To determine, for each of two dosing schedules, the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of AZD1152, an Aurora B kinase inhibitor, and to evaluate its safety, biologic activity and pharmacokinetics (PK).

Patients with advanced solid malignancies were treated with escalating doses (100–650 mg) of AZD1152, administered as a 2-h infusion every 7 days (A) or 14 days (B). Adverse events (AEs), PK variables and tumor response were assessed.

Fifty-nine patients were treated; 19 in schedule A and 40 in schedule B. The MTDs were 200 and 450 mg, respectively. Neutropenia (with/without fever) was the most frequent AE and DLT in each schedule. Common Terminology Criteria of Adverse Events version 3.0 grade ≥3 neutropenia and leukopenia occurred in 58% and 11% of patients, respectively, in schedule A and 43% and 20%, respectively, in schedule B. No objective tumor responses were observed at any dose or schedule, although stable disease, as defined by RECIST, was achieved in 15 patients (25%) overall. Systemic exposure to AZD1152-hQPA (active drug) was observed by 1 h into the infusion and exhibited linear PK.

AZD1152 was generally well tolerated with neutropenia being the most frequently reported AE and DLT. Exposure to AZD1152-hQPA, the active drug of AZD1152, was linear.