T Eley, Y-H Han, S-P Huang, B He, W Li, W Bedford, M Stonier, D Gardiner, K Sims, P Balimane, D Rodrigues, RJ Bertz

Transcription

1 IN VIVO AND IN VITRO ASSESSMENT OF ASUNAPREVIR (ASV; BMS ) AS AN INHIBITOR AND SUBSTRATE OF ORGANIC ANION TRANSPORT POLYPEPTIDE (OATP) TRANSPORTERS IN HEALTHY VOLUNTEERS T Eley, Y-H Han, S-P Huang, B He, W Li, W Bedford, M Stonier, D Gardiner, K Sims, P Balimane, D Rodrigues, RJ Bertz 7 th International Workshop on Clinical Pharmacology of Hepatitis Therapy Cambridge MA, USA June 2012 Oral presentation O_04

2 Disclosures All authors are full-time employees of Bristol-Myers Squibb TE, Y-HH, S-PH, BH, WL, MS, DG, KS, PB, DR, RJB are stockholders of Bristol-Myers Squibb

3 Background: Asunaprevir (ASV, BMS ) Potent, selective inhibitor of the HCV NS3 protease In vitro activity against HCV GT 1 and 4 Currently in Phase 3 trials as part of DUAL/QUAD therapy in patients with HCV GT 1 and 4 with daclatasvir (DCV) +/- peg-alfa/rbv Preclinical data demonstrated ASV inhibits OATP1B1 and OATP1B3 with IC 50 values of 0.3µM and 3.0µM, respectively Steady state plasma C max for 200 mg BID Phase 2 tablet with food ~ ng/ml (~ nM) with CV in the 60-80% range Plasma protein binding of >99% High liver:plasma ratio in animals (40 359x); NS3 PI class related High SVR rates with low plasma concentrations; liver distribution important clinically 83% SVR24 with ASV/peg-alfa/RBV in treatment naive HCV patients 90% SVR4 with ASV+DCV+peg-alfa/RBV in interferon null responders BID, twice daily; CV, coefficient of variation; HCV, hepatitis C virus; GT, genotype OATP: Organic anion-transporting polypeptide; Peg-alfa, pegylated interferon alfa; RBV, ribavirin

4 Organic Anion Transporting Polypeptides OATPs known to transport Bile acids, bilirubin Steroid and bilirubin conjugates Thyroid hormones HMGCo-A reductase inhibitors Methotrexate Glyburide Rifampin Angiotensin receptor blockers Multiple clinically relevant DDIs Preferential liver distribution suggests involvement of OATP Image excerpted from Giacomini, et al, for ITC, Nature Reviews Drug Discovery Mar 2010

5 No Apparent Involvement of Active Uptake into Hepatocytes at 1 μm ASV (1 µm) 40 ASV (lowest conc. 1 µm) 1 mm TEA 1 mm PAH 100 µm Taurocholate 50 µm BSP Uptake (nmol/mg/min) Control Uptake (% of control) No significant inhibition by transporter inhibitors a t 1 µm ASV showed high permeability in CaCo-2 and PAMPA assays No difference in uptake in over-expressed systems (not shown) TEA, tetraethylamine ; PAH, para-aminohippuric acid, BSP: sulfobromophthalein Concentration (µm)

6 Study AI447015: Evaluation of ASV as an OATP Inhibitor Aim: to assess the effect of ASV on the PK of rosuvastatin 20 healthy male and female subjects, ages 18-49, BMI kg/m 2 Single sequence crossover study design Day 7 SD RST 10 mg 72 hr PK Days days of ASV 200 mg BID with meals Days SD RST 10 mg 72h PK with ASV continuing at 200 mg BID throughout BID, twice daily; SD, single dose; RST, rosuvastatin

7 Study AI447015: ASV Increases Rosuvastatin Exposures Mean (+/- SD) RST concentration (ng/ml) Parameter C max (ng/ml) Geo. LSM AUC t (ng*hr/ml) Geo. LSM AUC inf (ng*hr/ml) Geo. LSM Time post dose (hours) ASV effect on rosuvastatin pharmacokinetics Treatment C Treatment E Geo. LSM Ratio (RST) (BMS + RST) (90 % CI) (n=20) (n=20) ( ) (n=20) (n=20) ( ) (n=16) (n=18) ( ) LSM, least-squares mean, RST, rosuvastatin

8 Study AI447015: Weak OATP Inhibition by ASV Weak OATP Inhibition by ASV ASV increased rosuvastatin exposure Based on AUC inf this effect can be characterized as weak inhibition of OATP1B1/1B3 by ASV Examples of strong OATP inhibitors Cylcosporine increases pravastatin AUC 9.9x; rosuvastatin AUC 7.1x LPV/RTV increases bosentan AUC 5.48x Clinically relevant interactions are unlikely to exist between ASV and most OATP substrates Still precautionary medications in Phase 3

9 Study AI447018: Evaluation of ASV as an OATP Substrate Aim: to assess the effect of single dose rifampin on the PK of ASV ASV given fasted 20 healthy male subjects, ages 18-49, BMI kg/m 2 Single sequence crossover study design Day 1 SD RIF 600 mg with 200 mg SD ASV (fasted) 48h PK Day mg SD ASV (fasted) 48h PK RIF, rifampin; SD, single dose

10 Study AI447018: Rifampin Increases ASV Exposure Concentration (ng/ml) Treatment and Comparison C max (ng/ml) adjusted geo. mean AUC inf (ng*h/ml) adjusted geo. mean Rifampin effect on ASV pharmacokinetics Treatment A (ASV + RIF) 1214 (n=20) 6045 (n=20) Treatment B (ASV) (n=20) (n=20) GMR (90% CI) (14.27, 31.24) (11.22, 19.53) Time (h) CI, confidence interval; Geo, geometric; GMR, geometric mean ratio; RIF, rifampin; TRT, treatment

11 Study AI447018: Wide Range of Effect of Single Dose Rifampin C max by treatment Cmax by Treatment AI AUC inf by treatment AUCinf by Treatment AI Cmax (ng/ml) AUCinf (ng*h/ml) With rifampin Control With rifampin Control Individual changes in C max range from ~4.8x to ~222x Individual changes in AUC inf range from ~4.9x to ~67x 11

12 Study AI447018: ASV Exposure Increased by Single Dose Rifampin Results indicate that ASV is a sensitive substrate of OATP-mediated uptake with a wide range of effect Although passive distribution plays a greater role at higher concentrations, there is clearly an active component at lower concentrations Strong OATP inhibitors may reduce antiviral activity of ASV ASV 200 mg single dose fasted tablet had C max well below 1μM

13 Saturable, Transporter-mediated Uptake: Hepatic Uptake via OATP1B1 and OATP2B1 HEK-293 cells Hepatocytes 5 ASV (10 nm) ASV (10 nm) + RIF (50 µm) 180 Uptake rate (pmol/min/mg) Uptake rate (pmol/min/mg) Km = 0.68µM 0 Mock OATP2B1 OATP1B1 OATP1B ASV concentration (µm) 13

14 . Clinically Relevant Genetic Polymorphisms in OATP1B1 Transporter (old name) Gene name Polymorphism rs number Common haplotype Amino acid change Comment OATP1B1 (LST1, OATP-C, OATP2) SLCO1B1 388A G rs SLCO1B1*1b 130Asn Asp Increased activity 521T C rs SLCO1B1*5, *15, *17 174Val Ala Reduced activity OATP1B1 allelic frequency varies with ethnic group 388G present in 40% of Caucasians, 75% of African Americans and 60% of Asians 521T present in 15% of Caucasians, 2% of African Americans and 15% of Asians Enhanced and reduced function haplotypes likewise vary Correlated with adverse events and pharmacokinetics E. Link et al (2008): OATP1B1 variants linked to simvastatin-induced myopathy L. Ramsey, et al (2012): OATP1B1 variants explain 10.7% of population variability in methotrexate clearance

15 Summary and Conclusions In vivo, ASV increases the plasma exposure of the OATP1B1 and OATP1B3 probe rosuvastatin by weakly inhibiting liver uptake Single dose rifampin markedly increases ASV plasma exposure ASV has been shown to be a substrate of OATP1B1/OATP2B1 in vitro OATP-mediated transport affects the disposition of ASV and likely contributes to the observed pharmacokinetic variability of the compound More data to be collected from ongoing studies to determine OATP1B1 and 2B1 subtypes to evaluate their potential effect on ASV plasma PK