Targeted therapies have extended life for HER2 positive breast cancer patients for 20 years, but experts say when the disease reaches stage four it spreads to the brain in over 30 percent of patients. Those patients were barred from clinical trials for their cancer, until now.

Dikla Benzeevi has been fighting metastatic HER2 positive breast cancer for sixteen years. She’s tried 14 drugs and seven lines of therapy.

“Therapy seems to work for about one and a half to two years, and then I start having progression or a new metastasis,” Dickla said.

She was running out of options. Then, her doctor, Sara Hurvitz, MD, Associate Professor of Medicine, and Director, Breast Oncology at UCLA/Jonsson Comprehensive Cancer Center told her about the HER2 Climb study. It uses an experimental drug called Tucatinib along with Herceptin and a chemo drug called Xeloda.

“It’s a small molecule that gets into the cancer cell. It targets the inside of the HER2 receptor and stops it from functioning on the inside,” said Dr. Hurvitz.

Tucatinib is small enough to cross the blood-brain barrier, which gives hope to women whose cancer has spread to the brain.  

“it’s a very unique opportunity for women who have this very high-risk type of metastatic breast cancer to receive a drug that is potentially going to be effective in that type of disease,” Dr. Hurvitz continued.

Dickla has been in the trial for 11 months. She doesn’t know if she’s getting tucatinib or a placebo, but tumors in her lungs are staying small.

“At the minimum, I hope that it keeps me stable, it keeps me feeling good; that I can have the kind of life I want to lead and that I can have it for a long time,” she said..

An early phase clinical trial showed that more than 40 percent of women with brain metastases had shrinkage of their brain tumors, giving Dickla reason to hope.

Tucatinib attacks only the HER2 protein, so it’s not as toxic as other therapies. The HER2 climb study opened in 2015 and is still enrolling patients at 171 trial sites. Dr. Hurvitz doesn’t anticipate getting results back for a couple of years. If they’re positive, she hopes this new therapy could be given to early stage patients, at high risk of relapse, to prevent brain metastases.