Integrated safety analysis of filgotinib treatment for rheumatoid arthritis in patients from Japan over a median of 1.5 years.

OBJECTIVE: Characterize safety of the Janus kinase-1 preferential inhibitor filgotinib (FIL) in Japanese patients with moderately to severely active rheumatoid arthritis (RA). METHODS: Data from three Phase 3 trials (NCT02889796, NCT02873936, and NCT02886728) and a long-term extension (NCT03025308) through September 2019 were integrated; patients received ≥1 dose of FIL 200 (FIL200) or 100 mg (FIL100) daily, or placebo (PBO). We calculated exposure-adjusted incidence rates (EAIRs) per 100 patient-years FIL exposure (100PYE) for treatment-emergent adverse events (TEAEs) and adverse events of special interest. RESULTS: Among 3691 total patients and 6080.7 PYE, 229 Japanese patients received FIL for 311.4 PYE (median 1.5, maximum 2.5 years). During the 12-week PBO-controlled period, serious TEAEs and TEAEs leading to study drug disruption were comparable between FIL and PBO. Serious infection rates were 1.9%, 0%, and 2% for FIL200, FIL100, and PBO during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.8 and 2.1/100PYE. No herpes zoster (HZ) or major adverse cardiovascular events (MACEs) occurred during the PBO-controlled period; long-term FIL200 and FIL100 EAIRs were 3.0 and 2.1/100PYE (HZ) and 0.6 and 0/100PYE (MACE). CONCLUSION: Long-term FIL treatment (median 1.5, maximum 2.5 years exposure) was well tolerated at 100- and 200-mg doses in Japanese patients with RA.

Safety and efficacy of filgotinib for Japanese patients with RA and inadequate response to MTX: FINCH 1 52-week results and FINCH 4 48-week results.

OBJECTIVES: To present safety and efficacy of the JAK1 preferential inhibitor filgotinib in Japanese patients with prior inadequate response (IR) to methotrexate (MTX) from a 52-week randomised controlled parent study (PS) and long-term extension (LTE) through June 2020. METHODS: The PS (NCT02889796) randomised MTX-IR patients to filgotinib 200 (FIL200) or 100 mg (FIL100), adalimumab (ADA) 40 mg, or placebo; all took stable background MTX. At week (W) 24, placebo patients were rerandomised to FIL200 or FIL100. The primary endpoint was W12 American College of Rheumatology 20% improvement; safety was assessed by adverse event (AE) reporting. For the LTE (NCT03025308), eligible filgotinib patients continued FIL200/FIL100; ADA patients were rerandomised (blinded) to FIL200 or FIL100; all continued MTX. RESULTS: In all, 114/147 Japanese patients completed the PS, 115 enrolled in LTE, and 103 remained on study in June 2020. In the PS, AEs were consistent with the overall population, and W24 efficacy was maintained or improved through W52, comparable with the overall population. LTE AE incidences were similar between doses; filgotinib efficacy was consistent from baseline to W48 and similar between PS ADA and filgotinib patients. CONCLUSIONS: Among MTX-IR Japanese patients, filgotinib maintained efficacy over 1 year; LTE safety was consistent with the PS.

Long-term safety and efficacy of filgotinib treatment for rheumatoid arthritis in Japanese patients naïve to MTX treatment (FINCH 3).

OBJECTIVES: To evaluate the long-term safety and efficacy of filgotinib (FIL) for Japanese patients with rheumatoid arthritis (RA) and limited/no prior methotrexate (MTX) exposure. We present a Japanese population subanalysis of a global randomised-controlled trial at Week 52 and interim long-term extension (LTE) to Week 48 through June 2020. METHODS: Patients were randomised to FIL 200 mg plus MTX, FIL 100 mg plus MTX, FIL 200 mg, or MTX for 52 weeks. At completion, eligible patients could enrol in the LTE. Those receiving FIL continued; those receiving MTX were rerandomised (blinded) to FIL 200 or 100 mg upon discontinuation of MTX. After a 4-week washout period, MTX could be re-added. RESULTS: Adverse event rates at Week 52 and in the LTE to Week 48 were comparable across treatment groups. Week 52 American College of Rheumatology 20% improvement (ACR20) rates were 83% (19/23), 82% (9/11), 75% (9/12), and 76% (19/25) for FIL 200 mg plus MTX, FIL 100 mg plus MTX, FIL 200 mg, and MTX, respectively. Through LTE Week 48, ACR20 rates were maintained. CONCLUSIONS: In the 56 Japanese patients treated with FIL, efficacy was maintained through Week 52 and beyond, with no increases in the incidence of adverse events.

Integrated safety analysis of filgotinib in patients with moderately to severely active rheumatoid arthritis receiving treatment over a median of 1.6 years.

OBJECTIVE: To characterise safety of the Janus kinase-1 preferential inhibitor filgotinib in patients with moderately to severely active rheumatoid arthritis. METHODS: Data were integrated from seven trials (NCT01668641, NCT01894516, NCT02889796, NCT02873936, NCT02886728, NCT02065700, NCT03025308). Results are from placebo (PBO)-controlled (through week (W)12) and long-term, as-treated (all available data for patients receiving ≥1 dose filgotinib 200 (FIL200) or 100 mg (FIL100) daily) datasets. We calculated exposure-adjusted incidence rates (EAIRs)/100 patient-years filgotinib exposure (100PYE) for treatment-emergent adverse events (TEAEs). RESULTS: 3691 patients received filgotinib for 6080.7 PYE (median 1.6, maximum 5.6 years). During the PBO-controlled period, TEAEs, including those of grade ≥3, occurred at comparable rates with filgotinib or PBO; long-term EAIRs of TEAEs grade ≥3 were 6.4 and 7.6/100PYE for FIL200 and FIL100. EAIRs for deaths were 0.6/100PYE for FIL200, FIL100 and PBO; long-term EAIRs were 0.5 and 0.3/100PYE for FIL200 and FIL100. EAIRs for serious infection were 3.9, 3.3 and 2.4/100PYE for FIL200, FIL100 and PBO; long-term EAIRs were 1.6 and 3.1/100PYE for FIL200 and FIL100. EAIRs for herpes zoster were 0.6, 1.1, and 1.1/100PYE for FIL200, FIL100 and PBO; long-term EAIRs were 1.8 and 1.1/100PYE for FIL200 and FIL100. EAIRs for major adverse cardiovascular events were 0, 1.7 and 1.1/100PYE for FIL200, FIL100 and PBO; long-term EAIRs were 0.4 and 0.6/100PYE for FIL200 and FIL100. No venous thromboembolism occurred during the PBO-controlled period; long-term EAIRs were 0.2 and 0/100PYE for FIL200 and FIL100. CONCLUSIONS: Over a median of 1.6 and maximum of 5.6 years of exposure, safety/tolerability of FIL200 and FIL100 were similar, with a lower incidence of infections with FIL200 among the long-term, as-treated dataset.

Exposure-response relationships for the efficacy and safety of filgotinib and its metabolite GS-829845 in subjects with rheumatoid arthritis based on phase 2 and phase 3 studies.

AIMS: Filgotinib is a potent, oral, JAK1-preferential inhibitor for the treatment of rheumatoid arthritis (RA). This report describes exposure-response (ER) analyses of filgotinib for dose confirmation based on three phase 3 and two phase 2 studies in moderate to severe RA patients. METHODS: The pharmacokinetic exposures used in ER analyses were derived from population pharmacokinetic analysis. The exposure-efficacy relationships were assessed for efficacy endpoints (ACR20/50/70 and DAS28) over effective area under curve (AUCeff ), the combined exposures of filgotinib and GS-829845 (major, active metabolite), with nonlinear logistic regression models developed. Also, a t-test was performed to compare the exposure between subjects who achieved response and those who did not. For the ER analyses of safety, exposures were examined between subjects who experienced and who did not experience the evaluated safety events, which was conducted separately for filgotinib and GS-829845. RESULTS: The nonlinear logistic regression showed increasing response with increasing exposure, with exposures at 200 mg dose primarily residing on the curve plateau. Also, AUCeff was significantly higher in the subjects who achieved responses compared to those who did not (10 900 vs 9900 h*ng/mL for ACR20, P value < .0001). For exposure-safety analyses, filgotinib and GS-829845 exposures were similar irrespective of the presence/absence of the evaluated safety endpoints, indicating no exposure-safety relationship for common treatment-emergent adverse events (TEAEs)/laboratory abnormalities and serious TEAEs/infections. CONCLUSIONS: ER analyses confirmed that filgotinib produced more robust therapeutic effects across the exposure range observed at 200 mg once daily compared to lower doses, and collectively with the lack of exposure-safety relationship, the 200 mg once daily dose was supported for commercialization.

Efficacy and safety of filgotinib in Japanese patients with refractory rheumatoid arthritis: Subgroup analyses of a global phase 3 study (FINCH 2).

OBJECTIVES: To evaluate efficacy and safety of filgotinib in Japanese RA patients who have failed or were intolerant to one or more biologic disease-modifying antirheumatic drugs (bDMARD) from the global FINCH 2 study (NCT02873936). METHODS: This subgroup analysis was performed using the predefined statistical analyses. The FINCH 2 study is a randomized, double-blind, placebo-controlled, Phase 3 study in adult RA patients with inadequate response to bDMARDs. The randomized patients were treated with once-daily filgotinib 200 mg, filgotinib 100 mg or placebo on a background of csDMARDs for 24 weeks. RESULTS: Of 449 patients enrolled in the overall population, 40 patients were enrolled from Japan. In the Japanese population, the American College of Rheumatology 20% response rates at week 12 (primary endpoint) were 83.3% and 53.3% for filgotinib, 200 mg and 100 mg, respectively, vs 30.8% for placebo. Filgotinib was well tolerated, similar to the overall population. CONCLUSIONS: Both doses of once-daily filgotinib 200 mg and filgotinib 100 mg were effective, and generally well-tolerated in Japanese patients with active refractory RA.

Efficacy and safety of filgotinib in combination with methotrexate in Japanese patients with active rheumatoid arthritis who have an inadequate response to methotrexate: Subpopulation analyses of 24-week data of a global phase 3 study (FINCH 1).

OBJECTIVES: Evaluate the efficacy and safety of the Janus kinase-1 inhibitor filgotinib in Japanese patients with rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX). METHODS: Data from 147 Japanese patients in FINCH 1, a 52-week global Phase 3 study, were analysed up to 24 weeks. Patients received once-daily filgotinib 200 or 100 mg, biweekly adalimumab, or placebo, all with stable background MTX. RESULTS: In the Japanese population, American College of Rheumatology 20% response rates at Week 12 (primary endpoint) were 77.5%, 65.9%, 53.6%, and 36.8% for filgotinib 200 mg, filgotinib 100 mg, adalimumab, and placebo. Proportions of patients achieving Disease Activity Score with 28 joints <2.6 at Week 24: filgotinib 200 mg, 65.0%; filgotinib 100 mg, 51.2%; adalimumab, 42.9%; and placebo, 5.3%. Incidence rates of serious infections: filgotinib 200 mg, 2.5%; filgotinib 100 mg, 0%; adalimumab, 10.7%; and placebo, 5.3%. Treatment-emergent laboratory abnormalities Grade ≥3 occurred in five (12.5%) filgotinib 200 mg, three (7.3%) filgotinib 100 mg, one (3.6%) adalimumab, and no placebo patients. No deaths were reported among Japanese patients. CONCLUSIONS: Filgotinib once daily combined with MTX was effective and generally safe and well tolerated up to Week 24 in Japanese patients with RA and inadequate response to MTX.

Efficacy and safety of filgotinib alone and in combination with methotrexate in Japanese patients with active rheumatoid arthritis and limited or no prior exposure to methotrexate: Subpopulation analyses of 24-week data of a global phase 3 study (FINCH 3).

OBJECTIVES: To evaluate the efficacy and safety of filgotinib for Japanese patients with rheumatoid arthritis (RA) and limited or no prior methotrexate (MTX) exposure. METHODS: Data up to 24 weeks were analysed for 71 Japanese patients from a 52-week global Phase 3 study. Patients with RA and limited or no prior MTX exposure were randomised in a 2:1:1:2 ratio to filgotinib 200 mg plus MTX, filgotinib 100 mg plus MTX, filgotinib 200 mg, or MTX. Maximum MTX dose was 15 mg/week. Primary endpoint was proportion achieving 20% improvement in American College of Rheumatology criteria (ACR20) at Week 24. RESULTS: Week 24 ACR20 rates in Japanese patients were 82.6%, 90.9%, 83.3%, and 80.0% for filgotinib 200 mg plus MTX, filgotinib 100 mg plus MTX, filgotinib 200 mg, and MTX, respectively. Greater ACR20 rates with filgotinib vs MTX occurred at Week 2. Greater proportions receiving filgotinib vs MTX achieved DAS28-CRP <2.6 at Weeks 12 and 24. Adverse event rates were comparable across treatments and between the Japanese and overall populations. CONCLUSIONS: While Week 24 ACR20 rates were similar, filgotinib provided faster responses and higher remission rates vs MTX. In Japanese patients with RA and limited or no prior MTX exposure, filgotinib was generally well tolerated.

Filgotinib versus placebo or adalimumab in patients with rheumatoid arthritis and inadequate response to methotrexate: a phase III randomised clinical trial.

OBJECTIVE: To evaluate the efficacy and safety of the Janus kinase-1-preferential inhibitor filgotinib versus placebo or tumour necrosis factor-α inhibitor therapy in patients with active rheumatoid arthritis (RA) despite ongoing treatment with methotrexate (MTX). METHODS: This 52-week, multicentre, double-blind, placebo-controlled and active-controlled phase III trial evaluated once-daily oral filgotinib in patients with RA randomised 3:3:2:3 to filgotinib 200 mg (FIL200) or filgotinib 100 mg (FIL100), subcutaneous adalimumab 40 mg biweekly, or placebo (through week 24), all with stable weekly background MTX. The primary endpoint was the proportion of patients achieving 20% improvement in American College of Rheumatology criteria (ACR20) at week 12. Additional efficacy outcomes were assessed sequentially. Safety was assessed from adverse events and laboratory abnormalities. RESULTS: The proportion of patients (n=1755 randomised and treated) achieving ACR20 at week 12 was significantly higher for FIL200 (76.6%) and FIL100 (69.8%) versus placebo (49.9%; treatment difference (95% CI), 26.7% (20.6% to 32.8%) and 19.9% (13.6% to 26.2%), respectively; both p<0.001). Filgotinib was superior to placebo in key secondary endpoints assessing RA signs and symptoms, physical function and structural damage. FIL200 was non-inferior to adalimumab in terms of Disease Activity Score in 28 joints with C reactive protein ≤3.2 at week 12 (p<0.001); FIL100 did not achieve non-inferiority. Adverse events and laboratory abnormalities were comparable among active treatment arms. CONCLUSIONS: Filgotinib improved RA signs and symptoms, improved physical function, inhibited radiographic progression and was well tolerated in patients with RA with inadequate response to MTX. FIL200 was non-inferior to adalimumab. TRIAL REGISTRATION NUMBER: NCT02889796.

Filgotinib in combination with methotrexate or as monotherapy versus methotrexate monotherapy in patients with active rheumatoid arthritis and limited or no prior exposure to methotrexate: the phase 3, randomised controlled FINCH 3 trial.

OBJECTIVES: To investigate efficacy and safety of the Janus kinase-1 inhibitor filgotinib in patients with active rheumatoid arthritis (RA) with limited or no prior methotrexate (MTX) exposure. METHODS: This 52-week, phase 3, multicentre, double-blind clinical trial (NCT02886728) evaluated once-daily oral filgotinib in 1252 patients with RA randomised 2:1:1:2 to filgotinib 200 mg with MTX (FIL200 +MTX), filgotinib 100 mg with MTX (FIL100 +MTX), filgotinib 200 mg monotherapy (FIL200), or MTX. The primary endpoint was proportion achieving 20% improvement in American College of Rheumatology criteria (ACR20) at week 24. RESULTS: The primary endpoint was achieved by 81% of patients receiving FIL200+ MTX versus 71% receiving MTX (p<0.001). A significantly greater proportion treated with FIL100+ MTX compared with MTX achieved an ACR20 response (80%, p=0.017) at week 24. Significant improvement in Health Assessment Questionnaire-Disability Index was seen at week 24; least-squares mean change from baseline was -1.0 and -0.94 with FIL200+MTX and FIL100+MTX, respectively, versus -0.81 with MTX (p<0.001, p=0.008, respectively). Significantly higher proportions receiving FIL200+MTX (54%) and FIL100+MTX (43%) achieved DAS28(CRP) <2.6 versus MTX (29%) (p<0.001 for both) at week 24. Hierarchical testing stopped for comparison of ACR20 for FIL200 monotherapy (78%) versus MTX (71%) at week 24 (p=0.058). Adverse event rates through week 52 were comparable between all treatments. CONCLUSIONS: FIL200+MTX and FIL100+MTX both significantly improved signs and symptoms and physical function in patients with active RA and limited or no prior MTX exposure; FIL200 monotherapy did not have a superior ACR20 response rate versus MTX. Filgotinib was well tolerated, with acceptable safety compared with MTX.

PTPN14 phosphatase and YAP promote TGFß signalling in rheumatoid synoviocytes.

OBJECTIVE: We aimed to understand the role of the tyrosine phosphatase PTPN14-which in cancer cells modulates the Hippo pathway by retaining YAP in the cytosol-in fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). METHODS: Gene/protein expression levels were measured by quantitative PCR and/or Western blotting. Gene knockdown in RA FLS was achieved using antisense oligonucleotides. The interaction between PTPN14 and YAP was assessed by immunoprecipitation. The cellular localisation of YAP and SMAD3 was examined via immunofluorescence. SMAD reporter studies were carried out in HEK293T cells. The RA FLS/cartilage coimplantation and passive K/BxN models were used to examine the role of YAP in arthritis. RESULTS: RA FLS displayed overexpression of PTPN14 when compared with FLS from patients with osteoarthritis (OA). PTPN14 knockdown in RA FLS impaired TGFß-dependent expression of MMP13 and potentiation of TNF signalling. In RA FLS, PTPN14 formed a complex with YAP. Expression of PTPN14 or nuclear YAP-but not of a non-YAP-interacting PTPN14 mutant-enhanced SMAD reporter activity. YAP promoted TGFß-dependent SMAD3 nuclear localisation in RA FLS. Differences in epigenetic marks within Hippo pathway genes, including YAP, were found between RA FLS and OA FLS. Inhibition of YAP reduced RA FLS pathogenic behaviour and ameliorated arthritis severity. CONCLUSION: In RA FLS, PTPN14 and YAP promote nuclear localisation of SMAD3. YAP enhances a range of RA FLS pathogenic behaviours which, together with epigenetic evidence, points to the Hippo pathway as an important regulator of RA FLS behaviour.

Effect of Filgotinib vs Placebo on Clinical Response in Patients With Moderate to Severe Rheumatoid Arthritis Refractory to Disease-Modifying Antirheumatic Drug Therapy: The FINCH 2 Randomized Clinical Trial.

Importance: Patients with active rheumatoid arthritis (RA) despite treatment with biologic disease-modifying antirheumatic drug (bDMARD) therapy need treatment options. Objective: To evaluate the effects of filgotinib vs placebo on the signs and symptoms of RA in a treatment-refractory population. Design, Setting, and Participants: A 24-week, randomized, placebo-controlled, multinational phase 3 trial conducted from July 2016 to June 2018 at 114 sites internationally, randomizing 449 adult patients (and treating 448) with moderately to severely active RA and inadequate response/intolerance to 1 or more prior bDMARDs. Interventions: Filgotinib, 200 mg (n = 148); filgotinib, 100 mg (n = 153); or placebo (n = 148) once daily; patients continued concomitant stable conventional synthetic DMARDs (csDMARDs). Main Outcomes and Measures: The primary end point was the proportion of patients who achieved 20% improvement in the American College of Rheumatology criteria (ACR20) at week 12. Secondary outcomes included week 12 assessments of low disease activity (disease activity score in 28 joints-C-reactive protein [DAS28-CRP] ≤3.2) and change in Health Assessment Questionnaire-Disability Index, 36-Item Short-Form Health Survey Physical Component, and Functional Assessment of Chronic Illness Therapy-Fatigue scores, as well as week 24 assessment of remission (DAS28-CRP <2.6) and adverse events. Results: Among 448 patients who were treated (mean [SD] age, 56 [12] years; 360 women [80.4%]; mean [SD] DAS28-CRP score, 5.9 [0.96]; 105 [23.4%] with ≥3 prior bDMARDs), 381 (85%) completed the study. At week 12, more patients receiving filgotinib, 200 mg (66.0%) or 100 mg (57.5%), achieved ACR20 response (placebo, 31.1%; difference vs placebo: 34.9% [95% CI, 23.5%-46.3%] and 26.4% [95% CI, 15.0%-37.9%], respectively; both P < .001), including among patients with prior exposure to 3 or more bDMARDs (70.3%, 58.8%, and 17.6%, respectively; difference vs placebo: 52.6% [95% CI, 30.3%-75.0%] for filgotinib, 200 mg, and 41.2% [95% CI, 17.3%-65.0%] for filgotinib, 100 mg; both P < .001). The most common adverse events were nasopharyngitis (10.2%) for filgotinib, 200 mg; headache, nasopharyngitis, and upper respiratory infection (5.9% each) for filgotinib, 100 mg; and RA (6.1%) for placebo. Four uncomplicated herpes zoster cases and 1 retinal vein occlusion were reported with filgotinib; there were no opportunistic infections, active tuberculosis, malignancies, gastrointestinal perforations, or deaths. Conclusions and Relevance: Among patients with active RA who had an inadequate response or intolerance to 1 or more bDMARDs, filgotinib, 100 mg daily or 200 mg daily, compared with placebo resulted in a significantly greater proportion achieving a clinical response at week 12. However, further research is needed to assess longer-term efficacy and safety. Trial Registration: ClinicalTrials.gov Identifier: NCT02873936.

TGFß responsive tyrosine phosphatase promotes rheumatoid synovial fibroblast invasiveness.

OBJECTIVE: In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) that line joint synovial membranes aggressively invade the extracellular matrix, destroying cartilage and bone. As signal transduction in FLS is mediated through multiple pathways involving protein tyrosine phosphorylation, we sought to identify protein tyrosine phosphatases (PTPs) regulating the invasiveness of RA FLS. We describe that the transmembrane receptor PTPκ (RPTPκ), encoded by the transforming growth factor (TGF) ß-target gene, PTPRK, promotes RA FLS invasiveness. METHODS: Gene expression was quantified by quantitative PCR. PTP knockdown was achieved using antisense oligonucleotides. FLS invasion and migration were assessed in transwell or spot assays. FLS spreading was assessed by immunofluorescence microscopy. Activation of signalling pathways was analysed by Western blotting of FLS lysates using phosphospecific antibodies. In vivo FLS invasiveness was assessed by intradermal implantation of FLS into nude mice. The RPTPκ substrate was identified by pull-down assays. RESULTS: PTPRK expression was higher in FLS from patients with RA versus patients with osteoarthritis, resulting from increased TGFB1 expression in RA FLS. RPTPκ knockdown impaired RA FLS spreading, migration, invasiveness and responsiveness to platelet-derived growth factor, tumour necrosis factor and interleukin 1 stimulation. Furthermore, RPTPκ deficiency impaired the in vivo invasiveness of RA FLS. Molecular analysis revealed that RPTPκ promoted RA FLS migration by dephosphorylation of the inhibitory residue Y527 of SRC. CONCLUSIONS: By regulating phosphorylation of SRC, RPTPκ promotes the pathogenic action of RA FLS, mediating cross-activation of growth factor and inflammatory cytokine signalling by TGFß in RA FLS.

Phosphoinositide 3-kinase δ regulates migration and invasion of synoviocytes in rheumatoid arthritis.

Cartilage destruction mediated by invasive fibroblast-like synoviocytes (FLS) plays a central role in pathogenesis of rheumatoid arthritis (RA). Increased cell migration and degradation of extracellular matrix are fundamental to these processes. The class I PI3Ks control cell survival, proliferation, and migration, which might be involved in cartilage damage in RA. PI3Kδ isoform was recently identified as a key regulator of FLS growth and survival, suggesting that it could contribute to synoviocyte aggressive behavior. Therefore, we assessed the role of PI3Kδ in RA synoviocyte migration and invasion. We observed that PI3Kδ inhibition or small interfering RNA knockdown decreased platelet-derived growth factor (PDGF)-mediated migration and invasion of FLS. We then showed that PI3Kδ regulates the organization of actin cytoskeleton and lamellipodium formation during PDGF stimulation. To gain insight into molecular mechanisms, we examined the effect of PI3Kδ inhibition on Rac1/PAK, FAK, and JNK activation. Our studies suggest that Rac1/PAK is key target of PDGF-mediated PI3Kδ signaling, whereas FAK and JNK are not involved. Thus, PI3Kδ contributes to multiple aspects of the pathogenic FLS behavior in RA. These observations, together with previous findings that PI3Kδ regulates FLS growth and survival, suggest that PI3Kδ inhibition could be chondroprotective in RA by modulating synoviocyte growth, migration, and invasion.

Novel phosphoinositide 3-kinase δ,γ inhibitor: potent anti-inflammatory effects and joint protection in models of rheumatoid arthritis.

Phosphoinositide 3-kinases γ and δ (PI3Kγ and PI3Kδ) are expressed in rheumatoid arthritis (RA) synovium and regulate innate and adaptive immune responses. We determined the effect of a potent PI3Kδ,γ inhibitor, IPI-145, in two preclinical models of RA. IPI-145 was administered orally in rat adjuvant-induced arthritis (AA) and intraperitoneally in mouse collagen-induced arthritis (CIA). Efficacy was assessed by paw swelling, clinical scores, histopathology and radiography, and microcomputed tomography scanning. Gene expression and Akt phosphorylation in joint tissues were determined by quantitative real-time polymerase chain reaction and Western blot analysis. Serum concentrations of anti-type II collagen (CII) IgG and IgE were measured by immunoassay. T-cell responses to CII were assayed using thymidine incorporation and immunoassay. IPI-145 significantly reduced arthritis severity in both RA models using dosing regimens initiated before onset of clinical disease. Treatment of established arthritis with IPI-145 in AA, but not CIA, significantly decreased arthritis progression. In AA, histology scores, radiographic joint damage, and matrix metalloproteinase (MMP)-13 expression were reduced in IPI-145-treated rats. In CIA, joint histology scores and expression of MMP-3 and MMP-13 mRNA were lower in the IPI-145 early treatment group than in the vehicle group. The ratio of anti-CII IgG2a to total IgG in CIA was modestly reduced. Interleukin-17 production in response to CII was decreased in the IPI-145-treated group, suggesting an inhibitory effect on T-helper cell 17 differentiation. These data show that PI3Kδ,γ inhibition suppresses inflammatory arthritis, as well as bone and cartilage damage, through effects on innate and adaptive immunity and that IPI-145 is a potential therapy for RA.

Protein tyrosine phosphatase expression profile of rheumatoid arthritis fibroblast-like synoviocytes: a novel role of SH2 domain-containing phosphatase 2 as a modulator of invasion and survival.

OBJECTIVE: The fibroblast-like synoviocytes (FLS) in the synovial intimal lining of the joint are key mediators of inflammation and joint destruction in rheumatoid arthritis (RA). In RA, these cells aggressively invade the extracellular matrix, producing cartilage-degrading proteases and inflammatory cytokines. The behavior of FLS is controlled by multiple interconnected signal transduction pathways involving reversible phosphorylation of proteins on tyrosine residues. However, little is known about the role of the protein tyrosine phosphatases (PTPs) in FLS function. This study was undertaken to explore the expression of all of the PTP genes (the PTPome) in FLS. METHODS: A comparative screening of the expression of the PTPome in FLS from patients with RA and patients with osteoarthritis (OA) was conducted. The functional effect on RA FLS of SH2 domain-containing phosphatase 2 (SHP-2), a PTP that was up-regulated in RA, was then analyzed by knockdown using cell-permeable antisense oligonucleotides. RESULTS: PTPN11 was overexpressed in RA FLS compared to OA FLS. Knockdown of PTPN11, which encodes SHP-2, reduced the invasion, migration, adhesion, spreading, and survival of RA FLS. Additionally, signaling in response to growth factors and inflammatory cytokines was impaired by SHP-2 knockdown. RA FLS that were deficient in SHP-2 exhibited decreased activation of focal adhesion kinase and mitogen-activated protein kinases. CONCLUSION: These findings indicate that SHP-2 has a novel role in mediating human FLS function and suggest that it promotes the invasiveness and survival of RA FLS. Further investigation may reveal SHP-2 to be a candidate therapeutic target for RA.

Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis.

Rheumatoid arthritis (RA) remains a significant unmet medical need despite significant therapeutic advances. The pathogenesis of RA is complex and includes many cell types, including T cells, B cells, and macrophages. Fibroblast-like synoviocytes (FLS) in the synovial intimal lining also play a key role by producing cytokines that perpetuate inflammation and proteases that contribute to cartilage destruction. Rheumatoid FLS develop a unique aggressive phenotype that increases invasiveness into the extracellular matrix and further exacerbates joint damage. Recent advances in understanding the biology of FLS, including their regulation regulate innate immune responses and activation of intracellular signaling mechanisms that control their behavior, provide novel insights into disease mechanisms. New agents that target FLS could potentially complement the current therapies without major deleterious effect on adaptive immune responses.

PI3 kinase δ is a key regulator of synoviocyte function in rheumatoid arthritis.

Class I phosphoinositide 3 kinase (PI3K) δ is a promising therapeutic target for rheumatoid arthritis (RA) because of its contribution to leukocyte biology. However, its contribution in fibroblasts has not been studied as a mechanism that contributes to efficacy. We investigated the expression and function of PI3Kδ in synovium and cultured fibroblast-like synoviocytes (FLS). Immunohistochemistry demonstrated that PI3Kδ is highly expressed in RA synovium, especially in the synovial lining. Using quantitative PCR and Western blot analysis, we found that PI3Kδ mRNA and protein expression is higher in RA than in osteoarthritis (OA) synovium. PI3Kδ was also expressed in cultured FLS, along with PI3Kα and PI3Kß, whereas PI3Kγ was not detectable. PI3Kδ mRNA expression was selectively induced by inflammatory cytokines tumor necrosis factor (TNF) and interleukin-1 (IL-1) but not by growth factors platelet-derived growth factor (PDGF) and transforming growth factor ß (TGFß). The use of inhibitors that block individual PI3K isoforms, including the novel selective PI3Kδ inhibitor INK007, showed that PI3Kδ is required for PDGF- and TNF-induced Akt activation. PI3Kδ inhibition also diminished PDGF-mediated synoviocyte growth and sensitized cells to H(2)O(2)-induced apoptosis. These data are the first documentation of increased PI3Kδ expression in both RA synovium and cultured synoviocytes. Furthermore, these are the first data demonstrating that PI3Kδ is a major regulator of PDGF-mediated fibroblast growth and survival via Akt. Thus, targeting PI3Kδ in RA could modulate synoviocyte function via anti-inflammatory and disease-altering mechanisms.

Benefit of Filgotinib, a JAK1 Preferential Inhibitor, in Rheumatoid Arthritis Patients with Previous Rapid Radiographic Progression: Post Hoc Analysis of Two Trials.

INTRODUCTION: We conducted a post hoc analysis of efficacy and safety of filgotinib stratified by estimated radiographic progression rate before baseline (BL) in patients with rheumatoid arthritis (RA) who had inadequate response to methotrexate (MTX; FINCH 1; NCT02889796) or were naïve to it (FINCH 3; NCT02886728). METHODS: Radiographic progression rate was BL-Modified Total Sharp Score (mTSS) divided by RA duration (BL mTSS/year); estimated rapid radiographic progression (e-RRP) was BL change in mTSS/year ≥ 5; and estimated nonrapid radiographic progression (e-NRRP) was BL mTSS/year < 5. Efficacy and safety were compared between subgroups. All p-values are nominal. RESULTS: In FINCH 1 and FINCH 3, 558/1755 (31.8%) and 787/1249 (63.0%) patients, respectively, had BL e-RRP. BL characteristics were generally similar between subgroups within each trial. At week (W) 24, in FINCH 1, proportions achieving a Disease Activity Score 28 for rheumatoid arthritis with C-reactive protein < 2.6 were significantly greater with filgotinib 200 (FIL200) and 100 mg (FIL100) versus placebo among e-RRP and e-NRRP subgroups. In each study, proportions of FIL-treated patients achieving Clinical Disease Activity Index ≤ 2.8 and Simple Disease Activity Index ≤ 3.3 were similar between subgroups. In FINCH 3, disease activity measures were at least numerically improved among patients receiving FIL versus MTX monotherapy. At W24, mTSS changes from BL (CFB) were greater among patients with e-RRP in FINCH 1 and FINCH 3 versus e-NRRP (0.81 versus 0.19, p = 0.001; 0.67 versus 0.25, p = 0.31, respectively). At W52, in FINCH 1, mTSS CFBs were smaller among e-RRP patients treated with FIL200 (0.40; p < 0.001) and FIL100 (0.77; p = 0.024) versus adalimumab (ADA; 1.46). In FINCH 3 at W52, mTSS CFBs were significantly smaller with FIL200 versus MTX among e-RRP patients. Rates of treatment-emergent adverse events (AEs) were comparable between subgroups and across treatment arms. CONCLUSIONS: Patients with previous e-RRP who received standard care tended to progress radiographically. FIL200 demonstrated persistent, consistent benefit for disease activity control among e-RRP and e-NRRP subgroups, and AE profiles were similar between subgroups. Although filgotinib efficacy was somewhat reduced among patients with e-RRP, filgotinib treatment slowed radiographic progression in both subgroups. TRIAL REGISTRATION: Clinicaltrials.gov NCT02889796, NCT02886728.

Efficacy and Safety of Filgotinib in Patients with High Risk of Poor Prognosis Who Showed Inadequate Response to MTX: A Post Hoc Analysis of the FINCH 1 Study.

INTRODUCTION: This exploratory analysis of FINCH 1 (NCT02889796) examined filgotinib (FIL) efficacy and safety in a subgroup of patients with rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX; MTX-IR) who had four poor prognostic factors (PPFs). METHODS: Patients with MTX-IR received placebo up to week (W)24 or FIL200 mg, FIL100 mg, or adalimumab up to W52; all received MTX. Efficacy and safety data were stratified by four PPFs versus fewer than four PPFs: seropositivity, high-sensitivity C-reactive protein (CRP) ≥ 6 mg/L, Disease Activity Score in 28 joints with CRP > 5.1, and erosions on X-rays. RESULTS: At baseline, 687/1755 patients had four PPFs. At W12, whether with four PPFs or fewer than four PPFs, response rates on all American College of Rheumatology (ACR) measures were significantly greater with FIL200 and FIL100 versus placebo. At W52, FIL200 ACR20/50/70 response rates remained at least numerically higher versus adalimumab in both subgroups. At W52, FIL200 reduced modified total Sharp score (mTSS) change versus adalimumab in patients with four or fewer than four PPFs. CONCLUSIONS: In high-risk (four PPFs) patients with MTX-IR RA, FIL200 and FIL100 showed similar reductions in disease activity versus placebo at W12 as in patients with fewer than four PPFs. mTSS in patients receiving FIL200 changed little from W24 to W52, while that in patients receiving FIL100 progressed comparably to patients who received adalimumab. Tolerability was comparable across treatment arms and subgroups.