Mikhail Kalinichev
Analyst · H.C. Wainwright
Thanks, Tim. Hello, everyone. I will start by speaking about dipraglurant and our plans for development in brain injury recovery. Following termination of the development of dipraglurant in PD-LID, we embarked on the detailed evaluation of a number of potential indications for future development. We have completed this exercise and have identified brain injury recovery as an interesting indication for the future development. We believe the differentiated profile of dipraglurant makes it particularly suitable for enhancing the impact of rehabilitation in traumatic brain injury and stroke patients. There is a large number -- large unmet medical need in post-stroke recovery and rehabilitation. Stroke is among leading causes of chronic often lifelong disability as it leads to motor sensory cognitive impairment and multiple comorbidities. There are over 100 million stroke survivors worldwide, and the number is growing at the annual rate of 12 million. A variety of rehabilitation therapies are used with post-stroke patients, but the recovery is slow and often inadequate. There is an urgent need for pharmacological agents that can facilitate the recovery stimulated by rehabilitation therapists. mGluR5 receptor is suitable target to address post-stroke recovery as it is densely expressed in the brain involved in neuroplasticity and modulate excitatory-inhibitory equilibrium. In fact, activation of mGluR5 has been observed in range of neurological disorders, including stroke, where it plays a role in so-called maladaptive rewiring of the brain following stroke. Inhibition of mGluR5 on the other hand can facilitate adaptive rewiring of the brain, promoting neuroplasticity and creating of new functional pathways moving the neural network towards the pre-lesion state. Exciting new evidence recently published in the Journal Brain suggests that the negative allosteric modulator of mGluR5 MTEP administered daily in rats following stroke results in a sustained and growing improvement in sensory motor function in comparison to [indiscernible] treatment. Similar improvement in sensory motor function was observed in animals treated with our mGluR5 NAM dipraglurant. MRI imaging of the resting state functional connectivity in post-stroke rodents shows that daily administration of MTEP also stimulates intra and inter-hemispheric connectivity in the brain disrupted by stroke. It is important to note that improvement in brain connectivity after stroke is known to correlate with functional recovery and is observed across species. Dipraglurant is ideally suited to be used in tandem with rehabilitation therapies in post-stroke patients as it has a fast onset of action and short half-life. It has shown good tolerability in healthy subjects and in Parkinsonian patients showing only mild to moderate CNS-related adverse effects. We have a drug product ready and a strong patent position and believe dipraglurant can become a first-in-class drug to facilitate post-stroke recovery. We can also speculate that dipraglurant-mediated adaptive rewiring and facilitation of recovery following brain damage would also be seen in traumatic brain injury patients. Let me now switch to our GABAB positive allosteric modulator program, which is partnered with Indivior. The aim of this collaboration is to deliver a better baclofen for substance use disorders. As a reminder, GABAB receptor activation has been clinically validated in a number of disease areas using baclofen, a GABAB orthosteric agonist. Baclofen is an FDA approved for treatment of spasticity and is widely used off-label to treat numerous diseases, including substance use disorder. However, baclofen has a short half-life and comes with significant side effects, hampering its wider use. Thus, there is a strong need for a better baclofen. We believe that this can be achieved with positive allosteric modulators and their differentiated pharmacology, having the efficacy that is similar or better than that of baclofen but longer half-life and improved side effect profile. Our partner Indivior has selected GABAB PAM drug candidate for development in substance use disorders and has started IND-enabling studies in H2 2024. As part of our agreement with Indivior, Addex has exercised its right to select a compound to advance its own independent GABAB PAM program for the treatment of chronic cough. I will now present this exciting opportunity. There is a strong rationale for developing GABAB PAMs for chronic cough. Chronic cough is a persistent cough that lasts for more than 8 weeks and can be caused by a variety of factors, including respiratory infections, asthma, allergies, and acid reflux, but also possibly by an overactive cough reflux. There is a large unmet medical need in novel antitussive drugs as current standards of care are ineffective in 30% of patients or only moderately affected in up to 60% of patients. In addition, the current treatments carry risks of serious side effects. On the next slide, we show that GABAB PAMs are likely to have a superior tolerability profile in comparison to current standards of care and show no taste-related side effects as seen with a newly approved P2X3 inhibitor Gefapixant. Supports for using GABAB PAM in treatment of chronic cough comes from the clinical evidence that baclofen, a GABAB agonist is used off-label in cough patients and from the anatomical evidence that GABAB receptors are strongly expressed in airways and in the neural pathway regulating cough. Therefore, we believe that GABAB PAMs could offer superior efficacy in cough patients. The pre-IND activities, including in vivo proof-of-concept studies, non-GLP tox and CMC have been completed. Our clinical candidate has shown favorable efficacy, tolerability and developability profile. The compound has demonstrated a consistent minimum effective dose of 1 mg/kg and ED50 of 6 mg/kg in models of cough Indivior. No signs of tolerance were seen after sub-chronic dosing and more than [ 60 mg/kg ] safety margin was demonstrated based on respiratory depression as sedation biomarker. The IND-enabling studies are planned to start this year. The next set of slides describes the in vivo proof-of-concept study in models of cough in guinea pigs where we evaluated efficacy and tolerability of our clinical candidate, Compound A, and also characterized clinically active antitussive drugs, nalbuphine, baclofen, codeine, and the P2X3 inhibitor in the same model. In the model of citric acid induced cough in guinea pigs, acutely administered Compound A, delivered a robust antitussive efficacy reducing the cough number dose dependently and achieving 70% reductions at the maximal dose. The antitussive profile of compound A was similar to that of nalbuphine, baclofen, and codeine. A compound A also increased the latency to first of dose dependently, thus delaying the onset of cough. The antitussive profile of compound A in delaying cough onset was similar or better than that of reference drugs. In the same experiment, compound A appeared well tolerated as there were no marked changes in respiratory rate at up to 60 mg/kg. In contrast, nalbuphine, baclofen and codeine resulted in robust reduction of respiratory rate at their highest dose indicative of sedative like effects. When evaluation of the antitussive efficacy across compounds was done at the respective high doses free from respiratory effects, compound A was shown to be superior to reference drugs in both cough number and cough latency measures. In the chronically administered compound A showed signs of improved efficacy and potency and no signs of tolerance in comparison to an acutely. In the model of ATP potentiated citric acid cough in guinea pigs in a head-to-head comparison experiment, acutely administered compound A exhibited a trend of better efficacy and potency in comparison to that of P2X3 inhibitor while showing signs of similar tolerability. In summary, we have selected a clinical candidate for chronic cough with a robust reproducible antitussive efficacy of 1 mg/kg and good PK/PD. The compound has the potential to have the best-in-disease efficacy and tolerability profile and broad applications in cough patients. The compound showed a favorable developability profile in non-GLP tox studies performed in rats, dogs, and non-human primates. We are on track to start IND-enabling studies this year. This concludes our prepared remarks on the progress of our R&D program. Now I hand it back to Tim.