Safety, tolerability, pharmacokinetics, and Aβ levels after short-term administration of R-flurbiprofen in healthy elderly individuals

To evaluate the safety and tolerability and pharmacokinetic properties of R-flurbiprofen (Tarenflurbil) in normal elderly individuals and to determine the effect of the drug on amyloid beta 42 (Aβ42) levels, we conducted a double-blind, placebo-controlled study of 48 healthy subjects aged 55 to 80. Three successive cohorts were randomized to doses of 400, 800, or 1600 mg/d, or placebo, given as 2 divided doses for 21 days. Blood and cerebrospinal fluid were collected for pharmacokinetic studies and measurement of Aβ levels at baseline and on day 21. R-flurbiprofen was well-tolerated at all 3 doses. The compound penetrated the blood-brain barrier in a dose-dependent manner. From baseline to 21 days, comparisons between study groups revealed no significant differences in changes of cerebrospinal fluid Aβ42 levels and no significant differences in changes of plasma Aβ42 levels at the time of trough drug level at 21 days of treatment. Further analysis of drug concentration-response for plasma samples showed that at the time of peak plasma concentration, higher plasma drug concentration was related to lower Aβ42 plasma levels (P=0.016). R-flurbiprofen had an excellent safety profile and showed dose-dependent central nervous system penetration. Exploratory analyses of plasma Aβ and peak drug levels suggested a short-term effect in plasma that warrants independent verification. The safety, tolerability, and pharmacokinetic profile of R-flurbiprofen in these older individuals support the ongoing studies of this compound in patients with Alzheimer disease.