IDH1 Inhibitor AB-218 in Patients With Advanced IDH1 Mutant Cholangiocarcinoma and Other Solid Tumor

This is an open label, single-arm Phase I study to evaluate the safety, tolerability, PK and preliminary efficacy of AB-218, an oral IDH1 inhibitor, for the treatment of adult patients with advanced IDH1 mutant cholangiocarcinoma and other solid tumors who have failed at least one prior therapy in the advanced stage. The study contains a dose escalation part and a dose expansion part. In the dose escalation part, participants are enrolled sequentially into one of 3 dose levels of AB-218 (125 mg BID, 250 mg BID and 500 mg BID) following a 3+3 rule. Intensive PK sampling will be performed during the dose escalation part. Participants will be followed up for DLTs from the date of first study dose to 28 days afterwards. When all participants in the dose escalation part have completed the 28-day DLT observation period, SMC will review the available data including but not limited to safety, tolerability and PK, and then recommend the dose for the study dose expansion part. In the dose expansion part, there are 2 disease cohorts planned: cholangiocarcinoma (CCA) and other IDH1 mutant solid tumors. It is planned to enrol 30 participants in the CCA cohort and another 15 participants in other IDH1 mutant solid tumors, to assess the safety and preliminary efficacy of AB-218. Sparse PK samples will be collected to further evaluate the PK profile in the different target populations. Each participant will undergo screening up to 28 days prior to the start of the treatment period. The treatment period consists of a visit on Day 1 of every 28-day cycle and continues until any of disease progression, unacceptable toxicity, withdrawal of consent or death. An end of treatment (or early discontinuation) visit occurs 30 days (± 7 days) after the last dose of study medication, and a survival follow call every 12 weeks until death, withdrawal of informed consent, loss to follow-up (LTFU) or termination of the study by the sponsor, whichever occurs first.