FDA approves pertuzumab for treatment of HER2-positive metastatic breast cancer

New personalized medicine gives patients with an aggressive form of breast cancer more time without their disease worsening.

FDA has approved pertuzumab (Perjeta, Roche) in combination with trastuzumab (Herceptin) and docetaxel chemotherapy for the treatment of people with HER2-positive metastatic breast cancer (mBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease.

Pertuzumab is designed specifically to prevent the HER2 receptor from pairing (or ‘dimerising’) with other HER receptors (EGFR/HER1, HER3, and HER4) on the surface of cells, a process that is believed to play a role in tumor growth and survival. Binding of pertuzumab to HER2 may also signal the body’s immune system to destroy the cancer cells. The mechanisms of action of pertuzumab and trastuzumab are believed to complement each other, as both bind to the HER2 receptor, but to different regions. The combination of pertuzumab, trastuzumab, and chemotherapy is thought to provide a more comprehensive blockade of HER signaling pathways.

This approval is based on data from a phase 3 study (CLEOPATRA [CLinical Evaluation Of Pertuzumab And TRAstuzumab]) which showed that people with previously untreated HER2-positive mBC who received the combination of pertuzumab, trastuzumab, and docetaxel chemotherapy lived a median of 6.1 months longer without their cancer getting worse (progression-free survival, or PFS) compared to trastuzumab plus docetaxel chemotherapy (median PFS 18.5 vs 12.4 months).

In CLEOPATRA, the most common adverse reactions (rate greater than 30%) seen with pertuzumab in combination with trastuzumab and docetaxel were diarrhea, hair loss, low white blood cell count, nausea, fatigue, rash, and peripheral neuropathy (numbness, tingling, or burning sensation in the arms or legs). The most common Grade 3–4 adverse reactions (rate greater than 2%) were low white blood cell count, low white blood cell count with fever, decrease in a certain type of white blood cell, diarrhea, peripheral neuropathy, decrease in red blood cell count, weakness, and fatigue.

“[The] approval of Perjeta is an important advance in the treatment of HER2-positive metastatic breast cancer,” said Hal Barron, MD, chief medical officer and head, global product development, in a company press release. “Perjeta attacks HER2-positive tumors differently than Herceptin. Based on the way the 2 medicines work together, the combination plus chemotherapy can prolong the time before this aggressive cancer worsens compared to Herceptin and chemotherapy alone. We are very pleased to see our efforts in studying the science of HER2 translate into another personalized medicine.”

With the approval, Roche has agreed to post-marketing commitments related to the manufacturing process for pertuzumab. These include FDA review of data from the next several productions of the drug.

“We expect to meet demand for Perjeta following FDA approval. We recently identified a cell growth issue that might affect our future supply of the medicine,” said Patrick Y. Yang, PhD, head, pharma global technical operations. “We take this very seriously and are working with the FDA to ensure a consistent manufacturing process that maintains drug supply for the people who need it.”

Breast cancer is the most common cancer among women worldwide. Each year about 1.4 million new cases of breast cancer are diagnosed worldwide, and over 450,000 women will die of the disease annually. In HER2-positive breast cancer, increased quantities of the human epidermal growth factor receptor 2 (HER2) are present on the surface of the tumor cells. This is known as “HER2 positivity” and affects approximately 15% to 20% of women with breast cancer. HER2-positive cancer is a particularly aggressive form of breast cancer.