Pertuzumab is now approved by the Food and Drug Administration for the neoadjuvant treatment of breast cancer in the preoperative setting. This is the first time the agency has approved an agent to be used in this manner.
Pertuzumab, a HER2-targeted monoclonal antibody, has been approved for use in combination with trastuzumab and docetaxel for patients with HER2-positive, locally advanced, inflammatory or early-stage breast cancer (tumor greater than 2 cm in diameter or with positive lymph nodes) who are at high risk of recurrence, metastasis, or death.
It is to be used in combination with trastuzumab and docetaxel, and "depending upon the treatment regimen used, may be followed by chemotherapy after surgery. Following surgery, patients should continue to receive trastuzumab to complete one year of treatment," the FDA announced on Sept. 30.
"We are seeing a significant shift in the treatment paradigm for early-stage breast cancer," Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA Center for Drug Evaluation and Research, said in the FDA statement. "By making effective therapies available to high-risk patients in the earliest disease setting, we may delay or prevent cancer recurrences."
The label includes the statement that the neoadjuvant indication is based on a demonstration of an improvement in pathological complete response (pCR) rate, and that "no data are available demonstrating improvement in event-free survival or overall survival."
Because this was an accelerated approval, full approval depends on the results of a confirmatory phase III study that has already enrolled about 4,800 women with HER2-positive breast cancer, a history of prior breast cancer surgery, and a high risk of recurrence, according to the FDA. This study, called APHINITY, is following patients for 10 years, with the first results expected in 2016.
Pertuzumab, marketed as Perjeta by Genentech, was initially approved in 2012 for advanced or late-stage HER2-positive breast cancer.
The accelerated approval is based on the pCR, defined as the absence of invasive cancer in the breast and lymph nodes, in a phase II study of 417 women with early HER2-positive breast cancer, randomized to one of four neoadjuvant treatment regimens. About 39% of those treated with pertuzumab, trastuzumab, and docetaxel achieved a pCR, vs. about 21% of those on trastuzumab and docetaxel. This study was the NEOSPHERE (Neoadjuvant Study of Pertuzumab and Herceptin in an Early Regimen Evaluation) study.
The most common adverse events associated with the treatment were alopecia, diarrhea, nausea, and neutropenia.
The approval was announced less than 3 weeks after the FDA Oncologic Drugs Advisory Committee voted 13 to 0 with one abstention to support approval. At the Sept. 12 meeting, several panelists remarked on the historical significance of the approval of the first drug for breast cancer in the neoadjuvant setting, but also emphasized the importance of the confirmatory trial, to confirm the effectiveness and to provide more data on the safety of the treatment, including effects on cardiac function.
The new approval pathway, using the pCR results, "has made Perjeta available to people with HER2-positive early breast cancer several years earlier than previously possible," Dr. Hal Barron, chief medical officer and head of global product development at Genentech, said in a statement. The company is investigating the option of submitting approval of pertuzumab in the neoadjuvant setting in other countries.