Gilead Reports Promising Phase 3 Results for Trodelvy and Keytruda in Aggressive Breast Cancer

Gilead Sciences has reported encouraging findings from a phase 3 clinical trial evaluating the efficacy of its antibody-drug conjugate, Trodelvy (sacituzumab govitecan-hziy), in combination with Merck & Co’s anti-PD-1 therapy, Keytruda (pembrolizumab). This study focuses on patients with triple-negative breast cancer (TNBC), a particularly aggressive form of the disease.

The trial, named ASCENT-04/KEYNOTE-D19, successfully achieved its primary goal. It demonstrated that the combination of Trodelvy and Keytruda significantly enhanced progression-free survival in patients compared to traditional treatment with Keytruda and chemotherapy. This study involved patients with unresectable locally advanced or metastatic TNBC, specifically those whose tumors express the protein PD-L1.

While the primary endpoint showed clear benefits, there was also an early indication of improved overall survival, which was a secondary endpoint of the study. However, these data were still immature at the time of analysis, and further monitoring is planned to assess this trend more thoroughly.

In terms of safety, the combination treatment's profile was consistent with what is known about each drug individually, with no new safety concerns emerging from the study.

TNBC represents about 15% of all breast cancer cases and is usually more common in younger, premenopausal women. This type of breast cancer is notoriously aggressive and has been challenging to treat, with a higher risk of recurrence and metastasis compared to other forms of breast cancer. Despite recent advancements, treatment options for first-line metastatic TNBC with PD-L1 expression have been limited.

Dietmar Berger, Chief Medical Officer at Gilead, expressed optimism about the study's findings. He emphasized that this is the first evidence showcasing the potential of combining an antibody-drug conjugate with an immuno-oncology agent in early treatment lines for metastatic breast cancer. Berger suggested that this combination could pave the way for redefining treatment pathways for patients with this challenging type of breast cancer.

The collaboration between Gilead and Merck, known as MSD outside the United States and Canada, began in 2021, aiming to explore the potential of the Trodelvy and Keytruda combination in treating TNBC. The detailed results of the trial are slated for presentation at an upcoming medical conference and will be discussed with regulatory bodies to explore potential approvals.

Dr. Sara Tolaney from the Dana-Farber Cancer Institute, who served as the primary investigator for the study, highlighted the significance of the findings. She noted that the combination of Trodelvy and Keytruda may represent a new treatment strategy by merging a potent antibody-drug conjugate with immunotherapy to potentially improve patient outcomes.

The positive results from ASCENT-04/KEYNOTE-D19 offer hope for patients battling this difficult-to-treat form of breast cancer, suggesting a new pathway that could potentially redefine their treatment options in the future.