Efficacy and safety of weekly paclitaxel with or without ramucirumab as second-line therapy for the treatment of advanced gastric or gastroesophageal junction adenocarcinoma (RAINBOW-Asia): a randomised, multicentre, double-blind, phase 3 trial.

Background: In the global phase 3 RAINBOW study, ramucirumab plus paclitaxel significantly improved overall survival compared with placebo plus paclitaxel in patients with advanced gastric or gastro-oesophageal junction (GEJ) adenocarcinoma. RAINBOW-Asia, a bridging study with similar design to RAINBOW, aimed to evaluate the efficacy and safety of ramucirumab plus paclitaxel for advanced gastric or GEJ adenocarcinoma in Asian, predominantly Chinese, patients.
Methods: RAINBOW-Asia was a randomised, double-blind, placebo-controlled, phase 3 trial done at 32 centres in China, Malaysia, the Philippines, and Thailand. Adult patients (≥18 years) with metastatic or locally advanced, unresectable gastric or GEJ adenocarcinoma who previously received fluoropyrimidine-platinum-based chemotherapy were randomly assigned with a centralised interactive web response system in a 2:1 ratio to receive ramucirumab 8 mg/kg or placebo intravenously on days 1 and 15 plus paclitaxel 80 mg/m ² intravenously on days 1, 8, and 15 of every 28-day cycle. Randomisation was stratified by Eastern Cooperative Oncology Group performance status and presence of peritoneal metastases. The co-primary endpoints were progression-free survival and overall survival. Efficacy analyses were done in the intention-to-treat population, and safety analysis included patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02898077, and has been completed.
Findings: Between March 2, 2017, and June 30, 2020, 440 patients were randomly assigned to receive ramucirumab plus paclitaxel (n=294) or placebo plus paclitaxel (n=146). Median progression-free survival was 4·14 months (95% CI 3·71-4·30) in the ramucirumab plus paclitaxel group compared with 3·15 months (2·83-4·14) in the placebo plus paclitaxel group (hazard ratio [HR] 0·765, 95% CI 0·613-0·955, p=0·0184). Median overall survival was 8·71 months (95% CI 7·98-9·49) in the ramucirumab plus paclitaxel group and 7·92 months (6·31-9·10) in the placebo plus paclitaxel group (HR 0·963, 95% CI 0·771-1·203, p=0·7426). The most common grade 3 or worse treatment-emergent adverse events were decreased neutrophil count (159 [54%] of 293 patients in the ramucirumab plus paclitaxel group vs 56 [39%] of 145 in the placebo plus paclitaxel group), decreased white blood cell count (127 [43%] vs 42 [29%]), anaemia (46 [16%] vs 24 [17%]), hypertension (21 [7%] vs nine [6%]), and febrile neutropenia (18 [6%] vs one [<1%]).
Interpretation: These findings, along with the results from RAINBOW, support the use of ramucirumab plus paclitaxel as second-line therapy in a predominantly Chinese population with advanced gastric or GEJ adenocarcinoma.
Funding: Eli Lilly and Company, USA.
Translation: For the Chinese translation of the abstract see Supplementary Materials section.
Competing Interests: Declaration of interests CZ and WLZ are employees of Eli Lilly and Company. LS has received grants from Beijing Xiantong Biomedical Technology, Qilu Pharmaceutical, ZaiLab Pharmaceutical (Shanghai), Beihai Kangcheng (Beijing) Medical Technology, and Jacobio Pharmaceuticals; consulting fees from Merck Sharp & Dohme, Merck, Mingji Biopharmaceutical, Haichuang Pharmaceutical, Herbour Biomed, and Boehringer Ingelheim; payment for speakers bureaus from Hutchison Whampoa, Hengrui, ZaiLab Pharmaceutical (Shanghai), and CSTONE Pharmaceutical; and has participated as an advisory board member for Rongchang Pharmaceutical, ZaiLab Pharmaceutical (Shanghai), CSTONE Pharmaceutical, and Bristol Myers Squibb. All other authors declared no competing interests.
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