A phase I clinical tolerance study of rDNA alpha 2 human interferon in patients with non-reticuloendothelial system...

Twenty-seven patients with non-reticuloendothelial malignancies were treated with a single intramuscular injection of recombinant leukocyte alpha 2 interferon (rIFN) to assess clinical tolerance and define a maximum tolerated dose. A single patient in each of six increasing dosage groups (0.3 X 10(6) IU, 1 X 10(6) IU, 3 X 10(6) IU, 10 X 10(6) IU, 30 X 10(6) IU, 100 X 10(6) IU) received a low dose (0.01 X 10(6) IU) and served as a control for subjective and objective toxicity measurements. Severe fatigue proved dose-limiting at 100 X 10(6) IU, and all dosages above 3.0 X 10(6) IU produced one or more signs or symptoms, which typically resembled a 'flu-like' syndrome. Objective toxicity was mild to moderate (leukopenia, thrombopenia) and no toxicities were found not already known from work with interferon obtained directly from leukocytes. Evidence of an antitumor effect was apparent in 3/19 evaluable patients.