FDA Approves First Treatment for Neoadjuvant Breast Cancer

Late last month, the FDA granted accelerated approval of Perjeta (pertuzumab), a monoclonal antibody, for neoadjuvant breast cancer treatment, according to a press release.

With this approval, pertuzumab, marketed as Perjeta by Genentech, has become the first drug ever approved for the indication of neoadjuvant breast cancer treatment, reported the FDA. Pertuzumab was originally approved in June 2012 for the treatment of HER2-positive metastatic breast cancer. A confirmatory trial currently is under way.

The accelerated approval stems from the results of a previous study that measured pathologic complete response (pCR), which is the absence of invasive cancer in the breast and lymph nodes. Of 417 patients randomly assigned to 1 of 4 neoadjuvant treatment regimens-trastuzumab plus docetaxel, pertuzumab plus trastuzumab and docetaxel, pertuzumab plus trastuzumab, or pertuzumab plus docetaxel-approximately 39% of patients in the pertuzumab plus trastuzumab and docetaxel group achieved pCR, compared with 21% of patients in the trastuzumab plus docetaxel group.

Pertuzumab is the first of the HER dimerization inhibitors, which work by binding to HER and thus inhibiting the dimerization of HER2 with other HER receptors. This action is reported to slow tumor growth. This new indication is 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 for cancer recurrence, metastasis, or dying from the disease, explained the FDA.

Pertuzumab is intended for use in combination with trastuzumab and other chemotherapeutic agents before surgery. It may also be followed by chemotherapy after surgery depending on the treatment regimen.

“We are seeing a significant shift in the treatment paradigm for early stage breast cancer,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “By making effective therapies available to high-risk patients in the earliest disease setting, we may delay or prevent cancer recurrences.”

As with many cancer-fighting drugs, the adverse effects can be significant. The most common adverse effects reported in patients receiving pertuzumab plus trastuzumab and docetaxel for neoadjuvant breast cancer treatment were hair loss, diarrhea, nausea, and a decreased white blood cell count. Other serious adverse effects were decreased cardiac function, infusion-related reactions, hypersensitivity reactions, and anaphylaxis.