FDA Alert

FDA Approves First Treatment for Adult, Pediatric Patients With Rare Inherited Blood Clotting Disorder

Jessica Ganga

In November 2023, the FDA approved the first genetically engineered protein product to treat adult and pediatric patients with congenital thrombotic thrombocytopenic purpura (cTTP). The product is indicated for preventive or on-demand replacement therapy (ERT).

CTTP is a rare and life-threatening blood clotting disorder that, if left untreated, is “ultimately fatal,” according to Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research.

“Today’s approval reflects important progress in the development of much-needed treatment options for patients affected by this life-threatening disorder,” continued Dr Marks.

The protein product is a purified recombinant form of the ADAMTS13 enzyme. The product works by providing a replacement enzyme for the low levels of the deficient enzyme in patients with cTTP.

The approval follows a global study that evaluated both the preventive and on-demand ERT using the protein product and compared it to plasma-based therapies in patients with cTTP. Overall, in both trials testing the efficacy of the product, cTTP was found to be effective with thrombotic thrombocytopenic purpura (TPP) events either resolving after treatment (after on demand ERT), or demonstrated based on the incidence of TPP events (after preventive ERT).

Additionally, common side effects were reported and included headache, diarrhea, migraine, abdominal pain, nausea, upper respiratory tract infection, dizziness, and vomiting. No adverse events, such as allergic reactions, were observed.


FDA approves first treatment for patients with rare inherited blood clotting disorder. News release. US Food and Drug Administration; November 9, 2023. Accessed February 7, 2023.