Pharmacologic factors and manipulation of immunity systemic adjuvants in cancer therapy.

Because of the experimental and clinical studies which have been extensively conducted with bacillus Calmette-Guérin (BCG) as a systemic adjuvant in cancer immunotherapy, we have analyzed the main factors and conditions which determine its beneficial action and have underlined some of these (eg, the dose factor which controls the amplification of suppressor cells which is probably responsible for failures and even the possible tumor-enhancing effect of immunotherapy). Knowing those factors and conditions, we have been able to establish a systematic immunopharmacologic study of systemic immunity adjuvants, which has resulted in the discovery of agents whose actions are more rapid than that of BCG on one or a few populations of cells involved in immunity and which, unlike BCG, do not induce suppressor cell amplification. This amplification may explain the difference in the results obtained with this mycobacterium in various clinical immunotherapy trials in which it was applied differently. It is proposed to combine these mono- or pauc-functional adjuvants in order to try to obtain all of the beneficial effects of BCG without the amplification of suppressor cells.