RhoGAM Rho(D) Immune Globulin (Human) is a sterile solution containing immunoglobulin G (IgG) anti-D (anti-Rh) for use in preventing Rh immunization. It is manufactured from human plasma containing anti-D from Rh-negative donors immunized with Rh-positive red blood cells. A single dose of RhoGAM contains sufficient anti-D (300 μg or 1500 IU) to suppress the immune response to up to 15 mL of Rh-positive red blood cells.7 The anti-D dose is measured by comparison to the RhoGAM in-house reference standard, the potency of which is established relative to the U.S./World Health Organization/European Pharmacopoeia Standard Anti-D Immunoglobulin Rho(D) Immune Globulin (Human).8
Plasma for RhoGAM is typically sourced from a donor center owned and operated by KEDPlasma LLC., US Lic. No. 1876. All donors are carefully screened by history and laboratory testing to reduce the risk of transmitting blood-borne pathogens from infected donors. Each plasma donation is tested and found to be non-reactive for the presence of hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C (HCV) and human immunodeficiency viruses (HIV) 1 and 2. Additionally, plasma is tested by FDA licensed Nucleic Acid Testing (NAT) for hepatitis B virus (HBV), HCV and HIV-1. Each plasma unit must be negative (non-reactive) in all tests. Plasma is tested by in-process NAT procedures for hepatitis A virus (HAV) and parvovirus B19 (B19) in a minipool format. Only plasma that has passed virus screening is used for production. The NAT procedure for B19 detects all three genotypes based upon sequence alignment of known virus isolates. The limit of B19 DNA in the manufacturing pool is set not to exceed 104 IU per mL.
Fractionation of the plasma is performed by a modification of the cold alcohol procedure that has been shown to significantly lower viral titers.3 Following plasma fractionation, a viral clearance filtration step and a viral inactivation step are performed. The viral filtration step removes both enveloped and non‐enveloped viruses as small as approximately 20 nm via a size-exclusion mechanism.
Following viral filtration, quality control tests are performed on the 20 nm filtration membrane to ensure filter integrity. The viral inactivation step (Solvent/Detergent treatment) utilizes Triton X-100 and tri-n-butyl phosphate (TNBP) to inactivate enveloped viruses such as HCV, HIV, HBV and West Nile Virus (WNV).3,9, 10, 11
The donor selection process, the fractionation process, the viral filtration step, the viral inactivation process and other manufacturing process steps increase product safety by reducing the virus load potentially present in the starting material and thus reducing the risk of transmission of enveloped and non-enveloped viruses. Rho(D) Immune Globulin (Human) intended for intramuscular use and prepared by cold alcohol fractionation has not been shown to transmit hepatitis or other infectious diseases.12 There have been no documented cases of infectious disease transmission by RhoGAM.
Laboratory spiking studies, performed in accordance with good laboratory practices 3 have shown that the cumulative viral removal and inactivation capability of the RhoGAM manufacturing process is as follows:
| Virus | HIV-1 | BVDV | PRV | PPV | EMCV |
|---|
| Units = log10 reduction |
HIV Human Immunodeficiency Virus, Relevant virus for HIV-1 and 2 and model virus for Human T-cell Lymphotropic Virus (HTLV) 1 and 2 BVDV Bovine Viral Diarrhea Virus, Model for Hepatitis C Virus and West Nile Virus (WNV) PRV Pseudorabies Virus, Model for large, enveloped DNA viruses such as Herpes Viruses and Hepatitis B Virus PPV Porcine Parvovirus, Model for Parvovirus B19 EMCV Encephalomyocarditis Virus, Model for Hepatitis A Virus N/A Not Applicable |
| Lipid Enveloped | Yes | Yes | Yes | No | No |
| Size (nm) | 80-120 | 40-70 | 120-200 | 18-24 | 25-30 |
| Genome | ss-RNA | ss-RNA | ds-DNA | ss-DNA | ss-RNA |
| Step |
| Methanol precipitation | 5.16 | 4.46 | 4.95 | 4.02 | 4.57 |
| Depth filtration | ≥ 4.95 | 2.53 | 2.34 | 3.83 | Not Significant (<1 Log) |
Viral Grade Filtration (Nanofiltration) | > 3.64 ( > 5.13)
| >2.93 (> 5.31)
| > 6.02 | 4.52 | > 4.61 |
| Solvent/Detergent treatment | ≥ 5.08 | ≥ 4.47 | ≥ 4.05 | N/A | N/A |
| Total Viral Reduction | ≥ 18.83 | ≥ 14.39 | ≥ 17.36 | 12.37 | > 9.18 |
The safety of Rho(D) Immune Globulin (Human) has been further shown in an empirical study of viral marker rates in female blood donors in the United States.13 This study revealed that Rh-negative donors, of whom an estimated 55-60% had received Rho(D) Immune Globulin (Human) for pregnancy-related indications, had prevalence and incidence viral marker rates similar to those of Rh-positive female donors who had not received Rho(D) Immune Globulin (Human).
The final product contains 5 ± 1% IgG, 2.9 mg/mL sodium chloride, 0.01% Polysorbate 80 (non-animal derived) and 15 mg/mL glycine. Small amounts of IgA, typically less than 15 μg per dose, are present.3 The pH range is 6.20 - 7.00 and IgG purity is > 98%. The product contains no added human serum albumin (HSA), no thimerosal or other preservatives and utilizes a latex-free delivery system.
RhoGAM Ultra-Filtered PLUS is manufactured by Kedrion Biopharma Inc., 155 Duryea Road, Melville, NY 11747 USA.