Protocol for a Systematic Review: Camrelizumab plus Apatinib in Solid Tumors

Background: Solid tumors represent a significant global health burden, with limited treatment options for advanced or metastatic stages. The combination of camrelizumab, a programmed cell death protein-1 (PD-1) inhibitor, and apatinib, a vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor, has shown promise in preclinical and early-phase clinical studies. However, the efficacy and safety of this combination therapy remain unclear. This systematic review aims to synthesize the available evidence on the use of camrelizumab plus apatinib in solid tumors to inform clinical practice and guide future research. Methods: A comprehensive search of electronic databases, including PubMed, Scopus, Web of Science, and ClinicalTrials.gov, will be conducted from January 2018 to the present. Randomized controlled trials, non-randomized controlled trials, cohort studies, and single-arm trials evaluating camrelizumab plus apatinib in patients with advanced or metastatic solid tumors will be included. The primary outcomes will include the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The secondary outcomes will focus on the incidence and severity of adverse events (AEs). Two reviewers will independently screen studies, extract data, and assess the risk of bias using standardized tools. Data will be synthesized narratively and, if appropriate, through meta-analysis. Discussion: This systematic review will provide a comprehensive evaluation of the efficacy and safety of camrelizumab plus apatinib in solid tumors. The findings will inform clinical decision-making, highlight gaps in the current evidence, and guide the design of future studies. By synthesizing the available data, this review aims to contribute to the development of more effective treatment strategies for patients with advanced or metastatic solid tumors.