Idelalisib
ZYDELIG
What it isPI3K-delta inhibitor; relapsed CLL and follicular lymphoma.
Why this oneIt targets a signaling node specific to B cells.
What limits itSevere autoimmune toxicity — colitis, pneumonitis, hepatitis — which limited its use. A strong CYP3A4 inhibitor.
FDA-approved for
- chronic lymphocytic leukemia (2014)
- follicular lymphoma (2014)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Relapsed CLL (with rituximab); relapsed follicular lymphoma / SLL | Adults | 150 mg BID | 150 mg BID | 150 mg BID (reduce to 100 mg BID for toxicity) |
Renal Undefined
Hepatic No adjustment for ALT/AST/bilirubin > ULN; limited data with baseline AST/ALT >2.5×ULN or bilirubin >1.5×ULN — monitor
Instructions
- Swallow tablets whole; with or without food
- If dose missed <6 h, take ASAP; if >6 h, skip that dose
- Provide PJP prophylaxis; monitor for CMV
- Reduce to 100 mg BID when resuming after interruption for toxicity
Contraindications
- History of toxic epidermal necrolysis with any drug
Cautions
- Hepatotoxicity
- Severe diarrhea/colitis
- Pneumonitis
- Serious infections (incl PJP, CMV)
- Intestinal perforation
- Severe cutaneous reactions (SJS/TEN/DRESS)
- Serious hypersensitivity/anaphylaxis
- Neutropenia
- Embryo-fetal toxicity
Adverse reactions
- Diarrhea
- Pneumonia
- Pyrexia
- Fatigue
- Rash
- Cough
- Nausea
- Neutropenia and ALT/AST elevations
Pregnancy May cause fetal harm; use effective contraception during and 1 month after
Lactation Do not breastfeed during and for 1 month after last dose
⚠ BOXED WARNINGS
- Fatal hepatotoxicity
- Severe diarrhea and colitis
- Pneumonitis
- Intestinal perforation
Cost, est. cash$5,000–$30,000+/month or cycle
Generic entry2026
Classes and tags
Clinical profile
Legacy pregnancy categoryD
Defining liabilityMyelosuppression and agent-specific hepatic, cardiac, pulmonary, neurologic or reproductive toxicity require oncology monitoring.
Mechanism of action: Idelalisib ballicule
