AstraZeneca and Daiichi Sankyo’s Enhertu (trastuzumab deruxtecan), for treating adults with unresectable or metastatic HER2-positive breast cancer, has landed approval from the US Food and Drug Administration (FDA).
It is intended for patients who have received a prior anti-HER2-based regimen either in the metastatic setting or in the neoadjuvant or adjuvant setting and have developed disease recurrence during or within six months of completing therapy.
Enhertu is a specifically engineered HER2-directed antibody-drug conjugate (ADC) being jointly developed and commercialized by the two pharmaceutical companies.
The FDA approval is based on positive results from the DESTINY-Breast03 Phase III trial that reportedly showed the treatment reduced the risk of disease progression or death by 72% versus trastuzumab emtansine (T-DM1) (hazard ratio [HR] 0.28; 95% confidence interval [CI]: 0.22-0.37; p<0.0001) in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane.
The approval, granted under the FDA’s Real-Time Oncology Review (RTOR) program, converts the accelerated approval of Enhertu in later line HER2-positive metastatic breast cancer to standard approval, broadening Enhertu’s breast cancer indication in the US to earlier lines of use in patients with HER2-positive metastatic breast cancer.
Erika Hamilton, director of the Breast Cancer and Gynecological Cancer Research Program for Sarah Cannon Research Institute, Nashville, Tennessee, said, “Enhertu has demonstrated significant progression-free survival in the earlier metastatic setting, potentially establishing it as a new standard of care in previously treated patients with HER2-positive metastatic breast cancer. Today’s approval is an important milestone for the clinical community as we will now be able to offer Enhertu to these patients earlier in their treatment.”
Catherine Ormerod, executive vice president of strategy and mission with Living Beyond Breast Cancer, said, “This is an important day for the breast cancer community. With this approval, Enhertu now provides a new treatment option for patients with HER2-positive metastatic breast cancer which can be used earlier in treatment to potentially delay the progression of the disease.”
Dave Fredrickson, executive vice president of AstraZeneca’s Oncology Business Unit, commented, “Enhertu is already established in the later-line treatment of patients with HER2-positive metastatic breast cancer, and we are thrilled that with this approval, patients in the US will now be able to access the transformative potential of Enhertu earlier in their treatment. We look forward to bringing this important, potentially paradigm-shifting medicine to even more patients across the globe in an earlier setting as quickly as possible.”
Finally, Ken Keller (Daiichi Sankyo’s global head of oncology business, president, and CEO), remarked, “Today’s FDA approval, which converts the accelerated approval of Enhertu to regular approval, highlights the importance of the FDA’s accelerated pathway that allows for earlier approval of medicines to treat serious medical conditions such as breast cancer. Data from DESTINY-Breast03 not only confirmed the results of DESTINY-Breast01, but also demonstrated the superiority of Enhertu in prolonging progression-free survival compared to T-DM1 in an earlier setting of HER2-positive metastatic breast cancer.”
The DESTINY-Breast03 Phase III trial results have been published online in The New England Journal of Medicine. In the study, Enhertu’s safety profile Enhertu was consistent with previous clinical trials, with no new safety concerns identified and no Grade 4 or 5 treatment-related interstitial lung disease events.