Dr. Carey on the Response-Guided Therapy in HER2+ Breast Cancer

Lisa A. Carey MD, ScM, FASCO, L. Richardson and Marilyn Jacobs Preyer Distinguished Professor for Breast Cancer Research, deputy director of Clinical Sciences, University of North Carolina (UNC)-Chapel Hill Breast Cancer Clinical Research, UNC Chapel Hill, UNC Lineberger Comprehensive Cancer Center, discusses the use of response-guided therapy in HER2-positive breast cancer.

Carey shared information on the use of response-guided therapy in non-metastatic HER2-positive breast cancer at the 40th Annual Miami Breast Cancer Conference®. In some ways, response-guided therapy has already been integrated into the treatment of patients with HER2-positive breast cancer, Carey begins. With neoadjuvant therapy, it is possible for oncologists to minimize surgery, Carey says, adding that clinicians can also tailor the use of more aggressive drugs, such as ado-trastuzumab emtansine (T-DM1; Kadcyla) based on whether a patient has residual disease. Additionally, patients who have a pathologic complete response (pCR) to neoadjuvant therapy can do very well without additional therapy, Carey continues.

In her presentation, Carey also discussed ways response-guided therapy can be further improved. Ongoing clinical trials are evaluating response-guided therapy, including the phase 2 CompassHER2-pCR trial (NCT04266249) examining whether adjuvant chemotherapy can be decreased for patients with HER2-positive breast cancer who have a pCR neoadjuvant chemotherapy and targeted therapy, and the phase 3 CompassHER2-RD trial (NCT04457596) looking at T-DM1 plus tucatinib (Tukysa) vs T-DM1 for patients at a high risk of relapse.

If CompassHER2-pCR is successful, it could allow clinicians to utilize a de-escalated regimen with less chemotherapy, Carey notes. If patient achieves a pCR complete response, even if they started with a larger or node-positive cancer, patients would not have to receive more chemotherapy and could get by with one chemotherapy drug, Carey explains.

CompassHER2-RD will look at the other end of the spectrum for patients who have high-risk residual disease. By adding tucatinib to T-DM1, investigators hope to address whether the combination can help prevent relapse in patients who currently have relapsed risk of about 20%, Carey concludes.