Efficacy and Safety of Two Neoadjuvant Strategies With Bevacizumab in MRI-Defined Locally Advanced T3 Resectable Rectal Cancer: Final Results of a Randomized, Noncomparative Phase 2 INOVA Study

Abstract

Background: Recurrence and distant metastases remain a significant issue in locally advanced rectal cancer (LARC). Several multimodal strategies are assessed in clinical trials. Patients and Methods: Patients with mid/low magnetic resonance imaging–defined high-risk LARC were randomized to arm A (12-week bevacizumab + FOLFOX-4 then bevacizumab–5-fluorouracil [5-FU]–radiotherapy [RT] before total mesorectal excision [TME]) or arm B (bevacizumab-5-FU–RT then TME). Long-term efficacy and safety up to 5 years’ follow-up are reported. No comparison between arms was planned. Results: Overall, 91 patients (46 in arm A and 45 in arm B) were included. Main results have been presented previously. During the late follow-up period (> 4 weeks after surgery), 4 patients (8.7%) in arm A and 4 (8.9%) in arm B experienced grade 3/4 adverse events related to bevacizumab; the most frequent were 2 anastomotic fistulas (both in arm A) and abscesses (1 in arm A and 2 in arm B). At 5 years’ follow-up, 9 (19.6%) and 11 (24.4%) patients in arms A and B developed a fistula in the year after surgery, and 2 (4.3%) in arm A at > 1 year after surgery. Most resolved before study end. Five-year disease-free survival was 70% and 64.3% in arms A and B, respectively. Five-year overall survival was 90.5% (95% confidence interval, 76.7, 96.3) in arm A and 72.7% (95% confidence interval, 56.0, 83.9) in arm B. Conclusion: Neoadjuvant bevacizumab + FOLFOX-4 may have the potential to increase survival outcomes when followed by bevacizumab–5-FU–RT and TME in LARC. Bevacizumab–5-FU–RT then TME was associated with a higher-than-projected rate of anastomotic fistulas. Further research of neoadjuvant strategies in LARC is encouraged.