CCR5 Monoclonal Antibody CCR5 Monoclonal Antibody PRO 140 Inhibited HIV-1 PRO 140 Inhibited HIV-1 Resistant to Maraviroc, a Small Resistant to Maraviroc, a Small Molecule CCR5 AntagonistMolecule CCR5 Antagonist

CCR5 Monoclonal Antibody CCR5 Monoclonal Antibody PRO 140 Inhibited HIV-1 PRO 140 Inhibited HIV-1 Resistant to Maraviroc, a Small Resistant to Maraviroc, a Small Molecule CCR5 AntagonistMolecule CCR5 Antagonist

Andre J Marozsan

Progenics Pharmaceuticals, Inc.

IAS 2008

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PRO 140 BackgroundPRO 140 Background

Humanized CCR5 monoclonal antibody

Broadly and potently inhibits CCR5-mediated HIV-1 entry in vitro

Distinct class of CCR5 inhibitor

– Binds extracellular domains vs. transmembrane pocket

• Inhibits HIV without blocking the natural activity of CCR5 in vitro

– Inhibits HIV via competitive vs. allosteric mechanism– Synergistic with small-molecule CCR5 antagonists– Potential for improved tolerability without drug-drug or

drug-food interactions– Potential for infrequent dosing

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0 1 0 2 0 3 0 4 0 5 0 6 0

Stu d y Da y

-2 .0

-1 .5

-1 .0

-0 .5

0 .0

0 .5

Me

an

Lo

g1

0 C

ha

ng

e i

n H

IV-1

RN

A

P la c e b o 0 .5 m g /k g 2 m g /k g 5 m g /k g

+++

+++

+++

+++

+++

+++

+++++

+ p ≤ 0.01++ p ≤ 0.001

+++ p ≤ 0.0001

PRO 140 Background (2)PRO 140 Background (2)

Potent, rapid, prolonged, dose-dependent antiviral activity in HIV-infected individuals

– 1.8 log10 mean reduction in HIV RNA following single 5 mg/kg IV dose

– >1.0 log10 mean reduction in HIV RNA for 2-3 weeks post-treatment

– Individual reductions up to 2.5 log10

Generally well tolerated

Designated FDA Fast Track drug candidate

IAS 2008

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History of Case C Primary IsolatesHistory of Case C Primary Isolates

DateCD4

cells/mm3

MT2phenotype

Replication in HOS.CD4 cells[p24] (pg/ml)

CCR2 CCR3 CCR5 CXCR4

5/84 1,233 NSI <30 <30 1,024 <30

1/85 1,038 NSI <30 <30 72,400 <30

2/86 1,049 SI <30 <30 84,800 1,666

7/86 485 SI <30 <30 60,200 65,600

12/86 346 SI 16,240 12,700 31,000 43,100

5/87 141 SI 1,200 1,586 28,800 54,800

6/88 186 SI <30 <30 30,300 19,460

11/89 38 SI 6,600 11,240 31,200 24,000Conner et al. 1997. J. Exp. Med. 185:621-628.•Subtype B isolate

•Patient switched to X4 phenotype•Used as parental virus for AD101, vicriviroc and maraviroc escape studies

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Generation of Resistance: MethodsGeneration of Resistance: Methods

Culture for generation of resistance: Infect pooled donor PBMC with CC1.85 virus and culture in the presence

and absence of maraviroc. Begin escape cultures with drug concentration at the IC90. Passage cultures each week and monitor p24 production. Double inhibitor concentrations if p24 levels are stable in the culture. Cultures are considered resistant when viral replication is stable at the

highest concentration of drug for two weeks. Collect viral supernatants after 48 hours of drug-free growth.Generation of HIV-1 envelope clones and testing: Viral supernatants were analyzed at Monogram Biosciences (South San

Francisco, CA) using TrofileTM and PhenosenseTM Entry assays, as well as sequencing of the viral swarm.

Clonal analysis is in progress.

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Generation of Maraviroc- Resistant VirusGeneration of Maraviroc- Resistant Virus

0

0.5

1

1.5

2

2.5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Week

p2

4 G

row

th (

ng

/ml)

1

10

100

1000

10000

[ma

rav

iro

c]

nM

CC1.85 MVC EscapeCC1.85 PC[maraviroc] nM

Escape cultureIsolated atWeek 31

Passage controls isolated at Weeks 27 and 36

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Tropism AnalysisTropism Analysis

Passage Control Virus was R5-tropic at week 27

TrofileTM Analysis of Viral Swarm

100

1000

10000

100000

1000000

R5-RLU X4-RLU

U87.CD4.Coreceptor

RL

U

CC1.85 Parental

CC1.85 Passage Control wk 36

CC1.85 MVC Escape

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Maraviroc ResistanceMaraviroc Resistance

CC1.85 CC1.85 Passage Controlwk 27

CC1.85 MVC Escape

IC50 10 nM 11 nM not applicable

MPI 99% 100% 48%

PhenosenseTM Entry Assay Results

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PRO 140 SensitivityPRO 140 Sensitivity

CC1.85 CC1.85 MVC Escape

IC50 0.44 ug/mL 0.32 ug/mL 0.49 ug/mL

2.9 nM 2.1 nM 3.3 nM

MPI 98% 93% 98%

PhenosenseTM Entry Assay Results

CC1.85 Passage Controlwk 27

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Case C 1.85 SequencesCase C 1.85 Sequences

300 ^^^ CTRPNNNTRKSIHIGPGRAFYATGDIIGDIRQAHC......Y......M.....W.................................T..S...V...........................T..S...V.........

CC1.85 Parental IsolateCC1.85 Passage ControlCC1.85 MVC Escape

R5

R5DM

V1/V2 - a two amino acid deletion at positions 188-189 was observed in the maraviroc escape virus and in the passage control virus. This deletion was observed in prior Case C escape cultures and was associated with increased CD4 dependence (Pugach et al. Virology. 321:8-22. 2004).

V3 Region

R5CC1.85 MVC Escape(Pfizer*)

*Westby et al. 2007. J. Virol. 81:2359-2371

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Summary of Viral CharacteristicsSummary of Viral Characteristics

Virus Tropism Inhibitor IC50 MPI

CC 1.85 ParentalR5 PRO 140

0.44 ug/mL2.9 nM

98

Maraviroc 10 nM 99

CC 1.85 MVC EscapeWk 31

R5 PRO 1400.49 ug/mL

3.3 nM98

Maraviroc >6 uM 48

CC 1.85 Passage ControlWk 27

R5 PRO 1400.32 ug/mL

2.1 nM93

Maraviroc 11 nM 100

CC 1.85 Passage ControlWk 36

DM PRO 140 NA NA

Maraviroc NA NA

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SummarySummary

A virus resistant to maraviroc was generated in PBMC culture over 31 weeks of passage.

The maraviroc escape virus remained R5; however, the passage control virus became R5X4.

The maraviroc escape virus displayed similar phenotype and sequence to one generated by Pfizer.

For Case C 1/85, maraviroc resistance did not confer cross-resistance to PRO 140.

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AcknowledgmentsAcknowledgments

Progenics Pharmaceuticals, Inc.

• Tom Ketas• William Olson, Ph.D.• Paul Maddon, M.D., Ph.D.

Monogram Biosciences, Inc.

• Wei Huang, Ph.D.• Jonathan Toma, Ph.D.• Jeannette Whitcomb, Ph.D.• Chris Petropoulos, Ph.D.

This study was supported byPublic Health Service awardAI066329 from the National

Institute of Allergy and Infectious Diseases