YOUR HEALTH: Better understanding HER2 breast cancer treatments

LOS ANGELES – Dikla Benzeevi has been fighting metastatic HER2 positive breast cancer for sixteen years.  She's tried fourteen 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."

She was running out of options.

Targeted therapies have extended life for HER2 positive breast cancer patients for 20 years but experts say when the disease reaches Stage 4 it spreads to the brain in more than 30% of patients.

Those patients were barred from clinical trials for their cancer until now.

UCLA oncologist Sara Hurvitz is involved in a 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," explained 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," said Dr. Hurvitz.

Dikla has been in the trial for eleven months.   She doesn't know if she's getting Tucatinib or a placebo but tumors in her lungs are staying small.

"At the minimum," she said.  "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."

TREATMENT:   Approximately 12% of women in the United States will develop invasive breast cancer at some point.  Anyone, even men, can develop HER2-positive breast cancer, but it's more likely to affect younger women.   HER2-positive represents about 20% of all breast cancers.   HER2-positive breast cancer is more aggressive and more likely to recur than HER2-negative breast cancer.   Recurrence can happen anytime, but it usually takes place within  five years of treatment.   Treatment plans usually include surgery, chemotherapy, radiation, or targeted treatments.  Metastatic breast cancer is not considered curable.  Treatment can continue as long as it's working.   (Source: https://www.healthline.com/health/breast-cancer/her2-positive-survival-rates-statistics#treatments)

An early phase clinical trial showed that more than 40% of women with brain metastases had shrinkage of their brain tumors giving Dikla 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 184 trial sites including the University of Chicago and the Rush University Medical Centers in the Chicago-area.

If this story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Jim Mertens at jim.mertens@wqad.com or Marjorie Bekaert Thomas at mthomas@ivanhoe.com.