Kills Multiple Myeloma and Plasma Cell Leukemia Tumor Cells

Copenhagen, Denmark; December 12, 2005 – Genmab A/S (CSE: GEN) announced today that HuMax®-CD38 was effective in killing primary multiple myeloma cells and plasma cell leukemia cells in preclinical studies. HuMax-CD38 is a human IgG1κ antibody that targets the CD38 molecule which is highly expressed on the surface of multiple myeloma tumor cells.

HuMax-CD38 was more effective in triggering both Antibody-Dependent Cellular Cytotoxicity (ADCC) and Complement Dependent Cytotoxicity (CDC) immune system killing mechanisms than a broad array of other human CD38 antibodies when tested on a panel of over 10 primary tumors from multiple myeloma patients, confirming earlier study results. HuMax-CD38 also potently killed tumor cells from a patient with a CD38/138 positive plasma cell leukemia which was refractory to chemotherapy at the time of analysis. Plasma cell leukemia is a manifestation of multiple myeloma in which tumor cells are present in the blood.

Furthermore, HuMax-CD38 effectively prevented the growth of CD38 positive cancer cells in an animal model.

About Multiple Myeloma
Multiple myeloma is a cancer of plasma cells and accounts for approximately 1% of all cancers. The incidence of multiple myeloma is 5.2 per 100,000 people corresponding to 15,270 new cases in the US in 2004.  In the US, approximately 11,000 deaths each year are related to multiple myeloma. At present, no cure is available, and the mean survival is approximately 3 years from time of diagnosis.

“These preclinical studies indicate that HuMax-CD38 may potentially be useful in the treatment of plasma cell leukemia, in addition to multiple myeloma,” said Lisa N. Drakeman, Ph.D., Chief Executive Officer of Genmab. “We are excited by the data and are looking forward to seeing more preclinical results.”

These data are presented today by Dr. Matthias Peipp, Scientist, University of Schleswig-Holstein, Kiel, Germany, during the “Multiple Myeloma: Biology and Novel Therapeutic Approaches” poster session at the 2005 Annual Meeting of the American Society of Hematology. The poster will be available at www.genmab.com.

Conference Call
Genmab will hold a conference call about this news, as well as news from the HuMax-CD20 presentation at ASH, today, Monday, December 12, 2005 at

8:45 p.m. CET
7:45 p.m. GMT
2:45 p.m. EST

The dial in numbers are as follows:

+1 800-289-0743 (in the US) and ask for the Genmab conference call
+1 913-981-5546 (outside the US) and ask for the Genmab conference call

The conference call will be held in English.