Dr Chaudhary on the Utilization of Trastuzumab Deruxtecan in Metastatic HER2+ Breast Cancer

Lubna Chaudhary, MD, MS, associate professor, medicine, hematology, and oncology, the Medical College of Wisconsin, discusses the ongoing investigation and utilization of fam-trastuzumab deruxtecan-nxki (Enhertu; T-DXd) in patients with metastatic HER2-positive breast cancer and compared this agent’s efficacy with that of ado-trastuzumab emtansine (Kadcyla; T-DM1).

In an OncLive® State of the Science Summit™ (SOSS), Chaudhary and colleagues from the Medical College of Wisconsin each gave presentations on topics spanning breast cancer care. Chaudhary gave her presentation on the evolution of HER2-positive and HER2-low breast cancer therapies.

Chaudhary began her presentation by discussing the inception of the DESTINY-Breast03 study (NCT03529110). This was a randomized phase 3 clinical trial that was conducted in patients with advanced HER2-positive metastatic breast cancer, Chaudhary explains. The study was designed to compare the antitumor activity, safety, and efficacy of T-DXd vs T-DM1 in patients with HER2-positive unresectable or metastatic breast cancer previously treated with trastuzumab (Enhertu) and taxane. At the time that the phase 3 trial was launched, T-DM1 had been the standard second-line drug of choice for these patients, she details. Chaudhary highlights that at the SOSS, she detailed the overarching takeaways from this pivotal study.

It is important to note the key distinctions between T-DXd and T-DM1, she expands. Both these agents are antibody-drug conjugates, though their payloads and payload-to-antibody ratios differ from each other, Chaudhary explains. T-DXd stands out as considerably more potent and effective than T-DM1, she notes.

In the DESTINY-Breast03 trial, there was a significant improvement in progression-free survival in the T-DXd group compared with the T-DM1 group, Chaudhary continues. The positive results from this trial led to the regular FDA approval of T-DXd for the second-line treatment of patients with metastatic HER2-positive breast cancer, establishing it as the new standard of care in this population and inducing a shift in clinical practice, she concludes.