The effect of LCZ696 (sacubitril/valsartan) on amyloid-β concentrations in cerebrospinal fluid in healthy subjects

AIMS

LCZ696 (angiotensin receptor neprilysin inhibitor) is a novel drug developed for the treatment of heart failure with reduced ejection fraction. Neprilysin is one of multiple enzymes degrading amyloid-β (Aβ). Its inhibition may increase Aβ levels. The potential exists that treatment of LCZ696, through the inhibition of neprilysin by LBQ657 (an LCZ696 metabolite), may result in accumulation of Aβ. The aim of this study was to assess the blood-brain-barrier penetration of LBQ657 and the potential effects of LCZ696 on cerebrospinal fluid (CSF) concentrations of Aβ isoforms in healthy human volunteers.

METHODS

In a double-blind, randomized, parallel group, placebo-controlled study, healthy subjects received once daily LCZ696 (400 mg, n = 21) or placebo (n = 22) for 14 days.

RESULTS

LCZ696 had no significant effect on CSF AUEC(0,36 h) of the aggregable Aβ species 1-42 or 1-40 compared with placebo (estimated treatment ratios 0.98 [95% CI 0.73, 1.34; P = 0.919] and 1.05 [95% CI 0.82, 1.34; P = 0.702], respectively). A 42% increase in CSF AUEC(0,36 h) of soluble Aβ 1-38 was observed (estimated treatment ratio 1.42 [95% CI 1.05, 1.91; P = 0.023]). CSF levels of LBQ657 and CSF Aβ 1-42, 1-40, and 1-38 concentrations were not related (r(2) values 0.022, 0.010, and 0.008, respectively).

CONCLUSIONS

LCZ696 did not cause changes in CSF levels of aggregable Aβ isoforms (1-42 and 1-40) compared with placebo, despite achieving CSF concentrations of LBQ657 sufficient to inhibit neprilysin. The clinical relevance of the increase in soluble CSF Aβ 1-38 is currently unknown.

Pharmacokinetics of serelaxin in patients with severe renal impairment or end-stage renal disease requiring hemodialysis: A single-dose, open-label, parallel-group study

Serelaxin, a recombinant human relaxin-2 hormone, is in clinical development for treating acute heart failure. This open-label, parallel-group study investigated serelaxin pharmacokinetics (PK) after a single 4-hour intravenous infusion (10 µg/kg) in patients with severe renal impairment (n = 6) or end-stage renal disease (ESRD) requiring hemodialysis (PK on the day of dialysis [n = 6] or during dialysis-free interval [n = 6]), compared with matched healthy subjects (n = 18). In all participants, serum serelaxin concentration peaked at the end of infusion and subsequently declined with mean terminal elimination half-life of 6.5-8.8 hours. Compared with healthy subjects, a moderate decrease in serelaxin systemic clearance (37%-52%) and increase in its exposure (30%-115%) were observed in all patients. During the 4-hour hemodialysis in ESRD patients, 30% serelaxin was removed, with hemodialysis clearance constituting approximately 52% of total systemic clearance. Serelaxin was well tolerated with no deaths, serious adverse events (AE), or AE-related discontinuations. Antiserelaxin antibodies were not detected in any participant. Given the shallow dose-response relationship observed with serelaxin in clinical studies and its wide therapeutic window, the observed PK differences in patients with severe renal impairment compared with healthy subjects are unlikely to pose a safety risk and do not warrant a predefined dosage adjustment in such patients.