ModifiedPremera BluecrossPolicy N/A

HER2 Inhibitors (pharmacy coverage)

Defines medical necessity, coverage criteria, documentation, and coding for HER2-targeted oral and injectable oncology drugs for members receiving therapy for HER2-positive cancers.

Policy Summary

PayerPremera Bluecross

PolicyHER2 Inhibitors (pharmacy coverage)

Policy CodePolicy N/A

Change TypeCoverage and operational updates (Enhertu, Tukysa, biosimilar preferences)

Effective DateApr 1, 2025

Next Review DateApr 1, 2025

Key ActionObtain prior authorization and document HER2 positivity (IHC or FISH) and prior therapies per drug-specific criteria.

SourceLink

POLICY UPDATE CHANGES

Added coverage for Enhertu (fam-trastuzumab deruxtecan-nxki) for adults with unresectable or metastatic HER2-low breast cancer and unresectable or metastatic non-small cell lung cancer.

Updated coverage criteria for Tukysa (tucatinib) when used with trastuzumab for RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer and added a quantity limit requirement for Tukysa in colorectal cancer criteria.

Added Hercessi (trastuzumab-strf) and Hercessi listed among approved trastuzumab biosimilars.

Clarified that non-formulary exception review authorizations for all drugs listed in this policy may be approved up to 12 months and that medications are subject to FDA dosing and administration prescribing information.

Moved Trazimera to second-line (non-preferred) agent effective January 1, 2024 after provider notification.

multipleHER2-targeted drugs addressed

1 yearNerlynx max duration

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600 mg/dayTukysa dose limit

240 mg/dayNerlynx dose limit

12 monthsMax non-formulary auth

Coverage Criteria for HER2-targeted Therapies

Lapatinib (generic) / Tykerb (lapatinib)

Covered when ALL of the following are met

Lapatinib with capecitabine: Individual has advanced or metastatic HER2-positive breast cancer AND has received prior therapy including an anthracycline, a taxane, and trastuzumab and progressed on trastuzumab

Generic lapatinib considered medically necessary in combination with capecitabine after progression on prior trastuzumab-containing regimens; Tykerb requires trial of generic lapatinib first or documentation of inadequate response/intolerance to generic lapatinib

Neratinib (Nerlynx)

Covered when ALL of the following are met

Neratinib extended adjuvant: Individual aged >=18 AND diagnosis stage I-III HER2-overexpressing or -amplified breast cancer AND neratinib used as extended adjuvant following completion of adjuvant trastuzumab-based therapy240 mg/day; maximum duration 1 year

Dose limit 240 mg daily; total duration limited to 12 months for extended adjuvant use per ExteNET trial

Neratinib metastatic combination: Individual aged >=18 AND diagnosis stage III or IV HER2-overexpressing or -amplified breast cancer AND has received two or more prior anti-HER2 regimens in the metastatic setting AND neratinib is used in combination with capecitabine

Metastatic combination use requirement

Tucatinib (Tukysa)

Covered when ALL of the following are met

Tucatinib for metastatic HER2-positive breast cancer: Individual aged >=18 AND has received one or more anti-HER2 regimens in the metastatic setting AND tucatinib is used in combination with trastuzumab and capecitabine600 mg/day (300 mg twice daily)

Includes individuals with brain metastases; dose limited to 600 mg/day

Tucatinib for unresectable/metastatic colorectal cancer: Individual aged >=18 AND unresectable or metastatic RAS wild-type, HER2-positive colorectal cancer (IHC/FISH/NGS criteria) AND disease progressed after fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy AND tucatinib is used in combination with trastuzumab600 mg/day (300 mg twice daily)

Quantity limit requirement applied to colorectal cancer indication per policy update

Trastuzumab products and sequencing

Covered when criteria depend on setting and prior trials of preferred products

Preferred trastuzumab biosimilars (Kanjinti or Trazimera): Kanjinti or Trazimera are considered medically necessary for HER2-positive breast cancer in adjuvant, neoadjuvant, and metastatic settings as indicated in trials and labeling

Preferred first-line trastuzumab biosimilars per formulary; used in adjuvant, neoadjuvant, and metastatic regimens

Herceptin Hylecta (subcutaneous) exception: Herceptin Hylecta may be used when the individual has had inadequate response or intolerance to preferred biosimilars, or when difficult venous access is documented

Subcutaneous formulation exception allowed for difficult venous access

Other trastuzumab products after trial/failure: Herceptin, Hercessi, Herzuma, Ogivri, Ontruzant, and other trastuzumab products may be considered medically necessary after adequate trial and failure of Kanjinti or Trazimera

Non-preferred products require documented inadequate response or intolerance to preferred biosimilars; avoid combining trastuzumab with anthracyclines for palliative metastatic gastric therapy

Pertuzumab-containing therapies

Covered when ALL of the following are met

Perjeta (pertuzumab): Pertuzumab used in combination with trastuzumab and a taxane (docetaxel or paclitaxel) for previously untreated HER2-positive breast cancer or recurrent disease in adjuvant, neoadjuvant, or metastatic settings

Pertuzumab is used as part of combination regimens consistent with trial and labeling

Phesgo (pertuzumab + trastuzumab SC): Phesgo may be used in the same combination regimens as pertuzumab plus trastuzumab; switching between IV pertuzumab/trastuzumab and Phesgo is allowed

SC combination product allowing substitution per policy

Antibody-drug conjugates / newer targeted agents

Covered when ALL of the following are met

Kadcyla (ado-trastuzumab emtansine): Individual with unresectable, locally advanced, or metastatic HER2-positive breast cancer who previously received trastuzumab and a taxane and prior treatment for metastatic disease

Single-agent use after specified prior therapy consistent with EMILIA trial (T-DM1 3.6 mg/kg IV every 3 weeks)

Enhertu (fam-trastuzumab deruxtecan-nxki): Considered medically necessary for multiple indications including unresectable/metastatic HER2-positive breast cancer after prior anti-HER2 regimens, select unresectable/metastatic NSCLC with activating HER2 mutations after prior systemic therapy, HER2-positive gastric/GEJ adenocarcinoma after prior trastuzumab-based regimen, and certain HER2-positive solid tumors after prior systemic treatment

Coverage expanded into earlier breast cancer settings and HER2-low indications per DESTINY trials and policy updates

Margenza (margetuximab-cmkb): Metastatic HER2-positive breast cancer in individuals aged >=18 who have received two or more prior anti-HER2 regimens, at least one for metastatic disease, used in combination with chemotherapy

Adjuvant therapy

Covered when ALL of the following are met (reflecting trial inclusion):

Adjuvant trastuzumab general criteria: 1) Pathologically confirmed HER2-positive breast cancer (IHC or FISH). 2) Clinical features consistent with trial populations (node-positive or high-risk node-negative; trials excluded tumors <1 cm). 3) Intended use as adjunct to adjuvant chemotherapy per regimens studied.see node text

Derived from randomized adjuvant trials (BCIRG006, HERA, NCCTG N9831, NSABP B31, FinHer).

Neoadjuvant therapy

Covered when ALL of the following are met:

Neoadjuvant trastuzumab criteria: 1) HER2-positive, operable stage II–IIIA breast cancer undergoing neoadjuvant chemotherapy. 2) Trastuzumab initiated concurrent with chemotherapy as in trials. 3) Intended goal includes improving pathologic complete response and reducing recurrence risk.see node text

Based on randomized and single-arm neoadjuvant data showing increased pCR with trastuzumab.

Metastatic breast cancer

Covered when ALL of the following are met:

Metastatic breast cancer criteria: 1) HER2-positive metastatic or locally advanced breast cancer. 2) Use may be as single agent or in combination with chemotherapy or hormonal therapy as supported by trials (including trastuzumab with taxane, capecitabine, or aromatase inhibitor). 3) Consider continued trastuzumab beyond progression per trial evidence (e.g., capecitabine + trastuzumab vs capecitabine alone showed longer time to progression).see node text

Derived from pivotal metastatic trials and combination studies.

Gastric cancer

Covered when ALL of the following are met:

Gastric/gastroesophageal adenocarcinoma criteria: 1) HER2-positive locally advanced, recurrent, or metastatic gastric or gastroesophageal junction adenocarcinoma. 2) Use in combination with chemotherapy as in the Phase III ToGA trial (trastuzumab every 3 weeks for up to 6 cycles or until progression).see node text

ToGA trial demonstrated median overall survival benefit (13.8 vs 11.1 months) with trastuzumab.

Covered Indications

Covered when matching the populations and indications supported by clinical trial evidence:

Trastuzumab for breast cancer: Use for HER2-positive primary or metastatic breast cancer supported by randomized trials showing survival benefit; requires documented HER2 overexpression (IHC 3+ or IHC 2+ with FISH confirmation).HER2 overexpression (IHC 3+ or IHC 2+ with FISH)

See breast cancer trial evidence summarized in policy

Trastuzumab for gastroesophageal/gastric adenocarcinoma: Use in HER2-positive advanced or metastatic gastroesophageal/gastric adenocarcinoma in combination with chemotherapy as per ToGA trial showing median OS benefit (13.8 vs 11.1 months); requires documented HER2 positivity.HER2 positive per trial testing

Approximately 22.1% of screened gastric tumors were HER2-positive in the ToGA trial

Ado-trastuzumab emtansine (Kadcyla): Use in unresectable, locally advanced or metastatic HER2-positive breast cancer previously treated with trastuzumab and a taxane, consistent with EMILIA trial showing improved PFS and OS versus lapatinib plus capecitabine.

Coverage updates and high-level criteria

Policy updates and coverage decisions reflected in this section:

Enhertu approvals: Enhertu (fam-trastuzumab deruxtecan-nxki) approvals expanded to include unresectable or metastatic HER2-low breast cancer and certain NSCLC indications; coverage also expanded into earlier breast cancer settings (second-line and adjuvant/neoadjuvant) based on DESTINY trials.

2022 and subsequent updates added these indications

Tukysa updates: Coverage criteria for Tukysa (tucatinib) in combination with trastuzumab for RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer were updated and a quantity limit requirement was added to colorectal cancer criteria.

2023–2024 policy updates

Trastuzumab biosimilar changes: Multiple trastuzumab biosimilars were added/updated (Hercessi, Kanjinti, Trazimera, Ontruzant, Herzuma, Ogivri); formulary preference changes occurred (e.g., movement of Trazimera to second-line in 2024 and preferred status changes effective 2025).

Documented in policy history

All indications for drugs listed in this policy that are not explicitly described in the drug-specific coverage criteria are considered investigational. Providers should rely on the individual agent sections of this policy to determine whether a proposed use is supported by trial evidence and the policy's medical necessity requirements.

Randomized adjuvant trastuzumab trials excluded individuals with small, node‑negative tumors (<1 cm). Therefore there is no evidence of benefit for adjuvant trastuzumab in this subgroup and adjuvant use for tumors <1 cm node‑negative is not supported by the trial populations.

Available clinical data do not support use of trastuzumab for several non‑breast tumor types. Uncontrolled pilot or small trials reported feasibility issues or low activity for prostate cancer, salivary gland tumors, ovarian/peritoneal carcinoma, and phase II reports in non‑small cell lung cancer showed no improvement with added trastuzumab; these tumor types lack supportive randomized evidence and are not recommended indications in this policy.

Authorization and clinical use must follow the product's FDA dosing and administration prescribing information. For non‑formulary exception reviews, the policy clarifies that approvals may be authorized for up to 12 months. Initial and reauthorization lengths for oral and injectable agents follow drug‑specific criteria as described elsewhere in the policy.

This medical policy does not apply to Medicare Advantage; member benefit limitations and plan applicability should be confirmed by consulting the member benefit booklet or customer service.

The use of trastuzumab products concurrently with anthracyclines is not recommended for palliative treatment of metastatic gastric or gastroesophageal junction adenocarcinoma; the policy explicitly cautions against combining trastuzumab with anthracyclines in that palliative setting.

Pilot and uncontrolled studies of trastuzumab in prostate cancer demonstrated poor feasibility (very low prevalence of required HER2 expression on screening) and limited efficacy; as a result, trastuzumab use in prostate cancer is unsupported by the evidence summarized in this policy.

Single‑agent trastuzumab showed poor clinical activity in advanced hormone‑refractory prostate cancer and low response rates were observed in small studies of salivary gland and ovarian/peritoneal cancers. Phase II reports in non‑small cell lung cancer did not demonstrate improved outcomes with addition of trastuzumab. These findings indicate lack of efficacy for these single‑agent or small‑study uses.

Initial Therapy / Line-specific Requirements

Initial therapy rules

Initial therapy requirements for specific agents

Lapatinib initial: Generic lapatinib is considered medically necessary in combination regimens (e.g., with capecitabine or letrozole) for metastatic HER2-positive disease after prior anthracycline, taxane, and trastuzumab exposure; Tykerb requires trial of generic lapatinib first or documentation of inadequate response/intolerance to generic lapatinibTykerb dose limit 1500 mg/day

Oral agent initial sequencing and dose limit per policy

Pertuzumab/Phesgo initial: Perjeta (pertuzumab) or Phesgo may be used in combination with trastuzumab and a taxane (docetaxel or paclitaxel) for previously untreated or recurrent HER2-positive breast cancer per trial regimens

Combination with chemotherapy required in initial (first-line) settings

Initial therapy — metastatic

Metastatic/first-line combinations and hormone-combination evidence:

Re-authorization and Continuation Requirements

Re-authorization

Re-authorization conditions

Re-authorization: Reauthorization may be approved up to 12 months for injectable drugs and for oral drugs when drug-specific criteria are met and chart notes document continued clinical benefit; initial oral authorizations typically shorter (e.g., up to 3 months)

Non-formulary exception and injectable approvals may be authorized up to 12 months per policy

Adjuvant continuation therapy

Continuation/maintenance considerations reflect trial durations and sequencing:

Adjuvant duration and sequencing: 1) Standard adjuvant trastuzumab duration supported by trials and meta-analysis is 1 year; 2 years was not more effective and had more adverse events; shorter durations (6 months) were inferior in some trials. 2) Concurrent trastuzumab with taxane showed longer DFS than sequential administration in NCCTG N9831 interim results; sequencing may affect outcomes and cardiac risk profiles.see node text

Step Therapy and Sequencing Rules

Step	Requirement	Failure criteria / notes
1
Trial and documented inadequate response or intolerance to preferred trastuzumab biosimilars (Kanjinti or Trazimera) is required before coverage of alternative trastuzumab products (e.g., Herceptin, Hercessi, Herzuma, Ogivri, Ontruzant)
Medical record must document trial and failure (or intolerance); exception for Herceptin Hylecta when difficult venous access is documented

Step	Evidence point	Clinical implication
1
NCCTG N9831 six-year interim results demonstrated longer disease-free survival (DFS) with concurrent trastuzumab administered with paclitaxel versus sequential trastuzumab
Sequencing (concurrent vs sequential) may affect outcomes and should be considered when matching prior trial regimens during authorization

Step	Prior exposure / progression requirement	Supporting trial population
1
Documentation of prior trastuzumab and taxane exposure (and progression when applicable) is required for agents studied after trastuzumab failure (e.g., ado-trastuzumab emtansine) or for adjuvant-to-extended adjuvant sequences (neratinib)
EMILIA enrolled patients previously treated with trastuzumab and a taxane; lapatinib+capecitabine trials enrolled patients progressing after anthracyclines, taxanes, and trastuzumab; ExteNET required completion of trastuzumab-based adjuvant therapy

Step	Formulary sequencing change	Effective date / implication
2
Trazimera (trastuzumab-qyyp) has been moved to a second-line (non-preferred) position in the treatment sequence
Change effective January 1, 2024 after provider notification; implies preferred biosimilars should be trialed first for step-therapy

Step	Requirement	Examples / supporting history
1
Adequate trial and documented failure of preferred trastuzumab products (Kanjinti or Trazimera) required before coverage of non-preferred trastuzumab agents
Policy history and current criteria updated to require trial/failure with preferred agents; documentation of intolerance or inadequate response must be provided (history entries 07/01/22, 01/01/25 reference requirement and coding updates)

Billing Codes and Monitoring Requirements

HCPCS codes listedHCPCS

J3590	Unclassified biologics (use to report: Hercessi)
J9306	Injection, pertuzumab (Perjeta), mg
J9316	Injection, pertuzumab, trastuzumab, and hyaluronidase-zzxf; (Phesgo) per 10 mg
J9353	Injection, margetuximab-cmkb, (Margenza) 5 mg
J9354	Injection; ado-trastuzumab emtansine (Kadcyla), mg
J9355	Injection, trastuzumab; excludes biosimilar; (Herceptin) 10 mg
J9356	Injection, trastuzumab, (Herceptin Hylecta) 1Omg and hyaluronidase-( oysk)
J9358	Injection; fam-trastuzumab deruxtecan-nxki (Enhertu), mg
Q5112	Injection, trastuzumab-dttb, biosimilar; (Ontruzant), 10 mg
Q5113	Injection, trastuzumab-pkrk; biosimilar; (Herzuma), 10 mg

1–10 of 14

1/2

HCPCS and historical billing codes referencedHCPCS

J9306	HCPCS code added 1/1/14 (referenced in history)
J9354	HCPCS code added effective 1/1/16 (referenced in history)
J9356	HCPCS code added 7/1/19 (referenced in history)
Q5112	HCPCS code added 7/1/19 (referenced in history)
Q5113	HCPCS code added 7/1/19 (referenced in history)
Q5114	HCPCS code added 7/1/19 (referenced in history)
Q5116	HCPCS code added 10/1/19 (referenced in history)
Q5117	HCPCS code added 10/1/19 (referenced in history)
J9358	HCPCS code added (referenced in history)
J3590	HCPCS code referenced multiple times in history (added/removed)

1–10 of 13

1/2

Left ventricular ejection fraction monitoring — inv-23

When to measure LVEFMeasure left ventricular ejection fraction before initiating trastuzumab and periodically during therapy (examples: at ~3, 6, and 12 months)

Acceptable baselineBaseline LVEF should be within the treating institution's normal range prior to starting trastuzumab

Unacceptable decline thresholdAvoid continued therapy if there is an unacceptable decrease (for example, >15% from baseline LVEF)

Monitoring frequency examplePeriodic monitoring examples cited: at 3 months, 6 months, and 12 months after initiation

DocumentationDocument baseline and ongoing cardiac function (LVEF) in the medical record to support ongoing therapy

Prior Authorization, Documentation, and Operational Steps

Prior Authorization

Prior Authorization Required and Approval Durations

Prior authorization is required for agents listed in this policy. Approvals are granted consistent with drug-specific coverage criteria and product FDA dosing/administration instructions. Initial and reauthorization approval durations follow the formulary and drug type: oral drug reviews may be approved for up to 3 months when not part of a non-formulary exception; injectable drugs and non-formulary exception reviews may be approved up to 12 months. Reauthorization may be granted when chart notes document continued clinical benefit and medical necessity criteria are met.

Prior authorization required per drug-specific coverage criteria
Initial approvals: oral drugs — typically up to 3 months (unless non-formulary exception)
Initial approvals: injectable drugs — may be approved up to 12 months
Non-formulary exception review authorizations may be approved up to 12 months
Reauthorization contingent on documentation of ongoing clinical response and adherence to FDA dosing

Prior Authorization

Indication and Biomarker Confirmation

Clinical Background and Evidence Summary

HER2 (ERBB2) is a transmembrane tyrosine kinase receptor whose amplification or overexpression drives tumor growth in a subset of cancers, most notably breast cancer. HER2‑targeted agents — including monoclonal antibodies, antibody–drug conjugates, and small‑molecule tyrosine kinase inhibitors — act by blocking HER2 signaling and are used in adjuvant, neoadjuvant, and metastatic settings when tumor HER2 overexpression or amplification is documented.

Definitions and Drug Descriptions

HER2 overexpression / amplification — inv-45

DefinitionDetermination of HER2 overexpression/amplification is by immunohistochemistry (IHC) and in situ hybridization (FISH/ISH) assays performed by proficiency-tested laboratories

Testing requirementDocument HER2-positivity (IHC or FISH) prior to trastuzumab or other anti-HER2 therapy

Assay examplesCommercially available assays include IHC tests and FISH assays such as PathVysion and HER2 FISH pharmDx

Interpretation noteUse results from reliable, proficiency-tested laboratories; unreliable assay performance can lead to incorrect selection

HER2 (HERZ in document) — inv-46

TermHER2 (also rendered as HERZ in this document) = human epidermal growth factor receptor 2, a transmembrane tyrosine kinase encoded on chromosome 17q

Quantity Limits and Dose Constraints

Neratinib (Nerlynx) — inv-65

Daily dose limitNeratinib (Nerlynx) dose limited to 240 mg per day (six tablets)

Extended adjuvant durationUsed as extended adjuvant therapy for up to 1 year following completion of trastuzumab‑based adjuvant therapy

Metastatic combination useIn metastatic setting, neratinib may be used in combination with capecitabine after two or more prior anti‑HER2 regimens

Tucatinib (Tukysa) — inv-66

Daily dose limitTucatinib (Tukysa) dose limited to 600 mg per day (300 mg twice daily)

Quantity limit updateA quantity‑limit requirement was added to Tukysa in the colorectal cancer coverage criteria (policy history 2024)

Administration Setting Considerations

Billing Rule

Specify infusion route and site-of-care for trastuzumab products

Injectable trastuzumab products are administered via intravenous infusion; Phesgo is a subcutaneous formulation; indicate site-of-care and administration route on the request to ensure appropriate coding and setting.

Specify IV infusion for Herceptin, Kadcyla, Enhertu, etc.; specify SC for Phesgo.
Include planned infusion center or outpatient setting as appropriate.

Note

Trastuzumab Biosimilars and Preference Rules

Note

Policy Revision History and References

2025-01-03formulary_updateLatest

Kanjinti and Trazimera changed to preferred trastuzumab products; Herceptin, Herceptin Hylecta, and Ogivri changed to non-preferred trastuzumab products (effective after 90-day provider notification).

2024-10-01biosimilar_addition

Hercessi (trastuzumab-strf) added as a second-line trastuzumab product and HCPCS code J3590 added to report Hercessi; change approved Sept 10, 2024 and effective Jan 3, 2025 following provider notification.

2024-08-01

Policy Summary

PayerPremera Bluecross

PolicyHER2 Inhibitors (pharmacy coverage)

Policy CodePolicy N/A

Change TypeCoverage and operational updates (Enhertu, Tukysa, biosimilar preferences)

Effective DateApr 1, 2025

Next Review DateApr 1, 2025

Key ActionObtain prior authorization and document HER2 positivity (IHC or FISH) and prior therapies per drug-specific criteria.

SourceLink

On This Page

Margetuximab use requires prior anti-HER2 regimens

Prior trastuzumab and taxane exposure

EMILIA trial: PFS 9.6 vs 6.4 months; OS 30.9 vs 25.1 months

Neratinib (adjuvant): Extended adjuvant neratinib for 12 months after completion of trastuzumab-based adjuvant therapy reduces invasive disease-free survival events at 2 years in early-stage HER2-positive breast cancer per ExteNET trial.Completion of trastuzumab-based adjuvant therapy; neratinib 240 mg daily for 12 months

Dose and duration per trial; used to reduce invasive DFS events

Other indications with limited or negative evidence: Evidence is limited or negative for trastuzumab in prostate, salivary gland, ovarian/peritoneal, non-small cell lung, and other tumors; use generally not supported by randomized data.Depends on tumor type; HER2 overexpression often rare

Small uncontrolled studies mostly negative

Tucatinib (Tukysa) + trastuzumab for colorectal cancer: Use for RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer after progression on fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy; approval based on trials showing ORR ~38% and durable responses with tucatinib 300 mg twice daily plus trastuzumab.RAS wild-type and HER2 positive; prior standard chemotherapy

Combination accelerated approval based on tumor response and durability

Authorization clarifications: Non-formulary exception review authorizations for drugs in this policy may be approved up to 12 months; medications are subject to FDA dosing and administration prescribing information.

Clarified in 2025 update

Metastatic first-line options: Trastuzumab may be used as monotherapy or combined with chemotherapy (taxane, capecitabine, platinum agents) or with hormonal therapy (e.g., anastrozole) in appropriate HER2-positive metastatic disease as supported by randomized trials; combinations demonstrated improved response rates, PFS, and in some trials OS.see node text

Based on pivotal metastatic trials and the Kaufman anastrozole+trastuzumab trial

Initial therapy contexts

Initial or line-specific therapy contexts noted in trials:

Lapatinib + capecitabine context: Lapatinib plus capecitabine was studied in patients with HER2-overexpressing metastatic breast cancer progressing after anthracyclines, taxanes, and trastuzumab and is an option in later-line therapy per trial context (improved time to progression vs capecitabine alone).

Trial evidence supports use after prior trastuzumab

INITIAL THERAPY CRITERIA

Policy history reflects evolving initial therapy criteria: Policy history documents additions and sequencing changes for initial therapy over time (pertuzumab, trastuzumab biosimilars, Enhertu, tucatinib), which affect preferred agents and line-of-therapy requirements.

See history entries for specific dates and formulary preference changes

Derived from HERA, PHARE, NCCTG N9831 and Cochrane meta-analysis; monitor LVEF per labeling

Continuation therapy examples

Continuation/maintenance therapy considerations per trial populations:

Adjuvant neratinib continuation: Neratinib administered for 12 months following completion of trastuzumab-based adjuvant therapy in early-stage HER2-positive breast cancer per ExteNET trial criteria; continued therapy requires documentation of prior adjuvant trastuzumab completionneratinib 240 mg daily for 12 months

Continuation aligned with trial duration and dosing

Prior authorization requests must document the specific indication for therapy (for example: adjuvant, neoadjuvant, metastatic breast cancer, metastatic gastric/gastroesophageal junction cancer, or unresectable/metastatic colorectal cancer) and must confirm tumor HER2 status. Acceptable HER2 documentation includes IHC (3+ positive; 2+ with confirmatory ISH/FISH or amplification by NGS) or other validated testing per coverage criteria. For agents with HER2-low or HER2-ultralow indications, submit the relevant IHC/ISH test results per the drug labeling.

Indication must be clearly stated on the prior authorization request
Document HER2 status: IHC 3+ OR IHC 2+ with FISH/ISH confirmation or NGS amplification where applicable
For HER2-low/ultralow indications, submit supporting IHC/ISH results

Prior Authorization

Prior Authorization Requirement (Agents and Changes)

Certain products and coverage changes specifically require prior authorization. Examples include tucatinib (Tukysa) when used in combination regimens, trastuzumab products (including preferred and non-preferred biosimilars), and antibody–drug conjugates (e.g., Enhertu) where quantity limits or new indications have been added. Providers should confirm any quantity limits or preferred-product sequencing before submission.

Tukysa (tucatinib) in combination regimens — prior authorization and quantity limits apply
Trastuzumab products (preferred and non-preferred) require authorization per sequence and trial/failure rules
Enhertu and other ADCs — prior authorization and indication-specific criteria apply

Documentation Required

Documentation Required for Medical Necessity

Medical record documentation submitted for prior authorization and reauthorization must demonstrate that medical necessity criteria are met. Lack of adequate documentation may result in denial. Records should include baseline and ongoing assessments relevant to toxicity risks (for example, cardiac monitoring for trastuzumab), prior therapy history, and evidence of response or progression to support line-of-therapy claims.

Office visit notes with diagnosis, relevant history, physical exam, and medication history
Documentation of HER2 testing results (IHC and, when applicable, FISH/ISH/NGS confirmation) prior to trastuzumab use
Baseline and ongoing left ventricular ejection fraction (LVEF) or cardiac function documentation when using trastuzumab-containing regimens
Prior treatment dates and agents (e.g., prior trastuzumab, taxane exposure) to support sequencing/line-of-therapy

Note

Benefit Limits, Mandates, and Member Benefit Verification

Coverage is subject to the limits and conditions of the member's benefit plan. State or federal mandates that require coverage of FDA‑approved drugs may supersede this policy. Providers and members must verify benefits and applicable limits; this policy is a guide, and the member contract governs actual coverage decisions.

Consult the member benefit booklet or contact customer service to determine eligibility, benefit limits, and any exclusions
State and federal mandates may supersede policy when applicable
This medical policy does not replace member-specific benefit determinations

Step Therapy

Trastuzumab Ordering, Preferred Product, and Trial/Failure Requirements

Ordering and sequencing rules for trastuzumab products are applied operationally. Preferred trastuzumab biosimilars (effective formulary changes) should be used first-line when indicated; certain trastuzumab products have been moved to preferred or non-preferred positions with trial/failure requirements for non-preferred products. When non-preferred products are requested, prior trial and documented inadequate response or intolerance to preferred agents (e.g., Kanjinti or Trazimera as preferred agents) is required unless an allowed exception (such as difficult venous access) is documented.

Kanjinti and Trazimera designated as preferred trastuzumab products (effective Jan 3, 2025 changes reflected)
Non-preferred trastuzumab products require documented trial/failure of preferred agents prior to approval
Exceptions (e.g., difficult venous access) may allow alternate product use with supporting documentation

Step Therapy

Sequencing and Line‑of‑Therapy Considerations

Sequencing and line-of-therapy considerations must be documented. Some agents were studied and approved in specific lines (for example, lapatinib + capecitabine after progression on trastuzumab; ado-trastuzumab emtansine in individuals previously treated with trastuzumab and a taxane). Prior exposure to standard therapies (trastuzumab, taxanes, anthracyclines where applicable) should be confirmed in the medical record to support use consistent with clinical evidence and approved labeling.

Document prior trastuzumab and taxane exposure when required by the drug's studied population (e.g., ado-trastuzumab emtansine, lapatinib trials)
No single forced step-therapy sequence is mandated by trials, but approvals depend on consistency with evidence and labeling
Provide treatment dates and responses to support line-of-therapy claims

Documentation Required

Required Medical Record Documentation and Operational Steps

Operational notes: submit full clinical records (office notes, diagnostic reports, pathology/lab reports showing HER2 status, prior chemotherapy details, and cardiac monitoring reports) with the prior authorization request. Incomplete submissions — lacking the items above — may be denied. Providers should follow the product's FDA dosing and administration prescribing information for quantity and duration requests.

Include pathology reports with HER2 testing and numeric results (IHC score, FISH/ISH ratio or NGS report)
Include prior treatment records with dates and responses
Include baseline and interval cardiac function assessments where trastuzumab-related cardiotoxicity is a concern
Requests exceeding FDA dosing or standard approval durations may be denied

Biologic roleForms heterodimers with other HER family members and amplifies downstream signaling involved in cell growth, proliferation, migration, adhesion, and survival

PrevalenceHER2 is amplified/overexpressed in approximately 20–30% of breast cancers

Clinical implicationHER2 overexpression/amplification identifies tumors likely to benefit from antibody-mediated HER2-targeted therapies

Ado-trastuzumab emtansine (T-DM1) — inv-47

Agent descriptionAdo-trastuzumab emtansine (T-DM1; Kadcyla) is an antibody–drug conjugate combining trastuzumab with the cytotoxic agent emtansine (DM1)

Safety considerationsAssociated with increases in liver function enzymes; dose modifications based on LFTs are recommended

Cardiac effectsDecreases in left ventricular ejection fraction have been noted; EMILIA trial required LVEF ≥50% for inclusion

Other risksGestational toxicity—avoid use in pregnancy and require effective contraception during and for at least 6 months after treatment

lapatinib (Tykerb) — inv-48

Agent class and actionLapatinib (Tykerb) is an oral small-molecule inhibitor of the intracellular tyrosine kinase domains of EGFR (ErbB1) and HER2 (ErbB2)

Indication contextUsed in combination with capecitabine for advanced/metastatic HER2-overexpressing breast cancer after prior anthracycline, taxane, and trastuzumab therapy

Trial dosing and efficacyIn pivotal trial lapatinib was dosed at 1,250 mg once daily with capecitabine and showed improved time to progression versus capecitabine alone

ado-trastuzumab emtansine (Kadcyla) — inv-49

Agent descriptionAdo-trastuzumab emtansine (Kadcyla, T‑DM1) is an antibody–drug conjugate combining trastuzumab with the cytotoxic emtansine (DM1)

MechanismDelivers cytotoxic payload (DM1) upon internalization into HER2‑expressing cells while retaining trastuzumab activity

Trial contextApproved and used for metastatic HER2‑positive breast cancer after prior trastuzumab and a taxane (EMILIA trial) with dosing of 3.6 mg/kg IV every 3 weeks noted in trials

tucatinib (Tukysa) — inv-50

Agent classTucatinib (Tukysa) is an oral, small-molecule HER2 tyrosine kinase inhibitor

Combination useIndicated in combination with trastuzumab (and capecitabine for breast cancer) and with trastuzumab for HER2‑positive colorectal cancer in the specified settings

Dose limitDose limited to 600 mg per day (300 mg twice daily) in approved regimens

Trastuzumab — inv-51

Agent descriptionTrastuzumab is a humanized monoclonal antibody targeting the extracellular domain of HER2

Regulatory approvalsFDA‑approved for HER2‑positive breast cancer in adjuvant and metastatic settings (initial approval 1998 with subsequent adjuvant approvals)

Formulations and biosimilarsAvailable as IV and SC formulations; multiple biosimilars and combination SC products (e.g., Phesgo) are referenced in the policy

Enhertu (fam-trastuzumab deruxtecan-nxki) — inv-52

Agent descriptionEnhertu (fam‑trastuzumab deruxtecan‑nxki) is a HER2‑targeting antibody–drug conjugate

Expanded approvalsApprovals expanded into earlier breast cancer lines (second-line and adjuvant/neoadjuvant), HER2‑low breast cancer, and certain non‑small cell lung cancers based on DESTINY trials

Policy inclusionEnhertu coverage was added for unresectable or metastatic HER2‑low breast cancer and for certain NSCLC; criteria updated in 2022–2024 policy updates

Combination regimensUsed in combination with trastuzumab (and capecitabine for breast cancer) per approved indications

Tukysa (tucatinib) — inv-67

Policy changeA quantity limit requirement was added for Tukysa (tucatinib) in the colorectal cancer coverage criteria (2024 update)

ImplicationRequests for Tukysa in this indication may be subject to quantity limits and prior authorization per the policy

ReferenceDocumented in 2024 policy update and history entries

neratinib (Nerlynx) — inv-68

Daily doseNeratinib (Nerlynx) 240 mg per day

Formulation noteDose described as six 40‑mg tablets/day in policy language

Use contextUsed for extended adjuvant therapy up to 12 months following trastuzumab‑based adjuvant therapy

lapatinib (Tykerb) — inv-69

Daily dose limit (historical policy)Lapatinib (Tykerb) dose limit noted as 1500 mg per day in policy history and coverage language

Trial dosingIn the pivotal trial lapatinib dosing used was 1,250 mg once daily with capecitabine; policy documents impose a 1,500 mg/day limit for Tykerb

Sequencing noteGeneric lapatinib is preferred first; Tykerb may require trial and inadequate response or intolerance to generic lapatinib

Enhertu coverage criteria updated to include treatment of certain unresectable or metastatic solid tumors (approved July 9, 2024).

2024-04-01quantity_limit_correction

Minor correction to add a quantity limit requirement for Tukysa (tucatinib) in the colorectal cancer coverage criteria (approved Mar 25, 2024).

2023-09-01formulary_change

Trazimera moved to second-line (non-preferred) trastuzumab agent effective January 1, 2024 following provider notification; decision recorded Sept 1, 2023.

2023-06-01coverage_addition

Coverage criteria added for Tukysa (tucatinib) with trastuzumab for RAS wild-type, HER2-positive unresectable or metastatic colorectal cancer after progression on standard chemotherapy (approved 9, 2023).

2022-10-01coverage_addition

Enhertu added for adults with unresectable or metastatic HER2-low breast cancer and unresectable or metastatic non-small cell lung cancer (approved Sept 13, 2022).

2022-07-01preferred_product_update

Ogivri moved to preferred trastuzumab product and coverage criteria for several non-preferred products updated to require trial and failure with preferred products (approved June 14, 2022).

2021-04-01coding_update

Added HCPCS code J3590 and removed previously referenced codes as part of updates effective April 1, 2021; no changes to policy statements in annual review (approved Dec 2, 2021).

2020-07-01criteria_addition

Added criteria for Nerlynx (neratinib) for advanced/metastatic breast cancer and Tukysa (tucatinib) for HER2-positive breast cancer; added J9358 and removed J3590 (approved June 9, 2020).

2020-03-01drug_addition_and_limits

Generic lapatinib added with same covered indications as Tykerb and Tykerb updated to require trial of generic lapatinib first with a dose limit of 1,500 mg/day (approved Feb 9, 2021 entry referencing Mar 1, 2021 changes).

2020-01-01biosimilar_addition

Trazimera added as first-line with Herceptin and initial Enhertu criteria added in early 2020 entries (effective Apr 3, 2020 and Feb 1, 2020 approvals).