Combining hormone therapy with chemotherapy and HER2-targeted treatment before surgery for HER2+ breast cancer

Concurrent Neoadjuvant Chemo/Endocrine Therapy in HER2+ Breast Cancer

This trial will try giving hormone (endocrine) therapy at the same time as chemotherapy and HER2-targeted drugs for adults with HR+, HER2+ breast cancer to see if tumors respond better before surgery.

Quick facts

• Phase: PHASE2
• Study type: Interventional
• Enrollment: 30 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Legacy Health System (other)
• Drugs / interventions: chemotherapy
• Locations: 4 sites (Gresham, Oregon and 3 other locations)
• Trial ID: NCT07506876 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional trial gives concurrent endocrine therapy alongside standard neoadjuvant chemotherapy and HER2-directed therapy (TCHP) for adults with newly diagnosed HR+, HER2+ invasive breast cancer. Eligible patients are clinical stage IIA–IIIC and must have luminal A, luminal B, or HER2-enriched subtype by MammaPrint/BluePrint on the initial biopsy. Endocrine therapy may be started up to 28 days before enrollment and must be in place before the second cycle of chemotherapy, with a planned minimum of four cycles of TCHP. The main outcome is tumor response at the time of surgery (pathologic response) to determine if concurrent endocrine therapy increases treatment effect.

Who should consider this trial

Good fit: Adults (≥18) with newly diagnosed, previously untreated hormone receptor–positive, HER2+ invasive breast cancer, clinical stage IIA–IIIC, with luminal A/B or HER2-enriched subtype by MammaPrint/BluePrint, who plan to receive at least four cycles of TCHP are ideal candidates.

Not a fit: Patients with stage IV disease, recurrent breast cancer, recent non-breast cancers within two years, those under 18, pregnant, or whose tumor subtype does not meet the MammaPrint/BluePrint criteria are unlikely to receive benefit.

Why it matters

Potential benefit: If successful, this approach could increase tumor shrinkage before surgery, possibly allowing less extensive surgery and improving long-term outcomes.

How similar studies have performed: The idea of giving endocrine therapy concurrently with chemo and HER2-targeted agents is relatively novel—most prior neoadjuvant approaches give endocrine therapy after chemo/HER2 therapy and there are limited data showing clear benefit for concurrent use.

Eligibility criteria

Inclusion Criteria:

1. Adults over 18 years of age with newly diagnosed, previously untreated, HR+, HER2+ breast cancer (positive per local guidelines)

   1. Endocrine therapy for the current breast cancer may be started within 28 days prior to trial enrollment and must be initiated prior to C2 of chemotherapy/HER2 directed therapy
   2. Choice of endocrine therapy will be determined by the treating and/or enrolling physician
2. Anatomic Stage IIA - IIIC breast cancer planning a minimum of 4 cycles of TCHP
3. Patients must be Luminal A, Luminal B or HER2 enriched subtype on MammaPrint/BluePrint performed on initial biopsy

Exclusion Criteria:

1. Children under 18 years of age, pregnant women, prisoners, and decisionally impaired adults.
2. Patients with non-breast cancer within prior 2 years
3. Patients with breast cancer within prior 5 years
4. Patients with recurrent breast cancer
5. Patients with stage IV breast cancer

Where this trial is running

Gresham, Oregon and 3 other locations

• Legacy Mount Hood Medical Center — Gresham, Oregon, United States (RECRUITING)
• Legacy Good Samaritan Medical Center — Portland, Oregon, United States (RECRUITING)
• Legacy Meridian Park Medical Center — Tualatin, Oregon, United States (RECRUITING)
• Legacy Salmon Creek Medical Center — Vancouver, Washington, United States (RECRUITING)

Conditions: Breast Cancer - Infiltrating Ductal Carcinoma, HER-2 Positive Breast Cancer