AstraZeneca, Daiichi Sankyo Drug Wins Landmark US Approval
Enhertu, a potent antibody-drug conjugate, receives FDA nod as a first-line treatment for metastatic HER2-positive breast cancer, poised to become a new standard of care.
Shares in AstraZeneca PLC (NASDAQ: AZN) climbed Tuesday after the U.S. Food and Drug Administration granted a landmark approval for Enhertu, a cancer therapy co-developed with Japan’s Daiichi Sankyo, for a new, broader use in patients with an advanced form of breast cancer.
The expanded approval positions Enhertu as a first-line treatment for adult patients with unresectable or metastatic HER2-positive breast cancer. AstraZeneca's U.S.-listed shares rose 1.93% to $91.56 in afternoon trading, reflecting investor optimism over the drug's expanded market potential.
The FDA's decision, granted under its Priority Review and Breakthrough Therapy Designation programs, marks the first new first-line treatment option in over a decade for this patient population. The approval specifically covers patients who have received a prior anti-HER2-based regimen, significantly widening the drug's reach.
The regulatory green light was based on the strength of the Phase III DESTINY-Breast09 trial. Data from the study showed that Enhertu, when used in combination with another therapy, demonstrated a "statistically significant and clinically meaningful improvement" in progression-free survival. According to the company's announcement, the regimen reduced the risk of disease progression or death by 44% compared to the standard of care.
Enhertu is a precisely engineered antibody-drug conjugate (ADC), a class of therapy that links a potent cancer-killing agent directly to a monoclonal antibody, which then targets specific cancer cells. This mechanism allows for a powerful therapeutic effect while minimizing damage to healthy cells.
This approval is expected to cement Enhertu's status as a blockbuster drug for the partnered companies. Prior to this decision, some analysts had already projected Enhertu's peak annual sales could approach $14.3 billion. By securing a position in the first-line setting, the drug is now placed to capture a larger share of the more than $1.6 billion U.S. market for HER2-positive breast cancer treatment.
The clinical community has reacted positively, with some suggesting the drug could transform patient outcomes. Dr. Sara Tolaney of the Dana-Farber Cancer Institute noted the regimen "should become a new 1st-line standard of care," as reported by multiple outlets.
"This approval has the practice-changing potential to redefine the treatment of patients with HER2-positive metastatic breast cancer," said Ken Keller, Global Head of Oncology Business and President and CEO of Daiichi Sankyo, Inc.
The successful collaboration between AstraZeneca, a British-Swedish pharmaceutical giant with a $278 billion market capitalization, and Tokyo-based Daiichi Sankyo has yielded one of the most promising assets in the oncology pipeline. The FDA's official approval letter formalizes Enhertu's role in earlier stages of treatment, promising to improve the prognosis for thousands of patients annually and fuel revenue growth for both developers in the highly competitive cancer therapy market.