AnorMED Inc has initiated enrollment into a Phase I trial in healthy volunteers to evaluate the safety of AMD070 for the treatment of HIV infection. AMD070 targets the CXCR4 chemokine receptor and prevents HIV from entering and infecting healthy cells. CXCR4 and CCR5 inhibitors belong to the new investigational class of antiretroviral drugs known as HIV entry inhibitors.

"Recent clinical results indicate that CXCR4 using strains of HIV affect approximately 40% of patients and that these strains are more damaging to the immune system than CCR5 using strains. Given the increasing amount of evidence we believe CXCR4 inhibitors have an important role to play in the treatment of HIV," said Dr. Gary Calandra, Vice President Clinical Development, AnorMED Inc.

This new study is being conducted in collaboration with the U.S. Adult AIDS Clinical Trials Group (ACTG) and will enroll up to 48 healthy volunteers at two centers in the U.S. Based on positive data, the Company plans to initiate a Phase Ib/IIa clinical trial with HIV patients in 2004. AnorMED plans to present Phase I safety data early in 2004 and is also exploring potential partnering opportunities for use of AMD070 in combination with other HIV therapeutics.

ACTG is the largest HIV trials organization in the world and has played a key role in providing important data for HIV/AIDS treatment and prevention strategies. The ACTG is composed of, and directed by, leading clinical scientists in HIV/AIDS therapeutic research that is supported by grants from the Division of AIDS, a division of the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, U.S. Department of Health and Human Services.

CXCR4 is a chemokine receptor. Chemokine receptors expressed on the surface of immune cells are known to play a critical role in virus infection and transmission. CXCR4, and another chemokine receptor CCR5, are involved in HIV infection. In order to enter and infect cells, HIV must bind to either the CXCR4 or CCR5 chemokine receptor. Different strains of HIV prefer one receptor or the other, or may use either receptor to infect cells. An infected individual may harbor different levels of both CXCR4 and CCR5-using strains.