The efficacy and safety of panitumumab plus irrinotecan-based chemotherapy in the treatment of metastatic colorectal cancer

BACKGROUND Panitumumab, a fully human monoclonal antibody targeting epidermal growth factor receptor, is used in combination with chemotherapy for patients with metastatic colorectal cancer (mCRC). However, the effects of panitumumab in combination with irrinotecan-based chemotherapy remain uncertain. Therefore, we conducted this meta-analysis to assess the efficacy and safety of combination treatment of panitumumab plus chemotherapy in the treatment of mCRC. METHODS By searching electronic databases (PubMed, Embase, and Web of Science), all clinical trials which assessed the effects of panitumumab plus irrinotecan-based chemotherapy in mCRC would be included. Main outcome measures included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and adverse events. Pooled estimates were calculated by a fixed-effects model or random-effects model, according to the heterogeneity among the included studies. RESULTS Eleven trials with a total number of 1338 patients met the inclusion criteria and were included in this meta-analysis. The combination treatment of panitumumab and irrinotecan-based chemotherapy was associated with a median PFS of 5.83 months, OS of 11.15 months, and ORR of 33%. Subgroup analysis showed that, in the first-line and second-line treatment, the combination therapy for PFS was 9.27 and 5.01 months, for OS was 8.87 and 11.68 months, and for ORR was 61% and 26%, respectively. In the wild-type and mutant KRAS populations, the combination therapy for PFS was 5.76 and 5.27 months, for OS was 11.15 and 10.64 months, and for ORR was 37% and 18%, respectively. Moreover, combination therapy also induced an incidence of 56% treatment-related adverse events. CONCLUSION Panitumumab plus irrinotecan-based chemotherapy is effective and well-tolerated in the treatment of patients with mCRC, especially in those with wild-type KRAS tumors.