Early-Phase Study of Cabozantinib Plus Atezolizumab in Advanced Triple-Negative Breast Cancer

By: Sarah Campen, PharmD
Posted: Monday, February 7, 2022

The phase Ib COSMIC-021 trial investigated the safety and efficacy of cabozantinib and atezolizumab in several advanced solid tumors—including triple-negative breast cancer, ovarian cancer, and endometrial cancer. Ira Winer, MD, PhD, of Karmanos Cancer Institute, Detroit, and colleagues presented the early clinical findings demonstrating clinical activity with the combination therapy at the 2021 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 531). The study was also published in the Journal for ImmunoTherapy of Cancer.

The tyrosine kinase inhibitor cabozantinib is suggested to enhance the activity of immune checkpoint inhibitors. In this study, women with locally advanced or metastatic triple-negative breast cancer (n = 30), ovarian cancer (n = 32), or endometrial cancer (n = 30)—whose disease had progressed on prior systemic therapy—received cabozantinib at 40 mg orally daily and atezolizumab at 1,200 mg intravenously every 3 weeks. Approximately one-half of patients had received two prior lines of therapy.

The treatment combination demonstrated “encouraging” clinical activity in each cohort. The objective response rate in the triple-negative breast, ovarian, and endometrial cancer cohorts was 17%, 19%, and 7%, respectively; the disease control rate in each tumor type was 67%, 63%, and 53%, respectively.

In all, grade 3 or 4 treatment-related adverse events occurred in 33% of patients with triple-negative breast cancer, 56% of those with ovarian cancer, and 37% of individuals with endometrial cancer. Two grade 5 treatment-related adverse events were reported: one pulmonary hemorrhage in the breast cancer cohort and one case of encephalitis in the ovarian cancer cohort.

Disclosure: No information regarding conflicts of interest was provided.

Journal for ImmunoTherapy of Cancer

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