FDA Support Perjeta for Breast Cancer Shrinkage

FDA supports Perjeta as breast cancer treatment

A group of United States advisors have recently sought to encourage the use of a breast cancer drug, called Perjeta. As things stand, the medicine is only employed for women suffering from advanced breast cancer. However, with the drug’s ability to shrink breast cancer tumors, many pro-Perjeta advocates are suggesting its broader application in the treatment of the first stages of the disease.

Current thinking suggests that earlier administration of the drug could reduce the need for highly invasive surgical intervention, and improved patient outcome.

Fast Tracking Perjeta

The U.S. Food and Drug Administration (FDA) recently released an online report, discussing the drug’s potential. However, the organization cites an association between Perjeta’s use and ensuing cardiac-related issues.

Despite this, an FDA advisory panel unanimously voted in favor of the drug’s medical administration; 13 votes were cast in favor of the drug, whilst no votes were issued against its use. Although it is not mandatory to adhere to the recommendations of FDA advisory panels, such a comprehensive vote will undoubtedly play a huge part in guiding future policy.

Recent news suggests the FDA could “fast-track” the process to ensure Perjeta is approved quickly. This decision is typically only reserved for medications that have shown incredible promise in early clinical trials, but have not undergone complete testing. Meanwhile, the FDA panel has issued directives to the drug company that manufactures of Perjeta, Genentech, to conduct a more comprehensive investigation into its clinical safety and efficacy.

Genentech company headquarters
Building 32, one of Genentech’s company headquarters

Genentech is a biotechnology company, and is a wholly owned subsidiary of Roche. The group has already started enrolling almost 5,000 patients into one of its large studies to determine the drug’s suitability for targeted treatment of breast cancer.

A Treatment for Early Stage Breast Cancer

Dr. Amy Tiersten, an associate professor working for the division of hematology and medical oncology in New York, expressed her excitement at the recent news. Tiersten explains how Perjeta might be used to treat breast cancer, during the earlier stages of the disease:

“… the really exciting information is when this can be translated into earlier stages of disease, where we can completely eradicate the disease and cure more women.”

Perjeta was originally approved by the FDA for treatment of metastatic breast cancer. Clinical trials had shown its promise in improving survival rate amongst women who had the HER2-positive form of metastatic breast cancer.

During recent investigations, Perjeta was delivered to patients, alongside standard, non-surgical treatment regimes (Herceptin and chemotherapy), resulting in 39 percent of participants experiencing no detectable levels of cancer. The women then underwent surgery to confirm the existence or absence of cancer, following Perjeta-based treatment, and to remove any residual cancer.

What is Perjeta?

HER2 receptor dimerizes with HER3, prompting cell division
Breast cancer cell, expressing the HER2 surface receptor protein. Once HER2 binds to HER3, the cell undergoes cell division and growth

Perjeta is a monoclonal antibody, which is capable of binding to an external receptor, localized to the surface of breast cancer cells. The receptor in question is called human epidermal growth factor receptor 2 (HER2), which is often overexpressed in some breast cancer patients. Once the protein antibody attaches itself to this structure, however, it precludes HER2 from bonding to another HER receptor. Since the HER2 receptor is partially responsible for promoting tumor growth, blocking its activity will delay the progression of breast cancer.

Also, as Perjeta specifically targets cells with these surface projections, there are fewer side effects. Unfortunately, treatment only works in the small subset of breast cancer patients who are HER2-positive. Approximately 80% of breast cancer sufferers are not HER2-positive and, therefore, would not qualify for the treatment.

Currently, the list of available treatment options is severely limited in HER2-positive patients, who demonstrate the early stages of breast cancer. Perjeta, on the other hand, could potentially shrink breast cancer size, improving surgical outcome. This would also mean, if the tumor size was significantly reduced, some women might not have to endure intensive mastectomies to achieve total remission.

Breast cancer represents an enormous problem in the United States, and is the second most deadly cancer in women. This year alone, the National Cancer Institute predicts almost 40,000 women will die from the disease. The FDA’s support in the use of Perjeta will be critical to Genentech moving forward. Hopefully, the breast cancer shrinking benefits of the drug will outweigh the potential risks.

By: James Fenner

FDA Press Release Source

Perjeta Information Website

CBS News Link