Trial results for trastuzumab deruxtecan (T-DXd) in participants with previously treated advanced or metastatic HER2-positive breast cancer were posted on ClinicalTrials.gov on 2025-05-16. The study showed an objective response rate of 62.7% in patients without brain metastasis and 51.7% in those with brain metastasis at baseline.
Background
This study investigated trastuzumab deruxtecan in participants with advanced or metastatic HER2-positive breast cancer. All participants had previously received anti-HER2-based regimens and had progressed, with no more than two prior lines of therapy in the metastatic setting (excluding tucatinib).
Trial design
The study (NCT04739761) was an open-label, multicenter, international Phase 3 trial. it enrolled 506 participants with breast cancer, specifically those with previously treated advanced or metastatic HER2-positive disease. The study assessed the efficacy and safety of trastuzumab deruxtecan in participants both with and without brain metastasis at baseline.
Key results
The trial reported several key outcome measurements for trastuzumab deruxtecan:
- In Cohort 1, which included participants without brain metastasis at baseline, the Objective Response Rate (ORR) was 62.7% (Percentage of participants).
- For Cohort 2, consisting of participants with brain metastasis at baseline, the Objective Response Rate (ORR) was 51.7% (Percentage of participants).
- The Progression-free Survival (PFS) Rate at 12 Months in Cohort 2 was 61.6% (Percentage of participants).
- The Survival Rate at 12 Months was 90.6% (Percentage of Participants) for Cohort 1 and 90.3% (Percentage of Participants) for Cohort 2.
- The median Duration of Treatment on Subsequent Lines of Therapy was 4.4 months for Cohort 1 and 6.5 months for Cohort 2.
What this means
The results from this Phase 3 study indicate that trastuzumab deruxtecan demonstrates substantial objective response rates in patients with previously treated advanced or metastatic HER2-positive breast cancer, both with and without brain metastasis. The high 12-month survival rates in both cohorts suggest a meaningful clinical benefit for this patient population. These findings support the potential of trastuzumab deruxtecan as an effective treatment option for these challenging cases, including those with central nervous system involvement.
Source
The information for these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for 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," were posted on 2025-05-16 on clinicaltrials.gov.