Study of Immune Globulin Intravenous (Human) GC5107 in Subjects With Primary Humoral Immunodeficiency

This will be a prospective, open-label, single-arm, historically controlled, multicenter
phase 3 study measuring the safety, efficacy and pharmacokinetics and tolerability of GC5107
in subjects with Primary Humoral Immunodeficiency disease (PHID).

Subjects will receive intravenous infusions of the investigational product at the same dose
and interval as used for their previous Immunoglobulin intravenous (IGIV) maintenance
therapy. GC5107 will be administered every 21 or 28 days for a period of 12 months.

Inclusion Criteria:

- Subject with a confirmed clinical diagnosis of a Primary Humoral Immunodeficiency
Disease as defined by IUIS (International Union of Immunological Societies) and
require treatment with IGIV. Documented agammaglobulinemia or hypogammaglobulinemia

- Male or Female, ages 2 to 70 years

- The subject has received 300-900 mg/kg of a licensed IGIV therapy at 21 or 28 day
intervals for at least 3 months prior to this study

- At least 2 documented IgG trough levels of ≥ 500 mg/dL are obtained at two infusion
cycles (21 or 28 days) within 12 months prior to study enrollment

Exclusion Criteria:

- Subject has secondary immunodeficiency

- Subject was newly diagnosed with PHID and has not yet been treated with immunoglobulin

- Subject has been diagnosed with dysgammaglobulinemia or isolated IgG subclass
deficiency or isolated IgA deficiency with known anti-IgA antibodies

- History of severe reaction or hypersensitivity to IGIV or other injectable form of IgG

- Subject has a lifetime history of at least one thrombotic event including deep vein
thrombosis, cerebrovascular accident, pulmonary embolism, transient ischemic attacks,
or myocardial infarction

- Subject has received blood products other than human albumin or human immunoglobulin
within 12 months prior to enrollment