T-DXd plus RT shows promise in management of metastatic breast cancer

Combination treatment with trastuzumab deruxtecan (T-DXd) and radiation therapy (RT) may improve clinical outcomes, without compromising safety, in patients with HER2-positive and HER2-low metastatic breast cancer, reveals a study.

Researchers performed a retrospective study in patients treated between November 2020 and January 2024 and identified those with HER2-positive and HER2-low metastatic breast cancer who received concurrent T-DXd and RT. They obtained data on demographics, treatment regimens, radiation doses, toxicity profiles, efficacy, and treatment discontinuations. Toxicities were graded using CTCAE V5.0.

Overall, 33 patients with HER2-positive and HER2-low metastatic breast cancer who underwent both T-DXd and RT were included in the analysis, with a median follow-up of 14 months.

Partial remissions occurred in 39.4 percent of patients and complete remission in 9.4 percent. Furthermore, 39.4 percent of patients had a stable disease, while 12.1 percent experienced disease progression, which required a change in therapy.

In terms of safety, the researchers observed significant associations between acute toxicities and systemic treatment. In survival analysis, 11 deaths (33.3 percent) occurred during the follow-up period, with a median overall survival of 26 months, and a median progression-free survival of 12 months.

“Further studies are warranted to fully elucidate the potential synergistic effects of this treatment regimen and its impact on patient outcome,” the researchers said.