R. Riese

Tofacitinib in Combination With Nonbiologic Disease-Modifying Antirheumatic Drugs in Patients With Active Rheumatoid Arthritis: A Randomized Trial

BACKGROUND Many patients with rheumatoid arthritis (RA) do not achieve adequate and safe responses with disease-modifying antirheumatic drugs (DMARDs). Tofacitinib is a novel, oral, Janus kinase inhibitor that treats RA. OBJECTIVE To evaluate the efficacy and safety of tofacitinib in combination with nonbiologic DMARDs. DESIGN 1-year, double-blind, randomized trial (ClinicalTrials.gov: NCT00856544). SETTING 114 centers in 19 countries. PATIENTS 792 patients with active RA despite nonbiologic DMARD therapy. INTERVENTION Patients were randomly assigned 4:4:1:1 to oral tofacitinib, 5 mg or 10 mg twice daily, or placebo advanced to tofacitinib, 5 mg or 10 mg twice daily. MEASUREMENTS Primary end points were 20% improvement in American College of Rheumatology (ACR20) criteria; Disease Activity Score for 28-joint counts based on the erythrocyte sedimentation rate (DAS28-4[ESR]) of less than 2.6; DAS28-4(ESR)-defined remission, change in Health Assessment Questionnaire Disability Index (HAQ-DI) score, and safety assessments. RESULTS Mean treatment differences for ACR20 response rates (month 6) for the 5-mg and 10-mg tofacitinib groups compared with the combined placebo groups were 21.2% (95% CI, 12.2% to 30.3%; P < 0.001) and 25.8% (CI, 16.8% to 34.8%; P < 0.001), respectively. The HAQ-DI scores (month 3) and DAS28-4(ESR) less than 2.6 response rates (month 6) were also superior in the tofacitinib groups versus placebo. The incidence rates of serious adverse events for patients receiving 5-mg tofacitinib, 10-mg tofacitinib, or placebo were 6.9, 7.3, or 10.9 events per 100 patient-years of exposure, respectively. In the tofacitinib groups, 2 cases of tuberculosis, 2 cases of other opportunistic infections, 3 cardiovascular events, and 4 deaths occurred. Neutrophil counts decreased, hemoglobin and low- and high-density lipoprotein cholesterol levels increased, and serum creatinine levels had small increases in the tofacitinib groups. LIMITATIONS Placebo groups were smaller and of shorter duration. Patients received primarily methotrexate. The ability to assess drug combinations other than tofacitinib plus methotrexate was limited. CONCLUSION Tofacitinib improved disease control in patients with active RA despite treatment with nonbiologic DMARDs, primarily methotrexate. PRIMARY FUNDING SOURCE Pfizer.

Herpes Zoster and Tofacitinib Therapy in Patients With Rheumatoid Arthritis

Patients with rheumatoid arthritis (RA) are at increased risk for herpes zoster (HZ) (i.e., shingles). The aim of this study was to determine whether treatment with tofacitinib increases the risk of HZ in patients with RA.

Safety and Efficacy of Tofacitinib, an Oral Janus Kinase Inhibitor, for the Treatment of Rheumatoid Arthritis in Open-label, Longterm Extension Studies

Objective. To describe the longterm safety and efficacy profile of tofacitinib in patients with moderate to severe active rheumatoid arthritis (RA). Methods. Data were pooled from 2 open-label studies (NCT00413699, NCT00661661) involving patients who had participated in qualifying phase I, II, or III index studies of tofacitinib. Safety data included over 60 months of observation; efficacy data are reported up to Month 48. Treatment was initiated with tofacitinib 5 or 10 mg twice daily. Primary endpoints were adverse events (AE) and laboratory safety data. Secondary endpoints included American College of Rheumatology (ACR) response rates, and Disease Activity Score (28 joints) (DAS28)-4[erythrocyte sedimentation rate (ESR)] and Health Assessment Questionnaire-Disability Index (HAQ-DI) assessments. Results. Overall, 4102 patients were treated for 5963 patient-years; mean (maximum) treatment duration was 531 (1844) days; 20.8% of patients discontinued treatment over 60 months. The most common AE were nasopharyngitis (12.7%) and upper respiratory tract infection (10.5%). Serious AE were reported in 15.4% of patients with an exposure-estimated incidence rate of 11.1 events/100 patient-years. Serious infections were reported in 4.5% of patients with an exposure-estimated incidence rate of 3.1 events/100 patient-years (95% CI: 2.66–3.55). Mean values for laboratory variables were stable over time and consistent with phase II and III studies. Persistent efficacy was demonstrated through Month 48, as measured by ACR response rate (ACR20/50/70) DAS28-4-ESR, and HAQ-DI. Safety and efficacy were similar for patients receiving tofacitinib as monotherapy or with background nonbiologic disease-modifying antirheumatic drugs. Conclusion. Tofacitinib demonstrated consistent safety and persistent efficacy over 48 months in patients with RA.

Inhibition of JAK kinases in patients with rheumatoid arthritis: scientific rationale and clinical outcomes.

CP-690,550 is an orally active and selective inhibitor of the janus kinase (JAK) molecules. The molecular pathways through which the JAK moieties function are described along with the clinical mechanisms associated with their inhibition. Animal models of JAK inhibition are reviewed as a background for the possible inhibition of JAK in humans. The pharmacokinetics of CP-690,550 in humans is described, and the Phase IIA and IIB trials are reviewed in some detail. These trials were dose-ranging and showed a general dose response with relatively robust American College of Rheumatology 20 (ACR20) responses. A proof-of-concept 6-week trial in which CP-690,550 was given as monotherapy was associated with highly efficacious responses at the mid and higher twice-daily dose ranges employed. A subsequent 24 week dose-ranging trial in which CP-690,550 was administered in combination with methotrexate showed ACR20 responses, which were also statistically significant versus placebo interventions. CP-690,550 treatment was associated with side effects, which included headache and nausea. Infections were more common versus placebo as were elevations in transaminase enzymes when administered in combination with methotrexate, and increases in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol. Decreases in haemoglobin and white blood cell (WBC) counts were also observed along with small increases in serum creatinine. Occasional significant decreases of haemoglobin (>2 g dl(-1)) were observed, although decreases of WBC to less than 1000 per mm(3) were not seen. Plans for long-term follow-up of the described trials are described along with the features of five presently ongoing Phase III trials of the CP-690,550 janus kinase (JAK) inhibitor. Future directions include completion and publication of these trials along with study of JAK inhibition for other indications.

Potential Mechanisms Leading to the Abnormal Lipid Profile in Patients With Rheumatoid Arthritis Versus Healthy Volunteers and Reversal by Tofacitinib

Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). Systemic inflammation is proposed to play a fundamental role in the altered lipid metabolism associated with RA; however, the underlying mechanisms are unknown. We undertook this study to compare cholesterol and lipoprotein kinetics in patients with active RA with those in matched healthy volunteers.

Analysis of Infections and All-Cause Mortality in Phase II, Phase III, and Long-Term Extension Studies of Tofacitinib in Patients With Rheumatoid Arthritis†

To determine the rate of infection and all‐cause mortality across tofacitinib phase II, phase III, and long‐term extension (LTE) studies in patients with moderately to severely active rheumatoid arthritis (RA).

Tofacitinib, an oral Janus kinase inhibitor: analysis of malignancies across the rheumatoid arthritis clinical development programme

Objectives Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). To further assess the potential role of Janus kinase inhibition in the development of malignancies, we performed an integrated analysis of data from the tofacitinib RA clinical development programme. Methods Malignancy data (up to 10 April 2013) were pooled from six phase II, six Phase III and two long-term extension (LTE) studies involving tofacitinib. In the phase II and III studies, patients with moderate-to-severe RA were randomised to various tofacitinib doses as monotherapy or with background non-biological disease-modifying antirheumatic drugs (DMARDs), mainly methotrexate. The LTE studies (tofacitinib 5 or 10 mg twice daily) enrolled patients from qualifying prior phase I, II and III index studies. Results Of 5671 tofacitinib-treated patients, 107 developed malignancies (excluding non-melanoma skin cancer (NMSC)). The most common malignancy was lung cancer (n=24) followed by breast cancer (n=19), lymphoma (n=10) and gastric cancer (n=6). The rate of malignancies by 6-month intervals of tofacitinib exposure indicates rates remained stable over time. Standardised incidence ratios (comparison with Surveillance, Epidemiology and End Results) for all malignancies (excluding NMSC) and selected malignancies (lung, breast, lymphoma, NMSC) were within the expected range of patients with moderate-to-severe RA. Conclusions The overall rates and types of malignancies observed in the tofacitinib clinical programme remained stable over time with increasing tofacitinib exposure.

Tuberculosis and other opportunistic infections in tofacitinib-treated patients with rheumatoid arthritis

Objectives To evaluate the risk of opportunistic infections (OIs) in patients with rheumatoid arthritis (RA) treated with tofacitinib. Methods Phase II, III and long-term extension clinical trial data (April 2013 data-cut) from the tofacitinib RA programme were reviewed. OIs defined a priori included mycobacterial and fungal infections, multidermatomal herpes zoster and other viral infections associated with immunosuppression. For OIs, we calculated crude incidence rates (IRs; per 100 patient-years (95% CI)); for tuberculosis (TB) specifically, we calculated rates stratified by patient enrolment region according to background TB IR (per 100 patient-years): low (≤0.01), medium (>0.01 to ≤0.05) and high (>0.05). Results We identified 60 OIs among 5671 subjects; all occurred among tofacitinib-treated patients. TB (crude IR 0.21, 95% CI of (0.14 to 0.30)) was the most common OI (n=26); median time between drug start and diagnosis was 64 weeks (range 15–161 weeks). Twenty-one cases (81%) occurred in countries with high background TB IR, and the rate varied with regional background TB IR: low 0.02 (0.003 to 0.15), medium 0.08 (0.03 to 0.21) and high 0.75 (0.49 to 1.15). In Phase III studies, 263 patients diagnosed with latent TB infection were treated with isoniazid and tofacitinib concurrently; none developed TB. For OIs other than TB, 34 events were reported (crude IR 0.25 (95% CI 0.18 to 0.36)). Conclusions Within the global tofacitinib RA development programme, TB was the most common OI reported but was rare in regions of low and medium TB incidence. Patients who screen positive for latent TB can be treated with isoniazid during tofacitinib therapy.

Effects of tofacitinib and other DMARDs on lipid profiles in rheumatoid arthritis: implications for the rheumatologist

Cardiovascular (CV) morbidity and mortality are increased in patients with active, untreated rheumatoid arthritis (RA), despite lower levels of total and low-density lipoprotein cholesterol reported in individuals with active RA compared with those without RA. Alterations in non-traditional lipid assessments, such as high-density lipoprotein (HDL) function and HDL-associated proteins, have been described in patients with active RA, including elevated HDL-associated serum amyloid A and decreased paraoxonase-1 activity. We review changes in both traditional lipoprotein concentrations and non-traditional lipoprotein assessments in multiple studies of treatment with disease-modifying antirheumatic drugs (DMARDs), including non-biologic and biologic DMARDs and tofacitinib. In addition, data from a recently published clinical trial with tofacitinib that describe a potential mechanism for suppression of cholesterol levels in active RA patients are reviewed. Finally, CV event data from various studies of DMARDs are presented, and the current management of RA patients with regard to the CV risk is reviewed.

Lack of effect of tofacitinib (CP-690,550) on the pharmacokinetics of the CYP3A4 substrate midazolam in healthy volunteers: confirmation of in vitro data

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Tofacitinib (CP-690,550) is a novel, oral Janus kinase inhibitor being investigated as a targeted immunomodulator and disease-modifying therapy in rheumatoid arthritis. • Non-renal elimination accounts for 70% of the total clearance of tofacitinib and the metabolism is primarily mediated by cytochrome P450 (CYP) 3A4. • This study was required to determine the effect of tofacitinib on the in vivo pharmacokinetics of a sensitive CYP3A4 substrate. WHAT THIS STUDY ADDS • The pharmacokinetics of midazolam, a sensitive CYP3A4 substrate, are not altered when co-administered with tofacitinib in healthy subjects. • Tofacitinib is unlikely to affect the clearance of drugs metabolized by CYP enzymes. • There is no need for dose adjustments of CYP substrates when co-administered with tofacitinib. AIMS To investigate inhibitive and inductive effects of tofacitinib (CP-690,550), a Janus kinase inhibitor, on CYP3A4 function via in vitro and in vivo studies. METHODS In vitro experiments were conducted to assess the inhibition and induction potential of tofacitinib for major drug metabolizing enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A4). A phase 1, randomized, open-label, two-way crossover study (NCT00902460) was conducted to confirm the lack of inhibitive/inductive effect on a sensitive CYP3A4 substrate, midazolam, in healthy subjects. Midazolam pharmacokinetics were assessed over 24 h following single dose 2 mg administration prior to administering tofacitinib and after twice daily dosing of tofacitinib 30 mg for 6 days. The primary endpoint was midazolam area under the concentration-time profile, from time 0 to infinity (AUC(0,∞)). RESULTS In vitro studies demonstrated low potential for CYP inhibition (IC(50) estimates tofacitinib > 30 µm), CYP3A4 mRNA induction (observed at tofacitinib concentrations ≥ 25 µm) and no effect on enzymatic activity of CYP substrates. In the human study, AUC(0,∞) adjusted geometric mean ratio for midazolam plus tofacitinib to midazolam alone was 103.97% [90% confidence interval (CI) 95.57, 113.12], wholly within the pre-specified acceptance region (80, 125). The 90% CI for the ratio of adjusted geometric means of maximum plasma concentration (C(max) ) (95.98, 108.87) was also wholly within this acceptance region. CONCLUSIONS These data confirm a lack of an inhibitive or inductive effect of tofacitinib on CYP3A activity in humans and, in conjunction with in vitro data, support the conclusion that tofacitinib is unlikely to influence the CYP enzyme system as a whole.