Pyrotinib shows therapeutic potential for brain metastasis

The novel pan-HER2 tyrosine kinase inhibitor (TKI) pyrotinib yields survival gains in breast cancer patients with brain metastasis, especially when used in combination with surgery or radiotherapy, as shown in a study.

The study included 168 patients with HER2-positive metastatic breast cancer (MBC), of whom 39 were diagnosed with brain metastasis at baseline. Among these 39, 17 patients (43.59 percent) underwent surgery (n=4) or radiotherapy (n=15) combined with pyrotinib and 22 patients (56.41 percent) did not undergo surgery or radiation.

Pyrotinib treatment resulted in a median progression-free survival (PFS) of 8 months and a median overall survival (OS) of 19.07 months in the overall population. Both outcomes worsened in the presence of high tumour mutation burden (OS, p=0.0072; PFS, p=0.0028).

In the group of 39 patients with brain metastasis, the median PFS and OS were 8.67 and 13.93 months, respectively. Those who did vs did not undergo surgery/radiation had longer survival (PFS: 9.97 vs 7.73 months; p=0.19; OS: 20.67 vs 12.43 months; p=0.021).

The clinical benefit rate was also more favourable in the group of patients who received surgery/radiation with pyrotinib (58.6 percent vs 41.4 percent), whereas the objective response rate was slightly lower (24.1 percent vs 31.0 percent).

The findings indicate the potential utility of pyrotinib for the treatment of brain metastasis and that tumour mutational burden could be explored as a biomarker for predicting PFS and OS. More studies are needed.