Changes in the immunological parameters after a single dose of forphenicinol, a new small molecular immunomodifier.

Forphenicinol [L-2-(3-hydroxy-4-hydroxymethyl-phenyl) glycine, M.W. 197.19] is a derivative of forphenicine, an inhibitor of alkaline phosphatase discovered by Umezawa. In order to find an optimal dose, a single dose of the drug ranging from 10 to 600 mg per body was orally administered to a total of 55 patients (36 cancer, 13 tuberculosis, and 6 others). The possible changes in the percentages of the peripheral T and B lymphocytes, natural killer (NK) activity, and the proliferative response to phytohemaglutinin (PHA) were studied as immunological parameters. A significant effect of forphenicinol was demonstrated in restoring the normal proportion of T and B cells, especially in those who had 'low'-T and/or 'high'-B before administration of the drug. No difference was found between cancer and tuberculosis. The mean percentage of T cells increased from the low initial level of 68.0 to 75.6 in cancer (n = 12, p less than 0.05) or from 63.1 to 78.5 in tuberculosis (n = 7, p less than 0.05), while that of B cells decreased from the high initial level of 34.6 to 26.9 in cancer (n = 7) or from 34.9 to 14.3 in tuberculosis (n = 6, p less than 0.025). The effect of a single dose of the drug tended to disappear by day 8, a peak response being found on day 3 in most cases. With respect to this parameter, an optimal dose was found in a range from 60 to 100 mg. Forphenicinol was rather inhibitory on the NK activity, while it exerted diverse effect on the lymphocyte proliferation. No evidence of adverse effect was observed.