V-IMMUNE: A Novel Immunoglobulin Therapy for Immunodeficiency

Inclusion Criteria: * Patients aged 2 years or older; * Primary immunoglobulin G deficiency, already receiving another intravenous immunoglobulin (IVIG). Primary IgG deficiency may be secondary (non-exhaustive list) to one of the following diagnoses: * Agammaglobulinemia due to absence of B cells * Hypogammaglobulinemia with reduced antibody function - variable common immunodeficiency complex * Quantitative and functional deficiencies of immunoglobulin G * Normal immunoglobulin with reduced capacity for antibody production after immunization (e.g., Wiskott-Aldrich syndrome, IgG subclass deficiency, antipolysaccharide antibody deficiency against Haemophilus or pneumococcus) * Severe combined immunodeficiencies: DiGeorge syndrome presenting with immunoglobulin G deficiency * Isotype-switching defects: hyperimmunoglobulinemia M syndromes * Two trough IgG measurements ≥500 mg/dL within the past 90 days. * Participants with through IgG measurements ≥700 mg/dL within the last 30 days before the first visit Exclusion Criteria: * Acute infection under treatment within 2 weeks prior to screening * Pregnancy * History of hypersensitivity reaction to blood or blood products * Previous anaphylactic reaction to IgG * Intolerance to any component of V-Immune * IgA deficiency, history of reactions to products containing IgA, or history of anti-IgA antibodies * Selective Deficiency of IgA, IgM, IgD, or IgE * Participation in any other study involving an investigational product * Exposure to blood or any blood-derived products in the last 3 months * Known HIV, HCV, or HBV infection * ALT \>3× the upper limit of normal or 3x baseline value * Serum creatinine \>2× the upper limit of normal or 2x baselline value * BUN \>2.5× the upper limit of normal or 2.5x baseline value * History of NYHA class III/IV heart failure * Uncontrolled hypertension with systolic BP \>160 mmHg or diastolic BP \>100 mmHg * History of thrombotic events such as DVT, MI, stroke, or PE within the last 6 months * Neoplasia under treatment * Severe hepatic, renal, or cardiac insufficiency * Child-Pugh class B/C hepatic insufficiency * Alcohol, opioid, or psychotropic drug abuse within the last 12 months * Use of immunosuppressive agents * Long-term use of prednisone \>10 mg/day or equivalent * Protein-losing enteropathies (Crohn's disease, ulcerative colitis, Ménétrier's disease, celiac disease) Observation: If Research participant becomes pregnant during study participation - we will Discontinue any further administration of the IMP; The principal investigator must refer the research participant for follow-up through routine healthcare services; The research participant will continue to be monitored by the study; Obtain informed consent from the pregnant participant to request authorization to follow her pregnancy; If authorized by a specific informed consent form, even after the participant's involvement in the study has ended, the investigator must contact the pregnant participant quarterly to monitor the pregnancy. The results of this follow-up must be entered into the CRF. The frequency will be maintained as long as no abnormalities are identified in the participant, the pregnancy, or the fetus. Female partner of a male research participant becomes pregnant during the study = No action is required regarding the research participant's participation; Obtain informed consent from the research participant's partner to request authorization to monitor her pregnancy. If authorized by a specific informed consent form, the investigator must contact the pregnant woman quarterly to monitor the pregnancy. The results of this follow-up must be entered into the CRF. The frequency will be maintained as long as no abnormalities are identified in the pregnant woman, the pregnancy, or the fetus. Data Confidentiality: The confidentiality of data from all patients will be ensured and preserved. Patient identification will be performed exclusively through the study-assigned identification number, the patient's initials, and date of birth. An exception to this procedure applies to participants included in the pharmacokinetic analyses, who, after providing consent themselves or through their legal representative, will also have their personal identifying data (full name, CPF \[Brazilian individual taxpayer registry number\], date of birth, and sex), as well as information regarding their participation (date of study enrollment), collected and transferred to the ICF laboratory for registration in the SINEB system (Sistema de Informações de Estudos de Equivalência Farmacêutica e Bioequivalência), an ANVISA database used for the registration of participants in studies of this nature. Data obtained from medical records and other documents will be maintained in a confidential manner by the research centers and stored in locations with restricted access limited to the study team. Sensitive data, such as patient contact information collected for scheduling and follow-up purposes, will be accessed exclusively by personnel involved in the conduct of the study. The principal investigator shall allow direct access to participants' records and source documents for the purposes of monitoring, auditing, or inspection by the Sponsor and Regulatory Authorities, if required. With regard to participants included in the pharmacokinetic analyses, the collection of personal identifying data (full name, CPF \[Brazilian individual taxpayer registry number\], date of birth, and sex) and participation-related information (date of study enrollment) is planned for transfer to the ICF laboratory for registration in the SINEB database. This procedure aims to mitigate risks to research participants by ensuring that they are not concurrently enrolled in another study within an interval shorter than six (6) months.