Epoetin alfa (Eprex®, Janssen-Cilag) is indicated for the treatment of anaemia associated with chronic renal failure (CRF), cancer chemotherapy, autologous blood donation and during major elective orthopaedic surgery.

Pure red cell aplasia (erythroblastopenia) has been reported in CRF patients between 1 - 92 months from the initiation of Eprex® therapy (median onset was 11 months).

From 1998 through April 2002, there have been 124 such cases of suspected pure red cell aplasia reported worldwide of which 104 are reported to have been confirmed by bone marrow examination. Antibodies to erythropoietin have been observed in 63 (out of 79 for whom results were available) Eprex® treated patients diagnosed with PRCA. Most of the worldwide reports of PRCA are associated with the subcutaneous (SC) route of administration, the predominant route of administration practiced in most countries. The estimated worldwide Eprex® exposure is 16 x 10 5 patient-years, giving a worldwide reporting incidence rate for suspected PRCA of 7.5 per 100,000 patient-years.

Based on the company's investigations, no single trigger has been identified and a number of factors may have contributed to the development of immunogenicity. Eprex® is approved to be administered by subcutaneous and intravenous injection. Available scientific information suggests that the subcutaneous route of administration for some medicines, such as Eprex®, may increase the likelihood of the body producing antibodies that could reduce the effectiveness of the medicine and possibly lead to events such as PRCA. Whilst the company continues with its investigations, Janssen-Cilag is recommending that the product be administered by the IV route in CRF patients, where feasible.

The company advises that in patients with worsening anaemia, other causes (e.g. iron, folate or vitamin B12 deficiency; aluminium intoxifcation; infection or inflammation; blood loss or haemodialysis) should be excluded. If PRCA is suspected it should be confirmed with bone marrow examination and/or antibody testing. Epoetin alfa should be discontinued, and patients should not be switched to another erythropoietin. PRCA may respond to immunosuppressive therapy and spontaneous resolution has occurred occasionally. In many of the cases, the patients become transfusion dependent.

HSA is aware of several local cases of PRCA associated with Eprex® usage, however the causality to Eprex® has not been established as yet. Healthcare professionals are encouraged to report the ADRs to Pharmacovigilance (PV) Unit should they come across any such cases. Antibody testing can be arranged through Janssen-Cilag at tel: 6265 8922. HSA will be closely following the investigations by the company.