Athenex receives Complete Response Letter for oral paclitaxel + encequidar for the treatment of metastatic breast cancer.- Athenex Inc.

Athenex, Inc., announced that the FDA has issued a complete response letter (CRL) for the company’s New Drug Application (NDA) for oral paclitaxel plus encequidar for the treatment of metastatic breast cancer. The FDA issues a CRL to indicate that the review cycle for an application is complete and that the application is not ready for approval in its present form. In the CRL, the FDA indicated its concern of safety risk to patients in terms of an increase in neutropenia-related sequelae on the Oral Paclitaxel arm compared with the IV paclitaxel arm. The FDA also expressed concerns regarding the uncertainty over the results of the primary endpoint of objective response rate (ORR) at week 19 conducted by blinded independent central review (BICR). The Agency stated that the BICR reconciliation and re-read process may have introduced unmeasured bias and influence on the BICR. The agency recommended that Athenex conduct a new adequate and well-conducted clinical trial in a patient population with metastatic breast cancer representative of the population in the U.S. The Agency 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 NDA. Athenex plans to request a meeting with the FDA to discuss the Agency’s response, engage in a dialogue on the design and scope of a clinical trial to address the FDA’s requirements and align on the next steps required to obtain approval.