Why is PERJETA-based treatment used in early breast cancer before surgery?

The potential benefits and risks of PERJETA with Herceptin® (trastuzumab) and chemotherapy for HER2+ early breast cancer have been studied in 3 clinical trials before surgery. Learn more about how doctors check to see if a cancer is responding to treatment before surgery, and how cancer treated with PERJETA-based treatment responded.

How your doctor will tell if your cancer is responding to treatment

A pathologist checks the breast tissue and nodes removed during surgery to see how well neoadjuvant treatment worked. Neoadjuvant treatment is considered successful if cancer cells are not detected in the breast and lymph nodes. This is called a pathological complete response (pCR).

A pathological complete response is not a cure. A pathological complete response can give some information about the cancer, but it may not change a treatment plan.

PERJETA Neoadjuvant Pathological Response

More tumors had pathological complete response when given PERJETA with Herceptin and chemotherapy

PERJETA was studied in 3 clinical trials of more than 1,000 patients with HER2-positive (HER2+) early breast cancer who received breast cancer treatment before surgery. In those studies, more tumors had a pathological complete response when PERJETA with Herceptin and chemotherapy was given before surgery.

  • In one trial, PERJETA, Herceptin, and docetaxel were given together before breast cancer surgery
  • 39.3% of the breast tumors treated with this combination had a pathological complete response
  • When PERJETA wasn’t included in the combination, 21.5% of breast tumors had a pathological complete response to treatment before surgery
PERJETA Neoadjuvant pCR Chart

PERJETA works with other medications to fight cancer before surgery as part of a 1-year treatment course.

What does PERJETA treat?

PERJETA® (pertuzumab) is approved for use in combination with Herceptin® (trastuzumab) and chemotherapy for use prior to surgery (neoadjuvant treatment) in people with HER2-positive, locally advanced, inflammatory, or early stage breast cancer (tumor is greater than 2 cm in diameter or node-positive). PERJETA should be used as part of a complete treatment regimen for early stage breast cancer.

Side effects may occur with PERJETA 

What are the most serious side effects of PERJETA?
Receiving PERJETA during pregnancy can result in the death of an unborn baby and birth defects.
PERJETA may cause heart problems, including those without symptoms (such as reduced heart function) and those with symptoms (such as congestive heart failure).

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 side effects of PERJETA include infusion-related reactions and severe allergic reactions (hypersensitivity reactions/anaphylaxis).

The most common side effects of PERJETA when given with Herceptin and docetaxel as part of an early breast cancer regimen before surgery are: 

  • Hair loss
  • Diarrhea
  • Nausea
  • Low levels of white blood cells with or without a fever

Always report side effects to your healthcare team at any point in your treatment.

You are encouraged to report side effects to Genentech and the FDA. You may contact Genentech by calling 1-888-835-2555. You may contact the FDA by visiting or calling 1-800-FDA-1088.

How PERJETA is given

PERJETA is an infusion that can be given before surgery as part of a neoadjuvant treatment course for HER2+ early breast cancer.

Talking with your doctor

If you have HER2+ early breast cancer, here are questions you may want to ask your doctor.