Local Consolidative Therapy in Colorectal Cancer

This is a Phase II randomized multisite trial to study the effect of a combination of local consolidative therapy with systemic therapy in subjects with oligometastatic colorectal cancer who have progressed on the first line of therapy. The primary objective of this study is progression free survival which is defined as time from randomization until disease progression is documented. Response will be evaluated by scans every 3 months (+/- 7 days). Subjects will continue systemic therapy for 6 months and then at the investigator's discretion, disease progression or unacceptable toxicity. Subjects who are not evaluable for the primary endpoint will be replaced. A total of 105 subjects will be randomized in 2:1 ratio into two cohorts that will receive a combination of LCT along with the systemic therapy or systemic therapy alone. Arm A: LCT + systemic therapy; 70 subjects will be accrued Arm B: Systemic therapy alone; 35 subjects will be accrued Systemic therapy will be second line chemotherapy as per NCCN guidelines with the choice of drugs at the treating physician's discretion. Crossover to LCT will be allowed at progression for subjects randomized to Arm B. The study will be opened at a total of 5 sites with a duration of 26 months of accrual and 10 additional months of follow-up, with a total of 36 months. The study will be conducted in 2 phases with an interim analysis conducted when 29 PFS events have been observed to assess futility/ feasibility of the study. Subjects will have the option of undergoing tumor biopsy and blood sampling before beginning treatment. A correlative study is proposed using the genomic risk group stratification proposed by Pitroda et al.\[9\] Collected blood will be analyzed at the conclusion of the trial, with the expectation of comparing levels of circulating tumor DNA between baseline and 3-month time-points between subjects in Arms A and B. As this technology is rapidly evolving, we are not specifying the technology that will be used and will use the most effective assay at the time of trial completion.