Romiplostim versus Placebo for Chemotherapy-Induced Thrombocytopenia

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.

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.

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.

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.).