What happened?

Shares of Athenex (NASDAQ:ATNX) are up by 7.5% as of 12:43 p.m. EDT on Tuesday, after rising by as much as 20.4% earlier today. The market is reacting to Athenex announcing that the FDA has accepted its New Drug Application (NDA) for oral paclitaxel and encequidar for the treatment of metastatic breast cancer. 

So what

Paclitaxel is a chemotherapy drug that is typically administered intravenously. Athenex's oral paclitaxel has, however, shown promise in clinical studies in combination with encequidar. In a pivotal clinical trial, oral paclitaxel with encequidar showed a statistically significant improvement in overall response rate (the percentage of patients whose cancer is reduced or disappears completely after treatment) compared to paclitaxel alone (administered intravenously) in metastatic breast cancer patients.

Microscopic view of a cancer cell.

Image source: Getty Images.

Today, Athenex announced that the FDA has granted priority review to oral paclitaxel and encequidar, and has set a PDUFA target action date of Feb. 28, 2021. Athenex chief medical officer Rudolf Kwan said in a statement: "We are working diligently with the FDA on this Priority Review to bring Oral Paclitaxel to patients with metastatic breast cancer as quickly as possible. Intravenous (IV) Paclitaxel is a foundational chemotherapy in multiple tumor types and we plan to invest in broadening the label and uses for Oral Paclitaxel." The biopharmaceutical company could receive regulatory approval for this treatment sometime next year. 

Now what

Athenex has high hopes for oral paclitaxel. The healthcare company says it believes the drug is "well-positioned to be the preferred chemotherapy in metastatic breast cancer." As this treatment could become an important growth driver for Athenex, it is no wonder investors are bidding up shares of the company today.