Maintenance Strategies in mCRC After First-Line Therapy
The optimal maintenance therapy following combination chemotherapy plus bevacizumab (Bev) is still open to controversy. The AIO KRK 0207 trial investigated whether after a 24-week standard first-line induction with a fluoropyridine (FP), oxaliplatin, and Bev, continuation therapy with Bev alone or Bev + FP would be of benefit compared with no maintenance at all (Arnold D, et al. ASCO 2014. Abstract 3503). In this trial, 473 patients with mCRC received 24 weeks of induction therapy with FP/oxaliplatin/Bev, and patients without disease progression were then randomized to receive maintenance therapy with FP + Bev (Arm A), Bev alone (Arm B), or no further treatment (Arm C). At a median follow-up of 27 months, median progression-free survival in Arms A, B, and C were 6.2 months, 4.6 months, and 3.6 months, respectively (P <.0001). Time to failure of strategy (TFS) favored Arm A over Arm C (P = .038), but there was no difference in TFS between Arms A and B. After 200 documented events, there was no significant difference in overall survival (OS) among the 3 arms. While this trial suggests that maintenance therapy with FP + Bev shows significant benefit in TFS over no maintenance, the lack of effect on OS by either active maintenance arm still leaves open to question what the optimal maintenance therapy should be in mCRC following first-line induction therapy.