Patritumab deruxtecan in breast cancer treatment: a drug evaluation.

Breast cancer is a complex disease due to its heterogeneity. While there have been impressive advancements in the treatment of the different breast cancer subtypes, challenges persist when the tumor develops acquired treatment resistance and finally progresses on a given therapy. Since human epidermal growth factor receptor 3 (HER3) plays a key role in developing resistance to several anticancer therapies, many efforts have been performed over the last decades to effectively target HER3. However, most of these attempts have been unsuccessful due to their limited efficacy or severe toxicity. Numerous antibody-drug conjugates (ADCs) targeting HER3 are now being explored. Patritumab deruxtecan (U3-1402; HER3-DXd), the most advanced ADC targeting HER3 in clinical development, has demonstrated significant antitumor activity and a manageable safety profile in patients with breast cancer. This efficacy has been observed across diverse tumor subtypes and varying levels of HER3 expression. In this review, we will analyze the results of clinical trials investigating HER3-DXd in breast cancer and explore its potential role in future clinical applications and treatment algorithms.