Tenofovir DF ( TDF) has infrequently been associated with renal toxicity. Cobicistat (COBI), like ritonavir, can increase creatinine (Cr) without affecting glomerular filtration by inhibiting renal tubular creatinine secretion. We examined the renal safety of recently approved single tablet regimen STRIBILD [STB] (elvitegravir [EVG]/COBI/emtricitabine [FTC]/TDF). Pooled renal safety data through Week 48 were analysed from three STB studies (104,102, and 103) and Two COBI studies (105 and 114).
In the pooled STB studies, the median exposures to STB (n=749), ATR (n=375), and ATV/r+TVD (n=355) were 48, 59, and 48 weeks. The median (IQR) changes in Cr (mmol/L) at Week 48 in the three groups were 11.49 (5.30 to 19.44), 0.88 (-5.30 to 7.95), and 7.07 (0.88 to 15.02). The rates of renal AEs leading to study drug discontinuation (renal AE DC) were STB 1.1% (8/749), ATR 0 %, and ATV/r+TVD 0.3 % (1/355). One patient in STB reported a serious renal AE not leading to study drug discontinuation. In the pooled COBI studies, the median exposures to ATV/co+TVD (n=394) and ATV/r+TVD (n=377) were 48 weeks. The median (IQR) changes in Cr (mmol/L) at Week 48 in the two groups were 11.49 (4.42 to 19.44) and 7.95 (0.88 to 15.02). The rates of renal AE DC were ATV/co+TVD 1.5 % (6/394), ATV/r+TVD 1.6 % (6/377); two and three renal AE DCs from each group were serious AEs.
As expected, small increases in Cr were seen with the use of STB or COBI. The rates of renal event leading to study drug discontinuation with TDF-containing COBI-boosted EVG or ATV regimen were low at 1.2% (14/1143).