Initial evaluation of human lymphoblastoid interferon in patients with advanced malignant disease

A study was carried out to establish the maximum tolerated dose of human lymphoblastoid interferon and to define its side effects when given by intramuscular injection. Pyrexia limited the initial dose to a maximum of 3 megaunits/m2 body surface area, but tolerance to this effect developed over 4 to 5 days and the dose was then increased to 5 to 7.5 megaunits/m2; subjective disturbance prevented further increase in dose, but 2.5 to 5.0 megaunits/m2 daily was well tolerated and appears suitable for long-term administration. Other side effects were hypertension, hypotension, myelosuppression, and disturbance of liver-function tests. All toxic effects were reversible on stopping the interferon. Two patients showed evidence of tumour regression, indicating that further trials are justified to define the extent of anticancer activity.