In vivo priming effects of interferon-beta ser on NK activity of peripheral blood mononuclear cells in cancer patients.

Natural killer (NK) activity was assayed in fresh peripheral blood mononuclear cells (PBMs) from cancer patients receiving interferon (IFN)-beta ser. Patients received a single intravenous injection of IFN-beta ser (90 x 10(6) IU m-2) on alternate days for 2 weeks, followed by a higher dose (180 x 10(6) IU m-2) on the same schedule. PBM NK lysis of K562 target cells was significantly increased in PBMs sampled 24 h after the initial injection (P < 0.05). At the end of the first 2 weeks of the protocol, NK cytotoxic activity of PBMs had fallen below the original baseline levels; the higher IFN dose subsequently given was without effect. However, significant increases in the proportion of CD16+ cells were seen following each injection. A positive correlation was also seen between the increased lytic activity of CD16+ NK cells and the proportion of CD38+ NK cells, but not the proportion of CD56+ NK cells. In vitro IFN-treatment of these in vivo-treated PBMs resulted in a further increase in NK activity. Pre-exposure in vivo to IFN-beta ser seems to prime the PBMs to respond to in vitro stimulation by IFN-gamma, which otherwise had no effect. Phenotypic analysis of PBMs after in vitro exposure to IFN-beta ser showed that the levels of CD16+, CD38+ and CD56+ cells did not change. All the NK activity responding to IFN-beta ser was found in the CD16+ enriched population of PBM, suggesting that it is unlikely that in vivo redistribution of CD16+ subsets representative of NK cells has occurred in the peripheral blood.

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.

A phase I trial of interferon-alpha-2a plus cyclophosphamide, vincristine, prednisone, and doxorubicin.

We conducted a Phase I trial of interferon-alpha-2a (IFN-alpha-2a) plus combination chemotherapy consisting of cyclophosphamide, vincristine, prednisone, and doxorubicin (COPA) in order to determine the maximum dose of IFN-alpha-2a that could be administered without compromising the dose intensity of COPA. Twenty-one patients received IFN-alpha-2a intramuscularly on days 1-5, followed by 600 mg/m2 cyclophosphamide intravenously (i.v.) on day 8; 50 mg/m2 doxorubicin i.v. on day 8; 1.2 mg/m2 vincristine i.v. on day 8; and 100 mg/m2 prednisone orally on days 8-12. IFN doses were escalated between patient groups; 7 patients received 12 x 10(6) U/m2, 11 patients received 6 X 10(6) U/M2, and 3 patients received 12 X 10(6)/m2. Because 79% of the cycles of COPA administered at the third dose level required a delay for hematologic recovery, further patient accrual at this dose level ceased. Grade III or IV granulocytopenia occurred on day 1 in 6, 9, and 0 of the patients treated at the three dose levels. Granulocyte counts rapidly recovered, however, and did not result in a delay in chemotherapy administration on day 8 in 94% of the cycles at the first two dose levels. The mean hematocrit following five cycles of therapy dropped from 40 to 31%. Only two patients required dose reductions due to constitutional symptoms related to the IFN-alpha-2a. Eight responses were observed, including five of five patients with nonHodgkin's lymphomas, one of five with melanoma, one of six with renal cell carcinoma, and one of one with adenoid cystic carcinoma. One patient with metastatic melanoma remains in a complete response on maintenance IFN-alpha-2a for three years. We conclude that 6 X 10(6) U/m2 of IFN-alpha-2a can be administered to cancer patients without significantly compromising the dose intensity of COPA. This observation, and the demonstrated activity of IFN-alpha-2a plus COPA (I-COPA) in low and intermediate grade histology nonHodgkin's lymphomas, provides the basis for the randomized Phase III trial comparing COPA to I-COPA in these neoplasms, which is currently being conducted in the Eastern Cooperative Oncology Group.

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.

Phase II trial of interferon-beta for treatment of recurrent glioblastoma multiforme.

Twelve patients were admitted to a Phase II study on the treatment of recurrent glioblastoma multiforme with interferon-beta (IFN-beta). All patients had previously undergone craniotomy and received a standard course of radiation therapy. Recurrence was inferred from enlargement of the lesion on computerized tomography (CT) scanning and in each case was confirmed by CT-guided stereotaxic biopsy. Treatment consisted of combined intravenous (10 X 10(6) IU/day) and intratumoral (1 X 10(6) IU every other day) administration of IFN-beta over three 10-day cycles. This regimen was well tolerated, with toxicity requiring temporary dose modifications in five patients. As judged from data from historical cases, however, the patients admitted to this study demonstrated no clear improvement in mean survival time. The findings of this study also emphasize the importance of distinguishing between radiation necrosis and tumor recurrence.

Phase I evaluation of a synthetic mutant of beta-interferon.

A synthetic mutant of beta-interferon, produced by recombinant DNA technology, was prepared with serine substituted for the naturally occurring cysteine at amino acid 17. This molecule, after purification to homogeneity, was evaluated in 23 patients with cancer for tolerated doses, safety, and pharmacokinetics. Each patient was begun on twice weekly administration, one dose i.m., then an identical dose i.v. Doses, escalated weekly, were tolerated by 9 of 12 patients at 100 X 10(6) units i.m., 11 of 14 patients at 100 X 10(6) units i.v., and 8 of 10 patients receiving i.v. doses of 200 X 10(6) units. Fever (greater than or equal to 38.9 degrees C), the commonest cause for ceasing dose escalation, occurred in 11 of 13 patients who developed limiting i.v. toxicity and 6 of 11 who developed limiting i.m. toxicity. Patients who did not have progressive cancer after completion of dose escalation received five consecutive daily doses at their maximum tolerated single dose by each route, i.m. and i.v. These two 5-day treatments were given without difficulty. All patients treated with 300 X 10(6) units or less, i.m. (n = 13) or i.v. (n = 10), were able to receive five daily doses without limiting toxicity. Peak serum titers occurred immediately after i.v. administration and declined in an exponential manner thereafter. Despite absence of measurable titers in serum after i.m. injection, fever and significant (P less than 0.05) depression of WBC and platelet counts, serum calcium, and serum cholesterol occurred (prestudy to maximum tolerated dose). An immunoglobulin antibody to beta-interferon, detected by enzyme-linked immunoabsorbent assay, developed in 17 of 23 patients. Neutralizing activity (titer 10(2] was found in only 1 of 23 patients. No immune-mediated sequelae (symptomatic or renal) were identified. Further Phase I and II trials with this molecule will determine whether it will prove to have a better therapeutic index or different spectrum of therapeutic activity from alpha-interferon or gamma-interferon.