Final results and subgroup analyses of the phase 3 CAIRO3 study: Maintenance treatment with capecitabine + bevacizumab versus observation after induction treatment with chemotherapy + bevacizumab in metastatic colorectal cancer (mCRC).

Gastrointestinal (Colorectal) Cancer
Session Type and Session Title: 
Oral Abstract Session, Gastrointestinal (Colorectal) Cancer
Abstract Number: 
J Clin Oncol 32:5s, 2014 (suppl; abstr 3504)
Miriam Koopman, Lieke Simkens, Anne Maria May, Linda Mol, Harm van Tinteren, Cornelis J. A. Punt; University Medical Center Utrecht, Utrecht, Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands; Integraal Kankercentrum Nederland, Nijmegen, Netherlands; Department of Statistics, The Netherlands Cancer Institute, Amsterdam, Netherlands

Abstracts that were granted an exception in accordance with ASCO's Conflict of Interest Policy are designated with a caret symbol (^).

Abstract Disclosures


Background: We investigated the efficacy of maintenance treatment with capecitabine (cap) + bev versus observation in mCRC patients (pts) not progressing during induction treatment with cap, oxaliplatin and bev (CAPOX-B). Methods: Previously untreated mCRC pts with stable disease or better after 6 cycles of CAPOX-B were randomized between observation (arm A) or maintenance treatment with cap 625 mg/m2 bid daily continuously + bev 7.5 mg/kg iv q 3 weeks (arm B). Upon first progression (PFS1), pts in both arms were to be treated with CAPOX-B until 2nd progression (PFS2, primary endpoint). Secondary endpoints were overall survival (OS) and time to 2nd progression (TTP2), which was defined as the time to progression on any treatment following PFS1, and quality of life (QoL). Preplanned subset analyses were performed. Results: A total of 558 pts were randomized. Upon PFS1, CAPOX-B was reintroduced in 61% of pts in arm A and 47% in arm B. There was a significant benefit for maintenance treatment for PFS1, TT2PD and PFS2 with a median of 8.5 m vs 11.7 m, respectively (HR 0.67, p < .0001). Multivariable analysis showed a significant interaction for treatment with OS. Subgroup analysis showed a significant interaction for treatment in pts with synchronous metastases with resected primary tumor (n=180): median OS 18.0 m (A) vs 25.0 m (B) (p <0.0001), and for pts with complete/ partial response to induction treatment before randomization (n=366) with median OS of 18.8 m (A) and 24.1 m (B; p < .0001). QoL was maintained during maintenance treatment, and was clinically not inferior compared to QoL in the observation arm. Conclusions: Final CAIRO3 results establish the benefit of maintenance treatment with cap + bev after first-line induction treatment in pts with mCRC. Multivariable analysis shows a significant interaction of treatment with OS. Our finding that the positive effect on survival for maintenance treatment is most pronounced in pts with synchronous disease and resected primary tumor and with PR/CR to induction treatment should be confirmed.