FDA Grants Trastuzumab Deruxtecan Breakthrough Therapy Designation for Treatment of Unresectable or Metastatic HER2-Positive Breast Cancer

The FDA has granted trastuzumab deruxtecan (Enhertu, AstraZeneca/Daiichi Sankyo) Breakthrough Therapy Designation (BTD) in the United States for the treatment of adult patients with unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer who have received 1 or more prior anti-HER2-based regimens.

The designation was based on data from the DESTINY-Breast03 phase 3 trial, and this is now the second BTD for trastuzumab deruxtecan in breast cancer, bringing its total number of BTDs to 4, according to an AstraZeneca press release.

“This is an important step in bringing Enhertu as a potential new option in earlier lines of treatment for HER2-positive metastatic breast cancer, given the urgent need to improve outcomes,” said Susan Galbraith, executive vice president of oncology R&D at AstraZeneca, in the press release. “This recognition by the FDA underscores the transformative possibility of Enhertu seen with the remarkable DESTINY-Breast03 results presented at ESMO just two weeks ago.”

The DESTINY-Breast03 trial demonstrated a 72% reduction in the risk of disease progression or death compared to T-DM1 in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab and a taxane. The safety profile was consistent with previous clinical trials, with no new safety concerns identified and no grade 4 or 5 treatment-related interstitial lung disease events, according to the press release.

Trastuzumab deruxtecan is approved for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received 2 or more prior anti-HER2-based regimens in the metastatic setting in the United States, Japan, the EU, and other countries. It is being further looked at in a comprehensive clinical development program that evaluates the efficacy and safety across multiple HER2-targetable cancers, including breast, gastric, lung, and colorectal cancers.

REFERENCE

Enhertu granted Breakthrough Therapy Designation in US for patients with HER2-positive metastatic breast cancer treated with one or more prior anti-HER2-based regimens. AstraZeneca. October 4, 2021. Accessed October 4, 2021. https://www.astrazeneca.com/media-centre/press-releases/2021/enhertu-granted-btd-for-breast-cancer.html