IMpassion131 finds combination leads to lower overall survival than placebo

WASHINGTON — The FDA issued an alert to patients, physicians, and oncology trial investigators warning that combination atezolizumab and paclitaxel was not effective in patients with previously untreated, inoperable, locally advanced or metastatic triple negative breast cancer (mTNBC).

This warning was based on results from IMpassion131, a phase III, multicenter, randomized, double-blind, placebo-controlled trial that pitted the combination against placebo in patients with mTNBC. According to the trial, atezolizumab and paclitaxel failed to significantly reduce the risk of cancer progression and death compared with placebo and paclitaxel in patients with PD-L1-positive tumors, and interim overall survival results favored paclitaxel and placebo over the combination in patients with and without PD-L1-positive tumors.

“Atezolizumab in combination with paclitaxel is not approved for use in breast cancer,” the FDA pointed out. “However, atezolizumab in combination with paclitaxel protein-bound (Abraxane)—a different combination therapy—is currently approved for the treatment of adult patients with mTNBC whose tumors express PD-L1, as determined by an FDA-approved test. Continued approval of atezolizumab in combination with paclitaxel protein-bound may be contingent on proven benefit of the treatment in additional trials.”

The FDA noted that it will continue to review the findings of IMpassion131 and “communicate new information regarding the IMpassion131 results and any potential changes to prescribing information. FDA is also evaluating the use of atezolizumab and paclitaxel in ongoing clinical trials for breast cancer and will recommend additional changes as appropriate.”

Despite this warning, the FDA noted that patients taking atezolizumab and paclitaxel for other approved uses should continue to take their medication as directed by their health care professional. The agency added that health care professionals and patients should report any adverse events or side effects related to the use of atezolizumab and paclitaxel to the FDA’s MedWatch reporting system.

John McKenna, Associate Editor, BreakingMED™

Cat ID: 22

Topic ID: 78,22,730,22,691,192,925