ShorTrip Trial: A Prospective, Multicentric Phase II Single-Arm Trial of Short-Course Radiotherapy Followed by Intensified Consolidation Chemotherapy With the Triplet FOLFOXIRI as Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer

Background: In patients with locally advanced rectal cancer (LARC) treated with preoperative (chemo) radiotherapy and surgery, adjuvant chemotherapy is poorly feasible and its benefit is questionable. In the last years, several total neoadjuvant treatment (TNT) strategies, moving the adjuvant chemotherapy to the neoadjuvant setting, have been investigated with the aim of improving compliance to systemic chemotherapy, treating micrometastases earlier and then reducing distant recurrence. Patients and Methods: ShorTrip (NTC05253846) is a prospective, multicentre, singlearm phase II trial where 63 patients with LARC will be treated with short-course radiotherapy followed by intensified consolidation chemotherapy with FOLFOXIRI regimen and surgery. Primar y endpoint is pCR. Among the first 11 patients who started consolidation chemotherapy, a preliminary safety analysis showed a high rate of grade 3 to 4 neutropenia (N = 7, 64%) during the first cycle of FOLFOXIRI. Therefore, the protocol has been emended with the recommendation to omit irinotecan during the first cycle of consolidation chemotherapy. After amendment, in a subsequent safety analysis focused on the first 9 patients treated with FOLFOX as first cycle and then with FOLFOXIRI, grade 3 to 4 neutropenia was reported in only one case during the second cycle.Aim of the study: The aim of this study is to assess the safety and activity of a TNT strategy including SCRT, intensified consolidation treatment with FOLFOXIRI and delayed surgery. After protocol amendment, the treatment seems feasible without safety concern. Results are expected at the end of 2024.