FDA Committee Votes to Delay Approval Decision on Keytruda in Early TNBC Until More Data is Available

The Food and Drug Administration’s Oncologic Drugs Advisory Committee unanimously voted in favor of waiting for more data before making an approval decision involving the use of Keytruda in early triple-negative breast cancer.

The Food and Drug Administration (FDA) has issued a complete response letter to Merck, the manufacturer of Keytruda (pembrolizumab), regarding an application for the approval of the anti-PD-1 inhibitor as treatment in combination with chemotherapy in the neoadjuvant (before surgery) setting and as a monotherapy in the adjuvant (after surgery) setting for patients with high-risk early-stage triple-negative breast cancer.

The letter — which indicates the FDA has completed its review of available data — comes on the heels of the FDA’s Oncologic Drugs Advisory Committee voting 10 to 0 in favor of pushing back a regulatory decision until more data are available.

Merck notes that it is reviewing the letter to ensure that next steps can be reviewed with guidance from the FDA.

Of note, the letter from the FDA does not affect any current indications for Keytruda, which includes its use with chemotherapy in patients with locally recurrent unresectable or metastatic triple-negative breast cancer with a PD-L1 expression.

The application for approval was backed by results from the phase 3 KEYNOTE-522 trial, which enrolled 1,174 patients to assess pathological complete response and event-free survival. Patients were randomized 2:1 to either receive Keytruda plus chemotherapy or placebo plus chemotherapy in the neoadjuvant setting, followed by Keytruda or placebo as a single therapy in the adjuvant setting.

Patients in the Keytruda group achieved a pathological complete response rate of 64.8% compared to 51.2% in the placebo group. The trial is still evaluating other measures, including event-free survival, which is what led to a recommendation in delaying the regulatory decision on the drug.

The FDA was originally expected to decide on the approval of the combination by the end of March. The next analysis of the data from the KEYNOTE-522 trial is expected at the end of the third quarter of 2021, Merck announced.

A version of this article originally appeared on CancerNetwork® as, “FDA Issues Complete Response Letter for Pembrolizumab as Neoadjuvant Therapy in Early TNBC.”

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