Dr. Dhakal on the Evolution of Pertuzumab Regimens in HER2+ Breast Cancer

Ajay Dhakal, MBBS, assistant professor, Department of Medicine, Hematology/Oncology, the University of Rochester Medical Center, discusses the two key trials supporting the use of pertuzumab (Perjeta) as a standard-of-care regimen in HER2-positive breast cancer. 

In 2012, the dual anti-HER2 combination of pertuzumab plus trastuzumab (Herceptin) and chemotherapy gained FDA approval for the treatment of patients with metastatic HER2-positive breast cancer according to results from the phase 3 CLEOPATRA trial (NCT00567190), Dhakal begins. In the trial, pertuzumab in combination with trastuzumab (Herceptin) and docetaxel was compared with a placebo regimen in patients who previously received no more than one prior hormonal treatment. The regimen demonstrated a significant improvement in progression-free survival and overall survival in this patient population and helped establish pertuzumab as a standard frontline treatment for patients with metastatic HER2-positive breast cancer, Dhakal states.

Although pertuzumab was proven effective in the metastatic setting, its use in the adjuvant setting required further exploration, Dhakal continues. The phase 3 APHINITY trial (NCT01358877) compared pertuzumab in combination with standard-of-care (SOC) trastuzumab and chemotherapy vs trastuzumab and chemotherapy alone in the adjuvant setting. The regimen was evaluated in patients with node-positive or high-risk node-negative HER2-positive, operable breast cancer.

Results showed that the addition of pertuzumab to trastuzumab and chemotherapy significantly improved 3-year invasive disease-free survival in patients with node-positive HER2-positive breast cancer, Dhakal says. However, no statistically significant benefit was observed with the regimen in node-negative patients, he notes. Based on these results, pertuzumab plus trastuzumab and chemotherapy was subsequently approved for use in the adjuvant setting in 2017. This regimen has been incorporated into the adjuvant setting as a SOC for node-positive patients, Dhakal concludes.