Among women with advanced HER2-positive breast cancer, the investigational drug neratinib produced promising response rates and progression-free survival. The results of this Phase II clinical trial were published in the Journal of Clinical Oncology.
Twenty to 25 percent of breast cancers overexpress (make too much of) a protein known as HER2. Overexpression of this protein leads to increased growth of cancer cells and a worse breast cancer prognosis. Fortunately, the development of drugs such as Herceptin® (trastuzumab) that target HER2-positive cells has improved prognosis for women with HER2-positive breast cancer.
Neratinib is an investigational, oral medication that targets HER2 as well as HER4 and the epidermal growth factor receptor (EGFR).
To evaluate neratinib in the treatment of advanced, HER2-positive breast cancer, researchers conducted a Phase II clinical trial. The study enrolled 136 women with Stage IIIB, IIIC, or IV, HER2-positive breast cancer. Roughly half the women had received prior treatment with Herceptin.
All study participants were treated with oral neratinib once daily.
- 16-week progression-free survival was 59% among women who had previously been treated with Herceptin and 78% among women with no prior Herceptin.
- A response to treatment was observed in 24% of women who had been previously treated with Herceptin and 56% of women with no prior Herceptin.
- The most common side effects of neratinib were diarrhea, nausea, vomiting, and fatigue.
The researchers concluded that neratinib is active and reasonably well tolerated among women with advanced, HER2-positive breast cancer. Neratinib will continue to be evaluated in breast cancer clinical trials.
Reference: Burstein HJ, Sun Y, Dirix LY et al. Neratinib, an irreversible ErbB Receptor tyrosine kinase inhibitor, in patients with advanced ErbB2-positive breast cancer. Journal of Clinical Oncology. 2010; 28: 1301-1307.