A preliminary report on the effects of methanol extraction residue of BCG (MER) on cancer patients.

Twenty-seven patients with malignant neoplasia were injected intradermally with the methanol extraction residue (MER) fraction of tubercle bacilli. Two schedules of treatment were used: every other week and once a month; 1-10 courses of MER were administered to the patients. The skin reactivity to 3 recall antigens, as well as to the injected MER itself, was used to monitor the immune response. Improvement of skin reactivity occurred in 9 of 18 patients tested with recall antigens. Five of 6 patients treated every other week improved in their immune capacity whereas only 4 of 12 patients improved on the monthly schedule. Thus, repeated injections given every other week were more effective in increasing the cutaneous reactivity than monthly injections of MER. The side-effects of MER treatment were tolerable.