT trial UPCR reduction at 9 months — 45% reduction with Filspari vs 15% with irbesartan (treatment difference 30%, p<0.0001)

1.2 mL/min/1.73m2/yrTwo-year eGFR slope (final analysis) — treatment effect 1.2 mL/min/1.73m2/year (p=0.0168) favoring Filspari

Evidence context: In the PROTECT randomized trial, Filspari produced a 45% reduction in UPCR at 9 months versus 15% with irbesartan (treatment difference 30%, p<0.0001). Long‑term data showed a favorable effect on kidney function with a 1.2 mL/min/1.73 m2/year treatment effect on eGFR slope at two years (p=0.0168) and durable proteinuria reductions. Safety concerns prompting a REMS include potential hepatotoxicity and embryofetal toxicity; other adverse effects include hypotension, edema, hyperkalemia, and transaminase elevations.

Background & Definitions

Background: Filspari (sparsentan) is an oral endothelin and angiotensin II receptor antagonist indicated to reduce proteinuria and slow kidney function decline in adults with biopsy‑proven primary IgAN at risk for rapid progression. Blockade of endothelin‑1 and angiotensin II pathways reduces proteinuria, protects podocytes, and may prevent glomerulosclerosis. Filspari is the first FDA‑approved non‑immunosuppressant medication for IgAN. Safety concerns include hepatotoxicity and embryofetal toxicity, and the FDA has required a REMS to monitor these risks; other warnings include hypotension, acute kidney injury, hyperkalemia, fluid retention, and transaminase elevations. Definitions referenced in this policy include UPCR (urine protein‑to‑creatinine ratio) and RAS inhibitor (renin‑angiotensin system inhibitor such as ACE inhibitors or ARBs). FDA full approval timing and package insert citations are noted in the policy references.