FDA Approves Adzynma for Treatment of Congenital Thrombotic Thrombocytopenic Purpura

Congenital thrombotic thrombocytopenic purpura (cTTP) can now be treated with Adzynma, the first FDA-approved product that can be used for prophylactic or on demand enzyme replacement therapy (ERT) in both adult and pediatric patients.

cTTP is a rare blood disorder characterized by blood clotting due to a deficiency in the enzyme ADAMTS13, affecting fewer than 1000 people in the United States. Thrombocytopenia, microangiopathic hemolytic anemia, headaches, and abdominal pain are among the effects of cTTP. Mortality of acute TTP events can reach 90% or higher if the disease is left untreated. Treatment has normally included prophylactic plasma-based therapy.

A global study of patients with cTTP was used as the basis for the FDA approval of the genetically engineered protein product, along with a phase 3 trial. The phase 3 trial included patients receiving Adzynma in a 40 IU/kg dose or plasma-based therapy every other week or weekly for the first 6 months before crossing over to the alternative treatment for another 6 months, and then receiving Adzynma for the last 5 months. None of the 37 patients who received Adzynma prophylactic treatment experienced an acute event compared with 1 of the 38 patients who received the plasma-based therapy.

The global study that evaluated prophylactic and on-demand ERT with Adzynma compared with plasma-based therapies included 46 patients who received 6 months of treatment with Adzynma or plasma-based therapies before crossing over to the other treatment for the next 6 months. Efficacy was determined by the number of TTP events and manifestations. The study also evaluated the efficacy of on-demand ERT based on acute events of TTP responding to Adzynma. Adzynma was found to resolve acute and subacute events of TTP in the same manner that plasma-based therapies did.

“Without treatment, cTTP is ultimately fatal. Today’s approval reflects important progress in the development of much-needed treatment options for patients affected by this life-threatening disorder,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in a press release.¹

A purified recombinant form of ADAMTS13 acts as the basis of Adzynma. The medication provides replacement for the low levels of the enzyme in patients with cTTP. This treatment can be given to patients on prophylactic ERT once every other week to reduce risk of disease symptoms and can be used as ERT treatment on demand for patients who are experiencing an acute event once daily.

Headache, diarrhea, migraines, abdominal pain, nausea, upper respiratory tract infection, dizziness, and vomiting were all associated with Adzynma, but no adverse events were observed from intravenous administration of the drug during the clinical studies.

“Adzynma provides patients with a treatment option that replaces their deficient ADAMTS13 enzyme and offers a favorable efficacy and safety profile and reduced administration time and volume compared to current plasma-based therapies. Today marks a significant achievement, providing new possibilities for the cTTP patient community,” Spero R. Cataland, MD, professor of internal medicine at the Wexner Medical Center at The Ohio State University, codirector of the US Thrombotic Microangiopathy Alliance, and Adzynma clinical trial investigator, said in a news release from Takeda, manufacturer of Adzynma.²

References

1. FDA approves first treatment for patients with rare inherited blood clotting disorder. News release. FDA. November 9, 2023. Accessed November 10, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-patients-rare-inherited-blood-clotting-disorder

2. Takeda’s ADZYNMA (ADAMTS13, recombinant-krhn) approved by US FDA as the first and only recombinant ADAMTS13 enzyme replacement therapy for the treatment of congenital thrombotic thrombocytopenic purpura (cTTP). News release. Takeda. November 9, 2023. Accessed November 10, 2023. https://www.takeda.com/en-us/newsroom/news-releases/2023/takeda-adzynma-approved-by-fda-as-the-first-and-only-recombinant-adamts13-enzyme-replacement-therapy-for-the-treatment-of-congenital-thrombotic-thrombocytopenic-purpura