The goal is to remove as many cancer cells as possible before surgery
Based on your answers, here is information about starting HER2‑targeted therapy.
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Prepare for a conversation with your doctor
Below are some starter questions to begin a conversation with your doctor or care team:
- Can we discuss my treatment goals?
- How might adjuvant treatment help me?
- How will you know if my treatment is working?
- When will I start adjuvant treatment?

The goal of HER2-targeted treatment before surgery is to remove as many cancer cells as possible.
A study compared the effectiveness of PERJETA + Herceptin before surgery to another neoadjuvant treatment
Who was in the study?
417 people with certain types of HER2+ early breast cancer receiving treatment before surgery (neoadjuvant treatment).
What was the goal of the study?
To see if people who received PERJETA + Herceptin + chemotherapy treatment before surgery (neoadjuvant) were more likely to have no detectable cancer cells after surgery.
What were the results?
Almost twice as many people who got PERJETA + Herceptin before surgery had no detectable cancer cells in the lymph nodes and breast tissue removed during surgery, compared with people who got the other treatment.


What are the most serious side effects of PERJETA?
- PERJETA may cause heart problems, including those without symptoms (such as reduced heart function) and those with symptoms (such as congestive heart failure).
- Receiving PERJETA during pregnancy can result in the death of an unborn baby and birth defects.
What are other possible serious side effects of PERJETA?
PERJETA should not be used in patients who are allergic to pertuzumab or to any of the ingredients in PERJETA. Possible serious and sometimes fatal side effects of PERJETA include infusion-related reactions and severe allergic reactions (hypersensitivity reactions/anaphylaxis).
See additional Important Safety Information below.
If your doctor recommends PERJETA + Herceptin before surgery

PERJETA + Herceptin treatment is usually given 3-6 cycles (about 9-18 weeks) before surgery unless the side effects require the treatment to stop. There will also be chemotherapy but the dosing schedule and number of cycles will depend on which type of chemotherapy is used. Your doctor may recommend continuing HER2-targeted treatment after surgery.
Discover study results with PHESGO
- See clinical trial results
- Find out if more people preferred PHESGO or PERJETA + Herceptin
If your doctor recommends PHESGO before surgery

PHESGO treatment is usually given 3-6 cycles (about 9-18 weeks) before surgery unless the side effects require the treatment to stop. There will also be chemotherapy but the dosing schedule and number of cycles will depend on which type of chemotherapy is used. Your doctor may recommend continuing HER2-targeted treatment after surgery.
Summarizing the key differences between these two treatments
PERJETA + Herceptin | PHESGO | |
---|---|---|
Active ingredients | pertuzumab trastuzumab | pertuzumab trastuzumab hyaluronidase |
Administration method | Intravenous (IV) infusion, given by a care provider | Subcutaneous (under the skin) injection, given by a care provider |
Administration time | About 1-2.5 hours*:
|
Your first dose is given in about 8 minutes. Other injections take about 5 minutes.* |
Study results summary | A study comparing PHESGO to PERJETA + Herceptin found no major difference is expected in how well PHESGO works. By taking PHESGO, you’re taking the same medicines, just in less time. There are side effects associated with both treatments. The comparison study did not find any significant difference between the 2 treatments. |
*This does not account for observation time and other aspects of treatment. Actual clinic time may vary.
Keep in mind that this site is for educational purposes only and that the options here are just some of the treatments you may be eligible for. Your primary sources of information should always be your doctor and the professionals who make up your care team. Only they can give you medical advice about your disease and treatment.