As an immune checkpoint inhibitor, Cemiplimab has shown significant efficacy in the treatment of malignant tumors such as cutaneous squamous cell carcinoma. However, its use may also be accompanied by a series of immune-related side effects.

Side Effects of Cemiplimab

1. Common Immune-Mediated Adverse Reactions

(1) According to clinical trial data, fatigue (29%), rash (25%), and diarrhea (22%) are the most common side effects.

(2) Other reactions include immune-mediated pneumonia (2.4%), hepatitis (2.1%), and colitis (0.9%). Some of these may be life-threatening; for example, the incidence of Grade 5 pneumonia is 0.2%.

2. Effects on Other Organ Systems

(1) Endocrine disorders such as thyroid dysfunction (6% hypothyroxinemia, 1.5% hyperthyroxinemia) and type 1 diabetes mellitus (0.7%) have also been reported.

(2) The incidence of skin reactions such as erythema multiforme and pemphigoid is 1.7%. Although neurological and cardiovascular events are rare, they require vigilance.

Methods to Alleviate the Side Effects of Cemiplimab

1. Dosage Adjustment and Treatment Interruption

(1) Depending on the grade of adverse reactions, it is recommended to interrupt or permanently discontinue the treatment. For instance, administration should be withheld in case of Grade 2 pneumonia, and permanently discontinued in case of Grade 3 or 4 pneumonia.

(2) Similar principles apply to reactions such as hepatitis and colitis.

2. Pharmacological Treatment and Supportive Care

(1) Corticosteroids are the first choice for managing most immune reactions, such as prednisone at a dose of 1–2 mg/kg per day.

(2) For cases unresponsive to corticosteroids, additional immunosuppressants may be required.

(3) Supportive care, including antidiarrheal agents, skin moisturizers, and hormone replacement therapy, is also necessary.

(4) Through personalized management strategies, most side effects can be controlled, thereby maintaining treatment continuity and improving patients' quality of life.

Medication of Natalizumab in Special Populations

1. Pregnant and Lactating Women

(1) Based on animal data, Cemiplimab may cause fetal harm. It is recommended that women of childbearing age use effective contraception during treatment and within 4 months after the last dose.

(2) Breastfeeding should be avoided during lactation, as the drug may be excreted in breast milk.

2. Elderly Patients and Patients with Hepatic or Renal Impairment

(1) In clinical studies, 72% of patients were aged ≥65 years, and no difference in safety was observed.

(2) No dosage adjustment is required for patients with mild hepatic or renal impairment. However, data on patients with moderate to severe impairment are insufficient, and careful assessment is needed.