Panitumumab (Specialist drug)

How it works

It is a fully human monoclonal antibody that binds the epidermal growth factor receptor (EGFR), blocking ligand binding and downstream signalling that drives tumour cell growth.

Prescribing in practice

• It is only effective in tumours with wild-type RAS and may be harmful in RAS-mutant tumours, so RAS mutation status must be confirmed before treatment.
• Severe skin reactions, including a characteristic acneiform rash, are very common and can become infected.
• Infusion reactions and electrolyte disturbances such as hypomagnesaemia can occur and require monitoring.

Monitoring

Monitor serum magnesium and other electrolytes during and after treatment and assess skin for reactions.

Counselling the patient

• Use sun protection and emollients as advised, and report worsening or infected skin rash.
• Report any breathlessness or reaction during the infusion.

Evidence & guidelines

Use is restricted to RAS wild-type metastatic colorectal cancer in line with NICE guidance and registration trials.