Abatacept vs Belatacept: side effects in FDA adverse event reports
At a glance
| Abatacept | Belatacept | |
|---|---|---|
| Drug class | Selective T Cell Costimulation Modulator | Selective T Cell Costimulation Blocker |
| Brand names | Orencia | Nulojix |
| FAERS reports | 137,367 | 4,646 |
| Serious | 60% | 76% |
| Death outcome | 9,239 | 742 |
| Boxed warning | No | Yes POST-TRANSPLANT LYMPHOPROLIFERATIVE DISORDER, OTHER MALIGNANCIES, AND SERIOUS INFECTIONS Increased risk for developing post-transplant lymphoproliferative disor |
Signals both drugs share
No strong shared signal after removing coding and lab terms.
Labeled signals distinctive to Abatacept
- None stood out among the strongest labeled signals.
Labeled signals distinctive to Belatacept
- Cytomegalovirus infection — n=180, PRR 49.3 Labeled adverse reaction
- Acute kidney injury — n=178, PRR 5.3 Labeled (related wording)
- Leukopenia — n=82, PRR 7.4 Labeled adverse reaction
- Respiratory failure — n=77, PRR 4.8 Labeled (related wording)
- Renal tubular necrosis — n=36, PRR 16.6 Labeled adverse reaction
- Nephropathy toxic — n=36, PRR 14.6 Labeled (related wording)
- Proteinuria — n=32, PRR 7.7 Labeled adverse reaction
- Acute respiratory distress syndrome — n=27, PRR 6.9 Labeled (related wording)
Common questions
Which has more reported side effects, Abatacept or Belatacept?
Abatacept has 137,367 FAERS reports and Belatacept 4,646. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (60% vs 76%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Abatacept and Belatacept share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Abatacept or Belatacept safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.