NCT06361940

Molecular Analyses to Predict Pathways of Endocrine Resistance Following Short Term Neoadjuvant Endocrine Treatment in Patients With Hormone Receptor-Positive HER2-negative Breast Cancer

Molecular Analyses to Predict Pathways of Endocrine Resistance Following Short Term Neoadjuvant Endocrine Treatment in Patients With Hormone Receptor-Positive HER2-negative Breast Cancer (MAPPER)

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 100 (estimated)
• Sponsor: Medical College of Wisconsin · Academic / Other
• Sex: Female
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This is an exploratory phase II interventional study that initiates standard-of-care anti-estrogen treatment preoperatively for 4-12 weeks (+/- 2 weeks).

Detailed description

Patients with HR+ HER2- node-negative breast cancers generally undergo surgical resection upfront, followed by adjuvant chemotherapy, if needed, in addition to adjuvant endocrine therapy. Because endocrine therapy is primarily delivered in the postoperative setting, the ability to assess the tumor response to this treatment modality is lost and very difficult to assess. This study offers the unique opportunity to assess the responsiveness of breast tumors to endocrine therapy while the tumors are still in vivo by treating patients with endocrine therapy before surgery and assessing molecular changes with treatment. By comparing pre- and post-treatment levels of molecular markers with advanced omic analysis in individual tumors, the investigators expect to identify predictors of responsiveness to existing agents and identify new candidate therapeutic targets.

Conditions

• Breast Cancer

Interventions

Type	Name	Description
DRUG	Aromatase inhibitors or tamoxifen	Choice of endocrine therapy (aromatase inhibitors or tamoxifen) would be decided by medical oncologist, following a review of the patient's medical history and menstrual status.

Timeline

• Start date: 2024-09-30
• Primary completion: 2028-12-01
• Completion: 2029-12-01
• First posted: 2024-04-12
• Last updated: 2025-10-14

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study