Retifanlimab-dlwr Injection
Retifanlimab-dlwr is a PD-1–blocking immunotherapy used to treat squamous cell carcinoma of the anal canal and Merkel cell carcinoma in adults.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Retifanlimab-dlwr Injection: Patient Information Guide
A plain-language walkthrough of Retifanlimab-dlwr Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Retifanlimab-dlwr (brand name Zynyz) is an immunotherapy approved for two types of cancer in adults:
- Squamous cell carcinoma of the anal canal (SCAC) — combination therapy: Zynyz, given together with carboplatin and paclitaxel, is a first-line treatment for adults with inoperable locally recurrent or metastatic SCAC.
- Squamous cell carcinoma of the anal canal (SCAC) — single-agent therapy: Zynyz alone is used for adults with locally recurrent or metastatic SCAC whose cancer has progressed on platinum-based chemotherapy, or who cannot tolerate it.
- Merkel cell carcinoma (MCC): Zynyz is used for adults with metastatic or recurrent locally advanced Merkel cell carcinoma, a rare and aggressive type of skin cancer.
⚙️How it works▾
Cancer cells sometimes exploit a protein called PD-1 on immune T cells — essentially flipping a switch that tells your immune system to stand down and ignore them. Retifanlimab-dlwr binds to PD-1 and blocks this signal, preventing cancer cells from using this escape route. With PD-1 blocked, T cells stay active and are better able to find and destroy cancer cells.
💊How it's taken▾
Zynyz is given exclusively as an intravenous (IV) infusion by a trained healthcare professional — it is not taken by mouth. Each infusion is administered over 30 minutes. Depending on the condition being treated and the schedule your doctor has chosen, Zynyz is given either every 3 weeks or every 4 weeks.
- For SCAC (combination or single-agent), your doctor may schedule infusions every 3 or every 4 weeks.
- For Merkel cell carcinoma, Zynyz is given every 4 weeks.
- Treatment continues until the cancer progresses, side effects become unacceptable, or the maximum treatment duration is reached — always follow your care team's guidance on your specific schedule.
🤒Side effects — in detail▾
Common side effects vary depending on whether Zynyz is used alone or with chemotherapy, but frequently reported reactions include:
- Fatigue
- Nausea and vomiting
- Diarrhea
- Muscle and joint pain (musculoskeletal pain)
- Rash and itching (pruritus)
- Constipation
- Decreased appetite
- Underactive thyroid (hypothyroidism)
- Hair loss (alopecia) — particularly when used with carboplatin and paclitaxel
- Nerve tingling or numbness (peripheral neuropathy) — particularly when used with carboplatin and paclitaxel
More serious immune-related reactions can affect the lungs, liver, bowel, kidneys, skin, and hormone glands — contact your care team immediately if you notice new or worsening symptoms in any of these areas.
⚠️Warnings & precautions▾
The most critical concern with Zynyz is immune-mediated toxicity — your immune system can become overactivated and attack healthy organs. This can happen in the lungs (pneumonitis), intestines (colitis), liver (hepatitis), kidneys (nephritis), skin (severe rashes), or hormone glands (endocrinopathies). These reactions can be severe or fatal and can occur during treatment or even after it has stopped. Your care team will test your liver enzymes, kidney function, and thyroid levels regularly.
- Immune-mediated reactions in any organ system — including the heart, nerves, and eyes — require prompt medical attention; treatment may need to be paused or permanently stopped.
- Infusion reactions can occur during or right after the IV drip; nurses will monitor you closely.
- Stem cell transplant complications: Serious and sometimes fatal complications have occurred in patients who received a donor (allogeneic) stem cell transplant before or after PD-1–blocking therapy.
- Embryo-fetal toxicity: Zynyz can cause fetal harm, including miscarriage or stillbirth; it must not be used during pregnancy.
🔀What it interacts with▾
The FDA label for Zynyz does not list specific drug, food, or supplement interactions. However, since Zynyz works by activating the immune system, always tell your full care team about every medication, supplement, or herbal product you take — especially anything that affects the immune system.
- Inform your care team about any immunosuppressant medications, as these may interfere with how Zynyz works.
- If you require corticosteroids (such as prednisone) to manage a Zynyz side effect, your team will guide you on timing and tapering.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Pregnancy: Zynyz can cause serious fetal harm. A pregnancy test is required before starting, and effective contraception must be used during treatment and for 4 months after the last dose.
- Breastfeeding: Do not breastfeed during treatment or for 4 months after the last dose due to potential harm to the infant.
- Transplant history: Tell your doctor if you have had any organ transplant or allogeneic (donor) stem cell transplant — serious complications have been reported.
- Autoimmune conditions: Zynyz can worsen pre-existing autoimmune conditions or trigger new immune reactions; discuss your full medical history with your doctor.
- Children: Safety and effectiveness in pediatric patients have not been established.
- Older adults: Patients 65 and older participated in clinical trials without overall differences in safety or effectiveness compared to younger adults; your doctor will monitor you closely regardless of age.
- Liver impairment: The effects of Zynyz have not been studied in patients with moderate or severe liver impairment; inform your doctor of any liver conditions.
- HIV-positive patients: HIV status did not meaningfully affect how the drug behaves in the body based on available data, but always disclose your full health history.
📡Pharmacodynamics — effects in the body▾
The full exposure-response relationship and the time course of pharmacodynamic effects for Zynyz have not been completely characterized, meaning researchers are still studying exactly how the degree of PD-1 blockade relates to treatment outcomes and side effects in individual patients.
🔬Pharmacokinetics — how your body processes it▾
After repeated IV infusions, Zynyz reaches stable (steady-state) levels in the body in about 3 months, with approximately 1.3-fold accumulation over time. The drug has a half-life of about 19 days at steady state, meaning it stays in your system for a significant period after each dose. Factors like age, sex, body weight, race, kidney function (down to a GFR of 26 mL/min/1.73 m²), and mild liver impairment do not meaningfully change how the drug behaves — so dose adjustments for these factors are generally not needed. The drug's behavior in patients with moderate or severe liver impairment has not been studied.
📦How to store it▾
Store refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Do not freeze or shake.
📄 Written from Retifanlimab-dlwr Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Retifanlimab-dlwr Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is Zynyz and why has my doctor prescribed it for me? ▾
How will I receive Zynyz, and how long will each visit take? ▾
What side effects should I watch out for, and when should I call someone right away? ▾
Can I take Zynyz if I'm pregnant or trying to get pregnant? ▾
Will Zynyz affect my thyroid or other hormone glands? ▾
How long will I be on Zynyz, and what happens if I need to stop? ▾
Is Retifanlimab-dlwr Injection available over the counter? ▾
When was Retifanlimab-dlwr Injection first available? ▾
💬 Answers drafted from Retifanlimab-dlwr Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Retifanlimab-dlwr Injection comes
Retifanlimab-dlwr Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Zynyz is used with carboplatin and paclitaxel as first-line treatment for adults with inoperable locally recurrent or metastatic squamous cell carcinoma of the anal canal (SCAC)
- Zynyz is used alone for adults with locally recurrent or metastatic SCAC that has progressed on or cannot be tolerated with platinum-based chemotherapy
- Zynyz is used for adults with metastatic or recurrent locally advanced Merkel cell carcinoma (MCC)
- Zynyz is given as an intravenous infusion over 30 minutes after dilution, either every 3 or every 4 weeks depending on the prescribed schedule
- Zynyz must not be given as a rapid IV push or bolus injection
- Zynyz should not be mixed or administered through the same IV line as other medications
- Zynyz vials are single-use only — any unused portion must be discarded after each patient's dose
📊 Retifanlimab-dlwr Injection across the U.S. market
How Retifanlimab-dlwr Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
📈 How widely Retifanlimab-dlwr Injection is used
A general measure of how commonly Retifanlimab-dlwr Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q2 2025 – Q1 2026, summed across every form and brand of the drug.
Think of this as a proxy for how widely Retifanlimab-dlwr Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Retifanlimab-dlwr Injection prescribed? Of the 1,596 medications we measure, Retifanlimab-dlwr Injection ranks #1,557 by Medicaid prescriptions — more than 2% of them.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Retifanlimab-dlwr Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 1 of 1 listed Retifanlimab-dlwr Injection NDCs with Medicaid activity.
🔍 Compare Retifanlimab-dlwr Injection products
A representative set of FDA-listed product records for Retifanlimab-dlwr Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 25 mg/mL | Intravenous | Incyte Corporation × 3 listings | BLA | View NDC → |
Showing 3 of 3 products — FDA National Drug Code Directory. See every product, package size and price: browse all 3 Retifanlimab-dlwr Injection NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Retifanlimab-dlwr Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Retifanlimab-dlwr Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Retifanlimab-dlwr Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
📦 Supply & shortage status
Whether Retifanlimab-dlwr Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Incyte Corporation is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.