Loncastuximab tesirine (Specialist drug)

How it works

The anti-CD19 antibody delivers a pyrrolobenzodiazepine dimer toxin into CD19-expressing B cells, where it cross-links DNA and triggers cell death.

Prescribing in practice

• It commonly causes serositis-related fluid accumulation such as pleural and pericardial effusions and oedema, which can be serious and require prompt assessment and management.
• Myelosuppression — particularly neutropenia and thrombocytopenia — is frequent, so blood counts are checked before each infusion and doses adjusted or delayed accordingly.
• Photosensitivity and skin reactions occur, and the drug is given by intravenous infusion only in a specialist setting.

Monitoring

Monitor full blood count before each cycle, together with clinical and as-needed imaging assessment for effusions, oedema and liver function.

Counselling the patient

• Tell the team about new breathlessness, swelling or chest discomfort, which may signal fluid build-up.
• Protect skin and eyes from sunlight and use high-factor sun protection during and after treatment.
• Report signs of infection, bruising or bleeding without delay.

Evidence & guidelines

Approved for relapsed/refractory diffuse large B-cell lymphoma on the basis of single-arm trial data; use within licensed and specialist commissioning arrangements.