A Study of Investigational Drug CFI-402257 in Patients With Advanced Solid Tumors

CFI-402257 is an oral drug that blocks TTK protein kinase (also known as Monopolar spindle 1 \[Mps1\]) activity. TTK is a protein that is important in regulating cell growth, and cell death, and ensuring proper division. Many tumors are shown to make too much TTK. When there is too much TTK produced, it is believed to contribute to uncontrolled cancer cell growth and division leading to additional mutations in cancer cells. Therefore, it is believed that blocking this protein from working will lead to cancer cell death, stopping tumors from growing or shrinking them. This study has two parts: dose escalation and dose expansion. The dose escalation part tested different dose levels of study drug in groups of patients to find the highest dose of study drug that can be given safely to patients (called maximum tolerated dose or MTD). This part of the study is now complete. The expansion part will further assess the safety, tolerability, and PK of the MTD found in the escalation part of the study in additional group of patients.