A Bayesian method for safety signal detection in ongoing blinded randomised controlled trials.

Sponsors have a responsibility to minimise risk to participants in clinical studies through safety monitoring. The FDA Final Rule for IND Safety Reporting requires routine aggregate safety evaluation, including in ongoing blinded studies. We are interested in estimating the probability that the true adverse event rate in the experimental arm exceeds that in the control arm. We developed a Bayesian approach that specifies an informative meta-analytic predictive prior on the event probability in the control arm and an uninformative prior on that in the experimental arm. We combined these priors with a mixture likelihood that considers each patient in the ongoing blinded study may belong to the experimental or control arm. This allowed us to estimate the quantity of interest without unblinding. We evaluated our method by simulation, pairing scenarios that differed only in whether a safety signal was present or missing, and quantifying the ability of our model to discriminate using signal detection theory. Our approach shows benefit. It detects safety signals more reliably with greater sample sizes and for common rather than rare events. Performance does not deteriorate markedly when historical studies exhibit heterogeneous hazards or non-constant hazards. Our method will allow us to monitor safety signals in ongoing blinded studies with the goal of earlier identification and risk mitigation. Our method could be adapted to use informative priors on both arms or predictive covariates where pertinent data exist. We stress that ongoing safety monitoring should involve a multi-disciplinary team where statistical methods are paired with medical judgement.

Randomized dose-finding study of batefenterol via dry powder inhaler in patients with COPD.

BACKGROUND: Batefenterol is a novel bifunctional muscarinic antagonist ß2-agonist in development for COPD. The primary objective of this randomized, double-blind, placebo-controlled, active comparator, Phase IIb study was to model the dose-response of batefenterol and select a dose for Phase III development. PATIENTS AND METHODS: Patients aged ≥40 years with COPD and FEV1 ≥30% and ≤70% predicted normal were randomized equally to batefenterol 37.5, 75, 150, 300, or 600 µg, placebo, or umeclidinium/vilanterol (UMEC/VI) 62.5/25 µg once daily. The primary and secondary endpoints were weighted-mean FEV1 over 0-6 hours post-dose and trough FEV1, analyzed by Bayesian and maximum likelihood estimation Emax of dose-response modeling, respectively, on day 42. RESULTS: In the intent-to-treat population (N=323), all batefenterol doses demonstrated statistically and clinically significant improvements from baseline vs placebo in the primary and secondary endpoints (191.1-292.8 and 182.2-244.8 mL, respectively), with a relatively flat dose-response. In the subgroup reversible to salbutamol, there were greater differences between batefenterol doses. Lung function improvements with batefenterol ≥150 µg were comparable with those with UMEC/VI. Batefenterol was well tolerated and no new safety signals were observed. CONCLUSION: Batefenterol 300 µg may represent the optimal dose for Phase III studies.

Addition of a 5-lipoxygenase-activating protein inhibitor to an inhaled corticosteroid (ICS) or an ICS/long-acting beta-2-agonist combination in subjects with asthma.

OBJECTIVE: To investigate the clinical benefits of 'add-on' therapy with GSK2190915 in combination with the inhaled corticosteroid (ICS) fluticasone propionate (FP) and the ICS/long-acting beta 2 agonist (LABA) combination FP/salmeterol in asthmatic subjects. METHODS: Both studies were cross-over, randomized, double-blind, double-dummy and placebo-controlled in subjects with a forced expiratory volume in 1 second (FEV1) best of >50 and ≤80% of predicted. Add-on to ICS: Subjects (n = 162) aged ≥12 years received FP 100 µg twice daily (BID) plus GSK2190915 100 mg once daily (QD); GSK2190915 300 mg QD; montelukast 10 mg QD; salmeterol 50 µg BID or placebo. Add-on to ICS/LABA: Female subjects (n = 145) aged ≥18 years received FP/salmeterol 250/50 µg BID plus GSK2190915 300 mg QD, montelukast 10 mg QD or placebo. In both studies, the primary endpoint was trough FEV1 at the end of the treatment period. Secondary endpoints included a range of objective and patient-reported measures of efficacy. RESULTS: Add-on to ICS: There was no statistically significant difference in the primary endpoint between either dose of GSK2190915 (add-on to FP) and placebo. Nominally statistically significant increases were demonstrated for GSK2190915 300 mg add-on relative to placebo for mean morning peak expiratory flow (p = 0.049), percentage of symptom-free days (p = 0.035) and percentage of symptom-free 24 h periods (p = 0.030). Add-on to ICS/LABA: There were no statistically significant differences on the primary endpoint between treatment regimens. Nominally statistically significant decreases were demonstrated in daytime (p = 0.023), night-time (p = 0.041) and 24 h (p = 0.019) short-acting beta 2 agonist usage with FP/salmeterol + GSK2190915 300 mg vs. FP/salmeterol + placebo. CONCLUSION: There was no clinically significant improvement in the primary endpoint following GSK2190915 add-on treatment; however, improvements in a range of secondary endpoints and biomarker data provided evidence of pharmacological activity. Improvements in response to background treatment may have been a limitation in both studies. TRIAL REGISTRATION: Clinicaltrials.gov identifiers: NCT01156792 and NCT01248975.

Efficacy, safety and tolerability of GSK2190915, a 5-lipoxygenase activating protein inhibitor, in adults and adolescents with persistent asthma: a randomised dose-ranging study.

BACKGROUND: GSK2190915 is a high affinity 5-lipoxygenase-activating protein inhibitor being developed for the treatment of asthma. The objective of this study was to evaluate GSK2190915 efficacy, dose-response and safety in subjects with persistent asthma treated with short-acting beta2-agonists (SABAs) only. METHODS: Eight-week multicentre, randomised, double-blind, double-dummy, stratified (by age and smoking status), parallel-group, placebo-controlled study in subjects aged ≥12 years with a forced expiratory volume in 1 second (FEV1) of 50-85% predicted. Subjects (n = 700) were randomised to receive once-daily (QD) oral GSK2190915 (10-300 mg), twice-daily inhaled fluticasone propionate 100 µg, oral montelukast 10 mg QD or placebo. The primary endpoint was mean change from baseline (randomisation) in trough (morning pre-dose and pre-rescue bronchodilator) FEV1 at the end of the 8-week treatment period. Secondary endpoints included morning and evening peak expiratory flow, symptom-free days and nights, rescue-free days and nights, day and night-time symptom scores, day and night-time rescue medication use, withdrawals due to lack of efficacy, Asthma Control Questionnaire and Asthma Quality of Life Questionnaire scores. RESULTS: For the primary endpoint, there was no statistically significant difference between any dose of GSK2190915 QD and placebo. However, repeated measures sensitivity analysis demonstrated nominal statistical significance for GSK2190915 30 mg QD compared with placebo (mean difference: 0.115 L [95% confidence interval: 0.00, 0.23], p = 0.044); no nominally statistically significant differences were observed with any of the other doses. For the secondary endpoints, decreases were observed in day-time symptom scores and day-time SABA use for GSK2190915 30 mg QD versus placebo (p ≤ 0.05). No dose-response relationship was observed for the primary and secondary endpoints across the GSK2190915 dose range studied; the 10 mg dose appeared to be sub-optimal. GSK2190915 was associated with a dose-dependent reduction in urinary leukotriene E4. The profile and incidence of adverse events were similar between treatment groups. CONCLUSION: Efficacy was demonstrated for GSK2190915 30 mg compared with placebo in day-time symptom scores and day-time SABA use. No additional improvement on efficacy endpoints was gained by administration of GSK2190915 doses greater than 30 mg. GSK2190915 was well-tolerated. These results may support further studies with GSK2190915 30 mg. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01147744.

Effects of fluticasone propionate and salmeterol hydrofluoroalkane inhalation aerosol on asthma-related quality of life.

BACKGROUND: Current asthma guidelines emphasize domains of impairment and risk for assessing severity and control, noting the need to consider separately the effects of asthma on asthma quality of life and functional capacity. Proper treatment to control asthma should result in improvements in patient well-being and functional status. OBJECTIVE: To assess asthma-related quality of life after treatment with combination fluticasone propionate and salmeterol delivered via hydrofluoroalkane 134a metered-dose inhaler compared with the individual components alone. METHODS: Asthma-related quality of life was assessed as part of two 12-week, randomized, double-blind, placebo-controlled clinical trials comparing the fluticasone propionate-salmeterol combination administered via a single metered-dose inhaler with salmeterol, fluticasone propionate, and placebo administered via traditional chlorofluorocarbon metered-dose inhaler. The Asthma Quality of Life Questionnaire was completed at baseline and end point. Score changes, overall and for the 4 separate domains, were compared within and among the treatment groups. RESULTS: A total of 720 of 725 patients completed a baseline Asthma Quality of Life Questionnaire and were included in the analyses. In both studies, all mean scores improved significantly from baseline with the fluticasone propionate-salmeterol combination, with significantly greater improvement in the overall score compared with salmeterol alone, fluticasone propionate alone, and placebo groups. Improvements with the combination were also clinically meaningful compared with changes with salmeterol and placebo in both studies and with fluticasone propionate in study 1. CONCLUSIONS: Treatment with combination fluticasone propionate and salmeterol delivered via hydrofluoroalkane metered-dose inhaler resulted in significantly greater improvements in asthma-related quality of life compared with individual components and placebo administered via traditional chlorofluorocarbon metered-dose inhaler.

Efficacy and safety of fluticasone propionate/salmeterol HFA 134A MDI in patients with mild-to-moderate persistent asthma.

The objective of this study was to compare the efficacy and safety of fluticasone propionate (FP) (44 microg)/salmeterol (21 microg) delivered as two inhalations twice daily via a single hydrofluoroalkane (HFA 134a) metered dose inhaler (MDI) (FSC) with that of placebo HFA 134a (PLA), fluticasone propionate 44 microg chlorofluorocarbon (CFC) alone and salmeterol 21 microg CFC alone (S) in patients (n=360) with persistent asthma previously treated with beta2-agonists (short- or long-acting) or inhaled corticosteroids (ICS). After 12 weeks of treatment, patients treated with FSC had a significantly greater increase (p < or = 0.006) in mean FEV1 AUC(bl) compared with PLA, FP, or S. At end point, mean change from baseline in morning predose FEV1 for FSC (0.58 L) was significantly (p < or = 0.004) greater than PLA (0.14 L), FP (0.36 L), and S (0.25 L). Patients treated with FSC also had a significantly higher probability of remaining in the study without being withdrawn due to worsening asthma (2%) compared with those in the PLA (29%) and S (25%) groups (p < 0.001). Finally, treatment with FSC resulted in significantly (p < or = 0.007) greater improvements in morning and evening peak expiratory flow, need for rescue albuterol, and asthma symptom scores compared with FP, S, and PLA. The safety profile of FSC was also similar to FP or S alone. Initial maintenance treatment of the two main components of asthma, inflammation, and smooth muscle dysfunction (e.g., bronchoconstriction), with FSC results in greater overall improvements in asthma control compared with treatment of either individual component alone.