Experience gained in immunotherapy from the immunopharmacology of BCG leading to a second generation of systemic immunity adjuvants

Even after using the first arms against tumour (surgery and radiotherapy) 70% of solid tumours reappear. Chemotherapy cannot eliminate ‘the last cell’. Specific and/or non specific immunotherapy helps the organism to eliminate the last cells by stimulating its immune capacity.

The different generations of adjuvants, agents of immunotherapy were studied successively. BCG belongs to the first generation of adjuvants. We considered its association with specific immunotherapy (of irradiated tumour cells) and/or chemotherapy (cyclophosphamide), then we analysed the problems of dose and the ways of administration, advantages and disadvantages (stimulation of suppressor cells).

Second generation of adjuvant (Corynebacterium parvum, nucleotids and levamisole) allowed to specify the parameters of the efficiency of adjuvants. They have the same disadvantages as BCG.

Finally the third generation share the following characteristics: their side-effects will be minimal (they will not induce suppressor cells), their action will be limited to stimulate one population of cells only and they will be well defined chemical compounds. Thymosin, Bestatin and MDP belong to this generation. Combinations of adjuvants may also be envisaged with the objective of stimulating a particular mechanism of antitumoural activity.