Clinical and biological effects of recombinant interferon-beta administered intravenously daily in phase I trial.

Interferon-beta serine (IFN-beta ser) was administered intravenously (i.v.) daily for 14 days at doses of 3, 10, 30 X 10(6) units to 19 patients. In this Phase I trial, IFN-beta ser was tolerated without limiting fever or subjective toxicities. At 30 X 10(6) units, 3 patients developed hematologic toxicity and dose escalation was thus terminated. No patient developed detectable binding or neutralizing antibody to IFN-beta. A significant (p less than 0.006) increase in serum beta 2-microglobulin and a significant (less than 0.005) increase in 2',5'-oligoadenylate synthetase (2-5A) in peripheral mononuclear cells were identified. Increase in these proteins did not correlate with dose or with the disappearance of serum IFN over the first 5 h after injection. Two patients, one with renal carcinoma and one with melanoma, had objective responses. This trial further confirms safety and biological potency of this synthetic mutant of IFN-beta.