Pharmacokinetics and safety of inhaled oxytocin compared with intramuscular oxytocin in women in the third stage of labour: A randomized open-label study.

AIMS: To compare pharmacokinetics (PK) and safety of heat-stable inhaled (IH) oxytocin with intramuscular (IM) oxytocin in women in third stage of labour (TSL), the primary endpoint being PK profiles of oxytocin IH and secondary endpoint of safety. METHODS: A phase 1, randomized, cross-over study was undertaken in 2 UK and 1 Australian centres. Subjects were recruited into 2 groups: Group 1, women in TSL; Group 2, nonpregnant women of childbearing potential (Cohort A, combined oral contraception; Cohort B, nonhormonal contraception). Participants were randomized 1:1 to: Group 1, oxytocin 10 IU (17 µg) IM or oxytocin 240 IU (400 µg) IH immediately after delivery; Group 2, oxytocin 5 IU (8.5 µg) intravenously and oxytocin 240 IU (400 µg) IH at 2 separate dosing sessions. RESULTS: Participants were recruited between 23 November 2016 to 4 March 2019. In Group 1, 17 participants were randomized; received either IH (n = 9) or IM (n = 8) oxytocin. After IH and IM administration, most plasma oxytocin concentrations were below quantification limits (2 pg/mL). In Group 2 (n = 14), oxytocin IH concentrations remained quantifiable ≤3 h postdose. Adverse events were reported in both groups, with no deaths reported: Group 1, IH n = 3 (33%) and IM n = 2 (25%); Group 2, n = 14 (100%). CONCLUSION: Safety profiles of oxytocin IH and IM were similar. However, PK profiles could not be established for oxytocin IH or IM in women in TSL, despite using a highly sensitive and specific assay.

Exploring the role of ex vivo metabolism on blood and plasma measurements of oxytocin among women in the third stage of labour: A post hoc study.

AIMS: To examine the role of ex vivo oxytocin metabolism in post-dose peptide measurements. METHODS: The stability of oxytocin (Study 1) and oxytocinase activity (Study 2) in late-stage pregnancy blood was quantified using liquid-chromatography tandem mass-spectrometry (LC-MS/MS) and a fluorogenic assay, respectively. Analyses were conducted using blood from pregnant women (>36 weeks gestation) evaluated in lithium heparin (LH), ethylenediaminetetraacetic acid (EDTA) and BD P100 blood collection tubes with or without protease inhibitors. In addition, plasma oxytocin concentrations following administration of oxytocin 240 IU inhaled, 5 IU intravenous or 10 IU intramuscular in women in third stage of labour (TSL) were analysed using enzyme-linked immunosorbent assay (ELISA) and LC-MS/MS to understand how quantified peptide concentrations differ between these analytical methods (Study 3). RESULTS: Study 1: Oxytocin was stable in blood collected into EDTA tubes with or without protease inhibitors but not in LH tubes. Study 2: Blood collected into all EDTA-containing collection tubes led to near-complete inhibition of oxytocinase (≤100 min). In plasma, a 35% reduction in oxytocinase activity was observed in LH tubes with EDTA added. In plasma from late-stage pregnancy compared to nonpregnant participants, the oxytocinase activity was approximately 11-fold higher. Study 3: Plasma oxytocin concentrations from nonpregnant or women in TSL following exogenous oxytocin administration were ≤33 times higher when analysed using ELISA vs. LC-MS/MS methods. CONCLUSIONS: Collection of blood from late-stage pregnant women into tubes containing EDTA inhibits oxytocinase effectively stabilizing oxytocin, suggesting low concentrations of oxytocin after dose administration reflect rapid in vivo metabolism.

Longitudinal Lung Function Assessment of Patients Hospitalized With COVID-19 Using 1H and 129Xe Lung MRI.

BACKGROUND: Microvascular abnormalities and impaired gas transfer have been observed in patients with COVID-19. The progression of pulmonary changes in these patients remains unclear. RESEARCH QUESTION: Do patients hospitalized with COVID-19 without evidence of architectural distortion on structural imaging exhibit longitudinal improvements in lung function measured by using 1H and 129Xe MRI between 6 and 52 weeks following hospitalization? STUDY DESIGN AND METHODS: Patients who were hospitalized with COVID-19 pneumonia underwent a pulmonary 1H and 129Xe MRI protocol at 6, 12, 25, and 51 weeks following hospital admission in a prospective cohort study between November 2020 and February 2022. The imaging protocol was as follows: 1H ultra-short echo time, contrast-enhanced lung perfusion, 129Xe ventilation, 129Xe diffusion-weighted, and 129Xe spectroscopic imaging of gas exchange. RESULTS: Nine patients were recruited (age 57 ± 14 [median ± interquartile range] years; six of nine patients were male). Patients underwent MRI at 6 (n = 9), 12 (n = 9), 25 (n = 6), and 51 (n = 8) weeks following hospital admission. Patients with signs of interstitial lung damage were excluded. At 6 weeks, patients exhibited impaired 129Xe gas transfer (RBC to membrane fraction), but lung microstructure was not increased (apparent diffusion coefficient and mean acinar airway dimensions). Minor ventilation abnormalities present in four patients were largely resolved in the 6- to 25-week period. At 12 weeks, all patients with lung perfusion data (n = 6) showed an increase in both pulmonary blood volume and flow compared with 6 weeks, although this was not statistically significant. At 12 weeks, significant improvements in 129Xe gas transfer were observed compared with 6-week examinations; however, 129Xe gas transfer remained abnormally low at weeks 12, 25, and 51. INTERPRETATION: 129Xe gas transfer was impaired up to 1 year following hospitalization in patients who were hospitalized with COVID-19 pneumonia, without evidence of architectural distortion on structural imaging, whereas lung ventilation was normal at 52 weeks.

An open label trial of nemiralisib, an inhaled PI3 kinase delta inhibitor for the treatment of Activated PI3 kinase Delta Syndrome.

Activated PI3Kδ Syndrome (APDS) is a rare inherited inborn error of immunity caused by mutations that constitutively activate the p110 delta isoform of phosphoinositide 3-kinase (PI3Kδ), resulting in recurring pulmonary infections. Currently no licensed therapies are available. Here we report the results of an open-label trial in which five subjects were treated for 12 weeks with nemiralisib, an inhaled inhibitor of PI3Kδ, to determine safety, systemic exposure, together with lung and systemic biomarker profiles (Clinicaltrial.gov: NCT02593539). Induced sputum was captured to measure changes in phospholipids and inflammatory mediators, and blood samples were collected to assess pharmacokinetics of nemiralisib, and systemic biomarkers. Nemiralisib was shown to have an acceptable safety and tolerability profile, with cough being the most common adverse event, and no severe adverse events reported during the study. No meaningful changes in phosphatidylinositol (3,4,5)-trisphosphate (PIP3; the enzyme product of PI3Kδ) or downstream inflammatory markers in induced sputum, were observed following nemiralisib treatment. Similarly, there were no meaningful changes in blood inflammatory markers, or lymphocytes subsets. Systemic levels of nemiralisib were higher in subjects in this study compared to previous observations. While nemiralisib had an acceptable safety profile, there was no convincing evidence of target engagement in the lung following inhaled dosing and no downstream effects observed in either the lung or blood compartments. We speculate that this could be explained by nemiralisib not being retained in the lung for sufficient duration, suggested by the increased systemic exposure, perhaps due to pre-existing structural lung damage. In this study investigating a small number of subjects with APDS, nemiralisib appeared to be safe and well-tolerated. However, data from this study do not support the hypothesis that inhaled treatment with nemiralisib would benefit patients with APDS.

A randomised trial of anti-GM-CSF otilimab in severe COVID-19 pneumonia (OSCAR).

BACKGROUND: Granulocyte-macrophage colony-stimulating factor (GM-CSF) and dysregulated myeloid cell responses are implicated in the pathophysiology and severity of COVID-19. METHODS: In this randomised, sequential, multicentre, placebo-controlled, double-blind study, adults aged 18-79 years (Part 1) or ≥70 years (Part 2) with severe COVID-19, respiratory failure and systemic inflammation (elevated C-reactive protein/ferritin) received a single intravenous infusion of otilimab 90 mg (human anti-GM-CSF monoclonal antibody) plus standard care (NCT04376684). The primary outcome was the proportion of patients alive and free of respiratory failure at Day 28. RESULTS: In Part 1 (n=806 randomised 1:1 otilimab:placebo), 71% of otilimab-treated patients were alive and free of respiratory failure at Day 28 versus 67% who received placebo; the model-adjusted difference of 5.3% was not statistically significant (95% CI -0.8-11.4%, p=0.09). A nominally significant model-adjusted difference of 19.1% (95% CI 5.2-33.1%, p=0.009) was observed in the predefined 70-79 years subgroup, but this was not confirmed in Part 2 (n=350 randomised) where the model-adjusted difference was 0.9% (95% CI -9.3-11.2%, p=0.86). Compared with placebo, otilimab resulted in lower serum concentrations of key inflammatory markers, including the putative pharmacodynamic biomarker CC chemokine ligand 17, indicative of GM-CSF pathway blockade. Adverse events were comparable between groups and consistent with severe COVID-19. CONCLUSIONS: There was no significant difference in the proportion of patients alive and free of respiratory failure at Day 28. However, despite the lack of clinical benefit, a reduction in inflammatory markers was observed with otilimab, in addition to an acceptable safety profile.

Mass spectrometry detection of inhaled drug in distal fibrotic lung.

BACKGROUND: Currently the only available therapies for fibrotic Interstitial Lung Disease are administered systemically, often causing significant side effects. Inhaled therapy could avoid these but to date there is no evidence that drug can be effectively delivered to distal, fibrosed lung. We set out to combine mass spectrometry and histopathology with rapid sample acquisition using transbronchial cryobiopsy to determine whether an inhaled drug can be delivered to fibrotic, distal lung parenchyma in participants with Interstitial Lung Disease. METHODS: Patients with radiologically and multidisciplinary team confirmed fibrotic Interstitial Lung Disease were eligible for this study. Transbronchial cryobiopsies and endobronchial biopsies were taken from five participants, with Interstitial Lung Disease, within 70 min of administration of a single dose of nebulised ipratropium bromide. Thin tissue cryosections were analysed by Matrix Assisted Laser Desorption/Ionization-Mass Spectrometry imaging and correlated with histopathology. The remainder of the cryobiopsies were homogenised and analysed by Liquid Chromatography-tandem Mass Spectrometry. RESULTS: Drug was detected in proximal and distal lung samples from all participants. Fibrotic regions were identified in research samples of four of the five participants. Matrix Assisted Laser Desorption/Ionization-Mass Spectrometry imaging showed co-location of ipratropium with fibrotic regions in samples from three participants. CONCLUSIONS: In this proof of concept study, using mass spectrometry, we demonstrate for the first-time that an inhaled drug can deposit in distal fibrotic lung parenchyma in patients with Interstitial Lung Disease. This suggests that drugs to treat pulmonary fibrosis could potentially be administered by the inhaled route. Trial registration A prospective clinical study approved by London Camden and Kings Cross Research Ethics Committee and registered on clinicaltrials.gov (NCT03136120).

An open-label, dose-escalation study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single doses of GSK2586881 in participants with pulmonary arterial hypertension.

Preclinical and early clinical studies suggest that angiotensin-converting enzyme type 2 activity may be impaired in patients with pulmonary arterial hypertension (PAH); therefore, administration of exogenous angiotensin-converting enzyme type 2 (ACE2) may be beneficial. This Phase IIa, multi-center, open-label, exploratory, single-dose, dose-escalation study (NCT03177603) assessed the potential vasodilatory effects of single doses of GSK2586881 (a recombinant human ACE2) on acute cardiopulmonary hemodynamics in hemodynamically stable adults with documented PAH who were receiving background PAH therapy. Successive cohorts of participants were administered a single intravenous dose of GSK2586881 of 0.1, 0.2, 0.4, or 0.8 mg/kg. Dose escalation occurred after four or more participants per cohort were dosed and a review of safety, tolerability, pharmacokinetics, and hemodynamic data up to 24 h postdose was undertaken. The primary endpoint was a change in cardiopulmonary hemodynamics (pulmonary vascular resistance, cardiac index, and mean pulmonary artery pressure) from baseline. Secondary/exploratory objectives included safety and tolerability, effect on renin-angiotensin system peptides, and pharmacokinetics. GSK2586881 demonstrated no consistent or sustained effect on acute cardiopulmonary hemodynamics in participants with PAH receiving background PAH therapy (N = 23). All doses of GSK2586881 were well tolerated. GSK2586881 was quantifiable in plasma for up to 4 h poststart of infusion in all participants and caused a consistent and sustained reduction in angiotensin II and a corresponding increase in angiotensin (1-7) and angiotensin (1-5). While there does not appear to be a consistent acute vasodilatory response to single doses of GSK2586881 in participants with PAH, the potential benefits in terms of chronic vascular remodeling remain to be determined.

A Phase 1 study of the long-acting anti-IL-5 monoclonal antibody GSK3511294 in patients with asthma.

AIMS: GSK3511294 is a humanized anti-interleukin (IL)-5 monoclonal antibody (mAb) engineered for extended half-life and improved IL-5 affinity versus other anti-IL-5 mAbs. This study examined its safety, tolerability, pharmacokinetics (PK) and effect on blood eosinophil counts. METHODS: This was a double-blind, parallel-group, single-ascending-dose, multicenter, Phase 1 study (205 722;NCT03287310) in patients with asthma and a blood eosinophil count ≥200 cells µL-1 . Patients were randomized 3:1 within dose cohorts to receive a single subcutaneous dose of GSK3511294 (2, 10, 30, 100 or 300 mg) or placebo and followed for up to 40 weeks to assess safety (primary endpoint), ratio to baseline in blood eosinophil count, plasma PK parameters and frequency/titers of binding antidrug antibodies (all secondary). RESULTS: Forty-eight patients received the study drug and completed the study. Adverse events (AEs) occurred in 92% of placebo-treated and 81% of GSK3511294-treated patients. There were no AEs leading to study withdrawal or serious AEs; hypersensitivity (one event in one patient) and injection-site reaction (three events in two patients) occurred infrequently. Marked reductions (>48%) in blood eosinophil count were seen from 24 hours post-dose with all GSK3511294 doses but not placebo; suppression was maintained for longer with increasing dose (82% and 83% adjusted reductions vs placebo with 100 and 300 mg, respectively, at week 26). PK were linear and dose proportional over the dose range; terminal half-life was 38-53 days. CONCLUSIONS: GSK3511294 was well tolerated, with linear and dose proportional PK, extended half-life and blood eosinophil count reduction, supporting less frequent dosing versus other anti-IL-5 mAbs.

Effects of Recombinant Human Angiotensin-Converting Enzyme 2 on Response to Acute Hypoxia and Exercise: A Randomised, Placebo-Controlled Study.

INTRODUCTION: Angiotensin-converting enzyme 2 (ACE2) is a key enzyme of the renin-angiotensin system (RAS) that has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS). Enhancing ACE2 activity using GSK2586881, a recombinant form of human ACE2, could be beneficial in diseases such as ARDS but may blunt the hypoxic pulmonary vasoconstriction (HPV) response and potentially impact systemic and tissue oxygenation. This study aimed to evaluate the effect of GSK2586881 0.8 mg/kg on HPV response in healthy adult volunteers during exercise under hypoxic conditions. METHODS: In this phase I, randomised, double-blind (sponsor open) study, GSK2586881 or placebo was administered as a single intravenous (IV) dose in a two-period crossover design. Treatment periods were separated by a washout period of 3-14 days. The primary endpoint was change from baseline in pulmonary artery systolic pressure (PASP) measured by echocardiography. Secondary endpoints included RAS peptides and oxygen saturation. RESULTS: Seventeen adults aged 18-40 years were randomised to treatment. There were no clinically relevant differences (defined as a reduction of ≥ 5 mmHg) in change from baseline in PASP between GSK2586881 and placebo. GSK2586881 was well tolerated, with no serious adverse events, no worsening of hypoxaemia and no evidence of immunogenicity. The study was terminated early after review of the data, which showed that the predefined success criteria had not been met. Following GSK2586881 administration, levels of the RAS peptide angiotensin II decreased while angiotensin (1-7) increased, as expected, indicating that GSK2586881 was pharmacologically active. CONCLUSIONS: A single IV dose of GSK2586881 0.8 mg/kg was well tolerated but did not impact the acute HPV response in healthy volunteers.

An Inhaled PI3Kδ Inhibitor Improves Recovery in Acutely Exacerbating COPD Patients: A Randomized Trial.

Purpose: This study evaluated the safety and efficacy of inhaled nemiralisib, a phosphoinositide 3-kinase δ (PI3Kδ) inhibitor, in patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD). Methods: In this double-blind, placebo-controlled study, 126 patients (40-80 years with a post-bronchodilator forced expiratory volume in 1 sec (FEV1) ≤80% of predicted (previously documented)) were randomized 1:1 to once daily inhaled nemiralisib (1 mg) or placebo for 84 days, added to standard of care. The primary endpoint was specific imaging airway volume (siVaw) after 28 treatment days and was analyzed using a Bayesian repeated measures model (clintrials.gov: NCT02294734). Results: A total of 126 patients were randomized to treatment; 55 on active treatment and 49 on placebo completed the study. When comparing nemiralisib and placebo-treated patients, an 18% placebo-corrected increase from baseline in distal siVaw (95% credible intervals (Cr I) (-1%, 42%)) was observed on Day 28. The probability that the true treatment ratio was >0% (Pr(θ>0)) was 96%, suggestive of a real treatment effect. Improvements were observed across all lung lobes. Patients treated with nemiralisib experienced a 107.3 mL improvement in posterior median FEV1 (change from baseline, 95% Cr I (-2.1, 215.5)) at day 84, compared with placebo. Adverse events were reported by 41 patients on placebo and 49 on nemiralisib, the most common being post-inhalation cough on nemiralisib (35%) vs placebo (3%). Conclusion: These data show that addition of nemiralisib to usual care delivers more effective recovery from an acute exacerbation and improves lung function parameters including siVaw and FEV1. Although post-inhalation cough was identified, nemiralisib was otherwise well tolerated, providing a promising novel therapy for this acutely ill patient group.

Exploring PI3Kδ Molecular Pathways in Stable COPD and Following an Acute Exacerbation, Two Randomized Controlled Trials.

Background: Inhibition of phosphoinositide 3-kinase δ (PI3Kδ) exerts corrective effects on the dysregulated migration characteristics of neutrophils isolated from patients with chronic obstructive pulmonary disease (COPD). Objective: To develop novel, induced sputum endpoints to demonstrate changes in neutrophil phenotype in the lung by administering nemiralisib, a potent and selective inhaled PI3Kδ inhibitor, to patients with stable COPD or patients with acute exacerbation (AE) of COPD. Methods: In two randomized, double-blind, placebo-controlled clinical trials patients with A) stable COPD (N=28, randomized 3:1) or B) AECOPD (N=44, randomized 1:1) received treatment with inhaled nemiralisib (1mg). Endpoints included induced sputum at various time points before and during treatment for the measurement of transcriptomics (primary endpoint), inflammatory mediators, functional respiratory imaging (FRI), and spirometry. Results: In stable COPD patients, the use of nemiralisib was associated with alterations in sputum neutrophil transcriptomics suggestive of an improvement in migration phenotype; however, the same nemiralisib-evoked effects were not observed in AECOPD. Inhibition of sputum inflammatory mediators was also observed in stable but not AECOPD patients. In contrast, a placebo-corrected improvement in forced expiratory volume in 1 sec of 136 mL (95% Credible Intervals -46, 315mL) with a probability that the true treatment ratio was >0% (Pr(θ>0)) of 93% was observed in AECOPD. However, FRI endpoints remained unchanged. Conclusion: We provide evidence for nemiralisib-evoked changes in neutrophil migration phenotype in stable COPD but not AECOPD, despite improving lung function in the latter group. We conclude that induced sputum can be used for measuring evidence of alteration of neutrophil phenotype in stable patients, and our study provides a data set of the sputum transcriptomic changes during recovery from AECOPD.

Nemiralisib in Patients with an Acute Exacerbation of COPD: Placebo-Controlled, Dose-Ranging Study.

Background: Management of acute exacerbations of chronic obstructive pulmonary disease (COPD) is sometimes inadequate leading to either prolonged duration and/or an increased risk of recurrent exacerbations in the period following the initial event. Objective: To evaluate the safety and efficacy of inhaled nemiralisib, a phosphoinositide 3-kinase δ inhibitor, in patients experiencing an acute exacerbation of COPD. Patients and Methods: In this double-blind, placebo-controlled study, COPD patients (40-80 years, ≥10 pack-year smoking history, current moderate/severe acute exacerbation of COPD requiring standard-of-care treatment) were randomized to placebo or nemiralisib 12.5 µg, 50 µg, 100 µg, 250 µg, 500 µg, or 750 µg (ratio of 3:1:1:1:1:1:3; N=938) for 12 weeks with an exploratory 12-week follow-up period. The primary endpoint was change from baseline in post-bronchodilator FEV1 at week 12. Key secondary endpoints were rate of re-exacerbations, patient-reported outcomes (Exacerbations of Chronic Pulmonary Disease Tool, COPD Assessment Test, St George's Respiratory Questionnaire-COPD), plasma pharmacokinetics (PK) and safety/tolerability. Results: There was no difference in change from baseline FEV1 at week 12 between the nemiralisib and placebo treatment groups (posterior adjusted median difference, nemiralisib 750 µg and placebo: -0.004L (95% CrI: -0.051L to 0.042L)). Overall, there were also no differences between nemiralisib and placebo in secondary endpoints, including re-exacerbations. Plasma PK increased in a dose proportional manner. The most common adverse event for nemiralisib was post-inhalation cough which appeared to be dose-related. Conclusion: The addition of nemiralisib to standard-of-care treatment for 12 weeks did not improve lung function or re-exacerbations in patients with, and following an acute exacerbation of COPD. However, this study demonstrated that large clinical trials recruiting acutely exacerbating patients can successfully be conducted.

Repeatability and sensitivity to change of non-invasive end points in PAH: the RESPIRE study.

End points that are repeatable and sensitive to change are important in pulmonary arterial hypertension (PAH) for clinical practice and trials of new therapies. In 42 patients with PAH, test-retest repeatability was assessed using the intraclass correlation coefficient and treatment effect size using Cohen's d statistic. Intraclass correlation coefficients demonstrated excellent repeatability for MRI, 6 min walk test and log to base 10 N-terminal pro-brain natriuretic peptide (log10NT-proBNP). The treatment effect size for MRI-derived right ventricular ejection fraction was large (Cohen's d 0.81), whereas the effect size for the 6 min walk test (Cohen's d 0.22) and log10NT-proBNP (Cohen's d 0.20) were fair. This study supports further evaluation of MRI as a non-invasive end point for clinical assessment and PAH therapy trials.Trial registration number NCT03841344.

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.

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.

Safety, Tolerability, and Pharmacokinetics of a New Formulation of Nemiralisib Administered via a Dry Powder Inhaler to Healthy Individuals.

PURPOSE: Nemiralisib, a phosphoinositide 3-kinase δ inhibitor, is being investigated as an immunomodulatory agent with anti-inflammatory properties in chronic obstructive pulmonary disease. This study evaluated the pharmacokinetic (PK) properties and safety of a new formulation of nemiralisib that contains 0.4% magnesium stearate. METHODS: In this randomized, double-blind, parallel-group study, healthy individuals received a single dose of 500 or 750 µg of nemiralisib administered via the Ellipta dry powder inhaler (DPI) (n = 6 in each treatment group). Aerodynamic particle size distribution (APSD) data comparing previous and new formulations were available before the study. Serial PK analyses for plasma exposure and safety assessments were performed during the first 24 h after dosing, with follow-up measurements on days 3 and 6 in clinic. FINDINGS: APSD had increases of approximately 6-fold and 2-fold in very fine particle mass and fine particle mass over the previous (Diskus) formulation. In humans, systemic exposure (AUC) was greater after inhalation of 750 versus 500 µg of nemiralisib (AUC0-t: 17,200 h∙pg/mL; 95% CI, 10,900-27,200 h∙pg/mL and 13,100; 95% CI, 8130-21,000 h∙pg/mL, respectively). A low frequency of individual adverse events and no serious adverse events were reported after both doses. IMPLICATIONS: After single-dose inhalation of 500 and 750 µg of nemiralisib from the Ellipta DPI in healthy individuals, plasma PK data were well defined, and as predicted based on previous PK and APSD data, exposure was increased with the new formulation. Nemiralisib was well tolerated with no new safety issues identified. These data supported progression of nemiralisib to a Phase IIb study in patients with chronic obstructive pulmonary disease. ClinicalTrials.gov identifier: NCT03189589.

Translation of Inhaled Drug Optimization Strategies into Clinical Pharmacokinetics and Pharmacodynamics Using GSK2292767A, a Novel Inhaled Phosphoinositide 3-Kinase δ Inhibitor.

This study describes the pharmacokinetic (PK) and pharmaco-dynamic (PD) profile of N-(5-(4-(5-(((2R,6S)-2,6-dimethylmorpholino)methyl)oxazol-2-yl)-1H-indazol-6-yl)-2-methoxypyridin-3-yl)methanesulfonamide (GSK2292767A), a novel low-solubility inhaled phosphoinositide 3-kinase delta (PI3Kδ) inhibitor developed as an alternative to 2-(6-(1H-indol-4-yl)-1H-indazol-4-yl)-5-((4-isopropylpiperazin-1-yl)methyl)oxazole (nemiralisib), which is a highly soluble inhaled inhibitor of PI3Kδ with a lung profile consistent with once-daily dosing. GSK2292767A has a similar in vitro cellular profile to nemiralisib and reduces eosinophilia in a murine PD model by 63% (n = 5, P < 0.05). To explore whether a low-soluble compound results in effective PI3Kδ inhibition in humans, a first time in human study was conducted with GSK2292767A in healthy volunteers who smoke. GSK2292767A was generally well tolerated, with headache being the most common reported adverse event. PD changes in induced sputum were measured in combination with drug concentrations in plasma from single (0.05-2 mg, n = 37), and 14-day repeat (2 mg, n = 12) doses of GSK2292767A. Trough bronchoalveolar lavage (BAL) for PK was taken after 14 days of repeat dosing. GSK2292767A displayed a linear increase in plasma exposure with dose, with marginal accumulation after 14 days. Induced sputum showed a 27% (90% confidence interval 15%, 37%) reduction in phosphatidylinositol-trisphosphate (the product of phosphoinositide 3-kinase activation) 3 hours after a single dose. Reduction was not maintained 24 hours after single or repeat dosing. BAL analysis confirmed the presence of GSK2292767A in lung at 24 hours, consistent with the preclinical lung retention profile. Despite good lung retention, target engagement was only present at 3 hours. This exposure-response disconnect is an important observation for future inhaled drug design strategies considering low solubility to drive lung retention.

Use of autologous 99mTechnetium-labelled neutrophils to quantify lung neutrophil clearance in COPD.

RATIONALE: There is a need to develop imaging protocols which assess neutrophilic inflammation in the lung. AIM: To quantify whole lung neutrophil accumulation in (1) healthy volunteers (HV) following inhaled lipopolysaccharide (LPS) or saline and (2) patients with COPD using radiolabelled autologous neutrophils and single-photon emission computed tomography/CT (SPECT/CT). METHODS: 20 patients with COPD (Global initiative for chronic obstructive lung disease (GOLD) stages 2-3) and 18 HVs were studied. HVs received inhaled saline (n=6) or LPS (50 µg, n=12) prior to the injection of radiolabelled cells. Neutrophils were isolated using dextran sedimentation and Percoll plasma gradients and labelled with 99mTechnetium (Tc)-hexamethylpropyleneamine oxime. SPECT was performed over the thorax/upper abdomen at 45 min, 2 hours, 4 hours and 6 hours. Circulating biomarkers were measured prechallenge and post challenge. Blood neutrophil clearance in the lung was determined using Patlak-Rutland graphical analysis. RESULTS: There was increased accumulation of 99mTc-neutrophils in the lungs of patients with COPD and LPS-challenged subjects compared with saline-challenged subjects (saline: 0.0006±0.0003 mL/min/mL lung blood distribution volume [mean ±1 SD]; COPD: 0.0022±0.0010 mL/min/mL [p<0.001]; LPS: 0.0025±0.0008 mL/min/mL [p<0.001]). The accumulation of labelled neutrophils in 10 patients with COPD who underwent repeat radiolabelling/imaging 7-10 days later was highly reproducible (0.0022±0.0010 mL/min/mL vs 0.0023±0.0009 mL/min/mL). Baseline interleukin (IL)-6 levels in patients with COPD were elevated compared with HVs (1.5±1.06 pg/mL [mean ±1 SD] vs 0.4±0.24 pg/mL). LPS challenge increased the circulating IL-6 levels (7.5±2.72 pg/mL) 9 hours post challenge. CONCLUSIONS: This study shows the ability to quantify 'whole lung' neutrophil accumulation in HVs following LPS inhalation and in subjects with COPD using autologous radiolabelled neutrophils and SPECT/CT imaging. Moreover, the reproducibility observed supports the feasibility of using this approach to determine the efficacy of therapeutic agents aimed at altering neutrophil migration to the lungs.

Evaluation of the Safety, Tolerability, and Pharmacokinetics of GSK2269557 (Nemiralisib) Administered Via Dry Powder Inhaler to Healthy Japanese Subjects.

The aim of the study was to assess the safety, tolerability, and pharmacokinetics of single and repeat doses of nemiralisib administered via a dry powder inhaler to healthy Japanese subjects. This was a single-center, double-blind, randomized, placebo-controlled, parallel, single- and repeat-ascending-dose study. Thirty-six healthy Japanese male subjects were randomized to receive either 1 dose strength of nemiralisib or placebo. The study consisted of a screening period, a single-dose session (session 1), a repeat-dose session (session 2), a 10-day washout period between the sessions, and then a follow-up visit 10 ± 1 days after the last dose of session 2. No serious adverse events were reported. No clinically significant abnormalities were found in clinical laboratory results, vital signs, or spirometry results. Generally, exposure (maximum observed plasma concentration [Cmax ] and area under the concentration-time curve [AUC]) increased with dose in an approximately proportional manner. Plasma Tmax was achieved rapidly at approximately 0.08 hours, and the terminal elimination half-life (T1/2 ) was approximately 40 hours. Tmax and T1/2 did not change between days or doses in the single- and repeat-dose sessions. Following 10 daily doses of 200, 500, and 700 µg nemiralisib, accumulation was observed, and the ratios (session 2, day 10:session 1) for Ro(AUC0-24 ) and R(Cmax ) were 2.4-3.0 and 1.5-1.7, respectively. Steady state was achieved by 6-7 days, based on trough observed plasma drug concentration (Ctrough ) values.

A Multicentre, Randomized, Double-Blind, Placebo-Controlled, Crossover Study To Investigate the Efficacy, Safety, Tolerability, and Pharmacokinetics of Repeat Doses of Inhaled Nemiralisib in Adults with Persistent, Uncontrolled Asthma.

Phosphoinositide 3-kinase δ (PI3Kδ) is a lipid kinase involved in leukocyte recruitment and activation. Activation of PI3Kδ has been linked to airway inflammation and asthma pathogenesis. This randomized, double-blind, placebo-controlled, crossover study investigated the efficacy, safety, tolerability, and pharmacokinetics of a PI3Kδ inhibitor, nemiralisib (GSK2269557), in patients with persistent, uncontrolled asthma. Patients (n = 50) received once-daily inhaled nemiralisib (1000 µg) or placebo for 28 days, with a crossover to the alternative treatment following a 4-week washout period. Spirometry demonstrated no discernible difference in trough forced expiratory volume in 1 second (FEV1) from baseline (adjusted posterior median 7 ml; 95% credible interval -83, 102 ml) between nemiralisib and placebo treatment at day 28 (primary endpoint). These results were supported by most secondary endpoints, including weighted mean FEV1 (0-4 hours) and change in trough forced vital capacity at day 28. Nemiralisib was generally well-tolerated, with few side effects except for post-inhalation cough (nemiralisib: 35%; placebo: 9%). At day 14, sputum interleukin (IL)-5, IL-13, IL-6, and IL-8 levels were reduced by a median of 17%, 7%, 15%, and 8%, respectively, when comparing nemiralisib with placebo [n = 15 (IL-5, IL-8) or 16 (IL-6, IL-13); posterior probability of a true ratio >0%: 78%, 64%, 76%, and 63%, respectively]. These results suggest that nemiralisib inhibited PI3Kδ locally; however, this did not translate into meaningful clinical improvement. Further studies will investigate the potential efficacy of nemiralisib in patients with asthma with other specific more severe phenotypes, including those who are colonized with bacteria and frequently exacerbate.