Pertuzumab-Based Regimen Improves Survival in HER2-Positive Early Breast Cancer

Combination treatment helped increase invasive disease-free survival in patients with an aggressive type of early breast cancer.

The combination regimen of pertuzumab (Perjeta), trastuzumab (Herceptin), and chemotherapy showed a statistically significant improvement in invasive disease-free survival (iDFS) for individuals with HER2-positive early breast cancer.

Pertuzumab is designed to specifically target and prevent the HER2 receptor from pairing with other HER receptors (EGF/HER1, HER3, and HER4) on the surface of cells, a process believed to play a role in the growth and survival of cancer cells, according to a press release.

The international, randomized, double-blind, placebo-controlled, 2-arm, phase 3 APHINITY study evaluated the safety and efficacy of pertuzumab plus trastuzumab and chemotherapy compared with trastuzumab and chemotherapy as an adjuvant therapy.

Included in the study were 4805 patients with operable HER2-positive early breast cancer, who underwent surgery, randomized 1:1 into 2 arms.

One arm received 6 to 8 cycles of chemotherapy (anthracycline or non-anthracycline-containing regimen) with pertuzumab and trastuzumab, followed by pertuzumab and trastuzumab every 3 weeks for 1 year. The other arm received 6 to 8 cycles of chemotherapy (anthracycline or non-anthracycline-containing regimen) with placebo and trastuzumab, followed by placebo and trastuzumab every 3 weeks for 1 year.

Radiotherapy and endocrine therapy could be initiated at the end of adjuvant chemotherapy, according to the release.

The primary efficacy endpoint of APHINITY is iDFS, which is defined as the time a patient lives without the recurrence of invasive breast cancer at any site or death from any cause after adjuvant therapy. Secondary endpoints included cardiac and overall safety, overall survival, disease-free survival, and health-related quality of life.

The safety profile of pertuzumab-based regimen was consistent with findings from prior studies. Additionally, no safety signals were identified.

“The results from the positive APHINITY study represent an important addition to the body of data from [pertuzumab] in the treatment of people with HER2-positive early breast cancer,” said Sandra Horning, MD, chief medical officer and head of Global Product Development of Genentech. “We look forward to discussing these adjuvant results with global regulatory authorities.”

Full results from the APHINITY trial will be presented at an upcoming medical meeting in 2017, according to the release.

“APHINITY provides yet another example of the importance of industry-academic collaborations and their value in advancing cancer care for people affected by this challenging disease.”