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A drug–drug interaction (DDI) study was conducted to evaluate the effect of icenticaftor (QBW251) on the pharmacokinetics (PK) of a 5‐probe cytochrome P450 (CYP) substrate cocktail, guided by in vitro studies in human hepatocytes and liver microsomes. Another DDI study investigated the effect of icenticaftor on the PK and pharmacodynamics (PD) of a monophasic oral contraceptive (OC) containing ethinyl estradiol (EE) and levonorgestrel (LVG) in premenopausal healthy female subjects. The static‐mechanistic DDI assessment indicated that icenticaftor may moderately induce the metabolic clearance of co‐medications metabolized by CYP3A4 (area under the concentration–time curve [AUC] ratio: 0.47) and potentially CYP2C; icenticaftor may also weakly inhibit the metabolic clearance of co‐medications metabolized by CYP1A2 and CYP3A4 (AUC ratio: 1.35 and 1.86, respectively) and moderately inhibit CYP2B6 (AUC ratio: 2.11). In the CYP substrate cocktail DDI study, icenticaftor 300 mg twice daily (b.i.d.) moderately inhibited CYP1A2 (AUC ratio: 3.35) and CYP2C19 (AUC ratio: 2.70). As expected from the results of the in vitro studies, weak induction was observed for CYP3A4 (AUC ratio: 0.51) and CYP2C8 (AUC ratio: 0.66). In the OC DDI study, co‐administration of icenticaftor 450 mg b.i.d. with monophasic OC containing 30‐μg EE and 150‐μg LVG once daily reduced the plasma exposure of both components by approximately 50% and led to increased levels of follicle‐stimulating hormone and luteinizing hormone. These results provide valuable guidance for the use of icenticaftor in patients taking concomitant medications that are substrates of CYP enzymes or patients using OCs. [ABSTRACT FROM AUTHOR]

There is an urgent need for new drugs to treat malaria, with broad therapeutic potential and novel modes of action, to widen the scope of treatment and to overcome emerging drug resistance. Here we describe the discovery of DDD107498, a compound with a potent and novel spectrum of antimalarial activity against multiple life-cycle stages of the Plasmodium parasite, with good pharmacokinetic properties and an acceptable safety profile. DDD107498 demonstrates potential to address a variety of clinical needs, including single-dose treatment, transmission blocking and chemoprotection. DDD107498 was developed from a screening programme against blood-stage malaria parasites; its molecular target has been identified as translation elongation factor 2 (eEF2), which is responsible for the GTP-dependent translocation of the ribosome along messenger RNA, and is essential for protein synthesis. This discovery of eEF2 as a viable antimalarial drug target opens up new possibilities for drug discovery.

Icenticaftor (QBW251) is a potentiator of the cystic fibrosis transmembrane receptor. Based on its mechanism of action, icenticaftor is expected to provide benefits in patients with chronic obstructive pulmonary disease by restoring mucociliary clearance, which would eventually lead to a reduction of bacterial colonization and related inflammatory cascade. A placebo‐ and positive‐controlled, 4‐way crossover thorough QT study was conducted in 46 healthy participants with the objective to assess the effect of therapeutic (300 mg twice daily for 6 days) and supratherapeutic (750 mg twice daily for 6 days) oral doses of icenticaftor on electrocardiogram parameters, including concentration‐corrected QT (QTc) analysis. Moxifloxacin (400 mg, oral) was used as a positive control. In the concentration‐QTc analysis performed on pooled data from Day 1 and Day 6 (steady state), the estimated population slope was shallow and slightly negative: –0.0012 ms/ng/mL. The effect on the Fridericia corrected QT (QTcF) interval (∆ΔQTcF) was predicted to be −1.3 milliseconds at the icenticaftor 300‐mg twice‐daily peak concentration (geometric mean was 1094 ng/mL) and −5.5 milliseconds at the 750‐mg twice‐daily peak concentration (geometric mean Cmax was 4529 ng/mL) indicated a mild shortening effect of icenticaftor on QTcF interval length. The results of the by‐time‐point analysis indicated least squares placebo corrected mean ∆∆QTcF across time points ranged from –7.9 to 0.1 milliseconds at 1 and 24 hours after dosing both on Day 6 in the 750‐mg dose group compared with –3.7 to 1.6 milliseconds at 1.5 and 24 hours after dosing on Day 1 in the 300‐mg dose group. Assay sensitivity was demonstrated with moxifloxacin. The large accumulation of exposures, especially the 4.3‐fold increase in peak plasma concentration observed at the icenticaftor 750‐mg twice‐daily dosage compared with Icenticaftor 300 mg twice daily (2.3‐fold) on Day 6 provided a large concentration range (up to 9540 ng/mL) to evaluate the effect of icenticaftor on ΔΔQTcF. Based on the concentration–QTc analysis, an effect on ΔΔQTcF exceeding 10 milliseconds can be excluded within the full observed ranges of plasma concentrations on icenticaftor, up to approximately 9540 ng/mL. Icenticaftor at the studied doses demonstrated a mild shortening in QTcF, which is unlikely to be of clinical relevance in a therapeutic setting. [ABSTRACT FROM AUTHOR]

Author(s): Beatriz Baragaa; Irene Hallyburton; Marcus C. S. Lee; Neil R. Norcross; Raffaella Grimaldi; Thomas D. Otto; William R. Proto; Andrew M. Blagborough; Stephan Meister; Grennady Wirjanata; Andrea Ruecker; Leanna [...]

Icenticaftor (QBW251) is a potentiator of the cystic fibrosis transmembrane conductance regulator protein and is currently in clinical development for the treatment of chronic obstructive pulmonary disease and chronic bronchitis. An absorption, distribution, metabolism, and excretion study was performed at steady state to determine the pharmacokinetics, mass balance, and metabolite profiles of icenticaftor in humans. In this open-label study, six healthy men were treated with unlabeled oral icenticaftor (400 mg b.i.d.) for 4 days. A single oral dose of [ 14 C]icenticaftor was administered on Day 5, and unlabeled icenticaftor was administered twice daily from the evening of Day 5 to Day 12. Unchanged icenticaftor accounted for 18.5% of plasma radioactivity. Moderate to rapid absorption of icenticaftor was observed (median time to reach peak or maximum concentration: 4 hours), with 93.4% of the dose absorbed. It exhibited moderate distribution (Vz/F: 335 L) and was extensively metabolized, principally through N-glucuronidation, O-glucuronidation, and/or O-demethylation. The metabolites M8 and M9, formed by N-glucuronidation and O-glucuronidation of icenticaftor, respectively, represented the main entities detected in plasma (35.3% and 14.5%, respectively) in addition to unchanged icenticaftor (18.5%). The apparent mean terminal half-life of icenticaftor was 15.4 hours in blood and 20.6 hours in plasma. Icenticaftor was eliminated from the body mainly through metabolism followed by renal excretion, and excretion of radioactivity was complete after 9 days. In vitro phenotyping of icenticaftor showed that cytochrome P450 and uridine diphosphate glucuronosyltransferase were responsible for 31% and 69% of the total icenticaftor metabolism in human liver microsomes, respectively. This study provided invaluable insights into the disposition of icenticaftor. SIGNIFICANCE STATEMENT: The absorption, distribution, metabolism, and excretion of a single radioactive oral dose of icenticaftor was evaluated at steady state to investigate the nonlinear pharmacokinetics observed previously with icenticaftor. [ 14 C]Icenticaftor demonstrated good systemic availability after oral administration and was extensively metabolized and moderately distributed to peripheral tissues. The most abundant metabolites, M8 and M9, were formed by N-glucuronidation and O-glucuronidation of icenticaftor, respectively. Phenotyping demonstrated that [ 14 C]icenticaftor was metabolized predominantly by UGT1A9 with a remarkably low K m value., (Copyright © 2024 by The Author(s).)

A drug-drug interaction (DDI) study was conducted to evaluate the effect of icenticaftor (QBW251) on the pharmacokinetics (PK) of a 5-probe cytochrome P450 (CYP) substrate cocktail, guided by in vitro studies in human hepatocytes and liver microsomes. Another DDI study investigated the effect of icenticaftor on the PK and pharmacodynamics (PD) of a monophasic oral contraceptive (OC) containing ethinyl estradiol (EE) and levonorgestrel (LVG) in premenopausal healthy female subjects. The static-mechanistic DDI assessment indicated that icenticaftor may moderately induce the metabolic clearance of co-medications metabolized by CYP3A4 (area under the concentration-time curve [AUC] ratio: 0.47) and potentially CYP2C; icenticaftor may also weakly inhibit the metabolic clearance of co-medications metabolized by CYP1A2 and CYP3A4 (AUC ratio: 1.35 and 1.86, respectively) and moderately inhibit CYP2B6 (AUC ratio: 2.11). In the CYP substrate cocktail DDI study, icenticaftor 300 mg twice daily (b.i.d.) moderately inhibited CYP1A2 (AUC ratio: 3.35) and CYP2C19 (AUC ratio: 2.70). As expected from the results of the in vitro studies, weak induction was observed for CYP3A4 (AUC ratio: 0.51) and CYP2C8 (AUC ratio: 0.66). In the OC DDI study, co-administration of icenticaftor 450 mg b.i.d. with monophasic OC containing 30-μg EE and 150-μg LVG once daily reduced the plasma exposure of both components by approximately 50% and led to increased levels of follicle-stimulating hormone and luteinizing hormone. These results provide valuable guidance for the use of icenticaftor in patients taking concomitant medications that are substrates of CYP enzymes or patients using OCs., (© 2024 The Author(s). Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)