FDA Approves AstraZeneca, Daiichi Sankyo ADC for Advanced Breast Cancer

AstraZeneca, in collaboration with Daiichi Sankyo, has achieved a significant milestone with the FDA approval of a new targeted therapy for certain advanced breast cancer cases. This new treatment, Datroway, represents a promising addition to AstraZeneca's oncology portfolio, a critical component of the company's growth strategy.

The FDA's approval allows Datroway to be used in adults with advanced HR-positive, HER2-negative breast cancer that is inoperable and has progressed despite endocrine-based therapy and chemotherapy. Datroway, previously known as datopotamab deruxtecan or Dato-DXd during its development, is classified as an antibody-drug conjugate (ADC). These therapies work by attaching a potent chemotherapy agent to a targeting antibody. Datroway specifically targets TROP2, a protein prevalent on cancer cells, including those in breast cancer.

The evaluation of Datroway's efficacy and safety was conducted through a Phase 3 clinical trial involving 732 patients with advanced breast cancer. Participants were randomly divided to receive either Datroway or traditional chemotherapy. The primary objectives were to assess progression-free survival and overall survival. Results indicated that patients in the Datroway group had a median progression-free survival of 6.9 months, compared to 4.9 months for those on chemotherapy, a statistically significant improvement. However, Datroway did not achieve statistical significance in overall survival, showing a median of 18.6 months versus 18.3 months for chemotherapy participants.

AstraZeneca already offers another ADC for breast cancer treatment, Enhertu, which received its initial FDA approval in 2019 for HER2-positive breast cancer. Enhertu's application has since widened to include HER2-low metastatic breast cancer and HER2-positive non-small cell lung cancer. Last year, the FDA further expanded its use to treat solid tumors expressing HER2, regardless of their location in the body. AstraZeneca aims to introduce at least 20 new medicines by 2030, with a goal to elevate annual revenue to $80 billion. Datroway represents the eighth new medication in pursuit of this objective.

Dave Fredrickson, AstraZeneca’s executive vice president of the oncology hematology business unit, stated that Datroway's approval in the U.S. marks a continuation of their commitment to improve cancer treatment through ADCs, potentially replacing conventional chemotherapy for several cancers.

According to Citeline, a biopharma information services firm, Datroway is among the anticipated key drug launches for 2025. The Phase 3 results are reportedly similar to Trodelvy, another TROP2-targeting ADC from Gilead Sciences, used as a second-line treatment for HR-positive, HER2-negative breast cancer. However, Datroway’s performance does not match the level of Enhertu.

The Citeline report also highlighted a treatment-related death in the Datroway trial. For patients with advanced breast cancer who have alternative treatments available, potential safety concerns might make physicians more cautious about prescribing Datroway. As such, Datroway is expected to gain only a modest market share.

Beyond the U.S., AstraZeneca has submitted Datroway for regulatory review in Europe, China, and other regions. The company is also working to expand Datroway’s application to other cancer types. Recently, the FDA accepted an application for the drug as a treatment for EGFR-mutated non-small cell lung cancer, with a regulatory decision anticipated in the third quarter of this year.