Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ZYDELIG vs COPIKTRA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Idelalisib is a selective inhibitor of phosphatidylinositol 3-kinase delta (PI3Kδ), blocking the PI3K/AKT signaling pathway, leading to reduced proliferation, survival, and migration of malignant B cells.
Selective phosphoinositide 3-kinase (PI3K) delta and gamma inhibitor. Blocks PI3K signaling, reducing proliferation and survival of malignant B cells and T cells, and inhibits chemotaxis and adhesion of these cells.
Relapsed chronic lymphocytic leukemia (CLL) in combination with rituximab,Relapsed follicular B-cell non-Hodgkin lymphoma (FL) in patients who have received at least two prior systemic therapies,Relapsed small lymphocytic lymphoma (SLL) in patients who have received at least two prior systemic therapies
Relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma after at least two prior therapies,Relapsed or refractory follicular lymphoma after at least two prior systemic therapies
150 mg orally twice daily, taken with food.
25 mg orally twice daily
Terminal elimination half-life is 6.5 hours (range 4-10 hours) after oral administration, supporting twice-daily dosing.
Terminal elimination half-life is approximately 7–10 hours in patients with relapsed or refractory CLL/SLL. Steady-state is achieved within 3–5 days of twice-daily dosing.
Primarily metabolized by aldehyde oxidase (AO) and CYP3A4, with minor contributions from UGT1A4.
Primarily metabolized by CYP3A4; also involves CYP3A5 and UDP-glucuronosyltransferases (UGTs).
Primarily hepatic metabolism, with 44% of dose excreted in feces (as metabolites) and 22% in urine (unchanged drug and metabolites).
Primarily via fecal excretion (approximately 70% of total dose) as unchanged drug and metabolites, with renal excretion accounting for <15% of the dose.
84% bound to plasma proteins, primarily to albumin and alpha-1-acid glycoprotein.
~84% bound to plasma proteins, primarily to albumin.
Mean volume of distribution is 113 L (approximately 1.4 L/kg), indicating extensive tissue distribution.
Mean apparent volume of distribution (Vz/F) is approximately 100–150 L (or ~1.4–2.1 L/kg based on typical body weight), indicating extensive tissue distribution.
Absolute oral bioavailability is 40% (range 30-50%) due to first-pass metabolism.
Oral bioavailability is approximately 22% following a 25 mg capsule under fasting conditions. Absorption is increased with high-fat meals; therefore, it should be taken on an empty stomach.
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). For severe renal impairment (Cr Cl <30 m L/min), not recommended due to lack of data.
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended in severe renal impairment (Cr Cl <30 m L/min).
Child-Pugh Class A: No dose adjustment. Child-Pugh Class B: Reduce dose to 100 mg twice daily. Child-Pugh Class C: Not recommended.
Contraindicated in severe hepatic impairment (Child-Pugh class C). For mild (Child-Pugh class A) or moderate (Child-Pugh class B), reduce dose to 25 mg once daily.
Safety and efficacy not established for patients <18 years.
Safety and efficacy in pediatric patients have not been established.
No specific dose adjustment recommended, but monitor for age-related renal and hepatic function changes.
No specific dose adjustment recommended for elderly patients, but monitor for adverse effects due to potential age-related renal or hepatic impairment.
WARNING: FATAL AND SERIOUS TOXICITIES: Hepatic, severe diarrhea/colitis, pneumonitis, and intestinal perforation. Fatal and/or serious hepatotoxicity occurred in 18% of patients. Fatal and/or serious diarrhea or colitis occurred in 14%. Fatal and/or serious pneumonitis occurred in 4%. Fatal and/or serious intestinal perforation occurred in <1%.
WARNING: FATAL AND SERIOUS TOXICITIES: Fatal and serious toxicities including infections, diarrhea or colitis, cutaneous reactions, and pneumonitis have occurred with COPIKTRA.
Hepatotoxicity: Monitor liver function tests,Severe diarrhea/colitis: Manage with supportive care and corticosteroids,Pneumonitis: Interrupt therapy and evaluate,Intestinal perforation: Discontinue if suspected,Infections: Monitor for opportunistic infections, including CMV,Neutropenia: Monitor blood counts,Embryofetal toxicity: Can cause fetal harm,Vaccinations: Avoid live vaccines during treatment
Fatal and serious infections,Fatal and serious diarrhea or colitis,Fatal and serious cutaneous reactions,Fatal and serious pneumonitis,Neutropenia,Hepatotoxicity,Embryo-fetal toxicity
History of severe hypersensitivity (e.g., anaphylaxis, Stevens-Johnson syndrome) to idelalisib or any excipient
Concurrent use with strong CYP3A inhibitors due to increased toxicity risk
Avoid grapefruit and grapefruit juice (CYP3A4 inhibition increases idelalisib exposure). Take with food to reduce nausea and diarrhea.
Avoid grapefruit and grapefruit juice; may increase dupilumab exposure. Take with or without food.
Pregnancy Category D. First trimester: Risk of fetal malformations including neural tube defects and craniofacial anomalies based on animal studies showing embryo-fetal toxicity and teratogenicity. Second and third trimesters: Risk of fetal hematologic toxicity (leukopenia, neutropenia) and potential growth restriction. Counsel women of childbearing age to use effective contraception during treatment and for 1 month after last dose.
COPIKTRA (duvelisib) is contraindicated in pregnancy. Based on its mechanism of action as a PI3K inhibitor and animal studies, it can cause fetal harm. In animal reproduction studies, duvelisib was embryotoxic and fetotoxic at maternal exposures below the recommended human dose. There are no adequate human data. Risks include embryo-fetal mortality, structural abnormalities, and growth impairment across all trimesters.
No human data on presence in breast milk; risk of serious adverse reactions in breastfed infants (immunosuppression, neutropenia). M/P ratio not determined. Advise not to breastfeed during treatment and for 1 week after last dose.
No data on duvelisib presence in human milk, effects on breastfed infant, or milk production. Due to potential for serious adverse reactions (e.g., immunosuppression, neutropenia), advise women not to breastfeed during treatment and for at least 1 month after last dose. M/P ratio unknown.
No dose adjustment studies in pregnant women. Due to increased volume of distribution and altered clearance in pregnancy, therapeutic drug monitoring is not established. Use minimum effective dose. If used during pregnancy, monitor for maternal neutropenia, infections, and adjust dose per standard ANC thresholds (hold if ANC < 500/mm³; resume at reduced dose when ANC > 1000/mm³).
No pharmacokinetic studies have been conducted in pregnant women. No dosing adjustments are recommended because duvelisib is contraindicated in pregnancy. If used inadvertently, the standard dose (25 mg twice daily) should be maintained until drug discontinuation is considered.
Monitor for hepatotoxicity (ALT/AST elevations), severe cutaneous reactions (Stevens-Johnson syndrome), and pneumonitis. Requires hepatic function monitoring every 2 weeks for first 2 months, then monthly. Contraindicated with CYP3A4 inducers or strong inhibitors due to metabolism via CYP3A4. Dose reduction needed for moderate hepatic impairment (Child-Pugh B).
Monitor for hepatotoxicity with baseline and periodic liver function tests; avoid live vaccines; consider dose reduction in patients with moderate hepatic impairment (Child-Pugh B); watch for infections due to neutropenia; contraindicated in severe hepatic impairment (Child-Pugh C).
Take with food to reduce gastrointestinal side effects.,Avoid grapefruit and grapefruit juice during treatment.,Report any signs of liver problems (jaundice, dark urine, abdominal pain) or skin reactions (rash, blisters) immediately.,Use effective contraception during and for at least 1 month after treatment.,Do not stop or change dose without consulting your healthcare provider.
Take exactly as prescribed; do not change dose without consulting your doctor.,Avoid grapefruit and grapefruit juice during treatment.,Report any signs of infection (fever, chills, cough) or jaundice (yellowing skin/eyes) immediately.,Use effective contraception during treatment and for at least 1 month after the last dose.,Do not receive live vaccines during or shortly after treatment.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ZYDELIG vs COPIKTRA, answered by our medical review team.
ZYDELIG is a PI3K Inhibitor Antineoplastic that works by Idelalisib is a selective inhibitor of phosphatidylinositol 3-kinase delta (PI3Kδ), blocking the PI3K/AKT signaling pathway, leading to reduced proliferation, survival, and migration of malignant B cells.. COPIKTRA is a PI3K Inhibitor Antineoplastic that works by Selective phosphoinositide 3-kinase (PI3K) delta and gamma inhibitor. Blocks PI3K signaling, reducing proliferation and survival of malignant B cells and T cells, and inhibits chemotaxis and adhesion of these cells.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ZYDELIG and COPIKTRA depend on the specific clinical indication. These are both PI3K Inhibitor Antineoplastic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ZYDELIG is: 150 mg orally twice daily, taken with food.. The standard adult dose of COPIKTRA is: 25 mg orally twice daily. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ZYDELIG and COPIKTRA in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ZYDELIG is classified as Category C. Pregnancy Category D. First trimester: Risk of fetal malformations including neural tube defects and craniofacial anomalies based on animal studies showing embryo-fetal toxicity an. COPIKTRA is classified as Category C. COPIKTRA (duvelisib) is contraindicated in pregnancy. Based on its mechanism of action as a PI3K inhibitor and animal studies, it can cause fetal harm. In animal reproduction studi. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.