A Randomized, Double-Blind, Placebo-Controlled Clinical Trial of a Chemokine Receptor 5 (CCR5) Antagonist to Decrease...

Immune Reconstitution Inflammatory Syndrome (IRIS) is a common complication of antiretroviral therapy (ART) in HIV-infected patients. IRIS is associated with an increased risk of hospitalization and death. We ascertained whether CCR5 blockade using maraviroc reduces the risk of IRIS.

The CADIRIS study was a randomized, double-blind, placebo-controlled, clinical trial that accrued subjects from five clinical sites in Mexico and one in South Africa between November 2009 and January 2012, and followed them for one year. The primary outcome was occurrence of IRIS by 24 weeks. HIV-infected adults, naïve to ART, with CD4 cells <100/microL, and HIVRNA >1,000 copies/mL were eligible. We screened 362 subjects; 279 met inclusion criteria, 3 refused participation, and 276 were randomized. Participants received maraviroc 600 mg twice daily or placebo added to an ART regimen that included tenofovir, emtricitabine, and efavirenz for 48 weeks.

There were 276 patients randomized (140 received maraviroc and 136 placebo). There was no difference in the time to IRIS events between treatment arms (HR 1·08, 95% CI (0·66, 1·77), log-rank test p=0·743). In total, 64 (23%) patients had IRIS events, 33 (24%) in the maraviroc arm and 31 (23%) in the placebo arm (p=0·88).

Maraviroc had no significant effect on frequency, time or severity of IRIS events after ART initiation. Including a CCR5 inhibitor in an initial treatment regimen does not confer a meaningful protection from the occurrence of IRIS in persons with advanced HIV infection.

The trial was funded as investigator initiated research by Pfizer Inc, New York, NY, USA.

ClinicalTrials.gov. ID: NCT00988780 (http://clinicaltrials.gov/ct2/show/NCT00988780).