Drug Interactions for Low-Dose Inhaled Nemiralisib: A Case Study Integrating Modeling, In Vitro, and Clinical Investigations.

In vitro data for low-dose inhaled phosphoinositide 3-kinase delta inhibitor nemiralisib revealed that it was a substrate and a potent metabolism-dependent inhibitor of cytochrome P450 (P450) 3A4 and a P-glycoprotein (P-gp) substrate. An integrated in silico, in vitro, and clinical approach including a clinical drug interaction study as well as a bespoke physiologically based pharmacokinetic (PBPK) model was used to assess the drug-drug interaction (DDI) risk. Inhaled nemiralisib (100 µg, single dose) was coadministered with itraconazole, a potent P4503A4/P-gp inhibitor, following 200 mg daily administrations for 10 days in 20 male healthy subjects. Systemic exposure to nemiralisib (AUC0-inf) increased by 2.01-fold versus nemiralisib alone. To extrapolate the clinical data to other P4503A4 inhibitors, an inhaled PBPK model was developed using Simcyp software. Retrospective simulation of the victim risk showed good agreement between simulated and observed data (AUC0-inf ratio 2.3 vs. 2.01, respectively). Prospective DDI simulations predicted a weak but manageable drug interaction when nemiralisib was coadministered with other P4503A4 inhibitors, such as the macrolides clarithromycin and erythromycin (simulated AUC0-inf ratio of 1.7), both common comedications in the intended patient populations. PBPK and static mechanistic models were also used to predict a negligible perpetrator DDI effect for nemiralisib on other P4503A4 substrates, including midazolam (a sensitive probe substrate of P4503A4) and theophylline (a narrow therapeutic index drug and another common comedication). In summary, an integrated in silico, in vitro, and clinical approach including an inhalation PBPK model has successfully discharged any potential patient DDI risks in future nemiralisib clinical trials. SIGNIFICANCE STATEMENT: This paper describes the integration of in silico, in vitro, and clinical data to successfully discharge potential drug-drug interaction risks for a low-dose inhaled drug. This work featured assessment of victim and perpetrator risks of drug transporters and cytochrome P450 enzymes, utilizing empirical and mechanistic approaches combined with clinical data (drug interaction and human absorption, metabolism, and pharmacokinetics) and physiologically based pharmacokinetic modeling approaches to facilitate bespoke risk assessment in target patient populations.

Efficacy and safety of an anti-IL-13 mAb in patients with severe asthma: a randomized trial.

BACKGROUND: Approximately 5% to 10% of asthmatic patients achieve incomplete symptom control on current therapies. The association of IL-13 with asthma pathology and reduced corticosteroid sensitivity suggests a potential benefit of anti-IL-13 therapy in refractory asthma. GSK679586, a humanized mAb, inhibits IL-13 binding to both IL-13 receptor α1 and α2. OBJECTIVES: We sought to evaluate the efficacy and safety of GSK679586 in patients with severe asthma refractory to maximally indicated doses of inhaled corticosteroids. METHODS: Patients who remained symptomatic (Asthma Control Questionnaire score ≥1.5) after uptitration to 1000 µg/d fluticasone propionate or greater were randomized to 3 once-monthly intravenous infusions of 10 mg/kg GSK679586 (n = 99) or placebo (n = 99). RESULTS: Treatment differences in adjusted mean change from baseline over 12 weeks were nonsignificant for Asthma Control Questionnaire symptom scores (the primary end point; GSK679586 = -0.31, placebo = -0.17, P = .058) and FEV1 (GSK679586 = -0.01, placebo = 0.03, P = .276). Similar analyses in patients with increased serum IgE levels, blood eosinophil counts, or both were also negative. Incidence of asthma exacerbations was similar between treatments. Most adverse events were nonserious and unrelated to treatment. Two GSK679586-treated patients had treatment-related serious adverse events (lethargy and supraventricular extrasystoles). CONCLUSIONS: Although well tolerated, GSK679586 did not demonstrate clinically meaningful improvements in asthma control, pulmonary function, or exacerbations in patients with severe asthma. Further studies are needed to determine whether therapies targeting IL-13, the functionally related IL-4 cytokine, or both can provide clinical benefit in patients with severe refractory asthma or a subpopulation of these patients beyond that achievable with high-dose corticosteroids.

Treating idiopathic pulmonary fibrosis with the addition of co-trimoxazole: a randomised controlled trial.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal condition with limited treatment options. However, in a previous small study, co-trimoxazole was found to be beneficial. METHODS: In a double-blind multicentre study, 181 patients with fibrotic idiopathic interstitial pneumonia (89% diagnosed as definite/probable IPF) were randomised to receive co-trimoxazole 960 mg twice daily or placebo for 12 months in addition to usual care. Measurements were made of forced vital capacity (FVC) (primary endpoint), diffusing capacity of carbon monoxide (Dlco) and EuroQol (EQ5D)-based utility, 6-minute walk test (6MWT) and Medical Research Council (MRC) dyspnoea score (secondary endpoints). All-cause mortality and adverse events were recorded (tertiary endpoints). RESULTS: Co-trimoxazole had no effect on FVC (mean difference 15.5 ml (95% CI -93.6 to 124.6)), Dlco (mean difference -0.12 mmol/min/kPa (95% CI 0.41 to 0.17)), 6MWT or MRC dyspnoea score (intention-to-treat analysis). The findings of the per-protocol analysis were the same except that co-trimoxazole treatment resulted in a significant improvement in EQ5D-based utility (mean difference 0.12 (95% CI 0.01 to 0.22)), a reduction in the percentage of patients requiring an increase in oxygen therapy (OR 0.05 (95% CI 0.00 to 0.61)) and a significant reduction in all-cause mortality (co-trimoxazole 3/53, placebo 14/65, HR 0.21 (95% CI 0.06 to 0.78), p=0.02)) compared with placebo. The use of co-trimoxazole reduced respiratory tract infections but increased the incidence of nausea and rash. CONCLUSIONS: The addition of co-trimoxazole therapy to standard treatment for fibrotic idiopathic interstitial pneumonia had no effect on lung function but resulted in improved quality of life and a reduction in mortality in those adhering to treatment. ISRCTN22201583.

Thoracic Imaging at Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review.

Exacerbations of chronic obstructive pulmonary disease (COPD) are currently diagnosed based on changes in respiratory symptoms. Characterizing the imaging manifestation of exacerbations could be useful for objective diagnosis of exacerbations in the clinic and clinical trials, as well as provide a mechanism for monitoring exacerbation treatment and recovery. In this systematic review, we employed a comprehensive search across three databases (Medline, EMBASE, Web of Science) to identify studies that performed imaging of the thorax at COPD exacerbation. We included 51 from a total of 5,047 articles which met all our inclusion criteria. We used an adapted version of the Modified Newcastle-Ottawa Quality Assessment Scale for cohort studies to assess the quality of the included studies. Conclusions were weighted towards higher-quality articles. We identified a total of 36 thoracic imaging features studied at exacerbation of COPD. Studies were generally heterogeneous in their measurements and focus. Nevertheless, considering studies which performed consecutive imaging at stable state and exacerbation, which scored highest for quality, we identified salient imaging biomarkers of exacerbations. An exacerbation is characterized by airway wall and airway calibre changes, hyperinflation, pulmonary vasoconstriction and imaging features suggestive of pulmonary arterial hypertension. Most information was gained from CT studies. We present the first ever composite imaging signature of COPD exacerbations. While imaging during an exacerbation is comparatively new and not comprehensively studied, it may uncover important insights into the acute pathophysiologic changes in the cardiorespiratory system during exacerbations of COPD, providing objective confirmation of events and a biomarker of recovery and treatment response.

The Efficacy and Mechanism Evaluation of Treating Idiopathic Pulmonary fibrosis with the Addition of Co-trimoxazole (EME-TIPAC): study protocol for a randomised controlled trial.

BACKGROUND: We hypothesise, based upon the findings from our previous trial, that the addition of co-trimoxazole to standard therapy is beneficial to patients with moderate to severe idiopathic pulmonary fibrosis (IPF). We aim to investigate this by assessing unplanned hospitalisation-free survival (defined as time from randomisation to first non-elective hospitalisation, lung transplant or death) and to determine whether any effect relates to changes in infection and/or markers of disease control and neutrophil activity. METHODS/DESIGN: The EME-TIPAC trial is a double-blind, placebo-controlled, randomised, multicentre clinical trial. A total of 330 symptomatic patients, aged 40 years old or older, with IPF diagnosed by a multidisciplinary team (MDT) according to international guidelines and a FVC ≤ 75% predicted will be enrolled. Patients are randomised equally to receive either two tablets of co-trimoxazole 480 mg or two placebo tablets twice daily over a median treatment period of 27 (range 12-42) months. All patients receive folic acid 5 mg daily whilst on the trial IMP to reduce the risk of bone marrow depression. The primary outcome for the trial is a composite endpoint consisting of the time to death, transplant or first non-elective hospital admission and will be determined from adverse event reporting, hospital databases and the Office of National Statistics with active tracing of patients missing appointments. Secondary outcomes include the individual components of the primary outcome, (1) King's Brief Interstitial Lung Disease Questionnaire, (2) MRC Dyspnoea Score, (3) EQ5D, (4) spirometry, (5) total lung-diffusing capacity and (6) routine sputum microbiology. Blood will be taken for cell count, biochemistry and analysis of biomarkers including C-reactive protein and markers of disease. The trial will last for 4 years. Recruitment will take place in a network of approximately 40 sites throughout the UK (see Table 1 for a full list of participating sites). We expect recruitment for 30 months, follow-up for 12 months and trial analysis and reporting to take 4 months. DISCUSSION: The trial is designed to test the hypothesis that treating IPF patients with co-trimoxazole will increase the time to death (all causes), lung transplant or first non-elective hospital admission compared to standard care ( https://www.nice.org.uk/guidance/cg163 ), in patients with moderate to severe disease. The mechanistic aims are to investigate the effect on lung microbiota and other measures of infection, markers of epithelial injury and markers of neutrophil activity. TRIAL REGISTRATION: International Standard Randomised Controlled Trials Number (ISRCTN) Registry, ID: 17464641 . Registered on 29 January 2015.

Modulation of p-glycoprotein and breast cancer resistance protein by some prescribed corticosteroids.

Efflux transporters, p-glycoprotein and breast cancer resistance protein (BCRP), located at barrier sites such as the blood-brain barrier may affect distribution of steroids used for treating chronic inflammatory conditions and thus the extent to which they may perturb the hypothalamic-pituitary-adrenal axis. In the present study, six different glucocorticoids were investigated for their possible interactions with these efflux transporters. Beclomethasone dipropionate, mometasone furoate and ciclesonide active principle but not fluticasone propionate or triamcinolone, (all at 0.1 to 10 microM) caused inhibition of efflux, resulting in increased accumulation of mitoxantrone in BCRP-expressing MCF7/MR breast cancer cells and of calcein in p-glycoprotein-expressing SW620/R colon carcinoma cell. At 5 microM the same three increased sensitivity of p-glycoprotein-expressing SW620/R to doxorubicin and stimulated ATPase activity associated with BCRP expressed in bacterial membrane vesicles. Budesonide also stimulated ATPase activity. These data demonstrate the capacity of some clinically used glucocorticoids to interact with efflux transporters.

Treating idiopathic pulmonary fibrosis with the addition of co-trimoxazole: an economic evaluation alongside a randomised controlled trial.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fibrotic disease of the lungs of unknown origin with a poor prognosis. A small trial of co-trimoxazole demonstrated improvements in symptoms and functional parameters over a 3-month period. We therefore conducted a larger trial with a concurrent economic evaluation to investigate this antibiotic further. METHODS: We report an economic evaluation alongside a multi-centre, randomised, placebo-controlled, double-blind trial of 12 months therapy with 960 mg co-trimoxazole daily in 181 patients with fibrotic idiopathic interstitial pneumonia (IIP). Patients were recruited from 28 university and district hospitals in the UK and were aged over 40 years with fibrotic IIP. We report costs to the National Health Service (NHS) and society, change in forced vital capacity (primary endpoint) and quality-adjusted life-years (QALYs) gained, incremental cost effectiveness and cost utility ratios over 12 months. RESULTS: From the perspective of society, mean cost per patient in the co-trimoxazole arm was approximately £1177 higher than in the placebo arm, but mean QALYs were 0.053 higher yielding an incremental cost-effectiveness ratio of £22,012 per QALY gained with a 54.44 % probability of being below £30,000. The cost of IPF to UK society in 2011 is tentatively estimated at £124 million, of which 13 % is NHS costs, 1 % social services, 2 % patient out-of-pocket costs and 84 % lost productivity. CONCLUSIONS: Given commonly employed thresholds in the UK NHS, on balance co-trimoxazole may be a cost-effective treatment for IPF, although there is substantial decision uncertainty. However, recent guidance on the use of immunosuppressive therapy in IPF patients should be taken into account prior to any policy decision.