Primary objective:

To assess the safety and tolerability, describe any dose-limiting toxicity (DLT) for adavosertib

Secondary objective:

To determine the PK profile of adavosertib To describe adavosertib's preliminary anti-tumour activity using the Response Evaluation Criteria in Solid Tumours (RECIST) v1.1

Overall design:

This is a phase I, open-label study to assess the safety, tolerability, PK and anti-tumour activity of adavosertib in Japanese patients with advanced solid tumours. This study consists of 2 cohorts, Cohort1 and Cohort2. At least 3, or up to 6, evaluable Japanese patients with advanced solid tumours will be enrolled in each cohort. The total number of subjects will depend upon the available data in each cohort and the Safety Review Committee (SRC)'s decision.

Study Period:

The study is expected to start in June 2020 and end in April 2021.

Number of Subjects:

6 to 12 evaluable subjects will be enrolled in this study to confirm the tolerability.

Treatments and treatment duration:

Subjects in each part will receive the study treatments as described below:

Cohort 1: Adavosertib 250 mg by mouth (PO) once daily (QD) for 5 days ON and 2 days OFF for week 1 and 2 of a 21 days cycle Cohort 2: Adavosertib 300 mg PO QD for 5 days ON and 2 days OFF for week 1 and 2 of a 21 days cycle Subjects will be allowed to continue adavosertib until disease progression, intolerable toxicity, or discontinuation criteria have been met.