A pivotal international study published in the New England Journal of Medicine and led in part by José Baselga, MD, PhD, Physician-in-Chief at Memorial Sloan Kettering Cancer Center (MSK), offers proof of better treatment options for patients with HER2-positive early breast cancer. The new international research found that the drug pertuzumab (Perjeta®) significantly improved invasive-disease-free survival (IDFS) in patients with operable HER2-positive breast cancer when added to trastuzumab (Herceptin®) and chemotherapy. The findings of this study were presented at the American Society of Clinical Oncology annual meeting today in Chicago.
In the study, more than 4,800 patients with HER2-positive breast cancer were randomly assigned to receive chemotherapy plus one year of trastuzumab with either pertuzumab or a placebo. The group receiving pertuzumab had a three-year IDFS of 94.1 percent, while the placebo group had an IDFS of 93.2 percent. The side effects from pertuzumab were minimal, and the safety profile of the pertuzumab-based regimen was consistent with that seen in previous studies.
“These results will add to the arsenal of treatment options for patients with HER2-positive breast cancer who are at a high risk of recurrence,” explained Dr. Baselga, one of the senior authors on the study. “Because of its efficacy, this regimen could become a new standard of care in treating HER2-positive breast cancer.”
Pertuzumab has been approved for use in patients with advanced metastatic HER2 breast cancer, and it has been given before surgery to remove breast tumors. The new results published today could fill a need in treating these women at an early enough stage to prevent the cancer from growing and spreading.
The benefit of pertuzumab was more pronounced in patients at a higher risk of recurrence. This includes some women who had cancer in their lymph nodes and who were estrogen receptor (ER) negative. This suggests that pertuzumab might be given specifically to patients with high-risk disease.
The HER2 gene is overexpressed in about 20 percent of breast cancers, and it is standard therapy for this group of HER2-positive patients to receive the anti-HER2 drug trastuzumab combined with chemotherapy. HER2/neu is a gene that acts like an on-off switch in cells, producing a protein called HER2. This protein normally helps control how healthy breast cells grow and divide. About one in five breast cancers either has extra copies of the HER2/neu gene or produces an oversupply of the HER2 protein. This type of cancer is called HER2 positive and makes cells grow in an uncontrolled way.
“There has been impressive progress made in a short time in the treatment of HER2-positive disease. The first trastuzumab adjuvant therapy for HER2-positive breast cancer, known as HERA, was approved in 2005 — and in 12 short years, there has been critical research that has changed the natural history of this disease. This is encouraging because the only place we can actually cure HER2-positive breast cancer is in the early stage,” said Dr. Baselga. “These positive results give us a new opportunity to have an impact and improve outcomes.”
Dr. Baselga pioneered the development of treatments for women with HER2-positive breast cancer and conducted the first clinical trial to demonstrate that patients with advanced HER2-positive breast cancer benefited from treatment with the anti-HER2 monoclonal antibody trastuzumab. He continues to lead state-of-the-art international clinical trials with trastuzumab for women before and after breast cancer surgery. In addition, he led the clinical development of the second anti-HER2 monoclonal antibody to receive US Food and Drug Administration approval, pertuzumab, and the landmark study that led to the approval of everolimus (Afinitor®) for the treatment of patients with hormone receptor-positive breast cancer.
Funded by Hoffmann-La Roche; ClinicalTrials.gov number, NCT01358877
