Romiplostim monotherapy increased platelet counts, reduced bleeding in thrombocytopenia, MDS
Patients with thrombocytopenia and low-risk- intermediate-1–risk myelodysplastic syndrome treated with romiplostim monotherapy has higher platelet counts than those treated with placebo, according to study results.
Romiplostim (Nplate, Amgen) monotherapy also was associated with fewer bleeding events and a decreased need for platelet transfusions, results showed.
Aristoteles Giagounidis, MD, of the Clinic for Oncology, Hematology and Palliative Medicine at Marien Hospital in Dusseldorf, Germany, and colleagues randomly assigned 250 patients in a 2:1 ratio to romiplostim or placebo once-weekly for 58 weeks.
During the 26-week treatment period, mean incidence for clinically significant bleeding events per patient was 1.47 in the romiplostim arm and 1.94 in the placebo arm (P=.13).
In the romiplostim arm, researchers observed fewer clinically significant bleeding events among patients with low-risk myelodysplastic syndrome (HR=0.48; 95% CI, 0.29-0.79) and those with a platelet count ≥20 x10⁹/L (HR=0.34; 95% CI, 0.20-0.58).
Overall, patients in the romiplostim arm experienced significantly fewer bleeding events (RR=0.92) and protocol-defined platelet transfusions (RR=0.77). Platelet response rates were higher among patients in the romiplostim arm (OR=15.6).
The study was stopped early due to concerns of excess blasts and acute myeloid leukemia rates with romiplostim (interim HR=2.51). However, at 58 weeks, AML rates were similar between study arms (6% for romiplostim vs. 4.9% for placebo; HR=1.20; 95% CI, 0.38-3.84).
OS rates at 58 weeks also were similar. At that time point, 18% of patients assigned romiplostim and 20.5% of patients assigned placebo had died (HR=0.86; 95% CI, 0.48-1.56).
Disclosure: The researchers report advisory, consultant and speaker roles with, research funding or honorary from, employment relationships with or stock ownership in Amgen, Bristol-Myers Squibb, Celgene, GlaxoSmithKline, Novartis, Onyx, Roche and other pharmaceutical companies.