Dr. Kim on Clinical Implications of ADCs in HER2+ Solid Tumors

Edward S. Kim, MD, MBA, physician-in-chief at City of Hope Orange County and vice physician-in-chief at City of Hope National Medical Center, discusses the clinical implications of antibody-drug conjugates (ADCs) in HER2-positive solid tumors.

Though ADCs are not a new development, the agents have had limited indications in the past since they had historically failed to generate improved benefits vs other approved therapies, Kim says. Recently, ADCs have had a more pronounced effect, with an increasing number of approvals for ADCs coming after agents started displaying improved safety and better targeting mechanisms, Kim adds.

Recent data surrounding fam-trastuzumab deruxtecan-nxki (Enhertu) showed that the ADC displayed efficacy in patients with HER2-positive and HER2-low breast cancer, causing a shift in how patients with breast cancer are classified and treated, Kim explains. The findings in HER2-low breast cancer showed that high overexpression of a particular receptor may not be necessary for an ADC to bind and be effective, Kim adds.

In theory, HER2 overexpression should serve as a poor prognostic factor in breast cancer, but due to effective targeted therapies such as trastuzumab (Herceptin) and trastuzumab deruxtecan, patients have a more optimistic prognosis, Kim continues. Now that an agent has displayed a benefit in patients with HER2-low breast cancer, another subset of patients could have a more favorable prognosis going forward, Kim concludes.