Trastuzumab Deruxtecan (Enhertu)

Key Messages

• CADTH recommends that Enhertu be reimbursed by public drug plans for the treatment of adult patients with unresectable or metastatic HER2-low breast cancer if certain conditions are met.
• Enhertu should only be covered to treat adult patients with HER2-low breast cancer that is unresectable (cannot be removed by surgery) or metastatic (has spread to other parts of the body) who have received a prior chemotherapy for metastatic disease or had their cancer come back after surgery within 6 months of completing adjuvant chemotherapy. If the patient is hormone receptor (HR)-positive, they should have been treated with at least 1 endocrine therapy (ET) and no longer be considered candidates for further ET treatment. Patients receiving Enhertu should be in relatively good health (i.e., have a good performance status, as determined by a specialist). Patients in whom the cancer has spread to the brain or spinal cord, for whom there is spinal cord compression causing symptoms, or those with interstitial lung disease or pneumonitis should not be eligible for coverage.
• Enhertu should only be reimbursed if prescribed by clinicians with experience and expertise in treating advanced breast cancer in centres, if it is not used with other cancer treatments, and if the cost of Enhertu is reduced. Patients who experience disease progression while taking Enhertu or who cannot tolerate the drug would not be eligible for continued coverage.