In a new development, the US Food and Drug Administration (FDA) has approved a new drug combination for injection under the skin to treat people diagnosed with HER2-positive breast cancer and whose cancer is in early stages or has already spread to other parts of the body. This was announced today in a press release.
The drug can be easily administered at home by a healthcare professional and there is no need to visit the doctor’s office to get this treatment.
Today, FDA approved approved a new fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase–zzxf (PHESGO, Genentech) for neoadjuvant or adjuvant treatment of HER2-positive breast cancer.#bcsmhttps://t.co/ooWqwhzrMF
— FDA Oncology (@FDAOncology) June 29, 2020
Phesgo, the drug approved for treatment is a combination of pertuzumab, trastuzumab and hyaluronidase. These components in Phesgo are the same as those in FDA-approved intravenous pertuzumab and trastuzumab.
The approval of the drug was granted to the company, Genentech Incorporation.
— Genentech (@genentech) June 29, 2020
One criterion set for administration of the treatment is to be diagnosed by the FDA-approved companion diagnostic test.
Breast cancer has many types. One of them for which treatment was approved is called HER2-positive breast cancer. This type of breast cancer makes up approximately one-fifth of breast cancers and is usually caused by too much of a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells.
According to statistics, nearly 12 percent of women in the United States will develop invasive breast cancer at some point. That’s not it, even men can develop HER2-positive breast cancer. But most commonly the cancer is found to affect younger women. About 25 percent of all breast cancers are HER2-positive.
The drug works when pertuzumab and trastuzumab bind to sites on the receptor HER2 and disrupt signaling to stop cancer cell growth.
The drug combo can be used in combination with chemotherapy and could continue to be administered at home by a qualified health care professional once the chemotherapy regimen is finished to achieve better results.
According to FDA, right now most patients with HER2-positive breast cancer receive trastuzumab and pertuzumab at infusion centers. With a new administration route, Phesgo offers an out-patient option for patients to receive trastuzumab and pertuzumab.
This is especially significant now amid the raging COVID-19 pandemic. This can mean more people can be treated for this life-threatening condition in the comfort and safety of their own home.
The approval for this drug comes based on the results of a non-inferiority study in patients with HER2-positive early breast cancer. The study showed that this drug was as effective as IV pertuzumab and IV trastuzumab for treatment of this type of cancer.
Trastuzumab is especially effective in treatment of this breast cancer as it helps block the cancer cells from receiving chemical signals that spur growth.
In a previous study of more than 4,000 women it was seen that trastuzumab significantly reduced recurrence and improved survival when added to chemotherapy in early stage HER2-positive breast cancer.
With administration of trastuzumab the 10-year survival rate increased from 75.2 percent with chemotherapy alone to 84 percent. Rates of survival without recurrence also continued to improve. The 10-year disease-free survival rate increased from 62.2 percent to 73.7 percent.
The new drug combo approved by the FDA was also found to be safe compared to individual IV pertuzumab and IV trastuzumab, except for administration-related reactions, which were higher with Phesgo. But those are not life-threatening or harmful in the long run.
However, the drug carries risks like potential heart failure, fetal harm and lung toxicity. The most common side effects for patients taking Phesgo were alopecia (hair loss), nausea, diarrhea, anemia (reduced number of red blood cells) and asthenia (lack of energy). Phesgo can cause worsening of chemotherapy induced neutropenia (low level of white blood cells).
FDA advises that patients who experience severe allergic reactions or severe hypersensitivity should discontinue Phesgo.
Overall this is good news for patients with HER2- positive breast cancer. Especially considering that HER2-positive breast cancer is more aggressive and more likely to recur than HER2-negative breast cancer. Recurrence can happen any time, but it usually takes place within 5 years of treatment.
The good news is that recurrence is less likely today than ever before. This is largely due to the latest targeted treatments. In fact, most people treated for early stage HER2-positive breast cancer don’t relapse.