Observational cohort study of rilpivirine (RPV) utilization in Europe. AIDS Research and Therapy
Cozzi-Lepri et al. studied prescription patterns and clinical outcomes associated with the use of rilpivirine (RPV) compared with efavirenz (EFV) in the EuroSIDA cohort.
Between the first availability of RPV in the countries that participate in EuroSIDA (November 2011) and December 2017, 1’355 individuals received RPV-containing and 333 EFV-containing antiretroviral therapy (ART). The proportion of treatment-naïve individuals was 11% in the RPV group, compared to 55% in the EFV group.
Compared to individuals who had been prescribed EFV, those who received RPV had a lower CD4 cell nadir (169 vs 224 cells/μL) and were more likely to have acquired HIV through heterosexual contacts. The probability of receiving RPV was highest in West Central and Southern Europe, and lowest in Eastern Europe. Among 498 who discontinued RPV, the most common physician-reported reason was treatment failure (n = 29, 5.8%), followed by renal toxicity (n = 20, 4%). Confirmed detectable HIV viral load (>50 cp/mL) occurred in 71 individuals who received RPV-based ART, with a cumulative probability at 1 year of 1.5% (95% CI 0.7-2.2), and of 4.5% (95% CI 3.3-5.7) after 2 years. Of those 71 individuals, 15 had resistance testing data available, and 5 (33%) had evidence of treatment-emergent resistance mutations.
In conclusion, in this large European cohort with 1’355 individuals who received RPV, the cumulative probability of confirmed HIV replication remains low. However, among the people with replicating HIV and available resistance data, a substantial proportion developed treatment-emergent resistance. These findings highlight the need to perform resistance testing in individuals with treatment failures.