Differential properties of Janus kinase inhibitors in the treatment of immune-mediated inflammatory diseases.

Janus kinases (JAKs) are a family of cytosolic tyrosine kinases that regulate cytokine signal transduction, including cytokines involved in a range of inflammatory diseases, such as RA, psoriasis, atopic dermatitis and IBD. Several small-molecule JAK inhibitors (JAKis) are now approved for the treatment of various immune-mediated inflammatory diseases. There are, however, key differences between these agents that could potentially translate into unique clinical profiles. Each JAKi has a unique chemical structure, resulting in a distinctive mode of binding within the catalytic cleft of the target JAK, and giving rise to distinct pharmacological characteristics. In addition, the available agents have differing selectivity for JAK isoforms, as well as off-target effects against non-JAKs. Other differences include effects on haematological parameters, DNA damage repair, reproductive toxicity and metabolism/elimination. Here we review the pharmacological profiles of the JAKis abrocitinib, baricitinib, filgotinib, peficitinib, tofacitinib and upadacitinib.

Safety profile of upadacitinib in patients at risk of cardiovascular disease: integrated post hoc analysis of the SELECT phase III rheumatoid arthritis clinical programme.

OBJECTIVE: Increased risk of serious adverse events (AEs) was reported for tofacitinib relative to tumour necrosis factor inhibitor therapy in patients with rheumatoid arthritis (RA) aged ≥50 years enriched for cardiovascular (CV) risk (ORAL Surveillance). We assessed post hoc the potential risk of upadacitinib in a similar RA population. METHODS: Pooled safety data from six phase III trials were evaluated post hoc for AEs in patients receiving upadacitinib 15 mg once a day (with or without conventional synthetic disease-modifying antirheumatic drugs), adalimumab 40 mg every other week with concomitant methotrexate (MTX), or MTX monotherapy in the overall trial population and in a subset of patients with higher CV risk (aged ≥50 years, ≥1 CV risk factor). Higher-risk patients from a head-to-head study of upadacitinib 15 mg versus adalimumab (SELECT-COMPARE) were assessed in parallel. Exposure-adjusted incidence rates for treatment-emergent AEs were summarised based on exposure to upadacitinib or comparators. RESULTS: A total of 3209 patients received upadacitinib 15 mg, 579 received adalimumab and 314 received MTX monotherapy; ~54% of the patients were included in the overall and SELECT-COMPARE higher-risk populations. Major adverse cardiovascular events (MACE), malignancy (excluding non-melanoma skin cancer (NMSC)) and venous thromboembolism (VTE) were more frequent in the higher-risk cohorts versus the overall population but were generally similar across treatment groups. Rates of serious infections in higher-risk populations and herpes zoster (HZ) and NMSC in all populations were higher with upadacitinib 15 mg than comparators. CONCLUSIONS: An increased risk of MACE, malignancy (excluding NMSC) and VTE was observed in higher-risk populations with RA, yet risk was comparable between upadacitinib-treated and adalimumab-treated patients. Higher rates of NMSC and HZ were observed with upadacitinib versus comparators across all populations, and increased rates of serious infections were detected in upadacitinib-treated patients at higher CV risk. TRIAL REGISTRATION NUMBERS: NCT02706873, NCT02675426, NCT02629159, NCT02706951, NCT02706847 and NCT03086343.

Opportunistic infections associated with Janus kinase inhibitor treatment for rheumatoid arthritis: A structured literature review.

BACKGROUND: The availability of Janus kinase (JAK) inhibitors has transformed the management of rheumatoid arthritis (RA), helping patients achieve clinical remission. However, the emergence of opportunistic infections (OIs) associated with the use of JAK inhibitors has been reported. This structured literature review was conducted to summarize reports of OIs associated with JAK inhibitor treatment for RA in clinical trials. METHODS: Structured searches were performed in MEDLINE® and Embase® to identify relevant clinical trial data through March 2021. Bibliographic searches of recent reviews were also conducted, and gray literature searches were used to supplement key gap areas. Publications were screened, extracted, and quality assessed. Data were narratively synthesized. RESULTS: Following screening, 105 publications describing 62 unique clinical trials reporting the rates of OIs in RA patients treated with JAK inhibitors were included. Overall, the highest exposure-adjusted incidence rate was reported for herpes zoster (HZ) infection (any form), followed by OI (any) and tuberculosis based on limited data from clinical trials with approved doses of JAK inhibitors. Lack of head-to-head trials and differences in trial design preclude direct comparison across JAK inhibitors. Higher rates of OIs were noted in the Asian and Australian populations compared with the global population. Higher rates of OIs were also noted with increasing dose of JAK inhibitors in most clinical trial data. CONCLUSIONS: HZ was the most common OI reported among RA patients using all currently approved JAK inhibitors in clinical trials, although tuberculosis and other OIs were also reported. More long-term safety studies in the real-world setting are needed to compare the risk of OIs between various JAK inhibitors.

Incidence Rates of Interstitial Lung Disease Events in Tofacitinib-Treated Rheumatoid Arthritis Patients: Post Hoc Analysis From 21 Clinical Trials.

BACKGROUND/OBJECTIVE: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). Interstitial lung disease (ILD) is an extra-articular manifestation of RA. We investigated incidence rates of ILD in patients with RA, receiving tofacitinib 5 or 10 mg twice daily, and identified potential risk factors for ILD. METHODS: This post hoc analysis comprised a pooled analysis of patients receiving tofacitinib 5 or 10 mg twice daily or placebo from 2 phase (P)1, 10 P2, 6 P3, 1 P3b/4, and 2 long-term extension studies. Interstitial lung disease events were adjudicated as "probable" (supportive clinical evidence) or "possible" (no supportive clinical evidence) compatible adverse events. Incidence rates (patients with events per 100 patient-years) were calculated for ILD events. RESULTS: Of 7061 patients (patient-years of exposure = 23,393.7), 42 (0.6%) had an ILD event; median time to ILD event was 1144 days. Incidence rates for ILD with both tofacitinib doses were 0.18 per 100 patient-years. Incidence rates generally remained stable over time. There were 17 of 42 serious adverse events (40.5%) of ILD; for all ILD events (serious and nonserious), 35 of 42 events (83.3%) were mild to moderate in severity. A multivariable Cox regression analysis identified age 65 years or older (hazard ratio 2.43 [95% confidence interval, 1.13-5.21]), current smokers (2.89 [1.33-6.26]), and Disease Activity Score in 28 joints-erythrocyte sedimentation rate score (1.30 [1.04-1.61]) as significant risk factors for ILD events. CONCLUSIONS: Across P1/2/3/4/long-term extension studies, incidence rates for ILD events were 0.18 following tofacitinib treatment, and ILD events were associated with known risk factors for ILD in RA.

Assessment of radiographic progression in patients with rheumatoid arthritis treated with tofacitinib in long-term studies.

OBJECTIVES: Tofacitinib is an oral Janus kinase inhibitor for the treatment of RA. We evaluated radiographic progression in tofacitinib-treated patients with RA for up to 3 years in two pooled long-term extension (LTE) studies (ORAL Sequel; A3921041) (primary analysis), and for up to 5 years using data integrated from one phase (P)2 (A3921068), two P3 (ORAL Start; ORAL Scan) and two LTE studies (exploratory analysis). METHODS: In LTE studies, patients received tofacitinib 5 mg twice daily (BID) or 10 mg BID as monotherapy or with conventional synthetic (cs)DMARDs. Radiographic outcomes up to 3 years: least squares mean (LSM) change from baseline in van der Heijde modified Total Sharp Score (ΔmTSS), erosion score (ΔES) and joint space narrowing (ΔJSN) score; proportion of patients with no radiographic progression (ΔmTSS ≤0.5); proportion of patients with no new erosions (ΔES ≤0.5). ΔmTSS was evaluated for up to 5 years in an exploratory analysis. RESULTS: For all tofacitinib-treated patients with radiographic data available at LTE month 36 (n = 414), LSM ΔmTSS was 1.14, LSM ΔES was 0.66, LSM ΔJSN was 0.74, and 74.3% and 86.2% of patients showed no radiographic progression and no new erosions, respectively. Similar values were observed regardless of tofacitinib dose, or whether patients received tofacitinib as monotherapy or with csDMARDs. In an exploratory analysis of integrated P2/P3/LTE studies, LSM ΔmTSS was 3.34 at month 60 (n = 269). CONCLUSION: Limited progression of structural damage was observed in tofacitinib-treated patients up to 5 years, with similar results for tofacitinib used as monotherapy or combination therapy up to 3 years. TRIAL REGISTRATION: ClinicalTrials.gov (http://clinicaltrials.gov): NCT01164579; NCT01039688; NCT00847613; NCT00413699; NCT00661661.

Safety and efficacy of tofacitinib for up to 9.5 years in the treatment of rheumatoid arthritis: final results of a global, open-label, long-term extension study.

BACKGROUND: Final data are presented for the ORAL Sequel long-term extension (LTE) study evaluating the safety and efficacy of tofacitinib 5 mg and 10 mg twice daily (BID) for up to 9.5 years in patients with rheumatoid arthritis (RA). METHODS: Eligible patients had previously completed a phase 1, 2, or 3 qualifying index study of tofacitinib and received open-label tofacitinib 5 mg or 10 mg BID. Stable background therapy, including csDMARDs, was continued; adjustments to tofacitinib or background therapy were permitted at investigators' discretion. Assignment to dose groups (5 mg or 10 mg BID) was based on patients' average total daily dose. The primary objective was to determine the long-term safety and tolerability of tofacitinib 5 mg and 10 mg BID; the key secondary objective was to evaluate the long-term persistence of efficacy. RESULTS: Between February 5, 2007, and November 30, 2016, 4481 patients were enrolled. Total tofacitinib exposure was 16,291 patient-years. Safety data are reported up to month 114 for all tofacitinib; efficacy data are reported up to month 96 for tofacitinib 5 mg BID and month 72 for 10 mg BID (with low patient numbers limiting interpretation beyond these time points). Overall, 52% of patients discontinued (24% due to adverse events [AEs] and 4% due to insufficient clinical response); the safety profile remained consistent with that observed in prior phase 1, 2, 3, or LTE studies. The incidence rate (IR; number of patients with events per 100 patient-years) for AEs leading to discontinuation was 6.8. For all-cause AEs of special interest, IRs were 3.4 for herpes zoster, 2.4 for serious infections, 0.8 for malignancies excluding non-melanoma skin cancer, 0.4 for major adverse cardiovascular events, and 0.3 for all-cause mortality. Clinically meaningful improvements in the signs and symptoms of RA and physical functioning, which were observed in the index studies, were maintained. CONCLUSIONS: Tofacitinib 5 mg and 10 mg BID demonstrated a consistent safety profile (as monotherapy or combination therapy) and sustained efficacy in this open-label LTE study of patients with RA. Safety data are reported up to 9.5 years, and efficacy data up to 8 years, based on adequate patient numbers to support conclusions. TRIAL REGISTRATION: NCT00413699 , funded by Pfizer Inc (date of trial registration: December 20, 2006).

Evaluation of the Short-, Mid-, and Long-Term Effects of Tofacitinib on Lymphocytes in Patients With Rheumatoid Arthritis.

OBJECTIVE: Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). Altered lymphocyte cell counts and a potential association with increased infection rates have been reported in RA patients treated with JAK inhibitors. This analysis was undertaken to evaluate the short-, mid-, and long-term effects of tofacitinib on lymphocytes and infection rates in patients with RA. METHODS: In this post hoc analysis, absolute lymphocyte counts (ALCs) were obtained from phase III studies (12-24 months; n = 717-958) and phase I/II/III/long-term extension studies of tofacitinib (≤117 months) (All RA population; n = 7,061); lymphocyte subset counts (LSCs) were from phase II studies (1.5-6 months' exposure; n = 236-486), an ORAL Sequel vaccine substudy (~22 months; n = 198), and an ORAL Sequel lymphocyte substudy (~50 months; n = 55-1,035) of tofacitinib. The reversibility of ALC/LSC changes was evaluated. The relationship of ALC and LSC to infections was analyzed in the All RA population. The value of monitoring ALC alone was assessed by examining correlations between ALCs and LSCs. RESULTS: Tofacitinib treatment resulted in an initial increase in ALC versus pretreatment baseline, which gradually declined to steady state by ~48 months. CD4+ and CD8+ T cell counts decreased over long-term treatment, and ALC and LSC changes were reversible upon treatment cessation. Patients with ALCs of <500 cells/mm3 had an increased risk of serious infections. There was no strong association between CD4+ T cell, CD8+ T cell, B cell, or natural killer cell counts and serious infection incidence rates. ALC and CD4+ or CD8+ T cell counts correlated well (R = 0.65-0.86). CONCLUSION: Our findings indicate that monitoring of ALC alone appears to be adequate to assess infection risk in tofacitinib-treated patients with RA.

Assessments of the unmet need in the management of patients with rheumatoid arthritis: analyses from the NOR-DMARD registry.

OBJECTIVE: To describe the outcomes of MTX and biologic DMARD (bDMARD) treatment in patients with RA and assess unmet needs in patients who fail treatment, using real-world data from the Norwegian DMARD (NOR-DMARD) registry. METHODS: Data included RA treatment courses from January 2007 until July 2016. Patients received MTX monotherapy (in MTX-naïve patients), bDMARD monotherapy, bDMARDs + MTX, or bDMARDs + other conventional synthetic DMARDs (csDMARDs). DAS28-4(ESR) was used to measure remission (<2.6) and inadequate response (>3.2) across all groups at Months 6 and 12. Estimated ACR20/50/70 and EULAR good and good/moderate response rates (based on DAS28-4[ESR] score) for bDMARDs were modelled at Months 6 and 12 using logistic mixed regression. DAS28-4(ESR) scores and changes from baseline, and rates and reasons for discontinuation, were evaluated for all groups over 24 months. RESULTS: The 2778 treatment courses in this analysis included 714 MTX monotherapy, 396 bDMARD monotherapy, 1460 bDMARDs + MTX and 208 bDMARDs + other csDMARDs. Of patients with DAS28-4(ESR) data at Months 6 and 12 (25.0-34.1%), 33.9-47.2% did not switch treatment and were inadequate-responders at Month 12. There were no significant differences in efficacy between bDMARD groups (bDMARD monotherapy, or bDMARDs + MTX or other csDMARDs). Lack of efficacy was the most common reason for stopping treatment across all groups (13.7-22.1% over 24 months). CONCLUSION: An unmet treatment need exists for patients still experiencing inadequate response to MTX monotherapy and bDMARDs as monotherapy or in combination with MTX/other csDMARDs after 12 months. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT01581294.

Use of a risk characterisation approach to contextualise the safety profile of new rheumatoid arthritis treatments: a case study using tofacitinib.

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). To characterise the relative safety profile of tofacitinib to biologic disease-modifying antirheumatic drugs (bDMARDs), the accrued patient-years (pt-yrs) of exposure needed in an RA clinical trial programme to detect a potential increase in risk of specific adverse events (AEs) was determined. This case study/framework was constructed on the pt-yrs' accrual within pooled phase (P)1, P2 and P3, as well as long-term extension, studies of tofacitinib in RA (March 2015 data-cut) and published AE incidence rates for bDMARDs. Sample size calculations were based on a Poisson distribution to estimate pt-yrs' exposure required for 90 % probability that the lower bound of the 95 % confidence interval for tofacitinib/bDMARD would be >1, assuming that tofacitinib rates were 1.2×/1.5×/2.0× greater than comparator rates. AE rates for bDMARDs were derived from sources intended to optimise similarity with the tofacitinib database in terms of baseline characteristics, study duration and follow-up. Based on the tofacitinib exposure accrued (19,406 pt-yrs), data were sufficient (90 % probability) to detect potential differences over external bDMARD comparator rates in serious infections (≥1.2×), malignancies (excluding non-melanoma skin cancer [NMSC]), NMSC, major adverse cardiovascular events (MACE) and lymphoma (each ≥1.5×), as well as opportunistic infections and gastrointestinal perforations (≥2×), should they exist. This risk characterisation approach can support the comparative safety of new RA medications. To date, tofacitinib safety appears similar to approved published data from bDMARDs with respect to serious infections, malignancies (excluding NMSC), NMSC, MACE, lymphoma, opportunistic infections and gastrointestinal perforations.

Is radiographic progression in modern rheumatoid arthritis trials still a robust outcome? Experience from tofacitinib clinical trials.

BACKGROUND: The detection of statistically significant reductions in radiographic progression during clinical studies in patients with rheumatoid arthritis (RA) has become increasingly difficult over the past decade due to early-escape study designs and declining rates of progression in control-group patients. We investigated the impact of extremes of radiographic data (outliers) and baseline prognostic factors on detection of treatment effects, to provide guidance on future analysis of joint structural data in RA clinical trials. METHODS: Data were from two, phase 3, randomized, double-blind, placebo-controlled trials of tofacitinib in adult patients with moderate to severe RA: ORAL Scan (NCT00847613) and ORAL Start (NCT01039688). These studies detected significant reductions in radiographic progression with tofacitinib 10 mg twice daily (BID) plus background methotrexate (ORAL Scan), and with tofacitinib 5 or 10 mg BID as monotherapy (ORAL Start). We evaluated mean changes from baseline in van der Heijde modified total Sharp score (mTSS) at month 6 and month 12, using analysis of covariance (ANCOVA). A trimmed analysis was used to deal with extremes of data. The impact of baseline prognostic factors on radiographic progression was evaluated using ANCOVA to analyze the mean change from baseline in mTSS for each factor in turn. RESULTS: The analysis included data from 720 patients from ORAL Scan and 880 patients from ORAL Start. Trimmed analyses were unbiased for the true mean estimate and enabled us to remove the effect of influential extreme observations in the data set. Almost all patients had at least one poor prognostic factor at baseline (e.g., high level of disease activity, or positive for rheumatoid factor). The strongest predictor of treatment effect was the severity of radiographic damage at baseline. CONCLUSIONS: A trimmed analysis can establish whether any significant inhibition of structural damage is being driven by extremes of data, and should be one of the sensitivity analyses of choice for structural data in RA clinical trials. Furthermore, analysis of radiographic data based on baseline prognostic factors may reveal increased treatment effects. Application of these methods to analysis of radiographic data from clinical trials in patients with RA, allows a more complete interpretation of data. TRIAL REGISTRATION: Clinicaltrials.gov NCT00847613 (registered 17 February 2009) and NCT01039688 (registered 23 December 2009).