How to appeal a Highmark cancer treatments denial

The framework that applies to your appeal

Federal law gives you the right to a full and fair internal appeal, then an external review by an independent third party.

Highmark-specific note: Operates BCBS in PA (western), WV, DE, NY (western). Owns Allegheny Health Network.

What Highmark's policy requires for cancer treatments

Cited policy: BCBS Enhertu (Trastuzumab Deruxtecan) for HER2-Low and HER2-Ultra-Low Breast Cancer

HR+/HER2-low (IHC 1+ or IHC 2+/FISH-) or HR+/HER2-ultra-low (IHC 0 with membrane staining per DESTINY-Breast06 criteria) MBC. Prior endocrine therapy + CDK4/6 inhibitor in HR+. ≥1 prior chemotherapy in MBC setting OR rapid recurrence (DESTINY-Breast06 allows treatment-naive MBC if endocrine-resistant). 5.4 mg/kg IV q3wk. Pneumonitis monitoring per FDA REMS. Hematologist-oncologist Rx.

How Highmark denies cancer treatments — and how to counter it

Where Highmark pushes back: 1) HER2-low not FDA-recognized (outdated); 2) Try Trodelvy or chemotherapy first; 3) HER2 IHC 0 with staining 'too low' for Enhertu; 4) Dose adjustment for prior anthracycline / cumulative cardiotoxicity.

Counter-arguments that hold up: DESTINY-Breast04 (Modi NEJM 2022;387:9) — T-DXd HER2-low MBC: PFS 9.9 vs 5.1 mo, OS 23.4 vs 16.8 mo (HR 0.64). FDA Aug 5, 2022 — HER2-low BC indication. DESTINY-Breast06 (Curigliano Nat Med 2024) — expanded to HER2-ultra-low (IHC 0 with staining); FDA Apr 5, 2024. NCCN Breast v2.2024 Cat 1 for HER2-low MBC post-CDK4/6. Ki-67, prior anthracycline cumulative dose, and ECHO ≥50% per Enhertu REMS — cardiac monitoring required, not contraindication. Trodelvy (Trop-2 ADC) is sequential or subsequent — not a prerequisite per DESTINY-Breast04 design.

What Highmark typically denies for cancer treatments

Across Highmark's commercial and Medicare books, denials cluster around a small number of patterns. For cancer treatments, expect:

• Prior auth on biologics
• PA on advanced imaging
• OON balance bills

Treatments most often denied in this category

These are the cancer treatments treatments most often flagged for prior auth, step therapy, or medical necessity review:

• Checkpoint inhibitor
• CAR-T
• Targeted oral
• ADC
• Proton therapy
• PET imaging

How to submit the appeal to Highmark

1. Read the denial letter — note the exact denial reason code and the appeal deadline (180 days from the date on the letter).
2. Gather supporting documentation: physician letter of medical necessity, relevant clinical notes, peer-reviewed citations supporting the treatment for your indication, and the policy or coverage document Highmark cited in the denial.
3. File the appeal through Highmark's portal (members: https://www.highmark.com ; providers: https://www.highmark.com/provider). Standard decision returns within 30 days; expedited urgent appeals return within 72 hours.
4. If denied again, request external review by an independent reviewer within 4 months of the final internal denial. In PA, the state insurance department coordinates external review for fully-insured plans; ERISA self-funded plans use a federal external review through DOL/EBSA.

Clinician or prior-auth team handling this on the practice side? See Highmark's prior-authorization criteria by drug: Highmark PA criteria on ApprovalHelp.