New breast cancer drug: Promising results of PI3K inhibitor study

The drug under investigation, GDC-0941, manufactured by Genentech Inc., South San Francisco, Calif., targets the PI3K gene, which is abnormal in about 20-30 percent of patients with advanced breast cancer.

In collaboration with the Karmanos Cancer Institute in Detroit, Mich. and the Dana-Farber Cancer Institute in Boston, Mass., Dr. Von Hoff and his team at Virginia G. Piper Cancer Center Clinical Trials initially tested the drug in 97 patients with various advanced cancers. Patients experienced manageable side effects including diarrhea, nausea, taste alteration, rash, fatigue, itchiness, vomiting and decreased appetite.

The study resulted in significant shrinkage of tumors in two patients -- one with advanced cervical cancer and one with advanced breast cancer. Another patient with ampullary cancer of the pancreas is currently on the study with stable disease for more than a year.

Dr. Von Hoff is Physician-In-Chief and Distinguished Professor at the Translational Genomics Research Institute (TGen), Chief Scientific Officer at Scottsdale Healthcare and US Oncology. Virginia G. Piper Cancer Center Clinical Trials is a partnership between TGen and Scottsdale Healthcare that treats cancer patients with promising new drugs through clinical trials at the Virginia G. Piper Cancer Center in Scottsdale, Ariz.

"We are very excited about personalizing therapy for breast cancer and gynecologic cancer patients with PI3K inhibitors," said Dr. Von Hoff, who made his presentation in June during ASCO's annual meeting in Chicago. "The next step will be to test samples from breast cancer patients for PI3K mutations and treat those patients accordingly."

Breast cancer remains one of the deadliest cancers among women, with approximately 180,000 new cases each year.