INNOVA: A phase II randomized study comparing INterval versus NeOadjuVAnt chemotherapy in magnetic resonance imaging-defined high risk rectal cancer.

Abstract

TPS879 Background: Patients with rectal cancers treated with neoadjuvant chemoradiation followed by surgery and adjuvant chemotherapy are not exposed to systemic doses of chemotherapy until very late in the treatment schedule. Preoperative chemotherapy, either in the neoadjuvant or interval setting can lead to early treatment of micrometastasis, improve the tumor response and possibly the overall survival. Phase II studies of neoadjuvant chemotherapy in rectal cancer have shown good response to chemotherapy with no tumor progression and good compliance. A phase II study evaluating the effect of giving chemotherapy in the interval waiting period between chemoradiation and surgery has shown acceptable toxicity and high pathological complete response rates. Methods: This single centre, randomized, open label, phase II trial compares the safety and efficacy of two pre-operative regimens in locally advanced MRI defined high-risk rectal cancers. Based on the Simon optimal two-stage design, 94 patients will be randomised to either Arm A [3 cycles of neoadjuvant chemotherapy (capecitabine and oxaliplatin) followed by chemoradiation (50.4 Gy with capecitabine) and then surgery] or Arm B [neoadjuvant chemoradiation followed by 3 cycles of interval chemotherapy and then surgery]. Patients in both arms receive 3 cycles of adjuvant chemotherapy. The primary end-point is the pathological complete response rate. Secondary end-points include frequency and severity of adverse events, RO resection rates, tumor regression grading and compliance to treatment. The inclusion criteria: age 18 to 70 years; ECOG performance status 0-2; non-metastatic, locally advanced rectal cancer with any one of the following features on high-resolution thin slice MRI: any T3/T4 tumor in the lower rectum, T3c/T3d/T4 tumor in the mid rectum, N2 disease, threatened mesorectal fascia, or extramural vascular invasion. Patients are randomly assigned to one of the two intervention arms in a 1:1 ratio. Prespecified activity goal for the first stage of accrual was met; second stage accrual began in July 2017. Clinical trial information: CTRI/2015/01/005385.