PHESGO combines IV PERJETA (pertuzumab) and Herceptin (trastuzumab) into 1 injection
PERJETA and Herceptin are two HER2-targeted therapies. While they work together, each treatment is designed to block a different part of the HER2 receptor to stop cells from growing and dividing into new cancer cells. Normal cells also have HER2 receptors, so therapies like PERJETA with Herceptin, or PHESGO, may also affect them.
PHESGO is injected under the skin and works in the same way as IV PERJETA and Herceptin to treat HER2+ breast cancer. PHESGO also contains hyaluronidase, a protein that helps the body absorb the two medicines and allows them to be given as a single injection under the skin in just minutes.
PHESGO may help make treatment appointments go faster
PHESGO is a single ~5-minute injection given under the skin,* while PERJETA + Herceptin are given as an intravenous (IV) infusion that can take about 60-150 minutes.
*The first dose is given in ~8 minutes. This does not account for observation time and other aspects of treatment. Actual clinic time may vary.
Did you know?
In a clinical study, 85% of people preferred PHESGO over PERJETA + Herceptin and the most common reason was less time spent in the clinic.
Patient experiences may vary.
Patient compensated by Genentech.
“For me, the main benefit of receiving PHESGO is that it can be given faster than the IV treatments I was receiving.”
Watch Jen’s story to hear more about her experience with HER2+ breast cancer and PHESGO.
Financial support is available for PHESGO
Most major insurance plans, including private/commercial and public insurance plans, provide coverage for PHESGO*. There may be options available to help you afford your medicine.
*Data current as of 10/2025. (Data on file. Genentech, Inc. MMIT Analysis. HLI Lives Database.) Insurer policies may vary and are subject to change. Individual out-of-pocket cost will vary depending on plan.
ASK IF PHESGO IS RIGHT FOR YOU
Your doctor can answer any questions you have about PHESGO.
What is PHESGO?
PHESGO is a prescription medicine approved for use in combination with chemotherapy for:
- use prior to surgery (neoadjuvant treatment) in adults with HER2+, locally advanced, inflammatory, or early stage breast cancer (tumor is greater than 2 cm in diameter or node-positive). PHESGO should be used as part of a complete treatment regimen for early breast cancer.
- use after surgery (adjuvant treatment) in adults with HER2+ early breast cancer that has a high likelihood of coming back.
PHESGO is also approved for use in combination with docetaxel in adults who have HER2+ breast cancer that has spread to different parts of the body (metastatic) and who have not received anti-HER2 therapy or chemotherapy for metastatic breast cancer.
What are the most serious side effects of PHESGO?
PHESGO may cause heart problems, including those without symptoms (such as reduced heart function) and those with symptoms (such as congestive heart failure).
- The risk for and seriousness of these heart problems are highest in people who received both PHESGO and a certain type of chemotherapy (anthracycline)
- Your doctor will check for signs of heart problems before, during, and after treatment with PHESGO. Based on test results, your doctor may hold or discontinue treatment with PHESGO
- Contact a healthcare professional immediately for any of the following: new onset or worsening shortness of breath, cough, swelling of the ankles/legs, swelling of the face, palpitations, weight gain of more than 5 pounds in 24 hours, dizziness or loss of consciousness
Receiving PHESGO during pregnancy can result in the death of an unborn baby and birth defects.
- Birth control should be used while receiving PHESGO and for 7 months after your last dose of PHESGO. If you are a mother who is breastfeeding, you should talk with your doctor about either stopping breastfeeding or stopping PHESGO
- If you think you may be pregnant, you should contact your healthcare provider immediately
- If you are exposed to PHESGO during pregnancy, or become pregnant while receiving PHESGO or within 7 months following the last dose of PHESGO, you are encouraged to report PHESGO exposure to Genentech at 1-888-835-2555
PHESGO may cause serious lung problems.
- Your doctor may check for signs of lung problems including:
- Severe shortness of breath
- Fluid in or around the lungs
- Weakening of the valve between the heart and the lungs
- Not enough oxygen in the body
- Swelling of the lungs
- Scarring of the lungs
Who should not receive PHESGO?
- PHESGO should not be used in patients who are allergic to pertuzumab, trastuzumab, hyaluronidase, or to any of the ingredients in PHESGO
What are other possible serious side effects?
- PHESGO may worsen low white blood cell counts caused by chemotherapy: Low white blood cell counts can be life threatening and were seen more often in patients receiving Herceptin® (trastuzumab) plus chemotherapy than in patients receiving chemotherapy alone. Your doctor may check for signs of low white blood cell counts when he or she examines you
- PHESGO may cause administration-related reactions: PHESGO is given as an injection. The active ingredients in PHESGO have been associated with severe administration reactions, including hypersensitivity or anaphylaxis, which can be fatal. Talk to your doctor if you feel any symptoms. The most common symptoms include dizziness, nausea, chills, fever, vomiting, diarrhea, hives, swelling of the skin, breathing problems, or chest pain
What are the most common side effects?
The most common side effects of PHESGO when given with chemotherapy as part of an early breast cancer regimen are:
- Hair Loss
- Nausea
- Diarrhea
- Low levels of red blood cells
- Weakness
The most common side effects of PHESGO when given with docetaxel for treatment of breast cancer that has spread to other parts of the body (metastatic) are:
- Diarrhea
- Hair loss
- Low levels of white blood cells with or without fever
- Nausea
- Feeling tired
- Rash
- Damage to the nerves (numbness, tingling, pain in hands/feet)
What should I know about side effects with PHESGO?
- Not all people have serious side effects; however, side effects with PHESGO therapy are common. It is important to know what side effects may happen and what symptoms you should watch for
- Your doctor may stop treatment if serious side effects happen. Be sure to contact your healthcare team right away if you have questions or are worried about any side effects
You are encouraged to report side effects to Genentech and the FDA. You may report side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Genentech at 1-888-835-2555.
Talk to a healthcare professional for more information about the benefits and risks of PHESGO.
Please see full Prescribing Information for additional Important Safety Information, including most serious side effects.
If you cannot afford your medication, visit phesgo.com/financial-support for financial assistance information.