Escalation Part:~Dose escalation of oral ABSK061 will be guided by the Bayesian optimal interval (BOIN) design based on safety data collected until a maximum tolerated dose (MTD) or maximum administered dose (MAD) has been identified. During the dose escalation part of the study, patients will receive a single dose of ABSK061 on C1D1 only, and then BID dosing for the rest of the days of cycle 1 and in the subsequent cycles. If the actual elimination half-life of ABSK061 is greatly exceeding that predicted, a run-in period with a single-dose and a longer drug-free observation period could be performed in subsequent patients after the Investigator and Sponsor have discussed and agreed.~Expansion Part:~When health authorities outside US require safety data in local population be provided prior to expansion part, a minimum of 3 local subjects will be enrolled and treated at the selected RDE dose level first in that country/region to evaluate the tolerability of ABSK061. The inclusion and exclusion criteria for escalation part will apply for these subjects. After similar safety and tolerability of ABSK061 in patients in the relevant locality have been confirmed by local Investigators and the Sponsor, additional patients will be allowed to enroll in the expansion part.
This is an open-label phase 1 study with expansion. The study will start with a dose escalation of single-agent ABSK061 administered in repeated 28-day cycles in patients with advanced solid tumors to evaluate safety and tolerability. The expansion part will investigate oral ABSK061 at the recommended dose for expansion (RDE) to further evaluate safety and tolerability among selected tumor types. Preliminary antitumor activity will also be assessed.