A team from Massachusetts General Hospital used a new drug to save the life of a patient with immune thrombotic thrombocytopenic purpura (iTTP), a rare disorder characterized by uncontrolled clotting in small blood vessels. The drug is a genetically engineered version of the missing enzyme in iTTP, which was able to reverse the disease process in a patient with severe iTTP. iTTP is caused by an autoimmune attack against an enzyme called ADAMTS13, which helps with blood clotting. The current treatment for iTTP involves plasma exchange to remove harmful autoantibodies and provide extra ADAMTS13, but this only restores about half of normal activity. A recombinant form of human ADAMTS13 (rADAMTS13) offers the potential for increased delivery of the enzyme.
Recently approved for congenital thrombotic thrombocytopenic purpura, rADAMTS13 was used in a patient with iTTP who was not responding to standard treatment. Despite concerns about inhibitory autoantibodies against ADAMTS13 rendering the drug ineffective in iTTP, the patient’s disease process was rapidly reversed after receiving rADAMTS13. This success occurred immediately after administration, following failed attempts with daily plasma exchange. The infused rADAMTS13 was able to overcome the inhibitory autoantibodies and reverse the thrombotic effects of iTTP in the patient. This breakthrough led the team to believe that rADAMTS13 could potentially replace the current standard of care for acute iTTP, pending further evaluation in larger clinical trials.
Lead author Pavan K. Bendapudi, MD, believes that rADAMTS13 has the potential to revolutionize the treatment of iTTP and improve outcomes for patients with the condition. He and his colleagues were the first in the United States to use rADAMTS13 to treat iTTP, saving the life of a young mother who was not responding to conventional therapies. This groundbreaking use of the drug shows promise for its efficacy in reversing the disease process in iTTP despite inhibitory autoantibodies. The team’s success with rADAMTS13 in this case has prompted the initiation of a phase 2b randomized clinical trial to further evaluate its effectiveness and potential as a new standard of care for iTTP.
The successful use of rADAMTS13 in treating iTTP marks a significant advancement in the field of rare blood disorders. Being able to reverse the disease process in a patient with severe iTTP who was not responding to standard therapy demonstrates the potential of this novel drug in improving outcomes for those with the condition. By overwhelming inhibitory autoantibodies and reversing the thrombotic effects almost immediately, rADAMTS13 offers hope for a new treatment approach in iTTP. Larger, well-designed trials will be needed to fully evaluate the efficacy and safety of rADAMTS13 in the treatment of iTTP, but this initial success points to a promising future for this innovative therapy.