Use of romiplostim for newly diagnosed immune thrombocytopenia in children

Abstract

Immune thrombocytopenia (ITP) is a disease with a heterogeneous clinical manifestation. In the majority of children newly diagnosed ITP is a self-limited benign disorder, while chronic ITP develops rarely. The clinical onset of ITP can occur in very different ways: from nearly invisible skin hemorrhage to severe life-threatening bleeding. Conventional treatments promote a response in most patients, but in a small number of children thrombocytopenia is unresponsive. In this article, we describe our experience of the clinical use of romiplostim in children with severe unresponsive newly diagnosed ITP. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology, and Immunology. The severity of bleeding decreased significantly after the start of romiplostim therapy in all cases. Durable complete (platelets > 100 × 109 /l) response was achieved in five out of six patients 4 to 8 weeks after starting therapy. Three children have remained in lasting remission for 1 to 3 years after the discontinuation of romiplostim. There were no adverse events associated with romiplostim.

Romiplostim in children with newly diagnosed or persistent primary immune thrombocytopenia

“…Several real-world studies and case reports have assessed romiplostim in children with newly diagnosed ITP [29][30][31][32][33][34] (Table 1). The study with the largest cohort of children with newly diagnosed ITP who received romiplostim was a retrospective multicenter chart review, performed at 12 sites in the Pediatric Immune Thrombocytopenia Consortium of North America (ICON) [29].…”

“…Two other retrospective analyses assessing romiplostim have been conducted that included children with newly diagnosed ITP [30,31]. Ramaswamy et al (2014) [30] included a total of 33 children treated with TPO-RAs in the USA; of these, two male patients had newly diagnosed ITP (ITP duration 2 and 3 months, respectively) and received treatment with romiplostim.…”

“…No serious drug-related adverse events occurred with romiplostim in this study. Suntsova et al (2020) [31] included six children (n = 5 male, n = 1 female; ages 3 months to 7 years) with newly diagnosed ITP who received romiplostim. Baseline platelet counts ranged from 1 × 10 9 /l to 7 × 10 9 /l, and all patients had previously received corticosteroids and IVIg; five patients had previously received platelet concentrates and two had received red blood cell suspensions.…”

“…Importantly, there is some evidence that patients with newly diagnosed or persistent ITP develop treatment-free durable platelet responses or lasting remission after treatment with romiplostim [ 31 , 35 , 36 ]. While spontaneous remission is common in children at this stage of disease, it has been speculated that the various biological actions of romiplostim may positively affect remission rates [ 18 , 37 ].…”

“…Use of romiplostim in real-world studies including patients with newly diagnosed or persistent ITP[29][30][31][32][33][34] CR, complete response; ITP, immune thrombocytopenia; PR, partial response Five clinical trials, including two randomized and three long-term open-label studies, have investigated romiplostim in children (< 18 years of age) who had ITP for ≥ 6 months and therefore included patients with persistent or chronic ITP according to the new definition of the three phases of ITP…”