Effects of human recombinant alpha 2 arg-interferon and gamma-interferon on human breast cancer cell lines: dissociation of antiproliferative activity and induction of HLA-DR antigen expression.

Human recombinant gamma-interferon (rhu-IFN-gamma) and human recombinant alpha-interferon (rhu-IFN-alpha 2 arg) with a chemical purity of over 95% were compared for their antiproliferative and HLA-DR-inducing activity in five human breast cancer cell lines (BT 20, ZR 75.1, MCF 7, 734B, Hs578T). Cytostatic effects on tumor cells were evaluated in monolayer cultures. HLA-DR antigen expression was examined by an indirect immunofluorescence technique using two different anti-HLA-DR monoclonal antibodies (anti-HLA-DR, VID-1) against framework determinants. rhu-IFN-gamma and rhu-IFN-alpha 2 arg differed in their antiproliferative efficiency in terms of both dose dependency and the spectrum of sensitive target cells. Combinations of rhu-IFN-gamma and rhu-IFN-alpha 2 always resulted in higher cytostatic effects. HLA-DR expression was exclusively inducible by rhu-IFN-gamma and did not correspond to its antiproliferative activity. Furthermore, HLA-DR expression did not depend on proliferation but did require intact RNA and protein syntheses as shown by inhibition with cycloheximide and actinomycin D. HLA-DR antigen expression in mammary cancer lines was dependent on time, dose, and the continued presence of rhu-IFN-gamma. Thus, our data suggest that in particular combinations type I and type II interferons might be useful in the treatment of breast cancer because they provide effective cytostatic and cell membrane-modulating properties.

Recombinant tumour necrosis factor alpha administered subcutaneously or intramuscularly for treatment of advanced malignant disease: a phase I trial.

The pharmacokinetics, toxicity and biological effects of subcutaneous and intramuscular treatment of cancer patients with recombinant tumour necrosis factor alpha (rTNF-alpha) was investigated. 17 patients suffering from refractory malignant disease were treated with either 1.0 micrograms/m2, 10 micrograms/m2 or 100 micrograms/m2 rTNF-alpha. Vital signs, peripheral blood cell counts, TNF and interferon (IFN) gamma serum levels, neopterin, beta 2-microglobulin, C reactive protein (CRP) and cortisol levels were measured immediately before and 2, 12, 24, 48 and 168 h after the first administration of rTNF-alpha. Tumour response was evaluated after 4 and 12 weeks of treatment. The pharmacokinetics followed the same characteristics as those reported for other cytokines. Major toxicities were dose dependent and comprised fever, constitutional symptoms and hypotension. TNF dependent changes were observed in serum levels of IFN-alpha, CRP, neopterin, beta 2-microglobulin, cortisol and white blood cell counts. No objective tumour response was observed. This study indicated that rTNF-alpha administered subcutaneously or intramuscularly results in measurable TNF serum levels, significant toxicity and biological response in absence of clinical efficacy in patients with advanced cancer.

Relationship of interferon-gamma and neopterin levels during stimulation with alloantigens in vivo and in vitro.

We have recently shown that interferon-gamma is capable of activating the key enzyme of pterin biosynthesis in macrophages. This leads to excretion of the stable degradation product neopterin. In this article we present experimental evidence suggesting that stimulation of T cells by alloantigens is associated with release of interferon-gamma--which, in the case of rejection, is locally restricted and not always detectable in the bloodstream. Neopterin induced by this lymphokine, however, readily penetrates tissue barriers and is detectable in the serum. This conclusion is based on two different sets of observations: (1) If supernatants of MLCs are compared with sera from patients with documented acute rejection episodes for their interferon-gamma and neopterin levels, a marked gradient is observed to exist between interferon levels measured in vitro and in vivo; this is not the case for neopterin for which comparable levels were seen. (2) Detection of interferon-gamma in sera of allograft recipients invariably precedes an increase of neopterin; on the other hand, increasing neopterin counts are also seen in the absence of detectable interferon-gamma levels in the serum. It thus appears that although interferon-gamma release during allograft rejection is primarily restricted to the tissue, evaluation of certain metabolites of interferon-dependent metabolic pathways enables definition of its endogenous release. Whereas interferon gamma represents a less reliable marker in the monitoring of rejection episodes, it might offer an additional means to differentiate rejection from systemic infections. Such a discrimination can not be achieved with the neopterin marker.

A biological approach to optimize interferon treatment in hairy cell leukemia.

Progress with the clinical application of interferons to neoplastic diseases has been slow and complicated by the need for attention to a new spectrum of therapeutic and toxic effects manifested by the interferons. In this report, we present a new approach to define clinically effective but atoxic doses of interferon-alpha for treatment of hairy cell leukemia. In order to find in vivo biologically active interferon doses, the biochemical marker neopterin was selected as a means to assess a cellular interferon response in vivo. Subcutaneous administration of minimal doses of recombinant interferon-alpha-2 (5-8 X 10(5) U/day), which induced maximum neopterin release in serum and urine, proved to be clinically effective: Eight of nine patients responded to this dose regimen. This response rate was comparable to that of a conventional dose schedule (3 X 10(6) U/sqm/day) which was also applied to nine patients (eight responders). Whereas no difference in the clinical efficacy between the two therapeutic strategies could be established, toxicity was clearly confined to the conventional dose regimen. These preliminary results suggest that at least in hairy cell leukemia the therapeutic dose range of interferon can be separated from the toxic.

Interferon-gamma for the treatment of metastatic renal cancer: dose-dependent stimulation and downregulation of beta-2 microglobulin and neopterin responses.

Considering rIFN-gamma as a potent biological response modifier (BRM), we started an open phase II trial with rIFN-gamma in patients with advanced renal cell carcinoma (RCC). For optimization of the dose and schedule of rIFN-gamma, two biochemical serum markers, neopterin and beta-2 microglobulin, were chosen to monitor the biological response. In order to test the magnitude and kinetics of rIFN-gamma-induced neopterin and beta-2 microglobulin release in the serum, rIFN-gamma was administered thrice at three different dose levels in a randomly assigned order (0.01; 0.1; 0.5 mg). Neopterin and beta-2 microglobulin were assessed by means of commercially available radioimmunoassays. The results revealed: 1) strong, reproducible and dose-dependent increments of both markers after the first injection 2) downregulation of the magnitude of neopterin responses with repeated injections at each of the three dose levels tested, and 3) a dose-dependent downregulation of the magnitude of beta-2 microglobulin responses and of serum baseline values at the highest dose level tested. From these data, we conclude that both the dose and schedule might be of importance for optimization of biological responses to exogenously applied rIFN-gamma.

Phase II trial of recombinant interferon alpha-2C in metastatic renal cell carcinoma.

A total of 18 patients with advanced metastatic renal cell cancer were treated with recombinant interferon alpha-2C (rIFN alpha-2C) at daily doses of 10 X 10(6) IU by intramuscular injection. All patients had evaluable metastatic lung, liver, or abdominal disease as measured by radiographic or computerized tomographic scans. In 2 of the 18 patients an objective response (1 CR, 1 PR) with a duration of +28 and 12 months, respectively was achieved. A 25$ to 50$ decrease in tumor measurements (MR) was seen in 2 additional patients; in 3 cases a stabilisation of the disease (SD) was observed, whereas it progressed in 11. 3/4 responding patients (including MR) and all 3 cases with SD had measurable disease in the lungs as predominant site of metastatic disease. Additional clinical characteristics of patients exhibiting response or SD to IFN therapy included prior nephrectomy, favourable initial performance status and limited metastatic disease. No serious haematologic or irreversible organ toxic effects were attributed to interferon. Several patients, however, had constitutional symptoms, and major dose reductions due to CNS toxicity became necessary in two. Further studies are warranted to evaluate the use of interferons in combination with cytotoxic drugs or other biologic response modifiers.

[Interferon alpha 2C in the treatment of 2 patients with AIDS-associated Kaposi sarcoma]. / Interferon alpha 2C in der Behandlung zweier Patienten mit AIDS-assoziiertem Kaposi-Sarkom.

Two patients with AIDS and histologically confirmed Kaposi's sarcoma were treated with 3 X 10(6) U/m2 interferon alpha 2C (rIFN alpha 2C) subcutaneously three times a week. In both cases remissions (7 weeks and more than 9 months) of the tumour lesions were achieved and in one case pretherapeutic moderate thrombocytopenia improved. The positive serum antibody titres to HTLV III-virus showed no conversion. Except for fever (below 39 degrees C) during the first two weeks of IFN treatment in both patients, therapy-requiring hypotonia, mild depression, leucopenia (WHO grade 1) and thrombocytopenia (WHO grade 2) in one patient, no side effects were observed. All the above-mentioned features were reversible after termination of treatment. Further studies to optimize the dosage of rIFN alpha 2C and its time schedule in the treatment of Kaposi's sarcoma in patients with AIDS are recommended.

[Defects in the prostaglandin system. VIII. A pathologic thrombocyte population in myeloproliferative syndrome, which forms no thromboxane from exogenous arachidonic acid]. / Defekte im Prostaglandinsystem. VIII. Eine pathologische Thrombozytenpopulation bei myeloproliferativem Syndrom, die aus exogener Arachidonsäure kein Thromboxan bildet.

In 2 out of 29 patients suffering from the myeloproliferative syndrome a lack of thromboxane conversion by platelets from exogenous arachidonic acid was discovered. In one patient PGE2 (30.9%) and 12-HETE (12-Hydroxyeicosatetraenoic acid) (42.8%) were formed instead, whilst in the other patient 12-HETE (72.9%) was the main metabolic product. In both the patients, serum and plasma TXB2, as well as malondialdehyde, were quite low. It is claimed that this phenomenon is due to the expression of a pathological population of platelets related to the disease.

Interferon-alpha-2C in the treatment of advanced hairy cell leukaemia. Results of a phase II trial.

The efficacy of recombinant interferon-alpha 2 in the treatment of advanced hairy cell leukaemia is investigated in 31 patients. Preliminary results show a complete and partial response rate of 69%. An optimal dose study utilizing maximal stimulation of an interferon-dependent pathway was carried out in 5 patients. The optimal dose of the order of 5 X 10(5) IU/day is effective and without side-effects. Interferon treatment did not enhance natural killer cell activity and therefore a direct mode of action upon tumour cells is proposed.

[Interferon (IFN) therapy (recombinant IFN-alpha-2C or recombinant IFN-gamma) in metastasized hypernephroma]. / Interferon-(IFN-) Therapie (rekombinantes IFN-alpha-2C oder rekombinantes IFN-gamma) beim metastasierten Hypernephrom.

Recombinant interferon-alpha-2C (rec. IFN alpha-2C) and recombinant interferon-gamma (IFN-gamma) was studied in 12 patients with metastasized renal cell carcinoma. 8 patients were treated with IFN-alpha-2C: 1 patient achieved a complete remission, 2 patients showed mixed responses, and 2 had stabilisation of their disease. In 3 patients progressive disease was observed. IFN-gamma was studied in 4 patients; 2 patients showed stable and 2 progressive disease. Side effects of IFN-alpha treatment included influenza-like symptoms, moderate hematological toxicity and neurological symptoms. During treatment with IFN-gamma similar side effects were observed, although fever generally was more pronounced. All symptoms ceased after dosis reduction or discontinuation of treatment.

Phase I study of recombinant human tumor necrosis factor-alpha in patients with advanced malignancies.

A clinical phase I trial with recombinant human tumor necrosis factor-alpha (rTNF-alpha) was performed in 30 patients with advanced malignancies. The maximal tolerated dose (MTD) by 3 times weekly intramuscular (i.m.) application was 150 micrograms m-2. Main subjective toxicities including chills, fever, hypotension, fatigue, and anorexia were dose-related. In addition, transient changes in hematologic parameters and lipid metabolism were noted. Two out of 25 evaluated patients showed a minor tumor response after eight weeks of therapy. There was evidence for an improvement of in vivo immuneresponsiveness as revealed from positive delayed type hypersensitivity (DTH) skin tests of 3 out of 6 pretherapeutically anergic patients. We conclude from this phase I trial that rTNF-alpha can be safely administered at doses up to 150 micrograms m-2 i.m., 3 times weekly, without evidence of cumulative toxicity in long-term treatment.

Alpha-interferon induces remission in hairy cell leukemia without enhancement of natural killing.

The number of large granular lymphocytes (LGL) and the capacity of peripheral blood mononuclear cells (PBMC) to lyse K 562 target cells in a natural killer (NK)-like fashion was evaluated in seven hairy cell leukemia (HCL) patients undergoing treatment with recombinant interferon-alpha-2 (rIFN-alpha-2). In HCL patients, whose peripheral blood showed high numbers (greater than or equal to 15 X 10(3)/microliters) of leukemic cells the number of LGL and their capacity to lyse K 562 tumor target cells were very low prior to treatment but increased significantly (p less than 0.05) following interferon (IFN) therapy. In patients with low numbers of hairy cells (HC) in their peripheral blood, both these parameters were higher and remained largely unaffected throughout IFN treatment. In vitro, HC proved to be completely insensitive to natural killing when tested against unstimulated and IFN-activated LGL from healthy donors. These results fail to support the concept of IFN-mediated enhancement of host antitumor actions, responsible for the favourable clinical results in HCL.

[Interferon/Controlled study in 3-year survival of patients with osteosarcoma (author's transl)]. / Verträglichkeitsprüfung von humanem Lymphoblasten-Interferon. Kontrollierte Studie bei 8 Osteosarkom-Patienten mit 3-Jahres-Uberleben.

In eight patients with osteosarcoma we conducted a controlled tolerance study with human lymphoblast interferon. Interferon was applied for 12 months and the control period after stopping interferon has lasted 12-42 months up to now. 4 out of 8 patients who received interferon did not show any adverse reaction concerning clinical and laboratory tests during the course of a 1-year application and during the follow-up period, resp. Only reversible thrombopenias and an increase in the alpha 2-globulins fraction were observed in the interferon and in the control group, resp. All of the 8 patients have up to now survived tumor-free.

[Therapy with interferon (recombinant IFN-alpha-2C) in myeloproliferative diseases with severe thrombocytoses]. / Therapie mit Interferon (rekombinantes IFN-alpha-2C) bei myeloproliferativen Erkrankungen mit exzessiven Thrombozytosen.

15 patients with myeloproliferative diseases and thrombocythaemia (7 Polycythaemia vera, 5 essential thrombocythaemia, 3 chronic myelogenous leukaemia) were assigned to a therapy with recombinant interferon (recombinant IFN-alpha-2C) in a prospective, controlled trial. Under therapy all patients showed a significant decrease in thrombocyte values. 51% of the patients revealed thrombocyte values within the normal range after 3 months of IFN therapy. Noted side effects of IFN therapy were dose-dependent and clinically well tolerated by the patients.

Phase II results with recombinant interferons: renal cell carcinoma and malignant melanoma.

There is as yet no effective treatment for renal cell carcinoma and metastasizing malignant melanoma. This fact, coupled with in vitro investigations showing growth inhibitory or cytotoxic effects of interferon (IFN) on renal cell carcinoma and melanoma cell lines, led to phase II clinical trials with recombinant (r) IFN-alpha 2C and rIFN-gamma. So far 8 patients with renal cell carcinoma have been treated with IFN-alpha 2C and 3 patients with rIFN-gamma. There has been one complete response to IFN-alpha 2C, two mixed responses and one partial response. One patient on rIFN-gamma has stable disease and the other 2 have progressed. Eleven patients with metastasizing malignant melanoma were treated with IFN-alpha 2C. One patient achieved a complete remission and 3 others had stable disease which later progressed in 2 of them. Side-effects were reversible.

Interferon-alfa corrects thrombocytosis in patients with myeloproliferative disorders.

During previous therapeutic trials with interferon, decreased levels of peripheral platelet counts have been observed. Taking advantage of this effect, we investigated the efficacy of recombinant interferon (rec-IFN) in the treatment of thrombocytosis in myeloproliferative diseases. A total of 15 patients with polycythemia vera, essential thrombocytosis, or chronic myeloid leukemia received rec-IFN-alfa at initial doses of 25-70 x 10(6) units/week; maintenance therapy following week 8 of treatment consisted of 20-35 x 10(6) units/week rec-IFN. Observation periods ranged from 24 to 48 weeks. Significant reductions in the number of platelets were noted in all cases; 12/15 patients achieved platelet counts below 440 x 10(9)/l and maintained those normal values for at least 4 weeks. The number of bone marrow megakaryocytes, which had been increased prior to treatment, diminished during rec-IFN therapy, while the previously shortened platelet half-life further decreased with rec-IFN treatment. During rec-IFN-induced remission, the plasma levels of platelet factors, the activity of natural killer cells, and platelet aggregation showed changes between slight improvement and normal values. Severe side effects were only observed with the highest rec-IFN doses; dosage adjustments were effective in improving or eliminating all treatment-related symptoms. Rec-IFN may prove to be a valuable therapeutic alternative to cytostatic treatment of thrombocytosis in myeloproliferative disorders.

Interferon-alpha-2 in the treatment of idiopathic myelofibrosis.

We investigated the effect of human recombinant DNA-derived IFN-alpha-2 given in a dose of 1-2 X 10(6) units daily by subcutaneous injection to five patients with advanced idiopathic myelofibrosis (IM). Transfusion dependent anemia and symptomatic splenomegaly were taken as inclusion criteria for this pilot study. Two patients succumbed, one and three months after starting interferon-treatment because of pneumonia and traumatic cranial injury, respectively. While on IFN-treatment no improvement of cytopenia or reduction of splenomegaly was seen in four of the patients. In one patient, however, the requirement for erythrocyte transfusions decreased from 5 to 1.7 monthly upon IFN-treatment. After two, four and six months respectively IFN-treatment had to be stopped in these cases because of progressive thrombocytopenia and/or neutropenia. These observations suggest, that IFN-alpha might be of only marginal value in the treatment of advanced idiopathic myelofibrosis.

[Interferon-alpha in the treatment of hematologic neoplasms]. / Interferon-alpha in der Behandlung hämatologischer Neoplasien.

This report aims to review briefly the current status of treatment of haematological malignancies with interferon-alpha (IFN-alpha). Overall hairy cell leukemia and chronic myelogenous leukemia appear to be most sensitive to IFN-alpha. We started to investigate, how interferon exerts its antileukemic activity and in which way interferon therapy can be optimized. Our preliminary results fail to support the view of interferon mediated enhancement of host responses. They rather indicate direct effects of IFN on leukemic cells in vitro. By means of IFN-dependent biological markers (e.g. beta-2-microglobulin, neopterin) clinically effective but atoxic doses of IFN-alpha could be defined for HCL and CML. In final conclusion, the recent studies on the clinical efficacy of IFN-alpha revealed its potent antitumoral effect in hematological malignancies. However, the further proof of the potential benefit of IFN treatment versus conventional therapeutic strategies remains to be elucidated.

[Results of a phase II study on the treatment of hairy cell leukemias with various doses of alpha-2-recombinant interferon]. / Ergebnisse einer Phase-II-Studie zur Behandlung von Haarzell-Leukämien mit unterschiedlichen Dosen von alpha-2-rekombinantem Interferon.

Hairy-cell leukemia has been shown to be extraordinary sensitive to treatment with alpha-interferon. In order to define clinically effective interferon doses associated with minimal toxicity two different dose regimens were applied in this clinical trial: firstly, a conventional dose schedule, and secondly, a biologically defined dose regimen. For dose finding in the latter group, neopterin, a GTP degradation product produced by macrophages under control of interferon, was chosen. Six patients (Group A) received conventional doses of recombinant interferon--alpha-2 (rIFN-alpha-2) 3 X 10(6) U/sqm/daily by the subcutaneous route. Five patients (Group B) were treated with the minimal dose of rIFN-alpha-2 which had previously been shown to induce maximum neopterin levels in urine. Already interferon doses in the range of 3 to 5 X 10(5) U/sqm2/daily administered subcutaneously proved to be sufficient for triggering maximum neopterin excretion in the urine. After six months of interferon treatment all patients were evaluable. At this time both doses regimens proved to be effective in terms of their anti-leukemic activity, but differed significantly in toxicity, which was only seen in Group A patients.