CurrentmhnPolicy CP.PHAR.619

Clinical Policy: Nedosiran (Rivfloza)

Defines medical necessity criteria, dosing limits, prior authorization and continuation requirements for nedosiran (Rivfloza) for commercial, HIM and Medicaid lines of business, including age, diagnostic confirmation, lab thresholds, dosing by weight/age, exclusions, and approval durations.

Policy Summary

Payermhn

PolicyClinical Policy: Nedosiran (Rivfloza)

Policy CodePolicy CP.PHAR.619

Change TypeAdded codes; revised pediatric dosing & syringe requirement; coverage updates

Effective DateSep 29, 2023

Next Review Date

Key ActionProvider must submit documentation (office chart notes, lab results or other clinical information) supporting diagnosis confirmation, baseline and repeat UOx or UOx:Cr, eGFR, prior pyridoxine trial, current weight, and prescribing specialist consultation as applicable.

POLICY UPDATE CHANGES

Added HCPCS codes C9399 and J3490 to policy.

Revised age and dosing criteria to include children aged ≥ 2 years and added requirement that request must be for a prefilled syringe unless monthly dose is < 128 mg.

Added exclusion for concomitant use of Rivfloza with Oxlumo and added urologists to list of specialist prescribers; changed Commercial approval duration to '6 months or to the member's renewal date, whichever is longer'.

1FDA-approved indication(s)

2Minimum age (years)

≥30Required eGFR threshold (mL/min/1.73 m2)

Coverage Summary

Covered with criteria: Nedosiran (Rivfloza) is covered for primary hyperoxaluria type 1 (PH1) when diagnostic confirmation is provided and other criteria are met. Coverage requires age ≥ 2 years, documented eGFR ≥ 30 mL/min/1.73 m2, diagnostic confirmation of PH1 by AGXT genetic testing or liver biopsy showing AGT deficiency, and a documented trial of pyridoxine (vitamin B6) for at least three months at maximally indicated doses without normalization of urinary oxalate unless contraindicated. Dosing is limited by age/weight: 160 mg/month for ≥50 kg; 128 mg/month for ≥12 years and <50 kg (and for 39–<50 kg in ages 2–11); 3.3 mg/kg/month for children <39 kg. Requests must be for a prefilled syringe unless the monthly dose is 128 mg, and rivfloza must not be prescribed concurrently with Oxlumo.

Quick thresholds & key items

eGFR threshold≥ 30 mL/min/1.73 m2

UOx diagnostic threshold> 0.70 mmol/1.73 m2/24 h (confirmed on repeat testing)

UOx reduction for continuation> 30% decrease from baseline

Minimum age≥ 2 years

Prefilled syringe requirementRequest must be for a prefilled syringe unless monthly dose is < 128 mg

Monthly dose threshold related to syringeMonthly dose < 128 mg exempts prefilled syringe requirement

Initial Therapy Criteria — Primary Hyperoxaluria Type 1

Initial Therapy Criteria — Other Diagnoses/Indications

Initial Approval Criteria - Other Diagnoses/Indications

If the request is for other uses, must meet one of the following:

ANY of the following

Drug label changed within last 6 months and use not yet reflected in policy — follow relevant formulary/no-coverage or non-formulary policy per line of business (references provided CP.CPA.190, HIM.PA.33, CP.PMN.255, HIM.PA.103, CP.PMN.16)
Requested use not listed in Section III and criterion 1 above does not apply — refer to off-label use policy for relevant line of business (CP.CPA.09, HIM.PA.154, CP.PMN.53)

Continuation (Renewal) Criteria

Diagnoses / Indications Not Authorized

Diagnoses/Indications Not Authorized

Non-FDA approved indications not addressed in this policy are not authorized unless sufficient documentation of efficacy and safety per off-label use policies (CP.CPA.09, HIM.PA.154, CP.PMN.53) or evidence of coverage documents

Applicable Codes

HCPCS codes referencedHCPCS

C9399	Unclassified drugs or biologicals
J3490	Unclassified drugs

Provider Actions & Prior Authorization Requirements

Documentation Required

Documentation required for approval

Provider must submit office chart notes, laboratory results, or other clinical information supporting diagnosis confirmation; baseline and repeat UOx or spot UOx:Cr; estimated glomerular filtration rate (eGFR); documentation of prior pyridoxine trial; current body weight (kg); and documentation of prescribing specialist consultation as applicable.

Office notes or chart documentation confirming diagnosis
Baseline and repeat UOx or spot UOx:Cr results
eGFR documentation (must be ≥ 30 mL/min/1.73 m2)
Documentation of prior pyridoxine (vitamin B6) trial
Current body weight in kg
Specialist consultation note when applicable (endocrinologist, hepatologist, nephrologist, urologist, or medical geneticist)

Clinical Evidence & References

Key evidence references: Rivfloza Prescribing Information, Novo Nordisk; March 2025; and the pivotal trial PHYOX2: Baum MA et al., Kidney Int. 2023. Policy aligns with FDA labeling and monitoring requirements per the background and referenced prescribing information.

PHYOX2 (2023)Pivotal randomized trial cited (PHYOX2: Baum et al., Kidney Int. 2023)

Background

Background: Nedosiran is an LDHA-directed siRNA indicated to lower urinary oxalate in children ≥2 years and adults with PH1 with relatively preserved kidney function (eGFR ≥ 30 mL/min/1.73 m2). Policy aligns with FDA labeling and requires diagnostic confirmation (AGXT genetic testing or liver biopsy), a prior pyridoxine trial, weight-based dosing limits and formulation limits (prefilled syringe requirement unless monthly dose is <128 mg), and monitoring of urinary oxalate as specified in the approval and continuation criteria.

Definitions

PH1Primary hyperoxaluria type 1

UOxUrinary oxalate

UOx:CrUrinary oxalate-to-creatinine molar ratio

AGTAlanine glyoxylate aminotransferase

LDHALactate dehydrogenase A

Revision History

1Q 2025Material

Added HCPCS codes C9399 and J3490 to policy.

04.16.25MaterialLatest

Revised age and dosing criteria to include children aged ≥ 2 years and added requirement that request must be for a prefilled syringe unless monthly dose is < 128 mg.

2Q 2024Material

Policy Summary

Payermhn

PolicyClinical Policy: Nedosiran (Rivfloza)

Policy CodePolicy CP.PHAR.619

Change TypeAdded codes; revised pediatric dosing & syringe requirement; coverage updates

Effective DateSep 29, 2023

Next Review Date

On This Page

Documentation Required

Genetic or biopsy confirmation

For diagnosis confirmation submit either genetic testing showing mutations in the AGXT gene or a liver biopsy documenting AGT enzyme deficiency.

Prior Authorization

Prior pyridoxine trial required

Request requires documentation of at least three months of pyridoxine (vitamin B6) at up to maximally indicated doses without normalization of UOx, unless pyridoxine is contraindicated or not tolerated.

Prior Authorization

Dose/formulation restriction

Requests must be for the prefilled syringe formulation unless the monthly dose is < 128 mg. Dosing must not exceed the age- and weight-specific maximums specified in policy.

Weight ≥ 50 kg: 160 mg/month (1 prefilled syringe)
Age ≥ 12 years and < 50 kg: 128 mg/month (1 prefilled syringe)
Age 2-11 years and < 50 kg: <39 kg: 3.3 mg/kg/month; ≥39 kg: 128 mg/month (1 prefilled syringe)

Denial Risk

Concurrent Oxlumo not allowed

Claims or authorizations may be denied if Rivfloza is prescribed concurrently with Oxlumo.

Documentation Required

Response assessment

For continuation, document response as either a >30% decrease in UOx excretion from baseline, or symptomatic improvement together with objective improvement in UOx excretion or spot UOx:Cr.

> 30% reduction in UOx excretion from baseline
Or symptomatic improvement plus decrease in UOx excretion or improvement in spot UOx:Cr