Anti-PD-1 monoclonal antibody (specialist) Pregnancy: Not recommended during pregnancy or in women of childbearing potential not using effective contraception unless clinical benefit outweighs risk. Human IgG4 crosses the placenta; PD-1/PD-L1 inhibition may increase risk of immune-mediated foetal rejection/foetal death. Women of childbearing potential should use effective contraception during and for at least 4 months after the last dose. Do not breast-feed during and for at least 4 months after the last dose.

Cemiplimab

Brand names: Libtayo

Cemiplimab is a monoclonal antibody immune checkpoint inhibitor, given by intravenous infusion, used for advanced cutaneous squamous cell carcinoma, basal cell carcinoma and non-small-cell lung cancer.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 350 mg

Route: intravenous infusion over 30 minutes

Frequency: every 3 weeks (Q3W)

Treatment must be initiated and supervised by physicians experienced in cancer treatment. Locally advanced or metastatic CSCC, NSCLC, BCC and recurrent/metastatic cervical cancer: 350 mg every 3 weeks until disease progression or unacceptable toxicity. Adjuvant treatment of high-risk CSCC: either 350 mg every 3 weeks for 12 weeks followed by 700 mg every 6 weeks, or 350 mg every 3 weeks; continue until disease recurrence, unacceptable toxicity, or up to 48 weeks total therapy. No dose reductions recommended; dosing delay or permanent discontinuation may be required for immune-mediated adverse reactions (see SPC Table 1). NSCLC patients should be evaluated for PD-L1 tumour expression by a validated test.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients

Side effects

Immune-mediated hypothyroidism
Immune-mediated hyperthyroidism
Immune-mediated pneumonitis
Immune-mediated hepatitis
Immune-mediated colitis and immune-mediated skin adverse reactions (incl. SJS/TEN)

Clinical monograph

How it works

It binds the programmed cell death protein 1 (PD-1) receptor on T cells, blocking its interaction with PD-L1 and PD-L2 and restoring anti-tumour immune responses.

Prescribing in practice

It can cause serious immune-related adverse effects affecting any organ (including the lungs, bowel, liver and endocrine glands), which may require corticosteroids and treatment interruption.
Infusion-related reactions can occur and should be monitored for during administration.
Be alert to endocrinopathies, which can present non-specifically and may need long-term hormone replacement.

Monitoring

Monitor liver, renal, thyroid and other endocrine function and watch for symptoms of immune-related toxicity before and during treatment.

Counselling the patient

Report new or worsening symptoms such as persistent diarrhoea, breathlessness, rash, or unusual tiredness promptly, as these may be immune-related.
Carry your immunotherapy alert card and show it to any healthcare professional treating you.
Tell the team about symptoms even after treatment ends, as effects can be delayed.

Evidence & guidelines

NICE has appraised cemiplimab for advanced cutaneous squamous cell carcinoma and other indications, supported by clinical trial evidence.

Reference: NICE TA592; NICE TA770; ESMO; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Dostarlimab · Anti-PD-1 monoclonal antibody (specialist)

Pathways