FDA Flags Safety Concerns for Oral Paclitaxel Plus Encequidar in Treatment of Breast Cancer
Posted: Wednesday, March 3, 2021
On March 1, the U.S. Food and Drug Administration (FDA) delivered a complete response letter to Athenex for the new drug application for oral paclitaxel plus encequidar in the treatment of patients with metastatic breast cancer. The FDA issued the letter to indicate that the review cycle for an application is complete and that the application is not ready for approval in its present form. Specially, the FDA noted its concern of safety risk with the use of oral paclitaxel compared with intravenous paclitaxel in terms of an increase in neutropenia-related sequelae.
The FDA also expressed concerns regarding the uncertainty over attainment of the primary endpoint in the clinical trial. The objective response rate at week 19 was conducted by a blinded independent central review. However, further analysis showed a potential unmeasured bias in this review reconciliation and re-read process.
The FDA recommends a new clinical trial testing the combination treatment in a patient population with metastatic breast cancer representative of the population in the United States. In addition, the FDA determined that additional risk-mitigation strategies to improve toxicity, which may involve dose optimization and/or exclusion of patients deemed to be at higher risk of toxicity, are required to support potential approval of the combination therapy in this patient population.
