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    A brief summary of a scientific presentation or a publication.

    Acquired hemophilia A

    A bleeding disorder that occurs when the body’s immune system mistakenly attacks its own factor VIII clotting factor. It generally develops in older people between aged 60-80 years.

    Activated prothrombin complex concentrate (aPCC)

    A bypassing agent called FEIBA® that contains active and inactive clotting factors.

    Annualized bleeding rate

    The number of bleeds a person experiences over the course of one year.

    Breakthrough bleed

    Bleeding that occurs when a patient is on prophylactic (preventative) treatment.

    Bypassing agent

    A type of treatment developed for people with inhibitors. These treatments go around (or bypass) the clotting factors that are blocked by the inhibitor to help the body form a clot.

    Clinical trial

    A research study involving human volunteers that plays a key role in evaluating potential new medicines, including their safety and how well they work.

    Clotting proteins

    Proteins found in blood that work together to stop bleeding by forming a blood clot.

    Coagulation cascade

    A complex step-by-step process by which the body forms blood clots. This process involves clotting proteins and other substances.


    The effectiveness of a drug or how well a drug treats the condition for which it is being studied. 

    Episodic treatment

    Using medication to treat bleeding episodes as they occur. Also known as on-demand treatment.

    FVIII Inhibitor

    In hemophilia A, antibodies against infused factor VIII (FVIII or factor 8) clotting proteins. These antibodies make the infused factor VIII products not effective.


    Fibrin is a protein that, when activated, combines with platelets to form clots and scabs.


    How long a drug lasts in the body. Half-life specifically refers to the amount of time it takes for half of a drug dose to be eliminated from the blood stream.

    Hemophilia A

    A genetic bleeding disorder caused by missing or defective clotting protein, factor VIII (FVIII or factor 8). This results in an impaired ability to form a clot and longer bleeding time.

    Immune tolerance induction

    A therapy for people with hemophilia with inhibitors in which the body is trained to recognize factor product without reacting to it.

    Intravenous infusion

    A method to deliver medicine into the body that involves inserting a needle directly into the vein.


    The mid point or middle number in a sorted list of values

    Medication guide

    Medication guides are required by the FDA for certain prescribed medicines when the FDA determines that certain information is necessary to prevent serious side effects, patient decision-making should be informed by information about a known serious side effect with a product, or patient adherence to directions for the use of a product are essential to its effectiveness.

    Patient-reported outcomes

    The patient’s view of the treatment effect on quality of life and ability to function.


    The movement of drug into, through, and out of the body.


    A reporting system to monitor the safety of a drug after it has received approval by health authorities, and includes collecting, assessing, and reporting suspected adverse events or side effects.

    Phase 3 clinical trials

    Phase 3 clinical trials are the third step in testing an experimental treatment after the smaller Phase 1 and Phase 2 clinical trials, which study the safety and find the optimal dosing for a drug. Phase 3 trials are designed to evaluate whether or not a medicine offers a treatment benefit to a population with a specific medical condition. Phase 3 trial completion is the last step before an application may be submitted to the FDA health authorities for evaluation for drug approval.


    Also known as “prophy”. A treatment given on a regular schedule to prevent bleeds.


    A research article appearing in a scientific journal.

    Recombinant product

    A genetically engineered product made without human blood products.


    A genetically engineered version of factor VII made without human blood products. Marketed as NovoSeven among other names.

    Spontaneous Bleed

    A bleeding episode that occurs without an apparent cause.

    Statistically significant

    Two values are considered statistically significant when the difference between them is so large that it cannot be reasonably explained by random chance.

    Subcutaneous injection

    Injecting under the skin, in the fatty layer between the skin and muscle. The medicine is absorbed into the small vessels of the subcutaneous space and goes into the blood where it works.

    Target joint

    A joint that has had recurrent bleeding episodes, or at least 3 bleeds within a 6-month period

    Target joint resolution

    When a joint is no longer considered a target joint. Target joint resolution occurs when there have been ≤ 2 bleeds into the joint within a 12-month period.

    Therapeutic antibody

    Molecules produced by scientists in the laboratory that are designed to recognize and attach to specific proteins to help treat a disease.

    Thrombotic event

    The formation of a blood clot.

    Thrombotic microangiopathy (TMA)

    A condition involving blood clots and injury to small blood vessels that may cause harm to your kidney, brain, and other organs.