the resurrection of ezetimibe: a story of perseverance · 1 the resurrection of ezetimibe: a story...

1

The Resurrection of Ezetimibe:

A Story of Perseverance

Harry “Chip” Davis

CVPath Institute

Gaithersburg, MD

(Schering-Plough / Merck)

Ezetimibe Inhibits Intestinal

Cholesterol Uptake and Absorption(Discovered in mid 1990s by in-vivo cholesterol absorption screening)

1000 mg

Transporter or Passive Diffusion ?

Ezetimibe ?

MTPABCG5/G8

Ezetimibe and its glucuronide metabolite are potent inhibitors of

dietary and biliary cholesterol absorption

Ezetimibe and Its Glucuronidated Metabolite (SCH 60663)

Glucuronidation

SCH 60663

(Glucuronide)

Ezetimibe

NO

OH

O

F

F

O

CO2H

OHHO

OH

NO

OH

OH

F

F

UGT1A1,

UGT1A3,

UGT2B15

Reduction of Cholesterol Absorption in

Humans With Ezetimibe

(10mg per day 2 week crossover study)

*P<0.001

49.8%*

22.7%

0

10

20

30

40

50%

Fra

cti

on

al

Ch

ole

ste

rol A

bso

rpti

on

(Geo

metr

ic M

ean

)

EzetimibePlacebo

Ezetimibe Inhibited Cholesterol Absorption by 54%

54%

Ezetimibe had No Target Organ Toxicity in Mice, Rats, and Dogs and

No Evidence for Carcinogenicity in 2-Year Oncogenicity Studies in Mice and Rats

(Halleck, Davis et al. Toxicology 258: 116-130, 2009)

Mean

% c

han

ge in

LD

L

fro

m b

aselin

e a

t w

k12

Placebo

(n=52)

-30

-20

-10

0

+10Ezetimibe

0.25 mg

(n=47)

Ezetimibe

1 mg

(n=49)

Ezetimibe

5 mg

(n=49)

Ezetimibe

10 mg

(n=46)

-9.9

* -12.6

*-16.4 *

-18.7 *

+4.3

Ezetimibe Monotherapy (Approved 2002)

Maximal Efficacy at 10 mg/day

Phase IIb Monotherapy Dose-Response Study:

LDL-C Reduction at Week 12

Bays et al. Clin.Ther. 2001;23:1209-1230.* p<.01 vs placebo

Ezetimibe Prevents Diet-Induced Hypercholesterolemia in Monkeys:

Why doesn’t ezetimibe reduce plasma cholesterol below baseline

levels? Compensatory increase in cholesterol synthesis.

Ezetimibe (0.1 mg/kg/d)

Time (days)

Control

403020100

100

150

200

250

300

Pla

sma C

hole

ster

ol

(mg/d

L)

Crossover

350

van Heek, Davis et al. Eur J Pharm. 2001; 415:79-84

8

Ezetimibe + Lovastatin Lowers Plasma Cholesterol

in Chow-Fed Dogs in a Synergistic Manner

Control (n=5)

Ezetimibe, 0.007 mg/kg (n=5)

Lovastatin, 5 mg/kg (n=5)

Combination (n=5)

1614121086420-2-80

-60

-40

-20

0

20

40

Days of Treatment

Ch

an

ge

in P

lasm

a C

hole

ster

ol

(mg/d

L)

133±17

137±16

136±9

136±12

Davis, Watkins, et al. Metabolism 2001; 50: 1234-1241

9

Dual Inhibition of Cholesterol

Synthesis and Absorption

Bileacids

Synthesis

Atherogenic

lipoproteins

Small

intestine

Excretion in

feces

Bile

Absorption

Liver

Diet

Statin

Cholesterol

Ezetimibe

10

Ezetimibe Combined with Simvastatin (Vytorin / Inegy Approved

2004) Reduces LDL Cholesterol and C-Reactive Protein

Pearson T et al, Am J Cardiol 99: 1706 , 2007

LDL-Cholesterol CRP

Ezetimibe: Clinical Summary

Selective intestinal cholesterol (10 mg average 54% to 65%

reduction) and phytosterol absorption inhibitor (no effect on fat

soluble vitamins, triglycerides, etc)

Maximally effective dose is 10 mg once a day for

hypercholesterolemia and sitosterolemia

Extremely low systemic plasma levels (Cmax 0.021 uM),

circulates enterohepatically, repeatedly delivering the agent

back to the site of action (glucuronide metabolite 88% of total

plasma drug concentration)

LDL-C reduction 18% as monotherapy, and incremental 18-

25% additional reduction with statin co-administration

Plasma phytosterol levels reduced approximately 50% in

patients with sitosterolemia or hypercholesterolemia

Molecular Target of Ezetimibe (Zetia, Ezetrol)?

Intestinal Localization 125I-Gluc-Ezetimibe in Rats

Genomic/ Bioinformatic Strategy to Identify the

Molecular Target of Ezetimibe

All known sterol processing mechanisms, as well as biochemical and

molecular approaches were evaluated for more than 12 years. All identified

proteins were not involved in the mechanism of action of Ezetimibe.

Genomic/ Bioinformatic Strategy Hypothetical properties of an ideal candidate cholesterol transporter:

Will be expressed in enterocytes in the proximal small intestine

– restricted tissue expression

Membrane bound protein expressed on the surface of the cell

Contain features found in proteins involved in sterol metabolism e.g.

cholesterol regulated expression, sterol sensing domain

Created and sequenced a rat small intestine DNA library of > 16,000 genes

Using bioinformatics these sequences were assembled and human and mouse

databases mined for the properties of the ideal cholesterol transporter

Niemann-Pick C1 Like 1 Protein Is

Critical for Intestinal Cholesterol

Absorption

Scott W. Altmann,* Harry R. Davis, Jr., Li-ji

Zhu, Xiaorui Yao, Lizbeth M. Hoos, Glen

Tetzloff, Sai Prasad N. Iyer, Maureen Maguire,

Andrei Golovko, Ming Zeng, Luquan Wang,

Nicholas Murgolo, Michael P. Graziano

Dietary cholesterol consumption and intestinal

cholesterol absorption contribute to plasma

cholesterol levels, a risk factor for coronary heart

disease. The molecular mechanism of sterol

uptake from the lumen of the small intestine is

poorly defined. We show that Niemann-Pick

C1Like 1(NPC1L1) protein plays a critical role in

the absorption of intestinal cholesterol. NPC1L1

expression is enriched in the small intestine and

is in the brush border membrane of enterocytes.

Although otherwise phenotypically normal,

NPC1L1-deficient mice exhibit a substantial

reduction in absorbed cholesterol, which is

unaffected by dietary supplementation of bile

acids. Ezetimibe, a drug that inhibits cholesterol

absorption, had no effect in NPC1L1 knockout

mice, suggesting that NPC1L1 resides in an

ezetimibe-sensitive pathway responsible for

intestinal cholesterol absorption.

Science 303: 1201-1204, Feb 20, 2004

I647N

Ezetimibe Binding Site

Coding SNPs (Red)

Loop with Sterol Binding Pocket

Human NPC1L1

Davis HR et al Current Opinion in Lipidology 22:467-478, 2011

Ezetimibe Prevents the Internalization of NPC1L1

and Uptake of Free Cholesterol In-Vivo

Xie C, Song B-L, et al J Lipid Res 53:2092, 2012

Model of NPC1L1/Cholesterol Uptake(P-S Li, B-L Song, et al Nature Medicine 20:80-86, 2014)

AZD4121

[45]

AstraZeneca Human

recombinant?=0.065

Mouse=0.08 uM/kg/? Phase III

Discontinued,

LDL-C <-10% @

12mg

Canosimibe

(AVE5530)

[46]

Sanofi-aventis NA Hamster=Slightly more

potent than ezetimibe

Phase III, 12

weeks

Discontinued

LDL-C -14.5% @

25 mg

KT6-971[47] Kotobuki

Pharmaceutical

Human

recombinant=0.99

Hamster=0.23 mg/kg/7d

Phase I

discontinued

MD-0727 †

[48]

Microbia

pharmaceuticals

NA Rat=68%@0.3mg/kg/3h

Mouse=76%@3mg/kg/

3h

Hamster=88%@1mg/kg

/4h

Phase I

discontinued

MK-6213

[49]

Merck Human recombinant

=0.005

Mouse=28ug/kg/5h

Rat =3.3ug/kg/16h

Hamster=68ug/kg/7d

Phase 2

Discontinued,

LDL-C -

13.3%@160mg

†Definitive structure was not available for MD-0727. Patents reference novel quaternary salt

derivatives (A) and tethered dimers and trimers of 1,4 diphenylacetidin-2-ones (B).

NO

OH

F

O

OHHO

OHHO

NO

OH

F

O CH3

HN

O

NH

O

OH

OH

OH

OH

OH

NO

S

OH

F

O NH

HN

F

O

O

OH

O

NO

OH

F

OH

HN

SCH3

O O

OHOH

(A)(A)

(B)(B)

Intestinal Specific Cholesterol Absorption Inhibitors


Ezetimibe 307nM

Ez-Gluc 150nM

Hepatic Human NPC1L1 Transgenic Mice have Reduced

Biliary Cholesterol and Increased Plasma Cholesterol,

which is Normalized by Ezetimibe

Temel et al, JCI 117:1968, 2007

Bile

Atheroma

LiverIntestine

CholesterolPool (Micelles)

25%Dietary Chol

Bile Acids

FreeChol

↑ Fecalsterols

Remnantreceptors

Hepatic

ApoB-100

Intestinal Apo

B-48

LDLR

75%

Biliary chol

Cholesterol Pool

CMRCM

VLDL

VLDL-R/lDL

LDL

Blood

Peripheral

Tissues

TG

TG

Lipases

Lipases

TG

TG

CE

CETP

TG

CETP

TG

CE

HDL (mature)

SR-BI

LCAT

HDL (nascent)

Cholesterol andplant sterols

Cholesterol andplant sterols

Acetyl CoA

Chol

HMGCoA

RedStatin

ABCG5/G8

NPC1L1Ezetimibe

Enterocyte

ABCG5/G8

NPC1L1 Chol

ester

Free

Chol

ACAT

Acetyl CoA

MTP

HMGCoA

Red

Statin

Ezetimibe

macrophage


BY BLOCKING CHOLESTEROL UPTAKE IN THE LIVER AND INTESTINE,

EZETIMIBE FOSTERS GREATER ELIMINATION OF FREE CHOLESTEROL

Ezetimibe Inhibits Atherosclerosis in

Animal Models of Atherosclerosis

Davis HR, et al. Atherosclerosis 2011;215:266-278.

Davis HR et al ATVB 27:841-849, 2007 and Unpublished

ApoE null 8 month old Npc1l1/ApoE null 2 year old

Innominate Arteries of 8 month old apoE null and 2 year

old Npc1l1/apoE null Male Mice Fed a Chow Diet

- 78%

The Myocardial Infarction Genetics Consortium Investigators. N Engl J Med 2014;371:2072-2082

Naturally occurring mutations that disrupt NPC1L1 function were found to be associated with reduced plasma LDL cholesterol levels (12mg/dl) and a reduced risk of coronary heart disease (53%) (heterozygous).

Inactivating Mutations in NPC1L1 and Protection from Coronary Heart Disease

Sekar Kathiresan

Ezetimibe/Simvastatin Surrogate and Clinical Outcome Program

Trial Population Endpoint Treatment

ENHANCE:

Started: 6/02HeFH

(n = 720)Carotid IMT

EZE/Simva 10/80

vs

Simva 80

SEAS

Started: 3/03Aortic Stenosis

(n = 1873)MACE

EZE/Simva 10/40

vs

PBO

SHARP

Started: 7/03CKD

(n = 9438)MACE

EZE/Simva 10/20

vs

PBO vs Simva 20

IMPROVE-IT

Started: 10/05

End: 2014

ACS

(n = 18,000)MACE

EZE/Simva 10/40

vs

Simva 40

Months

ENHANCE: LDL-cholesterol (HeFH)

ENHANCE

SimvaEze-Simva

-40

0 6 12 18 24

-50-60-70

0

-10-20-30

10

Pe

rce

nta

ge c

han

ge f

rom

bas

elin

e

P<0.01

-16.5 % incremental reduction

Baseline (mg/dL)

24 months (mg/dL)

Simva 318 ± 66 193 ± 60

Eze-Simva 319 ± 65 141 ± 53

ENHANCE: Critical Factors for Successful cIMT Trial

regression

progression

regression

progression

cIM

T m

m

years0 1 2

0.80

0.85

0.75

0.90

0.95

0.70

0.65

ASAP - 1997

ENHANCE - 2003

ENHANCE

Simva LDLc -40%

Simva/Eze LDLc -57%

ASAP

Simva LDLc -40%

Atorva LDLc -52%

P= ns

Simva No progress;

Sim/Eze No regress

FAILURE?

Stein: ENHANCE – failed drug or failed trial

SEAS Trial LDL-Cholesterol

Intention to Treat Population

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5

Year

0

25

50

75

100

125

150

Me

an

(m

g/d

L)

EZ/Simva 10/40 mg

Placebo

28

Ischemic Cardiovascular Events

(ICE) Outcome in SEAS

PlaceboE/S# patients at risk

917 898

867 838

823 788

769 729

76 76

Intent-to-Treat Population

Pati

en

ts (

%)

wit

h F

irst

Even

t

Years in Study

Hazard ratio: 0.78, P = 0.024E/S (10/40 mg)

Placebo

0 1 2 3 4 50

10

20

30

Rossebø AB et al. N Engl J Med. 2008;359:1343-1356.

In-Depth Assessment of Cancer Data

“In conclusion, the non-clinical data do

not support the proposed hypothesis

based on the single observation from

the SEAS trial and, rather, support the

conclusion that ezetimibe does not

represent a carcinogenic hazard to

humans using this drug in a therapeutic

setting."

An Assessment Of The Carcinogenic

Potential Of Ezetimibe Using Nonclinical

Data In A Weight-of-evidence Approach

M. Halleck, H.R. Davis,P. Kirschmeier,D.Levitan,

R.D. Snyder, K. Treinen and J.S. MacDonald

Toxicology 258: 116-130, 2009

30

The SHARP StudyStudy of Heart and Renal Protection

VYTORIN® (ezetimibe/simvastatin) and ZETIA®

(ezetimibe) in Patientswith Chronic Kidney Disease

Baigent C. et al. Lancet 377:2181-2192, 2011

SHARP was designed and implemented by the

Clinical Trial Service Unit (CTSU) at the University of Oxford

SHARP TrialEffect on LDL-cholesterol (LDL-C) at 1 year of

three-quarters compliance with eze/simva

SHARP Collaborative Group Am Heart J 2010

-13

-29

-42

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

eze/simva vs simva simva vs placebo eze/simva vs placebo

LDL-

C d

iffe

ren

ce (

mg

/dL)

0 1 2 3 4 5

Years of follow-up

0

5

10

15

20

25

Pro

po

rtio

n s

uff

erin

g ev

ent

(%)

Risk ratio 0.83 (0.74-0.94) Logrank 2P=0.0021 placebo

eze/simva

SHARP (Study of Heart and Renal Protection)

Key outcome: Major Atherosclerotic Events

Baigent C. et al. Lancet 377:2181-2192, 2011

IMProved Reduction of Outcomes: Vytorin Efficacy International Trial

A Multicenter, Double-Blind, Randomized Study to Establish the

Clinical Benefit and Safety of Vytorin (Ezetimibe/Simvastatin Tablet) vs

Simvastatin Monotherapy in High-Risk Subjects Presenting

With Acute Coronary Syndrome

Patients stabilized post ACS ≤ 10 days:LDL-C 50–125*mg/dL (or 50–100**mg/dL if prior lipid-lowering Rx)

Standard Medical & Interventional Therapy

Ezetimibe / Simvastatin

10 / 40 mg

Simvastatin

40 mg

Follow-up Visit Day 30, every 4 months

Duration: Minimum 2 ½-year follow-up (at least 5250 events)

Primary Endpoint: CV death, MI, hospital admission for UA,

coronary revascularization (≥ 30 days after randomization), or stroke

N=18,144

Uptitrated to

Simva 80 mg

if LDL-C > 79

(adapted per

FDA label 2011)

Study Design

*3.2mM

**2.6mM

Cannon CP AHJ 2008;156:826-32; Califf RM NEJM 2009;361:712-7; Blazing MA AHJ 2014;168:205-12

90% power to detect

~9% difference

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Milestones and Events

ENHANCE

Study Results

(Jan-2008)

75% Interim

Analysis

Mar-2012

DSMB

Review (88%)

Mar-2013

Database Lock

Oct-2014

LPI

08-Jul-2010

50% Interim

Analysis

Mar-2010

ARBITER-6

(Nov-2009)

FDA Simva Label

Change 80mg dose

(Jun-2011)

5250

Events

SEAS Study Results

(Jul-2008)

FPI

26-Oct-2005

Sep 2007: increase

n=12,500 and events

to 5250, cap STEMI

April

2008:

increase

n=18,000

Study Metrics

Simva

(N=9077)

EZ/Simva

(N=9067)

Uptitration to Simva 80mg, % 27 6

Premature study drug D/C, % 42 42

Median follow-up, yrs 6.0 5.9

Withdraw consent w/o vital status, %/yr 0.6 0.6

Lost to follow-up, %/yr 0.10 0.09

Follow up for primary endpoint, % 91 91

Follow up for survival, % 97 97

Total primary endpoint events = 5314

Total patient-years clinical follow-up = 97,822

Total patient-years follow-up for survival = 104,135

438 — Drug never taken

Participant Disposition for1 Endpoint — OT Population

Off drug — censored @ 30 daysCompleted on drug*

80,286 patient years follow up for primary endpoint in ITT

ITT:

18,144(5314 1 EPs*)

n = 7133

S

3574

EZ/S

3559

2 yrs.

OT:

17,706

n = 10,573

S

5281

EZ/S

5292

4.4 yrs.

= 60,298 total patient-years of F/U OT

Mean years of

F/U on drug for

primary endpoint

*1 event on drug (4011) or

non-CV death on drug or

full assessment on drug

during closeout

Followed

off drug(1303 1 ITT

EPs* occurred >

30d off drug)

*EPs = endpoints

Baseline Characteristics

Simvastatin

(N=9077)

%

EZ/Simva

(N=9067)

%

Age (years) 64 64

Female 24 25

Diabetes 27 27

MI prior to index ACS 21 21

STEMI / NSTEMI / UA 29 / 47 / 24 29 / 47 / 24

Days post ACS to rand (IQR) 5 (3, 8) 5 (3, 8)

Cath / PCI for ACS event 88 / 70 88 / 70

Prior lipid Rx 35 36

LDL-C at ACS event (mg/dL, IQR) 95 (79, 110) 95 (79,110)

LDL-C and Lipid Changes

1 Yr Mean LDL-C TC TG HDL hsCRP

Simva 69.9 145.1 137.1 48.1 3.8

EZ/Simva 53.2 125.8 120.4 48.7 3.3

Δ in mg/dL -16.7 -19.3 -16.7 +0.6 -0.5

Median Time avg

69.5 vs. 53.7 mg/dL

Mean LDL-C at 1 Year OT & ITT

Simva OT LDLC 69.5 mg/dL Simva ITT LDLC 69.9 mg/dL

LDLC values at 1 year

ITT

OT

ITT

OT

EZ/Simva OT LDLC 52.5 mg/dL EZ/Simva ITT LDLC 53.2 mg/dL

OT LDLC 17.0 mg/dL ITT LDLC 16.7 mg/dL

EZ/Simva

Simva

Primary Endpoint — ITT

Simva — 34.7%

2742 events

EZ/Simva — 32.7%

2572 events

HR 0.936 CI (0.887, 0.988)

p=0.016

Cardiovascular death, MI, documented unstable angina requiring

rehospitalization, coronary revascularization (≥30 days), or stroke

7-year event rates

NNT= 50

6.4% Treatment effect

Reaffirms the LDL-C hypothesis

Primary Endpoint On-Treatment

Simva — KM 32.4%

2079 events

EZ/Simva — KM 29.8%

1932 events

HR 0.924 CI (0.868, 0.983)

p=0.012


coronary revascularization (> 30 days after randomization), or stroke

7.6% Treatment effect

Primary Endpoint On Treatment

Simva — KM 32.4%

2079 events

EZ/Simva — KM 29.8%

1932 events

HR 0.924 CI (0.868, 0.983)

p=0.012


coronary revascularization (> 30 days after randomization), or stroke

19% greater treatment effect than ITT

NNT =38

7 year event rates

Simva* EZ/Simva* HR

Primary ITT 34.7 32.7 0.936

On Treatment 32.4 29.8 0.924

Secondary ITT 40.3 38.7 0.948

#1 OT 33.9 31.4 0.924


#2 OT 16.3 14.4 0.885


#3 OT 34.0 31.6 0.929

Ezetimibe/Simva

Better

Simva

Better

1 = All-cause death, major coronary event, or stroke post randomization

2 = CHD death, non-fatal MI, or urgent CABG or PCI (>30 days) after randomization

3 = CV death, non-fatal MI, documented UA requiring rehospitalization, all revascularization (>30 days)

after randomization, or non fatal stroke

*7-year event rates

Primary and 3 Prespecified Secondary Endpoints ITT & OT

0.8 1.0 1.1

HR Simva* EZ/Simva* p-value

All-cause death 0.99 15.3 15.4 0.782

CVD 1.00 6.8 6.9 0.997

CHD 0.96 5.8 5.7 0.499

MI 0.87 14.8 13.1 0.002

Stroke 0.86 4.8 4.2 0.052

Ischemic stroke 0.79 4.1 3.4 0.008

Cor revasc ≥ 30d 0.95 23.4 21.8 0.107

UA 1.06 1.9 2.1 0.618

CVD/MI/stroke 0.90 22.2 20.4 0.003

Ezetimibe/Simva

Better

Simva

Better

Individual Cardiovascular Endpoints and CVD/MI/Stroke

0.6 1.0 1.4*7-year

event rates (%)

Simva† EZ/Simva†

Male 34.9 33.3

Female 34.0 31.0

Age < 65 years 30.8 29.9

Age ≥ 65 years 39.9 36.4

No diabetes 30.8 30.2

Diabetes 45.5 40.0

Prior LLT 43.4 40.7

No prior LLT 30.0 28.6

LDL-C > 95 mg/dl 31.2 29.6

LDL-C ≤ 95 mg/dl 38.4 36.0

Major Pre-specified Subgroups

Ezetimibe/Simva

Better

Simva

Better

0.7 1.0 1.3†7-year

event rates

*

*p-interaction = 0.023, otherwise > 0.05

IMPROVE-IT vs. CTT: Ezetimibe vs. Statin Benefit

CTT Collaboration.

Lancet 2005; 366:1267-78;

Lancet 2010;376:1670-81.

IMPROVE-IT

Safety — ITT

No statistically significant differences in cancer or muscle- or gallbladder-related events

Simva

n=9077

%

EZ/Simva

n=9067

% p

ALT and/or AST≥3x ULN 2.3 2.5 0.43

Cholecystectomy 1.5 1.5 0.96

Gallbladder-related AEs 3.5 3.1 0.10

Rhabdomyolysis* 0.2 0.1 0.37

Myopathy* 0.1 0.2 0.32

Rhabdo, myopathy, myalgia with CK elevation* 0.6 0.6 0.64

Cancer* (7-yr KM %) 10.2 10.2 0.57

* Adjudicated by Clinical Events Committee % = n/N for the trial duration

Conclusions

IMPROVE-IT: First trial demonstrating incremental

clinical benefit when adding a non-statin agent (ezetimibe) to statin therapy:

YES: Non-statin lowering LDL-C with ezetimibereduces cardiovascular events

YES: Even Lower is Even Better(achieved mean LDL-C 53 vs. 70 mg/dL at 1 year)

YES: Confirms ezetimibe safety profile

Reaffirms the LDL hypothesis, that reducing LDL-C prevents cardiovascular events

Results could be considered for future guidelines

the resurrection of ezetimibe: a story of perseverance · 1 the resurrection of ezetimibe: a story...

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