Prior authorization and approval durations

Prior authorization is required for drugs in this policy. Initial approvals for oral drugs may be granted for up to 6 months; re-authorizations for oral and injectable drugs may be approved for up to 12 months if drug-specific coverage criteria are met and chart notes demonstrate continued clinical benefit.

• Initial authorization: oral drugs — up to 6 months.
• Re-authorization: oral and injectable drugs — may be approved up to 12 months with documentation of continued benefit.

Check pharmacy vs medical benefit assignment

Determine benefit assignment before submitting authorization: some HER2-targeted small-molecule agents are managed under the pharmacy benefit while monoclonal antibodies, ADCs, and most trastuzumab products are managed under the medical benefit; prior authorization pathways follow that assignment.

• Pharmacy benefit examples: Hernexeos (zongertinib), Hyrnuo (sevabertinib), lapatinib, neratinib, tucatinib.
• Medical benefit examples: Enhertu, trastuzumab products, ado-trastuzumab emtansine, pertuzumab and pertuzumab-containing products.

Confirm prior therapy and trial-consistent dosing

For agents with trial-based eligibility (eg, ado‑trastuzumab emtansine), prior authorization must document prior therapies and dosing consistent with trial criteria and labeling — specifically prior trastuzumab and a taxane and planned dosing of ado‑trastuzumab emtansine 3.6 mg/kg IV every 3 weeks when indicated.

• Confirm prior exposure to trastuzumab and a taxane as required by EMILIA trial-derived criteria.
• Document planned dosing schedule (ado‑trastuzumab emtansine 3.6 mg/kg IV q3w) when applicable.

Prior authorization required for HER2-targeted agents

Obtain prior authorization for all HER2-targeted therapies in this policy; coverage changes, biosimilar/ preferred-product designations, and quantity limits (eg, for tucatinib) require approvals consistent with the policy criteria.

• Submit authorization requests consistent with the most recent product preference and quantity-limit updates.
• Non-formulary exception requests follow standard review (see exception review block).

Prior authorization and non‑formulary exception review

Certain non‑preferred trastuzumab products and other HER2 agents require prior authorization and may require documentation of trials with preferred products or a non‑formulary exception; non‑formulary exception approvals may be granted for up to 12 months and prescriptions must follow FDA dosing/administration.

• Non-preferred trastuzumab products: require trial of all preferred trastuzumab products prior to approval.
• Non‑formulary exceptions: can be approved up to 12 months; must follow FDA dosing/administration information.

Initial authorization period — oral drugs

Note the updated initial authorization period: initial approvals for oral drugs in this policy were changed from 3 months to 6 months; use this period when requesting first-time authorizations for oral agents.

• Apply 6-month initial approval window for oral HER2-targeted agents listed in the policy.

Formulation sequencing — Herceptin Hylecta requirements

Herceptin Hylecta (subcutaneous trastuzumab + hyaluronidase) is only authorized after documentation of inadequate response or intolerance to listed IV trastuzumab biosimilars, except when difficult venous access is documented; Hylecta must be administered by a healthcare professional (subcutaneous administration).

• Require documentation of inadequate response or intolerance to IV biosimilars (Kanjinti, Ogivri, Trazimera) before approving Hylecta, unless difficult venous access is shown.
• Hylecta is administered subcutaneously and must be given by a health-care professional.

Document sequencing — concurrent vs sequential trastuzumab

When trastuzumab is given in the adjuvant setting, evidence favors concurrent administration with paclitaxel over sequential administration for improved disease‑free survival in at least one trial; include sequencing rationale in the authorization documentation when relevant.

• Document whether trastuzumab will be given concurrently with chemotherapy (preferred per NCCTG N9831 interim results) or sequentially, and justify deviations from concurrent use.

Therapy sequencing — prior-agent context for ado‑trastuzumab emtansine

For agents used after prior HER2 therapy (eg, ado‑trastuzumab emtansine), ensure authorization documentation reflects the appropriate prior-agent context — EMILIA supported ado‑trastuzumab emtansine after prior trastuzumab and a taxane; cite prior regimen and timing in the request.

• Specify prior trastuzumab and taxane exposure and whether the prior treatment was for metastatic disease or recurrence within adjuvant settings.
• Reference the comparator/regimen used in pivotal trials (eg, lapatinib + capecitabine in EMILIA) when relevant to line of therapy.

Trial of preferred trastuzumab products required

Before authorizing a non‑preferred trastuzumab product, the provider must document trial and inadequate response or intolerance to all preferred trastuzumab products; failure to document such trials may result in denial.

• Preferred-product examples referenced in history include Kanjinti and Trazimera when designated preferred.
• If preferred agents were not tried, request should include rationale or a non‑formulary exception.

Preferred-product trial — detailed documentation required

If requesting coverage for a non‑preferred trastuzumab product, include documentation that all preferred trastuzumab products were tried and failed; the policy requires trial‑with of preferred agents prior to approval of non‑preferred products.

• List dates and reasons for discontinuation/intolerance of each preferred trastuzumab product.
• Attach infusion/administration records or prior authorization decisions showing prior use of preferred agents.

Historical preferred/non‑preferred biosimilar rules

Historically and currently the policy designates certain trastuzumab biosimilars as preferred while others are non‑preferred; verify the current preferred/non‑preferred status in the policy history and include evidence of trial/failure per that formulary placement when requesting non‑preferred agents.

• History notes document changes in preferred status (eg, Ogivri moved between non‑preferred and preferred).
• Provider requests must reflect the most recent designation in the policy.

Required clinical documentation — general medical records

Submit medical records to support medical necessity: include office visit notes with diagnosis, relevant history, physical exam, medication history, and any other records demonstrating that coverage criteria are met.

• Include clinical notes that state the indication, prior therapies, treatment response, and plan.
• Attach documentation of requests for trial of preferred agents when applicable.

HER2 status and cardiac monitoring documentation

Provide HER2 testing documentation performed by a laboratory with demonstrated proficiency (IHC or FISH) and baseline and periodic left ventricular ejection fraction (LVEF) measurements within the treating institution's normal range; continued therapy depends on absence of an unacceptable LVEF decline (eg, >15% from baseline).

• Attach HER2 assay results (HercepTest, Pathway HER2/neu, PathVysion, or HER2 FISH pharmDx) and laboratory information.
• Provide baseline LVEF and subsequent monitoring values (eg, 3, 6, 12 months) or explain monitoring plan.

HER2 status and prior therapy documentation — gastric cancer

For metastatic gastric/gastroesophageal cancer, include documentation of HER2‑positive status and prior chemotherapy regimen details to match the Phase III trial population used to support coverage.

• Supply pathology/staining reports confirming HER2 overexpression/amplification and chemotherapy history (eg, platinum + fluoropyrimidine).

Non‑formulary exception timing and FDA dosing adherence

Non‑formulary exception requests may be approved for up to 12 months; include rationale for exception and confirm that prescriptions follow the product's FDA dosing and administration prescribing information.

• State the reason preferred agents are not appropriate (intolerance, lack of efficacy, access issues).
• Provide planned dosing consistent with FDA labeling.

Dosage and exception documentation

When requesting approval for off‑label dosing or durations, document adherence to the product's FDA dosing/administration information; non‑formulary exception reviews that deviate from labeled dosing require justification and are limited to up to 12 months if approved.

• Include prescribing information excerpts or peer‑reviewed rationale when deviating from labeled dosing.
• Non‑formulary exceptions follow the 12‑month maximum approval guidance.

Review authorizations — up to 12 months

Authorization reviews for drugs in this policy may be approved for up to 12 months on review when criteria are met; ensure chart notes document ongoing positive clinical response to support re‑authorization.

• For re‑authorization requests, include interval assessment notes documenting response, adverse events, and ongoing plan.

Denial risk — missing documented HER2 alteration or prior therapy

Authorizations may be denied if the diagnosis does not document the indicated HER2 alteration or if stated prior therapy requirements in the policy are not met; include pathology or molecular reports and prior treatment records to avoid denial.

• Examples: absence of documented HER2 TKD activating mutation for NSCLC agents or missing prior systemic therapy when required.
• Attach mutation report, pathology, and prior oncology treatment records.

Triggers for potential denial

Potential denial triggers include HER2 testing performed by a lab without demonstrated proficiency, missing baseline or periodic LVEF monitoring, or use of ado‑trastuzumab emtansine in pregnancy — provide testing facility information, cardiac monitoring records, and pregnancy status as applicable.

• Confirm HER2 testing was performed by a proficient facility and attach assay report.
• Provide baseline LVEF and periodic monitoring values; if missing, explain monitoring plan.
• For ado‑trastuzumab emtansine, confirm the patient is not pregnant and document contraception counseling when relevant.

Small node‑negative tumors exclusion — adjuvant trastuzumab limits

Adjuvant trastuzumab trials excluded individuals with small (<1 cm) node‑negative tumors; absence of evidence of benefit for that subgroup may lead to denial for adjuvant use in tumors <1 cm — document tumor size and nodal status clearly when requesting adjuvant trastuzumab.

• If tumor is <1 cm and node‑negative, include justification or evidence supporting use if requesting coverage.

Denial risk — failure to trial preferred trastuzumab products

Failure to document trial and inadequate response or intolerance to preferred trastuzumab products before requesting non‑preferred agents may result in denial or a requirement to complete step therapy; include prior trial records to support requests for non‑preferred trastuzumab products.

• Document dates, doses, response, and reasons for discontinuation for each preferred trastuzumab product tried.
• If unable to trial preferred agents, provide clinical rationale for exception.

Formulary trial and exception limits — step therapy enforcement

Step‑therapy enforcement: non‑preferred trastuzumab products require trial of all preferred trastuzumab products before coverage is approved; if the required trials are not documented, requests will be denied or returned for step‑therapy completion.

• Preferred‑first enforcement applies to trastuzumab biosimilars and certain reference products per policy history.
• Include prior authorization approvals or infusion records demonstrating preferred product use and failure.

Confirm member benefit plan limits

Coverage is subject to the member's benefit plan limits and conditions; verify member benefits and consult the member benefit booklet or customer service — services not covered under the member's plan may be denied regardless of medical necessity.

• Confirm whether the policy applies to the member (note: policy does not apply to Medicare Advantage).
• Contact member services or check benefit booklet for plan‑level coverage restrictions.

Herceptin Hylecta subcutaneous administration and professional administration requirement

Herceptin Hylecta is administered subcutaneously and must be administered by a healthcare professional; prior authorization requirements for Hylecta follow the medical benefit rules when applicable.

Administration site depends on benefit assignment

Administration site depends on benefit assignment: pharmacy-managed oral agents are dispensed for outpatient use, while medical benefit monoclonal antibodies/ADCs are administered in medical settings (infusion center, office, or hospital outpatient).

IV infusions administration and facility considerations

Intravenous trastuzumab products and ado-trastuzumab emtansine are administered as IV infusions; ensure the facility or institutional setting is appropriate for IV biologic infusions and bill under the medical benefit.

Infusion vs oral agent administration notes

Infusions (IV biologics and ADCs) should be distinguished from oral agents for administration and billing; follow the product labeling for route of administration and benefit assignment when documenting site of care.

Coverage under medical benefit and member plan limits

Coverage for medical benefit‑managed agents is subject to the member's benefit plan limits and any site-of-care restrictions in the member's benefit booklet; verify coverage prior to service.

Herceptin (trastuzumab) IV biosimilars preferred first-line; Herceptin Hylecta use after inadequate response/intolerance

IV trastuzumab biosimilars (eg, Kanjinti, Ogivri, Trazimera) are preferred first-line under the medical benefit; Herceptin Hylecta (subcutaneous) may be used only after inadequate response or intolerance to listed IV biosimilars or for difficult venous access.

Multiple trastuzumab biosimilars listed under medical benefit management

Multiple trastuzumab biosimilars and reference products are listed and managed under the medical benefit; confirm the current preferred list when requesting authorization.

Updated trastuzumab product moved from non-preferred to preferred

Policy history shows Ogivri was updated from non-preferred to preferred; always verify current product status in the policy history before submitting requests for non-preferred agents.

Updated trastuzumab products designated non-preferred requiring trial of preferred agents

Some trastuzumab products were updated to non-preferred status requiring documented trials of all preferred trastuzumab products prior to coverage of the non-preferred product.

Product status updated from non-preferred to preferred

Policy history records show product status changes where agents moved from non-preferred to preferred; verify these historical changes when constructing authorization rationale.

Added a second-line trastuzumab biosimilar product

A second-line trastuzumab biosimilar (Hercessi) was added to the policy as a later-line product; include sequencing rationale if requesting second-line biosimilars.

Trastuzumab reference products — preferred and non-preferred designations updated historically

Preferred and non-preferred designations for trastuzumab reference products and biosimilars have been updated over time; check the policy history to ensure correct billing and step‑therapy documentation.

Coverage under the medical benefit and subject to member benefit plan limits

Coverage under the medical benefit is subject to the member's benefit plan limits and conditions; verify the member's booklet for any applicable restrictions prior to service.

Coverage subject to member benefit plan limits and conditions

All coverage and prior authorization determinations remain subject to the member's benefit plan limits and conditions; services may be denied if not covered by the member's benefit booklet.