Modulation of 2',5'-oligoadenylate synthetase in patients treated with alpha-interferon: effects of dose, schedule, and route of administration.

The interferon (IFN)-induced intracellular enzyme 2',5'-oligoadenylate (2-5A) synthetase was measured in extracts of peripheral mononuclear cells isolated from patients receiving a 300-fold range of doses of alpha interferon (IFN-alpha). The range of enzyme induction was 2.3- to 5.7-fold. The maximum fold increase varied from individual to individual as did the dose required for maximum enzyme stimulation. The magnitude and endurance of the enzyme response was a function of IFN dose and was unrelated to the duration of treatment or number of injections or to the route of administration. The enzyme assay was a more sensitive indicator of IFN administration than was measurement of the level of circulating IFN. These results substantiate the potential of a clinical 2-5A synthetase assay for monitoring IFN treatment.

Induced proteins in human peripheral mononuclear cells over a range of clinically tolerable doses of interferon-gamma.

This study assessed biologic response modification at three different dose levels (0.15, 1.5, and 15 mg/m2) of interferon-gamma (IFN-gamma) administered by intravenous bolus three times weekly. A final total of 24 patients were evaluable. Dose-limiting toxicity occurred at the highest dose level (15 mg/m2) and included fatigue, leukopenia, and hepatotoxicity. Evaluation of biologic response modification included assessment of 2',5'-oligoadenylate (2-5A) synthetase activity in peripheral mononuclear cells, measurement of serum beta 2-microglobulin and expression of beta 2-microglobulin on monocytes, measurement of monocyte HLA Class II expression (HLA-DR, HLA-DQ), and measurement of hydrogen peroxide generation by monocytes 24 h after the first and fourth IFN-gamma treatments. Significant increases (p less than 0.05) from baseline were seen at 24 h with all parameters except H2O2 generation. Except for enhancement of HLA-DR, even the lowest dose (0.15 mg/m2) augmented synthesis of 2-5A synthetase and HLA proteins. A dose-response effect was noted for changes in serum and monocyte beta 2-microglobulin levels but not for 2-5A synthetase levels or HLA Class II antigen expression on monocytes. After 4 doses administered over 9 days, most parameters remained increased when compared to pretreatment, but were not further enhanced when compared with levels attained after the first dose. The results of this study document the efficacy of IFN-gamma for biological activation over a wide dose range and are consistent with the postulate that immunoregulatory effects of biological therapeutics can be obtained in man at doses substantially less than those that are maximally tolerated. Further documentation of biologic response parameters by IFN-gamma at low doses will be necessary to determine the importance of biologic activation in relation to antitumor activity.

Human biologic response modification by interferon in the absence of measurable serum concentrations: a comparative trial of subcutaneous and intravenous interferon-beta serine.

The effect on a range of biologic responses of interferon-beta serine (IFN-beta ser), administered by either the sc or the iv route, was examined in 16 patients. Despite the absence of IFN in the serum of 13 of 16 patients after sc administration, biologic changes associated with IFN administration occurred. Significant increases in peripheral mononuclear cell surface proteins were evident. Monocyte human leukocyte antigen-DR (HLA-DR) showed a 23% increase in mean fluorescent intensity (P = .04) and a 9% increase in percentage of positive cells (P = .02); lymphocyte OKT10 had an 11% increase in percentage of positive cells (P less than .0001) and a 26% increase in mean fluorescent intensity (P = .002). Natural killer cell activity against the Change target increased by 125% (P = .004). Intracellular activity of 2',5'-oligoadenylate synthetase increased 297% at 24 hours and 226% at 48 hours (P less than .0001). Significant increases in serum concentrations of beta 2 microglobulin (24% at 24 hr and 27% at 48 hr, P less than .0001) and neopterin (85%, P = .0001 and 165%, P = .00001) were observed. These alterations after sc administration were similar quantitatively to those resulting from the same dose of IFN-beta ser given iv. Thus, serum IFN concentrations did not have to be measurable for IFN-beta ser to exert biologic activity. The different effects of two dose levels, 45 X 10(6) IU and 180 X 10(6) IU, also were compared independent of route. The higher dose resulted in greater increases over baseline of 2',5'-oligoadenylate synthetase activity (344% vs. 145% at 24 hr; 231% vs. 83% at 48 hr) and serum neopterin concentrations (185% vs. 99% at 24 hr; 271% vs. 153% at 48 hr). For all the other parameters, there was no significant difference between the two doses.

Phase I trial of human lymphoblastoid interferon with whole body hyperthermia in advanced cancer.

Laboratory studies have shown a potentiation of the biological effects of interferons (IFN) by elevated temperatures (39.5-40.5 degrees C). Based on such observations a Phase I clinical trial involving 17 cancer patients was conducted to assess the toxicity and biological effects of combining whole body hyperthermia (WBH) (40.5 degrees C for 75 min) and IFN. The study design incorporated a treatment schedule which allowed comparisons of WBH alone, to IFN administered i.m., to combinations of the two modalities. Human lymphoblastoid IFN was given for 6 days in weeks, 2, 4, and 6. At least 4 patients were entered at each of three IFN dose levels (1 x 10(6) units/m2; 3 x 10(6) units/m2; 10 x 10(6) units/m2). WBH was delivered on day 1 of week 1, day 6 of week 4, and days 4 and 6 of week 6. IFN was administered 1 h prior to WBH. The schedule used allowed for the development of tachyphylaxis to IFN-induced fever. Maximum temperatures were not significantly higher 24 h post-IFN/WBH than after a comparable number of days of human lymphoblastoid IFN alone. There was no statistically significant difference in toxicity assessments, hematological and hepatic blood parameters, serum IFN levels, or biological response modulation (i.e., 2',5'-oligoadenylate synthetase activity; beta 2-microglobulin levels; natural killer cell cytotoxicity, using K562 target cells and Chang cells) 24 h posttreatment between human lymphoblastoid IFN alone or combined modality therapy. No cumulative toxicity was observed in 6 patients receiving maintenance therapy for up to 1 year. Prior preclinical observations, together with the clinical safety reported in this study, encourage further investigation into the interactions between IFNs and hyperthermia.

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.

Modulation of 2',5'-oligoadenylate synthetase in patients treated with alpha-interferon: effects of dose, schedule, and route of administration.

The interferon (IFN)-induced intracellular enzyme 2',5'-oligoadenylate (2-5A) synthetase was measured in extracts of peripheral mononuclear cells isolated from patients receiving a 300-fold range of doses of alpha interferon (IFN-alpha). The range of enzyme induction was 2.3- to 5.7-fold. The maximum fold increase varied from individual to individual as did the dose required for maximum enzyme stimulation. The magnitude and endurance of the enzyme response was a function of IFN dose and was unrelated to the duration of treatment or number of injections or to the route of administration. The enzyme assay was a more sensitive indicator of IFN administration than was measurement of the level of circulating IFN. These results substantiate the potential of a clinical 2-5A synthetase assay for monitoring IFN treatment.