Small molecule PSMA inhibitors for targeted molecular imaging of prostate cancer

Small molecule PSMA inhibitors for targeted molecular imaging of prostate cancer

John W. Babich, Ph.D.Whistler, 2008

The attraction of radioiodinesThe attraction of radioiodines

Decay modes and half lives availableGamma, beta, auger12h, 8d, 60d, I-123 has the highest practical specific activity and is ideal for SPECTI-131 is the most thoroughly studied and successful from a therapy perspectiveI-125 is excellent for ARG and in vitro and in vivo experimentation

Ease of substituting one iodine radionuclide for anotherImaging - to - therapy - to - imagingDetection - to - treatment -to - monitoring therapeutic response

Natural” fit from a medicinal chemistry approach Ease of incorporation into organic molecules – single covalent bond with carbonSimilar electro-negativity to carbonSimilar volume to methyl or ethyl group

Can be readily synthesized on a macroscaleEnables absolute structural elucidationEnables scale up for toxicological and pharmacological evaluation

Prostate Cancer and PSMAProstate Cancer and PSMA

Prostate cancer is the second leading cause of cancer-related deaths amongst men in the USA; ~200,000 men are diagnosed with prostate cancer each year, and ~30,000 will die from the diseaseChallenging to detect recurrent disease despite the availability of multiple imaging modalities including MRI, CT, bone scan, and several PET agentsPSMA is a membrane-bound protein expressed in normal prostate, and expression is increased in prostate cancer and numerous reports demonstrate a correlation of PSMA expression with PSA level, tumor stage, disease recurrence, and time to progressionRadiolabeled PSMA antibodies have met with limited success due primarily to the long plasma half-life and reduced tissue penetrability, and most likely the intracellular epitope in the case of ProstascintMIP is developing small molecules that bind to the catalytic domain of PSMA

PSMA: Structure and FunctionPSMA: Structure and Function

110 kDa, type II, highly glycosylatedtransmembrane proteinMember of a family of zinc-dependent exopeptidases with glutamate carboxypeptidase activity

NAALADase, FOLHI

Found in prostate, brain, kidney proximal tubules, intestinal brush border membranes, and tumor neovasculatureRole of PSMA in the prostate is unknown Filamin A Binding

Catalytic

Dimerization

Glycine-rich

Proline-rich

Transmembrane

N

C

UnknownFunction

Extracellular

Intracellular

Davis et al. (2005) Proc. Natl. Acad. Sci. USA 102, 5981-5986

Targeting the Active Site of PSMATargeting the Active Site of PSMA

Substrate binding domain contains

two basic subpockets.

The major basic patch binds

glutamate via electrostatic

interactions

Catalytic domain contains a

binuclear zinc binding site

coordinating a water molecule where

hydrolysis of peptide bond occurs

NAAG Binding to PSMA

Design of Glutamate Urea HeterodimersDesign of Glutamate Urea Heterodimers

S1 and S1’ permit structural modification to increase steric bulkS1’ is tolerant to relatively large hydrophobic groupsS2 and S2’ are intolerant to structural changesIt appears necessary to keep one glutamic acid unit intact

NH

COOH

COOH

NH

HOOC

COOH

O

H H

Kozikowski et al. J Med Chem. 2001 Feb 1;44(3):298-301.

S1 S1’

S2’S2 O

OHNH

O

NH

OHO

O

HO

HN RX

Glu-urea-Lys serves as an excellent building block for preparing potent PSMA inhibitors

NH2O

O

OO

NHO

O

OO

N

O

N

MeOTf, DCE

OTfNHO

O

OO

N

O

N

1)

2) hydrogenolysis

NH

NH

CO2t-Bu

O

O

O

OONH2

2 2B

4

H2N CO2t-Bu

NHCBZ

NO

O

OO

CO

DCM, CDI, TEA

triphosgene, TEA H2N CO2t-Bu

NHCBZ1)

2) hydrogenolysis

Route A

Route B

1

3

DCM = dichloromethaneCDI = carbonyldiimidazoleTEA = triethylamineMeOTf = methyl triflateCBZ = carboxybenzyloxy

Competitive Binding of Halogen-Containing Glutamate Urea Heterodimers to PSMA on LNCaP CellsCompetitive Binding of Halogen-Containing Glutamate Urea Heterodimers to PSMA on LNCaP Cells

0 0.001 0.01 0.1 1 100

30

60

90

120

Concentration (μM)

% o

f Con

trol

0 0.001 0.01 0.1 1 100

30

60

90

120

Concentration (μM)

% o

f Con

trol

NH

O

NH

O

OH

OHO

O

OH

HN

X

IC50 (nM)X2247

425 2

245 277 43

1200 2960

p-Io-I m-I p-Clo-Clm-Clp-Br p-F H

MIP-1072MIP-1035MIP-1089MIP-1107MIP-1137MIP-1131MIP-1094MIP-1090MIP-1106

-4 -3 -2 -1 0 10

30

60

90

120

MIP-1097MIP-1111

MIP-1129MIP-1110

MIP-1101MIP-1027

MIP-1095

Log Concentration (uM)

% o

f Con

trol

Competitive Binding of Halogen-Containing Glutamate Urea Heterodimers to PSMA on LNCaP CellsCompetitive Binding of Halogen-Containing Glutamate Urea Heterodimers to PSMA on LNCaP Cells

IC50 (nM)X102 412 10 20 3

p-Ip-Brp-ClHp-I p-I p-I

MIP-1095MIP-1129MIP-1110MIP-1111MIP-1097MIP-1101MIP-1027

NH

O

NH

O

OH

OHO

O

OH

HNR

X

(CO)NH(CO)NH(CO)NH(CO)NHSO2(CO)NHCH2CO

R

0 0.001 0.01 0.1 1 100

30

60

90

120

Concentration (μM)

% o

f Con

trol

0 0.001 0.01 0.1 1 100

30

60

90

120

% o

f Con

trol

Inhibition of the NAALADase Activity of PSMA by MIP-1072 and MIP-1095 Inhibition of the NAALADase Activity of PSMA by MIP-1072 and MIP-1095

NAALADase Inhibition (Ki)MIP-1072 6 nMMIP-1095 0.3 nM

NH

HN CO2H

CO2HO

CO2HO

NH

CO2H

H2N CO2H

CO2H

CO2HO

+

NAAGGlutamate

N-Acetylaspartate

Radiolabeling of MIP-1072Radiolabeling of MIP-1072

5 10 15 20 25 30 35

Minutes

2.5

5.0

7.5

10.0

mVolts

1.72

5 2.88

4

19.1

71

21.2

6721

.623

21.8

23

Channel: 1 = UV Results

0

100

200

300

400

500

600

mVolts

3.32

1

19.4

68Channel: 2 = Radio Results

WI:32WI:16

WI:8

WI:32

MIP-1072 Reference Standard

[123I]-MIP-1072

5 10 15 20 25 30Time (min)

10.07.55.02.5

600500400300200100

0

mV

olts

mV

olts

Radio

UV

RCY = 60-70%, Specific Activity >2000 mCi/μmole

O

OHNH

O

NH

OHO

O

HO

HN

123I

123I-MIP-1072O

ONH

O

NH

OO

O

O

HN

SnMe3 1) Na123I/Peracetic acid

2) TFA

5 10 15 20 25 30 35Minutes

0

50

100

150

200

0

200

400

600

mVo

lts

Radiolabeling of PSMA Inhibitor 123I-MIP-1095Radiolabeling of PSMA Inhibitor 123I-MIP-1095

RCY = 60%; RCP = 94%S.A. > 4000 mCi / µmol

UV-vis

Radio traceTime (RT) (40°C)

0 94.4 % 94.4 %

24 h 93.9 % 93.6 %

48 h 93.4 % 92.7 %

Radio-chemical Stability(pH 5 Gentisate/Ascorbate solution)

O

ONH

O

NH

OO

O

O

HN N

123I

O

OHNH

O

NH

OHO

O

HO

HN N

123I

O

ONH

O

NH

OO

O

O

HN N

SnMe3O OO

mVo

lts

123I-MIP-1095

General Synthetic Process for [123I]MIP-1095

O

ONH

O

NH

OO

O

O

HN NH

O SnMe3

Sn-MIP-1095 Precursor

1. [123I] NaI, oxidant

2. TFA/CH2Cl2

3. C18 Sep-Pak O

OHNH

O

NH

OHO

O

HO

HN NH

O123I

[123I]MIP-1095

This initial synthetic sequence resulted in a low RCY and reduced PSMA binding in vitro

Key Reaction Parameters Investigated

Iododestannylation reactionpHOrder of AdditionOxidantSolvents/solubilityReaction time

Deprotection of the intermediate t-butyl esterReaction timeSolvents

Purification of the desired final product, [123I]MIP-1095

Iododestannylation: Effect of pH

Peracetic acid oxidant and pH 2 afforded the highest RCY

O

ONH

O

NH

OO

O

O

HN NH

O SnMe3

Sn-MIP-1095 Precursor

[123I]NaIperacetic acid

sulfuric acidpH = 2 O

ONH

O

NH

OO

O

O

HN NH

O123I

[123I]MIP-1095-tri-t -butyl ester

Reaction pH RCY2 80%4 47%

5.5 30%

Iododestannylation: Order of Addition

Due to the lipophilicity of Sn-MIP-1095, organic solvents were introduced

Sn-MIP-1095 was added last due to its instability under acidic conditions

Performing the reaction directly in the 5 mL vial in which the [123I]NaI arrives allows for a faster, easier and safer manufacturing process

1. SWFI2. Acid

3. Oxidant4. AcCN

5. Sn-MIP-1095

[123I]NaI

Iododestannylation: Effect of Reaction Time & pH

O

ONH

O

NH

OO

O

O

HN NH

O SnMe3

Sn-MIP-1095 Precursor

[123I]NaIperacetic acid

sulfuric acidpH = 2 O

ONH

O

NH

OO

O

O

HN NH

O123I

[123I]MIP-1095-tri-t-butyl ester

Prolonged reaction time (> 10 min) led to deprotection of one or more of the t-butyl ester protecting groups of [123I]MIP-1095-tri-t-butyl ester leading to low RCY

Iododestannylation: Effect of Reaction Time & pH

Minutes

13.7

Exposure to radioiodination conditions for 10 minutes

5 10 15 20 25

mV

olts

0

50

13.7

0

20

80

0

100

40

30

40

0

0

20

Reference standard

Exposure to radioiodination conditions for 15 minutes

O

ONH

O

NH

OO

O

O

HN NH

O I

MIP-1095 tri-t-butyl ester

UV-Vis Chromatogram

Iododestannylation: Effect of Solvent

Sn-MIP-1095 precursor was soluble in organic solvents (i.e. AcCN, MeOH)

Deprotection of the t-butyl groups in the presence of trace amounts of methanol resulted in the formation of methyl esters

Use of t-butanol resulted in t-butyl formation during re-esterification, however, RCY less than 40% were obtained

O

ONH

O

NH

OO

O

O

HN NH

O SnMe3

Sn-MIP-1095 Precursor

[123I]NaIperacetic acid

sulfuric acidpH = 2 O

ONH

O

NH

OO

O

O

HN NH

O123I

[123I]MIP-1095-tri-t -butyl ester

t-Butyl Ester Deprotection: Effect of Solvent

The presence of trace amounts of methanol resulted in the formation of a mixture of methyl ester side products during t-butyl deprotection step

OON

H

ONH

OO

OO

HN NH

O123I

TFA/CH2Cl2

trace methanol

OOHN

H

ONH

OMeO

OHO

HN NH

O123I

OOHN

H

ONH

OMeO

OMeO

HN NH

O123I

OOMeN

H

ONH

OMeO

OMeO

HN NH

O123I

+

t-Butyl Ester Deprotection: Effect of Reaction Time

mV

olts

5 10 15 20 25

Minutes

0

400

13.3

0

500

1500

10.9

0

10.913.3

30

1000

800

5 10 15 20 25

0

400

0

500

1500

030

800MIP-1095 tri-t-butyl ester reference standard

t-butyl deprotection after 35 minutes

Co-injection MIP-1095 and MIP-1095 tri-t-butyl ester reference standards

O

ORNH

O

NH

ORO

O

RO

HN NH

O I

R = H, C(CH3)3

UV-Vis Chromatograms

Purification Optimization for [123I]MIP-1095

A major side product, the des-iodo analog, MIP-1111, was active in vitro

The 1st C18 Sep-Pak removes the majority of Sn side products and unreacted [123I]NaI

The 2nd C18 Sep-Pak separates the desired product, [123I]MIP-1095, from MIP-1111

O

ONH

O

NH

OO

O

O

HN NH

OSnMe3

O

OHNH

O

NH

OHO

O

HO

HN NH

O123I

[123I]MIP-1095

Sn-MIP-1095 Precursor

1. [123I] NaI

O

OHNH

O

NH

OHO

O

HO

HN NH

O H

MIP-1111

+3. TFA/CH2Cl2

O

OHNH

O

NH

OHO

O

HO

HN NH

O123I

[123I]MIP-1095

C18 Sep-Pak2. C18 Sep-Pak

ActiveSide Product

HPLC Analysis: Single Sep-Pak Purification

O

OHNH

O

NH

OHO

O

HO

HN NH

OH

RadioChromatogram

UV-VisChromatogram

5 10 15 20 25 30 35

0

25.6 min

0

20

11.7 min

10

Volts

0.5

1.0

5 10 15 20 25 30 35

Minutes

mVo

lts

[123I]MIP-1095

MIP-1111

O

OHNH

O

NH

OHO

O

HO

HN NH

O123I

HPLC Analysis: Double Sep-Pak Purification

0

0.5

1.0

0

10

20

25.6 min

11.7 min

[123I]MIP-1095

RadioChromatogram

UV-VisChromatogram

O

OHNH

O

NH

OHO

O

HO

HN NH

O123I

O

OHNH

O

NH

OHO

O

HO

HN NH

OH

MIP-1111

5 10 15 20 25 30 3510 15 20 25 30 35

Minutes

Volts

mVo

lts

Effect of Specific Activity on Binding to LNCaP Cells In Vitro

Single Sep-Pak Apparent SA at TOI = 208 mCi/µmol (MIP-1095 + MIP-1111) Double Sep-Pak SA at TOI > 4800 mCi/µmol (MIP-1095)(TOI = Time of Injection)

0

30

60

90

120

No Competitor 10 µM Unlabeled MIP-1095

10 µM PSMA Inhibitor(PMPA)

fmol

bou

nd

Double Sep-PakSingle Sep-Pak

Current Manufacturing Process for [123I]MIP-1095

t-Butyl-123I-MIP-1095 + t-Butyl-MIP-1111

Na123I

H2SO4 C18 Sep-Pak

TFA CH2Cl2

123I-MIP-1095 + MIP-1111 (active)

C18 Sep-Pak

t-Butyl-Sn-MIP-1095

123I-MIP-1095

Peracetic Acid

Direct Binding of [123I]-MIP-1072 and [123I]-MIP-1095 to Prostate Cancer CellsDirect Binding of [123I]-MIP-1072 and [123I]-MIP-1095 to Prostate Cancer Cells

P

O

OHHO COOH

COOH

PMPA

0

50

100

150

200

NoCompetitor

10 uMUnlabeledMIP-1072

10 uMPMPA

0

30

60

90

120

LNCaP (PSMA +)PC3 (PSMA -)

fmol

Bou

nd

123 I-MIP-1072 123 I-MIP-1095

LNCaP (PSMA +)PC3 (PSMA -)

fmol

Bou

ndNo

Competitor 10 uM

UnlabeledMIP-1095

10 uMPMPA

0

50

100

150

200

NoCompetitor

10 uMUnlabeledMIP-1072

10 uMPMPA

0

30

60

90

120

LNCaP (PSMA +)PC3 (PSMA -)

I-MIP-1072 I-MIP-1095

LNCaP (PSMA +)PC3 (PSMA -)

NoCompetitor

10 uMUnlabeledMIP-1095

10 uMPMPA

Saturation Binding to PSMA on LNCaP Cells of [123I]-MIP-1072 and [123I]-MIP-1095 Saturation Binding to PSMA on LNCaP Cells of [123I]-MIP-1072 and [123I]-MIP-1095

MIP-1072 3.8 ± 1.4 1490 ± 62MIP-1095 1.08 ± 0.03 1680 ± 107

Kd (nM) Bmax (fmol/106 cells)

MIP-1095MIP-1072

0.001 0.01 0.1 1 10 100 10000

500

1000

1500

Concentration (nM)

fmol

Bou

nd/1

06ce

lls

MIP-1095MIP-1072MIP-1095MIP-1072MIP-1095MIP-1072

0.001 0.01 0.1 1 10 100 10000

500

1000

1500

Concentration (nM)

fmol

Bou

nd/1

06ce

lls

0.001 0.01 0.1 1 10 100 10000

500

1000

1500

Concentration (nM)

fmol

Bou

nd/1

06ce

lls

Cell Internalization of [123I]-MIP-1072 and [123I]-MIP-1095Cell Internalization of [123I]-MIP-1072 and [123I]-MIP-1095

MIP-1095

0 20 40 60 80 100 1200

500

1000

1500

2000

2500 Total 4C

Total 37CInternalized 4 C

Internalized 37C

Time (min)

fmol

Bou

nd

MIP-1072

0 20 40 60 80 100 1200

400

800

1200

1600

2000Total 4C

Total 37CInternalized 4 C

Internalized 37C

Time (min)

fmol

Bou

nd

Tissue Distribution of [123I]-MIP-1072 in LNCaP Bearing MiceTissue Distribution of [123I]-MIP-1072 in LNCaP Bearing Mice

15 min 1 hr 2 hr 4 hr 8 hr 24 hrTumor:Blood 5 37 65 220 176 411Tumor:Muscle 16 50 70 432 446 64

Time post injection

Blood

Heart

Lungs

Liver

Spleen

Kidneys

Intestin

eSk.M

uscle

Tumor

0

10

20

30

40

15 min1 hr2 hr4 hr8 hr24 hr

40

140

240

%In

ject

ed D

ose/

gram

18 %ID/g

Tissue Distribution of [123I]-MIP-1095 in LNCaP Bearing MiceTissue Distribution of [123I]-MIP-1095 in LNCaP Bearing Mice

15 min 1 hr 2 hr 4 hr 8 hr 24 hrTumor:BloodTumor:Muscle

Time post injection

2 11 24 41 57 1749 49 81 133 121 304

Blood

Heart

Lungs

Liver

Spleen

Kidneys

Intestin

eSk.M

uscle

Tumor

0

10

20

30

40

15 min1 hr2 hr4 hr8 hr24 hr

40

140

240

%In

ject

ed D

ose/

gram

18 %ID/g

Tumor Uptake of 111In-J591, 111In-ProstaScint and 111In-Mouse IgG Bio-Distribution in LNCaP Xenograft MiceTumor Uptake of 111In-J591, 111In-ProstaScint and 111In-Mouse IgG Bio-Distribution in LNCaP Xenograft Mice

Blood Clearance

0

10

20

30

40

0 20 40 60 80

Time (hr)

%ID

/g

Mouse IgGProstaScint111In-J591

Tumor Clearance

0

10

20

30

40

50

60

0 20 40 60 80

Time (hr)%

ID/g

Mouse IgGProstaScint111In-J591

Comparison of Clearance of MIP-1072 and MIP-1095 From Selected TissuesComparison of Clearance of MIP-1072 and MIP-1095 From Selected Tissues

Blood Clearance

0

1

2

3

4

5

0 5 10 15 20 25

Time (hr)

%ID

/g

MIP-1095MIP-1072

Kidney Clearance

0

50

100

150

200

250

0 5 10 15 20 25

Time (hr)

%ID

/g

MIP-1095MIP-1072

Skeletal Muscle Clearance

0

0.3

0.6

0.9

1.2

0 5 10 15 20 25

Time (hr)

%ID

/g

MIP-1095MIP-1072

Tumor Clearance

0

10

20

30

40

50

0 5 10 15 20 25

Time (hr)

%ID

/g

MIP-1095MIP-1072

Tissue Distribution of [111In]-Prostascint in LNCaP Bearing MiceTissue Distribution of [111In]-Prostascint in LNCaP Bearing Mice

Blood

Heart

Lung

s

Liver

Spleen

Kidney

sInt

estin

e Sk.M

uscle

Tumor

0

15

30

45

60 1 hr4 hr24 hr48 hr72 hr

%In

ject

ed D

ose/

gram

0.25 1 2 4 8 24 48 72 (Hours)

Tumor/blood MIP-1072 5 37 65 220 176 411 - -MIP-1095 2 11 24 41 57 174 - -Prostascint - 0.1 - 0.3 - 1 2 3

Tumor/muscle MIP-1072 16 50 70 432 446 64 - -MIP-1095 9 49 81 133 121 304 - -Prostascint - 3 - 12 - 20 31 48

Specific Binding to PSMA is Demonstrated by PMPA Blocking in VivoSpecific Binding to PSMA is Demonstrated by PMPA Blocking in Vivo

Unblocked50 mg/kg PMPA Blocked

Unblocked50 mg/kg PMPA Blocked

LNCaP (PSMA +) Tumor PC3 (PSMA -) Tumor

[123I]-MIP-1072

BloodLungs

Liver

Kidneys

Intestin

eSk.M

uscle

Tumor

0

5

10

15

20

25100

150

200

%In

ject

ed D

ose/

gram

[123I]-MIP-1095

BloodLungs

Liver

Kidneys

Intestin

eSk.M

uscle

Tumor

0

5

10

15

20

2525

100

175

%In

ject

ed D

ose/

gram

Selective Targeting of PSMA In Vivo with [123I]-MIP-1072 and [123I]-MIP-1095 (SPECT/CT 4 hour)Selective Targeting of PSMA In Vivo with [123I]-MIP-1072 and [123I]-MIP-1095 (SPECT/CT 4 hour)

LNCaP

LNCaP

MIP-1072 MIP-1095

Selective Targeting of PSMA In Vivo with [123I]-MIP-1072 and [123I]-MIP-1095 (SPECT/CT at 2 Hours)Selective Targeting of PSMA In Vivo with [123I]-MIP-1072 and [123I]-MIP-1095 (SPECT/CT at 2 Hours)

PC-3 flu(PSMA-)

PC-3 PIP(PSMA+)

PC-3 PIP(PSMA+)

PC-3 flu(PSMA-)

Selective Targeting of PSMA In Vivo with [123I]-MIP-1095 (SPECT/CT)Selective Targeting of PSMA In Vivo with [123I]-MIP-1095 (SPECT/CT)

2 h p.i. 4 h p.i. 24 h p.i.

PC-3 PIP(PSMA+)

PC-3 flu(PSMA-)

Selective Targeting of PSMA with [123I]-MIP-1095 in a Baboon (SPECT/CT 4-6 hr)Selective Targeting of PSMA with [123I]-MIP-1095 in a Baboon (SPECT/CT 4-6 hr)

LNCap

PC3Renal C

ortex

Prostate

Parotid Gland

Renal Corte

x

Prostate

Parotid Gland

Baboon 16100 Baboon 16951

PSMA PSMA

Ex Vivo Binding of [123I]-MIP-1072 and [123I]-MIP-1095 to Human Prostate TissueEx Vivo Binding of [123I]-MIP-1072 and [123I]-MIP-1095 to Human Prostate Tissue

[123I]-MIP-1095[123I]-MIP-1072 H&E Staining

Red = cancerBlue = normalGreen = non-cancer

abnormal

Ex Vivo Binding of [123I]-MIP-1072 to Human Prostate TissueEx Vivo Binding of [123I]-MIP-1072 to Human Prostate Tissue

Prostate Cancer

(#111710B3)

Prostate Cancer

(#117196B1)

Normal Prostate

(#8979C1)

Benign Prostatic

Hyperplasia(#11145A1)

Renal Cortex

(#12001A7)

123I-MIP-1072 + 10 μM cold MIP-1072

[123I]-MIP-1072

123I-MIP-1095 Dipping Study123I-MIP-1095 Dipping Study

Prostate Cancer

(#111710B3)

Prostate Cancer

(#117196B1)

Normal Prostate(#15187F1)

Benign Prostatic Hyperplasia

(#22040B1)

Renal Cortex(#8346A1)

123I-MIP-1095

123I-MIP-1095 + 10 μM cold MIP-1095

Safety Findings for MIP-1072 and MIP-1095Safety Findings for MIP-1072 and MIP-1095

Target dose administered: 10 mCi, < 3 μg, or < 3 nM

Expanded acute rat studyNo adverse effects observed at doses > 300X the human equivalent dose

Cardiovascular effects in conscious dogs (arterial pressure, heart rate and ECG)

No adverse effects observed at doses > 300 times human equivalent dose

General pharmacology screen (NovaScreen™)No effects observed at concentrations up to 1 µM

No stimulatory or inhibitory effects on LNCaP cell growthRadiation dose estimates and starting dose in man were extrapolated from rat tissue distribution study

[123I]-MIP-1072 and [123I]-MIP-1072 Initial Clinical Plan[123I]-MIP-1072 and [123I]-MIP-1072 Initial Clinical Plan

IND recently filed and approvedSingle-blinded, randomized, crossover study in 12 patients with histological confirmed prostate cancer and evidence of recurrent disease10 mCi dose of each, 14 days apartPrimary objective is to evaluate dosimetry, safety, pharmacokinetics, and tissue distribution3 day assessment period

Blood and urine collectionAnterior and posterior planar imagingSPECT/CT

2 week follow-up post 2nd injectionInterim data review once the first 6 patients have been evaluated

[123I]-MIP-1072

[123I]-MIP-1095

Previously Known Lumbar spinal metastatic lesion

Unknown Suspected metastatic lymph node

CT scanalone

Trofex SPECT image (color)

fused withCT scan

Initial Clinical Data with [123I]-MIP-1095Initial Clinical Data with [123I]-MIP-1095

Initial Clinical Data with [123I]-MIP-1095Initial Clinical Data with [123I]-MIP-1095

ConclusionsConclusions

A series of novel halogen-containing glutamate urea heterodimersbased on glutamate-urea-lysine were designed and synthesized

Two lead iodine-containing compounds from this series were identified (MIP-1072 and MIP-1095) that bind with high affinity to PSMA

Both compounds selectively accumulate in PSMA positive human prostate cancer xenografts but exhibit different pharmacokinetics

MIP-1072 and MIP-1095 are currently being evaluated in an exploratory IND and may permit the more accurate diagnosis and staging of prostate cancer, and enable the monitoring of therapy

Preliminary results in humans confirm that MIP-1095 accumulates in metastatic prostate cancer

AcknowledgementsAcknowledgements

MIPKevin Maresca, Ph.DFrank Femia, Ph.DCraig Zimmerman, Ph.DJohn Joyal, Ph.DShawn Hillier, Ph.DJohn Marquis, Ph.DJames Kronauge, Ph.DBrian Abeysekera, Ph.DEd Luss-Lusis, Ph.DNorman LaFrance, M.D.William Eckelman, Ph.DJohn Babich, Ph.D.

Duke UMC P1 human studiesEd Coleman, M.D.Dan George, M.D.

JHU animal imaging studiesMartin Pomper, M.D., Ph.DCatherine Foss, Ph.D