Preliminary Safety Data on 17 Patients Shows Favorable Safety Profile

Copenhagen, Denmark; November 5, 2004 – Genmab A/S (CSE: GEN) announced today that the company will present a body of safety and efficacy data from a HuMax-CD20 Phase I/II study to treat patients with non-Hodgkin’s lymphoma (NHL) at the 46th American Society of Hematology (ASH) Annual Meeting and Exposition in San Diego, California December 4-7, 2004. Preliminary safety data on 17 patients available at the time the abstract was completed shows a favorable safety profile and significant depletion of peripheral blood B-cells.

The data will be presented by Anton Hagenbeek, Professor of Hematology at the University Medical Center Utrecht on December 4 between 6 and 7:30 pm local time. An abstract for the presentation is now publicly available at the ASH website http://www.abstracts2view.com/hem_sandiego2004.

About the trial

The dose escalation trial is ongoing. Ten patients in each of 4 dose groups receive 4 weekly doses of 300, 500, 700 or 1000mg of HuMax-CD20. The patients are followed for a period of 12 months. The trial is designed to show both safety and efficacy data.

About HuMax-CD20

HuMax-CD20 is a human antibody which is effective at binding to the disease target, and releases only very slowly from the target over time. In February 2003, Genmab presented data from pre-clinical laboratory tests showing HuMax-CD20 appeared to kill tumor cells from cancer patients who had Chronic Lymphocytic Leukemia (CLL) that were resistant to rituximab, a marketed cancer therapy. The data showed the antibody highly effective in inducing complement mediated cytotoxicity (cell destruction) of B-cell tumors. Subsequently, Genmab has collected data that appears to show HuMax-CD20 is also effective in inducing Natural Killer cell-mediated cytotoxicity of B-cell tumors. Further, in a 92 day primate study, HuMax-CD20 effectively depleted B-cells from blood and lymph nodes.  In this study, HuMax-CD20 appeared to deplete B-cells for a period of time that was four times longer than rituximab. 

In another study it was found that HuMax-CD20 binds to a unique site on CD20 target cells when compared to other known CD20 antibodies. This is a distinguishing characteristic of HuMax-CD20 and may help explain why HuMax-CD20 has outperformed other CD20 antibodies in a variety of pre-clinical studies. Furthermore, in a novel cancer disease model in immuno-compromised mice using sensitive bio-luminescence imaging, new data show that HuMax-CD20 appears to stop growth of B-cell tumors grown from a laboratory cell line far more effectively than either placebo, or rituximab.