Phase I, Dose Study to Look at the Safety and Pharmacokinetics of AZD8835 in Patients With Advanced Solid Tumours

AZD8835 is a novel small molecule that inhibits cancer progression by blocking PI3 kinase pathway components p110α and p110δ. In this first-time-in-patient study, AZD8835 will initially be administered as a single agent to patients with advanced solid malignancies. Patients will be treated at a starting dose of 20 mg twice daily (BID), administered weekly on Days 1 and 4 and will be escalated to reach a maximum-tolerated dose (MTD) in patients as defined by dose-limiting toxicities (DLTs). A BID intermittent dosing schedule administered weekly on Days 1 and 4 of an oral formulation of AZD8835 will be used, as deemed optimal and effective in non-clinical studies, primarily to determine the safety and tolerability of AZD8835. The pharmacokinetics (PK) of AZD8835 and potential biological activity will also be investigated. In Part A of this study, AZD8835 will be administered as a single agent in a multiple ascending dose escalation phase to investigate the appropriate monotherapy dose level for clinical use. Additional dosing schedules may be studies, including dosing on Days 1 and 2 of each week, rather than Days 1 and 4. Backfilled pharmacodynamic (PDc) cohorts in selected patients with tumours that have documented mutations in the phosphatidylinositol-4,5- bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) gene will allow further preliminary assessment of the biological effect of AZD8835 in these patients. Following the single-agent dose-escalation phase of the study, additional patients with tumours that have documented mutations in the PIK3CA gene will be enrolled to a single-agent dose-expansion phase at the MTD or recommended Phase II dose (RP2D) at the selected dose schedule (as appropriate) to explore further the safety, tolerability, PK, and biological activity at the selected dose (Part B). In addition, a further dose-escalation phase will be initiated following the observation of specific pre-determined criteria in the single-agent dose escalation, in which postmenopausal patients with oestrogen receptor positive (ER+), HER2 negative breast cancer will receive AZD8835 in combination with fulvestrant (Part C). The combination dose-escalation phase will investigate the appropriate combination dose level for clinical use. Following the combination dose-escalation phase of the study, additional postmenopausal patients with ER+ breast cancer and tumours with documented mutations of the PIK3CA gene will be enrolled to a AZD8835 and fulvestrant combination dose-expansion phase at the MTD or RP2D (as appropriate) to explore further the safety, tolerability, PK, and biological activity at the selected dose (Part D).