Pembrolizumab (Head and Neck SCC)
Brand names: Keytruda
Pembrolizumab is an intravenous immune-checkpoint inhibitor used in recurrent or metastatic squamous cell carcinoma of the head and neck, including as first-line therapy (alone or with chemotherapy) in tumours expressing PD-L1.
Adult dose
Dose adjustments
No dose adjustment is needed for patients with mild or moderate renal impairment; KEYTRUDA has not been studied in patients with severe renal impairment (§4.2).
Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. 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
- Fatigue (31% with monotherapy)
- Diarrhoea (22% with monotherapy)
- Nausea (20% with monotherapy)
- Immune-mediated adverse reactions - the most serious reactions; 37% all grades / 9% Grades 3-5 in the adjuvant setting and 25% all grades / 6% Grades 3-5 in the metastatic setting (includes pneumonitis, colitis, nephritis, endocrinopathies)
- Severe infusion-related reactions
- In combination with chemotherapy/radiation/chemoradiotherapy: anaemia (51%), nausea (50%), fatigue (36%), diarrhoea (35%), constipation (32%), vomiting (27%), decreased appetite (26%); Grades 3-5 reactions in 80% of HNSCC patients on combination therapy
Clinical monograph
How it works
Pembrolizumab is a monoclonal antibody against the programmed death-1 (PD-1) receptor; by blocking PD-1 binding to PD-L1 and PD-L2 it releases inhibition of tumour-specific T cells and enhances antitumour immunity.
Prescribing in practice
- Immune-related adverse events can affect any organ system — pneumonitis, colitis, hepatitis, endocrinopathies, nephritis and severe skin reactions — and may be serious or delayed, demanding early recognition and corticosteroid/immunosuppressive treatment.
- Eligibility and combination choice depend on PD-L1 expression testing, and infusion-related reactions can occur.
- Treatment must be initiated and supervised by oncologists experienced in immunotherapy, with endocrinopathies often requiring hormone replacement rather than stopping the drug alone.
Monitoring
Check liver, thyroid, renal function and glucose before dosing and investigate new respiratory, gastrointestinal, endocrine, renal or skin symptoms promptly as possible immune-related toxicity.
Counselling the patient
- Report new or worsening symptoms quickly — breathlessness, persistent diarrhoea, jaundice, extreme fatigue or rash — as the treatment can make your immune system attack healthy organs.
- Carry your immunotherapy alert card and show it to every healthcare professional.
- Reactions can develop weeks or months later, so continue reporting symptoms even after treatment ends.
Evidence & guidelines
Pembrolizumab is licensed in recurrent/metastatic head and neck SCC on the basis of randomised trials (including KEYNOTE-048) showing improved survival, with NICE positioning informed by PD-L1 expression.
Reference: KEYNOTE-048 (Burtness et al. NEJM 2019); NICE TA670; MHRA SPC Keytruda; ESMO HNSCC Guidelines (2021); 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).
Related
Curated clinical cross-links plus same-class fallbacks.
- SMART2 Risk Score for Recurrent Vascular Events · Cardiovascular Risk
- PCSK9 Inhibitor Eligibility (NICE TA393 / TA394) · Lipid Management
- Glasgow Coma Scale · Neurological
- CT Head Rules — Adults (NICE NG232) · Head Injury
- HINTS Plus (Central vs Peripheral Vertigo) · Vertigo / Dizziness
- Immune-Related Adverse Events (irAE) -- GI Toxicity Colitis Grading · Oncology-Related GI
- Adult Upper Airway Obstruction (Stridor) · DAS 2015 unanticipated difficult airway; RCEM
- Epistaxis Management · ENT-UK / NICE
- Acute Otitis Media · NICE NG91 2018
- Tonsillitis and Sore Throat · NICE NG84 2018
- Benign Paroxysmal Positional Vertigo · NICE CG124 / AAO-HNS Guidelines
- Acute Rhinosinusitis · NICE NG79 2017 / EPOS 2020