New treatment options for sleep disorders

Novel selective melatonin MT2 receptor agonist in the treatment of insomnia

Gabriella Gobbi, Canada

Orexin receptor antagonists and insomnia treatment: state of the art

Anthony Gotter, US

Development of piromelatine, a novel multimodal sleep medicine

Nava Zisapel, Israel

The brain H3-receptor as a novel therapeutic target for vigilance and sleep-wake disorders Abstract

Jian Sheng Lin , France

Chairs: Gabriella Gobbi and Anton Y. Bespalov

Prevalence insomnia in Canada and Europe

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10

20

30

40

50

Insomnia symptoms Insomnia disorder

40.4%

13.4%

Resp

ondents

(%

)

0

10

20

30

40

50

Insomnia symptoms Insomnia disorder

34.5%

9.8%Resp

ondents

(%

)

1. Morin et al. Can J Psychiatry. 2011;56:540-548; 2. Ohayon et al. Sleep Med. 2009;10:952-960.

Canadian survey1

on sleep and related factors

(N=2000)

European survey2

on insomnia and sleep symptoms

(N=25,579)

Prevalence in the American Insomnia Survey

10,094 members of a managed health care plan

Prevalence 23.6%*

Insomnia symptoms: about 45%

Risk of insomnia higher in: Women vs men

Older age vs younger groups (18-64 vs >65 y)

Disabled or retired vs employed

Shift workers vs day workers

Obese vs normal BMI

Diagnosis based on any one of 3 systems: DSM-IV-TR, ICD-10, RDC/ICSD-2.*Insomnia assessed using Brief Insomnia Questionnaire (BIQ).

Roth et al. Biol Psychiatry. 2011;69:592-600.

Insomnia and Societal Burden

Psychiatric•Increased risks of depression and alcohol dependence1,2

Health•Increased risks of hypertension, metabolic syndrome, and coronary heart disease2

Occupational•Decreased productivity and increased absenteeism1,2

Economic •Increased health care costs1,2

Public safety •Increased risks of accidents1

1. Léger, Bayon. Sleep Med Rev. 2010;14:379-389;

2. Buysse. JAMA. 2013;309:706-716.

DRUG DISCOVERY FOR SLEEP DISORDERS

600 BC: Alcohol as therapeutics

1869

Chloral Hydrate

1903

Barbiturates

1960

Benzodiazepines (chlordiazepoxide)

1986

Benzodiazepine-derivates(zopiclone)

2005

MLT agonist Ramelteon (US)

Circadin (EU)

2014

Orexin antagonists

Important need of novel targets and novel drug discovery

Novel selective melatonin

MT2 partial agonists for

the treatment of insomnia

Gabriella Gobbi, MD, PhD

Neurobiological Psychiatry Unit

Department of Psychiatry, McGill University

Montréal, Canada

Sleep Stages: EEG Features1,2

• High muscle tone

EEG activity:

• Low voltage fast activity in the beta range (15–30 Hz)

Wakefulness

• Transitional stage

• Similar to drowsy waking

EEG activity:

• Frequency begins to slow

• Alpha (8–14 Hz) activity mostly at posterior sites

Light sleepstage 1

• Light sleep

• Low muscle tone, slow rolling eye movements

EEG activity:

• Sleep spindles(7–14 Hz) andK-complexes

• Frequency slows to the theta range (4–8 Hz)

Light sleepstage 2

• Slow-wave sleep (SWS)

EEG activity:

• Strong delta (0.5–4 Hz) activity

• Large amplitude increases

Deep SWSstage 3 & 4

• Rapid eye movement (REM)

• Muscle atonia

• Active dreams

• Rate & variability of autonomic nervous system function

EEG activity:

• Returns to profile similar to wakefulness (low voltage fast activity)

REM

1. Iber et al. AASM manual for the scoring of sleep and associated events. http://www.aasmnet.org/scoringmanual/default.aspx;

2. Brown et al. Physiol Rev. 2012;92:1087-1187.

NREM REM

1. Gander. Sleep in the 24-Hour Society. Lower Hutt, NZ: The Open Polytechnic of New Zealand, 2003;

2. Colten, Altevogt, eds. Sleep Disorders and Sleep Deprivation. 2006; www.nap.edu.

Visualizing Sleep Quantity and Quality

Hypnograms showing distribution of normal sleep

pattern1

Over the course of normal sleep, SWS and REM sleep alternate cyclically2

Schematic representation Normal subject

Common Wisdom: Melatonin and sleep

Melatonin & sleep: Clinical

Melatonin (N-acetyl-5-methoxytryptamine, MLT),synthesized by the pineal gland, has beenreported to have hypnotic effects in humans,although results are still controversial (Brzezinskiet al., 2005; Buscemi et al., 2006).

Controversial studies on the role of melatonin insleep, even if there is a concordance on thesoporific effect and sleep-inducing effects ofmelatonin.

Melatonin & sleep: Animal

Animal studies have demonstrated that MLTreduces time to sleep onset and increases bothNREMS and REMS (Holmes and Sugden, 1982;Mirmiran and Pevet, 1986), both effects beingblocked by the GABAA receptor antagonistsflumazenil and picrotoxin (Wang et al., 2003a).

Other studies showed little or no effect (Maillietet al., 2001; Wang et al., 2003).

MT1 receptor

MT2 receptor

Melatonin and its receptors

c-AMP

PIP-2

c-AMP

PIP-2

Guanylyl

cyclase

MLT1a

MLT1b

Dubocovich et al., Pharm Reviews , 2010

MT1 and MT2 in sleep

Which receptor is involved in sleep?

Lack of sleep studies using selective MT1 or MT2

ligands

Lack of sleep studies in MT1KO and MT2KO.

Ligand-model provides 3D-QSAR and SAR analysisbased on 100s of compounds

Agonist

pharmacophore

3D-QSAR

model

Spadoni G.et al. J. Med. Chem. 1997, 40, 1990

Mor M. et al. J. Med. Chem. 1998, 41, 3831

Rivara S. et al., J. Med. Chem. 2005, 48, 4049Purple: rhodopsin

Green: MT2

Orange MT2 TM5

UCM765 and UCM924: novel MT2 selective partial agonists

Rivara et al., JMC, 2007

UCM 765

N-{2-[(3-methoxyphenyl)phenylamino]ethyl}acetamide

UCM 924

N-{2-[(3-bromophenyl)-(4-fluorophenyl)amino]ethyl}acetamide

Rivara et al., CMC, 2009

Pro-Lead Compound Lead Compound

N-(Substituted-anilino-ethyl)amides

UCM765 and UCM924: novel MT2 selective partial agonists

UCM-765 UCM-924

MT1 (pKi) 8.38

Partial agonist

6.75

Antagonist

MT2 (pKi)10.18

Partial agonist

10.2

Partial agonist

F% (p.o) 0.9

6.3 (23.7%

oral

formulation)

T1/2 (min)44 IV 39 IV

68 PO

Rivara et al., 2007, 2009

LEADPRO-LEAD

UCM765SLEEP RECORDING

Effects of UCM765 on sleep parameters

Ochoa-Sanchez et al., J.Neuroscience, 2011

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Veh 20 40 60

NREM

REM Wakefulness

UCM765 (mg/kg, s.c.)

UCM765 (mg/kg, s.c.) UCM765 (mg/kg, s.c.)

**

**

*

8090

100

* *

Veh 20 40 60

UCM765 (mg/kg, s.c.)

NREM

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* *

Total time Total time

Total timeLatency

Light phase

Dark phase

Light phase

Dark phase

Light phase

Dark phase

+48%

-59%

Ochoa-Sanchez et al., J.Neuroscience, 2011

UCM765 (40 mg/kg) on NREM sleep24 hours analysis

LEAD COMPOUND UCM924SLEEP RECORDINGCOMPARISON WITH

MELATONIN AND NON-SELECTIVE MT1-MT2

MELATONIN (40 mg/kg)

VEH

UCM924 (40 mg/kg)

UCM793 (40 mg/kg)

UCM924, MLT and UCM793 (40 mg/kg) on NREM sleep 24 hours analysis

Ochoa-Sanchez et al, Neuroscience Letters 201421

MLT, UCM793, UCM924, 24 hours analysis (total Time)

Latency to sleep

NREM REM Wakefullness

MLT δ

Non-selective MT1-MT2

MT2 selective

δ

Ochoa-Sanchez et al, Neuroscience Letters 2014

Immunocytochemicallocalization of MT2 receptors

Reticular Thalamus

Ochoa-Sanchez et al., J.Neuroscience, 2011

Reticular thalamic neuronsNREM/SWS

State-dependent activity in thalamic and cortical neurones (from Steriade et al., 1993)

If MT2 receptors are located in the Rt nuclei,

the UCM765 should be able to activate these neurons

Hypothesis

Electrophysiological in vivo recording in reticular thalamic

neurons

DIFFERENTIAL

AMPLITUDE

DISCRIMINATOR

UCM765 increases firing and burst activity of reticular thalamic neurons

MT2 ANTAGONIST 4P-PDOT

The effect of the partial agonist is blocked by the antagonist

H3CH2COCHN

MT2 receptors (pKi = 8.8)

MT1 receptors (pKi = 6.3)

(Dubocovic et al., 1997)

Microinfusion into the reticular thalamic neurons of the MT2 antagonist 4P-PDOT.

4P-PDOT prevents the UCM 765 from increasing firing and burst activity

The pharmacological activation of MT2 receptors promotessleep, in particular NREM or SWS and decrease the latencyto sleep

Melatonin decreases the latency to sleep but not sleepduration

The MT2 receptors are localized in the reticular thalamus,and they promote NREM through the rhythmic and burstactivation of reticular thalamic neurons, which is thehallmark of NREM/SWS.

The MT2 receptor represents a novel target for hypnotics

Conclusion 1

Sleep recording in MT1, MT2 and MT1-MT2 knockout mice

C3H

24 h sleep-wake analysis

Comai et al., Behavior Brain Res, 2013

Sleep recording in MT1, MT2 and MT1-MT2knockout mice

NREM

Tim

e(m

in)

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Light Dark

Total time

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WT -/-MT1-/-MT2

-/-MT1-/-MT2 WT -/-MT1

-/-MT2-/-MT1

-/-MT2

Light Dark

WT -/-MT1-/-MT2

-/-MT1-/-MT2 WT -/-MT1

-/-MT2-/-MT1

-/-MT2

Total time

NREM sleep

4 second period analysis

Comai et al., Behavior Brain Res, 2013

10 second period analysis

NREM decreased in MT2 KO , but increased in MT1 KO

NREM sleep in MT1, MT2 and MT1-MT2knockout mice:

NREM decreases in MT2 KO (light)

Comai et al., Behavior Brain Res, 2013

MT2

MT1

NREM

Opposite effects of MT1 and MT2 receptors in NREM

REM

Light DarkT

ime

(min

)

Total time

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60

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120

WT -/-MT1-/-MT2

-/-MT1-/-MT2 WT -/-MT1

-/-MT2-/-MT1

-/-MT2

Tim

e(m

in)

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60

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Light DarkWT -/-MT1

-/-MT2-/-MT1

-/-MT2 WT -/-MT1-/-MT2

-/-MT1-/-MT2

Total time

REM sleep

no light/dark difference

no light/dark difference

Comai et al., Behavior Brain Res, 2013

4 second period analysis 10 second period analysis

REM decreases only in MT1 KO

Blunted light-dark difference in MT1 KO

REM sleep in MT1, MT2 and MT1-MT2 knockout mice:

REM decreases only in MT1 KO

Comai et al., Behavior Brain Res, 2013

NREM REM WAKEFULNESS

MT1 knockout *

MT2 knockout

MT1-MT2

knockout

(24)

Differential role of receptors

Comai et al., 2013* 10 sec analysis

Conclusion 2

The MT1 and MT2 receptor have a differential role in sleepregulation, this role could explain the relative low effect ofnon-selective MT1-MT2 agonist, including melatonin, andthe lack of significant sleep impairment in double MT1-MT2 knockout

Genetic and pharmacological manipulation of MT2 receptorhas confirmed the selective implication of this receptor inNREM

Pharmacological activation of melatonin MT2

receptors

NREM

Gabriella Gobbi’s lab

EEG/EMG & Electrophysiology, Behaviour, Pain

• Dr Rafael Ochoa Sanchez

• Dr Stefano Comai

• Dr Sergio Dominguez-Lopez

• Dr Francis Rodriguez Bambico

• Dr Quentin Rainer

• Marta Lopez-Canul

Immunohistochemistry

• Dr Baptiste Lacoste

AcknowledgmentsPharmacology and antibodies, Immunohisto

• Franco Fraschini (Univ. of Milan, Italy)

• Deborah Angeloni (Scuola Superiore Sant’Anna, Pisa, Italy)

• Laurent Descarries (Univ. of Montreal, Canada)

Modeling and Synthesis UCM 765

• Giorgio Tarzia (Univ. of Urbino, Italy)

• Gilberto Spadoni (Univ. of Urbino, Italy)

• Annalida Bedini (Univ. of Urbino, Italy)

• Marco Mor (Univ. of Parma, Italy)

• Silvia Rivara (Univ. of Parma, Italy)

Knockout-mice

• David Weaver (Univ. of Massachusset, US)

• Steven Reppert (Univ. of Massachusset, US)

Pain models

• Sabatino Maione (Second Univ. of Naples, Italy)

• Enza Palazzo (Second University of Naples, Italy)

• Vinicio Granados Soto (CINVESTAV, Mexico City, Mexico)

Grants support: CIHR, FRSQ, CFI, MSBiV, MDEIE