Pembrolizumab (Keytruda, Merck Sharp & Dohme) is a humanised monoclonal antibody that acts on the 'programmed death 1' protein (PD‑1). The PD‑1 protein is part of the immune checkpoint pathway, and blocking its activity may promote an anti-tumour immune response.
Pembrolizumab has a marketing authorisation for treating locally advanced or metastatic non‑small‑cell lung cancer (NSCLC) in adults whose tumours express PD‑L1 (that is, with a tumour proportion score [TPS] ≥1%) and who have had at least 1 chemotherapy regimen. Patients with epidermal growth factor receptor (EGFR)- or anaplastic lymphoma kinase (ALK)‑positive tumour mutations should also have had approved therapy for these mutations before having pembrolizumab.
The most common treatment-related adverse events associated with pembrolizumab include fatigue, decreased appetite, nausea, rash and pruritus. For full details of adverse reactions and contraindications, see the summary of product characteristics.
2 mg/kg every 3 weeks by intravenous (IV) infusion. The summary of product characteristics recommends treatment with pembrolizumab until disease progression or unacceptable toxicity.