Cemiplimab (trade name: LIBTAYO) is an innovative immunotherapeutic drug that activates the human immune system to fight tumors by targeting the PD-1 pathway.

I. Indications for Cemiplimab

1. Cutaneous Squamous Cell Carcinoma (CSCC)

It is indicated for the treatment of patients with metastatic cutaneous squamous cell carcinoma (mCSCC) or locally advanced cutaneous squamous cell carcinoma (laCSCC) who are not suitable for curative surgery or curative radiotherapy.

2. Basal Cell Carcinoma (BCC)

It is indicated for the treatment of patients with locally advanced or metastatic basal cell carcinoma (laBCC or mBCC) who have previously received hedgehog pathway inhibitor therapy or are not suitable for hedgehog pathway inhibitor use.

3. Non-Small Cell Lung Cancer (NSCLC)

In combination with platinum-based chemotherapy, it is used as first-line treatment for adult patients with locally advanced (not suitable for surgical resection or curative chemoradiotherapy) or metastatic non-small cell lung cancer without EGFR, ALK, or ROS1 abnormalities.

As monotherapy, it is used as first-line treatment for adult patients with locally advanced (not suitable for surgical resection or curative chemoradiotherapy) or metastatic non-small cell lung cancer whose tumors have high PD-L1 expression [Tumor Proportion Score (TPS) ≥ 50%, confirmed by FDA-approved testing] and without EGFR, ALK, or ROS1 abnormalities.

II. Pharmacological Mechanism of Action

1. PD-1 Pathway Blockade

As an IgG4 monoclonal antibody, cemiplimab binds to the PD-1 receptor, relieves the inhibitory effect of PD-1 on T cells, and restores the immune system's ability to recognize and attack tumors.

2. Immune Response Activation

Preclinical studies have confirmed that this mechanism can reduce tumor volume in mouse models. Human pharmacokinetic data show that intravenous infusion of 350 mg every 3 weeks can achieve a stable blood drug concentration, with a half-life of approximately 19 days.

3. Cross-Organ Effects

The drug may trigger systemic immune responses, so potential effects on organs such as the lungs, liver, and endocrine glands need to be vigilantly monitored.

III. Recommendations for Patients' Healthy Lifestyle

1. Monitoring During Treatment

(1) Conduct regular examinations of liver function, thyroid function, and blood routine to detect immune-related adverse reactions (such as hepatitis, hyperthyroidism/hypothyroidism) at an early stage.

(2) Seek medical attention immediately if symptoms such as cough, diarrhea, or rash occur to avoid delaying the management of severe conditions (such as pneumonia, colitis).

2. Daily Protection

(1) Infection Prevention: Avoid contact with infection sources; consult a doctor before receiving inactivated vaccines (live vaccines are contraindicated).

(2) Skin Care: Use mild cleansing products and take sun protection measures to reduce the risk of photosensitivity reactions.

3. Management of Special Populations

(1) Pregnant Women: Strict contraception is required during treatment and within 4 months after drug discontinuation, as the drug may cause fetal immune rejection.

(2) Lactating Women: Breastfeeding is prohibited until 4 months after the last dose.