A Phase I/IIa, Open-label, Multi-center Study to Assess the Safety, Tolerability, Pharmacokinetics and Preliminary Efficacy of the ATR Kinase Inhibitor ART0380 Administered Orally as Monotherapy and in Combination to Patients with Advanced or Metastatic Solid Tumors

ART0380 selectively targets and inhibits ATR activity and blocks the downstream phosphorylation of the serine/threonine protein kinase checkpoint kinase 1 (CHK1). This prevents ATR-mediated signaling, which results in the inhibition of DNA damage checkpoint activation, the disruption of DNA damage repair, and the induction of tumor cell apoptosis.

In this study, the sponsor and investigators want to learn:

• What is the highest dose of the Study Drug that can be given to cancer patients without causing significant side effects?
• How often can the Study Drug be given to cancer patients?
• What are the side effects of the Study Drug when given alone and in combination with irinotecan?
• What effect does the Study Drug have on your tumor when given in combination with irinotecan?
• How is the Study Drug distributed, broken down, and passed out of your body?
• How does the Study Drug affect biomarkers? Biomarkers are substances in your body that can be used to detect a disease or to find out how the cancer is responding to study treatment.