The efficacy and safety of bevacizumab combined with chemotherapy in treatment of metastatic colorectal cancer: Real-World Experience in Thailand

Kanit Ounchokdee 1 , Savitree Maoleekoonpairoj 2 , Kasan Seetalarom 1 , Siriwimon Saichaemchan 1 , Naiyarat Prasongsook

The Thai Cancer, 2020, 31.63.010

Abstract

Backgrond: The comptroller general’s department has approved indication of bevacizumab for metastatic colorectal cancer. However, from February 2018, there was a change in treatment indication to use a combination of bevacizumab and chemotherapy as a second-line colorectal cancer therapy for up to 6 months. Therefore, the aim of this analytical retrospective study was to evaluate the efficacy and safety of bevacizumab in the real-practice database in Thailand.

Method: We reviewed the Oncology Prior Authorization program (OCPA) database between January 2016 and February 2019. A total of 1001 patients with metastatic colorectal cancer was approved to receive bevacizumab combined with chemotherapy. Seven hundred and eighty-nine patients (78.8%) received bevacizumab as a first-line therapy and 212 patients (21.2%) for a second-line treatment. Two hundred and two patients were eligible for overall survival (OS) analysis. The primary endpoint was the overall survival (OS). Secondary endpoint were prognostic factors associated with survival, and safety.

Results: Four hundred patients (40%) had complete of 6 months bevacizumab protocol. The median overall survival was 16.1 months. Median overall survival was longer in the first line treatment than the second line treatment (17.6 months vs 11.35 months, p=0.001). Sixty-eight patients (6.8%) were terminated bevacizumab due to adverse events, and no serious adverse events or death. Multivariate analysis revealed that the completion of 6-month protocol and partial response of disease were significantly associated with overall survival advantage.

Conclusion: From real world experience for additional benefit of bevacizumab in Thailand, OS outcome for first-line setting were inferior to the pivotal studies. However, survival outcome was comparable to previous studies. We may consider adding bevacizumab at first-line setting, and continuation of bevacizumab until progression should be considered.