FDA Alert: Efficacy Concerns with Atezolizumab Plus Paclitaxel for Breast Cancer

Officials with the FDA have issued a safety alert about the potential efficacy and safety concerns with atezolizumab (Tecentriq) in combination with paclitaxel for the treatment of breast cancer.

According to the alert, which was issued on September 8, results from a clinical trial studying the use of atezolizumab and paclitaxel in patients with previously untreated inoperable locally advanced or metastatic triple negative breast cancer (mTNBC) showed the drug combination did not work to treat the disease.

The phase 3 study, IMpassion131, evaluated atezolizumab in combination with paclitaxel compared with placebo and paclitaxel for patients with mTNBC. According to the results, the combination therapy did not significantly reduce the risk of cancer progression and death compared with placebo and paclitaxel in the PD-L1-positive population. In addition, interim overall survival results favored paclitaxel plus placebo over paclitaxel plus atezolizumab in both the PD-L1-positive population and total population.

Although atezolizumab plus paclitaxel is not approved in this indication, atezolizumab in combination with paclitaxel protein-bound (Abraxane) is currently used for the treatment of adult patients with mTNBC whose tumors express PD-L1. Continued approval of atezolizumab plus paclitaxel protein-bound may be contingent on proven benefit of the treatment in additional trials. The FDA urged that health care professionals should not replace paclitaxel protein-bound with paclitaxel in clinical practice.

The agency will review the findings from the IMpassion131 trial and further communicate new information regarding the results and any potential changes to prescribing information. The FDA is also evaluating the use of atezolizumab and paclitaxel in ongoing clinical trials for breast cancer, and will recommend additional changes as appropriate. Patients who are taking the combination therapy for other approved uses should continue to take their medication as directed by their health care professional.

Reference

FDA alerts health care professionals and oncology clinical investigators about efficacy and potential safety concerns with atezolizumab in combination with paclitaxel for the treatment of breast cancer. Drug Safety and Availability. FDA; September 8, 2020. Accessed September 11, 2020. https://www.fda.gov/drugs/drug-safety-and-availability/fda-alerts-health-care-professionals-and-oncology-clinical-investigators-about-efficacy-and​