NRG-GI002: A phase II clinical trial platform for sensitization testing using total neoadjuvant therapy (TNT) in rectal cancer.

Abstract

TPS876 Background: Locally-advanced rectal cancer (LARC) improvements have plateaued due to an inability to consistently deliver adjuvant therapy and effective novel therapies. Systematic testing of new chemotherapy and radiation sensitizers are needed to advance treatment outcomes. This randomized phase II modular clinical trial platform utilizes Total Neoadjuvant Therapy (TNT) with parallel experimental arms (EA) in LARC. The EAs are not intended for direct comparison, but rather to test a variety of sensitizers or hypotheses in a consistent and homogenous high-risk patient (pt) population with correlative biomarkers. Success of any EA will be determined by achievement of pathologic endpoints compared to a control arm. Methods: This NCTN multi-arm randomized phase II trial serves as a modular platform to assess novel sensitizers to neoadjuvant chemotherapy and/or chemoradiotherapy (chemoRT) in LARC. Eligibility includes LARC with any ONE of the following criteria: distal location (cT3-4 ≤5cm from the anal verge, any N); bulky (any cT4 or tumor within 3mm of the mesorectal fascia); high risk for metastatic disease (cN2); or not a candidate for sphincter-sparing surgical resection. After randomization, all pts receive neoadjuvant FOLFOX x 4mo → chemoRT (capecitabine with 50.4Gy) → surgical resection 8-12 wks later. The first EA will assess the activity of veliparib with standard chemoRT. A second EA, testing pembrolizumab concurrently with and following chemoRT, is in development. Primary endpoint is a demonstrated improvement in Neoadjuvant Rectal Cancer (NAR) score for the EA vs control representing a 20% relative risk reduction in DFS HR and 3-4% absolute OS improvement. Secondary endpoints include comparisons of OS, DFS, toxicity, pCR, cCR, therapy completion, negative surgical margins, sphincter preservation, sphincter function including quality of life, and exploratory assessments of molecular and radiographic predictors of response and distant failure. Target accrual is 79 evaluable pts per arm with additional EAs added through protocol amendments. NCT02921256. Support: U10 CA-180868, -180822, UG-189867, U24CA196067; AbbVie Clinical trial information: NCT02921256..