||Under "When Covered," added Herceptin Hylecta (trastuzumab and hyaluronidase-oysk) for the treatment of HER2 overexpressing breast cancer indications. Reformatted "When Not Covered" section for clarity, with no change to intent. Updated Description section to reflect addition of Herceptin Hylecta to policy. Added reference to related policy for Nerlynx. Added HCPCS code J9356 to Billing/Coding section. References added. Medical Director review 12/2019. Notification given 12/31/2019 for effective date 4/1/2020.