Press Release: Addex mGlu2 PAM Program to Advance into Epilepsy Phase 2a Proof of Concept Clinical Study

Study with JNJ-40411813 (ADX71149) will treat first epilepsy patients in

early 2021

Geneva, Switzerland, June 16, 2020 --

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Addex Therapeutics (SIX: ADXN and Nasdaq: ADXN), a clinical-stage

pharmaceutical company pioneering allosteric modulation-based drug

discovery and development, today announced that the selective

metabotropic glutamate type 2 (mGlu2) receptor positive allosteric

modulator (PAM), JNJ-40411813 (ADX71149), will advance into a Phase 2a

proof of concept study in patients with epilepsy. The multi-center study

is scheduled to begin dosing patients in the United States early 2021.

Janssen Pharmaceuticals, Inc., part of the Janssen Pharmaceutical

Companies of Johnson & Johnson, is responsible for the clinical

development and commercialization of JNJ-40411813 (ADX71149) under the

terms of a licensing agreement with Addex.

Glutamate is the primary excitatory neurotransmitter in the brain and

plays a key role in the initiation and spread of seizures. When

activated, the mGlu2 receptor decreases the release of glutamate and

consequently helps to maintain neurotransmitter balance. In the presence

of agonist-induced activation, positive allosteric modulation of mGlu2

receptors could result in the normalization of the excessive glutamate

release seen during a seizure.

"The decision of Janssen to advance ADX71149 into a Phase 2 clinical

study is an exciting development and an important achievement for us,"

said Tim Dyer, CEO of Addex. "Addex now has two active clinical programs

with a number of significant value creating milestones ahead, two major

collaborations with pharma and a pipeline of earlier-stage programs that

are moving rapidly towards the clinic."

The multi-center study will assess the efficacy, safety, tolerability

and pharmacokinetics of adjunctive JNJ-40411813 (ADX71149)

administration in patients with focal onset seizures with suboptimal

response to levetiracetam. The primary objective of the study is to

evaluate the efficacy of JNJ-40411813 (ADX71149) using a time-to-event

endpoint.

"Preclinical studies in epilepsy models have demonstrated a strong

synergistic anti-epileptic effect of ADX71149 and levetiracetam when

given in combination," said Robert Lütjens, Head of Discovery

Biology of Addex. "We are now looking forward to testing this hypothesis

in the clinic, as this represents a completely novel approach based on a

rational polypharmacy concept."

About the Agreement

Under the research collaboration and license agreement, Addex granted

Janssen an exclusive worldwide license to develop and commercialize

mGlu2 PAM compounds. Addex is eligible for up to a total of EUR109

million in success-based development and regulatory milestone payments.

In addition, Addex is eligible for low double-digit royalties on net

sales of compounds developed under the agreement.

About Addex Therapeutics

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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) is being developed in

collaboration with Janssen Pharmaceuticals, Inc for the treatment of

epilepsy. In addition, Addex's GABA(B) PAM program has been licensed to

Indivior PLC for the treatment of addiction. 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

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statements including with respect to the creation of a trading market

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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.

(END) Dow Jones Newswires

June 16, 2020 01:00 ET (05:00 GMT)