Pharmacodynamics of recombinant IFN-beta during long-term treatment of malignant melanoma

Allogeneic stem cells engineered to release interferon β and scFv-PD1 target glioblastoma and alter the tumor microenvironment

Highly malignant brain tumors, glioblastomas (GBM), are immunosuppressive, thereby limiting current promising immunotherapeutic approaches. In this study, we created interferon receptor 1 knockout allogeneic mesenchymal stem cells (MSC) to secrete dual-function pro-apoptotic and immunomodulatory interferon (IFN) β (MSCKO-IFNβ) using a single lentiviral vector CRISPR/Cas9 system. We show that MSCKO-IFNβ induces apoptosis in GBM cells and upregulates the cell surface expression of programmed death ligand-1 in tumor cells. Next, we engineered MSCKO to release a secretable single-chain variable fragment (scFv) to block programmed death (PD)-1 and show the ability of MSCKO-scFv-PD1 to enhance T-cell activation and T-cell-mediated tumor cell killing. To simultaneously express both immune modulators, we engineered MSCKO-IFNβ to co-express scFv-PD1 (MSCKO-IFNβ-scFv-PD1) and show the expression of both IFNβ and scFv-PD1 in vitro leads to T-cell activation and lowers the viability of tumor cells. Furthermore, to mimic the clinical scenario of GBM tumor resection and subsequent treatment, we show that synthetic extracellular matrix (sECM) encapsulated MSCKO-IFNβ-scFv-PD1 treatment of resected tumors results in the increase of CD4+ and CD8+ T cells, mature conventional dendritic cells type II and activation of microglia as compared to the control treatment group. Overall, these results reveal the ability of MSCKO-IFNβ-scFv-PD1 to shape the tumor microenvironment and enhance therapeutic outcomes in GBM.

Antitumor activity of pegylated human interferon β as monotherapy or in combination with immune checkpoint inhibitors via tumor growth inhibition and dendritic cell activation

Type I interferons (IFN), especially human IFN alpha (IFNα), have been utilized for antitumor therapy for decades. Human interferon beta (IFNβ) is rarely used for cancer treatment, despite advantages over IFNα in biological activities such as tumor growth inhibition and dendritic cell (DC) activation. The utilization of pegylated human IFNβ (PEG-IFNβ), as monotherapy or in combination with immune checkpoint inhibitors (ICIs) was evaluated in this study through in vivo efficacy studies in syngeneic mouse melanoma, non-small cell lung cancer (NSCLC), and colon adenocarcinoma (COAD) models resistant to immune checkpoint inhibitors (ICIs). In vitro comparative study of PEG-IFNβ and pegylated IFNα-2b was performed in terms of tumor growth inhibition against human melanoma, NSCLC and COAD cell lines and activation of human monocyte-derived DCs (MoDCs). Our data demonstrate that the in vivo antitumor effects of PEG-IFNβ are partially attributable to tumor growth-inhibitory effects and DC-activating activities, superior to pegylated IFNα-2b. Our findings suggest that utilizing PEG-IFNβ as an antitumor therapy can enhance the therapeutic effect of ICIs in ICI-resistant tumors by directly inhibiting tumor growth and induction of DC maturation.

Interferons in the Therapy of Severe Coronavirus Infections: A Critical Analysis and Recollection of a Forgotten Therapeutic Regimen with Interferon Beta

The pharmacological and immunological properties of interferons, especially those of interferon beta, and the corresponding treatment strategies are described, and the results of studies with different interferons in coronavirus infections are analysed. Furthermore, the data obtained with high-dosed native interferon beta in life-threatening acute viral diseases as well as the results of clinical pilot studies with high-dosed recombinant interferon beta-1a are provided because they serve as the rationale for the proposed therapeutic regimen to be applied in acute viral infections. This regimen differs from those approved for treatment of multiple sclerosis and consists of interferon beta-1a administered as a 24 hour intravenous infusion at a daily dose of up to 90 µg for 3-5 consecutive days. Since under this regimen transient severe side effects can occur, it is analysed which patients are suitable for this kind of treatment in general and if patients with severe coronavirus infections could also be treated accordingly.

Engineered stem cells targeting multiple cell surface receptors in tumors

Multiple stem cell types exhibit inherent tropism for cancer, and engineered stem cells have been used as therapeutic agents to specifically target cancer cells. Recently, stem cells have been engineered to target multiple surface receptors on tumor cells, as well as endothelial and immune cells in the tumor microenvironment. In this review, we discuss the rationales and strategies for developing multiple receptor-targeted stem cells, their mechanisms of action, and the promises and challenges they hold as cancer therapeutics.

Tumor Resection Recruits Effector T Cells and Boosts Therapeutic Efficacy of Encapsulated Stem Cells Expressing IFNβ in Glioblastomas

Purpose: Despite tumor resection being the first-line clinical care for glioblastoma (GBM) patients, nearly all preclinical immune therapy models intend to treat established GBM. Characterizing cytoreductive surgery-induced immune response combined with the administration of immune cytokines has the potential of offering a new treatment paradigm of immune therapy for GBMs.Experimental Design: We developed syngeneic orthotopic mouse GBM models of tumor resection and characterized the immune response of intact and resected tumors. We also created a highly secretable variant of immune cytokine IFNβ to enhance its release from engineered mouse mesenchymal stem cells (MSC-IFNβ) and assessed whether surgical resection of intracranial GBM tumor significantly enhanced the antitumor efficacy of targeted on-site delivery of encapsulated MSC-IFNβ.Results: We show that tumor debulking results in substantial reduction of myeloid-derived suppressor cells (MDSC) and simultaneous recruitment of CD4/CD8 T cells. This immune response significantly enhanced the antitumor efficacy of locally delivered encapsulated MSC-IFNβ via enhanced selective postsurgical infiltration of CD8 T cells and directly induced cell-cycle arrest in tumor cells, resulting in increased survival of mice. Utilizing encapsulated human MSC-IFNβ in resected orthotopic tumor xenografts of patient-derived GBM, we further show that IFNβ induces cell-cycle arrest followed by apoptosis, resulting in increased survival in immunocompromised mice despite their absence of an intact immune system.Conclusions: This study demonstrates the importance of syngeneic tumor resection models in developing cancer immunotherapies and emphasizes the translational potential of local delivery of immunotherapeutic agents in treating cancer. Clin Cancer Res; 23(22); 7047-58. ©2017 AACR.

Interferon-beta treatment for relapsing multiple sclerosis

BACKGROUND

Recombinant forms of IFN-beta were the first therapeutic intervention found to be effective at interfering with the course of multiple sclerosis (MS), a chronic and debilitating disease affecting the CNS in young adults.

OBJECTIVE/METHODS

To examine the application of IFN-beta to MS treatment by a review of relevant literature.

RESULTS

The different IFN-beta products available are similar in their clinical effects. However, the response to IFN-beta therapy is only partial and the most efficient individual-specific dose, route and frequency of administration are not elucidated fully. The mechanism of action of IFN-beta in MS is also not understood fully but its immunomodulatory effects are probably more important than its anti-proliferative and antiviral activities.

CONCLUSIONS

Although new therapeutic approaches are being sought to better treat MS, IFN-beta remains one of the most recognized and approved worldwide therapeutic options for this disease.

Growth inhibitory effects of IFN-beta on human liver cancer cells in vitro and in vivo

We investigated the effects of interferon-beta (IFN-beta) on the growth of human liver cancer cells. The effects of IFN-beta with or without 5-fluorouracil (5-FU) on the proliferation of 13 liver cancer cell lines were investigated in vitro. Chronologic change in IFN-alpha receptor 2 (IFNAR-2) expression was monitored in hepatocellular carcinoma (HCC) cells (HAK-1B) cultured with IFN-beta. After HAK-1B cells were transplanted into nude mice, various doses of IFN-beta were administered, and the tumor volume, weight, histology, tumor blood vessel, and angiogenesis factor expression were examined. IFN-beta inhibited the growth of 11 cell lines with apoptosis in a dose-dependent and time-dependent manner. With IFN-beta, IFNAR-2 expression in HAK-1B cells was significantly downregulated from 6 to 12 h. IFN-beta induced a dose-dependent decrease in tumor volume and weight and a significant increase of apoptosis in the tumor. Both basic fibroblast growth factor (bFGF) and blood vessel number in the tumor decreased only in mice receiving the lowest dose (1000 IU) of IFN-beta. IFN-beta with 10 muM of 5-FU frequently induced synergistic antiproliferative effects. IFN-beta with or without 5-FU induces strong antitumor effects in HCC cells, and we conclude that IFN-beta is useful for the prevention and treatment of HCC.

Phase 2 trial of the continuous IV administration of interferon-beta in patients with disseminated malignant melanoma

BACKGROUND

Interferons have been reported to significantly contribute to tumor suppression via both induction of p53 gene expression and inhibition of angiogenesis.

OBJECTIVE

The assessment of treatment toxicity and antitumoral effectiveness of continuous IV administration of interferon-beta based on an overall evaluation of laboratory, radiographic, and clinical parameters observed during the trial.

METHODS

The authors treated patients with advanced malignant melanoma with continuous IV infusions of 1 x 10(6) IU interferon-beta daily ( approximately 0.6 x 10(6) IU interferon-beta/m2 daily).

RESULTS

Continuous IV administration of interferon-beta had no significant effect on overall patient outcome. Interferon side effects were not a reason for treatment discontinuation in any of the patients observed during this trial.

CONCLUSIONS

Continuous IV interferon-beta had no significant effect on overall patient outcome in a group of patients with advanced malignant melanoma. To our knowledge, this is the first report on the continuous IV administration of interferon-beta in patients with advanced malignant melanoma.

Dynamics of interferon-beta modulated mRNA biomarkers in multiple sclerosis patients with anti-interferon-beta neutralizing antibodies

The objective of this study was to evaluate multiple interferon (IFN) specific mRNA biomarkers in multiple sclerosis (MS) patients with anti-IFN-beta neutralizing antibodies (NAB) using a pharmacodynamic study design. Thirty patients were enrolled. Blood samples were drawn at pre-treatment, 4-, 8-h time points following the intramuscular dose of IFN-beta-1a. Total RNA was obtained from peripheral blood cells, processed to cDNA and analyzed using quantitative real-time polymerase chain reaction. Pre-treatment serum samples were analyzed for anti-IFN-beta binding and neutralizing antibodies: 22 patients were NAB negative; equal numbers of the eight remaining patients were either NAB positive or had borderline NAB status. The results showed that early assessment (at 4 h after IFN-beta injection) of mRNAs for Stat-1, MxA, MxB and TRAIL was more sensitive than the later measurements. Furthermore, the NAB positive patients had strongly attenuated gene expression responses on all the mRNAs. Patients with borderline NAB had average responses that appear to be lower than NAB negative patients on several genes, notably Stat-1, TRAIL and beta2 microglobulin.

Combined 5-fluorouracil/systemic interferon-beta gene therapy results in long-term survival in mice with established colorectal liver metastases

Preclinical in vitro and in vivo studies have demonstrated synergistic interactions between 5-fluorouracil (5-FU) and type I and II IFNs against human colorectal cancer cells. Despite these activities, randomized human trials have failed to identify a clinical benefit for this combination treatment. These limited clinical results may be secondary to the short half-life of recombinant IFN protein and the increased systemic toxicities of 5-FU/IFN combinations. We have previously reported an adenoviral-mediated IFN-beta gene therapy strategy, which may circumvent the pitfalls of recombinant IFN therapy. However, a dose-dependent toxicity and acute inflammatory response to systemically administered adenovirus vectors may limit the clinical application of this therapy. The combination of adenoviral-mediated IFN-beta gene therapy and 5-FU resulted in tumor regression, apoptosis, and improved survival in an established liver metastases model. These therapeutic effects were observed at a significantly lower vector dose than we had previously reported and with limited toxicity. This approach may allow for an effective clinical application of this therapy and warrants additional investigation.

Beneficial effect of interferon-β 1b treatment in patients with relapsing–remitting multiple sclerosis is associated with an increase in serum levels of soluble HLA-I molecules during the first 3 months of therapy

It has recently become clear that interferon-beta (IFN-beta) treatment is effective in ameliorating relapsing-remitting multiple sclerosis (RRMS) through an as yet unidentified mechanism. As there is no recognisable biological indicator to predict responsiveness to IFN-beta treatment, we have investigated fluctuations in serum sHLA-I levels in MS patients undergoing IFN-beta 1b therapy. Serum sHLA-I concentrations measured by enzyme-linked immunosorbent assay (ELISA) were assessed at baseline and, longitudinally, over a period of 18 months after the start of treatment in 29 RRMS patients grouped as responders and nonresponders according to their clinical response to IFN-beta 1b therapy. Thirty-nine healthy volunteers served as controls. Serum sHLA-I concentrations were significantly higher (p<0.001) in pretreated RRMS patients than in healthy donors. In MS patients, changes in mean serum levels of sHLA-I from baseline showed a temporal pattern characterized by a strong increase in the first trimester of treatment, a return toward basal values in the following 6 months, a slight decline at 12th and 15th months and a further moderate increase at the 18th month. Mean serum sHLA-I levels were significantly more elevated in responders than in nonresponders at the first (p<0.02), second (p<0.01), and at third (p<0.02) months after the beginning of treatment and significantly lower (p<0.01) at the time of relapses in comparison to baseline values. Overall, these results seem to indicate that IFN-beta 1b can modulate fluctuations in serum sHLA-I levels and argue in favour of a potential role for serum levels of sHLA-I as a sensitive marker to monitor response to IFN-beta treatment in MS.

Interferons in enteroviral heart disease: modulation of cytokine expression and antiviral activity

Interferon (IFN)-beta has a more than 120-fold higher antiviral activity than the closely related IFN-alpha in human myocardial fibroblasts infected with the cardiotropic enterovirus coxsackievirus B3 (CVB3). CVB3 replication induces interleukin (IL)-6 and IL-8 expression in myocardial fibroblasts, and suppresses the expression of monocyte chemoattractant protein-1 (MCP-1). We investigated whether the higher antiviral activity of IFN-beta compared to IFN-alpha was a result of a suppression of IL-8 expression by IFN-beta since previous studies had indicated that IL-8 stimulates enterovirus replication. Human myocardial fibroblasts were treated with either IFN-alpha, IFN-beta or IFN-gamma (0, 10, 100, or 1,000 IU/ml) and the concentrations of IL-6, IL-8 and MCP-1 were measured in culture supernatants by immunoassays. Both IFN-beta and IFN-gamma reduced IL-6 and IL-8 expression significantly. In addition, neutralization of IL-8 in culture supernatants of myocardial fibroblasts using a monoclonal antibody demonstrated a significant reduction of CVB3 titers. Antiproliferative effects of all three IFNs were very low (<30% with 1,000 IU/ml), indicating that the suppression IL-6 and IL-8 was not related to cytotoxicity. MCP-1 expression was increased only by high concentrations of IFN-gamma (1,000 IU/ml). By contrast, IFN-alpha had no significant effect on IL-6, IL-8 and MCP-1 expression. In conclusion, suppression of IL-8 expression is an "immuno-modulating" feature of IFN-beta in human myocardial fibroblasts, which is similar to the activity of IFN-gamma. This feature of IFN-beta contributes to its high antiviral activity against CVB3 and may be useful in the treatment of enteroviral heart disease.

Genomic effects of IFN-beta in multiple sclerosis patients

The purpose of this report was to characterize the dynamics of the gene expression cascades induced by an IFN-beta-1a treatment regimen in multiple sclerosis patients and to examine the molecular mechanisms potentially capable of causing heterogeneity in response to therapy. In this open-label pharmacodynamic study design, peripheral blood was obtained from eight relapsing-remitting multiple sclerosis patients just before and at 1, 2, 4, 8, 24, 48, 120, and 168 h after i.m. injection of 30 micro g of IFN-beta-1a. The total RNA was isolated from monocyte-depleted PBL and analyzed using cDNA microarrays containing probes for >4000 known genes. IFN-beta-1a treatment resulted in selective, time-dependent effects on multiple genes. The mRNAs for genes implicated in the anti-viral response, e.g., double-stranded RNA-dependent protein kinase, myxovirus resistance proteins 1 and 2, and guanylate binding proteins 1 and 2 were rapidly induced within 1-4 h of IFN-beta treatment. The mRNAs for several genes involved in IFN-beta signaling, such as IFN-alpha/beta receptor-2 and Stat1, were also increased. The mRNAs for lymphocyte activation markers, such as IFN-induced transmembrane protein 1 (9-27), IFN-induced transmembrane protein 2 (1-8D), beta(2)-microglobulin, and CD69, were also increased in a time-dependent manner. The findings demonstrate that IFN-beta treatment induces specific and time-dependent changes in multiple mRNAs in lymphocytes of multiple sclerosis patients that could provide a framework for rapid monitoring of the response to therapy.

Pharmacological methods to overcome IFN-beta antibody formation in the treatment of multiple sclerosis

Diminished efficacy in terms of clinical relapses and lesion load on magnetic resonance images for patients developing neutralising antibodies (NAbs) to recombinant IFN-beta may be found in multiple sclerosis. NAbs become detectable over the first few years of therapy, disappearing during the treatment course in some patients and persisting longer in some others. Therefore, the administration of concomitant therapies to recombinant IFNbeta to prevent the formation of NAbs could be indicated mainly in the latter group of patients at the early stage of the treatment. Among those therapies, steroids meet the best criteria in terms of either safety or impact on the development of NAbs, at the present time.

Receptor-mediated pharmacokinetics and pharmacodynamics of interferon-beta1a in monkeys

A pharmacokinetic/pharmacodynamic (PK/PD) model was developed to simultaneously characterize interferon after i.v. and s.c. dosing at various dose levels. A sequential study in monkeys (n = 18) was conducted, where single doses of 1, 3, and 10 MIU/kg of recombinant-human interferon-beta (IFN-beta) 1a were given i.v. and then s.c. Plasma concentrations of IFN-beta were determined and biphasic neopterin concentrations were used as the pharmacodynamic (PD) endpoint. Multiple dosing also was evaluated by giving 1 MIU/kg s.c. doses once daily for 7 days (n = 3). The integrated model uses target-mediated drug disposition to describe drug elimination by receptor binding and internalization, and well characterizes the observed nonlinear pharmacokinetic (PK) profiles. The s.c. doses exhibited an absorption phase (Tmax = 3 h) and incomplete bioavailability (F = 0.3-0.7). An indirect response model for stimulation of neopterin triphosphate production by activated receptor complex followed by conversion to neopterin was used to jointly model the formation and loss of neopterin with a capacity factor Smax = 23.8. Greater relative neopterin response after s.c. dosing was accounted for by prolonged receptor activation relative to the SC50 value. Repeated daily s.c. dosing produced modestly elevated IFN-beta1a concentrations and neopterin concentrations that were lower than simulated from single-dose modeling. Although several mechanisms could be involved, these phenomena were simply remodeled as down-regulation of Smax and receptors. The PK/PD model for IFN-beta1a depicts receptor binding as a key feature controlling nonlinear elimination, nonstationary kinetics, and neopterin induction in a manner consistent with known processes controlling its disposition and pharmacological effects.

An IFN-beta-albumin fusion protein that displays improved pharmacokinetic and pharmacodynamic properties in nonhuman primates

The long half-life and stability of human serum albumin (HSA) make it an attractive candidate for fusion to short-lived therapeutic proteins. Albuferon (Human Genome Sciences [HGS], Inc., Rockville, MD) beta is a novel recombinant protein derived from a gene fusion of interferon-beta (IFN-beta ) and HSA. In vitro, Albuferon beta displays antiviral and antiproliferative activities and triggers the IFN-stimulated response element (ISRE) signal transduction pathway. Array analysis of 5694 independent genes in Daudi-treated cells revealed that Albuferon beta and IFN-beta induce the expression of an identical set of 30 genes, including 9 previously not identified. In rhesus monkeys administered a dose of 50 microg/kg intravenously (i.v.) or subcutaneously (s.c.) or 300 microg/kg s.c., Albuferon beta demonstrated favorable pharmacokinetic properties. Subcutaneous bioavailability was 87%, plasma clearance at 4.7-5.7 ml/h/kg was approximately 140-fold lower than that of IFN-beta, and the terminal half-life was 36-40 h compared with 8 h for IFN-beta. Importantly, Albuferon beta induced sustained increases in serum neopterin levels and 2',5' mRNA expression. At a molar dose equivalent to one-half the dose of IFN-beta, Albuferon beta elicited comparable neopterin responses and significantly higher 2',5'-OAS mRNA levels in rhesus monkeys. The enhanced in vivo pharmacologic properties of IFN-beta when fused to serum albumin suggest a clinical opportunity for improved IFN-beta therapy.

Receptor-mediated pharmacokinetic/pharmacodynamic model of interferon-beta 1a in humans

PURPOSE

An integrated receptor-based pharmacokinetic/pharmacodynamic (PK/PD) model of interferon-beta la (IFN-beta la) previously developed for monkeys was used to capture the time-course of drug and induced neopterin concentrations after intravenous (IV) and subcutaneous (SC) dosing in humans.

METHODS

Data were extracted from the literature by digitalization. Single-dose (3 IV doses and I SC dose) PK/PD profiles were simultaneously fitted using the basic model and the ADAPT II computer program. Additional submodels incorporating neutralizing antibody formation and negative feedback inhibition were applied to account for drug accumulation and lower than expected neopterin concentrations encountered after multiple-dosing (1 SC dose every 48 hs).

RESULTS

The basic model jointly-captured the nonlinear PK behavior of the drug and induced neopterin concentrations after all single doses. Slow and incomplete absorption (F = 0.33) of the SC dose resulted in prolonged drug concentrations reflective of flip-flop kinetics. Despite lower drug concentrations, SC dosing produced a similar neopterin profile as compared with the IV doses; however, with a longer time to peak effect and slightly higher neopterin concentrations at later time points. The PD component of the model represents a modified precursor-dependent indirect response model driven by the amount of internalized drug-receptor complex. The latter stimulated a 6-fold increase in the production of the neopterin precursor (Smax = 5.89). Drug accumulation and lower than expected neopterin concentrations after multiple dosing were also captured after the inclusion of the submodels.

CONCLUSIONS

The present integrated PK/PD model for IFN-beta 1a is mechanistic in nature with receptor-mediated disposition and dynamics and was successfully applied to human clinical data.

Successful palliation of stenosing anorectal melanoma by intratumoral injections with natural interferon-beta

Anorectal malignant melanoma is an uncommon tumour. Unlike for cutaneous melanoma, there are few guidelines for its optimal management. In particular, very few palliative treatment strategies have been described for patients with advanced disease. We report on an 80 year old patient with locally advanced anorectal melanoma nearly completely blocking the anal orifice and disseminated metastases. Complete regression of the primary tumour and partial remission of the metastases was achieved with intratumoral injections of natural interferon-beta and systemic administration of dacarbazine. The quality of life in this patient was improved markedly by providing relief from severe rectal pain and bleeding. We propose that conservative treatment strategies such as intratumoral injections with interferon-beta should be considered as a palliative treatment option for stenosing anorectal melanoma before an abdominoperineal resection is recommended.

Cytotoxicity of combinations of IFN-beta and chemotherapeutic drugs

Interferon-beta (IFN-beta) induces various antiproliferative activities. In solid tumor cells, IFN-beta inhibits cell cycle progression, which mainly occurs as S phase accumulation. The IFN-beta-induced cell cycle effect has been implicated in the antitumor effect of combinations of IFN-beta and chemotherapeutic drugs. In this report, we characterized the viability of various human tumor cells in vitro after combination treatment with IFN-beta protein and the chemotherapeutic drugs, cis-platinum (II) diamine dichloride (cisplatin), 5-fluorouracil (5-FU), paclitaxel (Taxol) and gemcitabine. IFN-beta could significantly potentiate the cytotoxicity of these chemotherapeutic drugs. The potentiating effect was observed after pretreatment of tumor cells with IFN-beta but did not require the constant presence of IFN-beta. The potentiating effect correlated with the sensitivity of the tumor cells to the IFN-beta-induced cytotoxicity. Furthermore, chemotherapeutic drugs also potentiated the cytotoxicity of IFN-beta. We conclude that the cell cycle effect per se did not determine the ability of IFN-beta to potentiate the cytotoxicity of chemotherapeutic drugs. We suggest that the combination of local IFN-beta gene therapy with chemotherapy could be an effective cancer treatment.

CD4+ T helper cell-independent antitumor response mediated by murine IFN-beta gene delivery in immunocompetent mice

Previously, we provided evidence that adenovirus-mediated interferon-beta (IFN-beta) gene therapy inhibits tumor formation and causes dramatic regression of established tumors in immunodeficient mice. We suggested that local IFN-beta gene therapy with adenoviral vectors could be an effective treatment for cancer. In this report, the actions of murine IFN-beta (MuIFN-beta) gene delivery on both subcutaneous and metastatic tumors were evaluated in syngeneic immunocompetent mice. We found that the antitumor response mediated by MuIFN-beta gene delivery relied on CD8(+) T cells but was completely independent of CD4(+) T cells. In fact, depletion of CD4(+) T cells appeared to enhance the effect on tumor inhibition and animal survival induced by adenovirus-MuIFN-beta gene delivery. Therefore, adenovirus-MuIFN-beta gene therapy can bypass CD4(+) T helper (Th) cells and activate an effective CD8(+) T cell-dependent antitumor immunity in immunocompetent mice. Furthermore, we found that depletion of macrophages but not natural killer (NK) cells suppressed the antitumor response induced by MuIFN-beta gene therapy. These data, together with our previous results, suggest that in the clinical setting, local adenovirus-mediated IFN-beta gene therapy may lead to an efficient and long-lasting eradication of tumors by a direct antitumor effect and via activation of the innate and the adoptive immune systems.

Primary malignant melanoma of the male urethra

We report a case of primary malignant melanoma of the male urethra in a patient whose penile shaft was successfully preserved, but who proceeded to acute renal failure (ARF) after interferon (IFN)-beta adjuvant immunotherapy. Primary malignant melanoma of the male urethra is rare and usually shows highly malignant potential. Therefore, urologists must often perform phallectomy, which impacts on the patient both sexually and mentally. A 64-year-old man presented at Saiseikai Sendai Hospital with asymptomatic gross hematuria and was diagnosed as distal urethral tumor. We predicted the highly malignant potential of this tumor from the urethroscopic finding and from urinary cytological examination. We did not select trans-urethral resection (TUR), but selected partial urethrectomy. This patient proceeded to ARF 1 month after natural IFN-beta treatment as an adjuvant immunotherapy. As IFN-beta rarely induces the delayed renal failure, urologists should be aware of renal dysfunction after IFN-beta therapy for the treatment of malignant melanoma.

Human and mouse IFN-beta gene therapy exhibits different anti-tumor mechanisms in mouse models

Previously, we suggested that local human interferon-beta (IFN-beta) gene therapy with replication-defective adenoviral vectors can be an effective cancer treatment. Clinical trials to treat cancers with adenovirus expressing the human IFN-beta gene (IFNB1) has been planned. As a continued effort to explore the mechanisms of action of human IFN-beta gene therapy that can occur in the clinical setting, we tested mouse IFN-beta gene therapy in human xenograft tumors in both ex vivo and in vivo models. Delivery of the mouse IFN-beta gene (Ifnb) caused tumor inhibition; this effect was dependent on the indirect anti-tumor activities of IFN-beta, notably a stimulation of natural killer cells. IFN-beta does not show cross-species activity in its anti-proliferative effect and mouse IFN-beta does not cause as significant an anti-proliferative effect on mouse tumor cells as human IFN-beta causes on human tumor cells. Therefore, we believe that mouse models using either human IFN-beta or mouse IFN-beta gene transfer do not capture all aspects of the action of adenovirus-mediated human IFN-beta gene therapy that may be present in the clinical setting. Due to its multiple mechanisms of action, human IFN-beta gene therapy may be effective in treating human cancers that are either sensitive or resistant to the direct anti-proliferative effect of IFN-beta.

Systemic IFN-beta gene therapy results in long-term survival in mice with established colorectal liver metastases

Most patients succumbing to colorectal cancer fail with liver-predominant metastases. To make a clinical impact in this disease, a systemic or whole-liver therapy may be required, whereas most cancer gene therapy approaches are limited in their ability to treat beyond local disease. As a preclinical model for cancer gene therapy, recombinant adenovirus containing the human IFN-beta (hIFN-beta) cDNA was delivered systemically in nude mouse xenograft models of human colorectal cancer liver metastases. The vector targeted hepatocytes that produced high levels of hIFN-beta in the liver, resulting in a profound apoptotic response in the tumors and significant tumor regression. hIFN-beta gene therapy not only resulted in improved survival and long-term cure in a micrometastatic model, but provided similar benefits in a clinically relevant gross disease model. A similar recombinant adenovirus containing the murine IFN-beta (mIFN-beta) cDNA also resulted in a therapeutic response and improved survival in syngeneic mouse models of colorectal cancer liver metastases. Depletion studies demonstrate a contribution of natural killer cells to this therapeutic response. The toxicity of an adenoviral vector expressing murine IFN-beta in a syngeneic model is also presented. These encouraging results warrant further investigation of the use of cancer gene therapy for targeting metastatic disease.

Pharmacokinetics and pharmacodynamics of IFN-beta 1a in healthy volunteers

The pharmacokinetics of recombinant human interferon-beta1a (IFN-beta1a) (Rebif, Ares-Serono, Geneva, Switzerland) were investigated in healthy volunteers following intravenous (i.v.) administration of increasing single doses of the drug (22 microg/6 million international units [MIU], 44 microg/12 MIU, and 66 microg/18 MIU); i.v., intramuscular (i.m.), and subcutaneous (s.c.) administration of a 66-microg dose; and repeated s.c. administration of four 66-microg doses at 48-h intervals. The disposition of IFN-beta1a followed triexponential decay after i.v. administration (half-lives 3 min, 42 min, and 22 h, respectively). After s.c. and i. m. administration, absorption was the rate-limiting factor in the terminal phase. The median absolute bioavailabilities were 30% and 27%, respectively. The accumulation ratio after repeated s.c. injections was 2.4, and a terminal half-life of 66 h was observed. Intracellular 2-5A synthetase activity and serum neopterin and beta2-microglobulin concentrations increased after all IFN-beta1a injections and remained elevated following every-other-day administration. The local tolerance was good, and the systemic tolerance was satisfactory.

Effect of IFNbeta and anti-IFNbeta antibodies on NK cells in multiple sclerosis patients

We analysed longitudinally the numbers of CD3-CD16+ (natural killer cells, NK) and CD3-CD57+ cells (a subset of NK) in 15 IFNbeta1b- and 12 IFNbeta1a-treated relapsing-remitting multiple sclerosis (RRMS) patients. IFNbeta1b (Betaferon)-treated RRMS patients showed a rapid and marked reduction in the number of both NK subsets which started 1 month after therapy initiation, and reached highest significance after 3 months (P=0.000); however, figures reverted to pre-treatment values following the appearance of anti-IFNbeta antibodies. In IFNbeta1a (Avonex)-treated RRMS patients, the decrease in both CD3-CD16+ and CD3-CD57+ cell number was slower but more persistent; anti-IFNbeta antibodies were only rarely detected in these patients, and at lower titers than in IFNbeta1b-treated ones. Our findings suggest that NK cells might be one of the major immunological targets of IFNbeta-based treatments.

The potential role of gene therapy in the treatment of bladder cancer

Based on understanding the molecular mechanism of bladder carcinogenesis, cancer gene therapy may well become a novel therapy in the near future. Currently, a viral vector system appears to be a better vehicle to deliver genes into target cells. Exploring different therapeutic strategies has generated promising results from preclinical bladder cancer models. Phase I clinical trials are underway to study the feasibility of this treatment for human bladder cancer patients. However, several potential problems associated with effective gene delivery need to be further refined.

Pharmacodynamic comparison of single doses of IFN-beta1a and IFN-beta1b in healthy volunteers

In a study in 75 volunteers, preparations of interferon-beta1b (IFN-beta1b) and IFN-beta1a were compared in terms of the resulting serum concentrations of three biologic markers, neopterin, human Mx protein, and 2',5' oligoadenylate synthetase. Each preparation was tested at five dose levels, the middle dose being that recommended for use in patients with multiple sclerosis on the basis of large clinical trials. Five randomly chosen volunteers each received a single subcutaneous dose of one of the IFN or of IFN-beta1a given intramuscularly. The amounts of each marker induced were dose related. There were no major differences between the results with the two IFN or in the duration of the changes in the markers after the two routes of injection. The data indicated that 8 million international units (MIU) of IFN-beta1b and 6 MIU of IFN-beta1a had very similar effects. Even after the highest single dose tested, the increase in the biologic markers were not sustained for a full week.

Influence of interferon beta-1a dose frequency on PBMC cytokine secretion and biological effect markers

Interferon-beta regimens for immune-mediated diseases, such as multiple sclerosis (MS), have not been compared regarding their biological effects. In this randomized, parallel-group, placebo-controlled study, cytokine secretion by mitogen-stimulated PBMCs and serum response markers were assessed in volunteers receiving subcutaneous recombinant IFN beta-1a (Rebif, Ares-Serono) 22 microg once a week (QW), 22 microg three times a week, 66 microg QW, or placebo. The production of IL-1beta, IL-6, IFN-gamma, TNF-alpha and TNF-beta markedly decreased during 24-48 h after each injection, with limited dose-dependency and no evidence of tolerance or effect augmentation over 1 month. IL-10 secretion remained unchanged. The increase in serum beta2-microglobulin, neopterin and 2-5A-synthetase was more sustained. Thus, IFN-beta-induced immunomodulation in vivo strongly depends on the administration schedule, the time-integrated effect being 2-3 times greater when a same weekly dose is divided in three injections.

Interferon-beta gene therapy inhibits tumor formation and causes regression of established tumors in immune-deficient mice

Despite the potential of type 1 interferons (IFNs) for the treatment of cancer, clinical experience with IFN protein therapy of solid tumors has been disappointing. IFN-beta has potent antiproliferative activity against most human tumor cells in vitro in addition to its known immunomodulatory activities. The antiproliferative effect, however, relies on IFN-beta concentrations that cannot be achieved by parenteral protein administration because of rapid protein clearance and systemic toxicities. We demonstrate here that ex vivo IFN-beta gene transduction by a replication-defective adenovirus in as few as 1% of implanted cells blocked tumor formation. Direct in vivo IFN-beta gene delivery into established tumors generated high local concentrations of IFN-beta, inhibited tumor growth, and in many cases caused complete tumor regression. Because the mice were immune-deficient, it is likely that the anti-tumor effect was primarily through direct inhibition of tumor cell proliferation and survival. Based on these studies, we argue that local IFN-beta gene therapy with replication-defective adenoviral vectors might be an effective treatment for some solid tumors.