Neoadjuvant capecitabine, oxliplatin, and bevacizumab (CAPOX-B) in intermediate-risk rectal cancer (RC) patients defined by magnetic resonance (MR): GEMCAD 0801 trial.

3586 Background: Retrospective data suggest that RT might not be needed in all patients with stage II/III RC. Modern systemic therapy might have local efficacy similar to chemoradiation (CRT). Methods: A multicenter phase II trial was undertaken to evaluate safety and efficacy of neoadjuvant CAPOX-B in patients with T3 middle third rectal adenocarcinoma. Eligible patients (pts) had measurable disease at the baseline and candidate for R0 total mesorectal escision (TME) with intermediate-risk defined by pelvic MR a) T3 with distal border of tumor > 5 cm from the anal verge and below the sacral promontory. b) tumor ≥2 mm from the mesorectal fascia. Pts received 4 cycles of Cap 2000 mg/m2 (d1-14), Ox 130 mg/m2 (d1) and B 7.5 mg/kg (d1) every 3 weeks (last cycle without B). Pts undergo re-staging with MR. One radiologist reviewed all pre- and post-treatment MR scans independently. Pts without progression proceed to TME 4-6 weeks from the last cycle. If progression, pts were to be referred for pre-op cap/RT followed by TME. 1º Endpoint: Tumor Response (RECIST). Design: Simon 2-stage; 28 pts 1st stage and 46 pts 2nd stage. We report data on the planned analysis of pts included for 1st stage. Results: 28 eligible pts (10F/18M) were enrolled from 7/09-5/11. Tumor response, compliance and toxicity details are shown in table below. Two pN2 pts received postop Cap/RT. Conclusions: Neoadjuvant CAPOX-B is active and safe. Early parameters of efficacy are encouraging and seem similar to those observed with CRT. [Table: see text]