PNH Diagnosis

Alexion continues to investigate the frequency of PNH across various disease populations. PNH has been commonly identified among patients with diseases of the bone marrow, including those with Aplastic Anemia (AA) and Myelodysplastic Syndrome (MDS).24 Patients with AA and MDS are often treated with drugs that suppress their immune system to prevent their white blood cells from destroying their own bone marrow. Another possible treatment is bone marrow transplantation which is a procedure that carries considerable mortality risk.3,25

The presence of even a small number of PNH cells in patients with AA or MDS is medically important to choosing a treatment, as the presence of PNH cells may indicate a higher likelihood of a good response to immunosuppression rather than risk bone marrow transplantation.3

Alexion is sponsoring a large study called EXPLORE (EXamination of PNH, by Level Of CD59 on REd and white blood cells) which will eventually test almost 6,000 patients, to determine the frequency of PNH cells in patients with AA, MDS and other bone marrow failure syndromes. When completed, the results are expected to help define who should be tested for PNH and how the test should be conducted.24,26,27 Interim results of the EXPLORE trial were presented in May 2009 at the American Society of Clinical Oncology annual meeting.

As a result of our disease education efforts, a growing number of U.S. physicians are seeking to identify and treat more patients with Soliris as well as implement standardized diagnostic pathways for appropriate patients – those with a greater likelihood of having PNH. These include patients with hemolytic anemia, hemoglobinuria, aplastic anemia, myelodysplastic syndromes, unexplained cytopenia, or unexplained blood clots.