Canterbury DHB

Monoclonal Antibodies

Rituximab

Rituximab, a humanised anti CD20 monoclonal antibody, was approved for use overseas in indolent lymphomas in 1997. Since then, Rituximab has been used widely in all types of B-cell CD20 positive lymphomas. It has also been effective in a number of non-malignant conditions when immunosuppression combined with low toxicity is required.

• Rituximab is generally well tolerated. The first dose is most likely to produce an adverse reaction. It may produce cytokine release with severe shortness of breath, bronchospasm, hypoxia, fever, rigors, urticaria, and angioedema and can be life threatening. It should only be given where resuscitation facilities are available and senior medical staff are nearby.
• Patients with a high white cell count before rituximab therapy may require treatment to be split over 2 days. Where at all possible this should be planned allowing two separate rituximab infusions to be made.
• In the event that infusion-related reactions prevent a patient from completing their infusion, the remainder of the bag, with infusion set attached, may be stored in the fridge overnight and the infusion recommenced the next day after replacing the infusion set. Any rituximab remaining 24 hours after the start of the initial infusion must be discarded.

Alemtuzumab

Alemtuzumab, a humanised anti CD52 monoclonal antibody, is licensed as a third line treatment for B cell CLL.

Standard treatment involves a subcutaneous injection (unlicensed) or IV infusion three days a week, starting at 3 mg and progressing to 10 mg and finally 30 mg as infusion-related reactions allow. For intravenous infusions, premedication with hydrocortisone 100 mg, chlorphenamine 10mg, and paracetamol 1000 mg is recommended to minimise the infusion-related reactions. Dose escalation should not occur until the current dose is tolerated. Additionally, if treatment is delayed by more than a week, then dose titration should be restarted.

Cutaneous skin reactions are more prevalent with subcutaneous administration.

Alemtuzumab administration is currently the preferred method of T cell depletion prior to allogeneic stem cell transplant. For more information and specific dosing regimen, see the individual transplant protocol.

Alemtuzumab is only available via a compassionate use scheme. Contact the haematology pharmacist for the application paperwork and to coordinate supply.

Obinuzumab

Obinutuzumab is a humanised anti-CD20 monoclonal antibody indicated and funded for treatment of chronic lymphocytic leukaemia for patients not eligible for full dose FCR treatment. It is also indicated for, but not funded for indolent NHL.

Obinutuzumab has a high rate of immune reactions, so patients will be admitted to B6 for the administration of their first dose. This first dose of 1000 mg will be split over 2 days, with 100 mg given on day 1 and 900 mg given on day 2. Patients also receive pre-medications with methylprednisolone, loratadine and paracetamol. Subsequent infusions are usually well tolerated and are given in the Haematology Day Ward.

Topic Code: 5732