The combination is meant for women with HER2-positive early breast cancer who have traces of cancer in their lymph nodes and/or have hormone negative disease. It should be given for a year after surgery or until the disease comes back.
This approval opens a new treatment opportunity to prevent the spreading and recurrence of this aggressive cancer type, with affects approximately 20 percent of women diagnosed with breast cancer.
“Our treatment goal for early breast cancer is to cure the disease, and a big part of this is to prevent the disease from coming back,” Katarzyna Jerzak, MD, oncologist at Sunnybrook Odette Cancer Centre, said in a press release.
“The data show this new treatment option can be clinically meaningful and can significantly reduce the risk of recurrence for some women with breast cancer,” she said.
Perjeta, developed by Roche, is an inhibitor of the HER2 receptor, a protein known to participate in breast cancer growth and survival. The medicine works by preventing the HER2 protein from binding the HER3 protein, preventing its signaling.
But other HER2 inhibitors, like Herceptin, prevent the HER2 protein from binding to similar HER2 proteins. Researchers believe that blocking both mechanisms could provide a more effective inhibition of the HER2 signaling.
Health Canada’s decision was supported by data from the ongoing APHINITY Phase 3 trial (NCT01358877), which includes 4,804 patients with operable HER2-positive early breast cancer.
Participants were randomized to receive either Perjeta or placebo, in combination with Herceptin and chemotherapy, following surgical removal of their tumor.
To date, results show a 19% reduction in the risk of invasive breast cancer recurrence or death in patients receiving Perjeta, compared to those receiving placebo.
The combination was particularly beneficial for patients with lymph node-positive or hormone receptor-negative breast cancer, who saw a 23% and 24% reduction in their risk of cancer recurrence or death.
The safety profile of the Perjeta regimen was consistent with that reported previously, with a low incidence of cardiac events and no new safety signals. The most common adverse side effects reported were diarrhea, nausea, alopecia (hair loss), fatigue, and vomiting.
“Thankfully there are many treatment success stories when breast cancer is diagnosed early, however many patients do have a recurrence that can progress to an incurable stage,” said MJ DeCoteau, founder and executive director of Rethink Breast Cancer. “This approval is an important milestone, as it provides another treatment option that is effective at reducing the risk of disease recurrence, an important treatment goal for patients.”
During the APHINITY trial, researchers also will evaluate the effect of Perjeta in patients’ overall survival, disease-free survival, and health-related quality of life.
The study will continue to follow participants for up to 10 years to evaluate the effectiveness and safety of the combination in the long term.