Abatacept (Orencia®)
Drug class: T-cell co-stimulation modulators
Mechanism of Action
Abatacept is a T-cell co-stimulation modulator that binds to CD80/CD86, inhibiting interaction with the CD28 receptor on T cells. This interrupts co-stimulation and T-cell activation, inhibiting major pro-inflammatory cytokines, specifically TNF-α, interferon-γ, and IL-2 (1).
Approved Indications
Adults with moderate to severe active rheumatoid arthritis (RA) (1)
Pediatric patients (≥2 years) with moderate to severe active polyarticular juvenile idiopathic arthritis (pJIA) and active psoriatic arthritis (PsA) (1)
Prophylaxis in adults and pediatric patients (> 2 years): acute graft-versus-host disease (aGVHD), undergoing hematopoietic stem cell transplantation (HSCT) from a matched or 1 allele‑mismatched unrelated donor (in combination with a calcineurin inhibitor and methotrexate) (1).
Dosage and administration
Adult RA and Adult PsA
Intravenous (IV) (< 60kg: 500mg; 60 to 100kg: 750 mg; >100 kg: 1000mg) at 0, 2, and 4 weeks, and every 4 weeks thereafter, as a 30-minute infusion.
Adult RA
Subcutaneous (SC) within a day of a single IV, 125 mg once weekly; patients switch from IV to SC, administer the first SC dose for the next scheduled IV (1)
Pediatric patients (≥6 years) pJIA
IV (<75 kg: 10 mg/kg ;≥75 kg:750 mg (maximum dose 1,000 mg), as a 30-minute infusion. Subsequent infusions at 2 and 4 weeks and every 4 weeks thereafter.
Pediatric patients (≥2 years) pJIA and PsA
SC (10 to < 25 kg: 50 mg; 25 to <50 kg: 87.5 mg; ≥50 kg: 125 mg)
Adult PsA
SC (125 mg once weekly without an IV loading dose; patients switch from IV to SC, administer the first SC dose for the next scheduled IV (1)
Pediatric patients (>6years) Prophylaxis of aGVHD
IV (10 mg/kg dose (maximum dose 1,000 mg) as a 60-minute infusion on the day before transplantation, followed by a dose on Day 5, 14, and 28 after transplant.
Pediatric patients (2 to<6 years)
IV (15 mg/kg dose as a 60-minute infusion on the day before transplantation, followed by a 12 mg/kg dose as a 60-minute infusion on Day 5, 14, and 28 after transplant (1)
Key clinical benefits
Slowed radiographic joint progression
Improved disease remission
Key clinical trials
AMPLIFIED
In a randomized, single blind Phase 3 study, investigators enrolled 338 patients with early rheumatoid arthritis (RA) and inadequate response to methotrexate. All patients were positive for anti citrullinated protein antibodies (ACPA), rheumatoid factor (RF), and shared epitope (SE). At Week 24, ACR50 response rates were comparable between treatment groups: 59% with abatacept and 60% with adalimumab (adjusted odds ratio [95% CI]: 1.0 [0.6–1.6]). Both agents showed similar safety profiles, with comparable rates of adverse events (AEs) and serious AEs (2).
ARIAA
In this randomized trial, investigators evaluated subcutaneous abatacept 125 mg in 98 adults with anti citrullinated protein antibody (ACPA) positivity and joint pain, but without swelling, osteitis, synovitis, or tenosynovitis on hand MRI. Patients entered a 12 month drug free observation phase following treatment. After 6 months of abatacept therapy, MRI inflammation decreased significantly (absolute difference 26.5%; 95% CI 5.9–45.6; p=0.014). Progression to RA was observed in only 8% of patients compared with 35% in the placebo group (HR 0.14 [0.04–0.47]; p=0.0016).
At one year, 51% of abatacept treated patients demonstrated improved MRI inflammation, while 35% progressed to RA, compared with 24% (p=0.012) and 57% (p=0.018), respectively, in the placebo group. Serious adverse events were reported, though no deaths occurred (4).
GVHD
A randomized Phase 2 trial enrolled 142 adults and children undergoing unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) to receive abatacept in combination with a calcineurin inhibitor (CNI) and methotrexate (MTX). Although the primary endpoint of severe GVHD free survival (SGFS) at Day 180 was not achieved, abatacept demonstrated clinical benefit. Rates of grade 3–4 acute GVHD (aGVHD) were lower with abatacept (6.8%) compared with placebo (14.8%) (p=0.13; HR=0.45), and in HLA 8/8 matched transplants, SGFS was 93.2% versus 82% with placebo. In HLA 7/8 matched transplants, abatacept + CNI + MTX markedly reduced grade 3–4 aGVHD (2.3% vs 30.2%; p<0.001) and improved SGFS (97.7% vs 58.7%; p<0.001) compared with placebo (5).
Supporting real world evidence confirmed improved overall survival, with abatacept + CNI + MTX achieving 98% (95% CI: 78–100) compared with 75% (95% CI: 67–82) for CNI + MTX alone in URD HSCT patients (216) (6).
ASTRAEA
This is a randomized Phase 3 trial involving 424 patients with psoriatic arthritis evaluated subcutaneous abatacept. The study achieved its primary endpoint, demonstrating a significantly higher American College of Rheumatology 20 (ACR20) response at Week 24 compared with placebo (39.4% vs 22.3%; p<0.001). In addition, abatacept produced a modest improvement in psoriasis lesions, supporting its role in managing both joint and skin manifestations of psoriatic arthritis (7).
JIA2
In this Phase 3 open label, single arm study, investigators evaluated subcutaneous abatacept in 219 patients with polyarticular course juvenile idiopathic arthritis (JIA). The primary endpoint was achieved at Month 4, with patients demonstrating JIA ACR 30, 50, 70, 90, and 100 responses. Disease activity, measured by the Juvenile Arthritis Disease Activity Score in 71 joints using C reactive protein (JADAS 71–CRP), showed marked improvement from baseline to Month 4. In cohort 1, scores decreased from 21.0 (13.5, 30.3) to 4.6 (2.1, 9.4), and in cohort 2, from 18.1 (14.0, 23.1) to 2.1 (0.3, 4.4). These improvements were successfully maintained through 24 months, supporting the sustained efficacy of abatacept in this patient population (8).
Common Adverse Events
In RA
Headache (1)
Upper respiratory tract infection (1)
Nasopharyngitis (1)
Nausea (1)
In prophylaxis of aGVHD
Acute kidney injury (1)
Anemia (1)
CMV reactivation/CMV infection (1)
Decreased CD4 lymphocytes (1)
Epistaxis (1)
Hypermagnesemia (1)
Hypertension (1)
Pneumonia (1)
Pyrexia (1)
Contraindications
None (1)
Special Notes for Clinician
Clinicians should be aware of the increased risk of infections and serious infections with concomitant use of abatacept. Patients should be screened for hypersensitivity, anaphylaxis, recurrent infections, and underlying conditions, with therapy discontinued if serious infections develop. Pre treatment screening should include latent tuberculosis, viral hepatitis, and chronic obstructive pulmonary disease (COPD). Vaccinations should be updated prior to initiating therapy, and live vaccines should be avoided during treatment or within three months of discontinuation. In patients receiving abatacept for acute GVHD prophylaxis, monitoring for cytomegalovirus (CMV) and Epstein–Barr virus (EBV) reactivation is recommended (1).
Abbreviations
CD: cluster of differentiation; TNF: tumor necrosis factor; RA: rheumatoid arthritis; pJIA: polyarticular juvenile idiopathic arthritis; PsA: psoriatic arthritis; aGVHD: acute graft-versus-host disease; IV: intravenous; SC: subcutaneous; HSCT: hematopoietic stem cell transplantation; ACPA: anti-citrullinated protein antibodies; RF: rheumatoid factor, SE: shared epitope; URD: unrelated-donor; CNI: calcineurin inhibitor; MTX: methotrexate; American College of Rheumatology: ACR; JADAS-71–CRP: Juvenile Arthritis Disease Activity Score; COPD: Chronic obstructive pulmonary disease; CMV: cytomegalovirus; EMV: Epstein-Barr virus
References
ORENCIA® (abatacept) prescribing information. Available at: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://packageinserts.
bms.com/pi/pi_orencia.pdf Accessed on 2 October 2026.
Emery P, Weinblatt ME, Bykerk VP, et al. A head-to-head comparison of abatacept and adalimumab in adults with early and dual seropositive rheumatoid arthritis plus HLA-DRB1 shared epitope: results from the randomised phase 3 AMPLIFIED trial. Ann Rheum Dis. 2026;10.
Cope AP, Jasenecova M, Vasconcelos JC, et al. Long-term outcomes of abatacept in individuals at risk of developing rheumatoid arthritis (ALTO): a randomised, double-blind, placebo-controlled trial. Lancet Rheumatol. 2026 Mar 1;8(3):e171-80.
Rech J, Tascilar K, Hagen M, et al. Abatacept inhibits inflammation and onset of rheumatoid arthritis in individuals at high risk (ARIAA): a randomised, international, multicentre, double-blind, placebo-controlled trial. The Lancet. 2024; 2;403(10429):850-9.
Watkins B, Qayed M, McCracken C, et al. Phase II trial of costimulation blockade with abatacept for prevention of acute GVHD. J Clin Oncol 2021, 10;39(17):1865-77.
Norsworthy KJ, Rivera DR, Wynne J, et al. FDA Approval Summary: Abatacept for the Prophylaxis of Acute GVHD. Clin Cancer Res, 2025, 1;31(15):3118-23.
Mease PJ, Gottlieb AB, Van Der Heijde D, et al. Efficacy and safety of abatacept, a T-cell modulator, in a randomised, double-blind, placebo-controlled, phase III study in psoriatic arthritis. Ann Rheum Dis. 2017, 76(9):1550-8.
Brunner HI, Tzaribachev N, Vega‐Cornejo G, et al. Subcutaneous abatacept in patients with polyarticular‐course juvenile idiopathic arthritis: results from a phase III open‐label study. Arthritis & rheumatology. 2018, 70(7):1144-54.
About the Author
Jaimee George holds a PhD in Microbiology and has published extensively in peer reviewed journals. As a scientific writer, she has developed systematic reviews, book chapters, review articles, and original research papers. Her professional interests include regulatory writing, medical communication tools, and case report development.
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