Efficacy
The use of CYTOGAM® (Cytomegalovirus Immune Globulin Intravenous [Human]) (CMV-IGIV) in patients undergoing solid organ transplantation (SOT) has been shown in studies to confer additional protection to an antiviral in preventing CMV infection, particularly in those at high risk of CMV infection or disease, compared with controls; it is generally well tolerated.1
CYTOGAM May Demonstrate Enhanced Properties When Compared to Standard IGIVs2
CYTOGAM is a purified immune globulin (that is, a hyperimmune globulin) that contains the immunoglobulin G.2
- IgG is derived from pooled adult human plasma selected for high titers of anti-CMV antibodies3
- In one phase 2 study, CMV IgG antibody titers and neutralizing activity for CYTOGAM were compared with those in other IGIV preparations2
Higher CMV-specific Antibody Titers Were Observed in CYTOGAM vs IGIV Preparations2
CYTOGAM has 5- to 8-fold higher CMV-specific antibody titers vs a standard IGIV.2
CMV-specific IgG antibody concentration. Data are shown as medians for all lots tested (Cytotect CP, n=2; Cytogam, n=3; IGIV 1, n=1; IGIV 2, n=1). Values (PEIU/mL) for individual lots were: Cytotect CP, 111.8, 91.7; Cytogam, 112.9, 85.5, 131.2; IGIV 1, 13.5; IGIV 2, 21.3.
CMV, cytomegalovirus; IgG, immunoglobulin G; IGIV, polyspecific immunoglobulin administered intravenously; PEIU, Paul Ehrlich Institute units.
The Neutralizing Activity of CYTOGAM Was 4-fold Higher Than That of the IGIV Preparations2
Neutralization titer. Data are shown as medians for all lots tested (Cytotect CP, n=2; Cytogam, n=3; IGIV 1, n=1; IGIV 2, n=1). Values (PEIU/mL) for individual lots were: Cytotect CP, 1:256, 1:256; Cytogam, 1:512, 1:256, 1:256; IGIV 1, 1:64; IGIV 2, 1:64.
IGIV, polyspecific immunoglobulin administered intravenously; PEIU, Paul Ehrlich Institute units.
A Clear Correlation Has Been Observed Between the CMV-specific IgG Antibody Concentration in CMV-IGIV and the Viral Neutralization Titer2
Correlation between CMV-specific IgG concentration and neutralization titer
CMV, cytomegalovirus; IgG, immunoglobulin G; PEIU, Paul Ehrlich Institute units.
STUDY DESIGN: The functionality of 2 CMV-IG preparations and 2 IGIV preparations were compared in terms of: (i) CMV-specific immunoglobulin G (IgG) antibody levels determined by enzyme-linked immunoabsorbent assay (ELISA), (ii) avidity index using a CMV IgG avidity enzyme immunoassay, (iii) immunoblot assay against CMV-specific antigens, and (iv) anti-CMV microneutralization assay.2
Both CMV IgG Preparations Demonstrated High Binding Against All Antigenic CMV Glycoproteins Tested2
Immunoblot assay showed consistently high binding of both CMV hyperimmune globulin preparations against all antigenic CMV glycoproteins tested. Recognition of certain antigens (IE1, CM2, and p65) was weaker for the two IVIg products.
Results of immunoblot assay for binding against antigenic CMV glycoproteins
In the study, CYTOGAM was observed to bind more strongly to CMV antigens vs standard IGIVs.
| Product | Antigen | |||||
|---|---|---|---|---|---|---|
| IE1 | p150 | CM2 | p65 | gB1 | gB2 | |
| Cytotect CP | +++ | +++ | +++ | +++ | +++ | +++ |
| CYTOGAM | +++ | +++ | +++ | +++ | +++ | +++ |
| IVIg 1 | ++ | +++ | + | ++ | +++ | +++ |
| IVIg 2 | ++ | +++ | + | ++ | +++ | +++ |
Intensity of binding: + = weak; ++ = well visible; +++ = very strong
References: 1. Barten MJ, Baldanti F, Staus A, Hüber CM, Glynou K, Zuckermann A. Effectiveness of prophylactic human cytomegalovirus hyperimmunoglobulin in preventing cytomegalovirus infection following transplantation: a systematic review and meta-analysis. Life. 2022;12:361. doi:10.3390/life12030361 2. Germer M, Herbener P, Schüttrumpf J. Functional properties of human cytomegalovirus hyperimmunoglobulin and standard immunoglobulin preparations. Ann Transplant. 2016:21:558-564. 3. Pelletier JPR, Faisal Mukhtar F. Passive Monoclonal and Polyclonal Antibody Therapies. In: Immunologic Concepts in Transfusion Medicine. Elsevier Health. 2020;16:251-358.