STRUCTURE and ACTIVITYof DRUGS

- practical aspects I.

György Domány

Scientific adviserGedeon Richter Plc.

1

What is the goal of thepharmaceutical industry?

What is the goal of (industrial) drug research?

2

3

„We try to remember that medicines are for the patient. Wetry never to forget that medicine is for the people. It is notfor profit. The profits follow and if we’ve remembered that, they have never failed to appear. The better we haveremembered it, the larger they have been.”

George W. Merck, former president of Merck & Co.

STRUCTURE ACTIVITY

4

N

N O

N

N

FO

Me

NMe Me

COOMeMeOOC

NO2

H

COOH

O

MeO

aspirin

nifedipine

risperidone

analgetic, antipyretic, antiinflammatory

antihypertensive, antianginal

antipsychotic

5

„Corpora non agunt nisi fixata(drugs will not act unless they are bound) ”

Paul Ehrlich

STRUCTURE ACTIVITY

6

NMe Me

COOMeMeOOC

NO2

H

COOH

O

MeO

aspirin

nifedipine

risperidone

analgetic, antipyretic, antiinflammatory

cyclooxygenase (COX) inhibitor

antihypertensive, antianginal

L-type Ca-channel blocker

antipsychotic

dopamine D2 receptor antagonistN

N O

N

N

FO

Me

7

Cyclooxygenase (COX)

8

Calcium channel

NMe Me

COOMeMeOOC

NO2

H

9

Dopamine D2 receptor

N

N O

N

N

FO

Me

10

STRUCTURE,MoA/BIOLOGICAL

TARGET,ACTIVITY

11

The discovery of aspirin

- 400 B.C. Hippocrates recommended a brew made from willow leavesto treat labour pains.

- 1763 Reverend Edward Stone described the benefits he observedafter giving ground up willow bark to 50 parishioners suffering fromrheumatic fever.

- 1897 Felix Hoffmann/Arthur Eichengrün of Bayer developed theprocess of synthesizing the acetyl salicylic acid named later as aspirin.

COOH

OH

COOH

O

MeO

- 1970s the British scientist Professor John Vane discovered that aspirinblocks cyclooxygenase needed for the production of prostaglandins.

12

How to find a new andbetter antiinflammatory

drug?

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Symptoms of inflammation

„calor” heat„dolor” pain„rubor” redness„tumor” swelling

„functio laesa” loss of function

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Synthesis of new compounds

↓

Testing on the hot-plate

Phenotypic drug discovery(PDD)

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A phenotype is the composite of an organism's observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior (such as a bird's nest).

A phenotype results from the expression of an organism's genetic code, its genotype, as well asthe influence of environmental factors and theinteractions between the two.

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Synthesis of new compounds

↓

Screening COX inhibition

↓

Testing on the hot-plate

Target based drug discovery(TDD)

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PDD & TDD

SynthesisAnalysis

Synthesis Analysis

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

Analysis-1

Analysis-5

Analysis-2 Analysis-3

Analysis-7 Analysis-6

Analysis-8

Analysis-4

Synthesis

„Property”

„In vivo

activity”(pharmacodynamics)

„Virtual – insilico - activity”

„In vitro

activity”

„In vivo

toxicology”„In vivo ADME”(pharmakokinetics)

„Safetypharmacology”

„In vitro

ADME”

SCREENING CASCADE

Cariprazine

„antipsychotic, dopamine D3/D2 receptor functional antagonist” 37

38

Psychosis is an abnormal condition of the mindthat results in difficulties telling what is realand what is not. Symptoms may include falsebeliefs and seeing or hearing things that othersdo not see or hear. Other symptoms may includeincoherent speech and behavior that isinappropriate for the situation. There may alsobe sleep problems, social withdrawal, lack ofmotivation, and difficulties carrying out dailyactivities.

https://en.wikipedia.org/wiki/Psychosis

Dopamine theory of psychosis

Contemporary pathophysiological models assume that psychotic symptoms are triggered by a dysregulationof dopaminergic activity in the brain, a theory that istightly linked to the serendipitous discovery of the firsteffective antipsychotic agents in the early 1950s.

Tost, H. et al. Neurosci. Biobehav. Rev. (2010) 34 (5), 689-700.

39

dopamine

NH2

HO

OH

40

41

42

43

44

45

46

47

48

49

The first project: 1990s

Goal: at first „Cavinton follow-up”, then antipsychotic

50

Q2

O N

XQ1

( )n

Q1: substituted phenyl or benzylX: N or CHn: 2-5Q2: heterocycle or heterobicycle

CUF/ADD/MADD/APP

51

Combinatorial approach

52

Q

O N

N

OCH3( )n

n: 2-4

N NN

NN

S

NN

S

NN

N

The first compound library

53

OMe

N

NO

N

N

S

RGH-1756

D3-IC50: 2.6 nM; D2-IC50: 20 nMBA: 21%; „climbing”- ED50: 16 mg/kg

54

OMe

N

NO

N

N

S

RGH-1756

D3-IC50: 2.6 nM; D2-IC50: 20 nMBA: 21%; „climbing”- ED50: 16 mg/kg

55

„In vivo

activity”(pharmacodynamics)

„In vitro

activity”„In vivo ADME”(pharmakokinetics)

Receptor binding assay

F

O

NN

NO

H

[3H]

spiperone

56

Receptor binding assay (in vitro)

1. preparation of the receptors

2. addition of the radioligand and the drug

3. incubation

4. filtering

5. measurement

6. evaluation

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58

IC50 is defined as the concentration of the inhibitor causing 50% inhibition of radioligand binding

59

The inhibition constant for a drug; the concentration of competing ligand in acompetition assay which would occupy 50% of the receptors if no radioligandwere present. Whereas the IC50 value for a compound may vary between experiments depending on radioligand concentration, the Ki is an absolute value.It is calculated from the IC50 using the Cheng-Prusoff equation:

where [L] = the concentration of free radioligand used in the assay, and KD = the dissociation constant of the radioligand for the receptor.

Ki

Bioavailability (BA)

60

Bioavailability is a measure of the amount of an administered dosethat reaches the bloodstream.

apomorfin

NH2

HO

OH

dopamin

N

HO

OH

HCH3

Climbing behavior in mice (in vivo)

61

62

Climbing behavior in mice (in vivo)

ED50 is a dose that produces the desired effect in 50per cent of a population.

63

IC50, Ki, BA, ED50

The second project: 1999-2000

Goal: treatment of cocaine abuse

64

BP-897D3-IC50: 0.6 nM; D2-IC50: 115 nM; α-1-IC50: 30 nM

N

O

H

N

N

OMe

65

N

O

H

N

N

OMe

NN

S

2D3-IC50: 1.0 nM; D2-IC50: 584 nM; α-1-IC50: 2829 nM

1D3-IC50: 0.13 nM; D2-IC50: 108 nM; α-1-IC50: 4.3 nM

N

O

H

N

N

NN

S

H

CF3

N

O

H

N

N

OMe

OMe

N

NO

N

N

S

RGH-1756 BP-897

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CHEMICAL STARTING POINT,LEAD COMPOUND

N

O

H

N

N

NN

S

H

CF3

N

XY

N

H

Q

OZ

where Q mostly aromatic carbo- or heterocycle,X means N or CH,Y single bond, O, NH or CH2, while Z may be one or more alkyl, alkoxy, halogen, nitril etc.on any carbon atom of the phenyl ring.

68

The second compound library

Aromatic carboxylic acids272

Cyclic secondary amines46

12512 membered virtual compound library

Synthesis of 480 membered focussed compound library

Pharmacophore screeningCoMFA focussing

Reactivity screening

69

N

XY

N

H

Q

OZ

H

N

O

NN

S

N

N

O

NN

S

N

N

O

NN

S

I

N

O

NN

S

OHN

O

NN

S

OSi

O OMe

NH O

Si

O

CHO

OMe

i

ii

iii

iv

v

vi

i: "primary amine"/NaBH(OAc)3/AcOH; ii: „acid"/HBTU/TEA;

iii: Bu4NF;iv: I2/Ph3P/imidazole;v: "secondary amine", DIPEA;vi: TFA/DKM.

70

N

N

N

CN

O

H

3 (SB-277011)D3-IC50: 6.4 nM, BA: 63%

N

N

N

OMe

O

H

6D3-IC50: 1.3 nM, BA: 16.7%

N

N

CN

O

H

9D3-IC50: 6.7 nM, BA: 4.9%

N

CN

N

N

O

H

4D3-displ.: <<70%, BA: 18%

N

CN

N

N

O

H

7D3-displ.: <<70%, BA: 11%

N

O

N

CN

N

10D3-displ.: <<70%, BA: 54.6%

NS

Cl

O O

H

N

CN

5D3-IC50: 3.4 nM, BA: 80.4%

N

N

N

N

O

H

CF3

H

8D3-IC50: 3.4 nM, BA: 35.5%

N

N

N

N

O

H

H

CF3

11D3-IC50: 4.2 nM, BA: 40.6%

SAR: structure activity relationship

71

NS

Q

O O

H

N

XY

Z

NS

Cl

O O

H

N

CN

5D3-IC50: 3.4 nM, BA: 80.4%

72

Aromatic sulfonyl chlorides28

Cyclic secondary amines46

1288 membered virtual compound library

Syntheses of 288 membered focussed compound library

Pharmacophore screeningCoMFA focussing

Reactivity screening

The third compound library

73

NS

Q

O O

H

N

XY

Z

CHO

OH

NH

Br

NH

Br

NS

Q

O O

N

NS

Q

O O

XY

Z

N

N

H

SQ

O O

XY

i

ii

iii

iv

v

Z

i: trans-4-aminociklohexylethanol/NaBH(OAc)3/CH2Cl2/ AcOH;

ii: PPh3.Br2/imidazole/CH2Cl2; iii: QSO2Cl/TEA/THF;iv: cyclic amine/KI/DMF;v: TFA/CH2Cl2.

74

12D3-IC50: 0.6 nM; D2-IC50: 83 nM

BA: 55%; „climbing”- ED50: 22 mg/kg

NS

HN

O O

N

N

CN

CF3

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LEAD OPTIMIMIZATION

The third project: since 2001

Goal: antipsychotic

77

Starting hypotheses

- Blocking the D2 receptors is necessary.

- Concomitant blocking the dopamin D3 receptors maycause further advantages.

- In order to achieve good pharmacological activitycompounds should bind better to D3 receptors than to D2

receptors.

78

12D3-IC50: 0.6 nM; D2-IC50: 83 nM

BA: 55%; „climbing”- ED50: 22 mg/kg

NS

HN

O O

N

N

CN

CF3

But CYP1A induction and QT prolongation!

79

12D3-IC50: 0.6 nM; D2-IC50: 83 nM

BA: 55%; „climbing”- ED50: 22 mg/kg

NS

HN

O O

N

N

CN

CF3

But CYP1A induction and QT prolongation!

80

„Safetypharmacology”

„In vitro

ADME”

N

N Cl

Cl N

NCF3

N

CF3

N

O CF3

81

„climbing” ED50 < 10 mg/kg

N

N

NS

H

OO

N CH3

O

H

Cl

Cl

N

NS

H

OO

CF3

O

O

HCl

N

N

NS

NH

OO

CF3

3 HCl

N

NS

NH

OO

CF3

2 HCl

13 14

15 16

82

17D3-IC50: 1.9 nM; D2-IC50: 143 nM; α-1-IC50: > 10000 nM;

ind.:1408%; „climbing”- ED50: 1.54 mg/kg

N

N

N

CF3

CN

CH3

O

H

83

NS

HN

O O

N

N

CN

CF3

12

i: PCl5; ii: HCl/EtOAc; iii: TEA/CH2Cl2

N

N

N

SN

H

CF3

CN

O O

N

N

O N

H

CF3

CN

O

N

N

CF3

CN

Cl H3N+-

N

SO3H

N

SO2Cl

i ii

iii

.HCl

84

18D3-IC50: 1.6 nM, D2-IC50: 16 nM, α-1-IC50: 508 nM,

BA: 30%, „climbing”- ED50: 0.27 mg/kg

N

N

NN CH3

HCH3

Cl

Cl

O

Z

N N

H

N

XY

O

R1

R2

( )n

The fourth compound library

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CLINICAL CANDIDATE

Allergan Announces U.S. Availabilityof VRAYLAR™ (cariprazine) forTreatment of Bipolar Mania and Schizophrenia in Adults

DUBLIN, March 16, 2016 /PRNewswire/

Allergan plc (NYSE: AGN), a leading globalpharmaceutical company, announced today thatVRAYLAR™ (cariprazine), a once-daily oral atypicalantipsychotic, is now available by prescription inpharmacies throughout the U.S.

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Budapest, Hungary – 19 July 2017 – Gedeon Richter Plc.("Richter") announces that the European Commission (EC)has granted marketing authorization to Reagila® (cariprazine)a novel antipsychotic for the treatment of schizophreniain adult patients.

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STRUCTURE - MoA/BIOLOGICAL TARGET – ACTIVITY

PDD & TDD

SCREENING CASCADE

IC50, BA, ED50

CHEMICAL STARTING POINT, LEAD COMPOUND

LEAD OPTIMIMIZATION

CLINICAL CANDIDATE