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Pharmacokinetic Evaluation of a Drug Transporter Cocktail Consisting of Digoxin, Furosemide, Metformin, and Rosuvastatin
Mitchell E. Taub ITCW3 Meeting – Transporters in Drug Development March 14, 2017
Project team: Thomas Ebner, Thomas Giessmann, Naoki Ishiguro, Fabian Muller, Ashish Sharma, Peter Stopfer, Mitchell Taub, Heike Zimdahl-Gelling
Outline
Background and challenges
Regulatory perspectives
Transporter cocktail design Literature survey
In vitro studies
Clinical cocktail – Study 1
Clinical cocktail – Study 2
2
Background – rationale
• In vitro and in vivo studies to evaluate the potential for transporter-based DDIs are required by regulatory authorities
• Drug transporters generally exhibit broad substrate specificity
• In vitro data generated using different experimental systems can be highly variable
• Regulatory agencies cautiously evaluate in vitro transporter data • Can result in an increase in the number of clinical DDI studies
• Probe drug cocktail approach may be applied to simultaneously assess multiple potential DDIs established for CYP450s • However, this has not yet been defined/established for transporters
Goal: Develop a readily accessible cocktail approach, using transporter substrate drugs available globally, applicable in an industrial drug development setting
3
Cooperstown cocktail: phenotyping data, CYP450 probes Streetman et al. (2000) CPT, 68:375
4
C Y P 1 A 2
Me
dia
n V
alu
e (
ran
ge
)
Ind iv id
u a l
C o c k tail
0
1
2
3
4
5
C Y P 2 C 1 9
Me
dia
n V
alu
e (
ran
ge
)
Ind iv id
u a l
C o c k tail
0 .0
0 .5
1 .0
1 .5
2 .0C Y P 3 A
Me
dia
n V
alu
e (
ran
ge
)
Ind iv id
u a l
C o c k tail
0
2 0 0
4 0 0
6 0 0
8 0 0
Caffeine (P, M)
Omeperazole (P, M)
Midazolam, IV (CL)
Also included: CYP2D6, N-acetyltransferase-2, xanthine oxidase
5
Ieiri et al. (2009) Expert Opinion in Drug Metabolism and Toxicology, 5: 703-729 Muller and Fromm (2011) Pharmacogenomics, 12: 1017-1037
Drug P-gp BCRP MRP2 OATP 1A2
OATP 1B1
OATP 1B3
OATP 2B1
OAT1 OAT3 OCT2 MATE1
Cimetidine S S / I S / I
Cyclosporine A I I I I
Estradiol-17β-D-glucuronide S S S S
Fexofenadine S S S S
Methotrexate S S S S S
Pravastatin S S S S S S S
Probenecid S S
Rifampin S / I S / I
Rosuvastatin S S S S
Drugs that are shown to interact with one transporter typically interact with multiple transporters
Thus, multiple pathways for clearance are possible for transporter substrates
Transporter interaction redundancy
Theoretical maximum statin AUC increase (pathway) Elsby et al (2012) CPT, 92(5):584-598
Simvastatin Atorvastatin Fluvastatin Pitavastatin Pravastatin Rosuvastatin CYP3A4, CYP2C9 OATP1B1, OATP1B3 NTCP, BCRP, OAT3
FDA guidance on DDIs cocktail studies
FDA – Guidance for Industry – Drug Interaction Studies (2012, draft)
• Simultaneous administration of a mixture of substrates of multiple CYP enzymes and transporters in one study (i.e., a “cocktail approach”) in human volunteers is another way to evaluate a drug’s inhibition or induction potential, provided that the study is designed properly and the following factors are present:
• (1) the substrates are specific for individual CYP enzymes or transporters;
• (2) there are no interactions among these substrates;
• (3) the study is conducted in a sufficient number of subjects.
• Negative results from a well-conducted cocktail study can eliminate the need for further evaluation of particular CYP enzymes and transporters.
• The data generated from a cocktail study can supplement data from other in vitro and in vivo studies in assessing a drug’s potential to inhibit or induce CYP enzymes and transporters.
7
EMA guidance on DDIs cocktail studies
EMA – Guideline on the Investigation of Drug Interactions (2015)
• It is possible to use so called “cocktail studies” to investigate the effects of an investigational drug on several enzymes and transporters in one in vivo study.
• In vivo cocktail studies may also be used to replace studies of the in vitro inhibition and induction potential of parent drug (and metabolites) on enzymes (and transporters).
• It should have been demonstrated in vivo that the probe drugs combined in the “cocktail” do not interact with each other.
• If satisfactorily performed, the results of the cocktail studies can be extrapolated to other drugs and can be used to support treatment recommendations in the SmPC.
8
In vivo transporter cocktail project Stage 1 Stage 2
Seek advice and opinion of key experts and opinion leaders Assessment of practical application of substrate/inhibitor combinations Initial estimate of scope and extent of clinical program Propose various scenarios and recommendation for proceeding into Stage 2
Stage 1: Orientation and concept building
Stage 2: Assessment of cocktails and clinical validation
Check for mutual interactions using the (4) selected cocktail substrates Test the effect of transporter inhibitors
PK properties of proposed transporter cocktail drugs Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
Digoxin
(P-gp)
Rosuvastatin
(OATP, BCRP)
Furosemide
(OAT1, OAT3)
Metformin
(OCT2, MATEs)
Dose in cocktail (mg) 0.25 10 5 500
Half-life (h) 18 - 36 21 2 1.7 - 4.5
Bioavailability (%) 60 - 80 (tablet) 20 65 (tablet) 50 - 60
PPB (fu, %) 75 12 1.3 - 4.1 100
Route of elimination (i.v. dosing)
51% urine 15% feces
28% urine 83% urine 7.5% feces
100% urine
Metabolism minor minor, ~20% minor negligible
In vitro transporter (recommended by guidelines)
P-gp, OATP1B3, OCT2
P-gp, BCRP, OAT3, OATP1B1, OATP1B3
BCRP, OAT1, OAT3 OCT2, MATE1, MATE2-K, P-gp,
BCRP
Key criteria: Drugs and dose levels selected must be available in various countries
Inhibitory effect of cocktail drugs on transporters Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
• IC50 values primarily obtained from literature, with the exception of furosemide
• IC50 values generally high see next slide for DDI calculations
In vitro inhibitory effect, IC50 (μM)
P-gp BCRP OAT1 OAT3 OATP1B1 OATP1B3 OCT2 MATE1 MATE2-K
Digoxin 125 >30 >30 >30 7.9-47 1-42 >30 >30 >30
Furosemide >2,000 170 5.1-20 1.7-51 30-300 >300 >300 >300 >300
Rosuvastatin >400 140 >100 26 0.047-2.43 3.61 >100 >100 >100
Metformin >30,000 >30,000 >1,000 >1,000 >1,000 >1,000 289-1,700 667 6,500
Potential for mutual DDI Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
• DDI likelihood calculated based on thresholds currently listed in FDA, EMA, and PMDA guidelines
In vivo concentration at DDI site (plasma or GI tract) DDI
Likelihood Dose
(mg)
[I]1,total
(µM)
[I]1,unbound
(µM)
[I]in,max,u
(µM)
[I]2
(µM)
Digoxin 0.25 0.0026 0.00195 0.018 1.28 remote
Furosemide 5 0.42, 0.64 0.017, 0.026 0.058, 0.068 60.5 remote
Rosuvastatin 10 0.0095 0.0011 0.0061-0.010 80.0 remote
Metformin 500 10 10 267 15,500 remote
Furosemide as substrate of P-gp, BCRP, and MRP2 Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
Papp and efflux ratios of furosemide (10 µM) in Caco-2 cells in the absence and presence of transporter inhibitors (n = 3 ± SD). • ZSQ (1 μM, P-gp) • FTC (1 μM, BCRP) • MK-571 (50 μM, MRP) • ZSQ, FTC, and MK571
Control+ZSQ
+FTC
+ZSQ/FTC
+ZSQ/FTC/MK571Furo
sem
ide
Papp
(x10
-6 c
m/s
ec)
0
5
10
15
20
25
AtoBBtoA
33 28 16 17 0.80
Furosemide is a substrate of OAT1 and OAT3 Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
Uptake of furosemide (20 μM) into HEK293 cells expressing OAT1, OAT3, OATP1B1, OATP1B3, and OCT2 (n = 3 ± SD) *: p <0.05.
Time (min)0 2 4 6 8 10
Upta
ke o
f Fur
osem
ide (
L/m
g)
0
10
20
30
40
50
60
70VectorOAT1OAT3OCT2OATP1B1OATP1B3
*
*
**
***
*
Time (min)0 2 4 6 8 10
Upta
ke o
f Fur
osem
ide (
L/m
g)
0
1
2
3
4
*
**
*
***
**
(A)
(A’)
Furosemide interaction with MATE1 and MATE2-K Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
Uptake of furosemide (20 μM) into HEK293 cells expressing MATE1 or MATE2-K (n=3 ± SD) *: p <0.05
Time (min)0 2 4 6 8 10
Uptak
e of F
uros
emide
( L/m
g)
0
1
2
3
4VectorMATE1MATE2-K
(B)
Conclusions from literature and in vitro studies Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., 104:3220-3228
• Mutual DDI upon oral administration of the four selected drugs is unlikely to occur • Digoxin • Furosemide • Metformin • Rosuvastatin
• Based on literature and in vitro data, this 4-component probe drug cocktail is proposed for clinical validation trials
• Proposed low doses of probe drugs expected to be clinically safe • Suitable dose strengths are readily available (globally)
Trial 1: Evaluate drug probes for mutual interaction Open-label, randomized, single-dose, 6-period crossover design (n=24)
Reference Treatments A-D (single doses): • A: 0.25 mg digoxin, 1 tablet • B: 5 mg furosemide, oral solution (0.5 mL) • C: 500 mg metformin HCl, 1 film-coated tablet • D: 10 mg rosuvastatin, 1 film-coated tablet Test Treatments E-G (dosed together): Treatment E (Test 1) Reference Doses • 0.25 mg digoxin • 5 mg furosemide oral solution • 500 mg metformin HCl • 10 mg rosuvastatin, 1 tablet
Treatment F (Test 2) • 0.25 mg digoxin • 5 mg furosemide oral solution • 1000 mg metformin HCl (2 x
500 mg film-coated tablets) • 10 mg rosuvastatin
Treatment G (Test 3) • 0.25 mg digoxin • 20 mg furosemide oral
solution (2.0 mL) • 500 mg metformin HCl • 10 mg rosuvastatin
Stopfer P. et al. (2016) Pharmacokinetic Evaluation of a Drug Transporter Cocktail Consisting of Digoxin, Furosemide, Metformin, and Rosuvastatin. Clin. Pharmacol. Ther. 100(3):259-67
Digoxin: gMean plasma concentration time profiles
Metformin: gMean plasma concentration time profiles
Furosemide: gMean plasma concentration time profiles
Furosemide alone
Furosemide: ANOVA (primary endpoints Cmax and AUC0-tz)
N
Adjusted gMean ratio of Cmax [%]
90% CI [%] N
Adjusted gMean ratio of
AUC0-tz [%]
90% CI [%]
Test Cocktail 1 / Furosemide (Reference)
22/22 80.87 71.51 – 91.47 22/22 96.24 88.61 –
104.53
Test Cocktail 2 / Furosemide (Reference)
11/22 79.64 67.68 – 93.72 11/22 101.22 87.85 –
116.62
Test cocktail 1: Standard cocktail (E) Test cocktail 2: Cocktail with 1000 mg metformin (F)
Rosuvastatin: gMean plasma concentration time profiles
Rosuvastatin alone
Rosuvastatin in test cocktails
Rosuvastatin: ANOVA (primary endpoints Cmax and AUC0-tz)
N Adjusted
gMean ratio of Cmax [%]
90% CI [%] N
Adjusted gMean ratio of AUC0-tz [%]
90% CI [%]
Test Cocktail 1 / Rosuvastatin (Reference)
23/22 138.56 122.47 – 156.75 23/22 143.37 128.09 –
160.47
Test Cocktail 2 / Rosuvastatin (Reference)
11/22 133.68 103.79 – 172.156 11/22 148.68 113.23 –
195.25
Test Cocktail 3 / Rosuvastatin (Reference)
12/22 140.05 124.11 – 161.57 12/22 146.72 124.96 –
172.28
Test cocktail 1: Standard cocktail (E) Test cocktail 2: Cocktail with 1000 mg metformin (F) Test cocktail 3: Cocktail with 20 mg furosemide (G)
Trial 2: Adjust doses to optimize cocktail design Open-label, randomized, single-dose, 6-period crossover design (n=18)
Goal: Identify source of interaction with RSV in initial cocktail study due to coadministration of metformin or furosemide? Treatments (single doses): • All: 10 mg RSV reference treatment, film-coated tablet • T1: 10 mg RSV + 10 mg metformin (0.1 mL metformin HCl) • T2: 10 mg RSV + 50 mg metformin (0.5 mL metformin HCl) • T3: 10 mg RSV + 500 mg metformin (5 mL metformin HCl) • T4: 10 mg RSV + 1 mg furosemide (0.1 mL) • T5: 10 mg RSV + 5 mg furosemide (0.5 mL)
Subjects fasted overnight (10+ hr), doses administered with 240 mL water; continued fasting/standing 4 hr post-dosing
Rosuvastatin + metformin or furosemide ANOVA data (primary endpoints Cmax and AUC0-tz)
N Adjusted
gMean ratio of Cmax [%]
90% CI [%] N
Adjusted gMean ratio of AUC0-tz [%]
90% CI [%]
T1: RSV + 10 mg metformin 15-16 102.47 87.19 –
120.42 15-16 101.95 89.49 – 116.15
T2: RSV + 50 mg metformin 16 106.98 92.54 –
123.69 16 106.09 96.12 – 117.11
T3: RSV + 500 mg metformin 15-16 154.07 131.70 –
180.24 15-16 152.18 135.12 – 171.41
T4: RSV + 1 mg furosemide 15-16 106.81 91.78 –
124.30 15-16 106.97 94.34 – 121.30
T5: RSV + 5 mg furosemide 16 117.98 98.27 –
141.65 16 115.92 101.93 – 131.82
RSV + metformin: gMean plasma conc. time profiles
T ime [hours]
0 12 24 36 48
Rosu
vast
atin
pla
sma
conc
entra
tion
[nm
ol/L
]
0.1
1
10
100 Rosuvastatin (N=16)Rosuvastatin + 10 mg Metformin (T1) (N=15)Rosuvastatin + 50 mg Metformin (T2) (N=16)Rosuvastatin + 500 mg Metformin (T3) (N=15)
b
Rosuvastatin + Metformin (500 mg)
RSV + furosemide: gMean plasma conc. time profiles
b
T ime [hours]
0 12 24 36 48
Rosu
vast
atin
pla
sma
conc
entra
tion
[nm
ol/L
]
0.1
1
10
100Rosuvastatin (N=16)Rosuvastatin + 1 mg Furosemide (T4) (N=15)Rosuvastatin + 5 mg Furosemide (T5) (N=16)
Rosuvastatin + Furosemide (5 mg)
Conclusions
• Use of a probe drug cocktail is a promising approach to reduce the number of clinical studies required to investigate transporter-mediated DDIs
• Trial 1: Increased RSV exposure likely attributable primarily to coadministration with metformin, and to a minor degree furosemide
• Trial 2: Increased RSV exposure when coadministered with 500 mg metformin (slightly with 5 mg furosemide); DDI eliminated by reducing the dose of metformin to 10 or 50 mg, reducing the dose of furosemide to 1 mg
• Interaction mechanism: Not predictable from in vitro transporter data; possibly due to an effect on absorption? More studies needed.
• Overall assessment: A four-component drug transporter cocktail should be further evaluated using 0.25 mg digoxin, 1 mg furosemide (previously 5 mg), 10 or 50 mg metformin (previously 500 mg) and 10 mg RSV
• Future plans: Coadministration of the cocktail with known transporter inhibitors
Acknowledgments
Core team and sponsors: • Thomas Ebner
• Dietmar Gansser
• Florian Gantner
• Thomas Giessmann
• James Hilbert
• Kathrin Hohl
• Naoki Ishiguro
• Arvid Jungnik
• Fabian Muller
• Ashish Sharma
• Peter Stopfer
• Heike Zimdahl-Gelling
• Donald Tweedie
• Mark Castles
• Ulrich Roth 29
Internal contributors: • Ayano Fukuhara
• Caroline MacLean
• Christian Lechner
• Meeghan O’Connor
• Naoko Ohtsu
• Lalitha Podila
• Asami Saito
• Hidetada Shimizu
• Junichi Takano
• Masahito Takatani
• Tokuko Takatsuka
• Ikumi Washio
• Walter Weber
External contributors:
• Uwe Fuhr
• Martin Fromm
• Kathleen Giacomini
• Richard Kim
• Mikko Niemi
• Peter Swaan
Backups
In vitro mechanistic studies cause of RSV change?
• Contribution of NTCP to RSV uptake, potential inhibition by cocktail components?
• Influence of allelic variants of OATP1B1 on results?
• Other uptake transporters contributing to RSV clearance, and the effects of cocktail components?
• Potential for inhibition of intestinal BCRP by cocktail components? • Need to recheck inhibition of BCRP by furosemide
• Possibility that cocktail components inhibited intestinal and/or hepatic metabolism of RSV? • Evaluate UGTs and CYP2C9
31
Key observations from Trial 1 Stopfer P. et al. (2016) CPT, 100(3):259-67
• Digoxin, metformin, and furosemide AUC0-tz were similar when dosed individually and as a cocktail
• Digoxin and metformin Cmax were similar when dosed individually and as a cocktail
Notable changes when administered as a cocktail:
• Cmax of furosemide was reduced by 19.1%
• Cmax of rosuvastatin increased by 38.6%
• AUC0-tz of rosuvastatin increased by 43.4%
Digoxin: ANOVA (primary endpoints Cmax and AUC0-tz)
N
Adjusted gMean ratio of Cmax [%]
90% CI [%] N
Adjusted gMean ratio
of AUC0-tz [%]
90% CI [%]
Test Cocktail 1 / Digoxin (Reference)
22 /22 100.51 89.61 – 112.73 22 / 22 107.32 95.41 – 120.717
Test Cocktail 2 / Digoxin (Reference)
11/22 96.50 75.21 – 123.83 11/22 102.26 82.21 – 127.18
Test Cocktail 3 / Digoxin (Reference)
11/22 90.16 78.24 – 103.90 12/22 82.61 73.33 – 100.76
Test cocktail 1: Standard cocktail (E) Test cocktail 2: Cocktail with 1000 mg metformin (F) Test cocktail 3: Cocktail with 20 mg furosemide (G)
Metformin: ANOVA (primary endpoints Cmax and AUC0-tz)
N
Adjusted gMean ratio
of Cmax [%]
90% CI [%] N
Adjusted gMean ratio
of AUC0-tz [%]
90% CI [%]
Test Cocktail 1 / Metformin (Reference)
23/22 106.95 97.65 – 117.12 23/22 99.44 93.40 – 105.88
Test Cocktail 3 / Metformin (Reference)
12/22 113.48 91.98.67 – 140.00 12/22 107.76 93.28 – 124.49
Test cocktail 1: Standard cocktail (E) Test cocktail 2: Cocktail with 1000 mg metformin (F) Test cocktail 3: Cocktail with 20 mg furosemide (G)
RSV + metformin: gMean plasma concentration time profiles
T ime [hours]
0 12 24 36 48
Rosu
vast
atin
pla
sma
conc
entra
tion
[nm
ol/L
]
0.1
1
10
100 Rosuvastatin (N=16)Rosuvastatin + 10 mg Metformin (T1) (N=15)Rosuvastatin + 50 mg Metformin (T2) (N=16)Rosuvastatin + 500 mg Metformin (T3) (N=15)
b
Rosuvastatin + Metformin (500 mg)
Rosuvastatin + Metformin (500 mg)
RSV + furosemide: gMean plasma conc. time profiles
a
T ime [hours]
0 12 24 36 48
Rosu
vast
atin
pla
sma
conc
entra
tion
[nm
ol/L
]
0
2
4
6
8
10
12
Rosuvastatin (N=16)Rosuvastatin + 1 mg Furosemide (T4) (N=15)Rosuvastatin + 5 mg Furosemide (T5) (N=16)
b
T ime [hours]
0 12 24 36 48
Rosu
vast
atin
pla
sma
conc
entra
tion
[nm
ol/L
]
0.1
1
10
100Rosuvastatin (N=16)Rosuvastatin + 1 mg Furosemide (T4) (N=15)Rosuvastatin + 5 mg Furosemide (T5) (N=16)
Rosuvastatin + Furosemide (5 mg)
Rosuvastatin + Furosemide (5 mg)
Clinical DDI studies with RSV + inhibitors Source: University of Washington DDI Database
37
Incr
ea
se in
ro
suva
sta
tin A
UC
an
d C
max
(fo
ld v
s. c
on
tro
l)
c y c los p o r in
e
r ifam
p in
s ime p re
v ir
a taz a n a v ir
a n d r ito
n a v ir
c lop id
o g rel
e ltrom
b o p a g
g emfib
roz il
u rso d e o x y c h o lic
ac id
d a run a v ir
a n d r ito
n a v ir
e lv iteg ra
v ir a n d c
o b ic is tat
itra c o n a z o le
t ipra
n a v ir a n d r i
ton a v ir
lom
itap id
e0
1
2
3
4
6
8
1 0
1 2
A U C
C m ax
Clinical DDI study protocol
Design: Open-label, randomized, single-dose, 6-period crossover (n=24)
Primary endpoints: AUC0-tz and Cmax
Secondary endpoint: AUC0-∞
Additional PK parameters of interest: tmax, λz, t1/2, %AUCtz-∞, MRTpo, CL/F, Vz/F, Aet1-t2, fet1-t2, CLR,t1-t2 Statistical methods: ANOVA
Rosuvastatin fe0-36 OATP1B1 / PGx
Rosuvastatin CLr0-36 OATP1B1 / PGx
Cooperstown cocktail Streetman et al. (2000) CPT, 68:375
41
Influence of OATP1B1 variants on RSV exposure (mean +/- SD)
42
AU
Cla
st (
nm
ol*
h/L
)C
max (n
mo
l/L)
R S V : *1 A a
n d *1B
R S V : *1 B /*1
5 or *
1 B /*5
R S V : *1 5 /*1
5 (n= 1 )
C o c k tail
1 : *1 A a
n d *1B
C o c k tail
1 : *1 B /*1
5 or *
1 B /*5
C o c k tail
1 : *1 5 /*1
5 (n= 1 )
R S V : *1 A a
n d *1B
R S V : *1 B /*1
5 or *
1 B /*5
R S V : *1 5 /*1
5 (n= 1 )
C o c k tail
1 : *1 A a
n d *1B
C o c k tail
1 : *1 B /*1
5 or *
1 B /*5
C o c k tail
1 : *1 5 /*1
5 (n= 1 )
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
0
5
1 0
1 5
2 0
2 5A U C la s t
C m ax
Transporters discussed in the ITC White Paper: Expression and distribution
Transporters are expressed in multiple organs, contribute to the ADME of drugs, metabolites, endobiotics, vitamins, and nutrients Complex system - tissue levels of drugs facilitated or hindered by transporters
Giacomini et al. (2010) 9:215-236
43
Cooperstown and C + 1 cocktail Chainuvati et al. (2003) CPT, 74:473
44
Biomarker Ratios: Cooperstown + 1 Cocktail Study
Mea
n R
atio
(95%
con
fiden
ce in
terv
al)
CYP1A2
NAT2 XO
CYP2C9
CYP2C19
CYP2D6
CYP3A0.0
0.5
1.0
1.5
2.0
caffeine
IV midazolam
dextromethorphan omeperazole
warfarin
Furosemide interaction with OATP1B1 and OATP1B3 Ebner, Taub, Ishiguro (2015) J. Pharm. Sci., online
• Uptake of furosemide into HEK293 cells expressing OATP1B1 or OATP1B3
• Inhibition of OATPs by the inhibitor rifampicin (n = 3 ± SD)
v/S (
L/m
in/m
g pr
otein
)
0
1
2
3
4
5Vector OATP1B1 OATP1B3
20 M 2000 M 20 M +100 M Rif
(C)
Challenges choosing a substrate or inhibitor of BCRP Lee et al. (2015) DMD, 43:490-509
46
Intestine Liver
Bile
Lumen Epithelial cells Blood
Blood
Hepatocytes
passive permeability
Intestinal BCRP inhibition Lee et al. (2015) DMD, 43:490-509
Precipitant I2 (µM) BCRP Parameters
IC50 I2/IC50
lapatinib 5299.42 0.025 211976.80
sulfasalazine 40160.64 0.46 87305.74
curcumin 21716.71 1.6 13572.94
erlotinib 1525.01 0.13 11730.85
elacridar 2838.64 0.31 9156.91
nilotinib 2826.96 1.38 2048.52
gefitinib 2013.83 1.01 1993.89
sunitinib 501.91 0.64 784.23
pantoprazole 370.03 5.5 67.28
rabeprazole 445.12 8.5 52.37
47
substrate
availability/ interactions complications with absorption
cancer therapies
Hepatic BCRP inhibition Lee et al. (2015) DMD, 43:490-509
Precipitant I (µM, Cmax)
BCRP Parameters
IC50 I/IC50
sulfasalazine 79 0.46 171.74
lapatinib 4.2 0.025 168.00
erlotinib 6.06 0.13 46.62
nilotinib 4.3 1.38 3.12
pantoprazole 6.5 5.5 1.18
elacridar 0.327 0.31 1.05
gefitinib 0.8 1.01 0.79
48
Other enzyme/transporter interactions Lack of clinical BCRP inhibition data
Complications with absorption Would need to use a therapeutic dose
Regulatory discussions: Enzymes, transporters, DDIs
1997 1999 2003 2004 2006 2010 2011 2012
FDA In Vitro
DDI Guidance
FDA In Vivo
DDI Guidance
Guidance Publication
Public Workshops
Advisory Committee Meetings
Public Workshops, Comments
FDA Concept
Paper
CYPs P-gp CYP2B6 CYP2C8
Transporters
1st FDA Draft DDI
Guidance
EMA Draft DDI
Guidance
ITC Whit
e Pape
r
2nd FDA Draft DDI
Guidance
ITCW1
ITCW2
EMA Final DDI
Guidance
Cooperstown cocktail studies Streetman et al. (2000) CPT, 68:375 | Chainuvati et al. (2003) CPT, 74:473
50
Transporter studies: Tools available at BI
Initial transporter
profiling studies
Mechanistic studies: • Indication-specific • Clearance-specific • Project data
Transfected cells Caco-2
SCHH HepatoPac Inverted membrane vesicles
Isolated perfused rat liver/lung
Bidirectional transport studies: Caco-2, MDCK-MDR1
BL to AP Papp Secretory Transport
AP to BL Papp Absorptive Transport
BL-AP / AP-BL ~1 Not an Efflux Pump Substrate BL-AP / AP-BL >2 Efflux Pump Substrate
Classification of membrane transport
Membrane Transport
Passive transport 1. Simple diffusion 2. Facilitated diffusion
Active transport 3. Primary active
transport 4. Secondary active
transport –Symport / Antiport
Concentration gradient
Transported molecule
1 2 2 3 4 4
Channel Transporter Transporter Transporter Transporter
ATP AMP
Carrier-mediated
Clinical DDI studies: Few selective transporter substrates or inhibitors available
Transporter Substrates Inhibitors
ITC White Paper
Selectivity? ITC White Paper
Selectivity?
P-gp Digoxin P-gp, OATP4C1, sodium-dependent transporter (new)
Cyclosporine A P-gp, OATP, and other transporters/enzymes
BCRP Sulfasalazine Pitavastatin Ciprofloxacin Rosuvastatin
Metabolism also occurs; possibly substrates of other transporters
No inhibitor recommended
Not applicable
OATP1B1 Atorvastatin Pitavastatin Rosuvastatin
Multiple transporters
Rifampicin Cyclosporine A
P-gp, OATP, and other transporters/enzymes
OATP1B3 Telmisartan Multiple transporters
OAT1 Many drugs recommended
Not selective for OAT1 Probenecid OATs and OATPs
OAT3 Not selective for OAT3
OCT2 Metformin OCTs and MATE Cimetidine OCTs and MATE
A case-by-case approach, based on in vitro transporter and metabolism data, is essential for selecting in vivo probe
substrate/inhibitor for clinical DDI studies
abcd Clinical study: P-gp mediated DDI involving digoxin and rifampicin
Digoxin PO dose Digoxin IV dose
- RIF
+ RIF 3.5x ↑
Greiner et al., JCI (1999) 104:147
Rosuvastatin dose adjustment
0 2 4 6 8 10 12
Atazanavir / ritonavir
Lopinavir / ritonavir
Gemfibrozil
Cyclosporine A
Fold adjustment from top marketed doseFold change in AUC or Cmax
Fold Change
Source: FDA labels, presented by Joe Polli (GSK) at 2011 ISSX Meeting and 2012 ITCW2 Meeting
Dose adjustments tend to follow the fold change in AUC and/or Cmax
Theoretical maximum statin AUC increase: TPs/DMEs Elsby et al (2012) CPT, 92(5):584-598
ITC Commentary: Clinically Important Transporter Polymorphisms Giacomini et al (2013) CPT, 94(1):23-26
(1) In vitro studies (2) Clinical DDI study? (3) Consider PGx variants (4) Collect DNA samples, SNP analysis (5) Relate SNPs with data (6) Multiscale analysis – DME, TP, age, race, sex, etc.
Complex DDIs involving transporters and DMEs (CsA) Elsby et al (2012) CPT, 92(5):584-598
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• SMV: Hepatic CYP3A4 DDI unlikely (passive uptake) intestinal CYP3A4/OATP1B1 inhibition
• ATV: Inhibition of intestinal BCRP and CYP3A4, OATP1B1; passive uptake low (<1 5%)
Complex DDIs involving transporters and DMEs (CsA) Elsby et al (2012) CPT, 92(5):584-598
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• PTV: OATP1B1 and OATP1B3 • PRV: OATP1B1 and intestinal efflux transporter – possibly MRP2? • RSV: Intestinal BCRP; active hepatic uptake facilitated by OATP1B1/1B3 and
NTCP
Complex DDIs involving transporters and DMEs Elsby et al (2012) CPT, 92(5):584-598
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