The US Food and Drug Administration has approved a new drug to treat HER2-positive late-stage (metastatic) breast cancer. The drug has been shown to extend remission by about six months.
Perjeta is designed for patients who have not been treated for metastatic breast cancer with an anti-HER2 therapy or chemotherapy previously. Perjeta is combined with another anti-HER2 drug and docetaxel, a type of chemotherapy..
HER2 is a protein involved in normal cell growth. Some types of cancer cells (HER2-positive), including some breast cancers, have excessive amounts of the protein. In these HER2-positive breast cancers, the protein promotes cancer cell growth and survival.
Perjeta is given intravenously. It's believed to work by attacking a different part of the HER2 protein than trastuzumab, which reduces the growth and survival of HER2-positive breast cancer cells.
There are production issues that could potentially affect the long-term supply of Perjeta. As a result, the FDA limited its approval to drug product that has not been affected by those issues. Genentech, the manufacturer of Perjeta, has committed to take steps to resolve these production issues in a timely manner.
“Given the need for additional treatments for metastatic breast cancer, we made the decision to approve this drug today and not to delay its availability to patients pending resolution of the production issues relating to future supply,” said Janet Woodcock, MD, director of FDA’s Center for Drug Evaluation and Research. "Genentech is currently developing a plan to mitigate the effect on patients of any potential shortage of Perjeta.”
“Since trastuzumab was first approved more than a decade ago, continued research has allowed us to better understand the role HER2 plays in 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. “This research provided the background to combine two targeted drugs – trastuzumab and Perjeta with docetaxel to slow disease progression in breast cancer.”
The therapy was reviewed under the agency’s priority review program, which provides for an expedited six-month review of drugs that may offer major advances in treatment.
Perjeta safety and effectiveness were evaluated in a single clinical trial involving 808 patients with HER2-positive metastatic breast cancer. Participants were randomly assigned to receive a combination of Perjeta, trastuzumab and docetaxel, or a combination of trastuzumab and docetaxel with a placebo.
The study was designed to measure how long a patient lived without the cancer progressing - progression-free survival (PFS). Those treated with the Perjeta combination had a median PFS of 18.5 months, while those treated with a placebo combination had a median PFS of 12.4 months.
The most common side effects of Perjeta in combination with trastuzumab and docetaxel were diarrhea, hair loss, decreased infection-fighting white blood cells, nausea, fatigue, rash and nerve damage (peripheral sensory neuropathy).
Perjeta has been approved with a Boxed Warning alerting patients and healthcare professionals to the potential risk of death or severe effects to a fetus. As a result, a woman's pregnancy status needs to be known before starting Perjeta treatment .
Perjeta is marketed by Genentech, a member of the Roche Group.