Efficacy and safety of bimekizumab in axial spondyloarthritis: results of two parallel phase 3 randomised controlled trials.

OBJECTIVES: Axial spondyloarthritis (axSpA) is a complex disease with diverse manifestations, for which new treatment options are warranted. BE MOBILE 1 (non-radiographic (nr)-axSpA) and BE MOBILE 2 (radiographic axSpA (r-axSpA)) are double-blind, phase 3 trials designed to evaluate efficacy and safety of bimekizumab, a novel dual interleukin (IL)-17A and IL-17F inhibitor, across the axSpA spectrum. METHODS: In parallel 52-week trials, patients with active disease were randomised 1:1 (nr-axSpA) or 2:1 (r-axSpA) to bimekizumab 160 mg every 4 weeks:placebo. From week 16, all patients received bimekizumab 160 mg every 4 weeks. Primary (Assessment of SpondyloArthritis international Society ≥40% improvement (ASAS40)) and secondary endpoints were assessed at week 16. Here, efficacy and treatment-emergent adverse events (TEAEs) are reported up to week 24. RESULTS: 254 patients with nr-axSpA and 332 with r-axSpA were randomised. At week 16, primary (ASAS40, nr-axSpA: 47.7% bimekizumab vs 21.4% placebo; r-axSpA: 44.8% vs 22.5%; p<0.001) and all ranked secondary endpoints were met in both trials. ASAS40 responses were similar across TNFi-naïve and TNFi-inadequate responder patients. Improvements were observed in Ankylosing Spondylitis Disease Activity Score (ASDAS) states and objective measures of inflammation, including high-sensitivity C-reactive protein (hs-CRP) and MRI of the sacroiliac joints and spine. Most frequent TEAEs with bimekizumab (>3%) included nasopharyngitis, upper respiratory tract infection, pharyngitis, diarrhoea, headache and oral candidiasis. More fungal infections (all localised) were observed with bimekizumab vs placebo; no major adverse cardiovascular events (MACE) or active tuberculosis were reported. Incidence of uveitis and adjudicated inflammatory bowel disease was low. CONCLUSIONS: Dual inhibition of IL-17A and IL-17F with bimekizumab resulted in significant and rapid improvements in efficacy outcomes vs placebo and was well tolerated in patients with nr-axSpA and r-axSpA.

Safety and Efficacy of Bimekizumab in Patients With Active Ankylosing Spondylitis: Three-Year Results From a Phase IIb Randomized Controlled Trial and Its Open-Label Extension Study.

OBJECTIVE: To assess the long-term safety, tolerability, and efficacy of bimekizumab in patients with active ankylosing spondylitis (AS). METHODS: Patients with active AS who completed the dose-ranging, 48-week BE AGILE randomized controlled trial were eligible to participate in an open-label extension (OLE) study, in which patients received 160 mg of bimekizumab every 4 weeks. We present the safety and efficacy results through 156 weeks. Missing efficacy data were imputed using nonresponder imputation analysis for binary outcomes and multiple imputation for continuous outcomes. RESULTS: From weeks 0-156, 280 of 303 patients (exposure-adjusted incidence rate 141.0 per 100 patient-years) experienced ≥1 treatment-emergent adverse event; the most frequent adverse events were nasopharyngitis (8.1 per 100 patient-years) and upper respiratory tract infection (5.0 per 100 patient-years). Additionally, 67 of 303 patients (9.8 per 100 patient-years) had mild to moderate localized fungal infections (28 of 303 patients had Candida infections [3.7 per 100 patient-years] and 23 of 303 patients had oral candidiasis [3.0 per 100 patient-years]), 10 patients had serious infections (1.3 per 100 patient-years), and no cases of active tuberculosis were reported. Active inflammatory bowel disease (1.1 per 100 patient-years), anterior uveitis (0.7 per 100 patient-years), and adjudicated major adverse cardiovascular events (0.3 per 100 patient-years) were infrequent. The efficacy of bimekizumab treatment demonstrated at week 48 was sustained in the OLE study. At week 156, nonresponder imputation analysis showed that 53.7% of patients (72.6% of observed cases) met the Assessment of SpondyloArthritis international Society criteria for 40% improvement and 28.0% of patients (37.9% of observed cases) achieved partial remission; Ankylosing Spondylitis Disease Activity Scores were reduced from baseline (mean ± SEM 3.9 ± 0.1) to week 48 (2.1 ± 0.1) and week 156 (1.9 ± 0.1) (multiple imputation). Patients showed sustained improvements in pain, fatigue, physical function, and health-related quality of life. CONCLUSION: The safety profile of bimekizumab was found to be consistent with previously demonstrated findings, and no new safety signals were identified. The efficacy of bimekizumab in patients with AS was sustained through 3 years of treatment.

Minimal Impact of the COVID-19 Pandemic on Disease Activity and Health-Related Quality of Life in Patients With Ankylosing Spondylitis Receiving Bimekizumab: Exploratory Analyses From a Phase 2b Open-Label Extension Study.

OBJECTIVE: The impact of the COVID-19 pandemic on patients with inflammatory rheumatic diseases, such as ankylosing spondylitis (AS), has been variable. Here, we assess disease activity and health-related quality of life (HRQoL) through the pandemic in patients with AS. METHODS: In the open-label extension (OLE) of the phase 2b BE AGILE study, patients with AS received 160 mg of subcutaneous bimekizumab every 4 weeks. We assessed Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Quality of Life (ASQoL) scores in the OLE immediately before and during the COVID-19 pandemic (September 2019 to April 2021). RESULTS: A total of 232 patients remained in the BE AGILE OLE and were included in this post hoc study at the start of the analysis period (September 1, 2019); 12 patients had a COVID-19 treatment-emergent adverse event, and no cases resulted in death. The number of missed bimekizumab doses due to COVID-19 (11 doses) was minimal, and missed assessments remained low (≤5%) compared with the prepandemic period. Mean ASDAS-CRP (1.8), BASDAI (2.4), and ASQoL scores (2.8) in the OLE were low at pre-pandemic baseline and remained stable at 1.7 to 1.8, 2.2 to 2.4, and 2.0 to 2.8, respectively, across successive 3-month periods immediately before and during the pandemic. ASDAS-CRP, BASDAI, and ASQoL stability was consistent across major study countries. CONCLUSION: Disease activity and HRQoL remained stable during the COVID-19 pandemic in patients with AS receiving bimekizumab in the BE AGILE OLE, with no indication of negative effects on these outcomes.

Dual neutralisation of interleukin-17A and interleukin-17F with bimekizumab in patients with active ankylosing spondylitis: results from a 48-week phase IIb, randomised, double-blind, placebo-controlled, dose-ranging study.

OBJECTIVES: Bimekizumab selectively neutralises both interleukin (IL)-17A and IL-17F. We report efficacy and safety in a phase IIb dose-ranging study in patients with active ankylosing spondylitis (AS). METHODS: Adults with AS (fulfilling modified New York criteria) were randomised 1:1:1:1:1 to bimekizumab 16 mg, 64 mg, 160 mg, 320 mg or placebo every 4 weeks for 12 weeks (double-blind period). At week 12, patients receiving bimekizumab 16 mg, 64 mg or placebo were re-randomised 1:1 to bimekizumab 160 mg or 320 mg every 4 weeks to week 48; other patients continued on their initial dose (dose-blind period). The primary end point was Assessment of SpondyloArthritis international Society (ASAS) 40 response at week 12 (non-responder imputation (NRI) for missing data). RESULTS: 303 patients were randomised: bimekizumab 16 mg (n=61), 64 mg (n=61), 160 mg (n=60), 320 mg (n=61) or placebo (n=60). At week 12, significantly more bimekizumab-treated patients achieved ASAS40 vs placebo (NRI: 29.5%-46.7% vs 13.3%; p<0.05 all comparisons; OR vs placebo 2.6-5.5 (95% CI 1.0 to 12.9)). A significant dose-response was observed (p<0.001). The primary end point was supported by all secondary efficacy outcomes. At week 48, 58.6% and 62.3% of patients receiving bimekizumab 160 and 320 mg throughout the study achieved ASAS40, respectively (NRI); similar ASAS40 response rates were observed in re-randomised patients. During the double-blind period, treatment-emergent adverse events occurred in 26/60 (43.3%) patients receiving placebo and 92/243 (37.9%) receiving bimekizumab. CONCLUSIONS: Bimekizumab provided rapid and sustained improvements in key outcome measures in patients with active AS, with no unexpected safety findings versus previous studies. TRIAL REGISTRATION NUMBER: NCT02963506.

Randomized, double-blind, crossover study of the adhesiveness of two formulations of rotigotine transdermal patch in patients with Parkinson's disease.

OBJECTIVE: In patch-based transdermal drug delivery, adhesiveness is critical for safe and effective treatment, especially in Parkinson's disease (PD) where excessive sweating is common. This study compared the adhesiveness of two transdermal patch formulations of rotigotine (improved room temperature-stable [PR2.3.1/Treatment A] and intermediate cold storage product [PR2.1.1/Treatment B]), using the largest patch size (40 cm2). METHODS: PD0018 (NCT02230904) was a multicenter, randomized, double-blind, crossover study. PD patients received Treatments A and B in randomized order for 2 days each. Patch adhesiveness was measured immediately after patch application and 24 hours thereafter (before removal). Primary variable: change in average investigator-rated adhesiveness score between treatments, per modified European Medicines Agency scale (EMA/CHMP/QWP/911254/2011, 2012). RESULTS: Fifty-seven patients were randomized; 56 patients completed the study. Five patients were excluded from analysis for accidental unblinding. Treatment A had better average adhesiveness score (mean ± SD Treatment A - Treatment B: 1.115 ± 1.635). A higher percentage of patients on both days had patch adhesiveness ≥95% at 24 hours for Treatment A (first day: 65.4%, second day: 71.2%) vs. Treatment B (46.2%, 36.5%), and were satisfied with patch adhesiveness of Treatment A (first day: 75.0%, second day: 73.1%) vs. Treatment B (65.4%, 59.6%). Average patch-wear duration was similar between formulations (23.761 hours vs. 23.495 hours per patch). Both formulations were well tolerated with no new safety observations. CONCLUSION: Results indicated greater adhesiveness for the improved room temperature-stable formulation (PR2.3.1) vs. intermediate cold storage product (PR2.1.1) using the largest patch-size, with comparable safety and skin tolerability.

Efficacy of Epratuzumab, an Anti-CD22 Monoclonal IgG Antibody, in Systemic Lupus Erythematosus Patients With Associated Sjögren's Syndrome: Post Hoc Analyses From the EMBODY Trials.

OBJECTIVE: EMBODY 1 (ClinicalTrials.gov identifier: NCT01262365) and EMBODY 2 (ClinicalTrials.gov identifier: NCT01261793) investigated the efficacy and safety of epratuzumab, a CD22-targeted humanized monoclonal IgG antibody, in patients with systemic lupus erythematosus (SLE). The studies showed no significant difference from placebo in primary or secondary clinical outcome measures but did demonstrate B cell-specific immunologic activity. The aim of this post hoc analysis was to determine whether epratuzumab had a different clinical efficacy profile in SLE patients with versus those without an associated diagnosis of Sjögren's syndrome (SS). METHODS: The efficacy and safety of epratuzumab were compared between 2 patient subpopulations randomized in EMBODY 1 and 2: SLE patients with and those without a diagnosis of associated SS. British Isles Lupus Assessment Group (BILAG) total score, BILAG-based Combined Lupus Assessment (BICLA) clinical response to treatment, biologic markers (including B cells, IgG, IgM, and IgA), and safety were assessed. RESULTS: A total of 1,584 patients were randomized in the EMBODY 1 and EMBODY 2 trials; 113 patients were anti-SSA positive and had a diagnosis of associated SS, and 1,375 patients (86.8%) had no diagnosis of associated SS (918 patients were randomized to receive epratuzumab and 457 to receive placebo). For patients with associated SS, but not those without associated SS, a higher proportion of patients receiving epratuzumab achieved a BICLA response and a reduction from baseline in BILAG total score. B cell reduction was faster in patients with associated SS. The sensitivity of B cells to epratuzumab as measured by the mean concentration producing 50% of the maximum B cell count depletion was lower for patients with associated SS (9.5 µg/ml) versus the total EMBODY population (87.1 µg/ml). No difference in the frequency of adverse events in those receiving placebo was reported. CONCLUSION: Patients with SLE and associated SS treated with epratuzumab showed improvement in SLE disease activity, which was associated with bioactivity, such as decreases in B cell number and IgM level.

Pharmacokinetics of rotigotine transdermal system in adolescents with idiopathic restless legs syndrome (Willis-Ekbom disease).

OBJECTIVE: To investigate the pharmacokinetics (PK) of rotigotine transdermal system in adolescents with moderate-to-severe idiopathic restless legs syndrome (RLS). METHODS: This multicenter, open-label, dose-escalation study enrolled patients ≥13 to <18 years of age. Rotigotine transdermal patches were applied daily and up-titrated weekly: 0.5, 1, 2, 3 mg/24 h. Blood samples were collected on the final day of each dose step. Primary PK variables were the apparent total body clearance (CL/f; L/h) and volume of distribution at steady state (VSS/f; L) of unconjugated rotigotine for each dose step, calculated for the PK per-protocol set (PKPPS). Other PK, safety, and efficacy variables (International RLS Study Group Rating Scale [IRLS]; Clinical Global Impressions Item 1 [CGI-1]) were assessed. RESULTS: Of 24 patients who received rotigotine, 23 completed all dose steps and 17 formed the PKPPS. Least-squares mean (95% confidence interval) CL/f and VSS/f values were broadly similar across all dose steps (CL/f: 0.5 mg/24 h: 676.86 [408.50-1121.51]; 1 mg/24 h: 671.72 [459.11-982.80]; 2 mg/24 h: 937.56 [658.50-1334.89]; 3 mg/24 h: 1088.77 [723.47-1638.53]; VSS/f: 5403.16 [2850.67-10,241.17]; 6220.79 [3842.05-10,072.28]; 7114.01 [4547.88-11,128.07]; 6037.92 [3598.36-10,131.41]). Among 23 patients with efficacy data, mean IRLS and CGI-1 scores improved at each dosage level. Adverse events reported by ≥3 patients were nausea (seven) and application site reactions (four). CONCLUSIONS: Key PK properties of rotigotine in adolescent patients with moderate-to-severe idiopathic RLS were comparable to those previously observed in adults. Rotigotine improved RLS symptoms and was well tolerated. ClinicalTrials.gov: NCT01495793.

An open-label, multinational, multicenter study of G17DT vaccination combined with cisplatin and 5-fluorouracil in patients with untreated, advanced gastric or gastroesophageal cancer: the GC4 study.

BACKGROUND: Gastrin hormone is trophic to in vitro gastric cancer, and the antigastrin antibodies (AGAs) are antiproliferative and antimetastatic. Human gastric cancers overexpress gastrin genes and receptors that react to gastrin's trophic effects. Immunogen G17DT elicits a specific and high-affinity AGA. The authors evaluated G17DT vaccination given with cisplatin plus 5-fluorouracil for the treatment gastric adenocarcinoma. METHODS: In this multicenter, Phase II study, patients received G17DT vaccination intramuscularly on Weeks 1, 5, 9 and 25 and cisplatin plus 5-fluorouracil every 28 days. Eligible patients had untreated, metastatic, or unresectable gastric or gastroesophageal adenocarcinoma with near-normal organ function. The primary endpoint of the study was the over response rate (ORR), and secondary endpoints included overall survival (OS), safety, and the impact of successful vaccination on patient outcome. RESULTS: In total, 103 patients were enrolled in 5 countries. Seven patients who were overdosed inadvertently with 5-fluorouracil (a major protocol violation) were removed from the analysis. The confirmed ORR was 30% in 79 patients who were evaluated for response. The median time-to-progression (TTP) was 5.4 months, and the median survival (MS) was 9.0 months (n = 96 patients). Sixty-five of 94 patients who were vaccinated (69%) had 2 consecutive AGA titers of > or =1 units (successfully vaccinated patients or immune-responders). The TTP was longer in immune-responders than in immune-nonresponders (P = .0005). Similarly, the MS was longer in immune-responders than in immune-nonresponders (10.3 months vs. 3.8 months; P < or =.0001). In a multivariate analysis, successful vaccination was an independent OS prognosticator (P = .0001). G17DT did not have an adverse effect on safety. CONCLUSIONS: The results demonstrated that successful G17DT vaccination was correlated with longer TTP and MS. AGA response was an independent OS prognosticator. A Phase III evaluation of G17DT in gastric cancer is warranted.

The TRPV1 receptor: target of toxicants and therapeutics.

Understanding the structural and functional complexities of the transient receptor potential vanilloid receptor (TRPV1) is essential to the therapeutic modulation of inflammation and pain. Because of its central role in initiating inflammatory processes and integrating painful stimuli, there is an understandable interest in its pharmacological manipulation (sensitization/desensitization). The present Highlight entitled "TRPV1 antagonists elevate cell surface populations of receptor protein and exacerbate TRPV1 mediated toxicities in human lung epithelial cells" describes how exposure to various antagonists produces TRPV1 sensitization and proposes a possible mechanistic explanation to that sensitization.

Electrostatic charge activates inflammatory vanilloid (VR1) receptors.

The pathophysiology of neurogenic inflammation culminates in the overt symptoms of tissue inflammation through a series of events which are initiated by the activation of vanilloid receptors (VR1). This study was designed to test the hypothesis that a sufficiently negative, electrostatic charge carried on a particulate matter (PM) particle, could acquire a cloud of protons sufficient to activate proton-sensitive VR1 receptors and acid-sensitive ionic channels (ASICs) pathways. For this, nanometer-sized, synthetic polystyrene micells (SPM) or those charged with chemical groups (e.g. diamino, carboxyl) were used. These chemical groups imparted either a net positive (i.e. diamino) or negative (i.e. carboxyl) charge on the SPM when suspended in a neutral ionic medium. The zeta potential, a measure of the SPM's electronegativity, was taken in both cell culture nutrient medium and in ultraviolet light-distilled water (UV-DW). In both vehicles, the rank order of electronegativity (most to least negative) was carboxyl > polystyrene > diamino-SPM. Individual types of SPM were exposed to human, immortalized bronchial-tracheal epithelial cells (i.e. BEAS-2B) and endpoints of biological activation (i.e. membrane depolarization, increases in intracellular calcium (i.e. [Ca(2+)](i)) levels, IL-6 release) were measured. Cells loaded with a fluorescent probe for membrane depolarization (3,3'-dihexyloxacarbocyanine iodide, DiOC-6-3) showed a positive reaction when exposed to carboxyl-SPM but not to diamino-SPM. BEAS-2B cells exposed to carboxyl-SPM responded with significant increases in [Ca(2+)](i), and IL-6 release relative to uncharged SPM or diamino-SPM. This IL-6 release could be reduced by pretreatment with antagonists to the VR1 receptor (i.e. capsazepine) or to acid-sensitive ionc channels (i.e. amiloride). Although both diamino and carboxyl-SPM groups stimulated increases in IL-6 transcript, only the more electronegatively charged carboxyl-SPM stimulated mRNA-VR1 receptor. These data suggest that measurable inflammatory changes can be stimulated in human epithelial target cells by the electrostatic charge carried on an inert particle. Further, these changes appear to be mediated through acid-sensitive VR1 receptors and ASICs.

Particulate matter inflammation and receptor sensitivity are target cell specific.

The complexity of primary source particulate matter (PM) and the various cell types encountered by its inhalation raise the possibility that target cells are differentially activated. Since epithelial cells, which line the nasal-tracheal-bronchial airways, and sensory C fibers, which terminate throughout this epithelial layer, are initially targeted by inhaled PM, we compared their relative biological response in vitro to PM originating from volcanic (MSH), anthropogenic (diesel), residential (woodstove), urban ambient (St. Louis, Ottawa), and industrial emission (coal fly ash, CFA; residual oil fly ash, ROFA; oil fly ash, OFA) sources. Increases in intracellular calcium (i.e., [Ca(2+)](i)) are a second-messenger event that indicates cellular activation and signal transduction, in both nerve and epithelial cells. Single-cell calcium imaging recordings were taken of human bronchial epithelial cells (BEAS-2B) exposed to selected PM (50 microg/ml or 30 microg/cm(2)). These cells responded with variable increases in [Ca(2+)](i) ranging from abrupt increases, which returned to baseline upon washing of the cells, to oscillations of the [Ca(2+)](i) that did not wash out. Increases in [Ca(2+)](i) and inflammatory cytokine (i.e., interleukin 6, IL-6) release were measured in populations of BEAS-2B cells exposed to PM (50 microg/ml) and were shown to significantly correlate (r(2) =.80). BEAS-2B cells, stained histochemically with cobalt, displayed a concentration-dependent precipitation in response to acid pH and capsaicin, indicating the presence of acid-sensitive pathways (e.g., VR1 and acid-sensitive receptors). To demonstrate the relevance of these pathways to inflammatory cytokine (i.e., IL-6) release, BEAS-2B cells were pretreated (15 min) with antagonists to the vanilloid (VR1) receptor (i.e., capsazepine, CPZ) or acid-sensitive pathways (i.e., amiloride) before their exposure to the selected PM. A significant reduction of IL-6 release occurred in response to all PM, except for MSH and diesel exhaust. Dorsal root ganglia (DRG), which innervate the tracheal airways, were dissociated from fetal mice and pretreated with CPZ or amiloride before exposure (4 h) to the selected PM (50 microg/ml). Overall, significantly higher release occurred in PM-exposed sensory neurons relative to that of BEAS-2B epithelial cells. Although both CPZ and amiloride significantly reduced IL-6 release for all PM, the degree of inhibition was less for the PM-exposed DRG relative to BEAS-2B cells. These data show that differential increases in [Ca(2+)](i) and IL-6 release occur in BEAS-2B epithelial cells and DRG sensory neurons, when exposed to PM derived from different sources. The degree of this activation, however, depends not only on the source of the PM, but also on its cellular target. This differential sensitivity of target cells may contribute to the organism's overall inflammatory response to PM exposure.

The surface charge of visible particulate matter predicts biological activation in human bronchial epithelial cells.

The physicochemical complexity of airborne particulate matter (PM) has hampered identifying a specific mechanism(s) for its toxicity. In this study, selected physicochemical characteristics (i.e., size, particle number, acidity, and surface charge) were measured on various field PM, derived from urban ambient (St. Louis, Ottawa, Canada), residential (Woodstove), volcanic dust from Mt. St. Helen (MSH), and industrial [oil fly ash (OFA) coal fly ash (CFA)] sources. Morphometric analysis of visible (< or = 2.0 to >10 microm) field particles indicated that the industrial PM (OFA, CFA) had the smallest diameter and lowest total number of particles per weight while Woodstove and Ottawa had the largest diameter and highest number of particles. All PM lowered the pH of an unbuffered 10 mM NaCl solution from pH 7.4 to pH 4.7-6.8 but did not change the neutral pH of the cell culture medium, keratinocyte growth media (KGM). The surface charge (i.e., zeta potential) of microscopically visible (> or = 2.0 microm) field particles, suspended in either a Hepes-buffered KCl solution or in KGM, was measured by microelectrophoresis. In KCl solution, the mean zeta potential of all tested PM ranged from -36 +/- 2 (Woodstove) to -27 +/- 4.3 mV (MSH). When measured in KGM medium, the mean zeta potential value of each PM was significantly less (p > 0.001) than those measured in KCl solution, with values ranging from -17 +/- 0.3 mV (St. Louis) to -9 +/- 0.6 mV (MSH). Suspensions of field PM, its soluble and washed particulate fractions, were next prepared from each PM. The biological effects (i.e., increases in intracellular calcium ([Ca2+]i), cytokine release) of their exposure were measured in human, immortalized, tracheal-bronchial epithelial cells (BEAS-2B). Exposure of BEAS-2B cells to each fraction produced an immediate, but differential increase in [Ca2+]i and the subsequent release of the inflammatory cytokine IL-6, 4 and 16 h later. Increases in [Ca2+]i by field PM significantly correlated with the IL-6 released by each fraction (r2 > or = 0.76) after both 4 and 16 h exposures. The biological effects of each PM were compared with their physicochemical characteristics. No correlation was found between increases in [Ca2+]i or cytokine release and a PM's acidity or the number or size of its visible (> or = 2.0 microm) particles. However, the surface charge of PM field particles, when measured in the KGM exposure medium, showed a high correlation (r2 > or = 0.94) with the IL-6 release by field PM after both 4 and 16 h exposure. Increases in [Ca2+]i also correlated (r2 = 0.85) with the surface charge of PM field particles when measured in KGM. These data indicate that the surface charge (i.e., zeta potential) carried on PM's visible field particles predicts their differential release of the inflammatory cytokine IL-6 in cultures of human respiratory epithelial cells.