FDA Approves Second ADC for Breast Cancer From Daiichi Sankyo, AstraZeneca

The FDA recently approved a new antibody-drug conjugate (ADC) for the treatment of the most common form of breast cancer. While payers expect it to have some impact in their management of the condition, oncologists said they anticipate it having more of an impact on their prescribing, according to a Zitter Insights survey.

On Jan. 17, the FDA approved Daiichi Sankyo, Inc. and AstraZeneca’s Datroway (datopotamab deruxtecan-dlnk or Dato DXd) for the treatment of adults with unresectable or metastatic hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) breast cancer who have received endocrine-based therapy and chemotherapy for unresectable or metastatic disease. The agency used the Assessment Aid in its review of the Trop-2-directed antibody and topoisomerase inhibitor conjugate. The recommended dose is 6 mg/kg via intravenous infusion every three weeks, and the price of one 100 mg single-dose vial is $4,891.07.

The companies also collaborate on another ADC, Enhertu (fam-trastuzumab deruxtecan-nxki), which received an additional breast cancer indication on Jan. 27.

The National Cancer Institute estimates that there were 310,720 new cases of breast cancer in 2024. The HR+/HER2- subtype, it says, is the most common subtype, representing about 70% of people with breast cancer.

“Despite considerable progress in the HR-positive, HER2-negative metastatic breast cancer treatment landscape, new therapies are still needed to tackle the frequent and complex challenge of disease progression after endocrine and initial chemotherapy,” remarked Aditya Bardia, M.D., program director of breast oncology and director of translational research integration at the UCLA Health Jonsson Comprehensive Cancer Center, as well as the global principal investigator for the agent’s Phase III clinical trial, TROPION-Breast01. “The approval of datopotamab deruxtecan, a novel TROP2-directed antibody drug conjugate, marks a major therapeutic milestone and provides patients with metastatic breast cancer a new treatment alternative to conventional chemotherapy.”

For the Managed Care Oncology Index: Q1 2024, from Feb. 23, 2024, to March 12, 2024, Zitter Insights polled 35 commercial payers covering 115.3 million lives, 28 Medicare payers covering 44.7 million lives, 50 oncologists and 51 practice managers about their management and prescribing of breast cancer treatments.

AIS Health and Zitter Insights are both divisions of MMIT.

About one-third of all payers said they were somewhat aware of Datroway, including payers with 76% of Medicare covered lives. That compared with 52% of oncologists who similarly ranked their own knowledge of the ADC.

Exactly half of all payers — commercial payers covering 69% of lives and Medicare payers with 50% of lives — said they expected the new product to have some impact on their management of other agents that treat HER2- breast cancer, meaning that there will be no change in coverage or tiering, but some drugs’ utilization management criteria may be modified (see infographic).

However, 53% of oncologists said they expect the availability of Datroway to have a moderate impact on their treatment approach for people with HER2- breast cancer, meaning that they expect their prescribing will change for a considerable portion of patients.