Pharmacokinetics of long-acting lenacapavir in participants with hepatic or renal impairment.

Lenacapavir is a novel, first-in-class, multistage inhibitor of HIV-1 capsid function approved for the treatment of multidrug-resistant HIV-1 infection in combination with other antiretrovirals for heavily treatment-experienced people with HIV. Two Phase 1, open-label, parallel-group, single-dose studies assessed the pharmacokinetics (PK) of lenacapavir in participants with moderate hepatic impairment [Child-Pugh-Turcotte (CPT) Class B: score 7-9] or severe renal impairment [15 ≤ creatinine clearance (CLcr) ≤29 mL/min] to inform lenacapavir dosing in HIV-1-infected individuals with organ impairment. In both studies, a single oral dose of 300 mg lenacapavir was administered to participants with normal (n = 10) or impaired (n = 10) hepatic/renal function who were matched for age (±10 years), sex, and body mass index (±20%). Lenacapavir exposures [area under the plasma concentration-time curve from time 0 to infinity (AUCinf) and maximum concentration (Cmax)] were approximately 1.47- and 2.61-fold higher, respectively, in participants with moderate hepatic impairment compared to those with normal hepatic function, whereas lenacapavir AUCinf and Cmax were approximately 1.84- and 2.62-fold higher, respectively, in participants with severe renal impairment compared to those with normal renal function. Increased lenacapavir exposures with moderate hepatic or severe renal impairment were not considered clinically meaningful. Lenacapavir was considered generally safe and well tolerated in both studies. These results support the use of approved lenacapavir dosing regimen in patients with mild (CPT Class A: score 5-6) or moderate hepatic impairment as well as in patients with mild (60 ≤ CLcr ≤ 89 mL/min), moderate (30 ≤ CLcr ≤ 59 mL/min), and severe renal impairment.

Remdesivir for COVID-19 in Hospitalized Children: A Phase 2/3 Study.

OBJECTIVES: Remdesivir decreases the risk of SARS-CoV-2 infection progressing to severe disease in adults. This study evaluated remdesivir safety and pharmacokinetics in infants and children. METHODS: This was a phase 2/3, open-label trial in children aged 28 days to 17 years hospitalized for polymerase chain reaction-confirmed SARS-CoV-2 infection. Participants received for ≤10 days once-daily intravenous remdesivir doses defined using physiologically based pharmacokinetic modeling (for ≥40 kg, 200 mg day 1, then 100 mg/day; for age ≥28 days and ≥3 to <40 kg, 5 mg/kg day 1, then 2.5 mg/kg/day). Sparse pharmacokinetic samples were analyzed using population-pharmacokinetic approaches for remdesivir and metabolites GS-704277 and GS-441524. RESULTS: Among 53 participants, at enrollment the median (Q1, Q3) number of days of COVID-19 symptoms was 5 (3, 7) and hospitalization was 1 (1, 3). Underlying conditions included obesity in 19 (37%), asthma in 11 (21%), and cardiac disorders in 11 (21%). Median duration of remdesivir treatment was 5 days (range, 1-10). Remdesivir treatment had no new apparent safety trends. Two participants discontinued treatment because of adverse events including elevated transaminases; both had elevated transaminases at baseline. Three deaths occurred during treatment (and 1 after). When compared with phase 3 adult data, estimated mean pediatric parameters (area under the concentration-time curve over 1 dosing interval, AUCτ, Cmax, and Cτ) were largely overlapping but modestly increased (remdesivir, 33%-129%; GS-704277, 37%-124%; GS-441524, 0%-60%). Recovery occurred for 62% of participants on day 10 and 83% at last assessment. CONCLUSIONS: In infants and children with COVID-19, the doses of remdesivir evaluated provided drug exposure similar to adult dosing. In this study with a small sample size, no new safety concerns were observed.

Pharmacokinetics, Disposition, and Biotransformation of [14C]Lenacapavir, a Novel, First-in-Class, Selective Inhibitor of HIV-1 Capsid Function, in Healthy Participants Following a Single Intravenous Infusion.

BACKGROUND AND OBJECTIVE: Lenacapavir (LEN) is a novel, first-in-class, multistage, selective inhibitor of human immunodeficiency virus type 1 (HIV-1) capsid function recently approved for the treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection. The purpose of this multicohort study was to evaluate the pharmacokinetics, metabolism, excretion, safety, and tolerability of LEN following a single intravenous (IV) infusion of 10 mg LEN or 20 mg [14C]LEN in healthy participants. METHODS: Twenty-one healthy adult participants were enrolled into the study and received either a single IV dose of 10 mg LEN (n = 8 active, n = 3 placebo; cohort 1) or a single IV dose of 20 mg [14C]LEN containing 200 µCi (n = 10; cohort 2). Blood, urine, and feces samples (when applicable) were collected after dosing, and radioactivity (cohort 2) was assessed using liquid scintillation counting in both plasma and excreta. LEN in plasma was quantified by liquid chromatography (LC) tandem mass spectroscopy (MS/MS) method bioanalysis. Metabolite profiling in plasma and excreta were performed using LC-fraction collect (FC)-high-resolution MS and LC-FC-accelerator mass spectrometry in plasma. RESULTS: Between the 10 mg and 20 mg doses of LEN, the observed plasma exposure of LEN doubled, while the elimination half-life was similar. Following administration of 20 mg [14C]LEN (200 µCi), the mean cumulative recovery of [14C] radioactivity was 75.9% and 0.24% from feces and urine, respectively. The mean whole [14C] blood-to-plasma concentration ratio was 0.5-0.7, which showed a low distribution of LEN to red blood cells. Intact LEN was the predominant circulating species in plasma (representing 68.8% of circulating radioactivity), and no single metabolite contributed to > 10% of total radioactivity exposure through 1176 h postdose. Similarly, intact LEN was the most abundant component (32.9% of administered dose; 75.9% of recovered dose) measured in feces, with metabolites accounting for trace amounts. These results suggest metabolism of LEN is not a primary pathway of elimination. Of the metabolites observed in the feces, the three most abundant metabolites were direct phase 2 conjugates (glucuronide, hexose, and pentose conjugates), with additional metabolites formed to a lesser extent via other pathways. The administered LEN IV doses were generally safe and well-tolerated across participants in this study. CONCLUSIONS: The results of this mass balance study indicated that LEN was majorly eliminated as intact LEN via the feces. The renal pathway played a minor role in LEN elimination (0.24%). In addition, no major circulating metabolites in plasma or feces were found, indicating minimal metabolism of LEN.

A study of the pharmacokinetics, safety, and efficacy of bictegravir/emtricitabine/tenofovir alafenamide in virologically suppressed pregnant women with HIV.

OBJECTIVE: The objective of this study was to assess the pharmacokinetics, safety, and efficacy and confirm the dose of once-daily bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF; B/F/TAF) during pregnancy. DESIGN: An open-label, multicenter, single-arm, phase 1b study (NCT03960645) was conducted in 33 virologically suppressed pregnant women with HIV-1. METHODS: Participants received B/F/TAF (50/200/25 mg) from the second or third trimester through ∼16 weeks postpartum. Steady-state maternal plasma pharmacokinetic samples were collected at the second and third trimesters and 6 and 12 weeks postpartum for BIC, FTC, and TAF. Neonates ( n  = 29) were followed from birth to 4-8 weeks with sparse washout pharmacokinetic sampling for BIC and TAF. The proportion of participants with HIV-1 RNA less than 50 copies/ml at delivery (missing = excluded) was evaluated. RESULTS: Mean areas under the concentration-time curve over the dosing interval (AUC tau ) for BIC, FTC, and TAF were lower during pregnancy versus postpartum but were closer to AUC tau values for nonpregnant adults with HIV reported in other studies. Geometric least-squares mean ratios for BIC, FTC, and TAF AUC tau during pregnancy versus postpartum ranged from 41 to 45%, 64 to 69% and 57 to 78%, respectively. Mean BIC trough concentrations during pregnancy were more than 6.5-fold greater than the protein-adjusted 95% effective concentration. In neonates, the median BIC half-life was 43 h. Virologic suppression was maintained in all adult participants throughout the study, with no virologic failure or treatment-emergent resistance to HIV-1, no discontinuations because of adverse events, and no perinatal transmission. CONCLUSION: Exposures to BIC, FTC, and TAF were lower during pregnancy than postpartum. However, mean BIC trough concentrations were maintained at levels indicative of efficacious exposure, and FTC/TAF data were concordant with published literature in this population. Pharmacokinetic and safety data, combined with maintenance of robust virologic suppression, suggest that once-daily B/F/TAF without dose adjustment is appropriate during pregnancy.

Pharmacokinetics, safety, and tolerability of inhaled remdesivir in healthy participants.

Intravenous remdesivir (RDV) is US Food and Drug Administration-approved for hospitalized and nonhospitalized individuals with coronavirus disease 2019. RDV undergoes intracellular metabolic activation to form the active triphosphate, GS-443902, and other metabolites. Alternative administration routes, including localized pulmonary delivery, can lower systemic exposure and maximize exposure at the site of action. This study evaluated the pharmacokinetics (PK) and safety of inhaled RDV in healthy adults. This phase Ia, randomized, placebo-controlled study evaluated inhaled RDV in healthy participants randomized 4:1 to receive RDV or placebo as single doses (4 cohorts) or multiple once-daily doses (3 cohorts). Doses in cohorts 1-6 were administered as an aerosolized solution for inhalation through a sealed facemask; doses in cohort 7 were administered as an aerosolized solution for inhalation through a mouthpiece. Safety was assessed throughout the study. Seventy-two participants were enrolled (inhaled RDV, n = 58 and placebo, n = 14). Following single RDV doses, RDV, GS-704277, and GS-441524 plasma PK parameters indicated dose-proportional increases in area under the concentration-time curve (AUC) extrapolated to infinite time, AUC from time zero to last quantifiable concentration, and maximum observed concentration. Analyte plasma concentrations after multiple RDV doses were consistent with those for single-dose RDV. Analyte plasma exposures were lower when RDV was administered with a mouthpiece versus a sealed facemask. The most common adverse events included nausea, dizziness, and cough. Single- and multiple-dose inhaled RDV exhibited linear and dose-proportional plasma PK. Administration of RDV via inhalation was generally safe and well-tolerated.

Current State and Opportunities with Long-acting Injectables: Industry Perspectives from the Innovation and Quality Consortium "Long-Acting Injectables" Working Group.

Long-acting injectable (LAI) formulations can provide several advantages over the more traditional oral formulation as drug product opportunities. LAI formulations can achieve sustained drug release for extended periods of time, which results in less frequent dosing requirements leading to higher patient adherence and more optimal therapeutic outcomes. This review article will provide an industry perspective on the development and associated challenges of long-acting injectable formulations. The LAIs described herein include polymer-based formulations, oil-based formulations, and crystalline drug suspensions. The review discusses manufacturing processes, including quality controls, considerations of the Active Pharmaceutical Ingredient (API), biopharmaceutical properties and clinical requirements pertaining to LAI technology selection, and characterization of LAIs through in vitro, in vivo and in silico approaches. Lastly, the article includes a discussion around the current lack of suitable compendial and biorelevant in vitro models for the evaluation of LAIs and its subsequent impact on LAI product development and approval.

A randomized controlled trial comparing PF-06438179/GP1111 (an infliximab biosimilar) and infliximab reference product for treatment of moderate to severe active rheumatoid arthritis despite methotrexate therapy.

BACKGROUND: This double-blind, active-controlled, randomized, multinational study evaluated the efficacy, safety, pharmacokinetics (PK), and immunogenicity of PF-06438179/GP1111 (IxifiTM/Zessly®), an infliximab biosimilar, vs infliximab (Remicade®) reference product sourced from the European Union (infliximab-EU) in biologic-naïve patients with moderate to severe active rheumatoid arthritis (RA) despite methotrexate therapy. This paper reports results from the initial 30-week treatment period. METHODS: Patients (N = 650) were stratified by geographic region and randomized 1:1 to PF-06438179/GP1111 or infliximab-EU (3 mg/kg intravenous at weeks 0, 2, and 6, then every 8 weeks). Dose escalation to 5 mg/kg was allowed starting at week 14 for patients with inadequate RA response. The primary endpoint was American College of Rheumatology criteria for ≥ 20% clinical improvement (ACR20) response at week 14. Therapeutic equivalence was declared if the two-sided 95% CI for the treatment difference was within the symmetric equivalence margin of ± 13.5%. Statistical analysis was also performed with a two-sided 90% CI using an asymmetric equivalence margin (- 12.0%, 15.0%). RESULTS: Patients (80.3% female; 79.4% seropositive) had a mean RA duration of 6.9 years, and mean baseline Disease Activity Score in 28 joints, four components based on C-reactive protein was 6.0 in both arms. Week 14 ACR20 in the intention-to-treat population was 62.7% for PF-06438179/GP1111 and 64.1% for infliximab-EU. Week 14 ACR20 using nonresponder imputation was 61.1% for PF-06438179/GP1111 and 63.5% for infliximab-EU, and the 95% (- 9.92%, 5.11%) and 90% (- 8.75%, 4.02%) CIs for the treatment difference (- 2.39%) were entirely contained within the prespecified symmetric and asymmetric equivalence margins, respectively. No differences were observed between arms for secondary efficacy endpoints. Overall postdose antidrug antibody (ADA) rates through week 30 were 48.6% and 51.2% for PF-06438179/GP1111 and infliximab-EU, respectively. Efficacy and immunogenicity were similar between treatments for patients with dose escalation (at or after week 14), as well as between treatments for patients without dose escalation. Safety profiles of PF-06438179/GP1111 and infliximab-EU were similar, with no clinically meaningful differences observed between arms, including after ADA development. Serum drug concentrations were similar between arms at each time point during the initial 30-week treatment period. CONCLUSION: PF-06438179/GP1111 and infliximab-EU demonstrated similar efficacy, safety, immunogenicity, and PK with or without dose escalation in patients with moderate to severe active RA on background methotrexate. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02222493 . Registered on 21 August 2014. EudraCT, 2013-004148-49 . Registered on 14 July 2014.

A randomized study comparing the pharmacokinetics of the potential biosimilar PF-06438179/GP1111 with Remicade® (infliximab) in healthy subjects (REFLECTIONS B537-01).

BACKGROUND: To demonstrate pharmacokinetic (PK) similarity of PF-06438179/GP1111, a potential biosimilar to Remicade®, to Remicade® sourced from European Union (infliximab-EU) and United States (infliximab-US), and of infliximab-EU to infliximab-US. METHODS: In this phase I, parallel-group, three-arm trial, healthy adult subjects were randomized to receive a single 10-mg/kg intravenous infusion of PF-06438179/GP1111, infliximab-EU, or infliximab-US. PK, and safety and immunogenicity evaluations were performed over 8 and 12 weeks, respectively. PK similarity was established if the 90% confidence intervals (CIs) of the test-to-reference ratios for PK parameters, Cmax, AUCT, and AUCinf, were within the 80.00-125.00% pre-specified equivalence window. RESULTS: Of 151 subjects randomized, 146 received study treatment; 130 were eligible for PK similarity assessment. Serum concentration-time profiles were similar across the three treatments. The 90% CIs for test-to-reference ratios for Cmax, AUCT, and AUCinf were within 80.00-125.00% for comparison of PF-06438179/GP1111 to infliximab-EU and infliximab-US, and of infliximab-EU to infliximab-US. Similar numbers of subjects across treatment groups experienced adverse events. Anti-drug and neutralizing antibody profiles were largely similar among groups. CONCLUSIONS: This study demonstrated PK similarity of PF-06438179/GP1111 to infliximab-EU and infliximab-US, and of infliximab-EU to infliximab-US. All three products displayed comparable safety and immunogenicity profiles. TRIAL REGISTRATION: CT.gov identifier NCT01844804.

Blockade of [11C](+)-PHNO binding in human subjects by the dopamine D3 receptor antagonist ABT-925.

Dopamine D3 receptors are preferentially localized in the limbic system and midbrain, and thus may be involved in the pathophysiology of neuropsychiatry disorders. [11C](+)-PHNO is the first preferential D3 receptor radioligand in humans, yet there are no blockade studies with a D3 receptor antagonist in humans. This study characterized the blockade of [11C](+)-PHNO binding by ABT-925, a D3 receptor antagonist, in healthy male subjects. Sixteen subjects underwent 2-3 positron emission tomography (PET) scans, at baseline and following one or two doses of ABT-925 ranging from 50 mg to 600 mg. Receptor occupancies were estimated for globus pallidus, substantia nigra, caudate, putamen, and ventral striatum. At the 600-mg dose (n=9), ABT-925 receptor occupancy (mean+/-s.d.) was higher in substantia nigra (75+/-10%) and globus pallidus (64+/-22%) than in ventral striatum (44+/-17%), caudate (40+/-18%) and putamen (38+/-17%) (ANOVA: F4,140=15.02, p<0.001). The fractions of [11C](+)-PHNO binding attributable to D3 receptors in D3 receptor-rich regions were 100% (substantia nigra) and 90% (globus pallidus), and in D2 receptor-rich regions were 55% (caudate) and 53% (putamen). The ED50 of ABT-925 was 4.37 microg/ml across regions. Our results demonstrate that [11C](+)-PHNO binding can be blocked by a D3 receptor antagonist and confirm preclinical findings that [11C](+)-PHNO signal in the substantia nigra and globus pallidus is mainly reflective of its binding to D3 receptors. Thus, [11C](+)-PHNO seems a suitable PET radiotracer to estimate D3 receptor occupancy in humans.