Gemtuzumab ozogamicin (Specialist drug)

How it works

Its anti-CD33 antibody binds leukaemic blasts and, on internalisation, releases the DNA-damaging calicheamicin derivative that causes double-strand breaks and apoptosis.

Prescribing in practice

• Hepatotoxicity, including potentially fatal veno-occlusive disease (sinusoidal obstruction syndrome), is a key risk and requires close monitoring of liver function and clinical vigilance, particularly around stem-cell transplant.
• Severe and sometimes fatal infusion reactions can occur, so give premedication and administer under supervision with the infusion slowed or stopped if reactions develop.
• Profound myelosuppression and tumour lysis syndrome can occur; ensure supportive care and blood-count monitoring.

Monitoring

Monitor liver function tests (watching for veno-occlusive disease), full blood count, and for infusion reactions and tumour lysis around each dose.

Counselling the patient

• Report any fever, chills, breathlessness or rash during or after the infusion.
• Tell your team about abdominal pain, swelling or yellowing of the skin or eyes.
• Attend all blood tests, as your counts and liver will be monitored closely.

Evidence & guidelines

Gemtuzumab ozogamicin is licensed for CD33-positive acute myeloid leukaemia on the basis of randomised trial data, with its veno-occlusive disease risk well characterised in the SPC and haematology literature.