OBJECTIVE: To probe into the correlation between dose exposure intensity and efficacy and safety of apatinib in the treatment of advanced gastric cancer. METHODS: Totally 44 patients with advanced gastric cancer who received apatinib targeted therapy admitted into the hospital from Jun. 2018 to Nov. 2020 were extracted. Clinical data and medication status of the patients were collected

and the dose exposure intensity was the product of the daily medication dose and the medication time（d）. Kaplan-meier curve

χ~2 test and other statistical methods were used to analyze the clinical efficacy and safety of apatinib in the treatment of gastric cancer at different dose exposure intensity. RESULTS: The mPFS in the high and low dose exposure intensity groups were respectively 5.20 months and 3.90 months

the difference was statistically significant（P=0.006）. The mPFS of the long-term medication group was 5.90 months

longer than 4.00 months of the short-term medication group

with statistically significant differences（P=0.022）. The mOS of the high initial dose group was 7.40 months

shorter than 9.50 months of the low initial dose group

with statistically significant differences（P=0.018）. The mOS of the first-line and second-line apatinib treatment groups was longer than that of the third-line apatinib treatment group

the difference was statistically significant（P=0.001

0.001）. There was no significant difference in mPFS and mOS between the combined immunotherapy group and the non-immunotherapy group（P>0.05）. The mPFS of the combined traditional Chinese medicine group and the non-combined traditional Chinese medicine group were respectively 5.20 and 4.00 months

the combined traditional Chinese medicine group was longer than the non-combined traditional Chinese medicine group

the difference was statistically significant（P=0.041）. The incidence of grade 3 to 4 adverse drug reactions in the high-dose group was higher than that in the low-dose group

and the difference was statistically significant（P<0.05）

mainly including myelosuppression and gastrointestinal adverse drug reactions. CONCLUSIONS: The efficacy of apatinib in the treatment of advanced gastric cancer was significantly positively correlated with dose exposure intensity

high dose exposure intensity could prolong the PFS

and early application of low-dose apatinib（250 mg/d） can improve patients’ tolerance

and adverse drug reactions could be controlled.