Hematology
Alexion is currently investigating the use of Soliris® (eculizumab) for the treatment
of other severe, life-threatening blood cell disorders, including Cold Agglutinin
Disease (CAD) and Catastrophic Anti-Phospholipid Syndrome (CAPS).
Cold Agglutinin Disease (CAD)
CAD is a rare blood disorder characterized by activation of the complement cascade
and agglutination, or sticking together, of red blood cells. Patients are typically
first afflicted in their sixties. As blood is cooled during passage through the
limbs, specific antibodies bind to the red blood cells, resulting in activation
of the complement cascade and agglutination of red blood cells. This in turn causes
destruction of red blood cells and symptoms such as fatigue, shortness of breath,
weakness, darkened urine (hemoglobinuria) pallor and jaundice as well as cold-induced
circulatory symptoms ranging from mild discomfort to severe pain in affected limbs
and tissues. In the most severe cases, complications of progressive anemia or complications
of blood transfusions may result in death.
Current therapies, including cold avoidance, corticosteroids, immunosuppressive
drugs, intravenous immunoglobulin G (IgG) and alkylating agents may be ineffective
in controlling red blood cell destruction in many patients with CAD.
In December of 2008, preliminary data on the use of Soliris in a patient with CAD
was presented at the American Society of Hematology annual meeting.29 Further research
is needed to evaluate the potential of Soliris in this patient population.
Catastrophic Antiphospholipid Syndrome (CAPS)
CAPS is a rare and severe form of Antiphospholipid Syndrome (APS)30, an autoimmune
condition characterized by clotting in blood vessels in the presence of antibodies
that target a specific protein called antiphospholipid, or aPL.
In patients with Catastrophic Antiphospholipid Syndrome (CAPS), uncontrollable blood
clots often lead to acute, multiple-organ failure, with potential for amputation
of limbs and death31. CAPS usually strikes adults in the prime of life, and anticoagulant
therapy may be ineffective in many patients with this disease. Among patients experiencing
an initial episode of CAPS, about 25 to 50 percent do not survive32. In animal models,
complement-inhibitor therapy with Soliris reduced blood clotting and tissue damage
related to APS33.