- Athenex (NASDAQ:ATNX) slumps 22% premarket before trading was halted in reaction to receiving a complete response letter (CRL) from the FDA regarding its New Drug Application (NDA) for oral paclitaxel plus encequidar for the treatment of metastatic breast cancer.
- The FDA indicated that the review cycle is complete and that the application is not ready for approval in its present form.
- The Agency indicated its concern of safety risk in terms of an increase in neutropenia-related sequelae on the oral paclitaxel arm compared with the IV paclitaxel arm.
- Uncertainty over the results of the primary endpoint of objective response rate at week 19 was also worrisome. The Agency stated that the BICR reconciliation and re-read process may have introduced unmeasured bias and influence on the BICR.
- Athenex was recommended to conduct a new adequate and well-conducted clinical trial in a patients with breast cancer.
- The Agency determined that additional risk mitigation strategies to improve toxicity, which may involve dose optimization/exclusion of patients deemed to be at higher risk of toxicity, are required to support potential approval of the NDA.
- Athenex will host a conference call today at 8 a.m. ET to discuss this regulatory update for oral paclitaxel, as well as Q4 2020 financial results.