Transport properties of valsartan, sacubitril and its active metabolite (LBQ657) as determinants of disposition

1. The potential for drug-drug interactions of LCZ696 (a novel, crystalline complex comprising sacubitril and valsartan) was investigated in vitro. 2. Sacubitril was shown to be a highly permeable P-glycoprotein (P-gp) substrate and was hydrolyzed to the active anionic metabolite LBQ657 by human carboxylesterase 1 (CES1b and 1c). The multidrug resistance-associated protein 2 (MRP2) was shown to be capable of LBQ657 and valsartan transport that contributes to the elimination of either compound. 3. LBQ657 and valsartan were transported by OAT1, OAT3, OATP1B1 and OATP1B3, whereas no OAT- or OATP-mediated sacubitril transport was observed. 4. The contribution of OATP1B3 to valsartan transport (73%) was appreciably higher than that by OATP1B1 (27%), Alternatively, OATP1B1 contribution to the hepatic uptake of LBQ657 (∼70%) was higher than that by OATP1B3 (∼30%). 5. None of the compounds inhibited OCT1/OCT2, MATE1/MATE2-K, P-gp, or BCRP. Sacubitril and LBQ657 inhibited OAT3 but not OAT1, and valsartan inhibited the activity of both OAT1 and OAT3. Sacubitril and valsartan inhibited OATP1B1 and OATP1B3, whereas LBQ657 weakly inhibited OATP1B1 but not OATP1B3. 6. Drug interactions due to the inhibition of transporters are unlikely due to the redundancy of the available transport pathways (LBQ657: OATP1B1/OAT1/3 and valsartan: OATP1B3/OAT1/3) and the low therapeutic concentration of the LCZ696 analytes.

In vitro and clinical evaluation of OATP-mediated drug interaction potential of sacubitril/valsartan (LCZ696)

WHAT IS KNOWN AND OBJECTIVE

Sacubitril/valsartan (LCZ696) has been recently approved for the treatment of heart failure (HF) patients with reduced ejection fraction. Several HF patients receive statins as co-medication.

METHODS

Because clearance of statins is meditated via OATP1B1/1B3, the inhibition potential of these transporters by LCZ696 analytes was evaluated in vitro. Furthermore, an open-label, fixed-sequence clinical study was conducted to determine the effect of LCZ696 on the exposure of simvastatin and its active metabolite simvastatin acid. In this clinical study, 26 healthy subjects received simvastatin 40 mg alone or in combination with LCZ696 or after 1 or 2 h of LCZ696 dosing.

RESULTS AND DISCUSSION

Although no significant inhibition by LBQ657 (an active metabolite of sacubitril) and valsartan was observed, sacubitril inhibited OATP1B1 and OATP1B3 in vitro, with IC50 of 1·91 and 3·81 μm, respectively. Upon co-administration of simvastatin with LCZ696, the Cmax of simvastatin and simvastatin acid decreased by 7% and 13%, respectively. When administered 1 h after LCZ696 dosing, the corresponding Cmax of simvastatin and simvastatin acid decreased by 16% and 4%, respectively. When administered 2 h after LCZ696 dosing, the Cmax of simvastatin decreased by 33% and that of simvastatin acid increased by 16%. However, no notable changes were observed in the AUCs of simvastatin or simvastatin acid upon co-administration or time-separated administration with LCZ696. No notable impact of simvastatin co-administration was observed on the pharmacokinetics of LCZ696 analytes. LCZ696 and simvastatin were generally well tolerated when administered alone or in combination.

WHAT IS NEW AND CONCLUSIONS

Overall, the results of this study suggest that although sacubitril inhibited OATP1B1 and OATP1B3 in vitro, it does not translate into any clinically relevant in vivo effect.