BOSTON — New studies on antibody-drug conjugates (ADCs) for various breast cancer subtypes were presented at the American Society of Clinical Oncology (ASCO) meeting. Paolo Tarantino, an MD and PhD at Dana-Farber Cancer Institute in Boston, discussed the role of these ADCs in metastatic triple-negative breast cancer.

TROP2 ADCs were a focus of the discussions. Data regarding sacituzumab govitecan (Trodelvy) was presented in the ASCENT-03 and ASCENT-04 trials. Datopotamab deruxtecan (Dato-DXd; Datroway) was also discussed in the context of TROP2 ADCs. "We just kept seeing the wave of ADCs helping across settings, across subtypes, in triple-negative disease, more data with the TROP2 ADCs, sacituzumab govitecan [Trodelvy], in ASCENT-03 and -04, and datopotamab deruxtecan [Dato-DXd; Datroway]," Tarantino said.

An ADC developed in China, iza-bren (izalontamab brengitecan), was also part of the discussion. This treatment improved progression-free survival and overall survival in Chinese patients. "We saw this new ADC coming from China, iza-bren [izalontamab brengitecan], extremely effective, improving PFS [progression-free survival] and OS [overall survival] in Chinese patients," Tarantino said.

Despite the observed benefits, ADCs are associated with toxicities. Iza-bren, for instance, caused neutropenia and anemia. Management strategies for side effects associated with Dato-DXd include the use of mouthwash, eye drops, and avoiding contact lenses. "And now we really need to figure out how to sequence these drugs," Tarantino said.

Why It Matters

The discussions at the ASCO meeting highlight advancements in antibody-drug conjugates (ADCs) for metastatic breast cancer, covering multiple subtypes. The introduction of new treatments, such as iza-bren, which has shown improved survival rates in Chinese patients, alongside ongoing research on TROP2 ADCs like sacituzumab govitecan and datopotamab deruxtecan, indicates a developing area in cancer treatment. However, the associated toxicities and the need for effective management strategies, as well as establishing optimal drug sequencing, remain current challenges for clinicians.