Efficacy, Safety and Pharmacokinetics of Gammaplex in Primary Immunodeficiency Diseases.

Inclusion Criteria

• 1. The subject is 3 years of age or older, of either sex, belonging to any ethnic group, and above a minimum weight of 27.5 kg. This weight is based on the amount of blood required for testing. If subject is participating in the PK segment, the minimum weight required is 37 kg.
• The subject has a primary immunodeficiency disease, which has as a significant component of hypogammaglobulinemia and/or antibody deficiency (e.g. (exempli gratia / for example), common variable immunodeficiency, X-linked and autosomal forms of agammaglobulinemia, hyper-immunoglobulin M (hyper-IgM) syndrome, Wiskott-Aldrich Syndrome). Isolated deficiency of a single IgG subclass, or of specific antibodies without hypogammaglobulinemia per se, does not qualify for inclusion.
• The subject has been receiving licensed or investigational (Phase III or IIIb) immunoglobulin intravenous (IGIV) replacement therapy at a dose that has not changed by + 50% of the mean dose for at least 3 months before study entry and is between 300 and 800 mg/kg/infusion. The infusion interval must be between 21 and 28 days inclusive. The subject must have maintained a trough level at least 300 mg/dL (milligram per decilitre) above baseline serum IgG levels (defined as before initiation of any gamma globulin treatment for that subject). The trough level must be 600 mg/dL.
• Trough levels of IgG and dose of IGIV, treatment intervals, and the trade name of the IGIV treatments used for the last 2 consecutive routine (licensed or investigational product) must be documented for each subject before the first infusion in this study can be administered.
• If a subject is a female of child-bearing potential, she must have a negative result on an Human Chorionic Gonadotrophin (HCG)-based pregnancy test.
• If a subject is a female who is or becomes sexually active, she must practice contraception by using a method of proven reliability for the duration of the study.
• The subject is willing to comply with all aspects of the protocol, including blood sampling, for the duration of the study.
• The subject has signed an informed consent form (if at least 18 years old) or the subject's parent or legal guardian has signed the informed consent form. If appropriate, the subject has signed a child assent form (See Section 12.3).

Exclusion Criteria

• Subjects will be excluded if any of the following exclusion criteria are met:
• The subject has a history of any severe anaphylactic reaction to blood or any blood-derived product.
• The subject is known to be intolerant to any component of GAMMAPLEX, such as sorbitol (i.e.(id est / that is) , intolerance to fructose).
• The subject has selective immunoglobulin A (IgA) deficiency, history of reaction to products containing IgA, or has a history of antibodies to IgA.
• Subjects who have completed the study and subjects who have withdrawn cannot participate in the study for a second time.
• The subject is currently receiving, or has received, any investigational agent, other than an immune serum globulin (ISG) preparation that is being evaluated in a Phase III or IIIb study, within the prior 3 months.
• The subject has been exposed to blood or any blood product or derivative within the last 6 months, other than a commercially available IGIV or other forms of commercially available and licensed ISG or an ISG product that is in Phase III or IIIb studies.
• The subject is pregnant or is nursing.
• The subject is positive for any of the following at screening:
• Serological test for Human immunodeficiency virus (HIV) 1&2, Hepatitis C virus (HCV), or Hepatitis B surface antigen (HBsAg)
• Nucleic Acid test (NAT) for HCV
• NAT for HIV
• The subject, at screening, has levels greater than 2.5 times the upper limit of normal as defined at the central laboratory of any of the following:
• Alanine transaminase (ALT)
• Aspartate transaminase (AST)
• The subject has a severe renal impairment (defined as serum creat