Retifanlimab
Retifanlimab is an immunotherapy medication that belongs to a class of drugs called checkpoint inhibitors. It works by blocking the PD-1 receptor on T cells, allowing the immune system to better recognize and attack cancer cells. This medication is used to treat adults with metastatic or recurrent locally advanced Merkel cell carcinoma, a rare and aggressive form of skin cancer.
Retifanlimab is a PD-1 inhibitor immunotherapy used to treat certain cancers by helping the immune system attack tumor cells.
Key facts at a glance
- ATC
- L01FF10
- RxNorm
- 2632981
- Generic
- Retifanlimab
- Class
- atc-l01
- Brands
- Zynyz
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg
- Maximum
- consult physician
- Frequency
- every 4 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- Not established
- Maximum
- consult physician
- Frequency
- N/A
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 500mg
- Maximum
- consult physician
- Frequency
- every 4 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks; discuss potential fetal harm with patients of reproductive potential
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second third trimesteravoid
discontinue treatment if pregnancy occurs; advise women to avoid becoming pregnant during treatment
fetal ultrasounds as clinically indicated
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingdiscontinue
do not breastfeed during treatment and for at least 4 months after last dose
none established
geriatric
elderly 65no specific adjustment
use with caution; monitor for adverse reactions; no overall differences in efficacy observed but increased susceptibility to immune-mediated adverse reactions
regular monitoring for immune-mediated adverse events
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsnot established
safety and efficacy not established in pediatric patients; use only in clinical trials when specifically indicated
not established
renal_impairment
mild moderateno dose adjustment
no dose adjustment needed for mild to moderate renal impairment; monitor renal function
regular renal function monitoring
Use with caution and monitor for adverse effects.
renal_impairment
severeuse with caution
limited data in severe renal impairment; use only if benefits outweigh risks
close renal function monitoring
Use with caution and monitor for adverse effects.
hepatic_impairment
mild moderateno dose adjustment
no dose adjustment needed for mild to moderate hepatic impairment; monitor liver function
regular liver function tests
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Immunotherapy class information
FDA approval year
FDA approval for Zynyz (Retifanlimab)
Common uses
Indicated for the treatment of adults with metastatic or recurrent locally advanced Merkel cell carcinoma
Mechanism of action
Binds to PD-1 receptor and blocks its interaction with PD-L1 and PD-L2
Retifanlimab is approved for the treatment of adults with metastatic or recurrent locally advanced Merkel cell carcinoma (MCC). It is used when the cancer has spread or returned after prior treatment.
Retifanlimab is a monoclonal antibody that binds to the PD-1 receptor on T cells, blocking interaction with PD-L1 and PD-L2 ligands. This prevents tumor cells from using the PD-1 pathway to suppress immune responses, restoring T-cell function to recognize and destroy cancer cells.
Common side effects may include fatigue, rash, fever, and immune-related adverse reactions affecting various organs. Patients should be monitored for immune-mediated side effects, which may require treatment interruption or corticosteroids. Use during pregnancy is not recommended.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy