Palbociclib with Letrozole and Trastuzumab in ER/HER2+ Breast Cancer

Year of Grant: 2017

Location: United States


Breast cancer is not one disease but several types of different diseases commonly treated the same. Patients with an aggressive form of breast cancer called HER2+ breast cancer are usually treated with chemotherapy and dual HER2 targeted treatments. These treatments may cause congestive heart failure in addition to the side effects of chemotherapy.


Based on the results of large studies, it is known that some patients do not need such intense therapy but still do well. A subgroup of such patients are those with hormone driven HER2+ breast cancer. Consequently, the project team is investigating a novel regimen that omits chemotherapy and one of the newer HER2 targeted treatments, but adds a special medication called palbociclib that enhances the activity of antiestrogens.


In this three year Phase II clinical trial, a total of forty eight participants will be treated with neoadjuvant palbociclib in addition to letrozole and trastuzumab for a total of 16 weeks, consisting of four 28-day cycles. Definitive surgery will be performed within 3 to 5 weeks after the end of Cycle 4. Letrozole and trastuzumab will continue until the day of surgery.


This strategy may allow patients to be treated in an equally or more effective but less toxic manner. The team will assess on-treatment biopsies as well as evaluate the amount of cancer left in the breast after treatment. Patients who do not get a very good outcome from this therapy will have the option of all standard treatments after surgery.