Assessment of the Effects of Inhibition or Induction of CYP2C19 and CYP2C9 Enzymes, or Inhibition of OAT3, on the Pharmacokinetics of Abrocitinib and Its Metabolites in Healthy Individuals.

BACKGROUND AND OBJECTIVE: Abrocitinib is a Janus kinase 1-selective inhibitor for the treatment of moderate-to-severe atopic dermatitis. Abrocitinib is eliminated primarily by metabolism involving cytochrome P450 (CYP) enzymes. Abrocitinib pharmacologic activity is attributable to the unbound concentrations of the parent molecule and 2 active metabolites, which are substrates of organic anion transporter 3 (OAT3). The sum of potency-adjusted unbound exposures of abrocitinib and its 2 active metabolites is termed the abrocitinib active moiety. We evaluated effects of CYP inhibition, CYP induction, and OAT3 inhibition on the pharmacokinetics of abrocitinib, its metabolites, and active moiety. METHODS: Three fixed-sequence, open-label, phase I studies in healthy adult volunteers examined the drug-drug interactions (DDIs) of oral abrocitinib with fluvoxamine and fluconazole, rifampin, and probenecid. RESULTS: Co-administration of abrocitinib with fluvoxamine or fluconazole increased the area under the plasma concentration-time curve from time 0 to infinity (AUCinf) of the unbound active moiety of abrocitinib by 91% and 155%, respectively. Co-administration with rifampin decreased the unbound active moiety AUCinf by 56%. The OAT3 inhibitor probenecid increased the AUCinf of the unbound active moiety by 66%. CONCLUSIONS: It is important to consider the effects of DDIs on the abrocitinib active moiety when making dosing recommendations. Co-administration of strong CYP2C19/2C9 inhibitors or CYP inducers impacted exposure to the abrocitinib active moiety. A dose reduction by half is recommended if abrocitinib is co-administered with strong CYP2C19 inhibitors, whereas co-administration with strong CYP2C19/2C9 inducers is not recommended. No dose adjustment is required when abrocitinib is administered with OAT3 inhibitors. CLINICAL TRIALS REGISTRATION IDS: NCT03634345, NCT03637790, NCT03937258.

Tofacitinib in juvenile idiopathic arthritis: a double-blind, placebo-controlled, withdrawal phase 3 randomised trial.

BACKGROUND: Tofacitinib is an oral Janus kinase inhibitor. This trial assessed the efficacy and safety of tofacitinib versus placebo in patients with polyarticular course juvenile idiopathic arthritis (JIA). METHODS: This double-blind, withdrawal phase 3 trial enrolled patients with polyarticular course JIA (extended oligoarthritis, rheumatoid factor-positive or rheumatoid factor-negative polyarthritis, or systemic JIA without active systemic features) aged 2 years to younger than 18 years, and was done at 64 centres of the Paediatric Rheumatology International Trials Organisation and Pediatric Rheumatology Collaborative Study Group networks in 14 countries. Patients with psoriatic arthritis or enthesitis-related arthritis were enrolled for exploratory endpoints. During part 1 of the study, patients received oral open-label tofacitinib (weight-based doses; 5 mg twice daily or lower) for 18 weeks. Patients achieving at least JIA/American College of Rheumatology 30 response were randomly assigned (1:1) using an Interactive Response Technology system to continue tofacitinib or switch to placebo in part 2 of the study for 26 weeks. The primary endpoint was JIA flare rate by week 44 in part 2 in patients with polyarticular course JIA; the intention-to-treat principle was applied. Safety was evaluated throughout part 1 and part 2 of the study in all patients who received one dose or more of study medication. This trial is registered with ClinicalTrials.gov, NCT02592434. FINDINGS: Between June 10, 2016, and May 16, 2019, of 225 patients enrolled, 184 (82%) patients had polyarticular course JIA, 20 (9%) had psoriatic arthritis, and 21 (9%) had enthesitis-related arthritis. 147 (65%) of 225 patients received concomitant methotrexate. In part 2, 142 patients with polyarticular course JIA were assigned to tofacitinib (n=72) or placebo (n=70). Flare rate by week 44 was significantly lower with tofacitinib (21 [29%] of 72 patients) than with placebo (37 [53%] of 70 patients; hazard ratio 0·46, 95% CI 0·27-0·79; p=0·0031). In part 2 of the study, adverse events occurred in 68 (77%) of 88 patients receiving tofacitinib and 63 (74%) of 85 in the placebo group. Serious adverse events occurred in one (1%) and two (2%), respectively. In the entire tofacitinib exposure period, 107 (48%) of 225 patients had infections or infestations. There were no deaths during this study. INTERPRETATION: The results of this pivotal trial show that tofacitinib is an effective treatment in patients with polyarticular course JIA. New oral therapies are particularly relevant for children and adolescents, who might prefer to avoid injections. FUNDING: Pfizer.

Tofacitinib in the treatment of Indian patients with rheumatoid arthritis: A post hoc analysis of efficacy and safety in Phase 3 and long-term extension studies over 7 years.

OBJECTIVES: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We characterized tofacitinib efficacy/safety in Indian vs rest of the world (ROW; excluding India) RA patients. METHODS: Efficacy data were pooled for disease-modified antirheumatic drug (DMARD) inadequate responders from Phase (P)3 studies. For Indian patients, ORAL Solo and ORAL Scan; ROW (excluding India), these studies plus ORAL Step, ORAL Sync, and ORAL Standard. Safety data also included ORAL Start (P3; methotrexate-naïve) and ORAL Sequel (long-term extension [LTE] study; data cut-off March 2017) for Indian patients, and these studies plus A3921041 (LTE study; Japanese study) for ROW. Efficacy outcomes at months 3/6: American College of Rheumatology (ACR)20/50/70; Disease Activity Score in 28 joints, erythrocyte sedimentation rate remission/low disease activity; change from baseline in Health Assessment Questionnaire-Disability Index. Incidence rates (IRs; patients with events/100 patient-years) for adverse events of special interest (AESIs) were assessed throughout. Descriptive data underwent no formal comparison. RESULTS: One-hundred-and-ninety-seven Indian and 3879 ROW patients were included. Compared with ROW patients, Indian patients were younger, had lower body mass index, shorter RA duration, and higher baseline disease activity; most Indian patients were non-smokers and all were biologic DMARD (bDMARD)-naïve. Month 3 ACR20 rates with tofacitinib 5 mg twice daily/10 mg twice daily/placebo were 67.4%/82.1%/40.9% (India) and 59.0%/66.1%/28.2% (ROW), and month 6 rates were 76.2%/92.1%/88.9% (India) and 69.0%/74.2%/66.5% (ROW). Month 3/6 improvements in other outcomes were generally numerically greater with tofacitinib vs placebo, and similar in both populations. Compared with ROW, Indian patients had numerically fewer AEs/serious AEs, and similar IRs for discontinuations due to AEs and AESIs, except that tuberculosis (TB) IR was higher in Indian (IR = 1.21; 95% CI 0.49, 2.49) vs ROW patients (IR = 0.17; 95% CI 0.11, 0.25). CONCLUSIONS: Tofacitinib efficacy/safety were similar in both populations, except TB IR, which was higher in Indian patients but in line with those in bDMARD-treated RA patients from high-risk countries (IR = 0.00-2.56; TB IR >0.05 [World Health Organization]). Limitations included the small Indian population and baseline differences between populations.

Reversibility of peripheral blood leukocyte phenotypic and functional changes after exposure to and withdrawal from tofacitinib, a Janus kinase inhibitor, in healthy volunteers.

This study evaluated the short-term effects of tofacitinib treatment on peripheral blood leukocyte phenotype and function, and the reversibility of any such effects following treatment withdrawal in healthy volunteers. Cytomegalovirus (CMV)-seropositive subjects received oral tofacitinib 10 mg twice daily for 4 weeks and were followed for 4 weeks after drug withdrawal. There were slight increases in total lymphocyte and total T-cell counts during tofacitinib treatment, and B-cell counts increased by up to 26%. There were no significant changes in granulocyte or monocyte counts, or granulocyte function. Naïve and central memory T-cell counts increased during treatment, while all subsets of activated T cells were decreased by up to 69%. T-cell subsets other than effector memory cluster of differentiation (CD)4+, activated naïve CD4+ and effector CD8+ T-cell counts and B-cell counts, normalized 4 weeks after withdrawal. Following ex vivo activation, measures of CMV-specific T-cell responses, and antigen non-specific T-cell-mediated cytotoxicity and interferon (IFN)-γ production, decreased slightly. These T-cell functional changes were most pronounced at Day 15, partially normalized while still on tofacitinib and returned to baseline after drug withdrawal. Total natural killer (NK)-cell counts decreased by 33%, returning towards baseline after drug withdrawal. NK-cell function decreased during tofacitinib treatment, but without a consistent time course across measured parameters. However, markers of NK-cell-mediated cytotoxicity, antibody-dependent cellular cytotoxicity and IFN-γ production were decreased up to 42% 1 month after drug withdrawal. CMV DNA was not detectable in whole blood, and there were no cases of herpes zoster reactivation. No new safety concerns arose. In conclusion, the effect of short-term tofacitinib treatment on leukocyte composition and function in healthy CMV+ volunteers is modest and largely reversible 4 weeks after withdrawal.

The Safety and Immunogenicity of Live Zoster Vaccination in Patients With Rheumatoid Arthritis Before Starting Tofacitinib: A Randomized Phase II Trial.

OBJECTIVE: Patients with rheumatoid arthritis (RA) are at increased risk of herpes zoster, and vaccination is recommended for patients ages 50 years and older, prior to starting treatment with biologic agents or tofacitinib. Tofacitinib is an oral JAK inhibitor for the treatment of RA. We evaluated its effect on the immune response and safety of live zoster vaccine (LZV). METHODS: In this phase II, 14-week, placebo-controlled trial, patients ages 50 years and older who had active RA and were receiving background methotrexate were given LZV and randomized to receive tofacitinib 5 mg twice daily or placebo 2-3 weeks postvaccination. We measured humoral responses (varicella zoster virus [VZV]-specific IgG level as determined by glycoprotein enzyme-linked immunosorbent assay) and cell-mediated responses (VZV-specific T cell enumeration, as determined by enzyme-linked immunospot assay) at baseline and 2 weeks, 6 weeks, and 14 weeks postvaccination. End points included the geometric mean fold rise (GMFR) in VZV-specific IgG levels (primary end point) and T cells (number of spot-forming cells/106 peripheral blood mononuclear cells) at 6 weeks postvaccination. RESULTS: One hundred twelve patients were randomized to receive tofacitinib (n = 55) or placebo (n = 57). Six weeks postvaccination, the GMFR in VZV-specific IgG levels was 2.11 in the tofacitinib group and 1.74 in the placebo group, and the VZV-specific T cell GMFR was similar in the tofacitinib group and the placebo group (1.50 and 1.29, respectively). Serious adverse events occurred in 3 patients in the tofacitinib group (5.5%) and 0 patients (0.0%) in the placebo group. One patient, who lacked preexisting VZV immunity, developed cutaneous vaccine dissemination 2 days after starting tofacitinib (16 days postvaccination). This resolved after tofacitinib was discontinued and the patient received antiviral treatment. CONCLUSION: Patients who began treatment with tofacitinib 2-3 weeks after receiving LZV had VZV-specific humoral and cell-mediated immune responses to LZV similar to those in placebo-treated patients. Vaccination appeared to be safe in all of the patients except 1 patient who lacked preexisting VZV immunity.

A phase 2 open-label safety and immunogenicity study of a meningococcal B bivalent rLP2086 vaccine in healthy adults.

BACKGROUND: Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis and septicemia in adolescents and young adults. No currently licensed and available vaccine has been shown to provide broad protection against endemic MnB disease. A bivalent rLP2086 vaccine based on two factor H-binding proteins (fHBPs) has been developed to provide broad protection against MnB disease-causing strains. METHODS: This study assessed the safety and immunogenicity of the final formulation of a bivalent rLP2086 vaccine in 60 healthy adults (18-40 years of age) receiving 120 µg doses at 0, 1, and 6 months. Safety was assessed by collecting solicited reactogenicity data and participant-reporting of adverse events. Immunogenicity was evaluated by human serum bactericidal assay (hSBA) against 5 MnB strains expressing distinct fHBP variants and fHBP-specific immunoglobulin G titre. RESULTS: After each immunisation, local reactions such as pain at the injection site and erythema were generally mild or moderate. The most common vaccine-related adverse event was upper respiratory tract infection, which was reported by two participants. Seroprotection (hSBA titres ≥ 1:4) was achieved in 94.3% of participants against a MnB strain expressing the vaccine-homologous fHBP variant A05 and 70.0%-94.7% against MnB strains expressing the heterologous fHBP variants B02, A22, B44, and B24. Seroconversion rates (≥ 4-fold rise in hSBA titres) ranged from 70.0% to 94.7% across the five MnB test strains following the 3-dose vaccination regimen. Immunogenicity responses tended to increase upon subsequent vaccine doses. CONCLUSIONS: Bivalent rLP2086 is a promising vaccine candidate for broad protection against MnB disease-causing strains.