Alliance A012303

Clinical Trial Title ShortStop-HER2: Shortened duration of adjuvant therapy in patients with early-stage HER2+ breast cancer who achieve pCR after neoadjuvant chemotherapy with HER2 blockade
Trial Status Open to Enrollment
Start Date 09/24/2025
Location hospitals
Trial Type Cancer - Adult Oncology
Specific Condition Breast Cancer
Description This phase III trial compares 6 months of human epidermal growth factor receptor 2 (HER2)-targeted therapy to 12 months of HER2-targeted therapy for the treatment of HER2-positive (+) breast cancer in patients that had a pathologic complete response (pCR) after preoperative (neoadjuvant) chemotherapy with trastuzumab. Trastuzumab and pertuzumab are monoclonal antibodies and forms of targeted therapy that attach to a receptor protein called HER2. HER2 is found on some cancer cells. When trastuzumab or pertuzumab attach to HER2, the signals that tell the cells to grow are blocked and the tumor cell may be marked for destruction by the body's immune system. Giving 6 months of HER2-targeted therapy may work better than giving 12 months for the treatment of HER2+ breast cancer in patients that had a pCR after neoadjuvant chemotherapy with trastuzumab.
Eligibility Criteria

Eligibility Criteria

  • Patients (females and males) with clinical stage T1c-T3 (or Tx) and nodal stage N0-N1 (except T3N1 tumors, which are not eligible)
  • Patients must have no residual invasive disease in the breast or lymph nodes after the completion of neoadjuvant therapy. Residual DCIS is allowed. Patients with residual isolated tumor cells at surgery are considered node-positive and are not eligible.
  • HER2+ by ASCO/CAP guidelines.
  • ECOG Performance Status 0-2
  • Patients must have received neoadjuvant chemotherapy in combination with trastuzumab with or without pertuzumab for a minimum of 12 weeks. All chemotherapy must have been completed preoperatively.
  • Patient must complete a minimum of 12 weeks of coverage with trastuzumab and a maximum of 24 weeks in the combined neoadjuvant and adjuvant setting prior to trial registration.
  • Administration of endocrine therapy for treatment of this breast cancer is allowed prior to trial registration.
  • Patient must register within 14 weeks of final surgery.
  • Adequate excision: surgical removal of all clinically evident disease in the breast and lymph nodes as follows:
      Breast surgery: total mastectomy with grossly negative margins (in the opinion of the surgeon there is no disease grossly at the margins) or breast-conserving surgery with histologically negative margins (no ink on tumor, including DCIS) unless those margins are anterior at the skin or posterior at the chest wall and no additional margin re-excision can be performed.
      Lymph node surgery: Lymph node surgery must have been performed and can include sentinel lymph node biopsy, targeted axillary dissection, or axillary dissection, at the discretion of the breast surgeon.
  • Adequate radiation: Patients who completed breast-conserving surgery (i.e. lumpectomy) must have received or plan to receive adjuvant radiation. If breast-conserving surgery was performed but patient will not be receiving breast radiation, the patient is not eligible.
  • No history of any prior (ipsi- or contralateral) invasive breast cancer. Prior DCIS is allowed.
  • No history of grade 3 or 4 toxicity related to trastuzumab. If pertuzumab is planned to be given on trial, patient must also have no history of grade 3-4 toxicity related to pertuzumab.

Please contact Legacy Oncology Research for additional study inclusion/exclusion information.
IRB Number Central IRB
Notes Study Details | NCT06876714 | ShortStop-HER2: 12 Months vs. 6 Months of HER2-targeted Medications for People With HER2+ Breast Cancer Who Had a Pathologic Complete Response After Chemotherapy Plus Trastuzumab | ClinicalTrials.gov
Principal Investigator Mei Dong, MD
Contact Name Oncology Clinical Research
Contact Phone 503-413-8199
Contact Fax 503-413-6920
Contact E-Mail oncologyresearch@lhs.org