Escalation Part:~Dose escalation of oral ABSK121-NX 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 ABSK121 on Day -7 followed by a 7-day washout (Day -7 dosing day as 1st day of wash out) as a run-in period to access the safety and PK of ABSK121-NX. Then, patients will continuously receive ABSK121-NX once daily (QD) beginning at C1D1.~The dose escalation will start at 3 mg QD followed by dose escalation of a total of 8 potential dose levels. Once RDE is determined, an RDE-confirmation group of up to 24 more patients may be enrolled at the selected dose levels to further evaluate safety and efficacy (up to 12 per dose level/regimen), if approved by the sponsor. In addition, a preliminary food-effect (FE) may be evaluated in Cycle 1 D15 or later in at least 6 patients from the RDE- confirmation part.~After the RDE is determined in the dose escalation part, the dose expansion phase will be conducted.~Expansion Part:~When health authorities outside US require that the safety data in the local population be provided prior to the 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 ABSK121-NX. The inclusion and exclusion criteria for escalation part will apply for these subjects. After similar safety and tolerability of ABSK121-NX 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 ABSK121-NX administered in repeated 28-day cycles in patients with advanced solid tumors to evaluate safety and tolerability. The expansion part will investigate oral ABSK121-NX at the recommended dose for expansion (RDE) to further evaluate safety and tolerability among selected tumor types. Preliminary antitumor activity will also be assessed.