In clinical settings, Abiraterone acetate has been shown to prolong survival in patients with CRPC. It effectively inhibits [³H]-dehydroepiandrosterone (DHEA) depletion and Δ4-androstenedione (AD) accumulation in LNCaP cells, with an IC50 <1 μM. At a dosing regimen of 0.5 mmol/kg/day, serum concentrations of Abiraterone typically range between 0.5 to 1 μM. In xenograft models, tumor growth varies in the control group, with some tumors showing slow growth and others demonstrating more robust expansion^[3].

Abiraterone acetate is an ester prodrug of Abiraterone, a potent anticancer agent that exhibits IC50 values of 15 nM for 17,20-lyase and 2.5 nM for 17α-hydroxylase, both activities of the bifunctional enzyme CYP17. In its active form, Abiraterone specifically inhibits human 17,20-lyase and 17α-hydroxylase with IC50 values of 27 nM and 30 nM, respectively^[1].

Abiraterone significantly inhibits the proliferation of androgen receptor-positive prostate cancer cell lines LNCaP and VCaP at doses ≥5 μM^[2].

Abiraterone also inhibits the activity of recombinant human 3β-hydroxysteroid dehydrogenase types 1 and 2 (3βHSD1 and 3βHSD2), with competitive Ki values of 2.1 μM and 8.8 μM respectively. At a concentration of 10 μM, Abiraterone completely blocks the synthesis of 5α-dione and dihydrotestosterone (DHT) in these cell lines. Furthermore, treatment with Abiraterone significantly inhibits the progression of castration-resistant prostate cancer (CRPC), effectively capping tumor growth over a 4-week treatment period with highly significant results (P<0.00001)^[3].