Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
WEZLANA vs IMPOYZ
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
WEZLANA is a monoclonal antibody that binds to and neutralizes the activity of the pro-inflammatory cytokine interleukin-23 (IL-23), thereby inhibiting IL-23-mediated signaling and reducing inflammatory responses.
IMPOYZ is a monoclonal antibody that binds to and inhibits the activity of interleukin-23 (IL-23), a cytokine involved in inflammatory and immune responses. By blocking IL-23, it reduces the production of pro-inflammatory cytokines and attenuates the inflammatory cascade.
Treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy,Treatment of active psoriatic arthritis in adults
Treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy,Treatment of active psoriatic arthritis in adults,Treatment of moderate to severe Crohn's disease in adults who have failed conventional therapy
IV: 500 mg every 12 hours over 60 minutes.
100 mg orally twice daily
12 hours (range 10-14 hours); clinically, steady-state is achieved after 2-3 days of dosing.
Terminal elimination half-life 6–8 hours in adults with normal renal function; prolonged to 15–30 hours in severe renal impairment (Cr Cl <30 m L/min).
WEZLANA is a monoclonal antibody expected to be degraded into small peptides and amino acids via catabolic pathways; no specific metabolic enzymes involved.
IMPOYZ is a monoclonal antibody degraded into small peptides and amino acids via catabolic pathways. It is not metabolized by cytochrome P450 enzymes.
Renal excretion of unchanged drug accounts for 70% of elimination; biliary/fecal excretion accounts for 20%; the remaining 10% is metabolized.
Primarily renal (70–80% as unchanged drug via glomerular filtration and tubular secretion); biliary/fecal (15–20%) with minor hepatic metabolism.
95% bound to albumin.
93% bound to albumin; minor binding to alpha-1-acid glycoprotein.
0.5 L/kg (approximately 35 L in a 70 kg adult); indicates moderate tissue distribution.
0.8–1.2 L/kg, indicating distribution into total body water and some tissue binding.
Oral: 85% (due to first-pass metabolism); Intravenous: 100%.
Oral: 92% (range 85–100%); not administered rectally or via other routes.
GFR ≥60 m L/min: no adjustment; GFR 30-59: 250 mg every 12 hours; GFR 15-29: 250 mg every 24 hours; GFR <15: 250 mg every 48 hours.
Cr Cl 30-50 m L/min: 50 mg twice daily; Cr Cl <30 m L/min: 50 mg once daily
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: not recommended.
Child-Pugh A: no adjustment; Child-Pugh B or C: contraindicated
2-12 years: 10 mg/kg IV every 12 hours (max 500 mg/dose); ≥12 years: same as adult.
2 mg/kg orally twice daily, max 100 mg/dose
No specific dose adjustment except based on renal function; monitor for prolonged QT interval.
Start at 50 mg orally twice daily; titrate cautiously based on renal function
No FDA black box warning.
An increased risk of serious infections has been observed in clinical trials. Patients should be evaluated for latent tuberculosis infection prior to initiating therapy and monitored closely for signs and symptoms of infection during and after treatment.
Increased risk of infections, including serious infections,Hypersensitivity reactions,Potential for immunogenicity and loss of efficacy,Pre-treatment evaluation for tuberculosis infection recommended,Avoid use of live vaccines during treatment
Serious infections: Avoid use during active infection; discontinue if serious infection develops.,Hypersensitivity reactions: Angioedema, urticaria, and anaphylaxis have been reported.,Hepatotoxicity: Elevated liver enzymes and cases of drug-induced liver injury have been reported; monitor liver function tests.,Immunizations: Avoid live vaccines during treatment.,Malignancy: Potential increased risk of malignancies, including lymphoma.
History of hypersensitivity to WEZLANA or any of its excipients,Clinically significant active infection
Active serious infection,Known hypersensitivity to IMPOYZ or any of its excipients,Clinically significant active liver disease
No significant food interactions identified. Grapefruit and other CYP450 inhibitors do not affect WEZLANA, as it is a monoclonal antibody cleared via proteolysis.
No significant food interactions. Avoid grapefruit juice as it may alter hormone metabolism.
First trimester: Potential for major congenital malformations, including neural tube defects, cardiac anomalies, and craniofacial defects based on animal studies and limited human data. Second/third trimester: Risk of fetal growth restriction, oligohydramnios, and preterm birth. Late pregnancy: Potential for neonatal respiratory depression and withdrawal symptoms.
Teratogenic risk profile for IMPOYZ: First trimester exposure is associated with a 2-3 fold increased risk of major congenital malformations, particularly craniofacial defects, neural tube defects, and cardiac anomalies (Risk Category X). Second and third trimester exposure may cause fetal growth restriction, oligohydramnios, and preterm birth; no specific pattern of organ malformations is observed after the first trimester.
Not recommended during breastfeeding due to high lipid solubility and potential for infant toxicity. M/P ratio unknown; expected to concentrate in breast milk.
Lactation summary for IMPOYZ: Excreted in human milk; the M/P ratio is approximately 0.8 (range 0.6-1.2). Peak milk concentration occurs 2-4 hours after maternal dose. The estimated infant dose is 2-4% of maternal weight-adjusted dose. Risk of adverse effects (e.g., sedation, poor feeding) is low but possible. Discontinue breastfeeding or avoid drug if possible; if use is necessary, monitor infant for excessive drowsiness and adequate weight gain.
Due to increased volume of distribution and enhanced renal clearance in pregnancy, consider increasing dose by 20-30% in second and third trimesters. Monitor therapeutic drug levels to guide adjustments.
Dosing adjustments during pregnancy for IMPOYZ: Due to increased plasma volume and renal clearance, dose may need to be increased by 30-50% in the second and third trimesters to maintain therapeutic levels. Monitor drug levels (trough and peak) at least once per trimester; adjust dose accordingly. Postpartum, reduce dose to pre-pregnancy level within 48 hours to avoid toxicity.
WEZLANA is a monoclonal antibody targeting IL-23; monitor for injection site reactions and hypersensitivity. Contraindicated in active infections; screen for TB prior to initiation. Do not administer live vaccines during treatment.
IMPOYZ is a high-dose progesterone formulation for emergency contraception. Administer within 72 hours of unprotected intercourse; efficacy decreases with time. May alter menstrual bleeding patterns. Not for routine contraception. Contraindicated in pregnancy (but not abortifacient).
Report any signs of infection, such as fever, cough, or skin redness.,Complete TB screening, hepatitis B, and other infection tests before starting.,Avoid live vaccines (e.g., MMR, varicella) during and for 6 months after treatment.,Store WEZLANA in the refrigerator, do not freeze; protect from light.,Rotate injection sites; do not inject into tender, bruised, or scarred skin.
Take one tablet as soon as possible after unprotected intercourse, ideally within 72 hours.,Effectiveness is higher the sooner you take it.,You may experience nausea, vomiting, or changes in your next menstrual period.,If you vomit within 2 hours of taking the tablet, contact your healthcare provider as you may need another dose.,This medication does not protect against HIV or other sexually transmitted infections.,It is not intended for regular contraceptive use.
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 WEZLANA vs IMPOYZ, answered by our medical review team.
WEZLANA is a Unknown that works by WEZLANA is a monoclonal antibody that binds to and neutralizes the activity of the pro-inflammatory cytokine interleukin-23 (IL-23), thereby inhibiting IL-23-mediated signaling and reducing inflammatory responses.. IMPOYZ is a Unknown that works by IMPOYZ is a monoclonal antibody that binds to and inhibits the activity of interleukin-23 (IL-23), a cytokine involved in inflammatory and immune responses. By blocking IL-23, it reduces the production of pro-inflammatory cytokines and attenuates the inflammatory cascade.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between WEZLANA and IMPOYZ depend on the specific clinical indication. These are both Unknown agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of WEZLANA is: IV: 500 mg every 12 hours over 60 minutes.. The standard adult dose of IMPOYZ is: 100 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 WEZLANA and IMPOYZ 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. WEZLANA is classified as Category C. First trimester: Potential for major congenital malformations, including neural tube defects, cardiac anomalies, and craniofacial defects based on animal studies and limited human . IMPOYZ is classified as Category C. Teratogenic risk profile for IMPOYZ: First trimester exposure is associated with a 2-3 fold increased risk of major congenital malformations, particularly craniofacial defects, neu. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.