The study compared romiplostim with placebo in the treatment of chemotherapy-induced thrombocytopenia in patients with solid tumors. Eighteen patients received romiplostim, of which 14 (78%) had previously required at least one chemotherapy dose reduction due to thrombocytopenia. After administration of romiplostim, the need for dose reduction decreased in 4 of 22 patients (18%), a statistically significant difference (P=0.0002). Romiplostim once or twice weekly increased platelet counts to ≥100×10^9/L in most patients and allowed chemotherapy to be continued at full dose and on time. The study showed a significant reduction in chemotherapy delays and dose reductions caused by thrombocytopenia. Romiplostim safely increased platelet counts even in patients with pre-existing thrombocytopenic conditions such as immune thrombocytopenia or cirrhosis. Six patients had platelets ≥400×10^9/L, leading to drug dose reduction, with no apparent adverse effects.