Effects of apatinib dose interruptions on safety and efficacy in patients with chemotherapy-refractory advanced or metastatic adenocarcinoma of stomach or gastroesophageal junction in third- or later-line setting.

Abstract

142 Background: Apatinib, a small molecule VEGFR TKI, has been approved in the treatment of advanced gastric cancer in China. Due to toxicity, many pts underwent temporary interruptions during treatment. We analyzed the data from a phase IV clinical trial of Ahead-G201 to evaluate the relationship between dose interruption, drug safety and efficacy. Methods: At the cutoff date of Jul 10, 2017, Ahead-G201 study enrolled 1037 pts. The adverse events (AEs) and clinical efficacy were evaluated for pts with no, 1, 2 and ≥3 dose interruptions. Results: 336 of 1037 pts underwent dose interruptions during apatinib treatment: 1 interruption in 183 pts; 2 interruptions in 67 pts; and ≥3 interruptions in 86 pts. The toxicity and efficacy for them were listed in Table. For safety, pts with no interruption had the lowest incidence of all AEs (59.3%) and grade 3-4 AEs (30.0%). Pts with ≥3 interruptions had the highest objective response rate (ORR, 20.3%) and disease control rate (DCR, 82.6%). Moreover, these pts got median progression-free survival (mPFS) of 6.6 mos and median overall survival (mOS) of 9.4 mos, which were the longest among 4 groups. Furthermore, multivariate analysis revealed that ≥3 interruptions of apatinib bring much more efficacy benefit both in mPFS (6.6 vs 3.8 mos: hazard ratio, 0.5, 95%CI, 0.3 to 0.7) and mOS (9.4 vs 6.6 mos: hazard ratio, 0.5, 95%CI, 0.3 to 0.8) for pts, than those with no interruption. Conclusions: Current results indicated that dose interruptions are required to manage toxicity and it is necessary to explore an optimal dosing pattern of apatinib in advanced gastric cancer. Clinical trial information: NCT02426034. [Table: see text]