What's Happening?
The U.S. Food and Drug Administration (FDA) has approved Enhertu (trastuzumab deruxtecan), developed by Daiichi Sankyo and AstraZeneca, for use as a first-line treatment for patients with HER2-positive breast cancer. This marks the first new first-line option
for this condition in over a decade. The approval is for patients with advanced-stage tumors that are inoperable or have metastasized, with a HER2 score of 3 or more. The decision follows the DESTINY-Breast09 study, which demonstrated a 44% reduction in progression-free survival (PFS) when Enhertu was used in combination with Roche's Perjeta (pertuzumab), compared to the traditional THP regimen. Enhertu has shown a median PFS of over three years, significantly longer than the two years observed with the THP regimen. However, the treatment is associated with a 12% incidence of interstitial lung disease (ILD), though most cases are manageable.
Why It's Important?
The approval of Enhertu as a first-line treatment option is significant for the medical community and patients with HER2-positive breast cancer, as it offers a new standard of care that could potentially improve survival rates. The drug's ability to extend progression-free survival by over a year compared to existing treatments represents a major advancement in cancer therapy. This development is also crucial for Daiichi Sankyo and AstraZeneca, as Enhertu is a key growth driver, with sales reaching $3.58 billion in the first nine months of the year. The approval could further boost the drug's market performance, potentially reaching the projected $5 billion in sales for 2025.
What's Next?
Following this approval, Daiichi Sankyo and AstraZeneca plan to expand the use of Enhertu into earlier stages of HER2-positive breast cancer. They are preparing regulatory filings based on the results of the DESTINY-Breast05 and DESTINY-Breast11 studies, which focus on 'post-neoadjuvant' and neoadjuvant settings. These efforts could further solidify Enhertu's role in breast cancer treatment and potentially lead to additional approvals for broader use in different stages of the disease.
