TMZ + Olaparib for MGMT Hypermethylated Colorectal Cancer

This is a Phase II, non-randomized, open-label study to evaluate temozolomide in combination with olaparib in patients with MGMT promoter hypermethylated advanced colorectal cancer. Patients will receive temozolomide orally daily on days 1-7 and olaparib twice daily continuously. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatments patients are followed up at 30 days, and for patients that come off treatment for reasons other than disease progression, clinical assessments will continue every 6 weeks for the first year and every 12 weeks after the first year. PRIMARY OBJECTIVES: I. To determine the efficacy of TMZ in combination with olaparib in subjects with MGMT promoter hypermethylated advanced colorectal cancer by the overall response rate. SECONDARY OBJECTIVES: I. To determine the safety of TMZ in combination with olaparib. II. To estimate the progression free survival (PFS). III. To estimate overall survival (OS). EXPLORATORY OBJECTIVES: I. Characterize NGS profiling, patterns of DNA methylation, gene expression, and develop MGMT expression assays. II. Correlate molecular features with Gamma H2AX with response. III. Establish organoids for MGMT promoter hypermethylated colorectal cancer.