Antibodies: Proteins made by the body's immune system to attack foreign cells. In ITP, antibodies attack the body's own platelets.1,2

Bone marrow: Tissue inside the bones where blood cells are made.1

Co-insurance: Some insurance coverage requires you to pay a percentage (portion) of the cost of covered medical services, usually 20-30 percent. Your portion of the cost is the co-insurance.3

Co-payment: A flat fee for specified medical services required by some insurers. For example, you pay a $10 co-payment for a doctor visit or a $50 co-payment for a hospital stay. The amount you pay can vary by the type of insurance.3

Durable platelet response: Keeping platelet counts at 50,000 per microliter or above for at least 6 of the last 8 weeks of treatment in 24 week study, without receiving any rescue medication (as defined in Nplate® medical studies).4

Immune thrombocytopenia (throm-bo-sigh-toe-pee-knee-a) (ITP): An autoimmune disease in which the body's immune system attacks and destroys platelets.2

Immunosuppressant: A drug that works by suppressing the immune system.1

Megakaryocyte (meg-ah-carry-oh-sight): Cells found in the bone marrow that produce platelets.1

Overall platelet response: All patients who had either a transient (lasting a short time) platelet response or a durable (long lasting) platelet response (as defined in Nplate® medical studies).4

Placebo: A substance that does not contain any study drug.1

Platelet count: A measure of how many platelets are in the blood, usually expressed in thousands per microliter (e.g., 50,000) or in 109 per liter (e.g., 50 x 109/L). A count of 50 x 109/L is equal to a count of 50,000 per microliter.4

Platelets: Small cell-like bodies that are made by megakaryocytes in the bone marrow and circulate (travel) through the bloodstream. Whenever there is damage to a blood vessel, platelets stick to the area to stop or prevent bleeding.1

Rescue therapies: Non-surgical medical treatment to help prevent life-threatening bleeding (as defined in Nplate® medical studies).4

Splenectomy (splen-ec-ta-me): A surgical procedure that removes the spleen.1

Subcutaneous (sub-cue-tain-ee-us) injection: An injection given under the skin.1

Thrombocytopenia (throm-bo-sigh-toe-pee-knee-a): The general term for having platelet counts lower than 100,000 per microliter. Thrombocytopenia can have a number of different causes. ITP is only one cause of thrombocytopenia.1,5

Thrombopoietin (throm-bo-po-eat-in) (TPO): A protein in the body that signals the megakaryocytes in the bone marrow to make platelets.1

Transient platelet response: Four or more weekly platelet responses in which patients kept platelet counts at 50,000 per microliter or above without durable response from weeks 2-25 (as defined in Nplate® medical studies). Platelet counts within 8 weeks of rescue therapy were not included.4

Weekly platelet response: Platelet counts at 50,000 per microliter or above during a given week (as defined in Nplate® medical studies).4