There is a new emerging treatment option for metastatic HER2-positive breast cancer. Following very encouraging & positive results from two clinical trials these options have emerged. The trials tested the drugs tucatinib and trastuzumab deruxtecan (Enhertu) in women who had been previously treated for metastatic breast cancer that overproduces the HER2 protein, known as HER2-positive breast cancer.
In one of the trials women treated with tucatinib in addition to trastuzumab and capecitabine lived longer than women who received only trastuzumab & capecitabine. The treatment also benefited women in the trial whose cancer had spread to the brain, a particularly challenging group to treat.
Trastuzumab deruxtecan was tested in a smaller trial, called DESTINY-Breast01, and wasn’t compared directly with another treatment. But many women in the study who received the drug saw their tumors shrink and lived for an extended period without their cancer getting worse.
In Dec 2019 results of both the clinical trials was presented at San Antonio Breast Cancer Symposium (SABCS) and was also published in New England Journal of Medicine.
Although there have been several severe side effects reported. Specially with trastuzumab deruxtecan, many patients has lung infections also leading to deaths. Hence more studies and care is required before these regimen comes into universal protocol.
FDA’s approval of trastuzumab deruxtecan comes with warning of lung related infections called as Interstitial Lung Disease (ILD).
Her 2 positive breast cancer patients whose cancer has also spread to brain were also included in both these trials. Usually in trials of breast cancer patients whose cancer has spread to brain are excluded in trials. These two trials were exception.
Based on HER2CLIMB results tucatinib, in combination with trastuzumab and capecitabine should be an exciting development in the treatment of HER 2 positive breast cancer patients.
Hope to see new drugs like these coming up in the days to come.
