A pharmacokinetically (PK) and pharmacodynamically (PD) driven phase I trial of the pan-AKT inhibitor AZD5363 with expansion cohorts in PIK3CA mutant breast and gynecological cancers.

Background: AZD5363 is a novel potent pan-AKT inhibitor (IC50of AKT1, AKT2 and AKT3 of 3, 7 and 7nM respectively) with preclinical activity across a range of models. Methods: The trial had an adaptive design that allowed changes in schedule based on toxicity, PK, and PD findings. AZD5363 was administered orally (PO) twice a day (BID). Three schedules were explored: continuous dosing (7/7), four days a week, (4/7) and two days a week (2/7). PD biomarkers including pAKT, pGSK3?, and pPRAS40 were measured by IHC in pre- and post-treatment tumor biopsies. Once a RP2D was established, two expansion cohorts of PIK3CA-mutant ER+ve breast (B) and gynecological (G) cancers were explored. Results: 47…