The Immunogenicity and Safety Profile for KM-248, a Combined Measles, Mumps, and Rubella Vaccine, and Its Noninferiority to the Measles Vaccine in Healthy Japanese Children: a Phase 3 Randomized Multicenter Single-Blind Clinical Trial.

The domestic combined measles-mumps-rubella (MMR) vaccine was withdrawn in Japan in 1993 following an outbreak of aseptic meningitis attributed to the mumps component of the cocktail. KM-248 is an MMR vaccine (M-M-R®II), manufactured by Merck & Co., Inc. (Kenilworth, NJ, USA) and registered and approved in 74 countries, but which has not been approved in Japan. This multicenter, randomized, single-blind study, was designed to evaluate the noninferiority of the KM-248 measles component in terms of immunogenicity when compared to the control measles vaccine already approved in Japan and the seroconversion rates for these three viruses following KM-248 administration. Vaccination with KM-248 in children aged 12-90 months (n = 178) induced robust immune responses to measles, mumps, and rubella viruses. The seroconversion rate for the measles virus by the measles component of KM-248 (n = 172) was shown to be non-inferior to that of the control measles vaccine (n = 85). No serious adverse reactions, such as aseptic meningitis or anaphylaxis, were observed. Fever is one of the most common adverse reactions associated with vaccination and was observed in approximately half of the participants. KM-248 administered to healthy Japanese children aged between 12 and 90 months demonstrated a comparable safety and efficacy profile to the control vaccine.

M-M-R(®)II manufactured using recombinant human albumin (rHA) and M-M-R(®)II manufactured using human serum albumin (HSA) exhibit similar safety and immunogenicity profiles when administered as a 2-dose regimen to healthy children.

Prior to 2006, M-M-R(®)II (measles, mumps, and rubella virus vaccine live) was manufactured using human serum albumin (HSA) and each dose of the vaccine contained a relatively small amount (≤0.3mg) of HSA. Because of specific regulatory requirements and limited suppliers of HSA acceptable for human use, there was a need to replace HSA with recombinant human albumin (rHA) to mitigate any potential risk to the availability of M-M-R(®)II. Two different formulations of M-M-R(®)II manufactured using either rHA or HSA were clinically evaluated for safety and immunogenicity when administered as a 2-dose regimen to healthy children 12-18 months and 3-4 years of age. Adverse events, including those indicative of a possible hypersensitivity reaction, were collected for 42 days after each dose. Antibodies to measles, mumps, and rubella were measured before and approximately 6 weeks after dose 1. Antibodies to rHA were measured before and approximately 6 weeks after dose 1 and dose 2. Antibody seroconversion rates to measles, mumps, and rubella were 97.0%, 99.5%, and 99.7%, respectively, for recipients of M-M-R(®)II with rHA and 97.2%, 97.9%, and 99.6%, respectively, for recipients of M-M-R(®)II with HSA, and geometric mean titers to all 3 vaccine viral antigens were comparable between the 2 vaccination groups. The proportions of subjects who reported adverse events, including those suggestive of hypersensitivity reactions, after each dose of study vaccine were comparable between the 2 vaccination groups. No subject had detectable antibodies to rHA immediately prior to or following receipt of either the first or second dose of study vaccine. Given the comparable immunogenicity and safety profiles of both formulations, rHA is an acceptable replacement for HSA in the manufacture of M-M-R(®)II.