Understanding PK

PK + You
The Role of PK in Individualizing Your Hemophilia A Treatment

What is Pharmacokinetics (PK)?


Pharmacokinetics is the study of the bodily absorption, distribution, metabolism, and elimination of drugs.

Absorption: How drugs are taken into your body.
Distribution: How drugs move around in your body.
Metabolism: How drugs are broken down in your body.
Elimination: How drugs are eliminated from your body.

Why is PK Testing Important?

PK testing allows your doctor to understand your unique PK profile and create a treatment plan that matches your needs. Talk to your physician about obtaining your PK profile.

How Does PK Testing Help with Your Treatment?

The aim of hemophilia A treatment is to continuously maintain factor VIII at high enough levels with regular infusions to reduce the frequency of bleeding episodes. This is known as prophylaxis, which is the standard of care for treatment of hemophilia A in the United States.

The amount of factor VIII (the drug dose) and the frequency at which it must be given to prevent spontaneous bleeds varies from person to person. PK testing allows doctors to better understand how factor VIII levels behave in your body, so they can better individualize and fine tune your treatment by defining the right dose and infusion frequency for you.

Image representing a boy swimming.

Meet Sam

Sam, a teenage boy, has been selected for his school swimming team but is worried about his risk of bleeds if he trains more regularly.

PK testing could help to adjust his infusion schedule so that his levels of factor VIII are high enough on the days when he wants to train.*

*These are fictional scenarios for illustration only. Treatment decisions should be made by a physician on an individual basis.

What is PK Testing?

PK testing involves working with your physician to measure factor VIII levels in blood samples taken from you over a period of time. With PK testing, your doctor defines your PK profile.

Like a fingerprint, a PK profile is unique for every person with hemophilia A – there is nobody else quite like you! This unique PK profile can be used to make sure that the drug is given in the right amount (the drug dose) and at the right frequency.

Image representing a boy hiking.

Meet Marco

Marco is a 35-year-old man who loves the outdoors and hiking. Together with his doctor, they have been having difficulty finding the right infusion schedule to prevent bleeds.

PK testing could help him find the right infusion frequency to match his needs.*

*These are fictional scenarios for illustration only. Treatment decisions should be made by a physician on an individual basis.

How Do You Get Your PK Profile?

Obtaining Your PK Profile:

What Does Your PK Profile Mean?

Just like your personal profile with your name, address, date and place of birth, your PK profile is defined by a set of characteristics, unique to you.

Let's break them down:

Area Under the Curve (AUC): The total amount of factor that is absorbed and distributed in your bloodstream over a period of time. It is used by your doctor to define the right dose for you.
Half-Life: The amount of time it takes for factor levels to get reduced by half (50%) of what they originally were right after your infusion. It helps your doctor understand how long factor remains active in your body.
Clearance: The speed at which factor is eliminated from your body. The higher the clearance, the faster your body breaks down and eliminates factor. Clearance helps your doctor define the right frequency of infusion for you.
Trough Level: The minimum factor level that your doctor sets individually with you based on your personal needs. The trough level indicates to your doctor when you should take another infusion.

Your PK Profile Helps You Choose the Right Factor VIII Product for You.

Think of your factor VIII product as your car, and the PK profile (area under the curve, half-life, clearance,
and trough level) as the fuel for your car.

Area Under the Curve (AUC): The amount of gas that is used by the car over time after you fill up your tank.
Half-Life: How many miles it takes to go from a full tank to a half tank.
Clearance: How quickly the car uses gas.
Trough Level: The minimum level of gas needed before your low fuel light appears.

Ideally, you would want more gas available for your drive (higher AUC), you would want it to take longer for the gas in your tank to go from a full tank to a half talk (longer half-life), and you would want your car to burn through gas slower (slower clearance). You also want to make sure you have at least a minimum amount of gas in your tank to avoid running out of gas (right trough level).

Talk to your physician about obtaining your PK profile.