Newly published findings suggest positive results from a late-stage clinical trial on a much-needed treatment option for young people with persistent or chronic primary immune thrombocytopenia (ITP).
ITP is a rare autoimmune disorder that causes a significant reduction in platelets, which are necessary for clotting. Symptoms of ITP include the appearance of petechiae (clusters of red spots where capillaries below the skin have bled), excessive bruising, nose bleeds and prolonged bleeding of the gums after dental procedures. In addition, women living with ITP may experience heavy menstrual bleeding. The disorder can lead to increased fatigue and impact overall quality of life. In the most severe cases, ITP can even become life-threatening.
The global phase 3b clinical trial is evaluating an oral (tablet) therapy known as avatrombopag, which is already approved (under the brand name Doptelet®) by the U.S. Food and Drug Administration for the treatment of adults with chronic immune ITP who were not effectively treated with a previous therapy. The drug is also FDA-approved for the treatment of thrombocytopenia in adult patients with chronic liver disease who are scheduled to undergo an invasive procedure.
The multicenter study, known as AVA-PED-301, was designed to assess the efficacy, safety, tolerability, and pharmacokinetics of avatrombopag for children and adolescents with persistent and chronic primary ITP. The trial included 75 children and adolescents aged 1 to 17 years with ITP, who did not previously respond to other therapies. Participants received either avatrombopag or a placebo over the course of 12 weeks. Ultimately, 54 children received avatrombopag, while 21 were in the placebo group. Within the avatrombopag group, children younger than six years were given a 10-mg oral suspension, and older children were given a 20-mg tablet.
15 (28%) participants in the avatrombopag group met the primary endpoint of durable platelet response by the end of the 12-week period, without the need for a “rescue” medication versus no (0%) patients in the placebo group. A second measure of reaching two or more successive platelet count thresholds associated with being asymptomatic, was met by 81% of patients in the avatrombopag group, compared with none of the patients (0%) in the placebo group.
The most common adverse events reported across treatment groups were petechiae, nosebleeds, and headaches. A few more serious adverse events were reported in five (9%) patients in the avatrombopag group and one (5%) patient in the placebo group. No deaths, thromboembolic events, or severe bleeding events were reported.
These and additional findings were recently published in The Lancet Haematology. In it, investigators gave this interpretation of the results. “Avatrombopag is an effective oral treatment for children and adolescents with ITP for at least six months and has a reassuring safety profile in the paediatric population. Avatrombopag could provide an important treatment option for paediatric ITP.”
The lead author of the study is Rachael Grace, MD, MMSc, a pediatric hematologist and director of hematology clinical research at Dana-Farber/Boston Children Blood and Cancer Disorders Center. (Dr. Rachael Grace was also a NBDF-Takeda Clinical Fellow from 2010-2012, at an early stage of her clinician-researcher career.)
“Many children require ITP treatment to raise their platelet count due to bleeding symptoms, risk of bleeding, and/or the impact of ITP on quality of life,” said Dr. Grace. “Given its efficacy, safety, and treatment attributes, avatrombopag has the potential to address an unmet treatment need for ITP in many children and adolescents.”
Visit the Platelet Disorder Support Association to learn more ITP, additional support, and resources.
Source: Docwirenews, July 18, 2025
