Efficacy and Safety of Apatinib in the Treatment of Chemotherapy-Refractory Metastatic Colorectal Cancer: A Systematic Review

The purpose of this study was to systematically review the current evidence on apatinib and offer a better understanding of its safety and efficacy in metastatic colorectal cancer (mCRC) patients who have not responded to standard chemotherapies. This systematic review was conducted using research from the last 10 years (May 30, 2012, to May 30, 2022) and was obtained from the following databases: PubMed, PubMed Central (PMC), ScienceDirect, and Google Scholar. After removing duplicates, screening titles and abstracts, and applying eligibility criteria and quality appraisal, 11 articles were left for this systematic review (one meta-analysis, eight non-randomized studies, and two traditional reviews). Out of the 11 studies, six were on apatinib monotherapy, while three were on apatinib combination therapy. Apatinib has demonstrated efficacy in the monotherapy and combination therapy trials and has exhibited an acceptable safety profile as the adverse events were predominantly graded 1-2 and could be easily managed. Therefore, apatinib is an encouraging candidate for third-line therapy in chemotherapy-refractory mCRC patients. This conclusion should be confirmed and validated by studies with larger, randomized clinical trials to gain better insight and to directly compare the efficacy and safety of apatinib with all current third-line therapies together so that clinicians can easily assess which treatment modality is superior for chemotherapy-refractory mCRC patients.

Refractory Metastatic Colorectal Cancer: Current Challenges and Future Prospects

Despite advances, patients with metastatic colorectal cancer (mCRC) still have poor long-term survival. Identification of molecular subtypes is important to guide therapy through standard treatment pathways and holds promise for the development of new treatments. Following standard first- and second-line chemotherapy plus targeted agents, many patients retain a reasonable performance status, and thus are seeking further effective treatment to extend life and maintain symptom control. The challenge lies in selecting the most appropriate therapy in the third- and fourth-line settings, from a range of options including the relatively new oral agents TAS-102 and regorafenib, or rechallenge with previous chemotherapy or anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibodies (mAB). Beyond this, therapy consists of trials involving novel agents and new combinations of treatments with theoretical synergy and/or non-overlapping toxicity. There is a great focus on enhancing immunogenicity in mCRC, to reflect the impressive results of immunotherapy drugs in the small cohort with mismatch repair deficient (dMMR) mCRC. Rare molecular subtypes of mCRC are increasingly being identified, including Her2-positive disease, NTRK fusions and others. Clinical trials exploring the efficacy of immunomodulatory and precision agents are plentiful and will hopefully yield clinically meaningful results that can be rapidly translated into routine care.