Romiplostim versus Placebo for Chemotherapy-Induced Thrombocytopenia

BACKGROUND: Chemotherapy-induced thrombocytopenia (CIT) is a common complication of chemotherapy that is associated with bleeding, reduced relative dose intensity, and potentially worse outcomes. No widely available therapies are approved for CIT. METHODS: We conducted a phase 3, international, double-blind, randomized, placebo-controlled trial involving patients with persistent CIT (platelet count, ≤85×109 per liter on trial day 1) who were receiving oxaliplatin-based multiagent cytotoxic chemotherapy for gastrointestinal cancers. Patients were randomly assigned in a 2:1 ratio to receive romiplostim or placebo for three chemotherapy cycles. The primary end point was the absence of CIT-induced modifications of the chemotherapy dose (reduction, delay, omission, or discontinuation) in both the second and third chemotherapy cycles. RESULTS: Of the 165 patients who underwent randomization (109 in the romiplostim group and 56 in the placebo group), 75% had colorectal cancer, 13% had gastroesophageal cancer, and 12% had pancreatic cancer; 72% of the patients in the romiplostim group and 61% of those in the placebo group had stage 4 disease. The percentage of patients with no CIT-induced modifications of the chemotherapy dose was 84% (92 of 109 patients) with romiplostim and 36% (20 of 56 patients) with placebo, which corresponded to an odds ratio of 10.16 (95% confidence interval [CI], 4.44 to 23.72; P<0.001) and a risk ratio of 2.77 (95% CI, 1.78 to 4.30; P<0.001). Adverse events of grade 3 or higher occurred in 37% of the patients who received romiplostim and in 22% of those who received placebo, which primarily reflected chemotherapy effects. Adverse events that were considered by the investigator to be related to romiplostim or placebo occurred in 12% of patients who received romiplostim and in 7% who received placebo, with the most frequent being nausea (2% in each group) and headache (2% in the romiplostim group); none were serious or led to death or discontinuation of romiplostim, placebo, or chemotherapy. Thromboembolic events occurred in 2% of patients who received romiplostim and in no patients who received placebo. CONCLUSIONS: In this phase 3, placebo-controlled trial, romiplostim was efficacious in treating CIT. (Funded by Amgen and the Biomedical Advanced Research and Development Authority; RECITE ClinicalTrials.gov number, NCT03362177.).