- Gilead has secured an expanded U.S. approval for its breast cancer medicine Trodelvy, announcing Friday the Food and Drug Administration cleared the antibody treatment for the most commonly occurring form of the tumor type.
- Previously approved only for rarer, “triple-negative” breast tumors, Trodelvy can now be used to treat patients with metastatic breast cancer that’s hormone receptor, or HR, positive, but negative for a protein called HER2. This type of breast cancer accounts for an estimated 70% of all new cases, according to Gilead.
- The FDA’s decision is a win for Gilead, which gained Trodelvy when it paid $21 billion to acquire Immunomedics in 2020. But clinical trial results showed the drug’s benefit was modest, and Gilead will face competition from a rival drug sold by AstraZeneca and Daiichi Sankyo.
Gilead’s acquisition of Immunomedics was the centerpiece of executives’ plans to make the biotechnology company, long known for its HIV and hepatitis C drugs, a competitor in oncology. So far, however, analysts have been skeptical of how that plan has unfolded, as Gilead has hit some setbacks and Trodelvy has been outshone by AstraZeneca and Daiichi’s Enhertu.
Friday’s approval is a step forward, significantly widening the market for Trodelvy. The FDA’s clearance is specifically for patients with HR-positive, HER2-negative breast cancer that’s either metastasized or can’t be removed through surgery. Eligible patients must have previously received a hormone therapy and at least two other systemic treatments in the metastatic setting.
According to Gilead executives, about 6,000 U.S. patients fit that description and the company has been preparing ahead of the FDA’s decision to start reaching out to doctors about the drug’s new use.
Approval is based on a study called TROPiCS-02, which enrolled just under 550 patients and showed treatment with Trodelvy helped delay cancer progression as well as modestly lengthened survival. Patients treated with Gilead’s drug in the study lived a median of 14.4 months following their enrollment, compared to 11.2 months for those who received another round of chemotherapy.
That benefit is not as large as AstraZeneca and Daiichi have shown with Enhertu, which is approved in the U.S. for breast cancers that are considered HER2 “low,” a new classification that encompasses many patients whose tumors would previously have been considered HER2-negative.
Trodelvy carries a safety warning for severe neutropenia and diarrhea.
Shares in Gilead rose 4% on news of the approval Friday morning.