NSABP C-14/Exact Sciences 16-002: CORRECT-MRD II—Second colorectal cancer clinical validation study to predict recurrence using a circulating tumor DNA assay to detect minimal residual disease.
Authors: Salem Mohamed E. , Puhalla Shannon L. , George Thomas J. , Allegra Carmen J. , Arrick Bradley A. , Palomares Melanie R. , Chung Ki Y. , Shipstone Asheesh , McCormack Michael Joseph , Baehner Frederick L. , Wolmark Norman 
Published: August 2024

TPS241

Background:
Detectable circulating tumor DNA (ctDNA) after resection of early-stage solid tumors has been associated with very high risk of recurrence, suggesting ctDNA is evidence of minimal residual disease (MRD). Several studies are ongoing to investigate the role of ctDNA in the optimal management of patients (pts) with colorectal cancer using different assay technologies.
Methods:
This is a prospective, observational, multicenter study in the United States and Canada of 750 pts who have undergone complete surgical resection for stage II or III colorectal cancer, who have FFPE tissue available from the primary resection sufficient for a novel bespoke MRD assay and are willing to provide serial whole blood specimens for ctDNA analysis. Participants are asked to provide study specimens after definitive surgical resection, pre-recurrence follow-up, and clinical recurrence (if applicable). Recently amended eligibility criteria include inclusion of rectal cancer pts who have completed neo-adjuvant therapy and surgical resection, as well as enrollment of all stage II and III pts regardless of microsatellite stability status. The Oncotype Colon Recurrence Score® will be assessed on all pts from their surgical specimen, if criteria are met for this testing. ctDNA will be analyzed with an NGS-based tumor-informed MRD assay that identifies somatic genomic alterations from DNA derived from the patient’s tumor tissue, subtracts germline variants, and detects a selected subset of tumor-specific (bespoke) ctDNA in their blood. All primary tumor specimens will undergo full exome and transcriptome sequencing using the Onco ExTra assay. If there is evidence of disease recurrence, the metastatic tissue will also undergo Onco ExTra testing and results will be shared with participants. The primary objective is to validate the association of post-definitive therapy and pre-recurrence follow-up ctDNA positivity with recurrence-free interval (RFI). Further objectives are to assess the: sensitivity and specificity of ctDNA positivity for subsequent clinical recurrence; contribution of post-surgery baseline, post-adjuvant therapy, and pre-recurrence follow-up ctDNA results on RFI; time from positive ctDNA to clinical recurrence in participants who had a positive ctDNA result; and to compare the Oncotype Colon Recurrence Score estimate of 3-year recurrence risk with the observed 3-year recurrence rate. The primary analysis will use a Cox proportional hazards regression applied to the RFI with ctDNA result (positive or negative) measured after surgery, or end of adjuvant therapy if received, and serially after that as a single, time-dependent covariate. Enrollment has currently surpassed the 50% target. Protocol#: NSABP C-14 / Exact Sciences 16-002 NCT#: 05210283. Support: NSABP Foundation, ExactSciences. Clinical trial information: NCT05210283.