Connexin 43: A Target for the Treatment of Inflammation in Secondary Complications of the Kidney and Eye in Diabetes.

Of increasing prevalence, diabetes is characterised by elevated blood glucose and chronic inflammation that precedes the onset of multiple secondary complications, including those of the kidney and the eye. As the leading cause of end stage renal disease and blindness in the working population, more than ever is there a demand to develop clinical interventions which can both delay and prevent disease progression. Connexins are membrane bound proteins that can form pores (hemichannels) in the cell membrane. Gated by cellular stress and injury, they open under pathophysiological conditions and in doing so release 'danger signals' including adenosine triphosphate into the extracellular environment. Linked to sterile inflammation via activation of the nod-like receptor protein 3 inflammasome, targeting aberrant hemichannel activity and the release of these danger signals has met with favourable outcomes in multiple models of disease, including secondary complications of diabetes. In this review, we provide a comprehensive update on those studies which document a role for aberrant connexin hemichannel activity in the pathogenesis of both diabetic eye and kidney disease, ahead of evaluating the efficacy of blocking connexin-43 specific hemichannels in these target tissues on tissue health and function.

Danegaptide Prevents TGFß1-Induced Damage in Human Proximal Tubule Epithelial Cells of the Kidney.

Chronic kidney disease (CKD) is a global health problem associated with a number of comorbidities. Recent evidence implicates increased hemichannel-mediated release of adenosine triphosphate (ATP) in the progression of tubulointerstitial fibrosis, the main underlying pathology of CKD. Here, we evaluate the effect of danegaptide on blocking hemichannel-mediated changes in the expression and function of proteins associated with disease progression in tubular epithelial kidney cells. Primary human proximal tubule epithelial cells (hPTECs) were treated with the beta1 isoform of the pro-fibrotic cytokine transforming growth factor (TGFß1) ± danegaptide. qRT-PCR and immunoblotting confirmed mRNA and protein expression, whilst a cytokine antibody array assessed the expression/secretion of proinflammatory and profibrotic cytokines. Carboxyfluorescein dye uptake and ATP biosensing measured hemichannel activity and ATP release, whilst transepithelial electrical resistance was used to assess paracellular permeability. Danegaptide negated carboxyfluorescein dye uptake and ATP release and protected against protein changes associated with tubular injury. Blocking Cx43-mediated ATP release was paralleled by partial restoration of the expression of cell cycle inhibitors, adherens and tight junction proteins and decreased paracellular permeability. Furthermore, danegaptide inhibited TGFß1-induced changes in the expression and secretion of key adipokines, cytokines, chemokines, growth factors and interleukins. The data suggest that as a gap junction modulator and hemichannel blocker, danegaptide has potential in the future treatment of CKD.

Low doses of dasiglucagon consistently increase plasma glucose levels from hypoglycaemia and euglycaemia in people with type 1 diabetes mellitus.

AIM: To characterize the pharmacokinetic and pharmacodynamic properties of dasiglucagon, a novel, stable and liquid formulated glucagon analogue, during hypoglycaemic and euglycaemic conditions in adult patients with type 1 diabetes mellitus. RESEARCH DESIGN AND METHODS: In this randomized double-blind trial, 17 patients received four single subcutaneous doses (0.03, 0.08, 0.2 and 0.6 mg) of dasiglucagon (4 mg/mL formulation) under euglycaemic (plasma glucose [PG] 5.6 mmol/L [100 mg/dL]) or hypoglycaemic (PG 3.1-3.7 mmol/L [56-66 mg/dL]) conditions. For comparison, three doses (0.03, 0.08 and 0.2 mg) of a commercial glucagon formulation (Eli Lilly) were investigated at euglycaemia. RESULTS: Dasiglucagon led to a dose-dependent and rapid increase in PG levels across all doses tested (mean increases 30 minutes post-dosing of 2.2 to 4.4 mmol/L [39-80 mg/dL] from euglycaemia and 1.3 to 5.2 mmol/L [24-94 mg/dL] from hypoglycaemia), which was higher than the rises elicited by similar doses of commercial glucagon (1.7-3.9 mmol/L [30-71 mg/dL]). The median time (range) to an increase in PG of >1.1 mmol/L (20 mg/dL) was <20 (18-19.5) minutes with 0.03 mg dasiglucagon and, with higher doses, the median times ranged from 9 to 15 minutes (commercial glucagon 13-14 minutes). In hypoglycaemia, 0.03 and 0.08 mg dasiglucagon re-established normoglycaemia (PG ≥3.9 mmol/L [70 mg/dL]) within median times of 14 and 10 minutes, respectively. Nausea and vomiting occurred more frequently with dasiglucagon than with commercial glucagon at identical doses which might be attributable to dasiglucagon's higher potency. CONCLUSION: Dasiglucagon rapidly increased PG at doses of 0.03 to 0.6 mg in a dose-dependent manner and, therefore, is a good candidate for use in dual-hormone artificial pancreas systems.

Inhibition of Cx43 gap junction uncoupling prevents high glucose-induced apoptosis and reduces excess cell monolayer permeability in retinal vascular endothelial cells.

The aim of this study was to investigate whether inhibition of connexin 43 gap junction-uncoupling is sufficient to prevent retinal vascular cell loss under high glucose condition and reduce cell monolayer permeability. Rat retinal endothelial cells were grown for 3, 5, and 7 days in normal (5 mM) or high glucose (30 mM) medium; in parallel, cells grown in high glucose medium were exposed for 3, 5, and 7 days to 100 nM danegaptide, which stabilizes connexin 43-mediated cell coupling. Additionally, cells grown in normal medium were treated with a connexin 43 blocker as a negative control. To determine gap junction intercellular communication, scrape load dye transfer assay was performed at the three time points. Cells were assessed for apoptosis and cell monolayer permeability by differential dye staining and in vitro permeability assays, respectively. Cells treated with danegaptide preserved gap junction intercellular communication, decreased cell death, and reduced cell monolayer permeability. Scrape load dye transfer assay indicated that cells exposed to danegaptide for 3, 5, and 7 days under high glucose condition maintained gap junction intercellular communication. Importantly, danegaptide significantly prevented high glucose-induced apoptosis at all three time points, and inhibited cell monolayer permeability by day 5. Cells exposed to a connexin 43 blocker, which decreased cell coupling, showed excess apoptosis and cell monolayer permeability. These findings suggest that prevention of high glucose-induced compromised cell-cell coupling may be a useful strategy for inhibiting apoptosis and excess vascular permeability associated with diabetic retinopathy.

Safety, PK, and PD of recombinant anti-interleukin-21 monoclonal antibody in a first-in-human trial.

OBJECTIVE: This first-in-human, randomized, double-blind, placebo-controlled trial assessed the safety of NNC0114-0005, a human recombinant anti interleukin (IL)-21 monoclonal antibody, for the treatment of rheumatoid arthritis (RA). METHODS AND MATERIALS: Healthy male subjects (HS (n = 44)) and patients with active RA treated with methotrexate (n = 20) were randomized 3 : 1 to single IV or SC doses of NNC0114-0005 (0.0025 - 25 mg/kg) or placebo. Safety endpoints, pharmacokinetics, and pharmacodynamics were assessed over 12 weeks. RESULTS: All study participants were analyzed. 37 AEs were reported in 21 NNC0114-0005-treated participants (44%) and 18 AEs in 10 placebo-treated participants (63%), with no dose-dependency. The most common AEs were headache and nasopharyngitis; there were no injection-site reactions Linear pharmacokinetics of NNC0114-0005 were indicated (mean terminal half-life, 2 - 3 weeks). Dose-dependent total IL-21 (free IL-21 and IL-21‒NNC0114-0005 complexes) accumulation was observed. Preliminary signs of reduced RA activity were observed with 25 mg/kg NNC0114-0005. CONCLUSIONS: Single doses of NNC0114-0005 (≤ 25 mg/kg IV; ≤ 4 mg/kg SC) were well tolerated in HS and patients with RA. Accumulation of IL-21-containing complexes suggests neutralization of the target cytokine. Based< on this trial, further trials to explore the efficacy of anti-IL-21 were initiated.

A phase I study of recombinant human interleukin-21 (rIL-21) in combination with sunitinib in patients with metastatic renal cell carcinoma (RCC).

BACKGROUND: sunitinib induces partial responses in 47% of patients with metastatic renal cell carcinoma (mRCC). However, the achievement of complete responses remains scarce and all patients will eventually develop progressive disease. Recombinant interleukin-21 (rIL-21) is a novel cytokine, which is believed to deliver sustained cellular anti-tumor response and the combination of both agents may work synergistically. MATERIAL AND METHOD: from July 2007 to July 2008 in this phase I trial nine therapy-naive patients with metastatic RCC in five European centers were enrolled. Patients with either good or intermediate risk according to Memorial Sloan-Kettering Cancer Center (MSKCC) were eligible without restrictions to histology subtype nor measurable disease. Patients were treated with increasing doses of rIL-21 administered subcutaneously (s.c.) in combination with sunitinib 50 mg once daily (OD) orally at the '4 weeks on/2 weeks off' schedule. Dose-escalation was applied by a conventional '3+3 design'. Planned dose levels (DL) for rIL-21 were 3, 10, 30 and 100 microg/kg s.c. The primary endpoint was to determine the maximum tolerated dose (MTD) and recommended dose (rd). secondary objectives included pharmacokinetics of sunitinib and ril-21, and the induction of ril-21 antibodies. RESULTS: at 10 microg/kg two dose-limiting toxicities (DLT) occurred in four patients, consisting of grade 4 neutropenia and grade 3 thrombocytopenia. The MTD was 3 microg/kg rIL-21 combined with sunitinib 50 mg OD at the '4 weeks on/2 weeks off' schedule. Frequent occurring adverse events were injection site reaction, stomatitis, fatigue and dysgeusia. CONCLUSIONS: the combination of sunitinib 50 mg at the '4 weeks on/2 weeks off' schedule and 10 microg/kg IL-21 was not tolerated due to hematological DLTs. The dose level of 3 microg/kg rIL-21 was considered too low to be therapeutically relevant for further evaluation and therefore the study was discontinued.

Clinical and biological efficacy of recombinant human interleukin-21 in patients with stage IV malignant melanoma without prior treatment: a phase IIa trial.

PURPOSE: Human interleukin-21 (IL-21) is a class I cytokine that mediates activation of CD8(+) T cells, natural killer (NK) cells, and other cell types. We report final clinical and biological results of a phase II study of recombinant human IL-21 (rIL-21) in patients with metastatic melanoma. EXPERIMENTAL DESIGN: Open-label, single-arm, two-stage trial. ELIGIBILITY CRITERIA: unresectable metastatic melanoma, measurable disease by Response Evaluation Criteria in Solid Tumors, no prior systemic therapy (adjuvant IFN permitted), adequate major organ function, good performance status, no significant autoimmune disease, and life expectancy at least 4 months. PRIMARY OBJECTIVE: antitumor efficacy (response rate). SECONDARY OBJECTIVES: safety, blood biomarkers, and generation of anti-rIL-21 antibodies. rIL-21 (30 microg/kg/dose) was administered by intravenous bolus injection in 8-week cycles (5 dosing days followed by 9 days of rest for 6 weeks and then 2 weeks off treatment). RESULTS: Stage I of the study comprised 14 patients. One confirmed complete response (CR) was observed, and as per protocol, 10 more patients were accrued to stage II (total n = 24: 10 female and 14 male). Best tumor response included one confirmed CR and one confirmed partial response, both with lung metastases. Treatment was overall well tolerated. Biomarker analyses showed increases in serum soluble CD25, frequencies of CD25(+) NK and CD8(+) T cells, and mRNA for IFN-gamma, perforin, and granzyme B in CD8(+) T and NK cells. CONCLUSIONS: rIL-21 administered at 30 microg/kg/d in 5-day cycles every second week is biologically active and well tolerated in patients with metastatic melanoma. Confirmed responses, including one CR, were observed.

Glepaglutide, a novel long-acting glucagon-like peptide-2 analogue, for patients with short bowel syndrome: a randomised phase 2 trial.

BACKGROUND: Patients with short bowel syndrome might have impaired postprandial endogenous glucagon-like peptide-2 (GLP-2) secretion, which is required for optimal intestinal adaptation. We aimed to assess the therapeutic potential of glepaglutide, a novel long-acting GLP-2 analogue, for reducing faecal output and increasing intestinal absorption in patients with short bowel syndrome. METHODS: In this single-centre, double-blind, crossover, randomised phase 2 trial, adults (aged ≥18 to ≤90 years) with short bowel syndrome and with a faecal wet weight output of 1500 g/day or more were randomly assigned to receive one of six dose sequences of glepaglutide (10 mg, 1 mg; 10 mg, 0·1 mg; 1 mg, 10 mg; 1 mg, 0·1 mg; 0·1 mg, 10 mg; or 0·1 mg, 1 mg). Patients received daily subcutaneous injections of the first assigned dose of glepaglutide for 3 weeks, followed by a washout period of 4-8 weeks, and then the second dose of glepaglutide for 3 weeks. An unmasked statistician generated the randomisation list, and the trial investigator enrolled patients and assigned them their patient numbers. Trial investigators, patients, and other care providers were masked throughout the trial. The primary endpoint was the absolute change from baseline in faecal wet weight output, measured separately over the two treatment periods. Metabolic balance studies were done before and after each treatment period to assess the primary endpoint. Per-protocol analysis was used to assess the efficacy. Safety analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT02690025, and has completed. FINDINGS: Of the 22 patients screened between Feb 5, 2016, and Jan 25, 2017, 18 patients were randomly assigned and treated with glepaglutide; 16 patients completed the trial. Treatment with 1 mg and 10 mg glepaglutide changed the adjusted mean faecal output by -592 g/day (95% CI -913 to -272; p=0·002) and -833 g/day (-1152 to -515; p=0·0002) from baseline, respectively. No changes were observed with 0·1 mg glepaglutide. Of the 18 patients who were randomly assigned to treatment, common treatment-related adverse events were stoma complications (13 [72%] patients), injection site reactions (11 [61%]), peripheral oedema (ten [56%]), nausea and abdominal pain (eight [44%] each), polyuria and fatigue (six [33%] each), abdominal distention, vomiting, and dizziness (five [28%] each); and cough and decreased appetite (four [22%] each). Related or possibly related serious adverse events were reported in two patients in the 0·1 mg dose group and two patients in the 10 mg dose group. These events included abdominal pain, stoma obstruction, catheter-related sepsis, and infection of unknown origin. No patients died during the trial. INTERPRETATION: Glepaglutide was well tolerated, and was associated with improved intestinal absorption in patients with short bowel syndrome with 1 mg and 10 mg glepaglutide, but not with 0·1 mg glepaglutide. Larger phase 3 clinical trials of longer durations have been initiated to fully assess the safety and efficacy of glepaglutide. FUNDING: Zealand Pharma.

Pharmacokinetic and Pharmacodynamic Characteristics of Dasiglucagon, a Novel Soluble and Stable Glucagon Analog.

OBJECTIVE: Treatment of severe hypoglycemia outside of the hospital setting is limited to glucagon formulations requiring reconstitution before use, which may lead to erroneous or delayed glucagon administration. We compared the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics and safety and tolerability of different doses of dasiglucagon, a novel soluble glucagon analog, with approved pediatric and full doses of GlucaGen in insulin-induced hypoglycemia in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: In this single-center, randomized, double-blind trial, 58 patients with type 1 diabetes received single subcutaneous injections of 0.1, 0.3, 0.6, or 1.0 mg dasiglucagon or 0.5 or 1.0 mg GlucaGen in a state of hypoglycemia (blood glucose target 55 mg/dL) induced by an intravenous insulin infusion. RESULTS: Dasiglucagon demonstrated a dose-dependent and rapid increase in plasma concentrations, reaching a maximum at ∼35 min with a half-life of ∼0.5 h. Dasiglucagon rapidly increased plasma glucose (PG) by ≥20 mg/dL (9-14 min) to PG ≥70 mg/dL (within 6-10 min), similar to GlucaGen, but with a longer-lasting and greater effect on PG. All patients on both treatments reached these end points within 30 min (predefined success criteria). Both treatments were well tolerated. Nausea was the most frequent adverse event, occurring at a similar rate (44-56%). CONCLUSIONS: Dasiglucagon was well tolerated and showed an early PD response similar to that of GlucaGen at corresponding doses, suggesting comparable clinical effects of the two glucagon formulations. Dasiglucagon has the potential to become an effective and reliable rescue treatment for severe hypoglycemia in a ready-to-use pen.

Danegaptide for primary percutaneous coronary intervention in acute myocardial infarction patients: a phase 2 randomised clinical trial.

OBJECTIVES: Reperfusion immediately after reopening of the infarct-related artery in ST-segment elevation myocardial infarction (STEMI) may cause myocardial damage in addition to the ischaemic insult (reperfusion injury). The gap junction modulating peptide danegaptide has in animal models reduced this injury. We evaluated the effect of danegaptide on myocardial salvage in patients with STEMI. METHODS: In addition to primary percutaneous coronary intervention in STEMI patients with thrombolysis in myocardial infarction flow 0-1, single vessel disease and ischaemia time less than 6 hours, we tested, in a clinical proof-of-concept study, the therapeutic potential of danegaptide at two-dose levels. Primary outcome was myocardial salvage evaluated by cardiac MRI after 3 months. RESULTS: From November 2013 to August 2015, a total of 585 patients were randomly enrolled in the trial. Imaging criteria were fulfilled for 79 (high dose), 80 (low dose) and 84 (placebo) patients eligible for the per-protocol analysis. Danegaptide did not affect the myocardial salvage index (danegaptide high (63.9±14.9), danegaptide low (65.6±15.6) and control (66.7±11.7), P=0.40), final infarct size (danegaptide high (19.6±11.4 g), danegaptide low (18.6±9.6 g) and control (21.4±15.0 g), P=0.88) or left ventricular ejection fraction (danegaptide high (53.9%±9.5%), danegaptide low (52.7%±10.3%) and control (52.1%±10.9%), P=0.64). There was no difference between groups with regard to clinical outcome. CONCLUSIONS: Administration of danegaptide to patients with STEMI did not improve myocardial salvage. TRIAL REGISTRATION NUMBER: NCT01977755; Pre-results.

Suppression of elevated cartilage turnover in postmenopausal women and in ovariectomized rats by estrogen and a selective estrogen-receptor modulator (SERM).

OBJECTIVE: Several observational studies indicate that estrogen deficiency increases the incidence of osteoarthritis in postmenopausal women. To validate this observation, we investigated the effects of ovariectomy (OVX) on cartilage erosion in rats using histology and an established bio-assay of cartilage-specific collagen type II degradation products (CTX-II). Furthermore, we investigated whether estrogen and levormeloxifene, a selective estrogen-receptor modulator (SERM), can prevent the OVX-induced changes in cartilage degradation. The clinical relevance was assessed in postmenopausal women by measuring the changes in CTX-II during 12-month treatment with levormeloxifene versus placebo. DESIGN: Sixty 6-month-old rats were divided in five groups. One group was subjected to sham and the others to OVX, followed by treatment with vehicle alone, estradiol or 0.2 mg/kg/day or 5 mg/kg/day of levormeloxifene. The rats were treated for 9 weeks with biweekly blood and urine sampling for measurement of bone resorption and cartilage turnover. After study termination, hind knees were removed for histological analysis of erosions. The effect of levormeloxifene in post-menopausal women was assessed by measuring CTX-II in samples from 301 women who were participating in a phase II study of this SERM. RESULTS: OVX rats showed significant increases in the urinary excretion of CTX-II. After 9 weeks this was manifested as increased surface erosion of knee articular cartilage compared with sham-operated rats. Treatment with estrogen or levormeloxifene prevented the OVX-induced changes. There was a significant correlation between the 4-week changes in CTX-II and cartilage erosion at week 9 (r = 0.64, P < 0.001). In postmenopausal women treated with levormeloxifene, the urinary excretion of CTX-II was decreased by approximately 50% and restored CTX-II levels to the premenopausal range. CONCLUSIONS: This study is the first to demonstrate that a SERM suppresses cartilage degradation in both rodents and humans, suggesting potential therapeutical benefits in the prevention of destructive joint diseases such as osteoarthritis.

Appendicular lean tissue mass and the prevalence of sarcopenia among healthy women.

Studies indicate that deficient skeletal muscle mass or sarcopenia is a major cause of disability and morbidity among the elderly. In part, due to the lack of generally applicable normal values, there is still insufficient epidemiologic data available on the frequency and severity of sarcopenia in health and under various disease-related conditions. The objectives of the present study were to (1) characterize the age- and menopause-related variations in appendicular lean tissue mass (LTM(A)), (2) provide young-normal means and estimate the age-specific prevalence of sarcopenia among healthy women. A total of 754 healthy women were included in the study of cross-sectional design. LTM(A) was estimated by dual-energy x-ray absorptiometry (DEXA). Physical characteristics and menopausal status were also registered. LTM(A) as well as height showed significant negative correlation with age with Pearson's r values of -0.43 and -0.06, respectively (P <.05). Trend of finding lower mean values with advancing age remained even when LTM(A) was adjusted for height(2) (ht(2)). Menopause did not seem to have any influence on LTM(A). Young-normal means were obtained from 216 premenopausal women aged 18 to 39 years. Prevalence rates of sarcopenia in healthy women were determined with reference to a cut-off line corresponding to LTM(A) or LTM(A)/ht(2) less than young-normal mean 2 SD and were found to be 40.2% and 12.3%, respectively, among the healthy elderly (>70 years of age). Results of the present study provide further evidence that sarcopenia exists even among otherwise healthy women with increasing age-specific prevalence. Further studies are needed (1) to estimate the prevalence of sarcopenia under various health and disease-related conditions with reference to the hereby given cut-off values and (2) to find therapeutic strategies with beneficial effects in conserving skeletal muscle mass.

Addition of biphasic insulin aspart 30 to rosiglitazone in type 2 diabetes mellitus that is poorly controlled with glibenclamide monotherapy.

BACKGROUND: The incidence of type 2 diabetes mellitus (DM) is rapidly increasing worldwide. Results from large-scale studies show that tight blood glucose (BG) control improves the outcome of patients with type 2 DM. OBJECTIVE: This trial assessed the short-term efficacy and tolerability of adding a thiazolidinedione (rosiglitazone [ROS]) to existing sulfonylurea (SU) therapy (glibenclamide) compared with switching to combination treatment with a premixed insulin (biphasic insulin aspart 30 [BIAsp 30], a rapid-acting insulin analog) and the thiazolidinedione in a select group of patients with type 2 DM whose metabolic control was inadequate with SU monotherapy. METHODS: In this 6-week, multicenter, open-label, parallel-group trial, patients with type 2 DM whose BG level was not adequately controlled with glibenclamide monotherapy (glycosylated hemoglobin [HbA1c] 8%-13%) were randomized either to replace glibenclamide with BIAsp 30 (individually titrated dosages starting with 6-8 U BID) plus rosiglitazone (4 mg once daily) (BIAsp 30 + ROS group) or to add rosiglitazone (4 mg once daily) to their pretrial doses of glibenclamide (GLIB + ROS group). Patients measured their BG levels immediately before each of the 3 main meals, 90 minutes after the start of each meal, and at bedtime, and mean BG levels were calculated at weeks 0 (baseline), 1, 2, 4, 6, and at 2-week follow-up (week 8). The primary end point was change in mean daily BG level during treatment. Secondary end points included preprandial, postprandial, and bedtime BG levels, serum fructosamine level HbA, and fasting BG level, which were measured at each study visit. Tolerability was assessed using hematologic and biochemical parameters, vital signs, and physical examination. RESULTS: Forty-nine patients (32 men, 17 women; mean [SD] age, 59.1 [8.9] years; mean [SD] body mass index, 27.7 [3.7] kg/m2) participated in the study. A significant difference was found between treatments in the change in mean daily BG level from baseline to week 6 (P=0.01). After the 6-week treatment period, change in mean serum fructosamine level was significantly greater for BIAsp 30 + ROS compared with GLIB + ROS (P=0.02). HbA1c decreased in both treatment groups from baseline to study end, but the difference between groups was nonsignificant. The changes in fasting BG from baseline to study end also were nonsignificant between groups. Both combinations were well tolerated. CONCLUSIONS: This short-term study in patients with type 2 DM whose BG level was poorly controlled with glibenclamide monotherapy suggests that switching to a combination of BIAsp 30 + ROS was efficacious and well tolerated and provided an alternative to adding rosiglitazone to existing glibenclamide treatment. The study also suggests that BIAsp 30 may be associated with greater improvements in short-term metabolic control.

Safety and clinical effect of subcutaneous human interleukin-21 in patients with metastatic melanoma or renal cell carcinoma: a phase I trial.

PURPOSE: This phase I study in patients with metastatic melanoma (MM) and renal cell carcinoma (RCC) evaluated the safety and maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of s.c. treatment of human recombinant interleukin 21 (IL-21). EXPERIMENTAL DESIGN: Phase I dose-escalation trial with treatment of three to six patients at each dose level, escalating from 3 to 300 µg/kg. Treatment was administered s.c. on an outpatient basis 3 days per week for 8 or 16 weeks. RESULTS: Twenty-six patients entered the study. Recombinant IL-21 was generally well tolerated, and dose-limiting toxicities (DLT) were first seen at dose levels of 200 and 300 µg/kg. The following four DLTs were observed in three patients: increased transaminases, increased hyperbilirubinemia, hypersensitivity reaction, and lethargy. The MTD was declared to be 200 µg/kg, although five of seven patients at the 300 µg/kg dose level experienced no DLTs. A treatment-related effect on soluble CD25 was observed at all dose levels and increased with dose level. Furthermore, higher doses induced interferon-γ, perforin, and granzyme B mRNA expression in peripheral blood, and granzyme B protein expression in both CD8(+) T cells and natural killer cells, consistent with the activation of cytotoxic lymphocytes. Three patients, one patient with MM and two with RCC, obtained a partial response. CONCLUSION: Outpatient treatment with s.c. administered IL-21 was tolerated and had dose-dependent pharmacodynamics. rIL-21 showed antitumor activity in patients with MM and RCC.