Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Anti-PD-1 monoclonal antibody (immune checkpoint inhibitor)

Pembrolizumab

Brand names: Keytruda

Pembrolizumab is an anti-PD-1 immune checkpoint inhibitor monoclonal antibody given by intravenous infusion, used in oncology across many tumour types; it is relevant to rheumatology mainly because it can trigger immune-related inflammatory conditions.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It blocks the PD-1 receptor on T cells, preventing engagement by PD-L1/PD-L2 and thereby releasing the brakes on T-cell-mediated anti-tumour immune responses.

Prescribing in practice

  • Immune-related adverse events can affect almost any organ — including colitis, pneumonitis, hepatitis, endocrinopathies, nephritis and inflammatory arthritis — and may be severe or fatal, so recognise early and manage promptly, usually with corticosteroids and treatment interruption per the SPC.
  • Endocrinopathies such as thyroid dysfunction, hypophysitis and adrenal insufficiency are common and may be permanent, requiring hormone replacement.
  • Severe infusion reactions can occur and warrant interruption or discontinuation.

Monitoring

Monitor thyroid, liver, renal and glucose parameters and review for new symptoms in any organ system at each cycle so that immune-related toxicities are caught and treated early.

Counselling the patient

  • Report any new diarrhoea, breathlessness, rash or severe fatigue promptly.
  • Tell any clinician you are on immunotherapy, even after stopping.
  • Joint pain or swelling can occur and should be reviewed.

Evidence & guidelines

Its broad oncology indications are supported by numerous randomised trials demonstrating improved survival across multiple cancers.

Reference: multiple NICE TAs; ESMO Immuno-oncology toxicity guidelines; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways