BUENOS AIRES, ARGENTINA -- July 10, 2001 -- Data presented today at the 1st International AIDS Society (IAS) Conference on HIV Pathogenesis and Treatment here indicate that patients who substituted DuPont Pharmaceuticals' anti-HIV drug Sustiva™ (efavirenz), a non-nucleoside reverse transcriptase inhibitor (NNRTI), for a protease inhibitor (PI) in a suppressive PI-containing regimen successfully maintained viral load suppression for a longer period of time than patients who remained on their protease inhibitor-containing regimen.
The findings from DMP Study 266-049 suggest that this treatment strategy may allow for improved long-term treatment success in HIV-positive patients who switched to a regimen containing Sustiva from a PI-containing regimen.
The results, using the non-completer=failure analysis, indicate that of the 209 patients randomized to change from a protease inhibitor to Sustiva while maintaining their two nucleoside reverse transcriptase inhibitors (NRTIs), 175 (84 percent) maintained virologic response of less than 50 copies/mL at 48 weeks. This is compared to 76 (73 percent) of the 104 patients randomized to maintain their initial regimen consisting of a protease inhibitor plus two NRTIs.
These differences were statistically significant (p=0.026.) The increase in CD4 cell count was statistically significant for both groups (Sustiva arm - 63 cells/mm3; protease inhibitor arm - 66 cells/mm3, p=0.0001.)
In addition, 15 percent of patients in the arm that continued to receive their original protease inhibitor-containing regimen experienced virologic rebound (viral load greater than 50 copies/mL) compared to 7 percent of patients in the arm containing Sustiva. These data were also statistically significant (p=0.024.)
"The results show that substituting Sustiva for a protease inhibitor effectively maintains the viral response seen with protease inhibitors," said Anita Rachlis, M.D., Professor of Medicine and Head of the Division of Infectious Diseases, Sunnybrook and Women's College Health Sciences Centre, University of Toronto. "In clinical practice, this provides an option for patients who want to remove protease inhibitors from their treatment while maintaining virologic control."
Adherence data were also collected via a questionnaire filled out by study participants to capture the number of missed doses. Twenty-nine percent of patients (N=99) in the protease inhibitor-containing arm missed doses on multiple clinic visits compared to 12 percent (N=205) in the arm containing Sustiva. These data were statistically significant (p value less than 0.001).
Study DMP 266-049 is a prospective, randomized, multicenter, open-label 48-week study of 346 antiretroviral-experienced, NNRTI-naive patients who were receiving their first protease inhibitor-containing regimen. Patients receiving a regimen containing protease inhibitor(s) plus NRTIs with plasma HIV-RNA levels less than or equal to 50 copies/mL were enrolled and then
randomized (2:1) to maintain the original NRTI regimen and substitute the protease inhibitor(s) with 600 mg of Sustiva once-daily or continue with their existing regimen.
Safety data from DMP 266-049 show that 18 percent (19/120) discontinued in the protease inhibitor-containing arm due to adverse experiences compared to 11 percent (24/226) in the arm containing Sustiva.
SOURCE: DuPont Pharmaceuticals Company
Related Links: Sustiva (efavirenz) and DuPont Pharmaceuticals Company.
