Hurdles in new drug development in rheumatic diseases.

INTRODUCTION: Rheumatic diseases are heterogenous conditions with multifactorial underlying physiologic pathogeneses. Despite recent progress in the identification and development of advanced therapies primarily focusing on disrupting the immunological abnormalities that cause these conditions, rheumatic disease management remains challenging in a notable proportion of patients, with many exhibiting uncontrolled or refractory disease activity. New and improved therapies are needed to respond to this treatment gap. However, there are important hurdles that can affect the expedited identification and assessment of new treatments. METHODS: We present a review of key hurdles in the development of antirheumatic agents, as well as possible solutions to these obstacles. RESULTS: We highlight the challenges presented by incomplete understanding of the complexity of rheumatic disease pathophysiology and the resultant difficulties in the identification, development, and evaluation of new therapies. We further explore the diversity of the underlying disease processes leading to heterogeneity in patient response to treatment, necessitating the re-design of clinical trials of antirheumatic agents to detect efficacy signals and better inform clinical disease management. Finally, emergent strategies and methodologies with potential to improve upon these hurdles are presented. CONCLUSION: New and modified study designs and research tools that leverage ongoing advancements in the elucidation of rheumatic disease pathogenesis coupled with progress in methods to mine available data will be instrumental in overcoming current hurdles in antirheumatic drug development.

Infections in baricitinib clinical trials for patients with active rheumatoid arthritis.

OBJECTIVES: To evaluate the incidence of infection in patients with active rheumatoid arthritis (RA) treated with baricitinib, an oral selective Janus kinase (JAK)1 and JAK2 inhibitor. METHODS: Infections are summarised from an integrated database (8 phase 3/2/1b clinical trials and 1 long-term extension (LTE)) with data to 1 April 2017. The 'all-bari-RA' analysis set included patients who received any baricitinib dose. Placebo comparison was based on six studies with 4 mg and placebo to week 24, including four trials with 2 mg (placebo-controlled set). Dose-response assessment was based on four studies with 2 mg and 4 mg, including LTE data (2-4 mg extended set). RESULTS: There were 3492 patients who received baricitinib for 7860 patient-years (PY) of exposure (median 2.6 years, maximum 6.1 years). Treatment-emergent infections were higher for baricitinib versus placebo (exposure-adjusted incidence rate (IR)/100 PY: placebo 75.9, 2 mg 84.0 (p not significant), 4 mg 88.4 (p≤0.001)). The IR of serious infection was similar for baricitinib versus placebo and stable over time (all-bari-RA IR 3.0/100 PY). There were 11 cases of tuberculosis (all-bari-RA IR 0.1/100 PY); all occurred with 4 mg in endemic regions. Herpes zoster (HZ) IR/100 PY was higher for baricitinib versus placebo (placebo 1.0, 2 mg 3.1 (p not significant), 4 mg 4.3 (p≤0.01)); rates remained elevated and stable over time (all-bari-RA 3.3). Opportunistic infections, including multidermatomal HZ, were infrequent in the baricitinib programme (all-bari-RA IR 0.5/100 PY). CONCLUSIONS: Increased rates of treatment-emergent infections including HZ were observed in patients with RA treated with baricitinib, consistent with baricitinib's immunomodulatory mode of action.

Correction to: Temporary interruption of baricitinib: characterization of interruptions and effect on clinical outcomes in patients with rheumatoid arthritis.

An amendment to this paper has been published and can be accessed via the original article.

Temporary interruption of baricitinib: characterization of interruptions and effect on clinical outcomes in patients with rheumatoid arthritis.

BACKGROUND: In clinical practice, temporary interruption of rheumatoid arthritis (RA) therapy is common for various reasons including side effects, non-compliance, or necessity for surgery. To characterize temporary interruptions of baricitinib and placebo-matched tablets in phase 3 studies of patients with moderate-to-severe rheumatoid arthritis (RA) and describe their impact on efficacy and safety. METHODS: During 4 baricitinib phase 3 studies, investigators documented timing, reason, and duration of investigator-initiated temporary interruptions of study drug. In 2 studies, patients recorded RA symptoms in daily diaries for 12 weeks. Post hoc analyses investigated changes in symptom scores during interruptions and resumption of treatment. Interruptions were evaluated for reoccurrence of adverse events or laboratory abnormalities after retreatment. RESULTS: Across the placebo-controlled studies, interruptions occurred in larger proportions of baricitinib- (2 mg, 18%; 4 mg, 18%) vs placebo-treated (9%) patients in only one study (bDMARD-inadequate responder patients, RA-BEACON). In the active comparator-controlled studies, the lowest rates of interruption were in the baricitinib monotherapy arm (9%) of RA-BEGIN (vs methotrexate monotherapy or combination therapy), and proportions were similar for baricitinib (10%) and adalimumab (9%) in RA-BEAM. Adverse events were the most common reason for interruption, but their reoccurrence after drug restart was infrequent. Most interruptions lasted ≤ 2 weeks. Daily diaries indicated modest symptom increases during interruption with return to pre-interruption levels or better after resumption. Interruptions had no impact on long-term efficacy outcomes. CONCLUSIONS: Consistent with its pharmacologic properties, brief interruptions of baricitinib during phase 3 studies were associated with minor increases in RA symptoms that resolved following retreatment. This analysis provides useful information for clinicians, as temporary interruption of antirheumatic therapy is common in the care of patients with RA. TRIAL REGISTRATION: ClinicalTrials.gov; NCT01710358, NCT01711359, NCT01721057, NCT01721044.

Baricitinib in patients with rheumatoid arthritis with inadequate response to methotrexate: results from a phase 3 study.

OBJECTIVES: This study evaluated the efficacy and safety of baricitinib, an oral Janus kinase (JAK)1/JAK2 inhibitor, in patients with moderately to severely active rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX) therapy. METHODS: In this phase 3, double-blind, 52-week, placebo-controlled study, 290 patients with moderately to severely active RA and inadequate response to MTX were randomly assigned 1:1 to placebo or baricitinib 4-mg once daily, stratified by country (China, Brazil, Argentina) and presence of joint erosions. Primary endpoint measures included American College of Rheumatology 20% response (ACR20) at week 12. Secondary endpoints included changes in Health Assessment Questionnaire-Disability Index (HAQ-DI) and Disease Activity Score for 28-joint counts (DAS28)-high-sensitivity C-reactive protein (hsCRP), Simplified Disease Activity Index (SDAI) score ≤3.3, mean duration of morning joint stiffness, severity of morning joint stiffness numeric rating scale (NRS 0-10), worst tiredness NRS, and worst joint pain NRS at week 12. RESULTS: Most patients (approximately 80%) were from China. More patients achieved ACR20 response at week 12 with baricitinib than with placebo (58.6% vs. 28.3%; p<0.001). Statistically significant improvements were also seen in HAQ-DI, DAS28-hsCRP, morning joint stiffness, worst tiredness, and worst joint pain in the baricitinib group compared to placebo at week 12. Through week 24, rates of treatment-emergent adverse events, including infections, were higher for baricitinib compared to placebo, while serious adverse event rates were similar between baricitinib and placebo. CONCLUSIONS: In patients with RA who had an inadequate response to MTX, baricitinib was associated with significant clinical improvements as compared with placebo.

Efficacy and Safety of Long-Term Baricitinib With and Without Methotrexate for the Treatment of Rheumatoid Arthritis: Experience With Baricitinib Monotherapy Continuation or After Switching From Methotrexate Monotherapy or Baricitinib Plus Methotrexate.

OBJECTIVE: To evaluate the long-term efficacy and safety of maintaining baricitinib monotherapy in patients with active rheumatoid arthritis (RA) originally treated with baricitinib monotherapy or switched from methotrexate (MTX) or the combination of baricitinib plus MTX to baricitinib monotherapy. METHODS: This is a post hoc analysis of patients from the RA-BEGIN study who entered a long-term extension, RA-BEYOND, and were assessed for up to 24 weeks. In RA-BEGIN, MTX-naive patients with early active RA were randomized to MTX monotherapy, baricitinib 4 mg monotherapy, or baricitinib 4 mg plus MTX. At week 52, all patients entering RA-BEYOND received baricitinib 4 mg monotherapy. MTX could be prescribed during RA-BEYOND at the investigator's discretion. RESULTS: Patients in RA-BEYOND who were not rescued in RA-BEGIN (n = 423) were evaluated. Of these, 47% continued baricitinib monotherapy and 53% added MTX, with similar proportions from the 3 original arms. Patients with lower disease activity at the RA-BEYOND baseline generally continued to do well with baricitinib monotherapy as assessed by the Simplified Disease Activity Index, the Clinical Disease Activity Index, and the Health Assessment Questionnaire disability index scores. Patients prescribed MTX had higher disease activity at the RA-BEYOND baseline and had improved disease activity after the addition of MTX. Safety outcomes were similar across treatment groups. CONCLUSION: Many patients responded well to continued baricitinib monotherapy or to switching to baricitinib monotherapy from MTX monotherapy or baricitinib plus MTX, showing sustained or improved disease control. The groups of patients who had less disease control on their original therapies showed sustained or improved disease control with the addition of MTX to baricitinib.

Safety profile of baricitinib in Japanese patients with active rheumatoid arthritis with over 1.6 years median time in treatment: An integrated analysis of Phases 2 and 3 trials.

Objectives: Baricitinib is a selective oral inhibitor of JAK1/JAK2 for patients with moderately-to-severely active rheumatoid arthritis (RA). Baricitinib's safety profile in Japanese patients was evaluated using six studies (five Ph2/Ph3 trials, one long-term extension study through 01 September 2016) from an integrated database (nine RA studies).Methods: Incidence rates (IRs) or exposure-adjusted IRs (EAIRs) of adverse events (AEs) per 100 patient-years (PY) were calculated using data which included RA patients exposed to any baricitinib dose.Results: Five hundred and fourteen Japanese patients received baricitinib for 851.5 total PY of exposure (median 1.7 years, maximum 3.2). The EAIR of treatment-emergent AEs was 57.4/100PY. There were no deaths; 31 patients had serious infections (IR: 3.6/100PY), 55 herpes zoster (6.5), 0 tuberculosis, 10 malignancies (1.1) including two lymphomas, two major cardiovascular AEs (0.3), one gastrointestinal perforation (0.1), and four deep vein thrombosis (0.5). In Japanese patients, herpes zoster was more frequent than that of patients overall in the integrated database, but the events were considered manageable.Conclusion: In this analysis, baricitinib had acceptable safety profile in Japanese RA patients in the context of demonstrated efficacy. Aside from herpes zoster, baricitinib safety was not notably different between Japanese RA patients and those RA patients in the integrated database.Trial registration: NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT01721044, NCT01721057, NCT01711359, and NCT01885078 at https://clinicaltrials.gov/.

Safety profile of baricitinib for the treatment of rheumatoid arthritis over a median of 3 years of treatment: an updated integrated safety analysis.

BACKGROUND: Baricitinib is an oral selective inhibitor of Janus kinase (JAK) 1 and JAK2, approved for the treatment of patients with active rheumatoid arthritis. Because baricitinib, like other disease-modifying antirheumatic drugs, is used chronically, continuous assessment of its long-term safety profile is important. Here we provide updated data supporting the existing safety profile of baricitinib in this patient population. METHODS: In this safety analysis, integrated data were included from nine phase 3, phase 2, and phase 1b clinical trials, and one long-term extension study with data up to 360 weeks, ending Feb 13, 2018. We analysed three integrated datasets, the largest of which was the all-bari-RA dataset, which includes patients who received any dose of baricitinib. We compared the safety of baricitinib with placebo on the basis of data from seven studies with baricitinib 4 mg and placebo and four studies with baricitinib 2 mg, including placebo to week 24 (placebo-controlled dataset). We did a dose-response assessment based on four studies with baricitinib 2 mg and 4 mg, including long-term extension data (2-4 mg extended dataset). We did an exploratory analysis of deaths and venous thromboembolic events in a subset of data from the all-bari-RA dataset that included patients who had ever taken baricitinib 2-mg or baricitinib 4-mg. We did an analysis for malignancies (excluding non-melanoma skin cancer) in the as-randomised population (patients not censored at rescue or dose change). FINDINGS: We collected data for 3770 patients who were given baricitinib for 10 127 patient-years of exposure in the all-bari-RA dataset (median 1115 days [IQR 426-1441], maximum 2520 days). The placebo-controlled dataset comprised 2836 patients, with 1215 in the placebo group, with 451 patient-years of exposure data; 479 in the baricitinib 2 mg group, with 186 patient-years of exposure data; and 1142 in the baricitinib 4 mg group, with 472 patient-years of exposure data. The 2-4 mg extended dataset comprised 958 patients, with 479 in both the 2 mg and 4 mg groups. No significant differences were seen for baricitinib 4 mg or 2 mg versus placebo, or for 4 mg versus 2 mg in the incidence of death, malignancy, serious infection, or major adverse cardiovascular events. Incidence of herpes zoster per 100 patient-years was higher for baricitinib (4 mg: 4·4 [95% CI 2·7-6·7]; 2 mg: 3·1 [1·1-6·8]) versus total placebo group (1·1 [0·4-2·5]), as were treatment-emergent infections (4 mg: 89·7 [81·3-98·6]; 2 mg: 84·0 [71·3-98·2] vs placebo 75·4 [67·6-83·9]). Consistent with previous reports, incidences in the all-bari-RA dataset for venous thromboembolic events was 0·5 (95% CI 0·4-0·6) per 100 patient-years, deep-vein thrombosis was 0·3 (0·2-0·5) per 100 patient-years, and pulmonary embolism was 0·2 (0·2-0·4) per 100 patient-years. Incidences of malignancy (excluding non-melanoma skin cancer) in the 2-4 mg extended dataset were 0·8 (0·4-1·5) per 100 patient-years for baricitinib 2 mg and 1·0 (0·5-1·7) per 100 patient-years for baricitinib 4 mg, without censoring patients who had dose changes or received rescue treatment. We found no indication of higher incidence of venous thromboembolic events in the baricitinib 4 mg group compared with the 2 mg group in the 2-4 mg extended dataset. INTERPRETATION: In this updated integrated analysis of patients with active rheumatoid arthritis exposed to baricitinib for a maximum of almost 7 years, baricitinib 2 mg and 4 mg maintained a similar safety profile to earlier analyses. No new safety signals were identified. Patients in the long-term extension study continue to be followed up to date. FUNDING: Eli Lilly and Company, under license from Incyte Corporation.

Comparison of baricitinib, upadacitinib, and tofacitinib mediated regulation of cytokine signaling in human leukocyte subpopulations.

BACKGROUND: The in vitro pharmacology of baricitinib, upadacitinib, and tofacitinib was evaluated to understand differences among these JAK inhibitors (JAKis) at the cellular level. METHODS: Peripheral blood mononuclear cells from healthy donors were incubated with different JAKis, levels of phosphorylated signal transducer and activator of transcription (pSTAT) were measured following cytokine stimulation, and half maximum inhibitory concentration (IC50) values were calculated in phenotypically gated leukocyte subpopulations. Therapeutic dose relevance of the in vitro analysis was assessed using calculated mean concentration-time profiles over 24 h obtained from JAKi-treated subjects. Time above IC50 and average daily percent inhibition of pSTAT formation were calculated for each JAKi, cytokine, and cell type. RESULTS: Distinct JAKis displayed different in vitro pharmacologic profiles. For example, tofacitinib and upadacitinib were the most potent inhibitors of the JAK1/3-dependent cytokines tested (interleukin [IL]-2, IL-4, IL-15, and IL-21) with lower IC50 values and increased time above IC50 translating to a greater overall inhibition of STAT signaling during the dosing interval. All JAKis tested inhibited JAK1/2-dependent cytokines (e.g., IL-6 and interferon [IFN]-γ), the JAK1/tyrosine kinase 2 (TYK2)-dependent cytokines IL-10 and IFN-α, the JAK2/2-dependent cytokines IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF), and the JAK2/TYK2-dependent cytokine granulocyte colony-stimulating factor (G-CSF), but often to significantly differing degrees. CONCLUSIONS: Different JAKis modulated distinct cytokine pathways to varying degrees, and no agent potently or continuously inhibited an individual cytokine signaling pathway throughout the dosing interval. Notably, baricitinib inhibited JAK1/3 signaling to a lesser extent than upadacitinib and tofacitinib, while upadacitinib, baricitinib, and tofacitinib inhibited the signaling of JAK2/2-dependent cytokines, including GM-CSF and IL-3, as well as the signaling of the JAK2/TYK2-dependent cytokine G-CSF.

Clinical outcomes in patients switched from adalimumab to baricitinib due to non-response and/or study design: phase III data in patients with rheumatoid arthritis.

OBJECTIVE: To evaluate clinical outcomes in patients who changed treatment from adalimumab to baricitinib, an oral Janus kinase (JAK)1/JAK2 inhibitor, during a phase III programme. METHODS: In phase III RA-BEAM, patients were randomised 3:3:2 to placebo, baricitinib 4 mg once daily, or adalimumab 40 mg biweekly. At week 16 or subsequent visits, non-responders were rescued to open-label baricitinib 4 mg. At week 52, patients could enter a long-term extension (LTE) and continue on baricitinib or switch from adalimumab to baricitinib 4 mg with no adalimumab washout period. Percentage of patients achieving low disease activity and remission were assessed, along with physical function, patient's assessment of pain, and safety. RESULTS: Thirty-five (7%) baricitinib-treated and 40 (12%) adalimumab-treated patients were rescued to baricitinib in RA-BEAM; 78% (381/487) of baricitinib-treated and 72% (238/330) of adalimumab-treated patients who were not rescued in RA-BEAM, entered the LTE and continued/were switched to baricitinib. In both baricitinib-rescued and adalimumab-rescued patients, there were significant improvements in all measures up to 12 weeks after rescue compared with the time of rescue. Patients who switched from adalimumab to baricitinib showed improvements in disease control through 12 weeks in the LTE. Exposure-adjusted incidence rates for treatment-emergent adverse events (TEAEs) and infections, including serious events, were similar for patients who switched from adalimumab to baricitinib and those who continued on baricitinib. CONCLUSIONS: Switching from adalimumab to baricitinib (without adalimumab washout) was associated with improvements in disease control, physical function and pain during the initial 12 weeks postswitch, without an increase in TEAEs, serious adverse events or infections. TRIAL REGISTRATION NUMBERS: NCT01710358, NCT01885078.

Cardiovascular Safety During Treatment With Baricitinib in Rheumatoid Arthritis.

OBJECTIVE: To assess the frequency of cardiovascular and venous thromboembolic events in clinical studies of baricitinib, an oral, selective JAK1 and JAK2 inhibitor approved in more than 50 countries for the treatment of moderately-to-severely active rheumatoid arthritis (RA). METHODS: Data were pooled from 9 RA studies. Placebo comparison up to 24 weeks included data from 6 studies. Randomized dose comparison between baricitinib doses of 2 mg and 4 mg used data from 4 studies and from the associated long-term extension study. The data analysis set designated "All-bari-RA" included all baricitinib exposures at any dose. RESULTS: Overall, 3,492 RA patients received baricitinib (7,860 patient-years of exposure). No imbalance compared to the placebo group was seen in the incidence of major adverse cardiovascular events (MACE) (incidence rates [IRs] of 0.5 per 100 patient-years for placebo and 0.8 per 100 patient-years for 4 mg baricitinib), arterial thrombotic events (ATE) (IRs of 0.5 per 100 patient-years for placebo and 0.5 per 100 patient-years for 4 mg baricitinib), or congestive heart failure (CHF) broad term (IRs of 4.3 per 100 patient-years for placebo and 2.4 per 100 patient-years for 4 mg baricitinib). Deep vein thrombosis (DVT)/pulmonary embolism (PE) were reported in 0 of 1,070 patients treated with placebo and 6 of 997 patients treated with 4 mg baricitinib during the placebo-controlled period; these events were serious in 2 of 6 patients, while all 6 had risk factors and 1 patient developed DVT/PE after discontinuation of the study drug. In the 2 mg-4 mg-extended data analysis set, IRs of DVT/PE were comparable between the doses across event types (IRs of 0.5 per 100 patient-years in those receiving 2 mg baricitinib and 0.6 per 100 patient-years in those receiving 4 mg baricitinib). In the All-bari-RA data analysis set, the rates were stable over time, with an IR of DVT/PE of 0.5 per 100 patient-years. CONCLUSION: In RA clinical trials, no association was found between baricitinib treatment and the incidence of MACE, ATE, or CHF. With regard to incidence of DVT/PE, 6 events occurred in patients treated with 4 mg baricitinib, but no cases of DVT/PE were reported in the placebo group. During longer-term evaluation, the incidence of DVT/PE was similar between the baricitinib dose groups, with consistent IR values over time, and this was similar to the rates previously reported in patients with RA.

Safety Profile of Baricitinib in Patients with Active Rheumatoid Arthritis with over 2 Years Median Time in Treatment.

OBJECTIVE: Baricitinib is an oral, once-daily selective Janus kinase (JAK1/JAK2) inhibitor for adults with moderately to severely active rheumatoid arthritis (RA). We evaluated baricitinib's safety profile through 288 weeks (up to September 1, 2016) with an integrated database [8 phase III/II/Ib trials, 1 longterm extension (LTE)]. METHODS: The "all-bari-RA" group included patients who received any baricitinib dose. Placebo comparison was based on the 6 studies with 4 mg and placebo up to Week 24 ("placebo-4 mg" dataset). Dose response assessment was based on 4 studies with 2 mg and 4 mg including LTE data ("2 mg-4 mg-extended"). The uncommon events description used the non-controlled all-bari-RA. RESULTS: There were 3492 patients who received baricitinib for 6637 total patient-years (PY) of exposure (median 2.1 yrs, maximum 5.5 yrs). No differences in rates of death, adverse events leading to drug discontinuation, malignancies, major adverse cardiovascular event (MACE), or serious infections were seen for 4 mg versus placebo or for 4 mg versus 2 mg. Infections including herpes zoster were significantly more frequent for 4 mg versus placebo. Deep vein thrombosis/pulmonary embolism were reported with 4 mg but not placebo [all-bari-RA incidence rate (IR) 0.5/100 PY]; the IR did not differ between doses (0.5 vs 0.6/100 PY, 2 mg vs 4 mg, respectively) or compared to published RA rates. All-bari-RA had 6 cases of lymphoma (IR 0.09/100 PY), 3 gastrointestinal perforations (0.05/100 PY), 10 cases of tuberculosis (all in endemic areas; 0.15/100 PY), and 22 all-cause deaths (0.33/100 PY). IR for malignancies (0.8/100 PY) and MACE (0.5/100 PY) were low and did not increase with prolonged exposure. CONCLUSION: In this integrated analysis of patients with moderate to severe active RA with exposure up to 5.5 years, baricitinib has an acceptable safety profile in the context of demonstrated efficacy. Trial registration numbers: NCT01185353, NCT00902486, NCT01469013, NCT01710358, NCT01721044, NCT01721057, NCT01711359, and NCT01885078 at clinicaltrials.gov.

Dose reduction of baricitinib in patients with rheumatoid arthritis achieving sustained disease control: results of a prospective study.

OBJECTIVES: This study investigated the effects of dose step-down in patients with rheumatoid arthritis (RA) who achieved sustained disease control with baricitinib 4 mg once a day. METHODS: Patients who completed a baricitinib phase 3 study could enter a long-term extension (LTE). In the LTE, patients who received baricitinib 4 mg for ≥15 months and maintained CDAI low disease activity (LDA) or remission (REM) were blindly randomised to continue 4 mg or taper to 2 mg. Patients could rescue (to 4 mg) if needed. Efficacy and safety were assessed through 48 weeks. RESULTS: Patients in both groups maintained LDA (80% 4 mg; 67% 2 mg) or REM (40% 4 mg; 33% 2 mg) over 48 weeks. However, dose reduction resulted in small, statistically significant increases in disease activity at 12, 24 and 48 weeks. Dose reduction also produced earlier and more frequent relapse (loss of step-down criteria) over 48 weeks compared with 4 mg maintenance (23% 4 mg vs 37% 2 mg, p=0.001). Rescue rates were 10% for baricitinib 4 mg and 18% for baricitinib 2 mg. Dose reduction was associated with a numerically lower rate of non-serious infections (30.6 for baricitinib 4 mg vs 24.9 for 2 mg). Rates of serious adverse events and adverse events leading to discontinuation were similar across groups. CONCLUSIONS: In a large randomised, blinded phase 3 study, maintenance of RA control following induction of sustained LDA/REM with baricitinib 4 mg was greater with continued 4 mg than after taper to 2 mg. Nonetheless, most patients tapered to 2 mg could maintain LDA/REM or recapture with return to 4 mg if needed.

Characterization and Changes of Lymphocyte Subsets in Baricitinib-Treated Patients With Rheumatoid Arthritis: An Integrated Analysis.

OBJECTIVE: Baricitinib is an orally administered inhibitor of JAK1 and JAK2 that has been shown to be effective in treating rheumatoid arthritis (RA). This study was undertaken to analyze changes in lymphocyte cell subsets during baricitinib treatment and to correlate these changes with clinical outcomes. METHODS: An integrated analysis was conducted by pooling data from 3 completed phase III trials comparing placebo with baricitinib treatment (RA-BEAM, RA-BUILD, and RA-BEACON) and 1 ongoing long-term extension study (RA-BEYOND) in patients with active RA (n = 2,186). RESULTS: Baricitinib treatment was associated with an early transient increase in total lymphocyte count at week 4, which returned to baseline by week 12. Transient changes within normal reference ranges in T cells and subsets were observed with baricitinib treatment, up to week 104. B cells and relevant subpopulations increased after 4 weeks of baricitinib treatment, with no further increases noted through 104 weeks of treatment. Natural killer (NK) cells temporarily increased after 4 weeks of baricitinib treatment, before decreasing below baseline levels and then stabilizing over time. With baricitinib treatment, few correlations were observed between changes in lymphocyte subsets and clinical end points, and most correlations were also observed within the placebo group. A modest potential association between low NK cell numbers and treatment-emergent infections was observed in the baricitinib 4 mg/day treatment group, but not for serious infections or herpes zoster. CONCLUSION: Overall, these findings demonstrate that changes in lymphocyte subsets were largely within normal reference ranges across the baricitinib phase III RA clinical program and were not associated with increased risk of serious infections.

Effects of baricitinib on radiographic progression of structural joint damage at 1 year in patients with rheumatoid arthritis and an inadequate response to conventional synthetic disease-modifying antirheumatic drugs.

BACKGROUND: Baricitinib was efficacious in a 24-week phase III study in patients with rheumatoid arthritis (RA) and an inadequate response to conventional synthetic disease-modifying anti rheumatic drugs (DMARDs) (csDMARDs) (RA-BUILD). OBJECTIVES: To evaluate radiographic progression of structural joint damage in RA-BUILD patients over 48 weeks of baricitinib treatment in the long-term extension study, RA-BEYOND. METHODS: In RA-BUILD, patients were randomised to placebo, baricitinib 2 mg or 4 mg once daily, with rescue possible from week 16. Patients completing RA-BUILD and entering RA-BEYOND continued to receive the baricitinib dose received at the end of RA-BUILD. Patients receiving placebo were switched to baricitinib 4 mg in RA-BEYOND. Joint damage was measured using the van der Heijde modified total Sharp score. To account for missing scores and scores obtained after rescue, switch or discontinuation of study drug, data were analysed using (1) linear extrapolation (LE) and (2) observed/last observation carried forward (LOCF). The observed/LOCF method used all available observed data, including after rescue or switch, with patients analysed according to original treatment assignment. RESULTS: Using LE, radiographic progression at 24 and 48 weeks was statistically significantly lower for both baricitinib 2 or 4 mg compared with placebo. Only baricitinib 4 mg demonstrated statistically significant inhibition of progressive radiographic joint damage compared with patients initially randomised to placebo using observed/LOCF at week 48. CONCLUSIONS: Once daily oral baricitinib inhibited radiographic progression of structural joint damage in patients with an inadequate response or intolerance to csDMARDs over 48 weeks. The most robust benefit was seen for the 4 mg dose.

Lipid profile and effect of statin treatment in pooled phase II and phase III baricitinib studies.

OBJECTIVES: Lipid profiles are altered by active disease in patients with rheumatoid arthritis (RA) and may be further modified by treatment with Janus kinase inhibitors and other disease-modifying antirheumatic drugs. METHODS: Lipid data were analysed from phase II and III studies of 4 mg (n=997) and 2 mg (n=479) oral baricitinib administered once daily in patients with moderate-to-severe active RA. Lipoprotein particle size and number and GlycA were evaluated with nuclear magnetic resonance in one phase III study. The effect of statin therapy on lipid levels was evaluated in patients on statins at baseline and in patients who initiated statins during the study. RESULTS: Treatment with baricitinib was associated with increased levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides, but no significant change in LDL-C:HDL-C ratio. Lipid levels plateaued after 12 weeks of treatment. Baricitinib treatment increased large LDL and decreased small, dense LDL particle numbers and GlycA. Lipid changes from baseline were not significantly different between baseline statin users and non-users. In patients who initiated statin therapy during the study, LDL-C, triglycerides (baricitinib 4 mg only) and apolipoprotein B decreased to pre-baricitinib levels; HDL-C and apolipoprotein A-I levels remained elevated. CONCLUSIONS: Baricitinib was associated with increased LDL-C, HDL-C and triglyceride levels, but did not alter the LDL-C:HDL-C ratio. Evaluation of cardiovascular event rates during long-term treatment is warranted to further characterise these findings and their possible clinical implications. TRIAL REGISTRATION NUMBER: NCT00902486, NCT01469013, NCT01185353, NCT01721044, NCT01721057, NCT01711359, NCT01710358, NCT01885078.

Response to baricitinib based on prior biologic use in patients with refractory rheumatoid arthritis.

Objective: RA patients who have failed biologic DMARDs (bDMARDs) represent an unmet medical need. We evaluated the effects of baseline characteristics, including prior bDMARD exposure, on baricitinib efficacy and safety. Methods: RA-BEACON patients (previously reported) had moderate to severe RA with insufficient response to one or more TNF inhibitor and were randomized 1:1:1 to once-daily placebo or 2 or 4 mg baricitinib. Prior bDMARD use was allowed. The primary endpoint was a 20% improvement in ACR criteria (ACR20) at week 12 for 4 mg vs placebo. An exploratory, primarily post hoc, subgroup analysis evaluated efficacy at weeks 12 and 24 by ACR20 and Clinical Disease Activity Index (CDAI) ⩽10. An interaction P-value ⩽0.10 was considered significant, with significance at both weeks 12 and 24 given more weight. Results: The odds ratios predominantly favored baricitinib over placebo and were generally similar to those in the overall study (3.4, 2.4 for ACR20 weeks 12 and 24, respectively). Significant quantitative interactions were observed for baricitinib 4 mg vs placebo at weeks 12 and 24: ACR20 by region (larger effect Europe) and CDAI ⩽10 by disease duration (larger effect ⩾10 years). No significant interactions were consistently observed for ACR20 by age; weight; disease duration; seropositivity; corticosteroid use; number of prior bDMARDs, TNF inhibitors or non-TNF inhibitors; or a specific prior TNF inhibitor. Treatment-emergent adverse event rates, including infections, appeared somewhat higher across groups with greater prior bDMARD use. Conclusion: Baricitinib demonstrated a consistent, beneficial treatment effect in bDMARD-refractory patients across subgroups based on baseline characteristics and prior bDMARD use. Trial registration: ClinicalTrials.gov (https://clinicaltrials.gov/), NCT01721044.

Efficacy and safety of baricitinib in Japanese patients with active rheumatoid arthritis: A 52-week, randomized, single-blind, extension study.

OBJECTIVES: The objective of this study is to evaluate the efficacy and safety of long-term (64 weeks; 52-week extension of a 12-week study) baricitinib treatment in Japanese patients with active rheumatoid arthritis (RA) despite methotrexate therapy. METHODS: Patients (N = 145) with active RA were randomized to placebo, 1mg, 2mg, 4mg, or 8mg baricitinib for the first 12 weeks. During the 52-week extension period, patients on 4mg or 8mg baricitinib remained on the same dose and all other patients were re-randomized to 4mg or 8mg baricitinib. Most patients on 8mg baricitinib were switched to 4mg by week 64 (protocol amendment); data analysis was based on the treatment group at the beginning of the extension period. RESULTS: Increases in the American College of Rheumatology (ACR) response rates (ACR20, ACR50, and ACR70) observed during the first 12 weeks were maintained during the extension period, accompanied by improvements in ACR core components. At week 64, a large proportion of patients (>40%) had low disease activity. Most treatment-related adverse events were mild or moderate; herpes zoster was the most common reason (11/27 patients) for discontinuation. CONCLUSIONS: The efficacy and safety profile of baricitinib was maintained during long-term treatment of Japanese patients with RA and background methotrexate therapy. Clinicaltrials.gov NCT01469013; Funding: Eli Lilly and Incyte.

Safety and Efficacy of Baricitinib Through 128 Weeks in an Open-label, Longterm Extension Study in Patients with Rheumatoid Arthritis.

OBJECTIVE: To assess the safety and efficacy of baricitinib in patients with rheumatoid arthritis (RA) up to 128 weeks in a phase IIb study (NCT01185353). METHODS: After a 24-week blinded period, eligible patients entered an initial 52-week open-label extension (OLE); patients receiving 8 mg once daily (QD) continued with that dose and all others received 4 mg QD. Doses could be escalated to 8 mg QD at 28 or 32 weeks at investigator discretion when ≥ 6 tender and ≥ 6 swollen joints were present. Patients completing the first OLE were eligible to enter a second 52-week OLE and receive 4 mg QD regardless of previous dose. RESULTS: In the 4-mg (n = 108) and 8-mg (n = 93) groups, treatment-emergent adverse events (AE) occurred in 63% and 67%, serious AE in 16% and 13%, infections in 35% and 40%, and serious infections in 5% and 3% of patients, respectively. Exposure-adjusted incidence rates for AE for all baricitinib groups in the second OLE were similar to or lower than rates observed in the first OLE. No opportunistic infections, tuberculosis cases, or lymphomas were observed through 128 weeks; 1 death occurred during the first OLE. Among all patients in both OLE, the proportions who achieved disease improvement at Week 24 were similar or increased at weeks 76 and 128. CONCLUSION: In a phase IIb study in RA, the safety and tolerability profile of baricitinib, up to 128 weeks, remained consistent with earlier observations, without unexpected late signals. Clinical improvements seen in the 24-week blinded period were maintained during the OLE.

Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials.

OBJECTIVES: To evaluate efficacy/safety of baricitinib for rheumatoid arthritis (RA) in Japanese subpopulations from four phase 3 studies, and assess whether results in these subpopulations are consistent with the overall study populations. METHODS: Subgroup analyses (394 patients) of four phase 3 randomized controlled trials: RA-BEGIN [no or limited treatment with disease-modifying antirheumatic drugs (DMARDs)], RA-BEAM [inadequate response (IR) to methotrexate], RA-BUILD [IR to conventional synthetic DMARDs (csDMARDs)], and RA-BEACON (IR to tumor necrosis factor inhibitors receiving csDMARDs). RESULTS: For American College of Rheumatology 20% improvement (ACR20) response rate, Japanese patients receiving baricitinib 4-mg showed similar improvement compared to methotrexate at Week 24 (72 versus 69%; RA-BEGIN), and greater improvement compared with placebo at Week 12 (67 versus 34%; RA-BEAM). Japanese patients receiving baricitinib 4-mg also showed greater improvement compared with placebo at Week 12 in RA-BUILD and RA-BEACON. Across all studies, baricitinib was well-tolerated, with no deaths and one malignancy. In RA-BEGIN and RA-BEAM, herpes zoster rates were higher for Japanese patients than for overall populations; all events were mild/moderate. CONCLUSION: Data for baricitinib, with/without methotrexate, in Japanese subpopulations across all stages of the RA treatment continuum accord with the efficacy/safety profile in overall study populations. Baricitinib appears to be similarly effective in Japanese patients.