No difference in patient outcomes between NNRTI- and PI-based ART

October 10, 2014

PHILADELPHIA — There was no difference in outcomes between patients assigned to non-nucleoside reverse-transcriptase inhibitor- or ritonavir-boosted protease inhibitor-based antiretroviral therapy, according to study results presented at IDWeek 2014.

“Patients with HIV initiating NNRTI- or ritonavir-boosted PI-based regimens had comparable immunological and virological outcomes, though treatment failure due to virological failure was more common among those receiving NNRTIs,” Álvaro H. Borges, MD, MSc, of the Centre for Health and Infectious Diseases Research at the University of Copenhagen in Denmark, said during his presentation.

Borges and colleagues conducted a systematic review and meta-analysis of randomized controlled trials that compared NNRTI-based regimens with regimens based on protease inhibitors boosted with ritonavir (Norvir, AbbVie). The primary endpoint was death or progression to AIDS. The researchers used intention-to-treat analyses to calculate risk ratios of virological suppression and mean differences in CD4 counts at week 48.

The analysis included 27 trials and 9,515 patients. There were 4,848 patients assigned to an NNRTI: 3,636 received efavirenz (Sustiva, Bristol-Myers Squibb) and 1,212 received nevirapine. Among the 4,667 patients assigned to a protease inhibitor, 2,661 received lopinavir/ritonavir (Kaletra, AbbVie), 1,498 received atazanavir/ritonavir and 508 patients received another protease inhibitor with ritonavir.

There were 11 trials in which death or progression to AIDS was the primary endpoint. In the NNRTI arms, 308 patients died or progressed to AIDS, as did 301 patient in the protease inhibitor arms (RR=1.03; 95% CI, 0.89-1.19). In 21 trials where death was a secondary endpoint, there were 256 deaths in the NNRTI arms and 249 in the protease inhibitor arms (RR=1.03; 95% CI, 0.87-1.21). Within the 10 trials where progression to AIDS was a secondary endpoint, 193 patients in the NNRTI arm and 184 in the protease inhibitor arm progressed (RR=1.06; 95% CI, 0.87-1.29).

The rates of treatment discontinuation were similar between the arms, but the risk of discontinuation because of protocol-defined virological failure was higher among the NNRTI-treated patients (RR=1.89; 95% CI, 1.02-3.51). At week 48, there was no difference in virological suppression or increase in CD4 counts between two groups.

“An individual patient data meta-analysis is warranted to further investigate the different adverse event profiles and the dynamics of CD4 cell response and virological suppression after the initiation of NNRTI- or protease inhibitor-based reigmens,” Borges said. – by Emily Shafer

For more information:

Borges A. Abstract 536. Presented at: IDWeek 2014; Oct. 8-12; Philadelphia.

Disclosure: Borges reports no relevant financial disclosures.