FDA Approves Expanded Indication for Thrombate III to Treat Pediatric Patients With hATd

The FDA approved an expanded indication of antithrombin III human concentrate (Thrombate III; Grifols Therapeutics) to include pediatric patients with hereditary antithrombin deficiency (hATd). With this expansion, Thrombate III has become the first and only antithrombin concentrate (ATc) that is approved for both adult and pediatric patients with hATd, according to the manufacturer.¹

hATd is a frequently undiagnosed blood clotting disorder that may affect up to 700,000 people in the US. Patients living with the disease have a higher-than-average risk of developing abnormal blood clots. This expanded indication represents a significant step for patients and families impacted by hATd because the disease has one of the highest thrombotic risks of all inherited thrombophilias, and 85% of patients with hATd will have at least 1 thrombotic episode by 50 years of age.¹

“This label expansion helps close a long-standing gap in the treatment of pediatric patients with hereditary antithrombin deficiency,” George M. Rodgers, III, MD, PhD, professor of medicine in the Division of Hematology and Hematologic Malignancies at the University of Utah School of Medicine, said in a news release. “It gives clinicians added confidence that ATc can be appropriately used in children.”¹

The dose is individualized to achieve an antithrombin level of 80% to 120% of normal human plasma, and the rate of administration is adapted based on individual patient responses, with the full dose given over 10- to 20-minute durations. There are no known contraindications. According to the manufacturers, clinical trials have demonstrated that Thrombate III is an effective choice for patients with hATd and the treatment and prevention of thromboembolism, including before, during, and after surgery and childbirth.^1,2

In a prospective open-label clinical trial, 21 participants were administered Thrombate III for 16 prophylaxis events (n = 13) and 10 for treatment of thrombosis (n = 10), with 2 for both prophylaxis and treatment of thrombosis. Of note, none of the 13 patients with hATd and histories of thromboembolism treated prophylactically on 16 separate occasions with Thrombate III for high thrombotic risk situations (11 surgical procedures and 5 pregnancies and/or deliveries) developed a thrombotic complication. In 3 patients undergoing surgical procedures and 2 of the pregnant patients, heparin was administered. These patients experienced a thrombosis, which was resolved when Thrombate III was added.³

Further, 10 patients with hATd were treated with both Thrombate III and heparin for major thrombotic or thromboembolic complications, including 4 with thrombosis during their first trimester of pregnancy. Among this subpopulation, 9 recovered with no additional thromboses or extension of existing thrombosis. The tenth patient died, but their death was correlated with complications from their original pulmonary embolism with infarction, which occurred prior to treatment with Thrombate III. Of note, most adverse events (AEs) were considered mild or moderate and consisted of dizziness, chest discomfort, nausea, dysgeusia, and pain (cramps). There were no serious AEs reported.³

“Expanding the indication to include pediatric patients provides a new option for children and families facing hATd,” Roland Wandeler, president of Grifols Biopharma, said in the news release.¹

REFERENCES

1. Grifols. Grifols receives expanded indication for THROMBATE III® (antithrombin III [human]) label in U.S., strengthening treatment options for pediatric patients. News release. November 18, 2025. Accessed November 18, 2025. https://www.grifols.com/en/view-news/-/news/grifols-receives-expanded-indication-for-thrombate-iii-antithrombin-iii-human-label-in-us-strengthening-treatment-options-for-pediatric-patients

2. Thrombate III. Thrombate III antithrombin III (human) – About. Accessed November 18, 2025. https://www.thrombate.com/en/thrombate-iii

3. Achieve Balance – Antithrombin (AT) and the coagulation cascade. Updated October 2021. Accessed November 18, 2025. https://www.thrombate.com/documents/6923608/6923682/Fact+Sheet+MOA+%2B+PI.pdf/aeeadde1-d625-5815-5ba6-cdcec994bd15?t=1721124019492#:~:text=3-,DOSAGE%20FORMS%20AND%20STRENGTHS,(WHO)%20antithrombin%20reference%20preparation.