This is the sixth part of our series about the condition based on our patient booklet “Fast Facts for Patients: Thrombotic Thrombocytopenic Purpura”. This article focuses on the treatment for immune thrombotic thrombocytopenic purpura (iTTP), i.e. medications that prevent blood clots (thrombosis) and other supporting medications/treatments, as well as the role of clinical trials.

Immune TTP (iTTP) Treatment: Medications that Prevent Blood Clots (Thrombosis)

Caplacizumab

Caplacizumab is given during an acute iTTP episode. It is an antibody medication that stops von Willebrand factor binding to platelets; it is given to speed up recovery from and reduce the risk of small blood clots (microvascular thrombosis). It is usually given as a daily subcutaneous injection for around 4 weeks during an acute iTTP episode, but sometimes for longer. Most people receiving caplacizumab injections have very few side effects (if any).

 Possible Side Effects

• Increased risk of bleeding, including nosebleeds and heavy periods.

Aspirin and Low-Molecular-Weight Heparin

Aspirin and low-molecular-weight heparin are medications given to thin the blood in acute iTTP episodes. Low-molecular-weight heparin is usually only given in hospital, but you may be given aspirin for several months (sometimes longer). It is important to let your doctor/nurse specialist know if you have any bleeding symptoms.

Immune TTP (iTTP) Treatment: Other Supporting Medications/Treatments

Folic Acid

Folic acid is a vitamin that is needed to make new red blood cells. It is given after an acute iTTP episode to speed up their production.

Omeprazole, Lansoprazole and Ranitidine

These medications protect the stomach against other medications that can irritate it (such as steroids).

Blood Transfusion

Because red blood cells can become damaged and broken down in TTP (hemolysis), it is normal to have a low hemoglobin level (anemia) and require a blood transfusion. The transfusion is given intravenously, either through a cannula or a vascath (both tubes that go into a vein).

Clinical Trials

Clinical trials are very important. They test new treatments for both iTTP and cTTP and compare them with existing treatments. Several important TTP clinical trials have been carried out in recent years, and others are ongoing; they include trials involving caplacizumab for acute iTTP, and recombinant ADAMTS13 for cTTP and acute iTTP. If there are clinical trials that you could join, your doctor will discuss this with you.

Recombinant ADAMTS13

Recombinant ADAMTS13 is an artificial version of the ADAMTS13 enzyme naturally found in human plasma, which has a slightly different structure so antibodies that target ADAMTS13 cannot bind to it. It has the advantage that it is not a blood product (derived from donor blood), so there is no risk of infection.

Recombinant ADAMTS13 has the potential to revolutionize the way TTP is treated. Recombinant ADAMTS13 is currently being given to patients with cTTP and iTTP in clinical trials.

Please check out the other posts of our series here:

• What Is Thrombotic Thrombocytopenic Purpura (TTP)?
• Types and Symptoms of Thrombotic Thrombocytopenic Purpura (TTP)
• How Is Thrombotic Thrombocytopenic Purpura (TTP) Treated?
• Immune Thrombotic Thrombocytopenic Purpura (iTTP) Treatment: Plasma Exchange
• Immune Thrombotic Thrombocytopenic Purpura (iTTP) Treatment: Medications Suppressing the Immune System
• Thrombotic Thrombocytopenic Purpura (TTP): The UK TTP Registry
• Thrombotic Thrombocytopenic Purpura (TTP): 10 Frequently Asked Questions

Information based on Fast Facts for Patients: Thrombotic Thrombocytopenic Purpura (Karger, 2022).