The present status of clinical studies with interferons in cancer in Britain.

Although the evaluation of cloned interferons is now under way, the only clinical results currently available from U.K. studies in cancer come from trials using the (Wellcome) lymphoblastoid preparation. Dose toxicity studies for intravenous and intramuscular administration are now complete and show that on a daily schedule the maximum tolerated dose intramuscularly is 12 x 10(6) units (12 Mu) whereas by 24 h intravenous infusion doses of up to 300 Mu may be given without undue toxicity. A programme of studies has been initiated to assess the efficacy of lymphoblastoid interferon in a variety of tumours. A number of therapeutic responses have been seen but only one study, in malignant melanoma, has completed patient entry. In this series of 16 patients who had metastatic disease and had failed on conventional cytotoxic therapy one patient experienced a remission for 8 months as a result of interferon administration. In another study the combination of interferon with conventional cytotoxics is being evaluated in advanced breast cancer. Preliminary results indicate that the combination is well tolerated but it is too early to detect any therapeutic advantage from combining the two modalities.