ModifiedMass General Brigham Health PlanPolicy N/A

Beyfortus (nirsevimab)

Defines prior authorization criteria for Beyfortus (nirsevimab) under the pharmacy benefit for children aged ≥8 months to <24 months for prevention of RSV lower respiratory tract disease; notes medical-benefit coverage rules for younger infants and some exceptions.

Policy Summary

PayerMass General Brigham Health Plan

PolicyBeyfortus (nirsevimab)

Policy CodePolicy N/A

Change TypeCriteria revised; PA clarification

Effective DateDec 1, 2025

Next Review Date

Key ActionSubmit PA showing member age (≥8 to <24 months), indication (prevention of RSV LRTD for first or second RSV season), and documentation that the member meets one of the listed high-risk criteria; include recent weight to confirm dosing.

SourceLink

POLICY UPDATE CHANGES

Updated criteria for cystic fibrosis to define severe lung disease and include weight-for-length less than 10th percentile as an approvable characteristic.

Clarified PA requirement applies to pharmacy benefit for members ≥8 months of age; no PA for pharmacy benefit for members up to 8 months and medical benefit coverage without PA.

1Dose approvals per RSV season (standard)

1Additional dose allowed for cardiopulmonary bypass

≥8–<24mCovered age under PA

Coverage Summary

Beyfortus (nirsevimab) is covered with criteria for the pharmacy benefit for children aged ≥8 months to <24 months for prevention of RSV lower respiratory tract disease. The policy aligns with AAP/ACIP guidance and the Beyfortus prescribing information. Medical-benefit coverage is noted for younger infants and some exceptions: Beyfortus is covered under the Medical Benefit without prior authorization and is covered under the pharmacy benefit without prior authorization for members up to 8 months of age.

Key thresholds and statistics

Covered age under PA≥8 months to <24 months

Pharmacy coverage without PA<8 months

Standard approval duration1 dose for 6 months from the RSV season onset date

Additional dose allowed for cardiopulmonary bypass1

Dose approvals per RSV season (standard)1

Authorization Criteria (Pharmacy Benefit)

Authorization Criteria (Pharmacy Benefit) for Beyfortus in second RSV season or first/second season for eligible children 63;8 to <24 months

Authorization may be granted when ALL of the following are met:

Medical Benefit / Pharmacy Benefit Exceptions

ANY of the following

Beyfortus is covered under the Medical Benefit without prior authorization (PA)
Beyfortus is covered under the pharmacy benefit without PA up to 8 months of ageUp to 8 months

Prior Authorization

Prior authorization applies for pharmacy benefit ages ≥8 to <24 months

Prior authorization (PA) is required under the pharmacy benefit for members aged ≥8 months to <24 months. For members up to 8 months of age, Beyfortus is covered under the pharmacy benefit without PA. Beyfortus administered under the medical benefit is covered without prior authorization.

Provider Actions & Documentation Requirements

Prior Authorization

Prior authorization required for pharmacy benefit for ages ≥8 to <24 months

Submit a prior authorization request confirming the member is ≥8 months to <24 months, that the request is for prevention of RSV lower respiratory tract disease in the first or second RSV season, and documentation that the member meets at least one listed high-risk criterion. Include recent weight to confirm appropriate dosing per the dosing table.

Member age: ≥8 months to <24 months
Indication: prevention of RSV LRTD for first or second RSV season
Documentation of one qualifying high-risk criterion from the policy
Provide recent weight to confirm dose per dosing table

Documentation Required

Document dosing weight

Applicable Codes

Benefit / Program Indicators (informational)mixed

No codes listed

Background & Clinical Evidence

Beyfortus (nirsevimab) is an RSV F protein-directed fusion inhibitor indicated to prevent RSV lower respiratory tract disease in neonates and infants during their first RSV season and in children up to 24 months who remain vulnerable in their second season. This policy aligns with AAP and ACIP recommendations and the Beyfortus prescribing information.

Key guidance sources:

• American Academy of Pediatrics (AAP) recommendations

• ACIP and AAP recommendations for nirsevimab

• Beyfortus (nirsevimab) prescribing information (AstraZeneca, August 2024)

• NEJM clinical trial: Hammitt et al., N Engl J Med. 2022

Definitions

Definitions:

• RSV season onset date: Not specifically defined in this policy; used to calculate the standard 6-month approval duration.

• Severely immunocompromised: Term is used as an approvable characteristic but is not further defined in this policy document.

Revision History

2025-12-01policy_updateLatest

Updated criteria for cystic fibrosis to define severe lung disease and include weight-for-length less than 10th percentile as an approvable characteristic; reflected in criteria where CF requires either history of hospitalization for pulmonary exacerbation or persistent chest imaging abnormalities, or weight-for-length <10th percentile.

2025-12-01clarificationLatest

Clarified prior authorization (PA) requirement applies to the pharmacy benefit for members ≥8 months of age; no PA for pharmacy benefit for members up to 8 months and Beyfortus is covered under the medical benefit without PA.