[An antigenicity study of calcipotriol (MC903)]

Antigenicity of calcipotriol (MC903), an anti-psoriasic agent, was investigated in mice and guinea-pigs. 1. In mice, MC903 administered alone or with an adjuvant (Alum) did not result in the production of MC903-specific IgE antibody. 2. In guinea-pigs sensitized with MC903 alone or plus an adjuvant (FCA), systemic anaphylaxis was not induced by challenging with MC903. IgG1 antibody in MC903-sensitized guinea-pigs was not detected by the 4-hr PCA test. 3. Ovalbumin induced the production of ovalbumin-specific IgE antibody in mice, and ovalbumin-specific IgG1 antibody in guinea-pigs. Intense systemic anaphylaxis in the ovalbumin-sensitized guinea-pigs was induced by challenging with ovalbumin. 4. Results obtained in the present study suggest that MC903 does not induce the production of IgE antibody in mouse, and IgG1 antibody in guinea-pig, and in MC903-sensitized guinea-pig systemic anaphylaxis is not induced by challenging with MC903.