Extension of Phase I/II Arthritis Study

San Francisco, CA, USA; March 8, 2001 - Genmab A/S (CSE: GEN and Neuer Markt: GE9D) announced today positive data from an extension of its Phase I/II study of HuMax-CD4 (TM), its fully human antibody used to treat rheumatoid arthritis. In this open label study, ten patients with active rheumatoid arthritis received a single dose of HuMax-CD4 in combination with low dose methotrexate. The treatment was well tolerated, with no serious adverse events and no depletion of CD4 positive T-cells. In addition, the patients showed signs of clinical efficacy. The number of swollen joints, painful joints and physician's global assessment of disease activity were reduced with medians of 57%, 46%, and 54% respectively. Furthermore, 2 of the ten patients achieved ACR 20, objective criteria defined by the American College of Rheumatology that is used by regulatory authorities to evaluate whether a product is approvable. HuMax-CD4 is currently being evaluated in two placebo controlled, multiple dose Phase II studies, one in rheumatoid arthritis and one in psoriasis.

These data were presented today at the American College of Rheumatology's Innovative Therapies in Autoimmune Diseases conference in San Francisco by Joergen Petersen, M.D., Ph.D., Head of Rheumatology, Rigshospitalet, Copenhagen.

In the initial Phase I/II study, patients with severe rheumatoid arthritis who failed to respond to conventional therapy received a single dose of HuMax-CD4. HuMax-CD4 was well tolerated, with no drug-related serious adverse events. Furthermore, in the four highest dose cohorts, fifty per cent of the treated patients achieved ACR 20.

"This study shows that we can move into a very large patient population - those who are responding to methotrexate but still have active disease," said Lisa N. Drakeman, Ph.D., Chief Executive Officer. "There are millions of arthritis patients in the US alone and many of them are waiting for more effective treatment."

"The magnitude of response to only a single dose of HuMax-CD4 is very encouraging," said Joergen Petersen, M.D., Ph.D. "We look forward to the results of the ongoing multi-dose study."