Disposition of recombinant human interleukin-10 in subjects with various degrees of renal function

Tissue distribution of 35S-metabolically labeled neublastin (BG00010) in rats

Neublastin (NBN) is a neurotrophic growth factor that promotes the survival and regenerative properties of nociceptive neurons and has been tested in clinical trials as a treatment for neuropathic pain in individuals with sciatica and painful lumbosacral radiculopathy. Like many low molecular weight heparin binding proteins, NBN is rapidly cleared from the blood following systemic administration. To explore ADME properties of NBN in rats, we used metabolically ³⁵S-labeled NBN following IV and SC administration quantifying counts and intact protein in kidney, liver, brain, serum, and urine at 5 min, 8 h, 24 h and 48 h, and biodistribution in whole body carcasses by QWBA at 2, 8, 48, 96, and 168 h post dose. NBN is rapidly taken up by tissues mainly by liver and kidney and then degraded. Products of degradation are excreted in urine or recycled and utilized for resynthesis. The data we generated for NBN provides a first look at the complex clearance mechanisms for this protein and should aid in the design of ADME studies for other heparin binding proteins.

Are hepatic impairment studies necessary for therapeutic proteins?

OBJECTIVE

This study assessed whether trials to investigate the effect of hepatic impairment on the pharmacokinetics of therapeutic proteins (TPs), which are conducted for small molecule drugs, are necessary.

METHODS

The product labeling for 91 TPs that have been approved by the US Food and Drug Administration were reviewed. A PubMed search was also conducted to identify completed studies that assessed the effect of hepatic impairment on the pharmacokinetics of TPs. Biologic License Applications were subsequently reviewed to gather further descriptions of the trials conducted in patients with hepatic impairment and data analyses.

RESULTS

No dedicated pharmacokinetics trials were conducted in patients with hepatic impairment for these approved TPs, but subgroup (n = 2 [2.2%]) or population (n = 5 [5.5%]) pharmacokinetic analyses were performed for 7 TPs. The pharmacokinetics of these proteins were not affected by the hepatic dysfunction, with the exception that the clearance of drotrecogin alfa seemed 25% higher in patients with hepatic impairment than in patients without hepatic impairment; however, no dose reduction was recommended. Thus, the effect of hepatic impairment on the pharmacokinetics of TPs is unclear based on the limited analyses completed to date.

CONCLUSIONS

A dedicated pharmacokinetics trial for TPs in patients with hepatic impairment is not necessary. Recognizing that the data are very limited, it would be important to continue collecting pharmacokinetic data of TP in patients with hepatic impairment and using population pharmacokinetic analyses to evaluate the effect of hepatic impairment on the pharmacokinetics of TP.

Characterizing the impact of renal impairment on the clinical pharmacology of biologics

Similar to small-molecule drugs, there is also concern for protein-based therapeutics about their clinical use in patients with renal impairment including renal insufficiency and end-stage renal disease, which may modulate the efficacy and/or safety profile of these compounds. Theoretical considerations and clinical evidence suggest that the kidneys play a relevant role in the catabolism and thus elimination of only those protein therapeutics that have a size below the cutoff for glomerular filtration of approximately 60 kDa. Thus, the effect of renal impairment on protein therapeutics seems to be predictable and only relevant for compounds below this molecular weight cutoff. This is supported by clinical evidence that shows a lack of effect of renal impairment on large proteins such as monoclonal antibodies, whereas smaller proteins below the cutoff such as interleukin-10, growth hormone, erythropoietin, and anakinra experience a gradual decrease of their clearance and increase of their systemic exposure with increasing severity of renal impairment. Thus, dedicated renal impairment studies are warranted in the clinical development program of protein therapeutics that undergo glomerular filtration to establish the scientific rationale for their safe and efficacious use in patients with renal insufficiency.

Human interleukin-10 gene transfer is protective in a rat model of Parkinson's disease

In Parkinson's disease (PD) chronic inflammation occurs in the substantia nigra (SNc) concurrently with dopaminergic neurodegeneration. In models of PD, microglial activation precedes neurodegeneration in the SNc, suggesting that the underlying pathogenesis involves a complex response in the nigrostriatal pathway, and that the innate immune system plays a significant role. We have investigated the neuroprotective effect of an adeno-associated viral type-2 (AAV2) vector containing the complementary DNA (cDNA) for human interleukin-10 (hIL-10) in the unilateral 6-hydroxydopamine (6-OHDA) rat model of PD. AAV2-hIL-10 reduced the 6-OHDA-induced loss of tyrosine hydroxylase (TH)-positive neurons in the SNc, and also reduced loss of striatal dopamine (DA). Pretreatment with AAV2-hIL-10 reduced glial activation in the SNc but did not attenuate striatal release of the inflammatory cytokine IL-1beta. Assessment of rotational behavior in response to apomorphine challenge showed absence of asymmetry, confirming protection of dopaminergic innervation of the lesioned striatum. At baseline, 6-OHDA-lesioned animals displayed a deficit in contralateral forelimb use, but pretreatment with AAV2-hIL-10 reduced this forelimb akinesia. Transcriptional analyses revealed alteration of a few genes by AAV2-hIL-10; these alterations may contribute to neuroprotection. This study supports the need for further investigations relating to gene therapies aimed at reducing neuroinflammation in early PD.

Renal cytokine profile in an endotoxemic porcine model

INTRODUCTION

In animals exposed to acute endotoxemia with lipopolysaccharide (LPS), high levels of cytokines are found in the kidney. The objective of this study is to determine whether the high renal content of TNF-alpha, IL-1beta, IL-10 and IL-1 receptor antagonist (IL-1ra) is due to glomerular filtration and reabsorption, or whether the cytokines are produced locally in the kidney.

METHODS

Eighteen anesthetized and mechanically ventilated pigs (35-43 kg) were randomized into two groups: Group 1 (n=12) LPS infusion for 360 min and Group 2 (n=6) control pigs, no treatment. At 360 min, the pigs were euthanized and tissue samples from the kidneys were obtained. Localization of the cytokines was determined by immunohistochemistry and double immunofluorescence (dIF).

RESULTS

Pigs exposed to endotoxemia showed increased accumulation of leukocytes and increased protein expression of TNF-alpha and IL-1beta when compared with controls. dIF showed that TNF-alpha-positive cells co-localized with both endothelial and mesangial cells in the glomeruli. Furthermore, the endothelial cells of the cortical arterioles were positive for IL-1beta. TNF-alpha and IL-1beta staining were absent in renal tubular cells. A positive signal for IL-10 was detected at the tubular brush border while IL-1ra was detected in the glomerulus and in the tubular cells.

CONCLUSION

LPS-induced endotoxemia increased TNF-alpha and IL-1beta protein expression and leukocyte accumulation in the kidneys. The results indicate that the increased levels of the pro-inflammatory cytokines TNF-alpha and IL-1beta are caused by a local production in the kidneys while the anti-inflammatory cytokines IL-10 and IL-1ra are filtrated and reabsorbed in the tubuli.

Paradoxical effects of cytokines in tumor immune surveillance and tumor immune escape

The role of cytokines in modulating the formation of new tumors is mediated by their ability to regulate antigen-specific anti-tumor responses and by the activation of non-specific mechanisms, including those involved in the processes of inflammation and innate resistance. Cytokines may influence the growth of tumors by acting directly on tumor cells as growth promoting or growth inhibiting factors or indirectly by attracting inflammatory cell types and affecting angiogenesis. Due to the potency and complexity of cytokine activity against tumor growth, the improvement of cloning techniques and the availability of recombinant forms of different cytokines, a great effort has been made in the recent years to exploit this anti-tumor potential for cancer therapy. This important goal has been difficult to achieve in most cases due to toxicity of most cytokines which could not be dissociated from their anti-tumoral functions. Nevertheless, if well designed, treatment protocols and/or modifications of the cytokine molecules may in some situations augment the anti-tumor effects while limiting the toxicity. One of these molecular approaches could be the design of peptides containing the functional domain of certain cytokines, exemplified by IT9302, a peptide homologous to the functional domain of IL-10, which has demonstrated to increase tumor NK cell sensitivity.

Chemical modification of interleukin-10 with mannose 6-phosphate groups yields a liver-selective cytokine

Cytokines are considered a promising immunotherapy for chronic diseases, because of their potency and fundamental roles in pathological processes. However, their therapeutic use is limited because of their poor pharmacokinetics and pleiotropic effects in various organs. These problems may be overcome by cell-specific delivery of the cytokine. This approach involves chemical modification of the protein with homing devices that recognize receptors on target cells. The cytokine interleukin-10 (IL10) may be valuable as a therapeutic cytokine for patients with liver cirrhosis. However, its rapid renal elimination and general immunosuppressive activities limit therapeutic use. We therefore aim to target this cytokine in the liver, in particular to fibrogenic hepatic stellate cells (HSCs). We show that IL10 is successfully modified with mannose 6-phosphate (M6P), which is a homing device for the mannose 6-phosphate/insulin-like growth factor II (M6P/IGFII) receptor expressed on activated HSCs. Chemical modification did not diminish IL10 efficacy with regard to in vitro anti-inflammatory (lipopolysaccharide-stimulated tumor necrosis factor alpha release) and antifibrotic (collagen deposition and degradation) activities. Biodistribution studies with radiolabeled M6P-IL10 and IL10 in rats with liver fibrosis showed that modification with M6P groups induced a shift in the distribution from the kidneys (IL10) to the liver (M6P-IL10). Hepatocellular binding of M6P-IL10 occurred via M6P/IGFII receptors and scavenger receptors, indicating that not only HSCs but also Kupffer and endothelial cells are target cells. IL10 did not bind to these receptors. We conclude that we prepared an active and liver-specific form of the cytokine IL10 that can be evaluated for its efficacy to treat liver diseases.

Electroporative interleukin-10 gene transfer ameliorates carbon tetrachloride-induced murine liver fibrosis by MMP and TIMP modulation

AIM

Liver fibrosis represents a process of healing and scarring in response to chronic liver injury. Effective therapies for liver fibrosis are lacking. Interleukin-10 (IL-10) is a cytokine that downregulates pro-inflammatory responses and has a modulatory effect on hepatic fibrogenesis. The aim of this study was to investigate whether electroporative IL-10 gene therapy has a hepatic fibrolytic effect on mice.

METHODS

Hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) for 10 weeks in mice. The human IL-10 expression plasmid was delivered via electroporation after hepatic fibrosis was established. Histopathology, reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and gelatin zymography were used to investigate the possible mechanisms of action of IL-10.

RESULTS

Human IL-10 gene therapy reversed CCl4-induced liver fibrosis in mice. RT-PCR revealed that IL-10 gene therapy attenuated liver TGF-beta1, collagen alpha1, fibronectin, and cell adhesion molecule mRNA upregulation. Following gene transfer, both the activation of alpha-smooth muscle actin and cyclooxygenase-2 were significantly attenuated. Furthermore, IL-10 significantly inhibited matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of matrix metalloproteinase (TIMP) activation after CCl4 intoxication.

CONCLUSIONS

We demonstrated that IL-10 gene therapy attenuated CCl4-induced liver fibrosis in mice. IL-10 prevented upregulated fibrogenic and pro-inflammatory gene responses. Its collagenolytic effect may be attributed to MMP and TIMP modulation. IL-10 gene therapy may be an effective therapeutic modality against liver fibrosis with potential clinical use.

Pharmacokinetic and biodistribution profile of recombinant human interleukin-10 following intravenous administration in rats with extensive liver fibrosis

PURPOSE

Because interleukin-10 (IL-10) seems a promising new antifibrotic drug, we investigated the pharmacokinetic and biodistribution profile of this potent therapeutic cytokine in rats with extensive liver fibrosis (BDL-3). IL-10 receptor expression was also determined in relation to these aspects.

METHODS

To study the pharmacokinetic and biodistribution of IL-10, rhIL-10 was labeled with 125-iodine. Plasma samples of 125IrhIL-10 were obtained over a 30-min time period after administration of radiolabeled-cytokine to BDL-3 and normal rats. The tissue distribution was assessed 10 and 30 min after i.v. administration of 125IrhlL-10. IL-10 receptor expression was determined by immurohistochemical staining and RT-PCR technique.

RESULTS

. The 125IrhIL-10 plasma curves followed two-compartment kinetics with a lower AUC in BDL-3 rats as compared to control. Plasma clearance and distribution volume at steady state were larger in BDL-3 rats. Tissue distribution analysis in normal rats showed that 125IrhIL-10 highly accumulated in kidneys. In BDL-3 rats, the liver content of 125IrhIL-10 increased by a factor of 2, whereas kidney accumulation did not significantly change. Immunohistochemical staining and RT-PCR analysis showed that IL-10 receptor was clearly upregulated in BDL-3 rat livers.

CONCLUSIONS

. In normal rats, 125IrhIL-10 rapidly disappears from the circulation, and the kidney is predominantly responsible for this. In BDL-3 rats, the liver largely contributes to this rapid plasma disappearance, probably due to an increase in IL-10 receptor expression. The extensive renal clearance of IL-10 in vivo may limit a clinical application of this cytokine for the treatment of chronic liver diseases. To optimize the therapeutic effects of IL-10 in hepatic diseases, alternative approaches that either decrease renal disposition or that further enhance hepatic delivery should be considered.

Interleukin-10 therapy--review of a new approach

Interleukin (IL)-10 is an important immunoregulatory cytokine produced by many cell populations. Its main biological function seems to be the limitation and termination of inflammatory responses and the regulation of differentiation and proliferation of several immune cells such as T cells, B cells, natural killer cells, antigen-presenting cells, mast cells, and granulocytes. However, very recent data suggest IL-10 also mediates immunostimulatory properties that help to eliminate infectious and noninfectious particles with limited inflammation. Numerous investigations, including expression analyses in patients, in vitro and animal experiments suggest a major impact of IL-10 in inflammatory, malignant, and autoimmune diseases. So IL-10 overexpression was found in certain tumors as melanoma and several lymphomas and is considered to promote further tumor development. Systemic IL-10 release is a powerful tool of the central nervous system to prevent hyperinflammatory processes by activation of the neuro-endocrine axis following acute stress reactions. In contrast, a relative IL-10 deficiency has been observed and is regarded to be of pathophysiological relevance in certain inflammatory disorders characterized by a type 1 cytokine pattern such as psoriasis. Recombinant human IL-10 has been produced and is currently being tested in clinical trials. This includes rheumatoid arthritis, inflammatory bowel disease, psoriasis, organ transplantation, and chronic hepatitis C. The results are heterogeneous. They give new insight into the immunobiology of IL-10 and suggest that the IL-10/IL-10 receptor system may become a new therapeutic target.

Interleukin-10 and the interleukin-10 receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Interleukin-10 and the Interleukin-10 Receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.