Brodalumab and Abatacept: 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
Brodalumab
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.
Abatacept (Orencia) and brodalumab both calm down your immune system, just in different ways. Abatacept quiets certain immune cells, while brodalumab blocks an inflammation signal called IL-17. When two immune-lowering biologics are used together, your body can have a harder time fighting off germs, so the main worry here is a higher chance of serious infection. Studies with abatacept plus similar biologics also showed no extra benefit from combining them.
The good news is this is very manageable. Doctors generally avoid using two of these drugs at the same time. Please don't stop either one on your own. Just talk with your doctor or pharmacist so they can pick the safest plan for you.
Effect: Additive immunosuppression, increasing risk of serious infection with no added therapeutic benefit.
- Mechanism: Unknown/pharmacodynamic. Abatacept (T-cell costimulation modulator) plus brodalumab (IL-17RA antagonist) produce overlapping immunosuppression. Neither is a prodrug; this is a PD, not PK/CYP, interaction.
- Direction: Combined effect heightens infection risk.
- Evidence: Theoretical; extrapolated from trials of abatacept with TNF antagonists and other biologics.
- Onset: Unspecified.
- Management: Concurrent abatacept plus another RA/PsA biologic is not recommended. If transitioning off one agent, monitor for signs and symptoms of infection.
What happens
An increased risk of infection
Interaction Deep Dive
Data from controlled clinical trials showed that giving abatacept together with tumor necrosis factor (TNF) antagonists raised the likelihood of serious infection while offering no extra therapeutic benefit. Because available data are inadequate to assess how safe and effective abatacept is when combined with anakinra or with biologics used for rheumatoid arthritis or psoriatic arthritis, using these drugs at the same time is not advised. Patients should be watched for indications of infection during the switch from TNF antagonist treatment to abatacept1.
Why it happens (mechanism)
Unknown
How to manage this interaction
What your care team usually does:
- Generally avoids using abatacept and brodalumab (or another arthritis/psoriasis biologic) at the same time, since combining them raises infection risk without added benefit.
- If you are switching from one biologic to the other, watches you closely for signs of infection.
What you can do:
- Keep taking your medications exactly as prescribed, and do not stop or change either one on your own.
- Tell your pharmacist or doctor that you may be on both so they can confirm the safest plan.
- Report fever, chills, cough, sores, or any signs of infection promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Taking abatacept together with etanercept provided no extra efficacy but raised the risk of serious infection when compared with etanercept used by itself. 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 the 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 the double-blind phase ended, patients could enter the LTE phase, at which point the abatacept dose was raised to approximately 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 in ACR20, 50, or 70 response rates were seen 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 noted 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 those receiving TNF antagonist therapy on its own (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; furthermore, the combined therapy offered no additional benefit 1.
Common questions
Can I take Brodalumab and Abatacept together?
Using abatacept and brodalumab together can raise your risk of serious infection with no added benefit, so this combination is generally not recommended. Don't change anything yourself; check with your doctor or pharmacist and watch for signs of infection. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Brodalumab and Abatacept 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 Brodalumab and Abatacept interaction managed?
What your care team usually does: Generally avoids using abatacept and brodalumab (or another arthritis/psoriasis biologic) at the same time, since combining them raises infection risk without added benefit. If you are switching from one biologic to the other, watches you closely for signs of infection. What you can do: Keep taking your medications exactly as prescribed, and do not stop or change… 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 Brodalumab or Abatacept 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
Keep reading about Brodalumab
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