The phase 3 CAIRO3 study investigated the efficacy of maintenance treatment with capecitabine plus bevacizumab (C + B) versus observation alone in patients with mCRC who were not progressing following induction with chemotherapy plus bevacizumab (CAPOX-B) (Koopman M, et al. ASCO 2014. Abstract 3504). A total of 558 patients with previously untreated mCRC with stable disease or better after 6 cycles of CAPOX-B were randomized between observation alone (Arm A) or maintenance treatment with C + B (Arm B). Upon first progression (PFS1), patients in both arms were retreated with CAPOX-B until second progression (PFS2). There was a significant benefit for maintenance treatment for PFS1 and PFS2, with a median of 8.5 months and 11.7 months, respectively (P <.0001). Median overall survival (OS) for patients with resected primary tumors was 18.0 months (Arm A) versus 25.0 months (Arm B) (P <.0001). This significant difference in OS was also observed in the patients who had a complete or partial response to induction treatment prior to randomization. Quality of life (QOL) in the maintenance treatment and observation arms was similar. The final results from CAIRO3 establish the value of maintenance therapy with C + B in patients with mCRC, both in terms of OS and in maintaining QOL. “Thus, the value proposition of maintenance therapy in these patients is proven by maintaining/prolonging survival.”
