Medarex Inc announced the initiation of a Phase I clinical trial of MDX-010, a fully human anti-CTLA-4 antibody, for patients infected with HIV, the causative agent of AIDS.

This multi-center, open-label clinical trial is expected to enroll up to 18 patients with HIV who have an extensive treatment history but whose virus is no longer suppressed by highly active antiretroviral therapy (HAART). Patients are expected to receive two monthly doses of the MDX-010 antibody in this dose-escalation study. The trial is designed to establish safety and tolerability of MDX-010 in patients infected with HIV, and to preliminarily evaluate clinical efficacy. The trial will include assessments of viral load and CD4 counts in patients, as well as immune responses to HIV and other antigens.

"We believe that MDX-010 is showing promise in cancer treatment, and that it may also have the potential to enhance the immune systems of AIDS patients," said Donald L. Drakeman, President and CEO of Medarex.

"The ability to boost the potency of the cellular immune response against HIV could be crucial in allowing patients to control the virus with their own immune systems," said Israel Lowy, Director of Infectious Diseases at Medarex. "If MDX-010 can boost anti-HIV immunity, this may allow patients to require less medication, or perhaps be weaned from the necessity of lifelong HAART, with its attendant challenges of treatment toxicities and requirements for strict adherence."