Therapeutic effectiveness against mopc—315 plasmacytoma of low or high doses of the synthetic thymic hormone THF—γ2 in combination with an “immunomodulating” or a “non—immunomodulating” drug

We reported previously that treatment of mice bearing MOPC—315 plasmacytoma with the drugs L—PAM (phenylalanine mustard) or S—FU (5—fluorouradl), in combination with low doses of THF—γ2, was more effective in increasing their survival time than treatment with the drug alone. We show here that in the combined treatment using a single injection of S—FU followed by multiple (8–15) injections of THF—γ2, the megadoses were more effective than the low doses in increasing the survival time of MOPC—315 tumor—bearing mice. On the other hand, in combination with L—PAM, both low and high doses of THF—γ2 were equally effective. The need for high doses of THF—γ2, when used in combination with 5—FU, could be due to the fact that 5—FU acts as a “non—immuno—modulating” drug and has to be used at a high, immunosuppressive dose.