Dr. Tripathy on Genomically Guided Therapy in Breast Cancer

Debu Tripathy, MD, professor and chairman, Department of Breast Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses genomically guided therapy in breast cancer.

Genomically guided therapy can be used in patients, regardless of whether or not they have brain metastases, says Tripathy. Genomically guided therapy can be used to target specific mutations, which in HER2-positive breast cancer includes the PIK3CA mutation. Approximately 25% of patients with HER2-positive breast cancer harbor mutations in PIK3CA. The prevalence of these mutations is slightly higher in patients with hormone receptor–positive breast cancer, adds Tripathy.

Ongoing trials are evaluating combinations of PI3K inhibitors with trastuzumab (Herceptin) and pertuzumab (Perjeta). Another ongoing trial is testing the combination of alpelisib (Piqray) and copanlisib (Aliqopa) in select patients with breast cancer, says Tripathy. Additional alterations such as cyclin D amplification and, under selective pressure, RAS mutations have also emerged as potential targets. However, national and international collaborations will be necessary to enroll these niche patient populations onto genomically guided trials, concludes Tripathy.