How Clinical Pathways Can be Used For HER2-Positive Breast Cancer Therapies

In a presentation at the 2023 Clinical Pathways Congress with the Cancer Care Business Exchange (CPC & CBEx 2023), Sayeh Lavasani, MD, MS, FRCPC, from the UC Irvine Cancer Center, discussed the numerous approaches providers can take to address different needs through clinical pathways for HER2-positive (HER2+) breast cancer care.

The age of a patient impacts the likelihood that they have developed HER2+ breast cancer. About 15%-20% of patients with breast cancer have HER2+ breast cancer. HER2+ is also more common in younger patients than older patients with breast cancer. In addition, HER2+ is associated with poorly differentiated and high-grade tumors. There are three different types of therapy doctors prescribe to patients: monoclonal antibodies (mABs) such as trastuzumab, pertuzumab, and margetuximab; tyrosine kinase inhibitors (TKIs) such as lapatinib, neratinib, and tucatinib; and antibody drug conjugates (ADCs) such as T-DM1, and T-DXd. Patients who are over the age of 65 are at a higher risk of a treatment-related high-risk adverse event and are more likely to discontinue therapy; therefore, older patients should be more closely monitored when receiving care.

Dr Lavasani explained that T-DXd is the therapy most patients choose, as it is considered the treatment of choice. In the DESTINY study, a phase 2 study of T-DXd in patients with HER2+ solid tumors, the progression-free survival (PFS) rate was about 16.4 months. The overall survival rate goal was not reached in this study. T-DXd also showed similar results in efficacy for patients within the overall population.

Another option for patients with HER2+ solid tumors is a combined therapy of margetuximab and chemotherapy. Margetuximab is a novel therapy, and patients receive 15 mg over a period of approximately 3 weeks under treatment. In the SOPHIA phase 3 trial, margetuximab was found to result in a 24% reduction in disease progression. 

Dr Lavasani ended her panel by stressing the importance of never giving up on patients and implementing new clinical trials into clinical pathways. “We need to try every single treatment that we have, and I think that we need to try all treatment options for patients—we should not dismiss a treatment option,” said Dr Lavasani. For example, although margetuximab treatment is more expensive than T-DXd, this therapy still needs to be considered for treatment in case a patient has to discontinue T-DXd therapy. Dr Lavasani believes that clinical pathways represent the best opportunity for providers to be able to make the best decisions for their patients.