Abatacept Pharmacokinetics and Exposure Response in Patients Hospitalized With COVID-19: A Secondary Analysis of the ACTIV-1 IM Randomized Clinical Trial.

Importance: The pharmacokinetics of abatacept and the association between abatacept exposure and outcomes in patients with severe COVID-19 are unknown. Objective: To characterize abatacept pharmacokinetics, relate drug exposure with clinical outcomes, and evaluate the need for dosage adjustments. Design, Setting, and Participants: This study is a secondary analysis of data from the ACTIV-1 (Accelerating COVID-19 Therapeutic Interventions and Vaccines) Immune Modulator (IM) randomized clinical trial conducted between October 16, 2020, and December 31, 2021. The trial included hospitalized adults who received abatacept in addition to standard of care for treatment of COVID-19 pneumonia. Data analysis was performed between September 2022 and February 2024. Exposure: Single intravenous infusion of abatacept (10 mg/kg with a maximum dose of 1000 mg). Main Outcomes and Measures: Mortality at day 28 was the primary outcome of interest, and time to recovery at day 28 was the secondary outcome. Drug exposure was assessed using the projected area under the serum concentration time curve over 28 days (AUC0-28). Logistic regression modeling was used to analyze the association between drug exposure and 28-day mortality, adjusted for age, sex, and disease severity. The association between time to recovery and abatacept exposure was examined using Fine-Gray modeling with death as a competing risk, and was adjusted for age, sex, and disease severity. Results: Of the 509 patients who received abatacept, 395 patients with 848 serum samples were included in the population pharmacokinetic analysis. Their median age was 55 (range, 19-89) years and most (250 [63.3%]) were men. Abatacept clearance increased with body weight and more severe disease activity at baseline. Drug exposure was higher in patients who survived vs those who died, with a median AUC0-28 of 21 428 (range, 8462-43 378) mg × h/L vs 18 262 (range, 9628-27 507) mg × h/L (P < .001). Controlling for age, sex, and disease severity, an increase of 5000 units in AUC0-28 was associated with lower odds of mortality at day 28 (OR, 0.52 [95% CI, 0.35-0.79]; P = .002). For an AUC0-28 of 19 400 mg × h/L or less, there was a higher probability of recovery at day 28 (hazard ratio, 2.63 [95% CI, 1.70-4.08] for every 5000-unit increase; P < .001). Controlling for age, sex, and disease severity, every 5000-unit increase in AUC0-28 was also associated with lower odds of a composite safety event at 28 days (OR, 0.46 [95% CI, 0.33-0.63]; P < .001). Using the dosing regimen studied in the ACTIV-1 IM trial, 121 of the 395 patients (30.6%) would not achieve an abatacept exposure of at least 19 400 mg × h/L, particularly at the extremes of body weight. Using a modified, higher-dose regimen, only 12 patients (3.0%) would not achieve the hypothesized target abatacept exposure. Conclusions and Relevance: In this study, patients who were hospitalized with severe COVID-19 and achieved higher projected abatacept exposure had reduced mortality and a higher probability of recovery with fewer safety events. However, abatacept clearance was high in this population, and the current abatacept dosing (10 mg/kg intravenously with a maximum of 1000 mg) may not achieve optimal exposure in all patients. Trial Registration: ClinicalTrials.gov Identifier: NCT04593940.

From the Clinical to the Bench: Exploring the Insulin Modulation Effects of Tacrolimus and Belatacept.

Calcineurin inhibitors (CNIs) are critical in preventing rejection posttransplantation but pose an increased risk of post-transplant diabetes (PTD). Recent studies show that late conversion from CNIs to belatacept, a costimulation blocker, improves HbA1c in kidney transplant recipients with PTD or de novo diabetes. This study investigates whether the observed effects on PTD stem solely from CNI withdrawal or if belatacept influences PTD independently. The study assessed the impact of tacrolimus and belatacept on insulin secretion in MIN6 cells (a beta cell line) and rat islets. Tacrolimus and belatacept were administered to the cells and islets, followed by assessments of cell viability and insulin secretion. Tacrolimus impaired insulin secretion without affecting cell viability, while belatacept showed no detrimental effects on either parameter. These findings support clinical observations of improved HbA1c upon switching from tacrolimus to belatacept. Belatacept holds promise in islet or pancreas transplantation, particularly in patients with unstable diabetes. Successful cases of islet transplantation treated with belatacept without severe hypoglycemia highlight its potential in managing PTD. Further research is needed to fully understand the metabolic changes accompanying the transition from CNIs to belatacept. Preserving insulin secretion emerges as a promising avenue for investigation in this context.

Abatacept increases T cell exhaustion in early RA individuals who carry HLA risk alleles.

Exhausted CD8 T cells (TEX) are associated with worse outcome in cancer yet better outcome in autoimmunity. Building on our past findings of increased TIGIT+KLRG1+ TEX with teplizumab therapy in type 1 diabetes (T1D), in the absence of treatment we found that the frequency of TIGIT+KLRG1+ TEX is stable within an individual but differs across individuals in both T1D and healthy control (HC) cohorts. This TIGIT+KLRG1+ CD8 TEX population shares an exhaustion-associated EOMES gene signature in HC, T1D, rheumatoid arthritis (RA), and cancer subjects, expresses multiple inhibitory receptors, and is hyporesponsive in vitro, together suggesting co-expression of TIGIT and KLRG1 may broadly define human peripheral exhausted cells. In HC and RA subjects, lower levels of EOMES transcriptional modules and frequency of TIGIT+KLRG1+ TEX were associated with RA HLA risk alleles (DR0401, 0404, 0405, 0408, 1001) even when considering disease status and cytomegalovirus (CMV) seropositivity. Moreover, the frequency of TIGIT+KLRG1+ TEX was significantly increased in RA HLA risk but not non-risk subjects treated with abatacept (CTLA4Ig). The DR4 association and selective modulation with abatacept suggests that therapeutic modulation of TEX may be more effective in DR4 subjects and TEX may be indirectly influenced by cellular interactions that are blocked by abatacept.

Overview of Rheumatoid Arthritis-Associated Interstitial Lung Disease and Its Treatment.

Interstitial lung disease (ILD) is a common pulmonary complication of rheumatoid arthritis (RA), causing significant morbidity and mortality. Optimal treatment for RA-ILD is not yet well defined. Reliable prognostic indicators are largely byproducts of prior ILD progression, including low or decreasing forced vital capacity and extensive or worsening fibrosis on imaging. In the absence of validated tools to predict treatment response, decisions about whether to initiate or augment treatment are instead based on clinical judgment. In general, treatment should be initiated in patients who are symptomatic, progressing, or at high risk of poor outcomes. Retrospective data suggest that mycophenolate mofetil, azathioprine, and rituximab are likely effective therapies for RA-ILD. Abatacept is also emerging as a potential first-line treatment option for patients with RA-ILD. Further, recent data demonstrate that immunosuppression may be beneficial even in patients with a usual interstitial pneumonia (UIP) pattern on imaging, suggesting that immunosuppression should be considered irrespective of imaging pattern. Recent randomized controlled trials have shown that antifibrotic medications, such as nintedanib and likely pirfenidone, slow forced vital capacity decline in RA-ILD. Consideration can be given to antifibrotic initiation in patients progressing despite immunosuppression, particularly in patients with a UIP pattern. Future research directions include developing tools to predict which patients will remain stable from patients who will progress, discriminating patients who will respond to treatment from nonresponders, and developing algorithms for starting immunosuppression, antifibrotics, or both as first-line therapies.

Rheumatoid arthritis: prediction of future clinically-apparent disease, and prevention.

PURPOSE OF REVIEW: This review discusses updates in the prediction and prevention of future rheumatoid arthritis (RA). RECENT FINDINGS: In individuals with musculoskeletal symptoms and elevated antibodies to citrullinated proteins (ACPA) without clinical inflammatory arthritis (IA), a 'simple' score has a positive predictive value (PPV) of ∼28% for clinical IA/RA within 1 year, and a comprehensive score (including ultrasound) has a PPV of ∼71% for clinical RA within 5 years. Controlled clinical trials in individuals at-risk for future RA have been performed using corticosteroids, rituximab, atorvastatin, methotrexate, hydroxychloroquine and abatacept. Abatacept modestly reduced rates of incident clinical RA and imaging inflammation within the trials, rituximab delayed clinical IA, and methotrexate improved function, symptoms and imaging inflammation. Vitamin D with or without omega 3 fatty acids reduced incidence of autoimmune diseases, including RA. While not proven in controlled clinical trials, observational studies suggest exercise, weight loss and smoking cessation may reduce progression to clinical RA. SUMMARY: Prediction and prevention of RA is advancing although there are no currently approved interventions for prevention. Future studies should include deeper evaluation of the pathophysiology of RA development to improve prediction and identify key pathways to target in future clinical trials, as well as develop infrastructure to support prevention-related research.

Association of HLA-DRB1 locus with treatment response to abatacept or TNF inhibitors in patients with seropositive rheumatoid arthritis.

The strongest genetic risk factor for rheumatoid arthritis (RA) has been known as HLA-DRB1 based on amino acid positions 11, 71, and 74. This study analyzed the association between specific HLA-DRB1 locus and treatment response to abatacept or TNF inhibitors (TNFi) in patients with seropositive RA. A total of 374 Korean RA patients were treated with abatacept (n = 110) or TNFi (n = 264). Associations between HLA-DRB1 and treatment response after 6 months were analyzed using multivariable logistic regression. Seropositive RA patients with HLA-DRB1 shared epitope (SE) had a favorable response to abatacept (OR = 3.67, P = 0.067) and an inversely associated response to TNFi (OR 0.57, P = 0.058) based on EULAR response criteria, but the difference was not statistically significant in comparison to those without SE. In analyses using amino acid positions of HLA-DRB1, a significant association was found between valine at amino acid position 11 of SE and good response to abatacept (OR = 6.46, P = 5.4 × 10-3). The VRA haplotype also showed a good response to abatacept (OR = 4.56, P = 0.013), but not to TNFi. Our results suggest that treatment response to abatacept or TNFi may differ depending on HLA-DRB1 locus in seropositive RA, providing valuable insights for selecting optimal therapy.

Low dose post-transplant cyclophosphamide and sirolimus induce mixed chimerism with CTLA4-Ig or lymphocyte depletion in an MHC-mismatched murine allotransplantation model.

Allogeneic hematopoietic cell transplantation (allo-HCT) offers a curative option for patients with certain non-malignant hematological diseases. High-dose post-transplant cyclophosphamide (PT-Cy) (200 mg/kg) and sirolimus (3 mg/kg), (HiC) synergistically induce stable mixed chimerism. Further, sirolimus and cytotoxic T lymphocyte-associated antigen-4 immunoglobulin (CTLA4-Ig), also known as Abatacept (Aba), promote immune tolerance and allograft survival. Here, in a major histocompatibility complex (MHC)-mismatched allo-HCT murine model, we combined Aba and/or T-cell depleting anti-Thy1.2 (Thy) with a lower dose of PT-Cy (50 mg/kg) and Sirolimus (3 mg/kg), (LoC). While mice in the LoC group showed graft rejection, the addition of Thy to LoC induced similar donor chimerism levels when compared to the HiC group. However, the addition of Aba to LoC led to graft acceptance only in younger mice. When Thy was added to the LoC+Aba setting, graft acceptance was restored in both age groups. Engrafted groups displayed significantly reduced frequencies of recipient-specific interferon-γ-producing T cells as well as an increased frequency in regulatory T cells (Tregs) except in the LoC+Aba group. Splenocytes from engrafted mice showed no proliferation upon restimulation with Balb/c stimulators. Collectively, in combination with Aba or Thy, LoC may be considered to reduce graft rejection in patients who undergo allo-HCT.

Analyzing the risk of osteoporosis and fracture in rheumatoid arthritis patients who have been treated with various biologics.

BACKGROUND: Rheumatoid arthritis (RA) is a major risk factor for osteoporosis/osteoporotic fractures. We aimed to elucidate the role of treatment choices among osteoporosis/osteoporotic fractures. METHODOLOGY: We utilized the Chang-Gung Research Database to assess the risks of osteoporosis/osteoporotic fractures among independently treated RA patients, using retrospective time-to-event outcomes analysis. RESULTS: A total of 3509 RA patients with a mean of 63.1 ± 8.6 years were analyzed. Among all, 1300 RA patients (37%) were diagnosed with newly diagnosed osteoporosis. The crude incidence of newly diagnosed osteoporosis was the highest among those treated with other conventional disease-modifying anti-rheumatic drugs (cDMARDs; 74.1 events/1000-PYs, 95%CI 66.0-82.3), followed by those with a non-treatment period (68 events/1000-PYs, 95%CI 63.1-72.9), methotrxate (MTX) monotherapy (60.7 events/1000-PYs, 95%CI 41.2-80.3), MTX plus other cDMARDs (51.9 events/1000-PYs, 95%CI 43.4-60.3), and abatacept/rituximab (48.6 events/1000-PYs, 95%CI 14.9-82.3). The lowest crude incidence was found in patients treated with anti-TNFi biologics (40.4 events/1000-PYs, 95%CI 28.6-52.2) and other biologic disease-modifying anti-rheumatic drugs (bDMARDs; 40.1 events/1000-PYs, 95%CI 8.0-72.1). A total of 270 patients (20.8%) suffered from an incident fracture during follow-ups. The crude incidence of fracture was the highest among those treated with abatacept/rituximab (49.0 events/1000-PYs, 95%CI 6.0-91.9), followed by those with non-treatment periods (24.3 events/1000-PYs, 95%CI 19.3-29.4), other cDMARDs (24.2 events/1000-PYs, 95%CI 18.1-30.2), anti-TNFi biologics (20.2 events/1000-PYs, 95%CI 8.8-31.6). Other bDMARDs (13.3 events/1000-PYs, 95%CI 0-39.2), MTX mono (12.5 events/1000-PYs, 95%CI 0.3-24.8), and MTX plus other cDMARDs (11.4 events/1000-PYs, 95%CI 5.4-17.4) were low incidences. CONCLUSION: The treatment option has emerged as a critical determinant in the context of future osteoporosis and osteoporotic fracture risks among RA. These findings offer a valuable resource for clinicians, empowering them to tailor bespoke treatment strategies for RA patients, thereby mitigating the potential for future osteoporosis and fractures.

Comparative effectiveness of biologics in patients with rheumatoid arthritis stratified by body mass index: a cohort study in a Swiss registry.

OBJECTIVES: Obesity is associated with lower treatment response in patients with rheumatoid arthritis (RA). In patients with obesity, abatacept was suggested as a preferable option to tumour necrosis factor-alpha inhibitors. We aimed to assess the comparative effectiveness of etanercept, infliximab and abatacept, compared with adalimumab, in patients with RA with obesity. Secondarily, we also investigated this in patients with overweight and normal weight for completeness. DESIGN: Observational cohort study. SETTING: Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry (1997-2019). PARTICIPANTS: Adult patients with RA from the SCQM registry who received etanercept, infliximab, abatacept or adalimumab as their first biological or targeted synthetic disease-modifying antirheumatic drug were classified based on their body mass index (BMI) at the start of that treatment in three cohorts: obese, overweight, normal weight. They were followed for a maximum of 1 year. EXPOSURE: The study exposure of interest was the patients' first biological, particularly: etanercept, infliximab and abatacept, compared with adalimumab. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary study outcome was remission within 12 months, defined as 28-joint Disease Activity Score (DAS28) <2.6. Missingness was addressed using confounder-adjusted response rate with attrition correction. Logistic regression was used to compare the effectiveness of etanercept, infliximab and abatacept versus adalimumab. Each BMI cohort was addressed and analysed separately. RESULTS: The study included 443 obese, 829 overweight and 1243 normal weight patients with RA. There were no statistically significant differences in the odds of DAS28-remission at ≤12 months for etanercept, infliximab and abatacept, compared with adalimumab, in any of the BMI cohorts. CONCLUSIONS: No differences in DAS28-remission were found between the study drugs and adalimumab as first biologic in patients with RA, independently of the BMI cohort. We did not find evidence that treatment with abatacept increased the likelihood of remission compared with adalimumab among obese patients with RA.

Prediction of ineffectiveness of biological drugs using machine learning and explainable AI methods: data from the Austrian Biological Registry BioReg.

OBJECTIVES: Machine learning models can support an individualized approach in the choice of bDMARDs. We developed prediction models for 5 different bDMARDs using machine learning methods based on patient data derived from the Austrian Biologics Registry (BioReg). METHODS: Data from 1397 patients and 19 variables with at least 100 treat-to-target (t2t) courses per drug were derived from the BioReg biologics registry. Different machine learning algorithms were trained to predict the risk of ineffectiveness for each bDMARD within the first 26 weeks. Cross-validation and hyperparameter optimization were applied to generate the best models. Model quality was assessed by area under the receiver operating characteristic (AUROC). Using explainable AI (XAI), risk-reducing and risk-increasing factors were extracted. RESULTS: The best models per drug achieved an AUROC score of the following: abatacept, 0.66 (95% CI, 0.54-0.78); adalimumab, 0.70 (95% CI, 0.68-0.74); certolizumab, 0.84 (95% CI, 0.79-0.89); etanercept, 0.68 (95% CI, 0.55-0.87); tocilizumab, 0.72 (95% CI, 0.69-0.77). The most risk-increasing variables were visual analytic scores (VAS) for abatacept and etanercept and co-therapy with glucocorticoids for adalimumab. Dosage was the most important variable for certolizumab and associated with a lower risk of non-response. Some variables, such as gender and rheumatoid factor (RF), showed opposite impacts depending on the bDMARD. CONCLUSION: Ineffectiveness of biological drugs could be predicted with promising accuracy. Interestingly, individual parameters were found to be associated with drug responses in different directions, indicating highly complex interactions. Machine learning can be of help in the decision-process by disentangling these relations.

Effectiveness of combined plasma cell therapy and costimulation blockade based desensitization regimen in heart transplant candidates.

BACKGROUND: Desensitization is one of the strategies to reduce antibodies and facilitate heart transplantation in highly sensitized patients. We describe our center's desensitization experience with combination of plasma cell (PC) depletion therapy (with proteasome inhibitor or daratumumab) and costimulation blockade (with belatacept). METHODS: We reviewed five highly sensitized patients who underwent desensitization therapy with plasma cell depletion and costimulation blockade. We evaluated the response to therapy by measuring the changes in cPRA, average MFI, and number of positive beads > 5000MFI. RESULTS: Five patients, mean age of 56 (37-66) years with average cPRA of 98% at 5000 MFI underwent desensitization therapy. After desensitization, mean cPRA decreased from 98% to 70% (p = .09), average number of beads > 5000 MFI decreased from 59 to 37 (p = .15), and average MFI of beads > 5000 MFI decreased from 16713 to 13074 (p = .26). CONCLUSION: Combined PC depletion and CoB could be a reasonable strategy for sustained reduction in antibodies in highly sensitized patients being listed for heart transplantation.

The double shared epitope: Its impact on clinical features and ultrasound findings in rheumatoid arthritis.

OBJECTIVES: The link between the HLA-DRB1 locus and the risk of rheumatoid arthritis (RA) shown in genome-wide association studies strengthens the shared epitope (SE) hypothesis. We aimed to assess the impact of the double dose of the SE (double SE) on RA and explore its clinical associations, including the response to abatacept. METHODS: We evaluated RA patients treated with csDMARDs or abatacept for HLA-DRB1 typing, clinical characteristics at baseline, and disease activity and ultrasound findings over 12 months. RESULTS: Patients with the double SE (n = 12) had significantly higher anti-citrullinated protein antibody (ACPA) titers, higher total grayscale (GS) score, and power Doppler (PD) score at baseline than patients without the double SE. Patients with the double SE exhibited reduced rates of SDAI remission and pronounced improvements in multiple disease activity between baseline and 12 months, including SDAI, CDAI, total GS score, and total PD score. When focusing on abatacept-treated patients, the decreases in SDAI, CDAI, and total PD score between baseline and 12 months were significantly larger in patients with the double SE. CONCLUSIONS: Patients with the double SE exhibited distinct characteristics, increased disease activity, and improved response to abatacept treatment.

Conversion from calcineurin inhibitors to belatacept-based immunosuppressive therapy skews terminal proliferation of non-classical monocytes and lowers lymphocyte counts.

Belatacept, a modified form of CTLA-Ig that blocks CD28-mediated co-stimulation of T cells, is an immune-suppressant that can be used as an alternative to calcineurin inhibitors (CNIs). In kidney transplant recipients, belatacept has been associated with improved renal function and reduced cardiovascular toxicity. Monocytes as well as T-lymphocytes play causal roles in the pathophysiology of atherosclerotic disease. We hypothesized that the beneficial impact of the use of belatacept over CNIs on cardiovascular risk could be partly explained by the impact of belatacept therapy on these circulating leukocytes. Hence, we phenotyped circulating leukocytes in transplanted patients with a stable renal function that were randomized between either continuation of CNI or conversion to belatacept in two international studies in which we participated. In 41 patients, we found that belatacept-treated patients consistently showed lower numbers of B-lymphocytes, T-lymphocytes as well as CD14-negative monocytes (CD14NM), especially in non-diabetic patients. Our observation that this decrease was associated to plasma concentrations of TNFα is consistent with a model where CD14NM-production of TNFα is diminished by belatacept-treatment, due to effects on the antigen-presenting cell compartment.

Long-Term Outcomes after Conversion to a Belatacept-Based Immunosuppression in Kidney Transplant Recipients.

BACKGROUND: Conversion to a belatacept-based immunosuppression is currently used as a calcineurin inhibitor (CNI) avoidance strategy when the CNI-based standard-of-care immunosuppression is not tolerated after kidney transplantation. However, there is a lack of evidence on the long-term benefit and safety after conversion to belatacept. METHODS: We prospectively enrolled 311 kidney transplant recipients from 2007 to 2020 from two referral centers, converted from CNI to belatacept after transplant according to a prespecified protocol. Patients were matched at the time of conversion to patients maintained with CNIs, using optimal matching. The primary end point was death-censored allograft survival at 7 years. The secondary end points were patient survival, eGFR, and safety outcomes, including serious viral infections, immune-related complications, antibody-mediated rejection, T-cell-mediated rejection, de novo anti-HLA donor-specific antibody, de novo diabetes, cardiovascular events, and oncologic complications. RESULTS: A total of 243 patients converted to belatacept (belatacept group) were matched to 243 patients maintained on CNIs (CNI control group). All recipient, transplant, functional, histologic, and immunologic parameters were well balanced between the two groups with a standardized mean difference below 0.05. At 7 years post-conversion to belatacept, allograft survival was 78% compared with 63% in the CNI control group ( P < 0.001 for log-rank test). The safety outcomes showed a similar rate of patient death (28% in the belatacept group versus 36% in the CNI control group), active antibody-mediated rejection (6% versus 7%), T-cell-mediated rejection (4% versus 4%), major adverse cardiovascular events, and cancer occurrence (9% versus 11%). A significantly higher rate of de novo proteinuria was observed in the belatacept group as compared with the CNI control group (37% versus 21%, P < 0.001). CONCLUSIONS: This real-world evidence study shows that conversion to belatacept post-transplant was associated with lower risk of graft failure and acceptable safety outcomes compared with patients maintained on CNIs. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Long-term Outcomes after Conversion to Belatacept, NCT04733131 .

Monocyte-derived transcriptomes explain the ineffectiveness of abatacept in rheumatoid arthritis.

BACKGROUND: The biological mechanisms underlying the differential response to abatacept in patients with rheumatoid arthritis (RA) are unknown. Here, we aimed to identify cellular, transcriptomic, and proteomic features that predict resistance to abatacept in patients with RA. METHODS: Blood samples were collected from 22 RA patients treated with abatacept at baseline and after 3 months of treatment. Response to treatment was defined by the European League Against Rheumatism (EULAR) response criteria at 3 months, and seven patients were classified as responders and the others as non-responders. We quantified gene expression levels by RNA sequencing, 67 plasma protein levels, and the expression of surface molecules (CD3, 19, and 56) by flow cytometry. In addition, three gene expression data sets, comprising a total of 27 responders and 50 non-responders, were used to replicate the results. RESULTS: Among the clinical characteristics, the number of monocytes was significantly higher in the non-responders before treatment. Cell type enrichment analysis showed that differentially expressed genes (DEGs) between responders and non-responders were enriched in monocytes. Gene set enrichment analysis, together with single-cell analysis and deconvolution analysis, identified that Toll-like receptor 5 (TLR5) and interleukin-17 receptor A (IL17RA) pathway in monocytes was upregulated in non-responders. Hepatocyte growth factor (HGF) correlated with this signature showed higher concentrations in non-responders before treatment. The DEGs in the replication set were also enriched for the genes expressed in monocytes, not for the TLR5 and IL17RA pathway but for the oxidative phosphorylation (OXPHOS) pathway. CONCLUSIONS: Monocyte-derived transcriptomic features before treatment underlie the differences in abatacept efficacy in patients with RA. The pathway activated in monocytes was the TLR5 and IL17RA-HGF signature in the current study, while it was the OXPHOS pathway in the replication set. Elevated levels of HGF before treatment may serve as a potential biomarker for predicting poor responses to abatacept. These findings provide insights into the biological mechanisms of abatacept resistance, contributing valuable evidence for stratifying patients with RA.