Protalex is a biotechnology company developing a new class of drugs with the potential to revolutionize the treatment of autoimmune diseases.
Immune thrombocytopenia (or idiopathic thrombocytopenic purpura ) (ITP) is a rare, serious and often chronic autoimmune disorder characterized by an abnormally low platelet count in the blood (thrombocytopenia). A normal platelet count is between 150,000 and 400,000/microliter of blood. If someone has a platelet count lower than 100,000/microliter of blood with no other reason for low platelets, that person is considered to have ITP1.
Platelets, which are also called thrombocytes, are specialized blood cells needed to prevent bleeding. Low platelet counts leave patients with ITP at risk for bruising and bleeding. The risk of a serious bleeding event increases when platelet counts drop to less than 30,000 platelets per microliter of blood. In extreme cases, death can occur due bleeding into the brain2.
ITP occurs when immune system cells (specialized lymphocytes) produce antibodies that cause the destruction of platelets in the spleen and other organs. As such, ITP historically has been considered a disease of platelet destruction. However, recent data also suggest that platelet counts in the blood may be caused by the inability of the body’s natural processes to produce platelets.
The specific cause of ITP is unknown. In some cases, ITP has appeared following a viral or bacterial infection, immunizations, exposure to a toxin, or in association with another illness such as lupus or the human immunodeficiency virus (HIV). ITP is not contagious.
ITP occurs in children and adults. There are estimated to be about 90,000 adult chronic ITP patients each in Europe and the United States with increasing incidence in older age and equal distribution between men and women except in the mid-adult years (30-60 years), when the disease is more prevalent in women.
ITP is recognized as an orphan disease by U.S. Food and Drug Administration (FDA) and the European Medicines Agency.
Treatments for ITP include therapies that reduce the destruction of platelets (e.g. corticosteroids, intravenous immunoglobulin (IVIG), anti-RhD immunoglobulin (Anti-D), rituximab, cytotoxic drugs, having your spleen removed), or therapies that stimulate the production of new platelets called thrombopoietin receptor agonists (TPO-RAs).
Most patients will initially respond to treatment with traditional therapies like corticosteroids, IVIG and Anti-D. Treatment with newer therapies like the TPO-RAs or rituximab has also produced high response rates in ITP patients who have not had responded adequately to prior therapy.
While the majority of patients with ITP initially respond to treatment with corticosteroids, only 10% to 30% of adult patients enter stable remission once initial therapy is tapered or stopped.
Approximately 80% of patients will respond to either IVIG or Anti-D and the response only lasts for 3-4 weeks
Eltrombopag and romiplostim have shown to be efﬁcacious in splenectomized or nonsplenectomized patients with persistent or chronic thrombocytopenia producing responses in up to 80% of patients. However when these agents are discontinued, thrombocytopenia typically recurs.
Platelet responses are usually noted within 4 to 8 weeks after the 1st infusion but may occur as late as 4 months. A complete or partial remission occurs in 25% to 50% of patients; durable responses (>1 yr) occur in a small percentage of patients4.
The published success rates for splenectomy associated with resolving ITP vary between 50-60 percent.
Mood swings, steroid diabetes, weight gain, fluid retention, osteoporosis, peptic ulcers, hypertension, increased risk of infections
Headaches, renal insufficiency, aseptic memengitis, thrombosis, fever/chills, nausea
Hemolytic anemia, fever/chills, renal failure, intravascular hemolysis
Possible myelofibrosis, venous thrombosis, and rebound thrombocytopenia upon discontinuation. In addition, one agent can cause elevated liver enzymes
Adverse effects include viral reactivation including progressive multifocal leukoencephalopathy (PML), hypogammaglobulinemia, and infusion-related side effects
Splenectomy has potential short- and long-term complications such as compromising the immune system putting patients at risk for serious infections.16 venous thrombosis (blood clots), and surgical complications ITP may recur after the procedure
The actual duration of therapy for a course of treatment varies considerably for the different treatment options.
Since only a small percentage of patients treated will maintain an elevated platelet count after therapy is discontinued continuous or repeated courses of treatment will be necessary
The cost of treatment varies considerably depending on the therapy. Corticosteroid therapy is usually less than $100 a month while the biologic therapies such as IVIG, Anti-D, and rituximab can cost more than $10,000 for a course of treatment and the TPO-RAs may be approximately $5,000/month.
The two most recently approved therapies for ITP, Promacta® (US)/Revolade™ (ROW) and Nplate® generated sales of more than $700M in 2013 so the total market for ITP is assumed to be in excess of $1B.