FDA approves avatrombopag for pediatric immune thrombocytopenia, including new sprinkle formulation

FDA approves avatrombopag for pediatric immune thrombocytopenia, including new sprinkle formulation | Image credit: Contemporary Pediatrics

On July 28, 2025, the FDA approved avatrombopag (Doptelet, Sobi North America) for the treatment of thrombocytopenia in pediatric patients aged 1 year and older with persistent or chronic immune thrombocytopenia (ITP) who have had an insufficient response to prior therapy. The approval also includes Doptelet Sprinkle, a new oral granule formulation intended for children aged 1 to less than 6 years.¹

ITP is a rare autoimmune disorder marked by a reduction in platelet counts, leading to an increased risk of bleeding. In children, the incidence is approximately five per 100,000 annually. Although many children experience a short-term form of the disease, up to 25% develop chronic ITP. Symptoms range from mild bruising to severe bleeding and can significantly affect quality of life, including limitations in physical activity due to bleeding risk and fatigue.

“Doptelet represents a significant advancement in the treatment of children and adolescents with persistent or chronic ITP,” said Rachael Grace, MD, MMSc, pediatric hematologist and director of hematology clinical research at Dana-Farber/Boston Children's Cancer and Blood Disorders Center, and lead investigator of the AVA-PED-301 study. “This therapy offers simple, flexible administration because it is oral, available as a tablet and now as a new pediatric sprinkle formulation, and has no food restrictions. The approval of Doptelet for pediatric ITP offers families a new treatment option that can help address challenges in managing ITP in pediatric patients.”

The newly approved Doptelet Sprinkle formulation is indicated for children aged 1 to less than 6 years, while the Doptelet tablet formulation is approved for patients aged 6 years and older.

The FDA’s decision was supported by data from the AVA-PED-301 study, a randomized, phase 3 clinical trial evaluating the efficacy, safety, and pharmacokinetics of avatrombopag in pediatric patients with ITP. ²

According to study results, 27.8% of patients treated with avatrombopag achieved a durable platelet response, defined as a platelet count ≥50,000/μL for at least six of the final eight weeks of the 12-week study, compared with 0% in the placebo group (P = .0077; 95% CI, 15.8–39.7). An alternative endpoint, platelet response defined as 2 consecutive platelet counts ≥50×10⁹/L in the absence of rescue therapy, was achieved by 81.5% of Doptelet-treated patients versus 0% in the placebo group (P < .0001; 95% CI, 71.1–91.8).

At day 8 of treatment, 55.6% of avatrombopag-treated patients had platelet counts ≥50×10⁹/L without rescue therapy (95% CI, 41.4–69.1) compared with none of the placebo-treated patients (95% CI, 0.0–16.1). The treatment was generally well-tolerated. The most commonly reported adverse reactions in ≥10% of pediatric patients included viral infection, nasopharyngitis, cough, pyrexia, and oropharyngeal pain.

“Since its introduction in 2019, Doptelet has been a cornerstone therapy for chronic ITP in adults,” said Duane Barnes, president of Sobi North America. “This approval not only reinforces our commitment to innovation but also allows us to expand the treatment experience for patients and their families by offering Doptelet in two formulations.”

Avatrombopag is a thrombopoietin receptor agonist that is currently indicated for the treatment of thrombocytopenia in adult patients with chronic liver disease scheduled for a procedure, in adult patients with chronic ITP with insufficient response to prior treatment, and in pediatric patients aged 1 year and older with persistent or chronic ITP and insufficient response to previous therapy.

Prescribers should be aware of the risk of thrombotic and thromboembolic events, which have been observed in both adults and pediatric patients receiving thrombopoietin receptor agonists. In patients with chronic liver disease, thromboembolic events occurred in 0.4% (1 of 274) of those receiving avatrombopag. Among adult patients with chronic ITP, thromboembolic events occurred in 7% (9 of 128).

Doptelet should not be used in an attempt to normalize platelet counts in patients with chronic liver disease or ITP, according the the company.

The full prescribing information for Doptelet is available and includes additional safety considerations and administration guidance. Suspected adverse reactions can be reported to Sobi, Inc. at 1-866-773-5274 or to the FDA at 1-800-FDA-1088 or via www.fda.gov/medwatch.

References:

1. Sobi North America. Sobi Announces U.S. Food and Drug Administration Approves Doptelet® (avatrombopag) for the Treatment of Thrombocytopenia in Pediatric Patients One Year and Older with Persistent or Chronic Immune Thrombocytopenia (ITP). BioSpace. July 28, 2025. Accessed July 28, 2025. https://www.biospace.com/press-releases/sobi-announces-u-s-food-and-drug-administration-approves-doptelet-avatrombopag-for-the-treatment-of-thrombocytopenia-in-pediatric-patients-one-year-and-older-with-persistent-or-chronic-immune-thrombocytopenia-itp
2. Grace RF, Leblebisatan G, Aydinok Y, et al. Avatrombopag for the treatment of children and adolescents with immune thrombocytopenia (AVA-PED-301): a multicentre, randomised, double-blind, placebo-controlled, phase 3b study. Lancet Haematol. 2025;12(7):e494-e504. doi:10.1016/S2352-3026(25)00107-3