Privigen is a solution for infusion (drip into a vein). It contains the active substance human normal immunoglobulin.
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Privigen is used in three main groups of patients:
- Patients who are at risk of infection because they do not have sufficient antibodies (proteins naturally found in the blood that help the body to fight infections and other diseases). These can be people who are born with a lack of antibodies (primary immunodeficiency syndrome, PID). It also includes patients whose lack of antibodies is due to a cancer of the blood (myeloma or chronic lymphoid leukaemia) or children born with acquired immune deficiency syndrome (AIDS), who suffer from frequent infections. These types of conditions are called ?immunodeficiency syndromes? and their treatment is called ?replacement therapy?.
- Patients with certain immune disorders. These patients have an abnormal immune system (the body?s defence system) that needs to be adjusted. They include patients with idiopathic thrombocytopenic purpura (ITP) who do not have enough platelets (components in the blood that help it to clot) and who are at high risk of bleeding, and patients with certain diseases (Guillain-Barré syndrome or Kawasaki disease). This type of treatment is called ?immunomodulation? (immune adjustment).
- Patients who have had a bone marrow transplant. The medicine can only be obtained with a prescription.
Privigen is usually given as an intravenous infusion by a doctor or nurse. The dose and frequency of infusions (how often it is given) depend on the disease being treated. In replacement therapy, the dose may need to be adjusted for patients depending on their response. For full details, see the Summary of Product Characteristics (also part of the EPAR).
The active substance in Privigen, human normal immunoglobulin, is a highly purified protein extracted from human plasma (part of the blood). It contains immunoglobulin G (IgG), which is a type of antibody. IgG has been used as a medicine since the 1980s and has a wide range of activity against organisms that can cause infection. Privigen works by restoring abnormally low IgG levels to their normal range in the blood. At higher doses, it can help to adjust an abnormal immune system and modulate the immune response.
As human normal immunoglobulin has been used to treat these diseases for some time, and in accordance with current guidelines, only two small studies were needed to establish the effectiveness and safety of Privigen in patients.
In the first study, Privigen was used as replacement therapy in 80 patients with PID, with the medicine being infused every three or four weeks. The main measure of effectiveness was the number of serious bacterial infections over a year?s treatment.
The second study looked at using Privigen for immunomodulation in 57 patients with ITP. Privigen was given on two consecutive days. The main measure of effectiveness was the highest blood platelet level that was achieved in the week after Privigen was given.
Privigen was not compared to any other treatment in either study.
In the first study, the patients had an average of 0.08 serious infections per year. Since this is below the predefined threshold of one infection per year, this indicates that the medicine is effective as replacement therapy.
In the second study, 46 (81%) of the 57 patients had a platelet count above 50 million platelets per millilitre at least once during the study. This confirmed that Privigen is effective in immunomodulation.
The most common side effect with Privigen (seen in more than 1 patient in 10) is headache. Some side effects are more likely to occur when using a high rate of infusion, in patients with low immunoglobulin levels, or in patients who have not received Privigen before or for a long time. For the full list of all side effects reported with Privigen, see the Package Leaflet.
Privigen should not be used in people who may be allergic to normal human immunoglobulin or any of the other ingredients, or in patients who are allergic to other types of immunoglobulins, especially where they have deficiency (very low levels) of immunoglobulin A (IgA) and they have antibodies against IgA. Privigen must not be used in patients with hyperprolinaemia (a genetic disorder causing high levels of the amino acid proline in the blood).
According to current guidelines, medicines that have been shown to be effective in patients with PID and in patients with ITP can also be approved for use in the treatment of all types of primary immunodeficiency, as well as low antibody levels due to blood cancers and AIDS in children. They can also be approved for the treatment of patients with Guillain-Barré syndrome, patients with Kawasaki disease and patients undergoing a bone marrow transplant, without the need for specific studies in these diseases.
Therefore, the Committee for Medicinal Products for Human Use (CHMP) concluded that Privigen?s benefits are greater than its risks for patients who require IgG for replacement therapy, for immunomodulation or because of bone marrow transplantation. The Committee recommended that Privigen be given marketing authorisation.