AstraZeneca, Daiichi Drug Approved as New First-Line Therapy for Tough Type of Breast Cancer
Datroway (Datopotamab Deruxtecan) landed its third FDA approval in the past 18 months, this time as a treatment for triple negative breast cancer.The antibody drug conjugate was developed under a broad collaboration between Daiichi Sankyo and AstraZeneca.
A Daiichi Sankyo and AstraZeneca drug is now approved as a first-line treatment for a particularly difficult-to-treat type of breast cancer, bringing a new targeted therapy to patients that’s positioned at an advantage over a Gilead Sciences product from the same class of medicines.The FDA’s Friday regulatory decision for the drug, Datroway, covers the treatment of triple negative breast cancer (TNBC).It’s named for the lack of three receptors found in other types of breast cancer, which means that therapies for those targets won’t work.
Changing the Treatment Landscape
Chemotherapy is the first line of treatment for TNBC. The Merck immunotherapy Keytruda is also approved for this setting alongside chemotherapy.But not all TNBC patients are eligible for immunotherapy, which highlights the need for new treatment options.Datroway is an antibody drug conjugate (ADC) designed to target TROP2, a protein abundant on the surface of many cancer cells, including most triple negative breast cancers.
The FDA submission was based on Phase 3 results showing Datroway reduced the risk of disease progression or death by 43% compared to chemotherapy.For patients with metastatic TNBC who were not candidates for immunotherapy, Datroway led to median progression-free survival of 10.8 months compared to 5.6 months for the chemo arm;median overall survival was 23.7 months for Datroway-treated patients versus 18.7 months for those who received chemo.The objective response rate was 64% for the study drug versus 30% for chemotherapy.The clinical trial results were presented last fall during the European Society of Medical Oncology meeting.
Competitive Edge in the Market
The first TROP2-targeting ADC for TNBC was Gilead Sciences’ Trodelvy, approved in 2020 as a third-line or later treatment.Gilead aims to bring this drug into earlier lines of treatment.In patients ineligible for immunotherapy, Phase 3 results presented at the same ESMO meeting showed a 38% reduction in the risk of disease progression or death.The Gilead drug led to a median 9.7 month improvement in progression-free survival versus 6.9 months for the chemo arm;overall survival data were not yet mature.
For now, Datroway has the edge over Trodelvy in TNBC. This ADC was discovered and developed by Daiichi Sankyo.In 2019, the company began an alliance with AstraZeneca focused on Enhertu, a HER2-targeting ADC.The following year, AstraZeneca paid $1 billion up front to begin a collaboration on DS-1062, which became Datroway.Up to $5 billion more is tied to the achievement of regulatory and commercial milestones for Datroway, which has racked up three approvals in the past 18 months.
Datroway was first approved last year for HR positive and HER2 negative breast cancer and then for EGFR-mutated non-small cell lung cancer.The TNBC regulatory decision is an accelerated FDA approval based on the objective response rate the duration of response.Continued approval in this indication may require additional data from a confirmatory study.
