Transcript Test Title

Next Generation Inhibitors of HIV-1
Integrase Strand Transfer:
Structural Diversity and
Resistance Profiles
John Wai
Merck Research Laboratories
West Point, PA
14th CROI
February 27, 2007
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
HIV Life Cycle
2
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
MK-0518: Raltegravir
N N
H
N
O
F
O
H
N
N
N
O
O
OH
• Potent integrase strand transfer inhibitor (IC50 ~ 10 nM)
• Antiviral IC95 ~ 33  23 nM (50% NHS)
• Retains potency across diverse clinical isolates, HIV-2
• Potent antiviral effect in treatment naïve patients
(Markowitz et al IAC 2006)
• Robust activity in HIV-1 patients with triple class resistance
– Phase II 24 week data (Grinsztejn et al CROI 2006)
– Phase III data (Cooper et al & Steigbigel et al CROI 2007)
• Lipid neutral in naïve patients (Mascolini et al ICAAC 2006)
• Few drug interactions; Metabolized via glucuronidation
3
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Objectives for 2nd generation InSTI
MAINTAIN favorable properties of Raltegravir with
respect to
• efficacy,
• tolerability, lipid profile
• few drug interactions
and ACHIEVE
• Once daily dosing (stand alone)
• Activity against InSTI resistant isolates
Question: Clinical resistance profile of InSTIs???
4
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In Vitro Selection for Mutants
Catalytic Residues
E152
D64
D116
Mg
5
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In Vitro Selection for Mutants
Catalytic Residues
Diketoacid
Naphthyridine L-810
S153
M154
I151
E152
N155
D64
D116
T66
F121
Mg
V72
6
T125
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
In Vitro Selection for Mutants
Catalytic Residues
Diketoacid
Q148
Naphthyridine L-810
S153
Pyrimidine MK-518
M154
G140
I151
E138
E152
• Bind to catalytic site
N155
D64
D116
• Different inhibitors
selected for different
sets of mutants
T66
F121
Mg
V72
7
• Multiple possible
binding orientations
T125
• Mutation points are
spread around the
catalytic site
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Enabling Tool: Mutant Panel
Catalytic Residues
Diketoacid
Q148
Naphthyridine L-810
S153
Pyrimidine MK-518
G140
E138
N155
• Mutant viruses
constructed using site
directed mutagenesis
T66
F121
• Activity assessed with
single cycle infectivity
assay
Mg
V72
8
T125
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Diversification of DKA Isosteres
Diketoacid
Pharmacophore
O
N
N
N
OH
N
O
O
O
OH
N
N N
X
N
N
O
O
OH
OH
X = CH, NH
O
N X
N
N
N
N
O
OH
N
O
N
OH
N
OH
OEt
O
O
O
N
O
OH
H
9
O
OH
X = CH, NH
OH
O
C2 symmetry
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Optimization Against InSTI Mutants
Ratio of IC50’s in
Infectivity assay
T66I/
S153Y
F
O
F
MeHN
O
F
Cl
N
N
OH
10
76x
31x
90x
20x
9
1x
2x
2x
16x
1x
1x
1x
N
MK-2048
O
N
N
N
N
O
22x
O
N
O S
O N
N
156
O
OH
N
N
Cl
Spread
ClC95 nM
N
N
E138A/
G140A/
N155S Q148K Q148K F121Y
OH
O
N
O
0.8
OH
N
O
1x
1x
1x
Benchmark
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Comparison with Clinical Candidates
Screening Mutant Panel
IC50 ratio of mutants vs. WT HIV-1
in infectivity assay
169X
11
116X
100
395X
80
388X
60
40
20
0
GS-9137
MK-518
MK-2048
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
IC50 ratio of mutants vs. WT HIV-1
in infectivity assay
Comparison with Clinical Candidates
MK-518 Clinical Isolates
399 / 2194X
300
200
100
0
GS-9137
MK-518
MK-2048
12
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Numbers of weeks of incubation for the
first emergence of mutation in all isolates
Time to Selection of Resistance in
Cell Culture
13
40
30
>37 wk
>37
wk
• Selection of Resistance in cell culture at IC95
• Time taken for the first emergence of mutant
in vitro correlates with mutation profiles of
inhibitors
20
10
Compound A
MK-518
Compound B
0
MK-2048
Weeks
Primary
Mutation
# of
Clones
7
11
N155H
Q148K
5/5
6/6
21
S153Y
7/7
>37
T112I
5/12
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
Summary: Second Generation InSTIs
IC50 ratio of mutants vs. WT HIV-1
in infectivity assay
169X
100
80
116X
395X
388X
60
40
20
0
GS-9137
MK-518
MK-2048
• Resistance profiling leads to the identification of inhibitors with
activity against broad spectrum of integrase resistance isolates.
• Provides Proof of Concept for developing second generation InSTIs.
14
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved
2nd Generation HIV-1 InSTIs Discovery Team
Medicinal Chemistry
Thor Fisher
Mark Embrey
Bo-young Kim
Melissa Egbertson
Wei Han
Debbie Perlow
Rowena Ruzek
Peter Williams
Marie Langford
Janetta Pellicore
Donnette Staas
Vanessa Sherman
Kelly Savage
Cathy Wiscount
Lee Tran
Melody McWherter
Linghang Zhuang
Kyle Robinson
Matt Morrissette
Lou Anne Neilson
Richard Isaacs
Linda Payne
Rick Pracitto
Vanessa Obligado
Wayne Thompson
Peter Munson
Brian Phillips
John Wai
Terry Lyle
Joe Vacca
15
Biological Chemistry
Daria Hazuda
Mike Miller
Jay Grobler
Pete Felock
Kara Stillmock
Amy Simcoe
Marc Witmer
Alysha Day
Robert Danovich
Yuxiong Ke
Viral Vaccine Research
Jessica Flynn
Linda Ecto
Sinouen Touch
Lori Gabryelski
Bill Schleif
Drug Metabolism
Chuck Thompson
Prasad Kari
Joan Ellis
Kim Michel
Anne Taylor
Reza Anari
Chris Kochansky
Pharm R&D
Dave Dubost
Wei Xu
Scale-up Lab
John Swestock
Rick Woodward
Randy Newton
Kim Strauss
Jim Guare
NMR & MS Groups
Steve Pitzenberger
Sandor Varga
Mike Bogusky
Janine Brouillette
Chuck Ross
Joan Murphy
Molecular Modeling
Kate Holloway
Chris Culberson
Analytical Group
Kristi Hoffman
Ken Anderson
Matt Zrada
Amanda Cortes
Deanne Rudd
Chromatography Group
Carl Homnick
Todd Anderson
Christy Olson
Copyright © 2007 Merck & Co., Inc., Whitehouse Station, New Jersey, USA All rights Reserved