What is the MOA for Fabhalta (iptacopan)?

The mechanism of action for Fabhalta (iptacopan) involves the complement system (a group of proteins that help your immune system fight infections). Fabhalta is a complement factor B inhibitor. It works to treat paroxysmal nocturnal hemoglobinuria (PNH) by stopping red blood cells from getting destroyed. This reduces anemia and the need for blood transfusions.

By attaching to factor B, Fabhalta blocks activation of a protein called C3 in the complement system. Normally, C3 is changed into C3b. C3b has two main actions in PNH:

1. C3b tags red blood cells for destruction by phagocytes (an immune cell that ingests and kills other cells). This is known as extravascular hemolysis.
2. C3b activates other proteins that destroy red blood cells in people with PNH. Specifically, it promotes the formation of C5 convertase, which changes C5 into C5b. C5b works with other proteins (C6, C7, C8, and C9) to form a membrane attack complex (MAC). MAC is essentially a hole in the membrane of the red blood cell that causes it to die. This is known as intravascular hemolysis.

Normally, these processes are controlled by proteins called CD55 and CD59. These proteins protect red blood cells from being broken down by the immune system. People with PNH do not have enough of these proteins, causing destruction of red blood cells.

• CD55 helps lower the amount of C3 convertase, which limits the formation of C3b and MAC.
• CD59 attaches to C8 and C9, preventing the formation of MAC.

This is not all the information you need to know about Fabhalta (iptacopan) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.