Pyrotinib: A promising Tyrosine Kinase Inhibitor for treating Breast Cancer

Abstract

Globally breast cancer is the second leading cause of mortality in women. The past two decades have seen tremendous progress in understanding and treating the disease, leading to more efficient and less toxic regimens. Anti-HER2 cancer drugs, particularly for metastatic breast cancer (MBC), are key for effective treatment. Lapatinib and neratinib are Food and Drug Administration (FDA) approved, while pyrotinib, a novel and potentially safer HER2-targeted drug, shows promise in treating HER2-positive MBC. Phase I and II trials demonstrated pyrotinib's safety and efficacy, particularly when combined with capecitabine. Compared to lapatinib, pyrotinib achieved significantly higher overall response rates and prolonged progression-free survival (PFS) in patients with HER2-positive MBC previously treated with standard therapies. Notably, pyrotinib also exhibited anti-tumor activity against brain metastases, a common challenge in HER2-positive MBC. In addition to performing well, pyrotinib is more tolerable, with manageable side effects, than the standard treatment, like trastuzumab.  While conditionally approved in China, further research is needed to fully establish pyrotinib's safety and efficacy profile. Ongoing phase IV trials in China and a phase I trial in the USA are crucial steps. Overall, pyrotinib offers a promising new option for HER2-positive breast cancer treatment, potentially with a better safety and efficacy profile than existing drugs.