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. Dipraglurant is an orally available, highly selective mGlu5 negative allosteric modulator, which we believe could improve the outcome of rehabilitation for patients suffering from traumatic brain injury or stroke. The mechanism of action of dipraglurant targets neuroplasticity early in rehabilitation to promote rebuilding of neuronal connections and sensory motor recovery. There is 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 promote the recovery stimulated by rehabilitation therapy. mGlu5 receptor is a suitable target to address post-stroke recovery as it is densely expressed in the brain, involved in neuroplasticity and modulates excitatory-inhibitory equilibrium. In fact, activation of mGlu5 has been observed in a range of neurological disorders, including stroke, where it plays a role in maladaptive rewiring of the brain following stroke. Inhibition of mGlu5, 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 mGlu5, MPEP administered daily in rats following stroke results in a sustained and growing improvement in sensory motor function in comparison to vehicle treatment. Similar improvement in sensory motor function was observed in animals treated with our mGlu5 NAM dipraglurant. MRI imaging of the resting state functional connectivity in post-stroke rodents shows that daily administration of MTEP also stimulates intra and interhemispheric 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 events. 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 turn to GABAB program and the exciting opportunity that it offers to the chronic cough patients. There is a strong rationale for developing GABAB PAM 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 by cough hypersensitivity syndrome. There is a large unmet medical need in novel antitussive drugs as current standards of care are ineffective in 30% of patients and only moderately effective in up to 60% of patients. In addition, the current treatments carry risks of serious side effects. Support for using GABAB positive allosteric modulators in treatment of chronic cough comes from the clinical evidence that baclofen 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 neuronal 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 profiles. The compound has demonstrated a consistent minimum effective dose of 1 mg per kg and ED50 of 6 mg per kg in models of cough in vivo. No signs of tolerance were seen after subchronic dosing and more than 60-fold safety margin was demonstrated based on respiratory depression, a sedation biomarker. The IND-enabling studies are planned and ready to start subject to securing financing. In the model of citric acid-induced cough guinea pig, acutely administered compound A delivered a robust antitussive efficacy, reducing the cough number dose dependently and achieving 70% reductions at the maximal doses. The antitussive profile of compound A was similar to that of nalbuphine, Orvepitant, Baclofen, and Codeine. Compound A increased the latency to first cough 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 per kg. In contrast, Nalbuphine, Orvepitant, Baclofen, and Codeine resulted in robust reductions in respiratory rate at their highest doses, 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 Nalbuphine, Orvepitant, Baclofen, and Codeine in both cough number and cough latency measures. In the model of ATP potentiated citric acid cough in guinea pig 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 per kg and good PK/PD. The compound has the potential to have the best-in-class efficacy and tolerability profile and broad application in cough patients. The compound showed a favorable developability profile in non-GLP tox studies performed in rats, dogs and nonhuman primates. Subject to raising financing, we are ready to start the IND-enabling studies. This concludes our prepared remarks on the progress of our R&D. Now I'll hand it back to Tim.