Press Release: Addex Receives Additional $2.8 million from Indivior and Extends GABAB PAM Research Collaboration

Geneva, Switzerland, November 2, 2020 - Addex Therapeutics Ltd (SIX and

Nasdaq: ADXN), a leading company pioneering allosteric modulation-based

drug discovery and development, today announced that the research term

of the agreement signed with Indivior PLC (LON: INDV) in January 2018

has been extended until June 30, 2021. The collaboration with Indivior

covers the discovery of novel oral gamma-aminobutyric acid receptor

subtype B (GABA(B) ) positive allosteric modulator (PAM) compounds as

potential therapies for multiple disease areas. As part of the amended

agreement, Indivior has agreed to pay Addex $2.8 million in research

funding and expand the therapeutic areas where Addex has exclusivity to

develop retained compounds.

"The extension of our research collaboration and the additional funding

from Indivior is a clear recognition of the potential of our allosteric

modulator discovery platform and the significant achievements of our

drug discovery team," said Tim Dyer, CEO of Addex. "Indivior is a world

leader in the development of addiction medication and strongly committed

to GABA(B) PAM as a potential treatment for addiction including alcohol

use disorder."

"Although 200 health conditions have been linked to harmful alcohol use,

(1) there are few pharmacotherapies for alcohol use disorder (AUD) --

their ef cacy and uptake in clinical practice are limited, and patient

acceptance is minimal. We are, therefore, very pleased to expand our

partnership with Addex Therapeutics to discover and profile new potent

and selective GABA(B) PAMs and provide a new class of medications that

has the potential to achieve therapeutic benefits in patients suffering

from AUD," said Christian Heidbreder, Chief Scientific Officer of

Indivior.

"Due to the extensive validation of GABA(B) activation with baclofen,

we believe a novel, orally available GABA(B) PAM could provide

significant benefits to patients in many therapeutics areas," said

Jean-Philippe Rocher, Co-Head of Discovery. "We have advanced multiple

novel chemical series' to late stages of lead optimization and we look

forward to rapidly delivering first-in-class compounds for Indivior to

advance into clinical development."

Under the terms of the original agreement signed with

https://www.globenewswire.com/Tracker?data=-YYl-2tZGMa5BFpsV4FkuQ5VQVBZqPFFoq3WE_Mvh3MaEs4BLALI4iR9j2yFmRzd992whyTN7f_p0dO50O1_0i15Yae73byQbZi9LvtN-wVpMVWDz2Cz7_9by7m7auo7qh6OHse76g92IA7ePP7eobKOA0Q-BaE_cgT6jMjVZqM5Aap2Ho7BO_vmRPfJJVCZ763yoJ60b8yFurNM8o6tDMy6Y3B_-PAcPDe41KZ2cyD4Qe46qmA8RY3pEgW7MI5OmVABxY5WntexBSzY3uOR0kJoj7oaJ-HDmTcxlBN_TbU=

Indivior in January 2018, Addex received a $5 million upfront payment

and has since received $5.6 million research funding. Addex is eligible

to receive up to $330 million of development, regulatory and

commercialization milestones as well as tiered royalties up to teen

double-digit. In addition, Addex has the right to retain certain

compounds and pursue their development for reserved indications outside

addiction, including for the treatment of Charcot-Marie-Tooth type 1a

(CMT1A) neuropathy, a rare inherited disorder that affects peripheral

nerves. Addex has discovered novel GABA(B) PAMs and has made

significant progress in optimization of potential drug candidates. Addex

expects to enter clinical candidate selection phase by end of 2020 and

deliver drug candidates for IND enabling studies by the end of 2021 for

both Indivior and for its in-house CMT1A program.

About GABA(B) Activation with PAM

Activation of the GABA(B) receptor, a Family C class of GPCR, is

clinically and commercially validated by the generic GABA(B) receptor

agonist, baclofen which is marketed for spasticity and some spinal cord

injuries. In addition, baclofen is used off label for a number of

disease areas including AUD and overactive bladder, however, its use is

limited due to a variety of side effects and rapid clearance of the

drug. Unlike GABA(B) orthosteric agonists such as baclofen, GABA(B) PAM

only act when the natural ligand (GABA) activates the receptor, and

therefore respect the physiological cycle of activation. Consequently,

its been demonstrated that PAMs are less prone to tolerance and

therefore could produce less adverse effects than direct agonists (May

and Christopoulos 2003; Langmead and Christopoulos 2006; Perdona et al.

2011; Urwyler 2011; Gjoni et al., 2008; Ahnaou et al., 2015).

About Addex Therapeutics

https://www.globenewswire.com/Tracker?data=_HUG5cQQSvGVNihSNLbvz4GOvoIhn154bu_ePUPE_U8C486QTHVRHm7epKMEsqQEVEM8V66mmEaKv2xwMAq_iuhw-nVUn4yo-b74cniObGY=

Addex Therapeutics is a clinical-stage pharmaceutical company focused on

the development and commercialization of an emerging class of novel

orally available small molecule drugs known as allosteric modulators for

neurological disorders. Allosteric modulators offer several potential

advantages over conventional non-allosteric molecules and may offer an

improved therapeutic approach to conventional "orthosteric" small

molecule or biological drugs. Addex's allosteric modulator drug

discovery platform targets receptors and other proteins that are

recognized as essential for therapeutic intervention. Addex's lead drug

candidate, dipraglurant (mGlu5 negative allosteric modulator or NAM), is

scheduled to enter a pivotal registration clinical trial for Parkinson's

disease levodopa induced dyskinesia (PD-LID). In parallel,

dipraglurant's therapeutic use in dystonia is being investigated in

preclinical models. Addex's second clinical program ADX71149 (mGlu2

positive allosteric modulator or PAM), developed in collaboration with

Janssen Pharmaceuticals, Inc., is scheduled to enter a Phase 2a proof of

concept clinical study for the treatment of epilepsy. Preclinical

programs include GABA(B) PAM for CMT1A, mGlu7 NAM for PTSD, mGlu2 NAM

for mild neurocognitive disorders, mGlu4 PAM for Parkinson's disease and

mGlu3 PAM for neurodegenerative disorders.

Press Contacts:

Tim Dyer Mike Sinclair

Chief Executive Officer Partner, Halsin Partners

Telephone: +41 22 884 15 55 +44 (0)20 7318 2955

Email: mailto:PR@addextherapeutics.com PR@addextherapeutics.com mailto:msinclair@halsin.com msinclair@halsin.com

---------------------------------------------------------------- -------------------------------------------------

Forward Looking Statements

Certain statements made in this announcement are forward-looking

statements including with respect to the timing of candidate selection

and delivery of drug candidates under the Indivior agreement and for its

in-house CMT1A program. These forward-looking statements are not

historical facts but rather are based on the Company's current

expectations, estimates, and projections about its industry; its

beliefs; and assumptions. Words such as 'anticipates,' 'expects,'

'intends,' 'plans,' 'believes,' 'seeks,' 'estimates,' and similar

expressions are intended to identify forward-looking statements. These

statements are not guarantees of future performance and are subject to

known and unknown risks, uncertainties, and other factors, some of which

are beyond the Company's control, are difficult to predict, and could

cause actual results to differ materially from those expressed or

forecasted in the forward-looking statements, including clinical and

regulatory developments and the impact of the COVID-19 pandemic. The

Company cautions securityholders and prospective securityholders not to

place undue reliance on these forward-looking statements, which reflect

the view of the Company only as of the date of this announcement. The

forward-looking statements made in this announcement relate only to

events as of the date on which the statements are made. The Company will

not undertake any obligation to release publicly any revisions or

updates to these forward-looking statements to reflect events,

circumstances, or unanticipated events occurring after the date of this

announcement except as required by law or by any appropriate regulatory

authority.

(1) Global status report on alcohol and health 2018. Geneva: World

Health Organization; 2018. Licence: CC BY-NC-SA 3.0 IGO

(END) Dow Jones Newswires

November 02, 2020 01:00 ET (06:00 GMT)