Initial dose of apatinib in Chinese patients with chemotherapy-refractory advanced or metastatic adenocarcinoma of stomach or gastroesophageal junction in third- or later-line setting: 500 mg or 850 mg?

35 Background: A fine balance between maintaining efficacy and reducing toxicity is necessary for drug therapies in many cancers. This study seeks to review the data from phase IV clinical trial of Ahead-G201 to help elucidate the optimal initial dose of apatinib in advanced gastric cancer. Methods: Pts data from the Ahead-G201 study at cut-off date of Jul 10, 2017 were extracted to explore the correlation of apatinib initial dose (500 mg vs 850 mg) with safety and clinical efficacy. Results: 864 of eligible pts received apatinib at an initial dose of 500 mg, and 58 pts received at 850 mg. Dose interruption occurred in 258 pts (33.1%) at 500 mg and in 27 pts (46.5%) at 850 mg. For safety, the most common adverse events (AEs) were proteinuria, hypertension and leukocyte decrease in both groups. Moreover, the incidence of all AEs and grade 3-4 AEs in pts at 500 mg was significantly lower than pts at 850 mg (Table). For efficacy, pts at 500 mg achieved an objective response rate (ORR) of 10.8% and a disease control rate (DCR) of 70.6%, at best response, which were 10.3% and 55.2% in pts at 850 mg. Pts at 500 mg got a significantly longer median progression-free survival (mPFS) and median overall survival (mOS) than pts at 850 mg (PFS, 4.6 mos vs 2.2 mos; OS, 6.8 mos vs 4.0 mos). Multivariate analysis indicated that apatinib treatment at an initial dose of 500 mg was significantly associated with longer mOS in advanced gastric cancer pts (6.8 mos vs 4.0 mos: hazard ratio, 0.5; 95%CI, 0.3 to 0.8), compared to initial dose of 850 mg. Conclusions: Compared to receiving apatinib at initial dose of 850mg, oral administration of apatinib starting from 500 mg seemed to bring more clinical benefit for patients with advanced gastric cancer, whilst with lower toxicities. Clinical trial information: NCT02426034. [Table: see text]