Abatacept and Guselkumab: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 16, 2026 · Source data updated Jul 16, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Abatacept
Guselkumab
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Both of these medicines calm down your immune system, just in different ways. Abatacept (Orencia) works on your immune T-cells, and guselkumab blocks a signal called IL-23 that drives inflammation. On their own, each one helps conditions like arthritis or psoriasis. But taking two immune-lowering biologics together can leave you more open to serious infections, and studies with similar combinations didn't show any extra benefit for it.
The good news is your care team knows about this. That's why doctors usually don't recommend using both at once. Please don't stop or change anything on your own, just talk with your doctor or pharmacist so they can pick the safest plan for you.
Effect: Additive immunosuppression raising the risk of serious infection, with no added therapeutic benefit expected.
- Direction/mechanism: Both are immunomodulatory biologics (abatacept, a selective T-cell costimulation modulator; guselkumab, an IL-23 inhibitor). Neither is a prodrug; the concern is pharmacodynamic overlap, not CYP/transporter kinetics. Exact mechanism unknown.
- Evidence: Theoretical, extrapolated from controlled trials of abatacept with TNF antagonists showing increased serious infection without added benefit.
- Onset: Unspecified.
- Management: Concurrent use with other RA/PsA biologics is not recommended. If transitioning between agents, monitor for signs and symptoms of infection.
What happens
An increased risk of infection
Interaction Deep Dive
In controlled clinical studies, giving abatacept together with tumor necrosis factor (TNF) antagonists was shown to raise the risk of serious infection while offering no extra therapeutic benefit. Available data are inadequate to assess the safety and efficacy of abatacept when combined with anakinra or with biologic agents used for rheumatoid arthritis or psoriatic arthritis, so using these drugs at the same time is not advised. Patients switching from TNF antagonist therapy to abatacept should be watched for signs of infection1.
Why it happens (mechanism)
Unknown
How to manage this interaction
What your care team usually does: Combining abatacept with another immune-modulating biologic like guselkumab is generally not recommended because of the higher infection risk. Your team will typically choose one biologic rather than using both together.
- Keep taking your medicines exactly as prescribed and don't stop either one on your own.
- If you are switching from one biologic to abatacept (or the other way), your team may watch you more closely for signs of infection.
- Ask your pharmacist or prescriber which single agent is best for your condition.
Call your provider promptly if you notice fever, chills, a lingering cough, or other signs of infection.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Taking abatacept together with etanercept produced no extra efficacy but raised the risk of serious infection when compared with etanercept used on its own. In a 1-year randomized study (N=121) that was followed by an open-label long-term extension (LTE; n=80), patients with rheumatoid arthritis who were already receiving etanercept 25 mg twice/week continued that etanercept and were randomized to receive either abatacept 2 mg/kg IV on days 1, 15, and 30, and then every 4 weeks (n=85) or placebo (n=36). After finishing the double-blind phase, patients qualified for the LTE phase, at which point the abatacept dose was raised to roughly 10 mg/kg. At 6 months, the 2 mg/kg abatacept group demonstrated no significant improvement over the placebo group in modified American College of Rheumatology 20% (ACR20; 48.2% vs 30.6%) or ACR50 (25.9% vs 19.4%) response rates, although there was a significant difference in modified ACR70 rates (10.6% vs 0%). At 1 year, no significant differences were found in ACR20, 50, or 70 response rates between the two groups. Serious adverse events occurred more often in the 2 mg/kg abatacept group (16.5%) at one year and in the 10 mg/kg abatacept group after 2 years of LTE (32.5%) than in the placebo group (2.8%). Serious infections at 1 year were reported in 3.5% of the 2 mg/kg abatacept group and 0% of the placebo group 2.
b) In controlled clinical trials involving adults with active rheumatoid arthritis who received abatacept together with a tumor necrosis factor (TNF) antagonist (n=204) versus TNF antagonist therapy by itself (n=134), the rate of infection (63% vs 43%, respectively) and of serious infection (4.4% vs 0.8%, respectively) was higher with the combined therapy; in addition, the combined therapy offered no added benefit 1.
Common questions
Can I take Abatacept and Guselkumab together?
Using abatacept and guselkumab together is generally not recommended because two immune-lowering biologics raise the risk of serious infection without added benefit; talk with your doctor or pharmacist about using just one. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abatacept and Guselkumab interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Abatacept and Guselkumab interaction managed?
What your care team usually does: Combining abatacept with another immune-modulating biologic like guselkumab is generally not recommended because of the higher infection risk. Your team will typically choose one biologic rather than using both together. Keep taking your medicines exactly as prescribed and don't stop either one on your own. If you are switching from one biologic to abatacept (or t… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Abatacept or Guselkumab need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: ORENCIA(R) intravenous, subcutaneous injection, abatacept intravenous, subcutaneous injection. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2020. DailyMed
- Weinblatt M, Schiff M, Goldman A, et al: Selective costimulation modulation using abatacept in patients with active rheumatoid arthritis while receiving etanercept: a randomised clinical trial. Ann Rheum Dis 2007; 66(2):228-234. PubMed
Keep reading about Abatacept
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