Enhertu Achieves Statistically Significant OS Benefit in DESTINY-Breast03 Trial

On December 7, 2022, AstraZeneca announced the results of an interim analysis from the DESTINY-Breast03 Phase 3 clinical trial. The trial evaluated the efficacy and safety of Enhertu (Trastuzumab deruxtecan) compared to T-DM1 (Kadcyla) in patients with HER2-positive metastatic breast cancer who had been previously treated.

Study Design: DESTINY-Breast03 Trial

The trial randomized 524 patients with HER2-positive metastatic breast cancer in a 1:1 ratio:

1. Enhertu Group (N=261)
2. T-DM1 Group (N=263)

The primary endpoint was progression-free survival (PFS), which was previously reported as being significantly improved with Enhertu. This interim analysis focused on secondary endpoints, including overall survival (OS).

Key Survival Results

With a median follow-up of 28.4 months for Enhertu and 26.5 months for T-DM1:

• Overall Survival (OS): Neither group had reached the median OS at the time of analysis.
• 2-Year OS Rate: 77.4% for the Enhertu group vs. 69.9% for the T-DM1 group.
• Consistent Benefit: The OS benefit was observed across all analyzed subgroups, including patients with or without brain metastases, those with different hormone receptor statuses, and those with prior treatment history (e.g., Pertuzumab).

Conclusion

Dr. Sara Hurvitz noted that these results further solidify Enhertu as a transformative treatment. For patients with HER2-positive metastatic breast cancer, Enhertu provides a clinically meaningful and statistically significant improvement in overall survival compared to the previous standard of care, T-DM1.

Source: AstraZeneca Press Release - Enhertu Overall Survival Results

#BreastCancer #HER2Positive #Enhertu #TDXd #DESTINYBreast03 #OverallSurvival #CancerResearch

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