Ocular Pharmacology and Toxicology of TRPV1 Antagonist SAF312 (Libvatrep).

Purpose: To evaluate the pharmacology and toxicology of SAF312, a transient receptor potential vanilloid 1 (TRPV1) antagonist. Methods: TRPV1 expression in human ocular tissues was evaluated with immunohistochemistry. Inhibition of calcium influx in Chinese hamster ovary (CHO) cells expressing human TRPV1 (hTRPV1) and selectivity of SAF312 were assessed by a fluorescent imaging plate reader assay. Ocular tissue and plasma pharmacokinetics (PK) were assessed following a single topical ocular dose of SAF312 (0.5%, 1.0%, 1.5%, 2.5%) in rabbits. Safety and tolerability of SAF312 were evaluated in rabbits and dogs. Effects of SAF312 on corneal wound healing after photorefractive keratectomy (PRK) surgery were assessed in rabbits. Results: TRPV1 expression was noted in human cornea and conjunctiva. SAF312 inhibited calcium influx in CHO-hTRPV1 cells induced by pH 5.5 (2-[N-morpholino] ethanesulfonic acid), N-arachidonoylethanolamine, capsaicin, and N-arachidonoyl dopamine, with IC50 values of 5, 10, 12, and 27 nM, respectively, and inhibition appeared noncompetitive. SAF312 demonstrated high selectivity for TRPV1 (>149-fold) over other TRP channels. PK analysis showed highest concentrations of SAF312 in cornea and conjunctiva. SAF312 was found to be safe and well tolerated in rabbits and dogs up to the highest feasible concentration of 2.5%. No delay in wound healing after PRK was observed. Conclusions: SAF312 is a potent, selective, and noncompetitive antagonist of hTRPV1 with an acceptable preclinical safety profile for use in future clinical trials. Translational Relevance: SAF312, which was safe and well tolerated without causing delay in wound healing after PRK in rabbits, may be a potential therapeutic agent for ocular surface pain.

Pharmacokinetic drug-drug interaction assessment of LCZ696 (an angiotensin receptor neprilysin inhibitor) with omeprazole, metformin or levonorgestrel-ethinyl estradiol in healthy subjects.

LCZ696 is a novel angiotensin receptor neprilysin inhibitor in development for the treatment of cardiovascular diseases. Here, we assessed the potential for pharmacokinetic drug-drug interaction of LCZ696 (400 mg, single dose or once daily [q.d.]) when co-administered with omeprazole 40 mg q.d. (n = 28) or metformin 1000 mg q.d. (n = 27) or levonorgestrel-ethinyl estradiol 150/30 µg single dose (n = 24) in three separate open-label, single-sequence studies in healthy subjects. Pharmacokinetic parameters of LCZ696 analytes (sacubitril, LBQ657, and valsartan), metformin, and levonorgestrel-ethinyl estradiol were assessed. Omeprazole did not alter the AUCinf of sacubitril and pharmacokinetics of LBQ657; however, 7% decrease in the Cmax of sacubitril, and 11% and 13% decreases in AUCinf and Cmax of valsartan were observed. Co-administration of LCZ696 with metformin had no significant effect on the pharmacokinetics of LBQ657 and valsartan; however, AUCtau,ss and Cmax,ss of metformin were decreased by 23%. Co-administration of LCZ696 with levonorgestrel-ethinyl estradiol had no effect on the pharmacokinetics of ethinyl estradiol and LBQ657 or AUCinf of levonorgestrel. The Cmax of levonorgestrel decreased by 15%, and AUCtau,ss and Cmax,ss of valsartan decreased by 14% and 16%, respectively. Co-administration of LCZ696 with omeprazole, metformin, or levonorgestrel-ethinyl estradiol was not associated with any clinically relevant pharmacokinetic drug interactions.