Oral Paclitaxel and Encequidar Receives FDA Priority Review in Metastatic Breast Cancer
Posted: Tuesday, September 8, 2020
On September 1, the U.S. Food and Drug Administration (FDA) accepted a new drug application and granted Priority Review for oral paclitaxel and encequidar for the treatment of patients with metastatic breast cancer. The FDA’s consideration of the treatment stems from data from a phase III clinical trial studying the efficacy and safety of oral paclitaxel. A total of 402 patients with metastatic breast cancer were randomly assigned to oral paclitaxel monotherapy versus intravenous paclitaxel monotherapy.
The study achieved its primary endpoint, showing a statistically significant improvement of 36% in overall response rate for patients given oral paclitaxel compared with 24% of patients given intravenous paclitaxel (P = .01). In addition, the duration of response for more than 150 days was 2.5 times higher in the oral paclitaxel group than in the intravenous paclitaxel group. Based on the data cutoff on July 25, 2019, there was a strong trend in progression-free survival (P = .077) and overall survival (P = .11) favoring oral paclitaxel over intravenous paclitaxel.
The study reported a lower incidence and severity of neuropathy in patients given oral paclitaxel compared with patients given intravenous paclitaxel. About 57% of patients who received intravenous paclitaxel experienced all grades of neuropathy versus 17% of patients who received oral paclitaxel. Grade 3 neuropathy was observed in 8% of the intravenous paclitaxel group versus 1% in the oral paclitaxel group. The results also showed lower incidences of alopecia, arthralgia, and myalgia with oral paclitaxel. However, patients given oral paclitaxel experienced more incidents of grade 4 neutropenia, infection, and gastrointestinal side effects.
