icon-folder.gif   Conference Reports for NATAP  
  ICAAC 2015 55th Interscience Conference
on Antimicrobial Agents and Chemotherapy
September 5-9, 2015, San Diego, CA
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Switch From Raltegravir to Rilpivirine Regimen Safe, Effective in Cohort Study
  ICAAC 2015, September 17-21, 2015, San Diego
Mark Mascolini
A large majority of people switching from a raltegravir regimen to coformulated rilpivirine/tenofovir/emtricitabine (RPV/TDF/FTC, Complera, Eviplera) maintained virologic control and improved lipid profiles, according to analysis of the La Paz HIV Cohort in Spain [1]. CD4 counts also improved after switching.
This longitudinal analysis involved adults in the La Paz HIV Cohort with a viral load below 50 copies while taking raltegravir plus TDF/FTC or abacavir/lamivudine (ABC/3TC). From January 2013 through April 2015, all simplified to fixed-dose RPV/TDF/FTC and all had at least 6 months of follow-up. The primary endpoint was the proportion of people with virologic failure (a viral load above 50 copies) 24 weeks after the switch. The La Paz team used mixed-model effect analysis adjusted by time of follow-up to evaluate changes in CD4 count, estimated glomerular filtration rate (eGFR) by the CKD-EPI method, and fasting lipids.
The 208 study participants averaged 49 years in age, 76% were men, 58.6% acquired HIV sexually, and 38.4% became infected while injecting drugs. Median time since HIV diagnosis stood at 18.8 years and median current CD4 count at 650. Most people (80%) were taking raltegravir plus TDF/FTC, and the rest were taking raltegravir plus ABC/3TC.
Twenty-four weeks after the switch to RPV/TDF/FTC, 196 people (94.2%) maintained a viral load below 50 copies. Three people (1.4%) had a load above 50 copies, 4 (1.9%) stopped the new regimen because of adverse events, and 2 (1.0) stopped because they needed to start omeprazole. After a median 17 months of follow-up, 169 people (81.2%) still had a viral load below 50 copies, 16 (7.7%) had an above-50 load, 13 (6.3%) stopped the rilpivirine regimen because of adverse events, 5 stopped because of the need to start omeprazole, and 5 others stopped because of drug abuse, loss to follow-up, inclusion in a clinical trial, HCV therapy, or an inappropriate indication. The most frequent adverse events were gastrointestinal intolerance in 5, renal complication prevention in 3, and osteopenia in 3.
Overall treatment failure incidence came to 14 per 100 person-years (meaning the regimen failed in 14 of 100 people every year). Incidence of virologic failure was 5.7 per 100, stopping for adverse events 4.7 per 100, and stopping for antiretroviral interactions 1.8 per 100.
Among 16 people with virologic failure and resistance genotyping after failure, 10 had no detectable resistance mutations, 4 with previous resistance to TDF, FTC, or RPV had the same resistance profile before and after virologic failure, and 2 without historical resistance to TDF, FTC, or RPV acquired resistance to FTC and RPV.
For the whole study group, CD4-count adjusted by day of follow-up rose by 37, a significant improvement (P = 0.027). Overall eGFR did not change through follow-up. eGFR rose marginally after the switch in people taking TDF/FTC in their previous regimen and fell slightly in those previously taking ABC/3TC, but neither of these changes was statistically significant.
Analysis of fasting lipid changes adjusted by days of follow-up indicated significant declines in total cholesterol (176 to 166 mg/dL, P < 0.001), low-density lipoprotein cholesterol (107 to 101 mg/dL, P = 0.003), and triglycerides (131 to 120 mg/dL, P = 0.038). "Good" high-density lipoprotein (HDL) cholesterol also fell slightly but significantly (43 to 41 mg/dL, P = 0.002). The researchers did not report total-to-HDL cholesterol ratio.
1. Perez-Valero I, Hontamon V, Gonzalez-Garcia J, Arribas J. Simplification to TDF/FTC/RPV from TDF/FTC or ABC/3TC plus RTG in a cohort study. ICAAC 2015, September 17-21, 2015, San Diego.