IMpassion050 Trial: Combining Standard of Care With Immunotherapy for High-Risk Breast Cancer

By: Kayci Reyer
Posted: Monday, October 17, 2022

According to research presented in the Journal of Clinical Oncology, atezolizumab with neoadjuvant dose-dense doxorubicin/cyclophosphamide/paclitaxel may not result in improved clinical outcomes for some patients with breast cancer. Primary findings from the phase III IMpassion050 study suggest that pertuzumab/trastuzumab plus chemotherapy, the current standard of care, may result in higher rates of pathologic complete response for patients with high-risk, HER2-positive early breast cancer.

“[Pertuzumab/trastuzumab] and chemotherapy remains standard of care; longer follow-up may help to inform the long-term impact of atezolizumab,” concluded Jens Huober, MD, of Cantonal Hospital, Lucerne, Switzerland, and colleagues.

The study included 454 patients who were randomly assigned to receive either placebo (n = 228) or atezolizumab (n = 226). Each group received neoadjuvant dose-dense doxorubicin/cyclophosphamide followed by paclitaxel plus pertuzumab/trastuzumab.

At the clinical cutoff in February 2021, the rates of pathologic complete response were comparable between the groups, at 62.7% in the placebo arm and 62.4% in the atezolizumab arm. The gap between response rates widened when evaluating only patients with PD-L1–positive tumors in the placebo (72.5%) and atezolizumab (64.2%) groups.

All grade 5 adverse events (n = 5) occurred in the atezolizumab group. The atezolizumab group also experienced more grade 3 or 4 and serious adverse events. These outcomes are consistent with the safety profile of atezolizumab as understood from previous combination studies.

“Longer follow-up of IMpassion050 is required to inform the long-term role of cancer immunotherapy, such as atezolizumab, in this setting,” concluded the investigators.

Disclosure: For full disclosures of the study authors, visit ascopubs.org.

Journal of Clinical Oncology

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