Cemiplimab is a programmed death receptor-1 (PD-1) blocking antibody indicated for the treatment of patients with metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or curative radiation therapy. As an immunotherapeutic agent, its use must strictly adhere to dosage regimens, and medication strategies should be adjusted based on individual patient conditions.

How to Administer Cemiplimab

Recommended Dosage Regimen

The standard recommended dose of cemiplimab is 350 mg, administered via intravenous infusion. Each infusion must last 30 minutes, with an administration frequency of once every 3 weeks.

This dosage regimen is applicable to most adult patients. Treatment should continue until disease progression or the occurrence of unacceptable toxicity.

Precautions for Drug Preparation

Before use, visually inspect the drug solution for particulate matter and discoloration.

Cemiplimab should appear as a clear to slightly opalescent, colorless to pale yellow solution.

If the solution is cloudy, discolored, or contains foreign matter (other than trace amounts of translucent to white particles), discard the vial.

Withdraw 7 mL of the drug solution and dilute it with 0.9% Sodium Chloride Injection or 5% Dextrose Injection to a final concentration of 1–20 mg/mL.

Mix the diluted solution by gentle inversion; do not shake.

Precautions for Administration

At room temperature (not exceeding 25°C/77°F), the time from completion of preparation to the end of infusion must not exceed 8 hours.

At 2°C to 8°C (36°F to 46°F), the time from completion of preparation to the end of infusion must not exceed 24 hours.

Allow the diluted solution to return to room temperature before use.

Freezing is strictly prohibited.

Key Notes for Actual Administration

Administer via an intravenous line equipped with a sterile in-line or add-on filter (pore size: 0.2 to 5 micrometers).

Strictly control the infusion time to 30 minutes.

Discard any unused medication or waste materials in accordance with relevant regulations.

Dose Adjustment of Cemiplimab

Dose Adjustment for Immune-Mediated Adverse Reactions

Immune-Mediated Pneumonitis:

Grade 2: Withhold administration.

Grade 3 or 4: Discontinue administration permanently.

Immune-Mediated Colitis:

Grade 2 or 3: Withhold administration.

Grade 4: Discontinue administration permanently.

Immune-Mediated Hepatitis:

If AST/ALT elevates to 3–10 times the upper limit of normal (ULN), or total bilirubin elevates to 3 times ULN: Withhold administration.

If AST/ALT elevates to more than 10 times ULN, or total bilirubin elevates to more than 3 times ULN: Discontinue administration permanently.

Dose Adjustment for Infusion Reactions

Grade 1 or 2: Interrupt the infusion or slow down the infusion rate.

Grade 3 or 4: Discontinue administration permanently.

Use of Cemiplimab in Special Populations

Pregnant Women

Cemiplimab may cause fetal harm. Animal studies have shown that inhibition of the PD-1/PD-L1 pathway increases the risk of immune-mediated fetal rejection, which may lead to fetal death.

Recommendations: Confirm the pregnancy status of women with reproductive potential before initiating treatment.

Advise women to use effective contraceptive measures during treatment and for at least 4 months after the last dose.

If the drug is used during pregnancy, or if a patient becomes pregnant while receiving treatment, inform the patient of the potential risk to the fetus.

Lactating Women

There are no data on whether cemiplimab is present in human milk. However, due to the potential for severe adverse reactions in breastfed infants:

Recommendation: Do not breastfeed during treatment and for at least 4 months after the last dose.

Patients with Hepatic or Renal Impairment

Patients with mild to severe renal impairment (creatinine clearance: 25–420 mL/min): No dose adjustment is required.

Patients with mild hepatic impairment (total bilirubin: 0.35–45 μmol/L): No dose adjustment is required.

Patients with moderate or severe hepatic impairment: No clinical studies have been conducted; use with caution.