DrugAlternative line2 diseases
Ibrutinib
BTK inhibitor
- Response rate
- Complete in case reports
- Onset
- 2 weeks – 3 months
- Route
- Oral 420mg daily
- Line
- Alternative
- IgM effect
- Reduces IgM
- Evidence level
- default
- Trial phase
- Phase 4
- Open Targets score
- 0.35
Used across diseases
| Disease | Response rate | Line | Evidence |
|---|---|---|---|
| Schnitzler Syndrome | Complete in case reports | Alternative | default |
| Waldenström's Macroglobulinemia | 90% ORR; 73% MRR (previously treated) | 1st | green |
Evidence summary
The only drug shown to reduce both inflammatory symptoms AND IgM levels. Three case reports (2018–2022) demonstrate efficacy, including one MYD88 L265P-positive patient where IgMκ monoclonal protein declined — unique among all treatments.
Approved indications
Conditions for which Ibrutinib has regulatory approval (not specific to rare diseases covered here):
CLL/SLLMantle Cell LymphomaWaldenström's MacroglobulinemiacGVHD
Drug identifiers
| DrugBank | DB09053 ↗ |
| ATC Code | L01EL01 |
| Open Targets | CHEMBL1873475 ↗ |
Molecular targets
| Molecule | Role | Expression | Evidence |
|---|---|---|---|
| MYD88 | TLR signalling adaptor | L265P in ~30% | moderate |
| BTK | B-cell receptor kinase | Active | moderate |
| IgM (monoclonal) | Diagnostic paraprotein | Present (obligate) | established |