Qualified kidney injury biomarkers demonstrate value during early clinical drug development.

Drug-induced kidney injury (DIKI) is of significant concern, both during drug development and in clinical practice. We report a patient-centric approach for clinical implementation of the FDA-qualified kidney safety biomarker panel, highlighting Phase 1 and 2 trials for candidate therapeutics in Pfizer's portfolio (PFE-1 and PFE-2, respectively) that induced renal tubular injury in rat toxicity studies. Clusterin (CLU), cystatin-C (CysC), kidney injury molecule-1 (KIM-1), N-acetyl-beta-D-glucosaminidase (NAG), neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin (OPN) were measured in urine samples from i) Phase 1 healthy volunteers (HVs; n = 12) dosed with PFE-1, ii) Phase 2 rheumatoid arthritis patients (RA; n = 266) dosed with PFE-2, iii) lupus patients on standard-of-care therapies (n = 121), and iv) healthy volunteers (n = 60). The FDA-defined composite measure (CM), calculated as the geometric mean response across the 6 biomarkers, was increased ∼30% in HVs administered 100 mg PFE-1 relative to placebo, providing evidence of DIKI. In contrast, the CM for RA patients dosed with PFE-2 was comparable to placebo controls, helping to de-risk the concern for DIKI at clinically relevant doses. Comparing individual biomarker concentrations across disease states revealed that CLU, KIM-1, NAG, NGAL, and OPN are elevated in the urine of RA and lupus patients (those without severe active proliferative lupus nephritis) relative to HVs. Overall, these case studies demonstrate the value of using the FDA-qualified kidney biomarker panel to guide risk assessment, dose selection, and clinical decision making for novel therapeutics, both in HVs and patient populations.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of PF-06817024 in Healthy Participants, Participants with Chronic Rhinosinusitis with Nasal Polyps, and Participants with Atopic Dermatitis: A Phase 1, Randomized, Double-Blind, Placebo-Controlled Study.

PF-06817024 is a high affinity, humanized antibody that binds interleukin-33, a proinflammatory type 2 cytokine, and thereby has the potential to inhibit downstream type 2 inflammation. This Phase 1, randomized, placebo-controlled study was conducted in 3 parts to evaluate the safety, tolerability, pharmacokinetics (PK), immunogenicity, and pharmacodynamics of escalating single and limited repeat PF-06817024 doses in healthy participants (Part 1), a single dose of PF-06817024 in participants with chronic rhinosinusitis with nasal polyps (Part 2), and repeat doses of PF-06817024 in participants with moderate to severe atopic dermatitis (atoptic dermatitis; Part 3). PF-06817024 was generally well tolerated in all participant populations. Most participants experienced a treatment-emergent adverse event (healthy participants, 78.4% and 100%; participants with chronic rhinosinusitis with nasal polyps, 90.9% and 88.9%; and participants with atoptic dermatitis, 60.0% and 62.5% in the PF-06817024 and placebo groups, respectively). No substantial deviations from dose proportionality were observed for single intravenous doses of 10-1000 mg, indicating linear PK in healthy participants. Mean terminal half-life ranged from 83 to 94 days after single intravenous administration in healthy participants and was similar to that observed after administration in the studied patient populations. Incidences of antidrug antibodies in the studied populations were 10.8%, 9.1%, and 5.0% for healthy participants, participants with chronic rhinosinusitis with nasal polyps, and participants with atoptic dermatitis, respectively. In addition, dose-dependent increases were observed in total serum interleukin-33 levels of treated participants, indicating target engagement. Overall, the PK and safety profile of PF-06817024 supports further investigation of the drug as a potential treatment for allergic diseases.

A Phase 1 Study to Assess Mass Balance and Absolute Bioavailability of Zimlovisertib in Healthy Male Participants Using a 14 C-Microtracer Approach.

Zimlovisertib (PF-06650833) is a selective, reversible inhibitor of interleukin-1 receptor-associated kinase 4 (IRAK4) with anti-inflammatory effects. This phase 1, open-label, fixed-sequence, two-period, single-dose study aimed to evaluate the mass balance and excretion rate of zimlovisertib in healthy male participants using a 14 C-microtracer approach. All six participants received 300 mg 14 C-zimlovisertib with lower radioactivity per mass unit orally in Period A, then unlabeled zimlovisertib 300 mg orally and 14 C-zimlovisertib 135 µg intravenously (IV) in Period B. Study objectives included extent and rate of excretion of 14 C-zimlovisertib, pharmacokinetics, and safety and tolerability of oral and IV zimlovisertib. Total radioactivity recovered in urine and feces was 82.4% ± 6.8% (urine 23.1% ± 12.3%, feces 59.3% ± 9.7%) in Period A. Zimlovisertib was absorbed rapidly following oral administration, with the fraction absorbed estimated to be 44%. Absolute oral bioavailability of the 300-mg dose was 17.4% (90% confidence interval 14.1%, 21.5%) using the dose-normalized area under the concentration-time curve from time 0 to infinity. There were no deaths, serious adverse events (AEs), severe AEs, discontinuations or dose reductions due to AEs, and no clinically significant laboratory abnormalities. These results demonstrate that zimlovisertib had low absolute oral bioavailability and low absorption (<50%).

The Interleukin-1 Receptor-Associated Kinase 4 Inhibitor PF-06650833 Blocks Inflammation in Preclinical Models of Rheumatic Disease and in Humans Enrolled in a Randomized Clinical Trial.

OBJECTIVE: To investigate the role of PF-06650833, a highly potent and selective small-molecule inhibitor of interleukin-1-associated kinase 4 (IRAK4), in autoimmune pathophysiology in vitro, in vivo, and in the clinical setting. METHODS: Rheumatoid arthritis (RA) inflammatory pathophysiology was modeled in vitro through 1) stimulation of primary human macrophages with anti-citrullinated protein antibody immune complexes (ICs), 2) RA fibroblast-like synoviocyte (FLS) cultures stimulated with Toll-like receptor (TLR) ligands, as well as 3) additional human primary cell cocultures exposed to inflammatory stimuli. Systemic lupus erythematosus (SLE) pathophysiology was simulated in human neutrophils, dendritic cells, B cells, and peripheral blood mononuclear cells stimulated with TLR ligands and SLE patient ICs. PF-06650833 was evaluated in vivo in the rat collagen-induced arthritis (CIA) model and the mouse pristane-induced and MRL/lpr models of lupus. Finally, RNA sequencing data generated with whole blood samples from a phase I multiple-ascending-dose clinical trial of PF-06650833 were used to test in vivo human pharmacology. RESULTS: In vitro, PF-06650833 inhibited human primary cell inflammatory responses to physiologically relevant stimuli generated with RA and SLE patient plasma. In vivo, PF-06650833 reduced circulating autoantibody levels in the pristane-induced and MRL/lpr murine models of lupus and protected against CIA in rats. In a phase I clinical trial (NCT02485769), PF-06650833 demonstrated in vivo pharmacologic action pertinent to SLE by reducing whole blood interferon gene signature expression in healthy volunteers. CONCLUSION: These data demonstrate that inhibition of IRAK4 kinase activity can reduce levels of inflammation markers in humans and provide confidence in the rationale for clinical development of IRAK4 inhibitors for rheumatologic indications.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of PF-06650833, a selective interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor, in single and multiple ascending dose randomized phase 1 studies in healthy subjects.

BACKGROUND: PF-06650833 is a potent, selective inhibitor of interleukin-1 receptor-associated kinase 4 (IRAK4). Two randomized, double-blind, sponsor-open phase 1 studies evaluated the safety, pharmacokinetics, and pharmacodynamics of single (SAD) and multiple ascending doses (MAD) of PF-06650833 immediate-release (IR) and modified-release (MR) oral formulations in healthy adult subjects. METHODS: Study 1 (NCT02224651) was a 96-day, placebo-substitution, SAD study of once-daily (QD) oral PF-06650833 IR 1 to 6000 mg and MR 30 to 300 mg in fasted and fed states. Study 2 (NCT02485769) was a 14-day, placebo-controlled, MAD study of PF-06650833 IR 25 to 750 mg twice daily, IR 1000 mg four times per day, IR 330 mg three times per day, and MR 300 mg QD. RESULTS: PF-06650833 was generally well tolerated, with no dose-limiting treatment-emergent adverse events (TEAEs) identified in either study. TEAEs were generally mild in severity, with headache, gastrointestinal disorders, and acne most commonly reported. No serious AEs or deaths were reported. A maximum tolerated dose was not established in either study. In the SAD study, food intake delayed absorption of IR 30 mg and increased total exposure by 33%. Delayed absorption was achieved with the MR formulation (Tmax of 1 h versus 8 h for IR 100 mg and MR 100 mg formulations, respectively). Food had no effect on total exposure for MR 30 mg, but reduced half-life 1.8-fold and increased Cmax by 62%. In the MAD study, accumulation ranged from 0.9-fold to 1.4-fold for AUCtau and 0.9-fold to 1.3-fold for Cmax. Less than 1% of the dose was recovered unchanged in urine for all dose groups, with renal clearance ranging from 14 to 23 mL/min for IR < 750 mg and MR 300 mg. There was a sustained decrease in serum high-sensitivity C-reactive protein for IR ≥ 250 mg and MR 300 mg. Based on the cholesterol/hydroxycholesterol ratio, no apparent CYP3A induction or inhibition was observed. CONCLUSIONS: PF-06650833, the first IRAK4 inhibitor to enter clinical development, has a favorable safety and pharmacokinetic profile and has shown evidence of pharmacological effect. The data support continued evaluation in human clinical trials for the treatment of rheumatic and autoimmune diseases. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02224651, registered 25 August 2014; NCT02485769, registered 30 June 2015.

Dissociable effect of acute varenicline on tonic versus cue-provoked craving in non-treatment-motivated heavy smokers.

RATIONALE: The effectiveness of varenicline for smoking cessation has been established, but little is known about the psychological processes that mediate this clinical outcome. OBJECTIVES: This study evaluated the effect of a single dose of varenicline on tonic and cue-provoked changes in craving, withdrawal, and affect using a randomized, double-blind, placebo-controlled, cross-over design. METHODS: Following overnight abstinence, 38 non-treatment-motivated smokers received either varenicline 2mg or matched placebo, then tonic measures of craving, withdrawal, and positive and negative affect were obtained at 30-min intervals. At 4-h post-administration, a cue exposure session obtained the same subjective measures at three time-points following the physical handling of a lit cigarette versus the sharpening and handling of a pencil. RESULTS: At 4-h post-administration, varenicline reduced tonic craving as well as craving across the smoking and neutral cue conditions, relative to placebo. By contrast, the capacity of the smoking cue to enhance craving relative to the neutral cue was unaffected by varenicline. Measures of withdrawal and positive and negative affect produced mixed results. CONCLUSIONS: Acute varenicline selectively attenuates tonic but not cue-provoked craving. This dissociation provides insight into the specific psychological processes that might mediate the effectiveness of varenicline, and highlights cue-provoked craving as a discrete target for advancing smoking cessation pharmacotherapy.