Privigen - human normal immunoglobulin

What is Privigen?

Privigen is a solution for infusion (drip into a vein). Privigen contains the active substance human normal immunoglobulin.

What is Privigen used for?

Privigen is used in three main groups of patients:

patients at risk of infection because they do not have enough antibodies (proteins naturally present in the blood that help the body fight infections and other diseases). These patients have congenital antibody deficiency (primary immunodeficiency syndrome, PID) as well as patients whose antibody deficiency is due to blood cancer (myeloma or chronic lymphoid leukemia) or children with acquired immunodeficiency syndrome (AIDS), subject to frequent infections. These conditions are called immunodeficiency syndromes and the indicated treatment is substitution therapy;
patients with certain immune system disorders. These patients have an anomaly of the immune system (the defense system of the human body) that must be resolved. These may be patients with idiopathic thrombocytopenic purpura (ITP) with an insufficient number of platelets (blood components that promote coagulation) and are at high risk of bleeding and patients with certain diseases (Guillain Barré syndrome, Kawasaki disease ); this type of treatment is called immunomodulation (immune regulation);
patients undergoing bone marrow transplantation.

The medicine can only be obtained with a prescription.

How is Privigen used?

Privigen is given by intravenous infusion, usually by a doctor or nurse. The dose and frequency of infusions (how many times they are administered) depend on the disease being treated. In replacement therapy it may be necessary to change the dose based on the patient's response. For complete information, see the summary of product characteristics included in the EPAR.

How does Privigen work?

The active substance in Privigen, human normal immunoglobulin, is a highly purified protein extracted from human plasma (a component of blood). Basically, it contains immunoglobulin G (IgG), which is a type of antibody. IgG has been used in medicine since the 1980s and has a broad spectrum of activity against infectious organisms. Privigen helps to restore abnormally low IgG levels in the blood to normal levels. At higher doses, it can help regulate an immune system affected by abnormalities and modulate the immune response.

What studies have been carried out on Privigen?

Since human normal immunoglobulin has been used for some time for the treatment of the indicated diseases, only two minor studies were needed to confirm the efficacy and safety of Privigen for patients in accordance with the guidelines in force.

In the first study, Privigen was used as a replacement therapy in 80 patients with PID, with administration at intervals of three or four weeks. The main measure of effectiveness was the number of serious bacterial infections within a year of treatment.

The second study examined the use of Privigen for immunomodulation in 57 subjects with ITP. Privigen was administered for two consecutive days. The main efficacy parameter was the maximum number of platelets obtained during the week following Privigen administration.

In none of the two studies was Privigen compared to other treatments.

What benefit has Privigen shown during the studies?

In the first study, patients had on average 0.08 serious infections in one year. Given that this value is lower than the default threshold of an infection per year, this indicates the effectiveness of the medicine in substitution therapy.

In the second study, 46 (81%) of the 57 patients had a platelet count greater than 50 million platelets per milliliter at least once during the study. This confirmed that Privigen is effective in immunomodulation.

What is the risk associated with Privigen?

The most common side effect of Privigen (seen in more than 1 patient in 10) is headache. Some side effects are most likely to occur if the infusion occurs at high speed, in patients with low immunoglobulin levels or in patients treated with Privigen for the first time or long after the last administration. 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 to any other ingredient or in patients who are allergic to other types of immunoglobulins, particularly if they have immunoglobulin A (IgA) deficiency and have anti-IgA antibodies. Privigen should not be given to patients with hyperprolinemia (a genetic dysfunction that causes high levels of amino acid proline in the blood).

Why was Privigen approved?

Under current guidelines, medicines that have been shown to be effective in patients with PID and in patients with ITP may also be authorized for the treatment of all types of primary immunodeficiency as well as cases of antibody deficiency due to blood cancer and of AIDS in children. They can also be authorized, without the need to carry out specific studies, for the treatment of patients with Guillain Barré syndrome, patients with Kawasaki disease and patients about to undergo bone marrow transplantation.

Therefore the Committee for Medicinal Products for Human Use (CHMP) concluded that Privigen's benefits are greater than its associated risks for patients requiring IgG for replacement therapy, immunomodulation or bone marrow transplantation, and recommended release of the marketing authorization of the product. The Committee recommended that Privigen be given marketing authorization.