A Phase III Study of Atezolizumab Immunotherapy or Placebo plus Chemotherapy, Followed by Paclitaxel/Trastuzumab/Pertuzumab in Patients with Stage III HER2-Positive Breast Cancer that Spread to the Lymph Nodes


Full Title

PAC Protocol: A Phase III, Randomized, Double-blind, Placebo-controlled Clinical Trial to Evaluate the Efficacy and Safety of Atezolizumab or Placebo in Combination with Neodadjuvant Doxorubicin + Cyclophosphamide Followed by Paclitaxel + Trastuzumab + Pertuzumab in Early HER2-positive Breast Cancer (WIRB)


Drugs such as trastuzumab and pertuzumab work by targeting a protein overproduced by many breast cancers called HER2. In this study, researchers are evaluating the use of these drugs in combination with other medications, including immunotherapy, in women with stage III HER2-positive breast cancer that has spread to the lymph nodes under the arms.

Before breast cancer surgery, patients will be randomly assigned to receive either atezolizumab immunotherapy plus chemotherapy (doxorubicin, cyclophosphamide, paclitaxel), trastuzumab, and pertuzumab OR placebo (inactive treatment) plus chemotherapy, trastuzumab, and pertuzumab. After surgery, if the cancer has not completely disappeared, patients may receive trastuzumab emtansine in combination with atezolizumab or placebo.

Atezolizumab works by boosting the power of the immune system to find and kill cancer cells. The chemotherapy drugs used in this study are standard treatments for breast cancer. All medications in this study are given intravenously (by vein).


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have stage III (clinical T4 or N2-N3) HER2-positive breast cancer that has spread to the underarm lymph nodes.
  • Patients may not have received prior treatment for breast cancer
  • Patients’ tumors must be more than 2 cm in size.
  • Patients must be physically well enough that they are fully ambulatory, capable of all self-care, and capable of all but physically strenuous activities. As an example, patients must be well enough that they would be able to carry out office work or light housework.
  • This study is for patients age 18 and older.

For more information and to inquire about eligibility for this study, please contact Dr. Chau Dang at 646-497-9064.





Disease Status

Newly Diagnosed