Primary completion for a Phase 3 study evaluating Trastuzumab Deruxtecan in previously treated advanced or metastatic HER2-positive breast cancer was reported on 2024-02-08. Key results included an objective response rate of 62.7% in patients without brain metastasis at baseline.
Background
The study investigated Trastuzumab Deruxtecan (T-DXd) in participants with advanced or metastatic HER2-positive breast cancer who had previously received anti-HER2-based regimens and experienced disease progression. The trial included patients who had received no more than two prior lines of therapy in the metastatic setting (excluding tucatinib), enrolling participants both with and without brain metastasis.
Trial design
The Phase 3 study (NCT04739761) enrolled 506 participants with breast cancer. This open-label, multicenter, international study assessed the efficacy and safety of Trastuzumab Deruxtecan. It included participants with previously-treated advanced or metastatic HER2-positive breast cancer, both with and without brain metastasis. Key outcome measurements were reported for Cohort 1 (without brain metastasis) and Cohort 2 (with brain metastasis).
Key results
- For Cohort 1 (without brain metastasis), the Objective Response Rate (ORR) was 62.7%.
- The Survival Rate at 12 Months for Cohort 1 was 90.6%.
- For Cohort 2 (with brain metastasis), the Objective Response Rate was 51.7%.
- The Progression-free Survival (PFS) Rate at 12 Months for Cohort 2 was 61.6%.
- The Survival Rate at 12 Months for Cohort 2 was 90.3%.
- The median Duration of Treatment on Subsequent Lines of Therapy was 4.4 Months for Cohort 1 and 6.5 Months for Cohort 2. An additional reported median Duration of Treatment on Subsequent Lines of Therapy for Cohort 1 was 3.0 Months.
What this means
The completion of this Phase 3 study provides further data on Trastuzumab Deruxtecan in advanced or metastatic HER2-positive breast cancer. Reported objective response rates of 62.7% (without brain metastasis) and 51.7% (with brain metastasis), alongside 12-month survival rates over 90% in both cohorts, suggest continued positive outcomes. These results are relevant for patients who have progressed on prior anti-HER2 therapies, indicating Trastuzumab Deruxtecan may offer a valuable treatment option, including for those with brain metastases.
Source
The information regarding the primary completion and key measurements of this trial was obtained from ClinicalTrials.gov. The data for the study NCT04739761, titled "A Study of T-DXd in Participants With or Without Brain Metastasis Who Have Previously Treated Advanced or Metastatic HER2 Positive Breast Cancer", was posted on 2024-02-08 on clinicaltrials.gov.