A phase I trial of recombinant human tumor necrosis factor and interferon-gamma: effects of combination cytokine administration in vivo

Programmable bacteria synergize with PD-1 blockade to overcome cancer cell-intrinsic immune resistance mechanisms

Interferon-γ (IFN-γ) is a potent cytokine critical for response to immunotherapy, yet conventional methods to systemically deliver this cytokine have been hindered by severe dose-limiting toxicities. Here, we engineered a strain of probiotic bacteria that home to tumors and locally release IFN-γ. A single intratumoral injection of these IFN-γ-producing bacteria was sufficient to drive systemic tumor antigen-specific antitumor immunity, without observable toxicity. Although cancer cells use various resistance mechanisms to evade immune responses, bacteria-derived IFN-γ overcame primary resistance to programmed cell death 1 (PD-1) blockade via activation of cytotoxic Foxp3-CD4+ and CD8+ T cells. Moreover, by activating natural killer (NK) cells, bacteria-derived IFN-γ also overcame acquired resistance mechanisms to PD-1 blockade, specifically loss-of-function mutations in IFN-γ signaling and antigen presentation pathways. Collectively, these results demonstrate the promise of combining IFN-γ-producing bacteria with PD-1 blockade as a therapeutic strategy for overcoming immunotherapy-resistant, locally advanced, and metastatic disease.

Treatment of Recurrent Sarcoma of the Extremities by Isolated Limb Perfusion Using Tumor Necrosis Factor Alpha and Melphalan

Background

24-60% of patients with soft tissue sarcoma shows local recurrences after treatment of the primary tumor. The event is associated with a high incidence of macroscopic or microscopic metastases and a poor survival. Our goal is to preserve a patient's functional limb by treating such cases with isolated limb perfusion (ILP) with recombinant human tumor necrosis factor alpha (rHu TNF-α) and melphalan, which have demonstrated a potent antitumor activity in vivo and in vitro studies.

Methods

During the period November 1991 to November 1995, 10 patients with unresectable recurrent soft tissue sarcoma of the limb were treated by ILP at intermediate hyperthermia (40-40.5 °C) with rHu TNF-α and melphalan. Two patients also received recombinant interferon gamma (rIFN-γ) before and during ILP. We used a range of 2-4 mg for rHu TNF-α and 50-100 mg of melphalan. rIFN-γ was administered on days -2 and -1 (15x106 IU) subcutaneously and the same dose was injected in the arterial line during ILP.

Results

No perioperative surgical complication was observed. Local toxicity was moderate (grade I or II); general toxicity was observed in 6 patients (2 grade I and 4 grade III). Complete response was obtained in 7 cases; 2 patients had a partial response and finally 1 was a nonresponder and showed local progression, which required surgical amputation. Tumor necrosis (observed in 5 cases) was maximal in 4 patients (80-100%) and absent in the patient who had local progression.

Conclusions

The results we obtained with the treatment of soft tissue sarcoma confirm the efficacy of ILP as a limb-sparing methodology for unresectable recurrences. Furthermore, rHu TNF-α and melphalan confirmed their antitumor activity when associated with hyperthermia. Amputation or disarticulation may be reliable as a second-choice treatment for these patients.

The meteorology of cytokine storms, and the clinical usefulness of this knowledge

The term cytokine storm has become a popular descriptor of the dramatic harmful consequences of the rapid release of polypeptide mediators, or cytokines, that generate inflammatory responses. This occurs throughout the body in both non-infectious and infectious disease states, including the central nervous system. In infectious disease it has become a useful concept through which to appreciate that most infectious disease is not caused directly by a pathogen, but by an overexuberant innate immune response by the host to its presence. It is less widely known that in addition to these roles in disease pathogenesis these same cytokines are also the basis of innate immunity, and in lower concentrations have many essential physiological roles. Here we update this field, including what can be learned through the history of how these interlinking three aspects of biology and disease came to be appreciated. We argue that understanding cytokine storms in their various degrees of acuteness, severity and persistence is essential in order to grasp the pathophysiology of many diseases, and thus the basis of newer therapeutic approaches to treating them. This particularly applies to the neurodegenerative diseases.

Vascular-targeted TNFα and IFNγ inhibits orthotopic colorectal tumor growth

Background

Tumor necrosis factor alpha (TNFα) and interferon gamma (IFNγ) were originally identified to show potent anti-tumor activity and immunomodulatory capability. Unfortunately, several clinical studies of relevant cancer therapy did not observe significant response in maximum tolerated dose whether given alone or in combination. We have identified a tumor vasculature homing peptide (TCP-1 peptide) which targets only the vasculature of colorectal tumors but not normal blood vessels in animals and humans. In the current study, the antitumor effect of TCP-1/TNFα and TCP-1/IFNγ alone or in combination was studied in orthotopic colorectal tumor model.

Methods

TCP-1/TNFα and TCP-1/IFNγ recombinant proteins were prepared and i.v. injected to study the in vivo anticancer effect in orthotopic colorectal tumor model. Tumor apoptosis was determined by TUNEL staining and cleaved caspase-3 immunofluorescent staining. Tumor infiltrating lymphocytes were analyzed by immunofluorescent staining and flow cytometry. Western-blot was performed to examine the expression of proteins. Cell apoptosis was measured by Annexin V/PI flow cytometry.

Results

Targeted delivery of TNFα or IFNγ by TCP-1 peptide exhibited better antitumor activity than unconjugated format by inducing more tumor apoptosis and also enhancing antitumor immunity shown by increased infiltration of T lymphocytes inside the tumor. More importantly, combination therapy of TCP-1/TNFα and TCP-1/IFNγ synergistically suppressed tumor growth and alleviated systematic toxicity associated with untargeted therapy. This combination therapy induced massive apoptosis/secondary necrosis in the tumor.

Conclusions

Taken together, our data demonstrate TCP-1 is an efficient drug carrier for targeted therapy of colorectal cancer (CRC). TCP-1/TNFα combined with TCP-1/IFNγ is a promising combination therapy for CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0944-3) contains supplementary material, which is available to authorized users.

Induction of circulating phospholipase A(2) by intravenous administration of recombinant human tumour necrosis factor

We have examined the effects of intravenous infusion of recombinant human tumour necrosis factor (rh-TNF) on serum activity of phospholipase A(2) (PLA(2)) in patients with malignancies. Nine patients received a 24 h continuous intravenous infusion ranging from 1.0 x 10(5) U/m(2) to 3.0 x 10(5) U/m(2); 14 patients received a 5 day continuous intravenous infusion ranging from 0.5 x 10(5) U/m(2)/day to 3.0 10(5) U/m(2)/day. Twenty one of 23 patients responded with marked increases in serum PLA(2) activity that were detectable 3 h after the beginning of the rh-TNF infusion and reached maximum levels at 18 h with a mean increase of 16.2-fold. In patients receiving a 5 day rh-TNF infusion, the highest levels of PLA(2) were observed after the first day of infusion. Serum PLA(2) activity declined continuously to 2.9-fold above baseline at the end of the infusion. A significant correlation was noted between the dose of infused rh-TNF and the maximum increase in PLA(2) activity. To our knowledge, this is the first time that an association between intravenous TNF administration and induction of circulating PLA(2) in man has been established.

Systemic use of tumor necrosis factor alpha as an anticancer agent

Tumor necrosis factor-α (TNF-α) has been discussed as a potential anticancer agent for many years, however initial enthusiasm about its clinical use as a systemic agent was curbed due to significant toxicities and lack of efficacy. Combination of TNF-α with chemotherapy in the setting of hyperthermic isolated limb perfusion (ILP), has provided new insights into a potential therapeutic role of this agent. The therapeutic benefit from TNF-α in ILP is thought to be not only due to its direct anti-proliferative effect, but also due to its ability to increase penetration of the chemotherapeutic agents into the tumor tissue. New concepts for the use of TNF-α as a facilitator rather than as a direct actor are currently being explored with the goal to exploit the ability of this agent to increase drug delivery and to simultaneously reduce systemic toxicity.

This review article provides a comprehensive overview on the published previous experience with systemic TNF-α. Data from 18 phase I and 10 phase II single agent as well as 18 combination therapy studies illustrate previously used treatment and dose schedules, response data as well as the most prominently observed adverse effects. Also discussed, based on recent preclinical data, is a potential future role of systemic TNF-α in combination with liposomal chemotherapy to facilitate increased drug uptake into tumors.

Transcriptional control of viral gene therapy by cisplatin

Ionizing radiation (IR) and radical oxygen intermediates (ROIs) activate the early growth response-1 (Egr1) promoter through specific cis-acting sequences termed CArG elements. Ad.Egr.TNF.11D, a replication-deficient adenoviral vector containing CArG elements cloned upstream of the cDNA for human recombinant TNF-alpha was used to treat human esophageal adenocarcinoma and rat colon adenocarcinoma cells in culture and as xenografts in athymic nude mice. Cisplatin, a commonly used chemotherapeutic agent, causes tumor cell death by producing DNA damage and generating ROIs. The present studies demonstrate induction of TNF-alpha production in tumor cells and xenografts treated with the combination of Ad.Egr.TNF.11D and cisplatin. The results show that the Egr1 promoter is induced by cisplatin and that this induction is mediated in part through the CArG elements. These studies also demonstrate an enhanced antitumor response without an increase in toxicity following treatment with Ad.Egr.TNF.11D and cisplatin, compared with either agent alone. Chemo-inducible cancer gene therapy thus provides a means to control transgene expression while enhancing the effectiveness of commonly used chemotherapeutic agents.

Tumor production of angiostatin is enhanced after exposure to TNF-alpha

Infection of tumors with an adenoviral vector expressing a chimeric gene composed of the CArG elements of the Egr-1 promoter and a cDNA encoding TNF-alpha (Ad.Egr-TNF) has previously been shown to result in the production of high intratumoral levels of TNF-alpha and thereby tumor regression. The antitumor effects of TNF-alpha were ascribed to vascular thrombosis. We and others, have reported that inhibition of tumor vessel thrombosis using anticoagulation therapy does not abrogate the antitumor effects after TNF-alpha treatment. To investigate the potential antiangiogenic effects of TNF-alpha, we studied the generation of angiostatin after intratumoral injection of Ad.Egr-TNF. We report an increase in plasma angiostatin levels both during and after treatment with Ad.Egr-TNF that parallel tumor regression. We also report that TNF-alpha enhances angiostatin production by inducing the activity of plasminogen activator and the release of MMP-9 by tumor cells. These studies support a model in which the antiangiogenic effects of TNF-alpha on the tumor microvasculature are mediated by generation of angiostatin.

Interferon-gamma and tumor necrosis factor-alpha induce synergistic cytolytic effects in ovarian cancer cell lines-roles of the TR60 and TR80 tumor necrosis factor receptors

OBJECTIVE

Utilizing ovarian cancer cell lines, we examined the effect of IFN-gamma on each type of TNF receptor. Additionally, we sought to determine the effect of receptor modulation on TNF-alpha-mediated cytolysis.

METHODS

Ovarian cancer cell lines Caov-3, A2780, and SK-OV-3 were employed. The number of TNF receptors was determined by a TNF-alpha binding assay utilizing 125I-labeled TNF-alpha. Monoclonal antibodies specific for the 55- to 60-kDa (TR60) and the 75- to 80-kDa (TR80) TNF receptors were used to determine the relative density of each receptor type. Northern blot analyses were performed employing cDNA probes for the TR60 and TR80 mRNAs. To elucidate which receptor(s) was responsible for mediating the signal for cytolysis, 24-h MTT cytolytic assays were performed in the presence of receptor-specific monoclonal antibodies.

RESULTS

IFN-gamma treatment resulted in an increase in TNF receptors in the cell lines A2780 and Caov-3 (P < 0.001), but not SK-OV-3. Northern blot analyses suggested distinct regulatory mechanisms for the two receptors. In Caov-3 and SK-OV-3 cells a synergistic increase in TNF-alpha-mediated cytolysis was seen when cells were pretreated with IFN-gamma. In both cell lines, pretreatment with IFN-gamma markedly enhanced the ability of the TR60 receptor to mediate cell lysis. Conversely, under similar treatment conditions, the TR80 receptor did not appear capable of generating a cytolytic signal.

CONCLUSIONS

TNF receptor modulation by IFN-gamma appears to be unique to individual cell lines. The TR60 TNF receptor plays a central role in the synergistic cytolytic effects of IFN-gamma and TNF-alpha. Sequential therapy with IFN-gamma and TNF-alpha and specific TNF receptor activation may provide novel translational strategies for the use of cytokines in the treatment of ovarian cancer.

Dipyridamole combined with tumor necrosis factor-alpha enhances inhibition of proliferation in human tumor cell lines

In the search for cytokines whose antiproliferative action could be enhanced by combination with dipyridamole, 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d]pyrim idine, the combination of tumor necrosis factor-alpha (TNF-alpha) with this agent was evaluated in various human tumor cell lines. Inhibition of the proliferation of human melanoma cell lines MM-1CB and HMV-1 by TNF-alpha (1-10(2) U/ml) was enhanced in culture dishes by combination treatment with dipyridamole (0.1-10 microM). The enhancement effect was also detected in other tumor cell lines: T98 (glioma), SCC-1CB (squamous cell carcinoma), HAC-2 (ovarian clear-cell carcinoma), HLE (hepatoma), HEC-1 (endometrial adenocarcinoma) and HOC-21 (ovarian serous cystadenocarcinoma). The incorporation of [14C]amino acids and [3H]uridine into acid-insoluble cell materials in the combination-treated cells was not significantly different from that in cells treated with TNF-alpha or dipyridamole. However, the incorporation of [3H]thymidine was specifically inhibited in all cell lines examined after more than 12 h of the TNF-alpha and dipyridamole combination treatment, although neither agent alone inhibited this incorporation. On the other hand, the growth of tumors induced by the injection of MM-1CB and HMV-1 cells into nude mice was more markedly inhibited by the subcutaneous administration of TNF-alpha in combination with orally administered dipyridamole than by either agent alone. The results presented suggested that dipyridamole is beneficial in assuring the effectiveness of anti-cancer cytokine therapy.

Activation of the anti-tumor effector cells by Radix bupleuri

Radix bupleuri, the root of Bupleuri spp., Chinese medicinal herbs used for the treatment of influenza, malaria and menstrual disorders, were extracted with hot water and separated into five different fractions (RB, RBI, RBII, RBIII and RBIV) by stepwise alcohol precipitation. One of these fractions, RBI, was then fractionated into RBIa and RBIb by gel filtration using G-100 Sephadex. These two fractions were further purified into RBIai, RBIaii and RBIbi, RBIbii fractions respectively by ion-exchange chromatography using DEAE-Sephadex. Each of these fractions is a heteropolymer consisting mainly of carbohydrate and varying proportions of protein and uronic acid. RBIaii was found to show strong anti-tumor activities in sarcoma-bearing mice. Mechanistic studies showed that RBIaii exhibited a potent activating effect on the cytotoxic activity of macrophages, NK and LAK cells against tumor cells. In addition, RBIaii could increase the number of tumor infiltrating lymphocytes (TILs) in the tumor site of WEHI-164-bearing mice. Furthermore, RBIaii could induce the release of interferon-gamma by lymphocytes in vitro.

Systemic and hemodynamic effects of recombinant tumor necrosis factor alpha in isolation perfusion of the limbs

OBJECTIVE

To describe the systemic effects of high-dose recombinant tumor necrosis factor alpha (rTNF-alpha), recombinant interferon gamma (rIFN-gamma), and melphalan administered through hyperthermic isolation perfusion of the limbs (IPL) in patients with melanoma and malignant soft-tissue tumors.

DESIGN

The clinical, hemodynamic, and biologic parameters were recorded after IPL during the postoperative period.

SETTING

Surgical intensive care service of a 1,000-bed tertiary university medical center.

PATIENTS

Nineteen patients referred to a pluridisciplinary Center for Oncology after relapse of regionally advanced melanoma or soft-tissues tumors, included in a phase 2 therapeutic study.

RESULTS

Major systemic and hemodynamic changes were observed after IPL in all patients. Ninety-four percent (17/18) of the evaluable patients presented a shock unresponsive to fluid challenge, requiring the continuous perfusion of vasopressors, inotropic agents, or both. Analysis of hemodynamic data showed two distinctive patterns: a pure distributive shock in nine patients requiring norepinephrine, and a mixed distributive and cardiogenic shock in eight patients requiring vasopressor and inotropic agents. The oxygen parameters were characterized by an increase in both the delivery and the uptake of oxygen, with a prolonged reduced oxygen extraction ratio for most patients. The other observed effects were as follows: transient bilateral or mixed pulmonary infiltrates in all patients; some hematologic disturbances in 83% of patients; infection requiring a modification of the antibiotic prophylaxis in 61% of patients; and some liver toxic reactions in 50% of patients. Very high systemic TNF-alpha serum bioactivity was found in 12 patients for whom serum samples were available, indicating an early and important rTNF-alpha leakage from the IPL. No correlations could be found between the levels of TNF-alpha and the observed systemic effects. Despite the severity of the hemodynamic disturbance, no patient died.

CONCLUSION

Major systemic effects, consisting mainly in cardiovascular, respiratory, and hematologic disturbances, were observed in patients after IPL with high-dose of rTNF-alpha. The likely explanation for these observations is an early rTNF-alpha leakage related to inadequate IPL technique. These data show that the iatrogenic administration of high circulating TNF levels lead to a "septic shock-like" syndrome without resulting in lethal organ dysfunction.

Hemopoietic growth and inhibitory factors in treatment of malignancies. A review

The clinical use of cytokines is still expanding as the knowledge of beneficial effects as adjunct to cancer treatment is increasing. G-CSF and GM-CSF stimulates hemopoietic recovery after myelosuppressive chemotherapy and enhances engraftment after bone marrow transplantation. New cytokines as IL-1, IL-3, IL-4 and IL-6, are studied in clinical trials and combinations of these with stem cell factor seem promising in ex vivo expansion of stem cells. GM-CSF also have antitumor effects. The most recently discovered hemopoietic growth factor is thrombopoietin, from which probably especially patients with leukemia will benefit.

Rationale for using TNF alpha and chemotherapy in regional therapy of melanoma

Recombinant tumor necrosis factor-alpha (rTNF alpha) has potent antitumor activity in experimental studies on human tumor xenografts. However, in humans, the administration of rTNF alpha is hampered by severe systemic side-effects. The maximum tolerated dose ranges from 350 to 500 mg/m2, which is at least 10-fold less than the efficient dose in animals. Isolation perfusion of the limbs (ILP) allows the delivery of high dose rTNF alpha in a closed system with acceptable side-effects. A protocol with triple-drug regimen was based on the reported synergism of rTNF alpha with chemotherapy, with interferon-gamma, and with hyperthermia. In melanoma-in-transit metastases (stage IIIA or AB) we obtained a 91% complete response, compared with 52% after ILP with melphalan alone. Release of nanograms levels of TNF alpha in the systemic circulation was evident but control of this leakage and appropriate intensive care resulted in acceptable toxicity. Angiographic, immunohistological, and immunological studies suggest that the efficacy of this protocol is due to a dual targeting: rTNF alpha activates and electively lyses the tumor endothelial cells while melphalan is mainly cytotoxic to the tumor cells. ILP with rTNF alpha appears to be a useful model for studying the biochemotherapy of cancer in man.

The immunostimulating activities of anti-tumor polysaccharides from Pseudostellaria heterophylla

We have previously shown that a mitogenic fraction (PH-I) separated from Pseudostellaria heterophylla exhibits both immunomodulatory and anti-tumor activities. In the present study, PH-I was further purified by gel filtration chromatography and the resulting three fractions (PH-I A, PH-I B and PH-I C) were assessed for their anti-tumor activity in vivo. It was found that fraction PH-I C from P. heterophylla could markedly suppress the growth of EAT cells in vivo. Mechanistic studies have shown that i.p. injection of PH-I C into mice could enhance the phagocytic activity of thioglycollate-elicited peritoneal macrophages. Moreover, PH-I C showed a potent activating effect on the cytotoxic activity of natural killer (NK) cells and alloreactive cytotoxic T cells (Tc) as well as increased the MurIL-2-induced lymphokine activated killer cell (LAK) activity in vitro. In addition, PH-I C could increase the number of tumor infiltrating lymphocytes (TILs) in the tumor site of WEHI-164-bearing mice. Finally, i.v. injection of PH-I C significantly elevated the levels of IFN-gamma and IL-4 in sera of EAT-bearing mice.

Etiologies, consequences, and treatment of iron overload

From a global perspective, severe systemic iron overload occurs predominantly in individuals affected by geographically specific genetic mutations that permit the daily absorption from the diet of more iron than is physiologically needed. Two main types of hereditary iron overload are well recognized: (1) HLA-linked hemochromatosis in populations derived from Europe and (2) iron overload complicating thalassaemia major and intermedia syndromes in Southeast Asia, the Middle East, and the Mediterranean. Another very common form of iron overload occurs in Africa and is clearly related to high dietary iron content; recent evidence suggests that a genetic predisposition may also contribute to the pathogenesis. Patients with iron overload may develop multiorgan system toxicity; aggressive therapy with phlebotomy or iron chelation to remove excess iron from the body prevents organ damage and prolongs life.

Coley's toxins, tumor necrosis factor and cancer research: a historical perspective

As far back as the 1700s, it was recorded that certain infectious disease processes could exert a beneficial therapeutic effect upon malignancy. Most prominent among the numerous deliberate efforts made to take advantage of these observations was that of a pioneering New York surgeon, William B. Coley, active career 1891-1936. Using a bacterial vaccine to treat primarily inoperable sarcoma. Coley accomplished a cure rate of better than 10%. This review examines the history of these efforts and presents a discussion of their corresponding relevance to present day immunotherapy.

Cytokine combinations in immunotherapy for solid tumors: a review

The use of cytokines alone or in combination with other cytokines or cytotoxic drugs has had a profound effect upon widely metastatic disease in many cases. However, despite the encouraging results in early trials, there is much room for improvement. Few responses to these combinations are complete, and toxicity has in some cases been quite severe. Changes in dose, route, or schedule of administration of the drugs, or the development of cytokine analogs may lead to more efficacious and less toxic regimens. In addition, new cytokines such as interleukin(IL)-7 and IL-12 are currently under investigation for potential use in future immunotherapy trials. These prospects and the use of cytokine combinations are promising advances in the treatment of human cancer.

Tumor necrosis factor activities and cancer therapy--a perspective

Tumor necrosis factor (TNF) is a multifunctional cytokine which has excited and fascinated numerous investigators and commercial entities due to its promise as a therapeutic agent against cancer and as a target for drugs treating septic shock. TNF is a protein having cytotoxic, cytostatic, immunomodulatory as well as several other activities and is also involved in septic shock. This review covers the structure of TNF and its receptors, various in vitro activities and in vivo activities based on studies in animal model systems. The role of TNF as an anticancer therapeutic agent, based on various phase I and phase II clinical studies, has also been considered. The review concludes with several considerations for increasing the therapeutic utility of TNF in terms of targeting, toxicity and half-life.

The cytokine network in the critically ill

There is increasing experimental and clinical evidence that a number of cytokines play a major role in the response to injury and infection and in the development of organ damage in critically ill patients. Tumour necrosis factor (TNF) is now proposed to be a key mediator of organ injury during sepsis. It is elevated early in the course of septic shock and high levels correlate with unfavourable outcome. In animals it can produce the effects of endotoxin. The prophylactic administration of anti-TNF antisera protects mice and rabbits from lethal effects of lipopolysaccharide. Interleukin-1 (IL-1) is an endogenous pyrogen which induces leukocytosis and muscle catabolism. It causes hypotension and tachycardia by reducing smooth muscle contractility. IL-1 receptor blockers have been shown to diminish mortality in experimental endotoxic shock. Interleukin-6 (IL-6) is a pyrogen and lymphocyte activator. It is the major stimulus to acute phase protein production by the liver. A recently described neutrophil-activating peptide (Interleukin-8; IL-8) may be involved in the pathogenesis of ARDS. High blood levels of IL-8 have been found in patients with septic shock. Platelet-derived growth factor (PDGF) has been shown to stimulate TNF production, leukocyte chemotaxis and pulmonary vasoconstriction in response to endotoxin. Other cytokines and growth factors have not yet been studied in critical illness. The cytokine network can be either protective or damaging. Its activation during critical illness triggers complex and still poorly understood interactions. A better comprehension of its role in protection from infection and in the pathogenesis of multiple organ failure may allow therapeutic manipulations aimed at minimising adverse effects while retaining immunological protection.

Serum cytokine profiles in experimental human malaria. Relationship to protection and disease course after challenge

Serum cytokine profiles were evaluated in immunized and nonimmunized human volunteers after challenge with infectious Plasmodium falciparum sporozoites. Three volunteers had been immunized with x-irradiated sporozoites and were fully protected from infection. Four nonimmune volunteers all developed symptomatic infection at which time they were treated. Sera from all volunteers were collected at approximately 20 time points during the 28-d challenge period; levels of IL-1 alpha, IL-1 beta, IL-2, IFN-gamma, tumor necrosis factor-alpha, IL-4, IL-6, granulocyte macrophage-colony-stimulating factor, and soluble CD4, CD8, and IL-2 receptor (sCD4, sCD8, and sIL-2R, respectively) were determined by ELISA. C-reactive protein (CRP) was assayed by radial immunodiffusion. Parasitemic subjects developed increases in CRP and IFN-gamma, with less marked increases in sIL-2R and sCD8; the other cytokines tested did not change. CRP increases were abrupt and occurred at the onset of fever (day 14 after challenge). IFN-gamma increases were also abrupt, preceding those of fever and CRP by one day. Increases in sIL-2R and sCD8 were more gradual. Increases in fever, CRP, IFN-gamma, and sCD8 were concordant in each volunteer. Early IL-6 increases were noted in the protected vaccinees. Thus, after challenge with virulent P. falciparum, unique systemic cytokine profiles were detectable both in immunized, nonparasitemic volunteers and in unvaccinated, parasitemic subjects. The contrasting cytokine profiles in the two groups may relate to mechanisms of protection and immunopathology in experimental human malaria.

Coley's toxins in perspective

Despite initial hopes, the efficacy of tumour necrosis factor in treating cancer patients has been disappointing. But a more careful selection of patients, and more appropriate treatment, might be fruitful.

Clinical and biologic effects of combination therapy with gamma-interferon and tumor necrosis factor

Tumor necrosis factor (TNF) and gamma-interferon (gamma-IFN) are cytokines with synergistic biologic and antiproliferative effects in vitro and in mouse models. The biologic effects of the combination of TNF and gamma-IFN, however, have not been studied well in humans. A Phase I trial was conducted of TNF and gamma-IFN therapy in 24 patients with advanced malignancies to determine the tolerability of the combination and the biologic effects of TNF and gamma-IFN in vivo. Both TNF and gamma-IFN were administered as 30-minute intravenous infusions three times per week. Doses of TNF ranged from 25 to 100 micrograms/m2; all patients received 100 micrograms/m2 of gamma-IFN. Dose-limiting toxicity consisted primarily of orthostatic hypotension and constitutional symptoms. The maximum tolerated dose level (MTDL) of 50 micrograms/m2 of TNF and 100 micrograms/m2 of IFN-gamma was less than the maximum tolerated dose (MTD) observed in previous Phase I trials of gamma-IFN and TNF alone. Biologic responses were studied in seven patients treated at the MTDL. Serum interleukin-2 receptor levels and neopterin secretion were enhanced significantly 24 hours after therapy (P = 0.002); enhancement of monocyte Fc receptor levels had borderline statistical significance (P = 0.07). With the exception of the mean fluorescent intensity on monocytes positive for histocompatibility antigen HLA-DR (P = 0.03), HLA Class I and II cell surface protein expression was not increased. The combination significantly enhanced indoleamine dioxygenase activity and serum beta 2-microglobulin expression (P less than 0.04) but not 2',5'-oligoadenylate synthetase activity, bactericidal function, or chemiluminescence. These results were compared retrospectively with those observed in previous Phase I trials of gamma-IFN and TNF alone. The combination of TNF and gamma-IFN significantly increased urinary kynurenine levels more than either TNF alone or gamma-IFN alone. Given the limitations inherent in any retrospective analysis, however, the enhancement in the other biologic parameters measured at the MTDL during this trial did not differ significantly from the changes observed at the MTD of either TNF or gamma-IFN alone. It was concluded that the combination of TNF and gamma-IFN, when administered at the MTDL of the combination, does not offer any enhancement in biologic responses over either agent alone.

Current status of interleukin-2 therapy in cancer

In vitro studies and animal experiments showed the existence of a physiological immune response against tumors. Interleukin-2 was the first immunological agent which demonstrated an anti-tumor effect by activating immune effectors. In vitro IL2 may generate Lymphokine Activated Killer (LAK) cells from peripheral blood lymphocytes or Tumor Infiltrating Lymphocytes (TIL) expanded from tumor. In melanoma and renal cell carcinoma, IL2 alone or associated with LAK cells or TIL, mediated clinical responses. However, their clinical efficacy was associated with some toxicity related to a capillary leak syndrome. This implies an improvement in the selection of patients and in the understanding of IL2 action. Future directions in immunotherapy included combination IL2 with other cytokines or monoclonal antibodies or chemotherapy. Lymphokine gene therapy is designed to introduce IL2 or other cytokine genes into tumor infiltrating lymphocytes or directly into tumors to reduce systemic toxicity and to achieve high local cytokine concentration. Animal models and the first human trials make this approach promising.

Tumor necrosis factor alpha modifies resistance to interferon alpha in vivo: first clinical data

Patients with Philadelphia-positive chronic-phase chronic myelogenous leukemia (CML) resistant to interferon (IFN) alpha were treated in a phase I/II study with recombinant human tumor necrosis factor alpha to overcome IFN alpha resistance. Doses of 40, 80, 120 or 160 micrograms/m2 TNF alpha were given as 2-h infusions on 5 consecutive days every 3 weeks. IFN alpha (4 x 10(6) IU/m2 s.c., daily) treatment was continued. Six patients were treated, completing 1-24 (median, 12) treatment cycles. Five of the six patients achieved partial hematological remission, while the remaining patient had to stop treatment because of WHO grade 4 thrombocytopenia following the first TNF alpha cycle. No complete hematologic remission or cytogenetic improvement was seen. Side-effects were similar to those described for both substances alone. Maximum tolerable TNF doses usually varied between 80 micrograms/m2 and 160 micrograms/m2. To examine possible pathways of TNF activity in these patients, interferon receptor status and (2'-5')-oligoadenylate synthetase levels were examined in peripheral blood mononuclear cells. Both parameters remained unchanged during TNF alpha treatment. These preliminary data point to significant clinical efficacy of additionally applied TNF alpha in IFN alpha-resistant CML patients.

Effects of interferons and other cytokines on tumors in animals: a review

The term cytokine describes a group of protein cell regulators involved in the control of cell growth and differentiation in embryogenesis, immunity and inflammation. They are of low molecular weight, are produced locally, and act in an autocrine or paracrine manner. In the past decade their use as cancer therapy has become a reality. Thirty years ago mice were treated with the antiviral protein interferon (IFN) which not only produced a reduction in the incidence of virus-induced tumors but also slowed the development of transplantable tumors. This was one of the first indications that cytokines can be negative regulators of cell growth. Here we outline current knowledge of the actions of IFNs and other cytokines in animal models, and draw parallels with clinical trials to illustrate the invaluable nature of this preclinical and mechanistic work.

A phase II combination trial with recombinant human tumor necrosis factor and gamma interferon in patients with colorectal cancer

Recombinant human tumor necrosis factor (TNF) is a cytotoxic monokine with immunomodulatory functions. Gamma interferon (g-IFN) synergizes with TNF in many ways. We therefore conducted a Phase I/II combination trial with TNF and g-IFN at an immunomodulatory dose level in 16 patients with colorectal cancer. TNF (50 micrograms/m2 in a 30 min infusion) and g-IFN (100 micrograms in subcutaneous injections) were administered daily Monday through Friday for 4 weeks. Two cases of major toxicity, one acute renal failure and one case of severe thrombocytopenia, led to discontinuation of study medication in these patients. Toxicities in remaining patients were manageable with conservative treatment. Changes in laboratory values included leukopenia, anemia and thrombocytopenia. Alterations in lipid metabolism and changes in serum levels of acute phase proteins were observed. Increase in both total lymphocytes and a Leu 11 positive subpopulation, as well as an induction of measurable interleukin 2 serum levels in a subgroup of patients, were noted. Response results of 14 evaluable patients were one patient with a mixed response, 4 with stable disease and 9 with disease progression. Median survival was 23.5 weeks with only one patient alive after 71 weeks. Therefore the drug combination of TNF/g-IFN in the chosen regimen cannot be recommended for the treatment of patients with colorectal cancer.

Inhibition of protein synthesis enhances the lytic effects of tumor necrosis factor alpha and interferon gamma in cell lines derived from gynecological malignancies

Few clinical responses have occurred in preliminary studies using the cytokines tumor necrosis factor alpha (TNF alpha) or interferon gamma (IFN gamma) in cancer patients. This may be related to the observation that many malignant cell lines are resistant to lysis by these cytokines in vitro. Resistance to lysis by TNF alpha or IFN gamma in many cells is controlled by a protein-synthesis-dependent mechanism, such that when protein synthesis is inhibited cells become sensitive to lysis by these cytokines. Because there is some evidence that TNF alpha and IFN gamma act through different lytic mechanisms and are opposed by different resistance mechanisms, we treated a panel of eight cell lines, five derived from human cervical carcinomas (ME-180, MS751, SiHa, HT-3, and C-33A) and three derived from ovarian carcinomas (Caov-3, SK-OV-3, and NIH: OVCAR-3) with both TNF alpha and IFN gamma to determine whether such combination treatment might maximize in vitro cell lysis. Our results showed that pretreatment with IFN gamma followed by exposure to TNF alpha in the presence of protein synthesis inhibitors increased lysis of seven of the eight cell lines above that seen with either TNF alpha or IFN gamma and inhibitors of protein synthesis. Only the cell line C-33A was resistant to lysis by TNF alpha and IFN gamma, when exposed to these agents both alone and in combination with protein synthesis inhibitors. Clinically, combining the cytokines TNF alpha and IFN gamma with protein synthesis inhibitors may maximize the in vivo lytic effects of these cytokines.

Production of tumor necrosis factor alpha and interferon gamma in interleukin-2-treated melanoma patients: correlation with clinical toxicity

Interleukin-2 (IL-2)-based immunotherapy regimens are accompanied by dose-limiting toxicity consisting of fever, tachycardia, chills and capillary leak syndrome. We hypothesized that the toxicity was caused by the induction and release of endogenous cytokines such as tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma). We measured the serum levels of TNF alpha and IFN gamma in IL-2-treated melanoma patients and attempted a correlation with clinical toxicity. A total of 23 patients received either 6 x 10(6) IU or 12 x 10(6) IU Cetus IL-2/m2 by i.v. bolus daily for 5 consecutive days on weeks 1, 3 and 5. Serum TNF alpha and IFN gamma levels were measured by enzyme-linked immunosorbent assay. Clinical toxicity was scored each day by objective measurements of hypotension, tachycardia, fever and chills/rigors. Clinical toxicity and IFN gamma levels correlated nicely, peaking on the 5th day of each treatment cycle. The kinetics and magnitude of TNF alpha production, however, were not predictable and did not correlate with either IFN gamma or toxicity. Some patients had modest increases in TNF alpha production while others had markedly increased levels during the second and third treatment weeks. Remarkably, these high levels persisted during nontreatment weeks and after completion of therapy. This clinical study demonstrates novel kinetics for immunoreactive TNF alpha in IL-2 cancer patients, which do not correlate well with toxicity.

Proliferative and antiproliferative effects of interferon-gamma and tumor necrosis factor-alpha on cell lines derived from cervical and ovarian malignancies

Four human cell lines derived from cervical carcinomas (ME-180, SiHa, HT-3, and MS751) and three human cell lines derived from ovarian carcinomas (SK-OV-3, Caov-3, and NIH:OVCAR-3) were analyzed in vitro to determine the effect of recombinant interferon-gamma and recombinant human tumor necrosis factor-alpha on cell growth and survival. The effects of interferon-gamma, tumor necrosis factor-alpha, and both interferon-gamma and tumor necrosis factor-alpha on cell growth were measured after 24 and 72 hours of incubation by the incorporation of chromium 51. The results of this analysis showed that all seven cell lines were resistant to the antiproliferative action of tumor necrosis factor-alpha, that the growth of most cell lines was inhibited by interferon-gamma by 72 hours of incubation, and that after 72 hours of incubation all cell lines demonstrated a synergistic antiproliferative response to the combination of interferon-gamma and tumor necrosis factor-alpha. However, the effects of these cytokines on cell growth were found to differ among cell lines and varied with the concentration and the duration of incubation. The growth of one cell line (Caov-3) was stimulated by both tumor necrosis factor-alpha and interferon-gamma. These results suggest that the clinical effects of these cytokines on the growth of gynecologic cancers may be more complex than previously supposed.

Biological response modifiers in the management of patients with breast cancer

Despite impressive progress in understanding the biology of breast cancer, mechanisms of host defense, and the pathophysiology of the metastatic process, this burgeoning fact bank has made little impact on the management of patients with breast cancer. There are many interesting ideas for improved diagnosis and therapy in various stages of development, but few have actually translated into improved survival of patients with breast cancer. Potentially useful biological agents include cytokines, monoclonal antibodies, immunotoxins, vaccines, and adoptive cellular therapies. Therapies targetting growth factor receptors and the cellular machinery required for metastasis may become useful, especially when used in combination with other cytotoxic agents. Colony-stimulating factors may allow a test of the hypothesis that augmented dose-intensity of cytotoxic chemotherapy will cure more patients. Though we are not yet sure precisely how to use all of these new tools, there can be little doubt that their application will make a significant impact on the management of patients with breast cancer and other malignancies in the next decade.

A phase II trial of recombinant tumor necrosis factor in patients with advanced colorectal carcinoma

Sixteen previously treated (with only one prior regimen) patients with histologically proven metastatic or locally recurrent colorectal carcinoma were treated with recombinant tumor necrosis factor (rTNF) administered by 30-minute i.v. infusions twice daily for 5 consecutive days every other week for 8 weeks. Patients received 100 micrograms/m2 twice daily on day 1 of cycle 1 with escalation to 150 micrograms/m2 twice daily thereafter. Patients were concomitantly treated with indomethacin 25 mg every 6 hours and acetaminophen 650 mg every 4 hours to obviate fever and chills. Toxicities included: nausea/vomiting (69%), headache (25%), chills (69%), pain at tumor sites (63%), hypotension (31%), and hypertension (38%). Hematologic toxicity included leukopenia less than 2000 cells/mm3 (38%) and thrombocytopenia less than 100,000 cells/mm3 (13%). Liver function abnormalities occurred independently of the site or extent of metastatic disease and inconsistently in each treatment cycle. Four patients developed bilirubinemia greater than 2.5 x baseline values (range, 2.5 to 10.3 U/L); five patients had greater than 2.5 x elevations in alkaline phosphatase (range, 624 to 1663 U/L). Two patients developed retinal vein thrombosis in the absence of hemostatic abnormalities. In both instances, this complication occurred several weeks after completion of therapy. No objective responses were noted in 14 evaluable patients (95% confidence interval: 0 to 0.23). Three patients had stable disease for a median duration of 4.5 months. In conclusion, i.v. rTNF at this dose and schedule has no demonstrable antitumor efficacy. Twice-daily i.v. administration of this agent is associated with more hepatotoxicity than previously reported in trials using subcutaneous or once daily i.v. administration. Retinal vein thrombosis may be a late complication of i.v. rTNF at this dose and schedule.

Clinical use of biologic response modifiers in cancer treatment: an overview. Part I. The interferons

Interferons are proteins with antiviral, antiproliferative, and immune-regulating activity. They are classified as alfa, beta, or gamma on the basis of antigenicity and biologic properties. Alfa interferons as single-agent therapy produce clinical improvement in approximately 90 percent of patients with hairy-cell leukemia, and up to 70 percent of patients with chronic myelogenous leukemia (CML) in early-stage disease. Prolonged suppression or elimination of the leukemic cell clone by interferon may ultimately increase survival of patients with CML. Interferon is not effective single-agent therapy for multiple myeloma, but improves response rate when combined with conventional agents. AIDS-associated Kaposi's sarcoma demonstrates a 40 percent objective response rate to interferon, with less risk of immune system suppression than conventional cytotoxics. Other applications of alfa interferon include malignant melanoma and renal cell carcinoma. Beta interferon is similar to the alfa subtype and may have utility in treatment of brain tumors. Gamma interferon is an important immune regulator with qualitative and quantitative differences in its efficacy and toxicity when compared with alfa interferon.