Phesgo: What to Expect, Side Effects, and More
Phesgo (chemical name: pertuzumab, trastuzumab, and hyaluronidase-zzxf) is a fixed-dose combination of Herceptin: (chemical name: trastuzumab), Perjeta (chemical name: pertuzumab), and hyaluronidase-zzxf to treat all stages of HER2-positive breast cancer. This includes:
before surgery for early-stage or inflammatory HER2-positive breast cancer
after surgery for early-stage HER2-positive breast cancer with a high risk of recurrence
Phesgo is also used in combination with Taxotere (chemical name: docetaxel) to treat HER2-positive metastatic breast cancer that has not been treated with anti-HER2 therapy or chemotherapy.
See Phesgo prescribing information.
How Phesgo works
Both Herceptin and Perjeta are HER2 inhibitors. They work against HER2-positive breast cancer by blocking the chemical signals that tell the cancer cells to grow. Hyaluronidase-zzxf is an enzyme that helps the body absorb Herceptin and Perjeta. This formulation allows Herceptin and Perjeta to be given by injection rather than by intravenous infusion.
What to expect during Phesgo treatment
Phesgo combines fixed doses of Herceptin and Perjeta, plus hyaluronidase-zzxf, in one vial. Phesgo is injected under the skin into a person’s thigh. The first dose of Phesgo takes about 8 minutes to inject and each dose after that takes about 5 minutes, so the time to receive each dose is much shorter than getting an intravenous infusion of the medicines.
Because it’s given as an injection, a healthcare professional may be able to give you Phesgo in your home once chemotherapy infusions end, avoiding a trip to a treatment center.
You’ll likely receive Phesgo for one year if you are receiving treatment for early-stage breast cancer.
Phesgo side effects
Like almost all breast cancer medicines, Phesgo can cause side effects, some of them severe.
The most common side effects of Phesgo when given with chemotherapy to treat early-stage HER2-positive breast cancer are:
The most common side effects of Phesgo when given with Taxotere to treat metastatic HER2-positive breast cancer are:
diarrhea
hair loss
nausea
peripheral neuropathy (numbness, tingling, or pain in the hands and feet)
When Phesgo is given alone (without chemotherapy), the most common side effects are:
pain at the injection site
fatigue
rash
Phesgo also may cause serious side effects, including:
Heart problems: Phesgo may cause serious heart problems, including some that don’t have symptoms, such as reduced heart function, and some that do have symptoms, such as congestive heart failure. You will receive regular tests of your heart function during treatment with Phesgo. Symptoms to watch for include swelling of the ankles or legs, shortness of breath, cough, or weight gain of more than 5 pounds in less than 24 hours. Contact your doctor immediately if you have any of these symptoms. Your risk of heart problems is higher if you are receiving Phesgo in combination with anthracycline chemotherapy. If you are prescribed Phesgo, you will receive a heart test before treatments begin.
Lung problems: Phesgo may cause inflammation of the lungs, which can be life-threatening. Symptoms include trouble breathing, a chronic cough, and tiring easily.
Severe neutropenia: Neutropenia means you have abnormally low levels of neutrophils, a type of white blood cell. People with neutropenia have a much higher risk of getting serious infections. Your doctor will monitor your neutrophil counts while you are being treated with Phesgo.
Injection site reactions: Because Phesgo is given as an injection, a small number of people have had reactions at the injection site or anaphylaxis. Anaphylaxis is a severe allergic reaction that can cause hives, low blood pressure, dizziness, chills, and trouble breathing. Your healthcare provider will closely monitor you for 30 minutes after your first dose of Phesgo. For later doses, you will be monitored for 15 minutes. Tell your doctor immediately if you have any of the symptoms of anaphylaxis.
You shouldn’t take Phesgo if you’re pregnant or planning to become pregnant. You should use effective contraception during treatment and for seven months following your last dose.
Real patient reviews
Members of our community discuss their experiences with Phesgo in the community forum. Here are some of their comments. Remember, it's very important to talk to your doctor about any side effects you're having and ask about ways to manage them.
“I’ve been on Phesgo … for almost two years. [I have itching on my forearms] … I’m still getting some relief with external creams and lotions. I also have a drippy nose —annoying but manageable.” —lakehousegal
“I decided to go ahead with the dual anti-her2 (PHESGO > Trastuzumab + Pertuzumab). Got my first injection 3 weeks ago along with Paclitaxel. So far not too bad. Quite a lot of joint pain / headaches etc. but can't really tell whether these are caused by Paclitaxel or Phesgo just yet.” —jlgif94
“Still no real side effects from Phesgo. Hard to believe that something can kill my HER2+ cancer but not cause the rest of me any issues.” —harrow
Read more in our Phesgo discussion forum.
Paying for Phesgo
The cost of Phesgo may vary. The price you’ll pay depends on the drug manufacturer, your health insurance provider and plan, where you live, and the pharmacy you use.
Note: Your insurance company may require you to get prior authorization before covering Phesgo.
Learn more about financial assistance and medicine cost-lowering tips.
— Last updated on December 21, 2024 at 6:19 PM
