Pharmacokinetics of zanamivir following intravenous administration to subjects with and without renal impairment.

Intravenous zanamivir is in clinical development for the treatment of influenza in hospitalized patients, many of whom have renal impairment. This open-label study evaluated zanamivir pharmacokinetics and clinical safety following a single 100-mg intravenous infusion dose in subjects with impaired renal function compared with normal renal function. Male and female subjects between 18 and 79 years of age were recruited, four subjects to each renal function group (normal function and mild, moderate, and severe impairment). Serial blood samples were collected up to 24 h after dose administration (48 h for the severe renal impairment group) to estimate zanamivir serum pharmacokinetic parameters. Urine was collected over the same 24-h (or 48-h) period for estimation of renal clearance (CLR). Zanamivir pharmacokinetics were assessed by regression analysis of systemic clearance (CL) and CLR as a function of creatinine clearance (CLCR). Safety evaluations included adverse-event monitoring, vital signs, electrocardiogram, and clinical laboratory assessments. Zanamivir clearance (total and renal) significantly decreased with decreasing renal function, with corresponding increases in area under the concentration-time curve and elimination half-life. Renal impairment had no apparent effects on peak concentration or volume of distribution. Regression analysis indicated that zanamivir clearance was highly correlated (r(2) = 0.89) with creatinine clearance: CL ≅ 7.08 + 0.826 · CLCR. There were no patterns or trends in adverse events, and no new safety concerns were identified following administration of intravenous zanamivir. Results from this study support the inclusion of subjects with renal impairment, with appropriate dose adjustment, in studies to evaluate intravenous zanamivir in the treatment of influenza.

Efficacy and safety of topically applied therapeutic ammonia oxidising bacteria in adults with mild-to-moderate atopic dermatitis and moderate-to-severe pruritus: a randomised, double-blind, placebo-controlled, dose-ranging, phase 2b trial.

Background: Topical anti-inflammatory therapy is a cornerstone of treatment for atopic dermatitis (AD). However, many unmet needs remain with existing therapies. B244 is a live topical biotherapeutic being tested for the reduction of pruritus and improvement of eczema signs in patients with AD. We aimed to assess the safety and efficacy of B244, compared to vehicle, for patients with mild-to-moderate AD and moderate-to-severe pruritus. Methods: In this randomised, placebo-controlled, double-blind phase 2b trial, adults aged 18-65 years with mild-to-moderate AD and moderate-to-severe pruritus were enrolled across 56 sites in the USA. Patients were randomised 1:1:1 into a low-dose (optical density at 600 nm [OD] 5.0), high-dose (OD 20.0), or vehicle group for the 4-week treatment period and a 4 week follow-up period. Patients were instructed to apply the topical spray twice daily throughout the treatment period. Randomisation was centrally based (random alternating blocks of 6 and 3) and stratified by site. All participants, investigators, and those assessing outcomes were blinded to the treatment group assignments. The primary endpoint was the mean change in pruritus as measured by the Worst Itch Numeric Rating Scale (WI-NRS) at 4 weeks. Safety was tracked throughout the study. Primary efficacy analyses included the modified intent-to-treat (mITT) population, encompassing those who received at least one dose of study drug and attended at least one post-baseline visit. The safety population included all participants who received at least one does of study drug. This study is registered with ClinicalTrials.gov, NCT04490109. Findings: Between June 4, 2020 and October 22, 2021, 547 eligible patients were enrolled. All study endpoints were meaningfully improved with B244 compared to vehicle. The WI-NRS score was reduced by 34% (-2.8 B244 vs -2.1 placebo, p = 0.014 and p = 0.015 for OD 20.0 and OD 5.0), from a baseline score of >8. B244 was well tolerated with no serious adverse events (SAEs); treatment-emergent adverse events (TEAEs) and treatment related TEAEs were low in incidence, mild in severity, and transient. 33 (18%) of 180 patients given B244 OD 5.0, 29 (16%) of 180 patients given B244 OD 20.0, and 17 (9%) of 186 patients given placebo reported treatment-emergent adverse events; headache was the most frequent (3%, 2%, and 1%, respectively). Interpretation: B244 was well tolerated and demonstrated improved efficacy compared to vehicle in all primary, secondary, and exploratory endpoints and should be further developed as a novel, natural, fast-acting topical spray treatment option for AD and associated pruritus. Funding: AOBiome Therapeutics.

Zanamivir pharmacokinetics and pulmonary penetration into epithelial lining fluid following intravenous or oral inhaled administration to healthy adult subjects.

Zanamivir serum and pulmonary pharmacokinetics were characterized following intravenous (i.v.) or oral inhaled administration. I.v. zanamivir was given as intermittent doses of 100 mg, 200 mg, and 600 mg every 12 h (q12h) for two doses or as a continuous infusion (6-mg loading dose followed by 3 mg/h for 12 h). Oral inhaled zanamivir (two 5-mg inhalations q12h for two doses) was evaluated as well. Each zanamivir regimen was administered to six healthy subjects with serial pharmacokinetic sampling. In addition, a single bronchoalveolar lavage (BAL) fluid sample was collected at various time points and used to calculate epithelial lining fluid (ELF) drug concentrations for each subject. For intermittent i.v. administration of 100 mg, 200 mg, and 600 mg zanamivir, the median zanamivir concentrations in ELF collected 12 h after dosing were 74, 146, and 419 ng/ml, respectively, each higher than the historic mean 50% inhibitory concentrations for the neuraminidases of wild-type strains of influenza A and B viruses. Median ELF/serum zanamivir concentration ratios ranged from 55 to 79% for intermittent i.v. administration (when sampled 12 h after the last dose) and 43 to 45% for continuous infusion (when sampled 6 to 12 h after the start of the infusion). For oral inhaled zanamivir, the median zanamivir concentrations in ELF were 891 ng/ml for the first BAL fluid collection and 326 ng/ml for subsequent BAL fluid collections (when sampled 12 h after the last dose); corresponding serum drug concentrations were undetectable. This study demonstrates zanamivir's penetration into the human pulmonary compartment and supports the doses selected for the continuing development of i.v. zanamivir in clinical studies of influenza.

Safety, tolerability and pharmacokinetics of orally inhaled zanamivir: a randomized study comparing Rotacap/Rotahaler and Rotadisk/Diskhaler in healthy adults.

BACKGROUND: During a pandemic, the need for available anti-influenza medications increases. There has been extensive use of the approved zanamivir Rotadisk/Diskhaler but no clinical data are available for administration by an alternative Rotacap/Rotahaler presentation. METHODS: In this randomized three-way crossover study, each healthy adult received zanamivir 10 mg every 12 h for 5 days via Rotadisk/Diskhaler, via Rotacap/Rotahaler and placebo via Rotacap/Rotahaler, with a washout period between treatments. Safety assessments were conducted throughout the study and at follow-up. Serial blood samples for pharmacokinetic analysis were collected over a 12-h dose interval on day 5 of each treatment period. Pharmacokinetic parameters were compared using a mixed-effects model. RESULTS: A total of 18 healthy adults were recruited and 17 subjects completed the study. A total of 20 adverse events (AEs) were reported (all grade 1) by nine subjects, with no AE reported ≥1× in any treatment group. Nasal congestion, reported by one subject in the zanamivir Rotadisk/Diskhaler group, was the only drug-related AE. No serious AEs or withdrawals due to AEs occurred during the study. There were no significant changes in clinical laboratory values, vital signs or spirometry. Serum zanamivir exposures were similar after administration via Rotacap/Rotahaler and Rotadisk/Diskhaler. Both oral inhalation presentations are likely to deliver similar zanamivir concentrations to sites of influenza infection in the respiratory tract. CONCLUSIONS: The safety and pharmacokinetic results from this study support the use of the Rotacap/Rotahaler presentation, potentially allowing an increased number of zanamivir treatment courses to be supplied in the event of an influenza pandemic.

Safety and pharmacokinetics of brecanavir, a novel human immunodeficiency virus type 1 protease inhibitor, following repeat administration with and without ritonavir in healthy adult subjects.

Brecanavir (BCV) is a novel, potent protease inhibitor in development for the treatment of human immunodeficiency virus (HIV-1) infection with low nM in vitro 50% inhibitory concentrations (IC50s) against many multiprotease inhibitor resistant viruses. This study was a double-blind, randomized, placebo-controlled repeat-dose escalation to evaluate the safety, tolerability, and pharmacokinetics of BCV, with or without ritonavir (RTV), in 68 healthy subjects. Seven sequential cohorts (n=10) received BCV (50 to 600 mg) in combination with 100 mg RTV (every 12 h [q12h] or q24h) or alone at 800 mg q12h for 15 days. BCV alone or in combination with RTV was well tolerated, with no serious adverse events reported. The most common drug-related adverse event was headache. BCV was readily absorbed with median time to maximum concentration of drug in serum values ranging from 2.5 to 5.0 h postdose following single- and repeat-dose administration of BCV alone and BCV with RTV 100 mg. Geometric mean BCV accumulation ratios ranged from 1.4 to 1.56 following BCV-RTV q24h regimens and from 1.84 to 4.93 following BCV q12h regimens. BCV steady state was generally achieved by day 13 in all groups. All day 15 BCV-RTV trough concentration values in q12h regimens reached or surpassed the estimated protein-binding corrected in vitro IC50 target BCV concentration of 28 ng/ml for highly resistant isolates. The pharmacokinetic and safety profile of BCV-RTV supports continued investigation in HIV-1-infected subjects.

Host absence of CCR5 potentiates dendritic cell vaccination.

Previous work has shown that dendritic cells (DCs) express specific chemokine receptors that allow for coordinated movement in vivo. To test the in vivo relevance of this, we used a murine melanoma system and knockout mice to investigate the function of the chemokine receptor CCR5 and its ligands, CCR ligand (CCL)3 and CCL5. We found that the lack of CCR5 in the host mouse resulted in delayed tumor growth, but this effect was overcome at a higher tumor load. With the administration of tumor charged DCs, CCR5(-/-) mice that had previously been injected with tumor were completely protected from tumor. This effect was dependent on the dose of tumor cells and the expression of CCR5 on the DC and its absence in the host. In contrast, the loss of the CCR5 ligand, CCL3, led to an early delay in tumor growth that did not persist, while the absence of the CCR5 ligand, CCL5, had no effect. Blocking the activity of CCR5 in the host may represent a new strategy for enhancing the activity of a therapeutic melanoma DC vaccine.