CurrentAnthemPolicy CC-0186

Margenza (margetuximab-cmkb) — Coverage Criteria for Metastatic HER2‑Positive Breast Cancer

Clinical prior authorization and medical necessity criteria for Margenza (margetuximab-cmkb) injection for members receiving care under Anthem plans; applies to requests for treatment of HER2-positive metastatic or unresectable breast cancer.

Policy Summary

PayerAnthem

PolicyMargenza (margetuximab-cmkb) — Coverage Criteria for Metastatic HER2‑Positive Breast Cancer

Policy CodePolicy CC-0186

Change TypeRevised

Effective Date03/26/2026

Next Review DateN/A

Key ActionObtain prior authorization and document HER2 positivity and history of ≥2 prior anti‑HER2 regimens, including ≥1 in the metastatic setting; plan Margenza with an allowed chemotherapy.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

≥2required prior anti-HER2 therapies for approval

J9353billing code for Margenza (5 mg)

2ANCCN evidence category referenced

Metastatic HER2+indication covered with criteria

Coverage Criteria for Margenza (margetuximab-cmkb)

Policy Summary

PayerAnthem

PolicyMargenza (margetuximab-cmkb) — Coverage Criteria for Metastatic HER2‑Positive Breast Cancer

Policy CodePolicy CC-0186

Change TypeRevised

Effective Date03/26/2026

Next Review DateN/A

Key ActionObtain prior authorization and document HER2 positivity and history of ≥2 prior anti‑HER2 regimens, including ≥1 in the metastatic setting; plan Margenza with an allowed chemotherapy.

SourceLink

On This Page

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Age or diagnosis: Patient is under 19 years OR has metastatic HER2-positive breast cancer confirmed by IHC 3+ or ISH positive

Document HER2 testing per ASCO/CAP definitions

Disease extent: Recurrent unresectable or metastatic disease

Prior therapy: At least two prior anti-HER2 therapies, with at least one given in the metastatic setting>=2 prior anti-HER2 regimens

Per FDA label and supported by NCCN category 2A

Concomitant therapy: Planned use in combination with chemotherapy (capecitabine, eribulin, gemcitabine, or vinorelbine)

Per NCCN 2A

Regimen	Indication / line of therapy	Coverage status
Margetuximab in combination with capecitabine	For metastatic or recurrent unresectable HER2-positive breast cancer after ≥2 prior anti‑HER2 regimens (at least one in the metastatic setting)	Covered
Margetuximab in combination with eribulin	For metastatic or recurrent unresectable HER2-positive breast cancer after ≥2 prior anti‑HER2 regimens (at least one in the metastatic setting)	Covered
Margetuximab in combination with gemcitabine	For metastatic or recurrent unresectable HER2-positive breast cancer after ≥2 prior anti‑HER2 regimens (at least one in the metastatic setting)	Covered
Margetuximab in combination with vinorelbine	For metastatic or recurrent unresectable HER2-positive breast cancer after ≥2 prior anti‑HER2 regimens (at least one in the metastatic setting)	Covered

Requests for Margenza (margetuximab-cmkb) may not be approved for indications that do not meet the coverage criteria above. Specifically, authorization will be denied when the required clinical elements — documented metastatic or recurrent unresectable HER2‑positive breast cancer, evidence of HER2 positivity per ASCO/CAP, prior exposure to at least two anti‑HER2 regimens (including ≥1 in the metastatic setting), and use in combination with an allowed chemotherapy agent — are not present.

Coding (HCPCS & ICD-10) and Biomarker Thresholds

HCPCSHCPCSCovered

J9353

Injection, margetuximab-cmkb, 5 mg [Margenza]

ICD-10 DiagnosisICD-10

C50.011-C50.A2	Malignant neoplasm of breast
C79.81	Secondary malignant neoplasm of breast
Z85.3	Personal history of malignant neoplasm of breast

HER2 IHC/ISH positivity thresholds — ASCO/CAP examples

IHC 3+ definitionCircumferential membrane staining that is complete, intense in a homogeneous and contiguous population and within >10% of invasive tumor cells.

Single‑probe ISH positiveAverage HER2 copy number ≥ 6.0 signals/cell (observed in a homogeneous/contiguous population and within >10% of invasive tumor cells).

Dual‑probe ISH positive — ratio ≥2.0, HER2 ≥4.0HER2/CEP17 ratio ≥2.0 with average HER2 copy number ≥4.0 signals/cell.

Dual‑probe ISH positive — ratio ≥2.0, HER2 <4.0HER2/CEP17 ratio ≥2.0 with average HER2 copy number <4.0 signals/cell (meets positive criteria).

Dual‑probe ISH positive — ratio <2.0, HER2 ≥6.0HER2/CEP17 ratio <2.0 with average HER2 copy number ≥6.0 signals/cell (meets positive criteria).

Biomarker Requirements (HER2 / ERBB2)

HER2 (ERBB2) — ASCO/CAP positivity criteria

Accepted biomarker for eligibilityIHC 3+ by ASCO/CAP or ISH positive per ASCO/CAP criteria (see ISH thresholds).

IHC 3+ criteria (text)Circumferential membrane staining that is complete, intense and observed in a homogeneous and contiguous population within >10% of invasive tumor cells.

ISH positive examplesSingle‑probe average HER2 ≥6.0 signals/cell; dual‑probe HER2/CEP17 ratio ≥2.0 with average HER2 ≥4.0 signals/cell; or ratio <2.0 with average HER2 ≥6.0 signals/cell.

Definitions (HER2 Status)

IHC 3+ or ISH positive — ASCO/CAP examples

Primary positive definitionIHC 3+ (complete, intense circumferential membrane staining in >10% of invasive tumor cells) or ISH positive per ASCO/CAP thresholds.

ISH single‑probe thresholdAverage HER2 copy number ≥6.0 signals/cell (positive).

ISH dual‑probe ratio thresholdHER2/CEP17 ratio ≥2.0 with average HER2 ≥4.0 signals/cell (positive).

Alternate dual‑probe positive scenarioHER2/CEP17 ratio <2.0 with average HER2 copy number ≥6.0 signals/cell (positive).

Equivocal and negative HER2 per ASCO/CAP

IHC 2+ (equivocal)Circumferential membrane staining that is incomplete and/or weak/moderate and within >10% of invasive tumor cells, or complete/intense staining within ≤10% of invasive tumor cells.

ISH equivocal thresholdsSingle‑probe average HER2 copy number ≥4.0 and <6.0 signals/cell; or dual‑probe HER2/CEP17 ratio <2.0 with average HER2 copy number ≥4.0 signals/cell.

IHC negative (1+ or 0)IHC 1+: incomplete, faint/barely perceptible membrane staining in >10% of tumor cells; IHC 0: no staining or incomplete faint staining in ≤10% of tumor cells.

ISH negativeSingle‑probe average HER2 <4.0 signals/cell; or dual‑probe HER2/CEP17 ratio <2.0 with average HER2 copy number <4.0 signals/cell.

Provider Actions, Prior Authorization & Documentation

Prior Authorization

Prior Authorization Required

Prior authorization required. Requests for Margenza (margetuximab-cmkb) must meet clinical criteria described below before approval.

Policy: CC-0186
Drug: Margenza (margetuximab-cmkb)

Step Therapy

Step Therapy Requirement

Step therapy requirement: member must have received at least two prior anti‑HER2 regimens, with at least one given in the metastatic setting, before Margenza is covered.

Documentation Required

Required Documentation

Documentation must include HER2 testing confirming either IHC 3+ or positive ISH, documentation of recurrent unresectable or metastatic disease, and records showing prior anti‑HER2 therapies (including one given in the metastatic setting). Also include planned chemotherapy partner (capecitabine, eribulin, gemcitabine, or vinorelbine) if applicable.

Denial Risk

Denial Triggers

Requests may be denied if criteria are not met, including: diagnosis is not metastatic or recurrent unresectable disease; HER2 testing does not confirm IHC 3+ or positive ISH; insufficient prior anti‑HER2 therapy (fewer than two regimens or none in the metastatic setting); or Margenza is not being used in combination with an allowed chemotherapy agent. Requests for other indications are not covered.

Covered Regimens and Drug Use

Combination regimen	Supporting evidence / notes	Coverage status
Margetuximab + capecitabine	Allowed per label and NCCN 2A for use in adults with metastatic or recurrent unresectable HER2+ breast cancer after ≥2 prior anti‑HER2 therapies (≥1 in metastatic setting)	Covered
Margetuximab + eribulin	Allowed per label and NCCN 2A for use in adults with metastatic or recurrent unresectable HER2+ breast cancer after ≥2 prior anti‑HER2 therapies (≥1 in metastatic setting)	Covered
Margetuximab + gemcitabine	Allowed per label and NCCN 2A for use in adults with metastatic or recurrent unresectable HER2+ breast cancer after ≥2 prior anti‑HER2 therapies (≥1 in metastatic setting)	Covered
Margetuximab + vinorelbine	Allowed per label and NCCN 2A for use in adults with metastatic or recurrent unresectable HER2+ breast cancer after ≥2 prior anti‑HER2 therapies (≥1 in metastatic setting)	Covered

OpenPayer