A protein found in blood plasma.1

Anaphylactic reaction

A severe allergic reaction which causes the body to become hypersensitive. Because of the potentially life-threatening nature of anaphylactic reactions, emergency medical treatment should be sought if a reaction occurs.2,3

Animal-derived proteins

Proteins isolated from an animal.

Annualized bleed rate (ABR)

The calculated number of bleeds a person experienced over the course of the year.4


Insurance term: A "cap," whether lifetime or annual, is the dollar limit that your insurance company will pay for a specific insurance claim.4

Factor IX

The clotting factor that is deficient in hemophilia B.5

Fc fusion

A recombinant technology where a therapeutic protein, like factor, is fused to the Fc portion of a natural molecule.6,7


Insurance term: A period of time when a person is responsible for 100% of their medical costs. An example includes when a person is between jobs.8,9

HCP (or healthcare provider)

An individual (eg, doctor, nurse, social worker) who provides healthcare services to individuals, families, and/or communities.

Hemophilia B

A genetic condition that results in abnormal and/or ineffective blood clotting due to a deficiency in functional clotting Factor IX.5

Incremental recovery (IR)

The amount of Factor IX that is available in the bloodstream immediately following an infusion.5


An antibody that reduces the activity of a factor replacement therapy.5

Interquartile range (IQR)

Range covering the 25th and 75th percentiles of people in a clinical study; typically used as a more accurate measure of variation as it does not take outliers into account.10


The number in a sequence of numbers for which half of the numbers in the sequence are higher and half are lower. For example, if a sequence of numbers is 2, 3, 5, 10, and 25, the median number is 5.11


A method of purifying clotting factor by using a filtration system to remove very small particles and contaminants.

On demand

Infusion of factor replacement therapy to treat a bleeding episode.5

Pharmacokinetics (PK)

The study of how a drug is absorbed, distributed in tissues, and eliminated from the body.12


The fluid, cell-free part of blood that contains clotting factor, among other things.13


Regular infusions of clotting factor designed to prevent or reduce bleeding.5

Recombinant factor

Factor that is manufactured without the use of blood products.14

Spontaneous bleed

A bleed that occurs without any apparent trigger or cause.14

Terminal half-life

The time it takes for a drug’s activity to decrease by half after the drug has been distributed throughout the body.15

Time to 1%

The amount of time it takes for factor activity levels to decrease to 1% above baseline. It is recommended to keep trough factor activity above 1% to reduce the likelihood of a bleed.16

Trough factor activity

Amount of factor activity in the blood at the end of a dosing interval, just before the next dose is given.5

ALPROLIX® [Coagulation Factor IX (Recombinant), Fc Fusion Protein] is a recombinant DNA derived coagulation Factor IX concentrate indicated in adults and children with hemophilia B for:
  • On-demand treatment and control of bleeding episodes
  • Perioperative management of bleeding
  • Routine prophylaxis to reduce the frequency of bleeding episodes
Limitation of Use
ALPROLIX is not indicated for induction of immune tolerance in patients with hemophilia B.
Important Safety Information

Do not use ALPROLIX if you are allergic to ALPROLIX or any of the other ingredients in ALPROLIX.

Tell your healthcare provider if you have or have had any medical problems, take any medicines, including prescription and non-prescription medicines, supplements, or herbal medicines, have any allergies and all your medical conditions, including if you are pregnant or planning to become pregnant, are breastfeeding, or have been told you have inhibitors (antibodies) to Factor IX.

Allergic reactions may occur with ALPROLIX. Call your healthcare provider or get emergency treatment right away if you have any of the following symptoms: difficulty breathing, chest tightness, swelling of the face, rash, or hives.

Your body can also make antibodies called “inhibitors” against ALPROLIX, which may stop ALPROLIX from working properly.

ALPROLIX may increase the risk of formation of abnormal blood clots in your body, especially if you have risk factors for developing blood clots. Call your healthcare provider or seek emergency care if you have symptoms of a possible abnormal blood clot, which may include: chest pain, difficulty breathing, unexpected swelling of an arm or leg with or without pain or tenderness.

Common side effects of ALPROLIX include headache and abnormal sensation of the mouth. These are not all the possible side effects of ALPROLIX. Talk to your healthcare provider right away about any side effect that bothers you or does not go away, and if bleeding is not controlled using ALPROLIX.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit, or call 1-800-FDA-1088.

Please see full Prescribing Information.