Defactinib hydrochloride (VS-6063 hydrochloride; PF 04554878 hydrochloride) 是一種新型 FAK 抑制劑，抑制 FAK 在 Tyr397 位點磷酸化，這種作用具有時間和劑量依賴性。Defactinib (VS-6063) inhibits FAK phosphorylation at the Tyr397 site in a time- and dose-dependent manner. RPPA data shows that Defactinib reduces levels of AKT and YB-1 in taxane-resistant cell lines. The expression of pFAK (Tyr397) is statistically significantly inhibited by Defactinib in a dose-dependent manner in all cell lines. Defactinib inhibits pFAK (Tyr397) expression within 3 hours, with a gradual return of expression by 48 hours