Protection of mice against syngeneic lymphomata: II. Collaboration between drugs and antibodies.

Rabbit anti-mouse tumour cell serum can be made tumour specific by absorption with normal mouse cells and in an in vivo protection test can be shown to have a measurable protective effect on mice against a given number of lethal doses of a lymphoma. Some drugs have been evaluated in this system. When drug treatment is combined with antibody treatment much greater protection can be obtained than when the same amounts of drug or antibody are used alone. It is preferable to administer drug before antibody and with the combined schedule it is possible in the test model to protect all mice from tumour growth, even allowing the tumour up to 48 h "get-away" time before starting treatment.