Trial results for Trastuzumab Deruxtecan (Enhertu) in the Phase 2 DS-8201a study (NCT04420598) were posted on ClinicalTrials.gov on 2025-06-24. The study investigated the drug in advanced HER2-positive breast cancer with brain metastases, reporting a median overall survival of 13.3 months in Cohort 5.
Background
The DS-8201a study investigated trastuzumab deruxtecan for patients with Advanced Breast Cancer, HER2-positive Breast Cancer, Brain Metastases, and Leptomeningeal Metastasis.
Trial design
The DS-8201a study (NCT04420598) was a Phase 2, multicenter, international, open-label, single-arm, multicohort clinical trial that enrolled 41 participants. The trial investigated trastuzumab deruxtecan in patients with Advanced Breast Cancer, HER2-positive Breast Cancer, Brain Metastases, and Leptomeningeal Metastasis. The study utilized a two-stage optimal Simon's design.
Key results
Key results from the trial include:
- For 16-week Progression-Free Survival (PFS) per Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) in Cohort 1, 1 out of 7 participants achieved this outcome.
- For Objective Response Rate (ORR) according to RANO-BM:
- In Cohort 2, 3 out of 7 participants achieved an objective response.
- In Cohort 3, 4 out of 5 participants achieved an objective response.
- In Cohort 4, 3 out of 3 participants achieved an objective response.
- The median Overall Survival (OS) in Cohort 5 was 13.3 months.
- For Intra-cranial Evaluation according to RANO-BM:
- 2 participants in Cohort 1 had this evaluation.
- 0 participants in Cohort 2 had this evaluation.
- 0 participants in Cohort 3 had this evaluation.
What this means
The posted results from the Phase 2 DS-8201a trial provide initial data on trastuzumab deruxtecan in advanced HER2-positive breast cancer patients with brain metastases. The objective response rates observed in Cohorts 2, 3, and 4, particularly the 3 out of 3 participants in Cohort 4, suggest activity in this challenging patient population. The median overall survival of 13.3 months in Cohort 5 offers an indication of potential clinical benefit. These findings contribute to the understanding of trastuzumab deruxtecan's profile in patients 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 NCT04420598, titled "DS-8201a for trEatment of aBc, BRain Mets, And Her2[+] Disease," were posted on 2025-06-24 on clinicaltrials.gov.