ENHERTU Granted Breakthrough Therapy Designation in US

Daiichi Sankyo and AstraZeneca’s ENHERTU (fam-trastuzumab deruxtecan-nxki) has been granted breakthrough therapy designation (BTD) in the United States for the treatment of adult patients with unresectable or metastatic HER2 low (IHC 1+ or IHC 2+/ISH-negative) breast cancer. It is meant for those who have received a prior systemic therapy in the metastatic setting or developed disease recurrence during or within six months of completing adjuvant chemotherapy. Those with hormone receptor (HR) positive breast cancer should also have either received or be ineligible for endocrine therapy.

ENHERTU is being jointly developed and commercialized by Daiichi Sankyo and AstraZeneca. It is a specifically engineering HER2 directed antibody drug conjugate (ADC). The drug candidate demonstrated a statistically significant and clinically meaningful improvement in both progression-free survival (PFS) and overall survival (OS) versus the current standard of care, chemotherapy.

FDA’s BTD is meant to accelerate the development and regulatory review of new medicines that have the potential to treat serious conditions and address significant unmet medical needs. It is granted to medicines that have demonstrated substantial improvement on a clinically signific ant endpoint over available medicines.

“Historically, only patients with HER2 positive metastatic breast cancer were shown to benefit from HER2 directed therapy. DESTINY-Breast04, in which ENHERTU showed a clinically meaningful survival benefit in patients with HER2 low metastatic breast cancer, is the first trial to demonstrate that selecting patients for treatment based on low expression of HER2 has the potential to change the diagnostic and treatment paradigms for these patients,” said Ken Takeshita, MD, global head of R&D, Daiichi Sankyo, in a press release. “This Breakthrough Therapy Designation acknowledges the potential of ENHERTU to fulfill an unmet medical need and we look forward to working closely with the FDA to bring the first HER2 directed therapy to patients with metastatic breast cancer whose tumors have lower levels of HER2 expression.”

Source: Daiichi Sankyo