Athenex, Hanmi’s U.S. partner, presented the topline data showing that Oraxol, an oral anti-cancer drug, met the primary efficacy endpoint with statistically significant improvement over IV paclitaxel in a phase 3 study in metastatic breast cancer.

The company enrolled a total of 402 typical metastatic breast cancer patients in the study -- 265 in the Oraxol group and 137 in the IV paclitaxel group. The primary efficacy endpoint was overall tumor response rate (ORR). Oraxol is an oral dosage form of the widely used intravenous administered tubulin-stabilizing chemotherapeutic agent paclitaxel. The company licensed out the drug to Athenex in 2011.

According to the clinical results analyzed until July 25, the Oraxol showed a statistically significant improvement ORR compared to IV paclitaxel on the primary efficacy endpoint, with an ORR of 36 percent compared to the 24 percent for IV paclitaxel patients

Also, the results showed that the proportion of confirmed responders with the duration of more than 150 days was 2.5 times higher in the Oraxol group than in the IV paclitaxel group, and there was also a strong trend in progression-free survival and overall survival favoring Oraxol over IV paclitaxel.

The study also showed that the Oraxol group had lower incidence and severity of neuropathy, alopecia, arthralgia and myalgia compared to IV paclitaxel.

However, there were more incidents of grade 4 neutropenia and infection, and gastrointestinal side effects in the Oraxol Group.

“We are excited by the positive results in phase 3 pivotal study, demonstrating improved ORR for Oraxol compared to IV paclitaxel across a full spectrum of analyses and lower incidence of neuropathy,” Athenex’s Chief Medical Officer Rudolf Kwan said. “We will be preparing our new drug application submission as soon as possible and are also investigating additional indications for Oraxol as well as combinations with other anti-cancer drugs, including biologics and immuno-oncology drugs.”

With a longer duration of response observed in this trial, the company will look into the potential of this drug candidate in metronomic dosing and maintenance therapy, Kwan added.