NCT06446882

Diagnostic HER2DX-guided Treatment for Patients wIth Early-stage HER2-positive Breast Cancer

Diagnostic HER2DX-guided Treatment for patIents wIth Early-stage HER2-positive Breast Cancer

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 304 (estimated)
• Sponsor: Fundacio Clinic Barcelona · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The primary goal of the DEFINITIVE trial is to demonstrate the effectiveness of the HER2DX diagnostic assay in enhancing the management of patients with early-stage HER2- positive breast cancer. Patients randomized to arm A will receive adjuvant treatment by physician´s choice, blinded to the diagnostic HER2DX test results. Patients randomized to Arm B will receive personalized treatment according to HER2DX results.

Detailed description

This is an international, multicenter, prospective, randomized, two-arm, open-label, phase III study to evaluate the HRQoL, safety, efficacy, and economical costs of using HER2DX in patients with stage II to IIIA HER2-positive breast cancer, suitable for neoadjuvant therapy. A dual primary endpoint with an according multiple testing procedure is defined in this study. First, the study will evaluate superiority in quality of life using i) the GHS scale from the EORTC QLQ-C30 questionnaire version 3.0 and ii) the score from the FACIT Fatigue Scale.

Conditions

• HER2-positive Breast Cancer
• Early-stage Breast Cancer

Interventions

Type	Name	Description
DEVICE	Personalized treatment according to molecular diagnosis with HER2DX	Patients with HER2DX high-risk disease: * Neoadjuvant treatment: * High HER2DX pCR score: paclitaxel per 12 weeks + trastuzumab +/- pertuzumab per 4-5 cycles. * Medium HER2DX pCR score: carboplatin + paclitaxel per 12-18 (or docetaxel per 4-6 cycles) + trastuzumab +/- pertuzumab per 4-7 cycles. * Low HER2DX pCR score: standard of care neoadjuvant CT regimens and HER2 blockade at the investigator's choice. * Adjuvant treatment: * pCR at surgery; Trastuzumab +/- pertuzumab up to a total of 18 cycles (including neoadjuvant and adjuvant therapy). * No pCR at surgery: T-DM1 per 14 cycles. Patients with HER2DX low-risk disease: * Neoadjuvant treatment: paclitaxel per 12 weeks + trastuzumab +/- pertuzumab per 4-5 cycles. * Adjuvant treatment will be according to the pCR status at surgery: * pCR at surgery: trastuzumab or no adjuvant treatment. * No pCR at surgery: trastuzumab or T-DM1.
OTHER	Treatment by physician´s choice, blinded to the diagnostic HER2DX test results	Patients randomized in ARM A will be treated with standard of care neoadjuvant CT regimens and HER2 blockade at the investigator's choice validated by national and/or international guidelines.

Timeline

• Start date: 2024-10-11
• Primary completion: 2028-11-01
• Completion: 2028-11-01
• First posted: 2024-06-06
• Last updated: 2026-02-20

Locations

29 sites across 5 countries: Austria, France, Israel, Italy, Spain