1st National Conference Human Retroviruses and Related Infections Washington, DC - December 12-16, 1993

Natl Conf Hum Retrovir Relat Infect 1993 Dec 12-16;1: (abstract no. 2)

Montaner JS, Wainberg M, Rachlis A, Gill J, Beaulieu R, Schlech W, Tsoukas C, O’Shaughnessy M, Raboud J, Smaldone L
Canadian HIV Trials Network, Canada

OBJECTIVE: To compare the effects of ddI (Videx®) vs continued AZT (Retrovir®) in HIV+ individuals with CD4’s 200 to 500/mm³ treated with AZT for ≥6 months.

METHODS: Patients were randomized to AZT (600 mg/d) or ddI (powder formulation; 334 or 500 mg/d for weights less than or ≥60 kg). Monthly evaluations were completed Oct. ’92.

RESULTS: Out of 232 patients studied, 60% were asymptomatic, 30% had ARC and 10% had AIDS. Mean baseline CD4 was 328 and 334 cells/mm³ for the ddI (n=113) and the AZT (n=119) groups, respectively. Change to ddI lead to a rapid and significant increase in baseline CD4’s persisting for ≥36 weeks. The Δ CD4’s was of 47 and 90 cells/mm³ at 4 and 24 weeks (p<0.001) in favor of ddI. Viral studies, in 102 (ddI:49; AZT:53) unselected patients, showed that 21% and 28% of the ddI and AZT groups were AZT-resistant (p=NS), at entry. No further AZT-resistance developed during the study in the ddI group. In contrast, the probability of developing AZT- resistance was 59% at one year, for the AZT group (p=0.01). Cross resistance was present in ≤10% of patients in each group (p=NS). No new ddI resistance was observed during the study (≥1 year). A change in ddI led to a decrease in mean IC₅₀ for AZT among AZT-resistant patients. The beneficial effects of ddI on CD4 count and in vitro resistance were present in patients harboring syncytium inducing (SI) or non-SI virus at entry.

CONCLUSION: Our results demonstrate that an early change to ddI leads to a sustained increase in CD4 count, prevents in vitro resistance and often leads to a decrease in IC₅₀ if AZT resistance is present. These effects are independent of viral phenotype.

Keywords: AIDS Vaccines, AIDS-Related Complex, Acquired Immunodeficiency Syndrome, Anti-HIV Agents, Antigens, CD4, CD4 Lymphocyte Count, Didanosine, HIV, HIV Infections, HIV Protease Inhibitors, HIV Seropositivity, Humans, In Vitro, Zidovudine, immunology

Download abstract

1993-12-12
2

Copyright © 1993 - The American Society for Microbiology. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the American Society for Microbiology.